Image-Guided Interventions E-Book

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2014 BMA Medical Book Awards Highly Commended in Radiology category!

Image-Guided Interventions, a title in the Expert Radiology Series, brings you in-depth and advanced guidance on all of today s imaging and procedural techniques. Whether you are a seasoned interventionalist or trainee, this single-volume medical reference book offers the up-to-the-minute therapeutic methods necessary to help you formulate the best treatment strategies for your patients. The combined knowledge of radiology experts from around the globe provides a broad range of treatment options and perspectives, equipping you to avoid complications and put today's best approaches to work in your practice.

"... the authors and editors have succeeded in providing a book that is both useful, instructive and practical" Reviewed by RAD Magazine, March 2015

  • Formulate the best treatment plans for your patients with step-by-step instructions on important therapeutic radiology techniques, as well as discussions on equipment, contrast agents, pharmacologic agents, antiplatelet agents, and protocols.
  • Make effective clinical decisions with the help of detailed protocols, classic signs, algorithms, and SIR guidelines.
  • Make optimal use of the latest interventional radiology techniques with new chapters covering ablation involving microwave and irreversible electroporation; aortic endografts with fenestrated grafts and branch fenestrations; thoracic endografting (TEVAR); catheter-based cancer therapies involving drug-eluting beads; sacroiliac joint injections; bipedal lymphangiography; pediatric gastrostomy and gastrojejunostomy; and peripartum hemorrhage.
  • Know what to look for and how to proceed with the aid of over 2,650 state-of-the-art images demonstrating interventional procedures, in addition to full-color illustrations emphasizing key anatomical structures and landmarks.
  • Quickly reference the information you need through a functional organization highlighting indications and contraindications for interventional procedures, as well as tables listing the materials and instruments required for each.
  • Access the fully searchable contents, online-only material, and all of the images online at Expert Consult.

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Published 24 June 2013
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EAN13 9781455753970
Language English
Document size 66 MB

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Image-Guided
Interventions
SECOND EDITION
Matthew A. Mauro, MD, FACR
The Ernest H. Wood Distinguished Professor of Radiology and Surgery; Chairman,
Department of Radiology, University of North Carolina School of Medicine, Chapel Hill,
North Carolina
Kieran P.J. Murphy, MB, FRCPC, FSIR
Professor of Radiology, Joint Department of Medical Imaging, University Health Network,
Mount Sinai Hospital, Women's College Hospital, Toronto, Ontario, Canada
Kenneth R. Thomson, MD, FRANZCR
Professor of Radiology, Monash University Faculty of Medicine, Nursing, and Health
Sciences
Director, Radiology Department, Alfred Hospital, Melbourne, Victoria, Australia
Anthony C. Venbrux, MD
Director, Cardiovascular and Interventional Radiology, George Washington University
School of Medicine and Health Sciences, Washington, DC
Robert A. Morgan, MBChB, MRCP, FRCR, EBIR
Consultant, Vascular and Interventional Radiologist, Radiology Department, St. George's
NHS Trust, London, United KingdomTable of Contents
Cover image
Title page
Series Page
Copyright
Dedication
Contributors
Preface
Part 1: Vascular Interventions
Section One: History of Angiography and Intervention
Chapter 1: A Brief History of Image-Guided Therapy
Historical Highlights of Endovascular Therapy
Endovascular Milestones
Summary
Historical Highlights of Nonvascular Image-Guided Therapy
Acknowledgment
Section Two: Vascular Diagnosis
Chapter 2: Noninvasive Vascular Diagnosis
Ultrasonography
Clinical ApplicationsMultidetector Computed Tomographic Angiography
Magnetic Resonance Angiography
Chapter 3: Invasive Vascular Diagnosis
Preprocedural Patient Evaluation and Management
Basic Safety Considerations
Tools
Arterial Access
Venous Access
Imaging
Section Three: Instruments of Intervention
Chapter 4: Diagnostic Catheters and Guidewires
Puncture Needles
Sheath and Dilator Systems
Angiographic Catheters
Angiographic Guidewires
Summary
Chapter 5: Balloon Catheters
Physical Principles of Balloon Dilation
Balloon Materials
Catheter Design
Types of Balloons
Summary
Chapter 6: Stents
Clinical Relevance
Introduction
Balloon-Expandable Stents
Self-Expanding StentsPeripheral Stent-Grafts
Drug-Eluting Stents and Restenosis
Summary
Chapter 7: Thrombectomy Devices
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural AND Follow-Up Care
Chapter 8: Embolic Protection Devices
Evidence of Improved Clinical Outcomes with Protected Carotid Artery Stenting
Embolic Burden of Carotid Artery Stenting
Evolution of Embolic Protection Devices
Advantages and Disadvantages of Various EPD Strategies
Clinical Data: Proximal Embolic Protection Devices
Clinical Data: Distal Embolic Protection Devices
Embolic Protection Devices in Noncarotid Circulation
Conclusions
Chapter 9: Atherectomy Devices
Clinical Relevance
Indications
Contraindications to Atherectomy
Equipment
Technique of Atherectomy
OutcomesComplications
Postprocedure and Follow-Up Medical Therapy
Chapter 10: Embolization Agents
Types of Agents Used
Conclusions
Chapter 11: Aortic Stent-Grafts
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 12: Inferior Vena Cava Filters
Inferior Vena Cava Filter Devices
Chapter 13: Endovascular Laser Therapy
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 14: Intellectual Property ManagementHow to Use This Chapter
Overview of Intellectual Property
Confidential Information and Confidentiality Agreements
Patents
Copyrights
Trademarks
Commercialization
Employment and Consulting Agreements
Acknowledgments
Section Four: Patient Care
Chapter 15: Clinical Vascular Examination
History
Risk Factor Identification and Modification
Physical Examination
Bedside Procedures to Assist with Diagnosis
Correlating Clinical Findings with Probability of Disease
Summary
Chapter 16: Treatment of Medical Emergencies
Introduction
Oversedation
Airway Compromise
Respiratory Distress
Emergency Cardiac/Hemodynamic Events
Contrast Reactions
Chapter 17: Radiation Safety and Protection in the Interventional Fluoroscopy
Environment
Negative Effects of Ionizing Radiation
Management of Patient ExposureManagement of Occupational Exposure
Summary
Chapter 18: Management of Risk Factors for Peripheral Artery Disease
Introduction
Lifestyle Modification
Cigarette Smoking
Hypertension
Dyslipidemia
Diabetes
Chapter 19: Principles of Intraprocedural Analgesics and Sedatives
Techniques for Providing Analgesia and Sedation
Indications and Goals of Analgesia and Sedation
Contraindications to Analgesia and Sedation
Equipment
Precautions for Providing Analgesia and Sedation
Pharmacology of Analgesic and Sedative Agents Commonly Used in Interventional
Radiology
Summary
Chapter 20: Contrast Agents
History
Physiology
Alternatives to Iodinated Contrast Agents
Chapter 21: Principles of Thrombolytic Agents
Biology of the Fibrinolytic System
A Model of Regulated Fibrinolysis
First-Generation Thrombolytic Agents
Second-Generation Thrombolytic Agents
Third-Generation Thrombolytic AgentsDirect Fibrinolytic Agents
Summary
Chapter 22: Antiplatelet Agents and Anticoagulants
Physiology of Blood Clotting
Pathophysiology of Blood Clotting
Antiplatelet Agents
Anticoagulants
New Oral Anticoagulants
Patient Education
Chapter 23: Vasoactive Agents
Adrenergic Receptor Pharmacology
Agents Used to Increase Blood Pressure
Agents Used to Increase Cardiac Output
Agents Used to Lower Blood Pressure
Adrenergic Antagonists
Nitrates
Angiotensin-Converting Enzyme Inhibitors
Other Vasodilators
Chapter 24: Antibiotic Prophylaxis in Interventional Radiology
Introduction
Antibiotic Prophylaxis
Antibiotic Resistance
Antimicrobial Hypersensitivity
Antibiotic Agents
Procedure-Specific Antibiotic Prophylaxis
Valvular Heart Disease
SummarySection Five: Principles of Vascular Intervention
Chapter 25: Angioplasty
Stenting
Clinical Relevance
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 26: Restenosis
Background
Clinical Relevance
Prevention of Restenosis
Endovascular Treatment of Restenosis
Chapter 27: Principles of Arterial Access
Technique
Postprocedural and Follow-Up Care
Chapter 28: Closure Devices
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
ComplicationsPostprocedure Care and Follow-Up
Chapter 29: Principles of Venous Access
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Complications
Section Six: Peripheral Arterial Intervention
Chapter 30: Vascular Anatomy of the Upper Extremity
Vascular Imaging of the Upper Extremity
Arterial Anatomy of the Upper Extremity
Venous System
Chapter 31: Anatomy of the Lower Limb
Compartments of the Lower Limb
Vascular Imaging Techniques in the Lower Limb
Chapter 32: Acute Arterial Occlusive Disease of the Upper Extremity
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 33: Acute Lower Extremity IschemiaIndications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Summary
Chapter 34: Chronic Upper Extremity Ischemia and Revascularization
Subclavian and Brachiocephalic Disease
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Other Disorders of Upper Extremity Arteries
Imaging of Upper Extremity Arteries
Chapter 35: Aortoiliac Revascularization
Epidemiology
History
Indications
Contraindications
Equipment
TechniqueOutcomes
Complications
Postprocedural and Follow-Up Care
Chapter 36: Endovascular Management of Chronic Femoropopliteal Disease
Clinical Presentation
Diagnosis
Treatment
Pharmacotherapy during and after Intervention
Chapter 37: Infrapopliteal Revascularization
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 38: Subintimal Angioplasty
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 39: Management of Extremity Vascular TraumaIndications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 40: Management of Postcatheterization Pseudoaneurysms
Indications
Contraindications
Equipment
Technique
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 41: Endovascular Treatment of Peripheral Aneurysms
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 42: Management of Vascular Arteritides
Imaging
Indications
ContraindicationsEquipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Section Seven: Vascular Malformations
Chapter 43: Congenital Vascular Anomalies: Classification and Terminology
Biological Classification of Congenital Soft-Tissue Vascular Anomalies
Chapter 44: Management of Low-Flow Vascular Malformations
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural And Follow-Up Care
Chapter 45: Management of High-Flow Vascular Anomalies
Introduction
Classification
Conclusions
Section Eight: Abdominal Vascular Intervention
Chapter 46: Abdominal Aorta and the Inferior Vena Cava
Abdominal AortaInferior Vena Cava
Chapter 47: Aortic Endografting
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes and Complications
Postprocedural and Follow-Up Care
Chapter 48: Fenestrated Stent-Grafting of Juxtarenal Aortic Aneurysms
Introduction
Indications and Anatomic Suitability
Contraindications
Devices
Procedure Planning
Technique of Stent Insertion
Complications and Outcomes
Postprocedure Care and Follow-Up
Chapter 49: Management of Thoracoabdominal Aneurysms by Branched Endograft
Technology
Introduction
Philosophy
Special Considerations
Technique
Outcomes
Conclusions
Chapter 50: Endoleaks: Classification, Diagnosis, and TreatmentClinical Relevance
Definition
Classification of Endoleaks
Significance and Incidence of Endoleaks
Diagnosis of Endoleaks
Alternative Follow-Up Possibilities
Sequencing of Follow-Up after EVAR
Management of Endoleaks
Summary
Chapter 51: Endovascular Treatment of Dissection of the Aorta and Its Branches
Introduction
Indications for Intervention
Conclusions
Chapter 52: Alimentary Tract Vasculature
Clinical Relevance
Vascular Imaging of the Alimentary Tract
Arterial Supply
Venous System
Liver Vasculature
Biliary System Vasculature
Spleen Vasculature
Pancreas Vasculature
Chapter 53: Management of Upper Gastrointestinal Hemorrhage
Diagnosis
Management
Indications
Contraindications
EquipmentTechnique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 54: Management of Lower Gastrointestinal Bleeding
Clinical Relevance
Indications
Contraindications
Equipment
Anatomy and Approach
Technical Aspects
Controversies
Outcomes
Complications
Postprocedure and Follow-Up Care
Summary
Chapter 55: Acute Mesenteric Ischemia
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 56: Chronic Mesenteric Ischemia
IndicationsContraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 57: Renal Vasculature
Introduction
Renal Vascular Anatomy
Adrenal Suprarenal Vasculature
Vascular Imaging of Kidneys and Adrenal Glands
Chapter 58: Renovascular Interventions
Epidemiology
Clinical Indications
Technical Details
Complications
Distal Embolic Protection
Reported Outcomes and Predictors
Transplant Renal Artery Stenosis
Conclusions
Chapter 59: Acute Renal Ischemia
Indications
Contraindications
Equipment
Technique
Controversies
OutcomesComplications
Postprocedural and Follow-Up Care
Chapter 60: Renal Artery Embolization
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 61: Management of Renal Angiomyolipoma
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 62: Transvenous Renal Biopsy
Clinical Relevance
Indications
Relative Contraindications
Equipment
TechniqueOutcomes
Complications
Postprocedure and Follow-Up Care
Conclusions
Chapter 63: Transjugular Liver Biopsy
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 64: Chemoembolization for Hepatocellular Carcinoma
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Complications
Outcomes
Controversies
Chapter 65: Radioembolization for Hepatocellular Carcinoma
Introduction
Yttrium-90 (90Y) Radioactive Microspheres
Patient Selection and Preparation
ContraindicationsEquipment
Technique
Clinical Outcomes
Postprocedure and Follow-Up Care
Radiolabeled Lipiodol
Conclusions
Chapter 66: Embolotherapy for the Management of Liver Malignancies Other Than
Hepatocellular Carcinoma
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 67: Radioembolization of Liver Metastases
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 68: Bland Embolization for Hepatic Malignancies
IndicationsContraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 69: Portal Vein Embolization
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Postprocedural and Follow-Up Care
Complications
Chapter 70: Vascular Intervention in the Liver Transplant Patient
Technical Features
Arterial Complications
Portal Complications
Caval Complications
Biliary Complications
Chapter 71: Management of Trauma to the Liver and Spleen
Indications
Contraindications
Equipment
Technique
ControversiesOutcomes
Complications
Postprocedural and Follow-Up Care
Chapter 72: Splenic Embolization in Nontraumatized Patients
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 73: Management of Visceral Aneurysms
Indications
Contraindications
Technique
Controversies
Complications
Postprocedural and Follow-Up Care
Chapter 74: Intraarterial Ports for Chemotherapy
Regional Chemotherapy for Liver Tumors
Locoregional Chemotherapy for Gynecologic Pelvic Cancer
Section Nine: Pelvic Vascular Intervention
Chapter 75: Vascular Anatomy of the Pelvis
Arteries
VeinsChapter 76: Uterine Fibroid Embolization
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Periprocedure and Follow-Up Care
Chapter 77: Peripartum Hemorrhage
Introduction
Pathophysiology
Imaging
Indications
Contraindications
Methods and Materials
Arteriogram and Embolization
Preoperative Intraarterial Balloon Placement
Additional or Adjuvant Therapies
Outcomes of Endovascular Therapies
Complications
Chapter 78: Management of Pelvic Hemorrhage in Trauma
Indications
Contraindications
Equipment
Technique
Controversies and Special Considerations
OutcomesComplications
Postprocedural and Follow-Up Care
Chapter 79: Management of Male Varicocele
Introduction
Incidence
Diagnosis
Indications
Contraindications
Equipment
Technique
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 80: Management of Female Venous Congestion Syndrome
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Equipment
Controversies
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 81: Treatment of High-Flow Priapism and Erectile Dysfunction
Priapism
Erectile Dysfunction
Relevant AnatomyTreatment of High-Flow/Nonischemic/Arterial Priapism
Cavernosometry and Cavernosography
Internal Pudendal Angiography and Angioplasty in Erectile Dysfunction
Section Ten: Thoracic Vascular Intervention
Chapter 82: Vascular Anatomy of the Thorax, Including the Heart
Systemic Arteries
Systemic Veins
Pulmonary Vessels
Lymphatic Drainage
Chapter 83: Thoracic Aortic Stent-Grafting and Management of Traumatic Thoracic
Aortic Lesions
Indications
Contraindications
Preoperative Evaluation
Anatomy and Approach
Equipment
Technique
Postprocedural and Follow-Up Care
Pivotal Trials
Controversies
Outcomes
Summary
Chapter 84: Bronchial Artery Embolization
Indications
Contraindications
Equipment
Technique
OutcomesComplications
Postprocedural and Follow-Up Care
Chapter 85: Pulmonary Arteriovenous Malformations: Diagnosis and Management
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 86: Percutaneous Interventions for Acute Pulmonary Embolism
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural Anticoagulation and Follow-Up Care
Section Eleven: Neurovascular and Head and Neck Intervention
Chapter 87: Craniocervical Vascular Anatomy
Craniocervical Arteries
Craniocervical Veins
Chapter 88: Arterial Anatomy of the Spine and Spinal Cord
Introduction
Developmental AnatomyIntrinsic Arterial Vascularization
Spinal Angiography
Chapter 89: Use of Skull Views in Visualization of Cerebral Vascular Anatomy
Chapter 90: Cerebral Functional Anatomy and Rapid Neurologic Examination
Review of Cerebral Circulation
Rapid Neurologic Assessment
The 60-Second Neurologic Examination
Summary
Chapter 91: Carotid Revascularization
Indications
Contraindications
Equipment
Technique
Periprocedural Management
Complications
Follow-Up Care
Outcomes
Conclusions
Chapter 92: Acute Stroke Management
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up CareChapter 93: Endovascular Management of Chronic Cerebral Ischemia
Indications
Contraindications
Equipment
Technique
Controversies
Complications
Postprocedural and Follow-Up Care
Chapter 94: Management of Head and Neck Tumors
Indications for Endovascular Therapy of Benign Head/Neck Lesions
Indications for Endovascular Therapy of Malignant Head/Neck Cancer
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 95: Endovascular Management of Epistaxis
Clinical Relevance
Treatment Options
Indications
Contraindications
Equipment
Embolization
Technique
Complications
Postprocedural and Follow-Up CareSummary
Chapter 96: Subarachnoid Hemorrhage
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 97: Management of Head and Neck Injuries
Indications
Contraindications
Equipment
Technique: Epistaxis, Facial Fractures
Technique: CCA, ICA, and VA Dissections, Pseudoaneurysms, and Transections
Postprocedural and Follow-Up Care
Chapter 98: Cervical Artery Dissection
Clinical Presentation
Diagnostic Testing
Etiology
Management of Acute Cervical Artery Dissection
Long-Term Management of Dissecting Aneurysms and Persistent Stenosis
Summary
Section Twelve: Venous Intervention
Chapter 99: Superior Vena Cava Occlusive Disease
Malignant ObstructionBenign Obstruction
Indications for Intervention
Contraindications
Equipment
Technique
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 100: Percutaneous Management of Chronic Lower Extremity Venous
Occlusive Disease
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 101: Acute Lower Extremity Deep Venous Thrombosis
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 102: Acute Upper Extremity Deep Venous ThrombosisIndications
Clinical Presentation
Imaging Techniques
Contraindications
Equipment
Technique
Controversies
Complications
Postprocedural and Follow-Up Care
Chapter 103: Portal-Mesenteric Venous Thrombosis
Etiology
Clinical Presentation
Prognosis
Imaging
Treatment
Chapter 104: Caval Filtration
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 105: Ambulatory Phlebectomy
Clinical Relevance
Indications
ContraindicationsAnatomy
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 106: Great Saphenous Vein Ablation
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 107: Foreign Body Retrieval
Introduction
Snares
Lost Guidewire and Catheter Fragments
Lost Endovascular Stents
Wires Caught on Inferior Vena Cava Filters
Knotted Catheter
Lost Embolization Coils
Lost Non-Radiopaque Foreign Bodies
Subclavian Arterial Central Venous Catheter
Air Embolism
SummarySection Thirteen: Venous Sampling for Endocrine Disease
Chapter 108: Renal Vein Renin Sampling
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 109: Adrenal Venous Sampling
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 110: Parathyroid Venous Sampling
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up CareChapter 111: Arteriography and Arterial Stimulation with Venous Sampling for
Localizing Pancreatic Endocrine Tumors
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Section Fourteen: Intervention in Portal Hypertension
Chapter 112: Transjugular Intrahepatic Portosystemic Shunts
Pathophysiology of Portal Hypertension
Treatment of Portal Hypertension
Indications
Alternatives to Transjugular Intrahepatic Portosystemic Shunt
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 113: Retrograde Balloon Occlusion Variceal Ablation
Indications
Contraindications
Equipment
TechniqueControversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Section Fifteen: Hemodialysis Access Management
Chapter 114: Surveillance of Hemodialysis Access
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 115: Management of Failing Hemodialysis Access
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 116: Management of Clotted Hemodialysis Access Grafts
Indications
Contraindications
EquipmentTechnique
Controversies
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 117: Percutaneous Management of Thrombosis in Native Hemodialysis
Shunts
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Controversies
Complications
Postprocedure and Follow-Up Care
Section Sixteen: Venous Access
Chapter 118: Peripherally Inserted Central Catheters and Nontunneled Central Venous
Catheters
Indications
Contraindications
Equipment
Technique
Pediatric Considerations
Controversies
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 119: Tunneled Central Venous CathetersIndications
Contraindications
Equipment
Technique
Complications
Postprocedure and Follow-Up Care
Chapter 120: Subcutaneous Ports
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 121: Hemodialysis Access: Catheters and Ports
Introduction
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 122: Clinical Manifestations of Lymphatic Disease
Lymphatic System AnatomyLymphatic System Physiology
Manifestations of Lymphatic Disease
Diagnostic Evaluation of Lymphatic Disease
Chapter 123: Bipedal Lymphangiography
Introduction
Equipment
Technique
Chapter 124: Thoracic Duct Embolization for Postoperative Chylothorax
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Part 2: Nonvascular Interventions
Section Seventeen: Percutaneous Biopsy and Drainage
Chapter 125: Biopsy Devices
Clinical Relevance
Soft-Tissue Biopsy Devices
Comparison of Biopsy Devices
Breast Biopsy Devices
Musculoskeletal Biopsy Devices
Transvenous Biopsy Devices
Pleural Biopsy Devices
Magnetic Resonance Imaging–compatible Biopsy Devices“Treated Needles”
Chapter 126: Percutaneous Biopsy
Indications
Contraindications
Technique
Complications
Postprocedural and Follow-Up Care
Summary
Chapter 127: Percutaneous Abscess Drainage Within the Abdomen and Pelvis
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 128: Management of Fluid Collections in Acute Pancreatitis
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Section Eighteen: The Gastrointestinal TractChapter 129: Esophageal Intervention in Malignant and Benign Esophageal Disease
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 130: Intervention for Gastric Outlet and Duodenal Obstruction
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 131: Preoperative and Palliative Colonic Stenting
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 132: Gastrostomy and GastrojejunostomyIndications
Contraindications
Equipment
Gastrostomy
Gastrojejunostomy
Chapter 133: Pediatric Gastrostomy and Gastrojejunostomy
Introduction
Indications
Contraindications
Assessment
Technique
Postprocedure Care
Technical Aspects Specific to Children
Complications
Outcomes and Follow-Up
Tube Maintenance
New Developments
Section Nineteen: The Biliary Tract
Chapter 134: Management of Malignant Biliary Tract Obstruction
Indications
Contraindications
Equipment
Technique
Outcomes
Complications
Chapter 135: Management of Benign Biliary Strictures
IntroductionIndications
Contraindications
Equipment
Technique
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 136: Management of Biliary Leaks
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 137: Percutaneous Cholecystostomy
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Equipment
Controversies
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 138: Management of Biliary CalculiClinical Relevance
Indications
Contraindications
Equipment
Technique
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 139: Biliary Complications Associated with Liver Transplantation
Surgical Anatomy of the Biliary Anastomosis
Biliary Complications
Section Twenty: General Considerations in Energy-Based Ablation
Chapter 140: Image-Guided Thermal Tumor Ablation: Basic Science and Combination
Therapies
Understanding Tumor Ablation: An Overview
Principles of Tissue Heating in Thermal Ablation
Advances in Radiofrequency Ablation: A Model for Technologic Evolution
Modification of the Biophysiologic Environment
Rationale for Combining Thermal Ablation with Other Therapies
Improving Image Guidance and Tumor Targeting
Conclusions
Section Twenty-One: The Liver
Chapter 141: Energy-Based Ablation of Hepatocellular Cancer
Pretreatment Evaluation
Treatment of Early-Stage Hepatocellular Carcinoma
Technical Aspects
ContraindicationsOutcomes
Postprocedure and Follow-Up Care
Chapter 142: Energy-Based Ablation of Other Liver Lesions
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 143: Cryoablation of Liver Tumors
Indications
Contraindications
Equipment
Technique
Outcomes
Complications
Cryoablation Versus Radiofrequency Ablation
Postprocedural and Follow-Up Care
Chapter 144: Chemical Ablation of Liver Lesions
Chemical Ablation of Benign Liver Lesions
Chemical Ablation of Malignant Liver Lesions
Section Twenty-Two: The Genitourinary Tract
Chapter 145: Urodynamics
Indications
ContraindicationsEquipment
Technique
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 146: Percutaneous Nephrostomy, Cystostomy, and Nephroureteral Stenting
Percutaneous Nephrostomy and Nephroureteral Stenting
Suprapubic Cystostomy
Chapter 147: Renal and Perirenal Fluid Collection Drainage
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 148: Thermal Ablation of Renal Cell Carcinoma
Ablation Devices
Indications
Contraindications
Technique
Complications
Follow-Up Care
Outcomes
Chapter 149: Magnetic Resonance–Guided Focused Ultrasound Treatment of Uterine
Leiomyomas
IndicationsContraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Summary
Chapter 150: Fallopian Tube Interventions
Fallopian Tube Recanalization
Fallopian Tube Embolization
Section Twenty-Three: The Thorax
Chapter 151: Thermal Ablation of the Adrenal Gland
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 152: Percutaneous Biopsy of the Lung, Mediastinum, and Pleura
Indications
Contraindications
Equipment
Technique
ControversiesOutcomes
Complications
Postprocedural and Follow-Up Care
Chapter 153: Treatment of Effusions and Abscesses
Indications
Contraindications
Equipment
Technique
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 154: Lung Ablation
Basic Biophysics of Lung Ablation
Experience to Date
Newly Introduced Advances in Thermal Lung Ablation
Current Role of Thermal Ablation Therapy in Lung Cancer
Chapter 155: Minimally Invasive Image-Guided Breast Biopsy and Ablation
Introduction
Stereotactic Interventions
Ultrasound-Guided Interventions
Biopsy Devices
Lesion Retrieval and Radiologic-Pathologic Concordance
Postbiopsy Care, Contraindications, Complications, Practical Approaches to
Biopsy, and Procedure Discussion with Patient
Contraindications
Complications
Practical Approaches to Biopsy
Ablation TechniquesConclusions
Chapter 156: Tracheobronchial Interventions
Tracheobronchial Balloon Dilation
Equipment
Tracheobronchial Metallic Stent Placement
Section Twenty-Four: The Musculoskeletal System
Chapter 157: Image-Guided Percutaneous Biopsy of Musculoskeletal Lesions
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 158: Ablation and Combination Treatments of Bony Lesions
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 159: Vertebroplasty and Kyphoplasty
IndicationsContraindications
Preprocedural Workup
Technique
Special Topics
Complications
Postprocedural and Follow-Up Care
Chapter 160: New Directions in Bone Materials
Clinical Relevance
Indications
Contraindications
Cements
Polymethyl Methacrylate Cements
Outcomes
Complications
Postprocedure and Follow-Up Care
Acknowledgment
Chapter 161: Minimally Invasive Disk Interventions
Introduction
Pathogenesis of Low Back Pain
Indications and Contraindications
Choice of Radiologic Guidance
Technique
Chapter 162: Chemical and Thermal Ablation of Desmoid Tumors
Chemical Ablation
Thermal Ablation
Section Twenty-Five: Percutaneous Pain Management
Chapter 163: Selective Nerve Root BlockIntroduction
History
Anatomy
Indications
Mapping
Diagnostic Imaging
Contraindications
Drugs Used for Selective Nerve Root Block
Technique
Outcomes
Complications
Patient Selection
Medications
Preprocedure Care
Procedure Care
Postprocedure Care
Potential Complications
Case Studies
Chapter 164: Stellate Ganglion Block
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Outcomes
Complications
Postprocedure Care and Follow-Up
Future ApplicationsChapter 165: Facet Joint Injection
Clinical Relevance
Indications
Contraindications
Equipment
Technique
Outcomes
Complications
Postprocedure and Follow-Up Care
Chapter 166: Sacroiliac Joint Injections
Clinical Relevance
Indications9-13
Contraindications
Equipment9-13
Technique
Technical Aspects
Controversies
Outcomes9,11,14-16
Complications9-13
Postprocedural and Follow-Up Care
Chapter 167: Periradicular Therapy
Perineural, Epidural, and Foraminal Pain Injections
General Inclusion, Exclusion, and Contraindications Criteria
Equipment and Technique
Chapter 168: Epidural Steroid Injection
Clinical Relevance
Indications
ContraindicationsEquipment
Technique
Outcomes
Complications
Postprocedure Care and Follow-Up
Chapter 169: Image-Guided Intervention for Symptomatic Tarlov Cysts
Indications
Contraindications
Equipment
Technique
Controversies
Outcomes
Complications
Postprocedural and Follow-Up Care
Chapter 170: Scalene Blocks and Their Role in Thoracic Outlet Syndrome
Indications
Contraindications
Equipment
Technique
Outcomes
Complications
Postprocedural and Follow-Up Care
IndexSeries Page
Other Volumes in the Expert Radiology Series
Abdominal Imaging
Breast Imaging
Cardiovascular Imaging
Gynecologic Imaging
Imaging of the Brain
Imaging of the Chest
Imaging of the Musculoskeletal System
Imaging of the Spine
Obstetric ImagingC o p y r i g h t
1600 John F. Kennedy Blvd.
Ste 1800
Philadelphia, PA 19103-2899
IMAGE-GUIDED INTERVENTIONS (A Volume in the Expert Radiology Series) ISBN:
978-1-4557-0596-2
Copyright © 2014, 2008 by Saunders, an imprint of Elsevier Inc.
Chapter 111: “Arteriography and Arterial Stimulation with Venous Sampling for
Localizing Pancreatic Endocrine Tumors” by Anthony W. Kam, Bradford J. Wood,
and Richard Chang is in the Public Domain.
Chapter 151: “Thermal Ablation of the Adrenal Gland” by Deepak Sudheendra and
Bradford J. Wood is in the Public Domain.
No part of this publication may be reproduced or transmitted in any form or by any
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This book and the individual contributions contained in it are protected under
copyright by the Publisher (other than as may be noted herein).
Notices
Knowledge and best practice in this field are constantly changing. As new
research and experience broaden our understanding, changes in research
methods, professional practices, or medical treatment may become
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and knowledge in evaluating and using any information, methods,compounds, or experiments described herein. In using such information or
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Library of Congress Cataloging-in-Publication Data
Image-guided interventions / Matthew A. Mauro … [et al.].—2nd ed.
  p. ; cm.—(Expert radiology series)
 Includes bibliographical references and index.
 ISBN 978-1-4557-0596-2 (hardcover : alk. paper)
 I. Mauro, Matthew A., 1951- II. Series: Expert radiology series.
 [DNLM: 1. Radiography, Interventional–methods. 2. Diagnostic Techniques,
Surgical. 3. Vascular Diseases–radiography. 4. Vascular Diseases–therapy. 5. 
Vascular Surgical Procedures–methods. WN 200]
 616.1′307572–dc23
2012046151
Content Strategist: Helene Caprari
Senior Content Development Specialist: Jennifer Shreiner
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Printed in China
Last digit is the print number: 9 8 7 6 5 4 3 2 D e d i c a t i o n
To Pat, my wife, for her unwavering love and support and to our children, Lauren and
David, my most precious accomplishments
Matt Mauro
To Rulan, my wife, Ronan and Anya, the three most interesting people I know in the
world, thank you for allowing me the time and space to work on this book and all my
other crazy ideas. To everyone who has taken the time to teach me, thank you for
your patience
Kieran Murphy
To my wife, Barbara
Ken Thomson
To my family; to my patients, who have taught me so much; to my mentors; and to
Michael Heinl
Tony Venbrux
To my family and friends for their forbearance, support, and good cheer over the years
Robert MorganC o n t r i b u t o r s
Hani H. Abujudeh, MD, MBA
Associate Professor of Radiology
Massachusetts General Hospital
Harvard Medical School
Boston, Massachusetts
Acute Lower Extremity Ischemia
Andreas Adam, PhD, FRCP, FRCS, FRCR
Professor
Department of Interventional Radiology
King's College
Consultant Radiologist
St. Thomas' Hospital
London, United Kingdom
Esophageal Intervention in Malignant and Benign Esophageal Disease
Allison S. Aguado, MD
Fellow
Department of Radiology
Memorial Sloan-Kettering Cancer Center
New York, New York
Embolotherapy for the Management of Liver Malignancies Other Than Hepatocellular
Carcinoma
Muneeb Ahmed, MD
Assistant Professor of Radiology
Section of Interventional Radiology
Harvard Medical School
Beth Israel Deaconess Medical Center
Boston, Massachusets
Image-Guided Thermal Tumor Ablation: Basic Science and Combination Therapies
Kamran Ahrar, MD
Professor
Departments of Diagnostic Radiology and Thoracic and Cardivascular Surgery
University of Texas MD Anderson Cancer Center
Houston, TexasThermal Ablation of Renal Cell Carcinoma
Andrew Akman, MD
Assistant Professor of Radiology
Interventional Radiology
George Washington University School of Medicine and Health Sciences
Washington, DC
Management of Male Varicocele
Morvarid Alaghmand, MD
Internist
Riverside Primary Care Associates
District Heights, Maryland
Alimentary Tract Vasculature
Renal Vasculature
Ali Albayati, MBChB
Fellow
Division of Cardiovascular and Interventional Radiology
George Washington University Medical Center
Washington, DC
Principles of Intraprocedural Analgesics and Sedatives
Management of Male Varicocele
Agaicha Alfidja, MD
Faculty of Medicine
University Hospital
Clermont-Ferrand, France
Acute Mesenteric Ischemia
Ziyad Al-Otaibi, MD
Department of Anesthesiology and Critical Care Medicine
George Washington University Medical Canter
Washington, DC
Treatment of Medical Emergencies
John F. Angle, MD
Professor
Department of Radiology and Medical Imaging
Director
Division of Angiography and Interventional Radiology
University of Virgina Health System
Charlottesville, Virginia
Balloon Catheters
Closure Devices
Tracheobronchial InterventionsGary M. Ansel, MD, FACC
Director, Center for Critical Limb Care
Riverside Methodist Hospital
Columbus, Ohio
Assistant Clinical Professor of Medicine
Medical University of Ohio
Toledo, Ohio
Chronic Upper Extremity Ischemia and Revascularization
Julien Auriol, MD
Praticien Hospitalier
Service de Radiologie
L'Hôpital Rangueil
Universitaire de Toulouse
Toulouse, France
Vascular Intervention in the Liver Transplant Patient
Chad Baarson, DO
Department of Radiology
National Capital Consortium
Walter Reed National Military Medical Canter
Bethesda, Maryland
Bipedal Lymphangiography
Juan Carlos Baez, MD
Resident
Department of Radiology
Brigham and Woman's Hospital
Boston, Massachusetts
Subarachnoid Hemorrhage
Image-Guided Intervention for Symptomatic Tarlov Cysts
Scalene Blocks and Their Role in Thoracic Outlet Syndrome
Curtis W. Bakal, MD, MPH
Chair, Radiology
Lahey Clinic
Burlington, Massachusetts
Professor of Radiology
Tufts University School of Medicine
Boston, Massachusetts
Diagnostic Catheters and Guidewires
Jörn O. Balzer, MD, PhD
Director
Department of Radiology and Nuclear MedicineCatholic Clinic Mainz
Mainz, Germany
Endovascular Laser Therapy
Alex M. Barnacle, MRCP, FRCR
Consultant Interventional Radiologist
Department of Radiology
Great Ormond Street Hospital for Children
London, United Kingdom
Management of High-Flow Vascular Anomalies
Bradley P. Barnett, MD, PhD
Research Fellow
Department of Radiology
Johns Hopkins Medical Institutions
Baltimore, Maryland
Craniocervical Vascular Anatomy
Gamal Baroud, PhD
Professor
Department of Mechanical Engineering
Director, Biomechanics Laboratory
Canada Research Chair in Skeletal Reconstruction
University of Sherbrooke
Sherbrooke, Quebec, Canada
New Directions in Bone Materials
Carlo Bartolozzi, MD
Professor
Diagnostic and Interventional Radiology
University of Pisa
Pisa, Italy
Energy-Based Ablation of Hepatocellular Cancer
Jason R. Bauer, MD, RVT
Director of Interventional Oncology
Interventional and Vascular Consultants, PC
Portland, Oregon
Embolization Agents
Richard A. Baum, MD, MPA
Director, Interventional Radiology
The Herbert L. Abrams Director of Angiography and Interventional Radiology
Brigham and Women's Hospital
Associate Professor
Department of RadiologyHarvard Medical School
Boston, Massachusetts
Thoracic Duct Embolization for Postoperative Chylothorax
Kevin W. Bell, MBBS, FRANZCR
Clinical Associate Professor of Radiology
University of Melbourne Faculty of Medicine
Director
Department of Radiology
Western Health
Melbourne, Victoria, Australia
Vascular Anatomy of the Thorax, Including the Heart
Jacqueline A. Bello, MD
Professor
Departments of Radiology and Neurosurgery
Albert Einstein College of Medicine
Director of Neuroradiology
Department of Radiology
Montefiore Medical Center
Bronx, New York
Management of Head and Neck Tumors
Jennifer Berkeley, MD, PhD
Neurointensivist
Department of Neurology
Sinai Hospital of Baltimore
Baltimore, Maryland
Cervical Artery Dissection
Michael A. Bettmann, MD, FACR
Professor of Radiology Emeritus
Wake Forest University School of Medicine
Winston-Salem, North Carolina
Co-Chair
Task Force on Imaging Decision Support
American College of Radiology
Reston, Virginia
Contrast Agents
José I. Bilbao, MD, PhD
Professor of Radiology
Universidad de Navarra
Consultant Radiologist
Clínica Universitaria de NavarraPamplona, Spain
Portal-Mesenteric Venous Thrombosis
Deniz Bilecen, MD, PhD
Chief
Department of Radiology
Kantonsspital Laufen
Laufen, Switzerland
Transjugular Liver Biopsy
Tiago Bilhim, MD
Interventional Radiologist
Department of Radiology
St. Louis Hospital
Faculty of Medical Sciences
New University of Lisbon
Lisbon, Portugal
Treatment of High-Flow Priapism and Erectile Dysfunction
Christoph A. Binkert, MD, MBA
Chairman of Radiology
Institute of Radiology
Kantonsspital Winterthur
Winterthur, Switzerland
Inferior Vena Cava Filters
Caval Filtration
Haraldur Bjarnason, MD
Professor of Radiology
Division of Vascular and Interventional Radiology
Mayo Clinic
Rochester, Minnesota
Acute Lower Extremity Deep Venous Thrombosis
James H. Black, III, MD, FACS
Bertram M. Bernheim, MD Associate
Professor of Surgery
Johns Hopkins University School of Medicine
Baltimore, Maryland
Clinical Vascular Examination
Brian M. Block, MD, PhD
President
Baltimore Spine Center
Towson, Maryland
InstructorDepartment of Anesthesiology and Critical Care Medicine
Johns Hopkins University School of Medicine
Baltimore, Maryland
Stellate Ganglion Block
Facet Joint Injection
Epidural Steroid Injection
Scalene Blocks and Their Role in Thoracic Outlet Syndrome
Marc Bohner, PhD
Material Science Engineer
Dr. Robert Mathys Foundation
Bettlach, Switzerland
New Directions in Bone Materials
Amman Bolia, MBChB, DMRD, FRCR
Consultant Vascular Radiologist
Departments of Imaging and Interventions
University Hospital of Leicester NHS Trust
Leicester, United Kingdom
Subintimal Angioplasty
Irene Boos, VMD
Clinical Research
Interventional Radiology
Woerth, Germany
Intraarterial Ports for Chemotherapy
Charles F. Botti, Jr., MD, FACC
Cardiac and Peripheral Vascular Interventionist
MidOhio Cardiology and Vascular Consultants
Riverside Methodist Hospital
Columbus, Ohio
Chronic Upper Extremity Ischemia and Revascularization
Nina M. Bowens, MD
General Surgery Resident
Department of Surgery
Hospital of the University of Pennsylvania
Philadelphia, Pennsylvania
Thoracic Aortic Stent-Grafting and Management of Traumatic Thoracic Aortic Lesions
Louis Boyer, MD, PhD
Professor of Radiology
Faculty of Medicine
ISIT, UMR CNRS 6284 University D'Auvergne
Head, Department of RadiologyUniversity Hospital
Clermont-Ferrand, France
Acute Mesenteric Ischemia
Elena Bozzi, MD
Department of Diagnostic and Interventional Radiology
University of Pisa
Pisa, Italy
Energy-Based Ablation of Hepatocellular Cancer
Peter R. Bream, Jr., MD
Associate Professor
Departments of Radiology and Radiological Sciences and Medicine
Vanderbilt University School of Medicine
Director, PICC Service
Program Director, Interventional and Vascular Radiology
Vanderbilt University Medical Center
Nashville, Tennessee
Tunneled Central Venous Catheters
Rachel F. Brem, MD
Professor
Department of Radiology
George Washington University School of Medicine and Health Sciences
Director
Breast Imaging and Interventional Center
Vice Chair of Radiology
GW Medical Faculty Associates
Washington, DC
Minimally Invasive Image-Guided Breast Biopsy and Ablation
Mark F. Brodie, MD
Interventional Radiologist
Department of Radiology
Naval Medical Center
San Diego, California
Fallopian Tube Interventions
Allan L. Brook, MD
Associate Professor of Clinical Radiology and Neurosurgery
Departments of Radiology and Surgery
Albert Einstein College of Medicine
Bronx, New York
DirectorInterventional Neuroradiology
Department of Radiology
Montefiore Medical Center
Brooklyn, New York
Management of Head and Neck Tumors
Benjamin S. Brooke, MD, PhD
Fellow
Vascular Surgery
Department of Surgery
Dartmouth-Hitchcock Medical Center
Lebanon, New Hampshire
Clinical Vascular Examination
Mark Duncan Brooks, MBBS, FRANZCR
Consultant Radiologist
Department of Radiology
Austin Hospital
Melbourne, Victoria, Australia
Transjugular Intrahepatic Portosystemic Shunts
Daniel B. Brown, MD
Director
Interventional Radiology
Department of Radiology
Thomas Jefferson University
Philadelphia, Pennsylvania
Management of Biliary Calculi
Karen T. Brown, MD, FSIR
Interventional Radiologist
Department of Medical Imaging
Memorial Sloan-Kettering Cancer Center
Professor of Clinical Radiology
Department of Radiology
Weill Cornell Medical College
New York, New York
Bland Embolization for Hepatic Malignancies
Jozef M. Brozyna, BS
West Virginia School of Osteopathic Medicine
Lewisburg, West Virginia
A Brief History of Image-Guided Therapy
Charles T. Burke, MD
Associate ProfessorDepartment of Radiology
University of North Carolina School of Medicine
Chapel Hill, North Carolina
Management of Failing Hemodialysis Access
Hemodialysis Access: Catheters and Ports
James P. Burnes, MBBS, FRACR
Director
Body Intervention Unit
Department of Diagnostic Imaging
Monash Medical Centre Moorabbin
Southern Health
Clayton, Victoria, Australia
Endovascular Treatment of Peripheral Aneurysms
Patricia E. Burrows, MD
Professor of Radiology
Medical College of Wisconsin
Vascular Interventional Radiology
Children's Hospital of Wisconsin
Milwaukee, Wisconsin
Management of Low-Flow Vascular Malformations
Justin J. Campbell, MD
Staff Radiologist
Department of Radiology
South Shore Hospital
Weymouth, Massachusetts
Percutaneous Abscess Drainage Within the Abdomen and Pelvis
Renal and Perirenal Fluid Collection Drainage
Colin P. Cantwell, MBBCh, BAO, Msc, MRCS, FRCR, FFR(RCSI)
Consultant Radiologist
Department of Radiology
St. Vincent's University Hospital
Dublin, Ireland
Peripherally Inserted Central Catheters and Nontunneled Central Venous Catheters
Thierry Carrères, MD
Cardio-vasculaire Radiologie
Hopital Européen Georges Pompidou
Paris, France
Infrapopliteal Revascularization
John A. Carrino, MD, MPH
Associate Professor of Radiology and Orthopedic SurgerySection Chief, Musculoskeletal Radiology
The Russell H. Morgan Department of Radiology and Radiological Science
Johns Hopkins University
School of Medicine
Baltimore, Maryland
Image-Guided Percutaneous Biopsy of Musculoskeletal Lesions
Lucie Cassagnes, MD
Department of Radiology
University Hospital
Clemont-Ferrand, France
Acute Mesenteric Ischemia
Pascal Chabrot, MD, PhD
Faculty of Medicine
ISIT, UMR CNRS 6284 University D’Auvergne
Department of Radiology
University Hospital
Clermont-Ferrand, France
Acute Mesenteric Ischemia
Suma K. Chandra, MD
George Washington University Medical Center
Washington, DC
A Brief History of Image-Guided Therapy
Richard Chang, MD
Chief, Endocrine and Venous Services Section
Senior Clinician
Section of Interventional Radiology
National Institutes of Health
Bethesda, Maryland
Arteriography and Arterial Stimulation with Venous Sampling for Localizing Pancreatic
Endocrine Tumors
Rishabh Chaudhari, BA
Medical Student
George Washington University School of Medicine and Health Sciences
Washington, DC
Renal Vasculature
Lakhmir S. Chawla, MD
Associate Professor
Department of Medicine
George Washington University Medical Center
Washington, DCTreatment of Medical Emergencies
Hank K. Chen, MD
Section of Interventional Radiology
Department of Radiology
George Washington University Medical Center
Washington, DC
A Brief History of Image-Guided Therapy
Yung-Hsin Chen, MD
Assistant Clinical Professor of Radiology
Tufts University School of Medicine
Boston, Massachusetts
Image-Guided Percutaneous Biopsy of Musculoskeletal Lesions
Rush H. Chewning, MD
Chief Resident
Department of Radiology
University of Washington School of Medicine
Seattle, Washington
Endovascular Management of Epistaxis
Subarachnoid Hemorrhage
Albert K. Chun, MD
Assistant Professor of Radiology and Surgery
Division of Angiography and Interventional Radiology
George Washington University School of Medicine and Health Sciences
Washington, DC
Principles of Arterial Access
Joo-Young Chun, MMBS, BSc, MSc, MRCS, FBCR
Interventional Radiology Fellow
Department of Radiology
St. George's Hospital
London, United Kingdom
Aortic Endografting
Timothy W.I. Clark, MD, MSc, FRCP(C), FSIR
Associate Professor of Clinical Radiology
Department of Radiology
University of Pennsylvania School of Medicine
Philadelphia, Pennsylvania
Acute Upper Extremity Deep Venous Thrombosis
Management of Fluid Collections in Acute Pancreatitis
Chemical and Thermal Ablation of Desmoid Tumors
Wendy A. Cohen, MDProfessor of Radiology
University of Washington School of Medicine
Chief of Service
Department of Radiology
Harborview Medical Center
Seattle, Washington
Use of Skull Views in Visualization of Cerebral Vascular Anatomy
Bairbre Connolly, MB, FRCP(C)
Pediatric Interventional Radiologist
Department of Diagnostic Imaging
Hospital for Sick Children
Associate Professor
Medical Imaging Department
Earl Glenwood Coulson Chair
University of Toronto
Faculty of Medicine
Toronto, Ontario, Canada
Pediatric Gastrostomy and Gastrojejunostomy
Alison Corr, MBBCh, BSc
Faculty of Radiologists
Royal College of Surgeons
Dublin, Ireland
Percutaneous Biopsy of the Lung, Mediastinum, and Pleura
Anne M. Covey, MD, FSIR
Associate Professor of Radiology
Department of Diagnostic Radiology
Memorial Sloan-Kettering Cancer Center
New York, New York
Management of Malignant Biliary Tract Obstruction
Laura Crocetti, MD, PhD
Assistant Professor of Radiology
Department of Oncology, Transplants, and Advanced Technologies in Medicine
University of Pisa Faculty of Medicine
Pisa, Italy
Energy-Based Ablation of Hepatocellular Cancer
Charles D. Crum, MD
Neuroradiology Fellow
Department of Radiology
St. Joseph's Hospital and Medical Center
Phoenix, ArizonaCryoablation of Liver Tumors
T. Andrew Currier, BSEE, LLB, P ENG
Barrister and Solicitor
Perry and Currier
Patent and Trademark Agents
Toronto, Ontario, Canada
Intellectual Property Management
Ferenc Czeyda-Pommersheim, MD
Resident in Radiology
Mallinckrodt Institute of Radiology
Washington University
Saint Louis, Missouri
Uterine Fibroid Embolization
Michael D. Dake, MD
Professor of Cardiothoracic Surgery
Stanford University School of Medicine
Director
Catheterization Angiography Laboratory
Stanford University Medical Center
Stanford, California
Balloon Catheters
Endovascular Treatment of Dissection of the Aorta and Its Branches
Michael D. Darcy, MD
Professor of Radiology
Washington University St. Louis
Chief of Intereventional Radiology
Mallinckrodt Institute of Radiology
Saint Louis, Missouri
Management of Lower Gastrointestinal Bleeding
Ambulatory Phlebectomy
Sean R. Dariushnia, MD
Assistant Professor of Radiology
Division of Interventional Radiology and Image-Guided Medicine
Emory School of Medicine
Atlanta, Georgia
Management of Extremity Vascular Trauma
Robert S.M. Davies, MBChB, MRCS, MMed, FRCS (England)
Senior Clinical Fellow
British Society of Endovascular Therapy
Leicester, United KingdomSubintimal Angioplasty
Thierry de Baère, MD
Chief
Department of Interventional Radiology
Institut Gustave Roussy
Villejuif, France
Portal Vein Embolization
Intraarterial Ports for Chemotherapy
L. Mark Dean, MD
Interventional Radiologist
Riverside Methodist Hospital
Columbus, Ohio
Selective Nerve Root Block
Sudhen B. Desai, MD
Interventional Radiologist
Methodist Sugar Land Hospital
Houston, Texas
Percutaneous Biopsy
Treatment of Effusions and Abscesses
Massimiliano di Primio, MD
Division of Interventional Radiology
Hopital Européen Georges Pompidou
Paris, France
Infrapopliteal Revascularization
Robert G. Dixon, MD
Associate Professor
Department of Radiology
University of North Carolina School of Medicine
Chapel Hill, North Carolina
Subcutaneous Ports
Pablo D. Domínguez, MD
Department of Radiology
Clínica Universitaria de Navarra
Pamplona, Spain
Portal-Mesenteric Venous Thrombosis
Robert F. Dondelinger, MD, Hon FRCR
Professor and Chair
Department of Medical Imaging
University of Liège Faculty of Medicine
Liège, BelgiumManagement of Trauma to the Liver and Spleen
Splenic Embolization in Nontraumatized Patients
Superior Vena Cava Occlusive Disease
Gregory J. Dubel, MD
Assistant Professor
Division of Vascular and Interventional Radiology
Warren Alpert Medical School
Brown University
Providence, Rhode Island
Stents
Damian E. Dupuy, MD, FACR
Professor
Department of Diagnostic Imaging
Warren Alpert Medical School
Brown University
Director of Tumor Ablation
Rhode Island Hospital
Providence, Rhode Island
Lung Ablation
Ghassan E. El-Haddad, MD
Assistant Member
Interventional Radiology
H. Lee Moffitt Cancer Center and Research Institute
Assistant Professor of Oncologic Sciences
University of South Florida
Tampa, Florida
Management of Renal Angiomyolipoma
Joseph P. Erinjeri, MD, PhD
Interventional Radiology Service
Memorial Sloan-Kettering Cancer Center
New York, New York
Chemical and Thermal Ablation of Desmoid Tumors
Clifford J. Eskey, MD
Assistant Professor
Department of Radiology
Dartmouth-Hitchcock Medical Center
Lebanon, New Hampshire
Vertebroplasty and Kyphoplasty
Thomas M. Fahrbach, MD
Radiology FellowDivision of Interventional Radiology and Image-Guided Medicine
Emory School of Medicine
Atlanta, Georgia
Percutaneous Cholecystostomy
Ronald M. Fairman, MD
Clyde F. Barker-William Maul Measey Professor
Surgery
University of Pennsylvania School of Medicine
Chief of Vascular Surgery and Endovascular Therapy
University of Pennsylvania Health System
Philadelphia, Pennsylvania
Thoracic Aortic Stent-Grafting and Management of Traumatic Thoracic Aortic Lesions
Chieh-Min Fan, MD
Associate Director
Division of Angiography and Interventional Radiology
Brigham and Women's Hospital
Assistant Professor
Department of Radiology
Harvard Medical School
Boston, Massachusetts
Thoracic Duct Embolization for Postoperative Chylothorax
Mark A. Farber, MD
Associate Professor
Departments of Radiology and Surgery
Director
Heart and Vascular Center
University of North Carolina School of Medicine
Chapel Hill, North Carolina
Aortic Stent-Grafts
Thoracic Aortic Stent-Grafting and Management of Traumatic Thoracic Aortic Lesions
Laura M. Fayad, MD
Associate Professor of Radiology, Orthopedic Surgery, and Oncology
The Russell H. Morgan Department of Radiology and Radiological Science
Johns Hopkins University
School of Medicine
Baltimore, Maryland
Image-Guided Percutaneous Biopsy of Musculoskeletal Lesions
Dimitrios Filippiadis, MD, PhD
Consultant
Attikon University HospitalAthens, Greece
Ablation and Combination Treatments of Bony Lesions
Sacroiliac Joint Injections
Kathleen R. Fink, MD
Assistant Professor of Neuroradiology
University of Washington School of Medicine
Seattle, Washington
Use of Skull Views in Visualization of Cerebral Vascular Anatomy
Sebastian Flacke, MD, PhD
Chief Interventional Radiology
Director of Non-Invasive Cardiovascular Imaging
Vice Chair, Department of Radiology
Lahey Clinic
Burlington, Massachusetts
Professor of Radiology
Tufts University Medical School
Boston, Massachusetts
Diagnostic Catheters and Guidewires
Karen Flood, BMedSci, BMBS, MMedSciClinEd, MRCS, FRCR
Interventional Radiology Registrar
Department of Vascular Interventional Radiology
Leeds Teaching Hospitals NHS Trust
Leeds, United Kingdom
Principles of Venous Access
Matthew D. Forrester, MD
Resident
Department of Cardiothoracic Surgery
Stanford University School of Medicine
Stanford, California
Endovascular Treatment of Dissection of the Aorta and Its Branches
Brian Funaki, MD
Professor
Department of Radiology
University of Chicago Pritzker School of Medicine
Section Chief
Division of Vascular and Interventional Radiology
University of Chicago Medical Center
Chicago, Illinois
Thombectomy Devices
Dimitri A. Gagarin, MDAssociate Professor of Medicine
Department of Internal Medicine
Virginia Commonwealth University
Richmond, Virginia
A Brief History of Image-Guided Therapy
Philippe Gailloud, MD
Director
Division of Interventional Neuroradiology
Johns Hopkins Hospital
Baltimore, Maryland
Craniocervical Vascular Anatomy
Arterial Anatomy of the Spine and Spinal Cord
Endovascular Management of Epistaxis
Bhaskar Ganai, BSc(MedSci) Hons, MBChB, MRCS, FRCR
SpR in Radiology
Department of Interventional Radiology
Freeman Hospital
Newcastle upon Tyne, United Kingdom
Embolic Protection Devices
Debra A. Gervais, MD
Associate Professor
Department of Radiology
Harvard Medical School
Division Head
Abdominal Imaging and Intervention
Massachusetts General Hospital
Boston, Massachusetts
Percutaneous Abscess Drainage Within the Abdomen and Pelvis
Renal and Perirenal Fluid Collection Drainage
Jean-François H. Geschwind, MD
Professor
Departments of Radiology, Surgery, and Oncology
Johns Hopkins University School of Medicine
Director
Interventional Radiology Center
Director
Vascular and Interventional Radiology
Johns Hopkins Medical Institutions
Baltimore, Maryland
Radioembolization for Hepatocellular CarcinomaBasavaraj V. Ghodke, MD
Associate Professor
Departments of Neuroradiology and Neurological Surgery
University of Washington School of Medicine
Director
Neuro-Interventional Radiology
Childrens Hospital and Research Center
Seattle, Washington
Use of Skull Views in Visualization of Cerebral Vascular Anatomy
Brian B. Ghoshhajra, MD, MBA
Director
Clinical Cardiac Imaging
Department of Radiology
Massachusetts General Hospital
Boston, Massachusetts
Noninvasive Vascular Diagnosis
Mark F. Given, MD, BCh, BAO, AFRCSI, FFRCR
Consultant
Radiologist
Beaumont Hospital
Dublin, Ireland
Anatomy of the Lower Limb
Acute Arterial Occlusive Disease of the Upper Extremity
Endovascular Treatment of Peripheral Aneurysms
Adrenal Venous Sampling
Parathyroid Venous Sampling
Percutaneous Biopsy of the Lung, Mediastinum, and Pleura
Y. Pierre Gobin, MD, MS
Professor of Radiology
Neurosurgery Department
Weill Cornell Medical College
New York, New York
Acute Stroke Management
Endovascular Management of Chronic Cerebral Ischemia
S. Nahum Goldberg, MD
Professor
Department of Radiology
Harvard Medical School
Beth Israel Deaconess Medical Center
Boston, MassachusettsVice Chair
Research Department of Radiology
Hadassah Hebrew University Medical Center
Hadassah, Israel
Image-Guided Thermal Tumor Ablation: Basic Science and Combination Therapies
Theodore S. Grabow, MD
Baltimore Spine Center and Maryland Pain Specialists
Adjunct Assistant Professor
Department of Anesthesiology and Critical Care Medicine
Johns Hopkins University School of Medicine
Baltimore, Maryland
Facet Joint Injection
Epidural Steroid Injection
Edward D. Greenberg, MD
Interventional Neuroradiology Fellow
Department of Radiology
Weill Cornell Medical College
New York-Presbyterian Hospital
New York, New York
Acute Stroke Management
Endovascular Management of Chronic Cerebral Ischemia
Bryan Grieme, MD
Medical Director
Interventional Radiology
St. Anthony Hospital
Oklahoma City, Oklahoma
Management of Male Varicocele
Gianluigi Guarnieri, MD
Neuroradiology Service
Cardarelli Hospital
Naples, Italy
Minimally Invasive Disk Interventions
Jeffrey P. Guenette, MD
Department of Diagnostic Imaging
Warren Alpert Medical School
Brown University
Providence, Rhode Island
Lung Ablation
Klaus D. Hagspiel, MD
ProfessorDepartments of Radiology, Medicine (Cardiology), and Pediatrics
Chief
Division of Noninvasive Cardiovascular Imaging
Department of Radiology and Medical Imaging
University of Virginia Health System
Charlottesville, Virginia
Balloon Catheters
Lee D. Hall, MD
Interventional Radiologist
Department of Radiology
Naval Medical Center
San Diego, California
Fallopian Tube Interventions
Danial K. Hallam, MD, MSc
Associate Professor
Departments of Radiology and Neurological Surgery
University of Washington School of Medicine
Seattle, Washington
Use of Skull Views in Visualization of Cerebral Vascular Anatomy
Mohomad Hamady, MBChB, FRCR
Consultant and Senior Lecturer
Department of Interventional Radiology
Imperial College
London, United Kingdom
Fenestrated Stent-Grafting of Juxtarenal Aortic Aneurysms
Stéphan Haulon, MD, PhD
Professor
Department of Vascular Surgery
Chief of Vascular Surgery
INSERM U1008, Université Lille Nord de France
Hôpital Cardiologique—CHRU
Lille, France
Management of Thoracoabdominal Aneurysms by Branched Endograft Technology
Klaus A. Hausegger, MD
Associate Professor and Head
Department of Radiology
Institute of Interventional and Diagnostic Radiology
Klagenfurt, Austria
Endoleaks: Classification, Diagnosis, and Treatment
Management of Biliary LeaksMarkus H. Heim, MD
Professor of Medicine
Department of Bioscience
University of Basel
Division of Gastroenterology and Hepatology
Department of Medicine
University Hospital Basel
Basel, Switzerland
Transjugular Liver Biopsy
Katharine Henderson, MS
Genetic Counselor
Yale School of Medicine
Co-Director
Yale HHT Center
New Haven, Connecticut
Pulmonary Arteriovenous Malformations: Diagnosis and Management
Robert C. Heng, MBBS, FRANZCR
Interventional Radiologist
Department of Radiology and Medical Imaging
Launceston General Hospital
Launceston, Tasmania, Australia
Vascular Anatomy of the Thorax, Including the Heart
Joshua A. Hirsch, MD
Associate Professor of Radiology
Harvard Medical School
Department of Radiology
Massachusetts General Hospital
Boston, Massachusetts
Vertebroplasty and Kyphoplasty
Andrew Hugh Holden, MBChB, FRANCZR
Associate Professor
Department of Radiology
Auckland University School of Medicine
Director
Body Imaging and Interventional Services
Auckland City Hospital
Auckland, New Zealand
Acute Renal Ischemia
Edward T. Horn, PharmD, BCPS
Clinical Pharmacy SpecialistDepartment of Pharmacy
Allegheny General Hospital
Pittsburgh, Pennsylvania
Vasoactive Agents
Joseph A. Hughes, MD
Fellow, Cardiovascular and Interventional Radiology
Department of Radiology
Pennsylvania State University College of Medicine
Penn State Hershey Medical Center
Hershey, Pennsylvania
Peripherally Inserted Central Catheters and Nontunneled Central Venous Catheters
Elizabeth A. Ignacio, MD
Associate Professor of Radiology
Division of Vascular and Interventional Radiology
George Washington University School of Medicine and Health Sciences
Washington, DC
Interventional Radiologist
Department of Radiology
Maui Memorial Medical Center
Wailuku, Hawaii
Vascular Anatomy of the Pelvis
Peripartum Hemorrhage
Zubin D. Irani, MD, MBBS
Instructor in Radiology
Harvard Medical School
Department of Medical Imaging
Massachusetts General Hospital
Boston, Massachusetts
Bronchial Artery Embolization
Roberto Izzo, MD, Neuroradiology Service
Carderelli Hospital
Naples, Italy
James E. Jackson, MBBS, FRCP, FRCR
Consultant Interventional Radiologist
Department of Imaging
Hammersmith Hospital
London, United Kingdom
Management of High-Flow Vascular Anomalies
Management of Visceral Aneurysms
Augustinus Ludwig Jacob, Prof MDProfessor
Department of Radiology
University of Basel
Head
Division of Interventional Radiology
Institute of Radiology
Basel, Switzerland
Transjugular Liver Biopsy
Abdel Aziz A. Jaffan, MD
Assistant Professor of Radiology
Division of Interventional Radiology and Image-Guided Medicine
Emory University School of Medicine
Atlanta, Georgia
Aortoiliac Revascularization
Priya Jagia, MD, DNB
Associate Professor
Department of Cardiac Radiology
All India Institute of Medical Sciences
New Delhi, India
Management of Vascular Arteritidies
Raagsudha Jhavar, MD
Special Volunteer
Urologic Oncology
National Cancer Institute
US National Institutes of Health
Bethesda, Maryland
Principles of Thrombolytic Agents
Francis Joffre, MD
Professeur
Service de Radiologie
L'Hôpital de Rangueil
Universitaire de Toulouse
Toulouse, France
Vascular Intervention in the Liver Transplant Patient
Matthew S. Johnson, MD
Professor
Departments of Radiology and Surgery
Indiana University School of Medicine
Indianapolis, Indiana
RestenosisAmber Jones, CCRP
Senior Research Program Coordinator
Fellowship Program Coordinator
Endovascular Surgical Neuroradiology
Division of Interventional Neuroradiology
Johns Hopkins University School of Medicine
Baltimore, Maryland
Vascular Anatomy of the Upper Extremity
Abdominal Aorta and the Inferior Vena Cava
Verena Kahn, MD
Department of Diagnostic and Interventional Radiology
University of Frankfurt am Main
Frankfurt, am Main, Germany
Endovascular Laser Therapy
Özlem Tuğçe Kalayci, MD
Department of Radiology
Inonu University Medical Faculty
Malayta, Turkey
Congenital Vascular Anomalies: Classification and Terminology
Sanjeeva Prasad Kalva, MD
Assistant Radiologist
Department of Imaging
Massachusetts General Hospital
Assistant Professor
Department of Radiology
Harvard Medical School
Boston, Massachusetts
Noninvasive Vascular Diagnosis
Anthony W. Kam, MD, PhD
Assistant Professor
Department of Radiology
Johns Hopkins Medical Institutions
Baltimore, Maryland
Arteriography and Arterial Stimulation with Venous Sampling for Localizing Pancreatic
Endocrine Tumors
Krishna Kandarpa, MD, PhD
Professor and Chair
Department of Radiology
University of Massachusetts School of Medicine
Adjunct ProfessorBiomedical Engineering
Worcester Polytechnic Institute
Radiologist-in-Chief
Department of Radiology
University of Massachusetts Memorial Health Care
Worcester, Massachusetts
Acute Lower Extremity Ischemia
Zinvoy M. Katz, MD
Clinical Instructor
Division of Interventional Neuroradiology
Johns Hopkins University School of Medicine
Baltimore, Maryland
Carotid Revascularization
John A. Kaufman, MD, MS
Director
Dotter Interventional Institute
Oregon Health and Science University
Portland, Oregon
Invasive Vascular Diagnosis
Superior Vena Cava Occlusive Disease
Linda Kelahan, MD
Department of Radiology
Washington Hospital Center
Washington, DC
Bipedal Lymphangiography
Alexis D. Kelekis, MD, PhD, EBIR
Assistant Professor of Interventional Radiology
Second Radiology Department
Attikon University Hospital
University of Athens
Athens, Greece
Ablation and Combination Treatments of Bony Lesions
Sacroiliac Joint Injections
Frederick S. Keller, MD
Cook Professor
Dotter Interventional Institute
Oregon Health and Sciences University
Portland, Oregon
Bronchial Artery Embolization
Robert K. Kerlan, Jr., MDProfessor of Clinical Radiology and Surgery
Department of Radiology
University of California–San Francisco
San Francisco, California
Biliary Complications Associated with Liver Transplantation
David O. Kessel, MBBS, MA, MRCP, FRCR, EBIR
Consultant Radiologist
Department of Vascular Interventional Radiology
Leeds Teaching Hospitals NHS Trust
Leeds, United Kingdom
Principles of Venous Access
Ramy Khalil, MS
Department of Radiology
George Washington University School of Medicine and Health Sciences
Washington, DC
Renal Vasculature
Nadia J. Khati, MD
Associate Professor of Radiology
Abdominal Imaging Section
George Washington University Medical Center
Washington, DC
Alimentary Tract Vasculature
Renal Vasculature
Vascular Anatomy of the Pelvis
Neil M. Khilnani, MD
Associate Professor of Clinical Radiology
Division of Vascular and Interventional Radiology
Weill Cornell Medical College
Division of Cardiovascular and Interventional Radiology
New York-Presbyterian Hospital
New York, New York
Great Saphenous Vein Ablation
Magnetic Resonance–Guided Focused Ultrasound Treatment of Uterine Leiomyomas
Darren D. Kies, MD
Assistant Professor of Radiology
Department of Radiology and Imaging Sciences
Emory School of Medicine
Atlanta, Georgia
Management of Female Venous Congestion Syndrome
Hyun S. Kim, MDAssociate Professor of Radiology, Obstetrics and Gynecology, Hematology and Medical
Oncology, and Surgery
Director
Interventional Radiology and Image-Guided Medicine
Department of Radiology and Imaging Sciences
Emory School of Medicine
Atlanta, Georgia
Management of Female Venous Congestion Syndrome
Percutaneous Cholecystostomy
Jin Hyoung Kim, MD, PhD
Assistant Professor
Department of Radiology
Asan Medical Center
University of Ulsan College of Medicine
Seoul, Republic of Korea
Intervention for Gastric Outlet and Duodenal Obstruction
Kyung Rae Kim, MD
Assistant Professor
Department of Radiology
University of North Carolina School of Medicine
Chapel Hill, North Carolina
Hemodialysis Access: Catheters and Ports
Hiro Kiyosue, MD
Associate Professor
Department of Radiology
Oita Medical University
Yufu, Oita, Japan
Retrograde Balloon Occlusion Variceal Ablation
Sebastian Kos, MD, EBIR
Chairman
Institute of Radiology and Nuclear Medicine
Lucerne, Switzerland
Transjugular Liver Biopsy
Jim Koukounaras, MBBS, FRANCZR
Interventional Radiologist
Department of Radiology
The Alfred Hospital
Melbourne, Victoria, Australia
Adrenal Venous Sampling
Andres Krauthamer, MDResident
Department of Diagnostic Radiology
George Washington University Medical Center
Washington, DC
Principles of Intraprocedural Analgesics and Sedatives
Vascular Anatomy of the Pelvis
Venkatesh Krishnasamy, MD
Interventional Radiology Fellow
Division of Vascular and Interventional Radiology
George Washington University School of Medicine and Health Sciences
Washington, DC
Vascular Anatomy of the Pelvis
William T. Kuo, MD
Associate Professor
Director, IR Fellowship Program
Division of Vascular and Interventional Radiology
Stanford University Medical Center
Stanford, California
Percutaneous Interventions for Acute Pulmonary Embolism
Max Kupershmidt, MBBS, FRANCZR, MMed (Radiology)
Director of Ultrasound
Barwon Medical Imaging
Geelong, Victoria, Australia
Treatment of High-Flow Priapism and Erectile Dysfunction
Vineel Kurli, MMBS
Vascular and Interventional Radiologist
Medical Diagnostic Imaging Group
Phoenix, Arizona
Acute Upper Extremity Deep Venous Thrombosis
Jeanne M. LaBerge, MD
Professor in Residence
Department of Radiology
University of California–San Francisco
San Francisco, California
Biliary Complications Associated with Liver Transplantation
Pierre-Yves Laffy, MD
Cardio-vasculaire Radiologie
Hopital Européen Georges Pompidou
Paris, France
Infrapopliteal RevascularizationLeo P. Lawler, MD, MBBS, BAO, FRCR
Assistant Professor of Radiology
The Russell H. Morgan Department of Radiology and Radiological Science
Johns Hopkins Medical Institutions
Baltimore, Maryland
Percutaneous Cholecystostomy
McKinley C. Lawson, MD, PhD
Resident
Diagnostic Radiology Department
University of Colorado–Denver
Anschutz Medical Center
Aurora, Colorado
Embolization Agents
Judy M. Lee, MD
Assistant Professor
Department of Obstetrics and Gynecology
Johns Hopkins University School of Medicine
Baltimore, Maryland
Management of Female Venous Congestion Syndrome
Michael J. Lee, M.Sc, FRCPI, FRCR, FFR(RCSI), FSIR, EBIR
Professor of Radiology
Consultant Interventional Radiologist
Beaumont Hospital
Professor of Radiology
Royal College of Surgeons in Ireland
Department of Radiology
Dublin, Ireland
Gastrostomy and Gastrojejunostomy
Thomas Lemettre, MD
Radiologue
Clinique Claude Bernard
Albi, France
Vascular Intervention in the Liver Transplant Patient
Riccardo Lencioni, MD, PhD
Associate Professor
Department of Radiology
University of Pisa Faculty of Medicine
DirectorDivision of Diagnostic Imaging and Intervention
Department of Hepatology and Liver Transplantation
Pisa University Hospital
Pisa, Italy
Energy-Based Ablation of Hepatocellular Cancer
Robert J. Lewandowski, MD
Associate Professor
Department of Radiology
Feinberg School of Medicine
Chicago, Illinois
Radioembolization of Liver Metastases
Percutaneous Biopsy
Treatment of Effusions and Abscesses
John J. Lewin, III, PharmD, MBA, BCPS
Division Director
Critical Care and Surgery
Department of Pharmacy
Johns Hopkins Hospital
Adjunct Assistant Professor
Department of Anesthesiology and Critical Care Medicine
Johns Hopkins University School of Medicine
Baltimore, Maryland
Vasoactive Agents
Curtis A. Lewis, MD, MBA, JD
Assistant Professor of Radiology
Division of Interventional Radiology and Image-Guided Medicine
Emory School of Medicine
Atlanta, Georgia
Management of Extremity Vascular Trauma
Changqing Li, MB
Interventional Radiologist
Department of Radiology
Beijing Ditan Hospital
Beijing, China
Transjugular Intrahepatic Portosystemic Shunts
Eleni A. Liapi, MD
Instructor
Interventional Radiology Department
Johns Hopkins Medical Institutions
Baltimore, MarylandRadioembolization for Hepatocellular Carcinoma
Yean L. Lim, MD, PhD
Professioral Fellow
Department of Cardiology
University of Melbourne Faculty of Medicine
Professor and Director
Centre for Cardiovascular Therapeutics
Western Health
Melbourne, Victoria, Australia
Director
Raffles Heart Hospital
Changhi, Singapore
Permanent Secretary
Asian Pacific Society of Interventional Cardiology
Wanchai, Hong Kong
Vascular Anatomy of the Thorax, Including the Heart
Raymond W. Liu, MD
Assistant Radiologist
Division of Vascular Imaging and Intervention
Massachusetts General Hospital
Boston, Massachusetts
Acute Lower Extremity Ischemia
Rafael H. Llinas, MD
Associate Professor
Department of Neurology
Johns Hopkins University School of Medicine
Clinical Vice Chair of Neurology
Johns Hopkins Hospital
Baltimore, Maryland
Cerebral Functional Anatomy and Rapid Neurological Examination
Reinhard Loose, MD, PhD
Department of Diagnostic and Interventional Radiology
Klinikum Nürmberg-Nord
Nürmberg, Bavaria, Germany
Angioplasty
Stuart M. Lyon, MBBS, FRNZCR
Adjunct Clinical Associate Professor
Department of Surgery
Central Clinical School
Monash UniversityDirector of Interventional Radiology
Alfred Hospital
Melbourne, Victoria, Australia
Acute Arterial Occlusive Disease of the Upper Extremity
Endovascular Treatment of Peripheral Aneurysms
Percutaneous Biopsy of the Lung, Mediastinum, and Pleura
Sumaira Macdonald, MBChB, FRCR, PhD, EBIR
Consultant
Vascular Radiologist
Department of Interventional Radiology
Freeman Hospital
Newcastle upon Tyne
United Kingdom
Embolic Protection Devices
Patrick C. Malloy, MD
Chairman
Department of Radiology
VA New York Harbor Healthcare System
New York, New York
Management of Pelvic Hemorrhage in Trauma
Mark D. Mamlouk, MD
Department of Radiological Sciences
University of California–Irvine
Orange, California
Cryoablation of Liver Tumors
Michael J. Manzano, MD
Radiologist
Private Practice
Pittsford, New York
Alimentary Tract Vasculature
Marie Agnès Marachet, MD
Praticien Hospitalier
Service de Radiologie
L'Hôpital de Rangueil
Universitaire de Toulouse
Toulouse, France
Vascular Intervention in the Liver Transplant Patient
Jean-Baptiste Martin, MD
Associate Radiologist
Radiology DepartmentGeneva University Hospital
Geneva, Switzerland
Ablation and Combination Treatments of Bony Lesions
Antonio Martínez-Cuesta, MD, MSc, FRCR
Department of Radiology
Hospital de Navarra
Pamplona, Spain
Portal-Mesenteric Venous Thrombosis
M. Victoria Marx, MD
Professor of Clinical Radiology
Radiology Keck School of Medicine
University of Southern California
Los Angeles, California
Radiation Safety and Protection in the Interventional Fluoroscopy Environment
Surena F. Matin, MD
Associate Professor
Department of Urology
University of Texas
MD Anderson Cancer Center
Houston, Texas
Thermal Ablation of Renal Cell Carcinoma
Alan H. Matsumoto, MD, FSIR, FACR, FAHA
Professor and Chair
Department of Radiology
University of Virginia School of Medicine
Division of Interventional Radiology, Angiography, and Special Procedures
Department of Radiology and Medical Imaging
University of Virginia Health System
Charlottesville, Virginia
Balloon Catheters
Closure Devices
Chronic Mesenetric Ischemia
Tracheobronchial Interventions
Matthew A. Mauro, MD, FACR
The Ernest H. Wood Distinguished Professor of Radiology and Surgery
Chairman, Department of Radiology
University of North Carolina School of Medicine
Chapel Hill, North Carolina
Percutaneous Management of Chronic Lower Extremity Venous Occlusive DiseaseGordon McLennan, MD, FISR
Department of Diagnostic Radiology
Cleveland Clinic Foundation
Cleveland, Ohio
Restenosis
Simon J. McPherson, MRCP, FRCR
Consultant
Vascular and Interventional Radiologist
Department of Radiology
Leeds General Infirmary
Leeds, United Kingdom
Management of Upper Gastrointestinal Hemorrhage
Khairuddin Memon, MD
Clinical Research Associate
Department of Radiology
Feinberg School of Medicine
Chicago, Illinois
Radioembolization of Liver Metastases
Steven G. Meranze, MD
Professor of Radiology and Surgery
Vice-Chair
Department of Radiology and Radiological Science
Vanderbilt University School of Medicine
Nashville, Tennessee
Percutaneous Nephrostomy, Cystostomy, and Nephroureteral Stenting
Todd S. Miller, MD
Faculty
Department of Interventional Neuroradiology
Montefiore Medical Center
Assistant Professor of Clinical Radiology
Department of Radiology
Albert Einstein College of Medicine
Bronx, New York
Management of Head and Neck Tumors
Robert J. Min, MD, MBA
Chairman of Radiology
Weill Cornell Medical College
Radiologist-in-Chief
New York-Presbyterian Hospital
New York, New YorkGreat Saphenous Vein Ablation
Sally E. Mitchell, MD, FISR, FCIRSE
Professor of Radiology, Surgery, and Pediatrics
Division of Interventional Radiology
Johns Hopkins Hospital
Baltimore, Maryland
Congenital Vascular Anomalies: Classification and Terminology
Urodynamics
Stephan Moll, MD
Associate Professor
Department of Medicine
Division of Hematology-Oncology
University of North Carolina School of Medicine
Chapel Hill, North Carolina
Antiplatelet Agents and Anticoagulants
Robert A. Morgan, MBChB, MRCP, FRCR, EBIR
Consultant, Vascular and Interventional Radiologist
Radiology Department
St George's NHS Trust
London, United Kingdom
Aortic Endografting
Hiromu Mori, MD
Professor and Chairperson
Department of Radiology
Oita Medical University
Yufu, Oita, Japan
Retrograde Balloon Occlusion Variceal Ablation
Paul R. Morrison, MS
Medical Physicist
Department of Radiology
Harvard Medical School
Brigham and Women's Hospital
Boston, Massachusetts
Cryoablation of Liver Tumors
Stefan Müller-Hülsbeck, MD, EBIR, FCIRSE, FICA
Professor of Radiology
Head
Department of Diagnostic and Interventional Radiology/Neuroradiology
Ev.-Luth. Diakonissenanstalt zu Flensburg
Flensburg, GermanyAtherectomy Devices
Kieran P.J. Murphy, MB, FRCPC, FSIR
Professor of Radiology
Joint Department of Medical Imaging
University Health Network
Mount Sinai Hospital
Women's College Hospital
Toronto, Ontario, Canada
Endovascular Management of Epistaxis
Subarachnoid Hemorrhage
Image-Guided Intervention for Symptomatic Tarlov Cysts
Scalene Blocks and Their Role in Thoracic Outlet Syndrome
Timothy P. Murphy, MD, FSIR, FAHA, FSVB, FACR
Professor
Department of Diagnostic Imaging
Warren Alpert Medical School
Brown University
Director
Vascular Disease Research Center
Department of Diagnostic Imaging
Rhode Island Hospital
Providence, Rhode Island
Stents
Aortoiliac Revascularization
Mario Muto, MD
Chair of Neuroradiology Service
Carderelli Hospital
Naples, Italy
Minimally Invasive Disk Interventions
Periradicular Therapy
Albert A. Nemcek, Jr., MD
Professor
Department of Radiology
Feinberg School of Medicine
Staff Interventional Radiologist
Northwestern Memorial Hospital
Chicago, Illinois
Percutaneous Biopsy
Treatment of Effusions and Abscesses
David B. Nicholson, C-RTRadiologic Technologist
Department of Radiology
University of Virginia School of Medicine
Charlottesville, Virginia
Balloon Catheters
Ali Noor, MD
Department of Radiology
Mount Sinai Medical Center
New York, New York
Renal Vasculature
Bipedal Lymphangiography
Philippe Otal, MD
Professeur
Service de Radiologie
L'Hôpital Rangueil
Universitaire de Toulouse
Toulouse, France
Vascular Intervention in the Liver Transplant Patient
Randall P. Owen, MD
Department of Otolaryngology-Head and Neck Surgery
Mount Sinai Medical Center
New York, New York
Management of Head and Neck Tumors
Auh Whan Park, MD
Associate Professor
Department of Radiology
University of Virginia Medical Center
Charlottesville, Virginia
Closure Devices
Tracheobronchial Interventions
David A. Pastel, MD
Assistant Professor
Department of Radiology
Dartmouth-Hitchcock Medical Center
Lebanon, New Hampshire
Vertebroplasty and Kyphoplasty
Aalpen A. Patel, MD
Vice Chair
Clinical Operations
System RadiologyGeisinger Health System
Danville, Pennsylvania
Management of Clotted Hemodialysis Access Grafts
Rafiuddin Patel, MBChB (Honours), MRCS, FRCR
SpR in Interventional Radiology
Department of Vascular Radiology
Leeds General Infirmary
Leeds, United Kingdom
Management of Upper Gastrointestinal Hemorrhage
Monica Smith Pearl, MD
Assistant Professor of Radiology
Division of Interventional Neuroradiology
Johns Hopkins Hospital
Baltimore, Maryland
Director of Pediatric Neurointervention
Department of Radiology
Children's National Medical Center
Washington, DC
Vascular Anatomy of the Upper Extremity
Abdominal Aorta and the Inferior Vena Cava
Olivier Pellerin, MD, MSc
Faculté de Médecine
Université Paris Descartes
Sorbonne Paris-Cité
Paris, France
Infrapopliteal Revascularization
Daniel D. Picus, MD
Professor
Departments of Radiology and Surgery
Washington University School of Medicine
Chief
Division of Diagnostic Radiology
Interventional Radiology Section
Mallinckrodt Institute of Radiology
Barnes-Jewish Hospital
Saint Louis, Missouri
Management of Biliary Calculi
João M. Pisco, MD
Professor and Chair
Department of RadiologyCentro Hospitalar Lisboa Norte EPE Hospital
Pulido Valente, Lisbon, Portugal
Treatment of High-Flow Priapism and Erectile Dysfunction
Jeffrey S. Pollak, MD
Professor of Radiology
Co-Section Chief
Division of Vascular and Interventional Radiology
Department of Diagnostic Radiology
Yale School of Medicine
New Haven, Connecticut
Pulmonary Arteriovenous Malformations: Diagnosis and Management
Rupert H. Portugaller, MD
Associate Professor
Department of Vascular and Interventional Radiology
University Clinic of Radiology
Medical University Graz
Graz, Austria
Management of Biliary Leaks
Sarah Power, MD
Resident
Department of Radiology
Beaumont Hospital
Dublin, Ireland
Gastrostomy and Gastrojejunostomy
Denis Primakov, MD
Interventional Radiologist
Walter Reed National Military Medical Center
Assistant Professor of Radiology and Radiological Sciences
Uniformed Services University of the Health Sciences
Bethesda, Maryland
Bipedal Lymphangiography
David S. Pryluck, MD
Fellow
Vascular and Interventional Radiology
Department of Radiology
University of Pennsylvania School of Medicine
Philadelphia, Pennsylvania
Acute Upper Extremity Deep Venous Thrombosis
Management of Fluid Collections in Acute Pancreatitis
Chemical and Thermal Ablation of Desmoid TumorsMartin G. Radvany, MD
Assistant Professor of Radiology, Neurological Surgery, and Neurology
Division of Interventional Neuroradiology
Johns Hopkins University School of Medicine
Baltimore, Maryland
Carotid Revascularization
Batya R. Radzik, MSN, CRNP, BC
Nurse Practitioner
Neurocritical Care
Department of Anesthesia and Critical Care Medicine
Johns Hopkins Hospital
Baltimore, Maryland
Cerebral Functional Anatomy and Rapid Neurological Examination
Suman Rathbun, MD, MS, RVT
Professor
Department of Medicine
University of Oklahoma Health Sciences Center
Oklahoma City, Oklahoma
Management of Risk Factors for Peripheral Artery Disease
Anne Ravel, MD
Faculty of Medicine
University Hospital
Clermont-Ferrand, France
Acute Mesenteric Ischemia
Charles E. Ray, Jr., MD, PhD
Professor and Vice-Chair of Research
Department of Radiology
Chief
Division of Interventional Radiology
University of Colorado–Denver
Anschutz Medical Center
Aurora, Colorado
Embolization Agents
Mahmood K. Razavi, MD
Director
Center for Clinical Trials and Research
Heart and Vascular Center
St. Joseph Hospital
Orange, California
Endovascular Management of Chronic Femoropopliteal DiseaseAaron Reposar
Medical Student
George Washington University School of Medicine and Health Sciences
Washington, DC
Renal Vasculature
Anne Roberts, MD
Professor
Department of Radiology
University of California–San Diego
Chief, Vascular and Interventional Radiology
UCSD Medical Center
Department of Radiology
VA Medical Center
San Diego, California
Surveillance of Hemodialysis Access
Alain Roche, MD
Professor and Chief
Department of Medical Imaging
Institut Gustave Roussy
Villejuif, France
Director
Laboratory UPRES EA 4040
Department of Interventional Radiology
University of Paris South
Paris, France
Portal Vein Embolization
Hervé Rousseau, MD
Professeur et Chef de service
Service de Radiologie L'Hôpital
Rangueil Universitaire de Toulouse
Toulouse, France
Vascular Intervention in the Liver Transplant Patient
Stefan G. Ruehm, MD, PhD
Professor
Department of Radiological Sciences
David Geffen School of Medicine at UCLA
University of California–Los Angeles
Director
Cardiovascular Imaging
Santa Monica-UCLA Medical Center and Orthopedic HospitalLos Angeles, California
Clinical Manifestations of Lymphatic Disease
Diego San, Millán Ruiz, MD
Neuroradiologist
Department of Diagnostic and Interventional Radiology
Hospital of Sion
Sion, Switzerland
Craniocervical Vascular Anatomy
John H. Rundback, MD, FAHA, FSVM, FSIR
Medical Director
Interventional Institute
Holy Name Medical Center
Teaneck, New Jersey
Renovascular Intervention
Chemical Ablation of Liver Lesions
Wael E.A. Saad, MD, FSIR
Associate Professor of Radiology
Division of Angiography and Interventional Radiology
University of Virginia School of Medicine
Charlottesville, Virginia
Balloon Catheters
Management of Postcatheterization Pseudoaneurysms
Management of Benign Biliary Strictures
Tarun Sabharwal, MBChB, FRCSI, FRCR
Consultant
Interventional Radiologist and Honorary Senior Lecturer
Department of Radiology
Guy's and St. Thomas' Hospital
London, United Kingdom
Esophageal Intervention in Malignant and Benign Esophageal Disease
Riad Salem, MD, MBA
Professor
Departments of Radiology, Medicine (Hematology-Oncology), and Surgery
Feinberg School of Medicine
Director
Interventional Oncology
Robert H. Lurie Comprehensive Cancer Center
Northwestern Memorial Hospital
Chicago, Illinois
Radioembolization of Liver MetastasesMarc Sapoval, MD, PhD
Head
Division of Interventional Radiology
Hopital Européen Georges Pompidou
Paris, France
Infrapopliteal Revascularization
Shawn N. Sarin, MD
Assistant Professor
Departments of Radiology and Surgery
Section of Vascular and Interventional Radiology
George Washington University Medical Center
Washington, DC
Balloon Catheters
Angioplasty
Matthew P. Schenker, MD
Associate Radiologist
Division of Angiography and Interventional Radiology
Brigham and Women's Hospital
Boston, Massachusetts
Thoracic Duct Embolization for Postoperative Chylothorax
Marc H. Schiffman, MD
Assistant Professor of Radiology
Division of Interventional Radiology
New York Hospital
Weill Cornell Medical College
New York, New York
Magnetic Resonance–Guided Focused Ultrasound Treatment of Uterine Leiomyomas
Sanjiv Sharma, MD
Professor
Department of Cardiac Radiology
All India Institute of Medical Sciences
New Delhi, India
Management of Vascular Arteritidies
Ji Hoon Shin, MD, PhD
Associate Professor
Department of Radiology
University of Ulsan College of Medicine
Research Institute of Radiology
Asan Medical Center
Seoul, KoreaTracheobronchial Interventions
H. Omur Sildiroglu, MD
Department of Radiology and Medical Imaging
University of Virginia Health System
Charlottesville, Virginia
Chronic Mesenteric Ischemia
Naomi N. Silva, MD
Resident
Department of Radiology
Robert Wood Johnson
University Hospital
New Brunswick, New York
Vascular Anatomy of the Pelvis
Stuart G. Silverman, MD
Professor
Department of Radiology
Harvard Medical School
Director of Abdominal Imaging and Intervention
Brigham and Women's Hospital
Boston, Massachusetts
Cryoablation of Liver Tumors
Charan K. Singh, MMBS
Assistant Professor of Radiology
Department of Diagnostic Imaging and Therapeutics
University of Connecticut School of Medicine
Farmingham, Connecticut
Acute Upper Extremity Deep Venous Thrombosis
Management of Fluid Collections in Acute Pancreatitis
Tony P. Smith, MD
Professor
Department of Radiology
Duke University School of Medicine
Division Chief
Peripheral and Neurological Interventional Radiology
Department of Radiology
Duke University Medical Center
Durham, North Carolina
Antibiotic Prophylaxis in Interventional Radiology
Constantinos T. Sofocleous, MD, PhD, FSIR
Interventional RadiologistDepartment of Radiology
Memorial Sloan-Kettering Cancer Center
New York, New York
Embolotherapy for the Management of Liver Malignancies Other Than Hepatocellular
Carcinoma
Luigi Solbiati, MD
University of Milan
Postgraduate Medical School
Milan, Italy
Department of Radiology and Interventional Radiology
Busto Arsizio General Hospital
Busto Arsizio, Italy
Energy-Based Ablation of Other Liver Lesions
Stephen B. Solomon, MD
Chief
Interventional Radiology
Service Director
Center for Image-Guided Intervention
Memorial Sloan-Kettering Cancer Center
New York, New York
Magnetic Resonance–Guided Focused Ultrasound Treatment of Uterine Leiomyomas
Ho-Young Song, MD, PhD
Professor
Department of Radiology
Asan Medical Center
University of Ulsan College of Medicine
Seoul, Republic of Korea
Intervention for Gastric Outlet and Duodenal Obstruction
Kean H. Soon, MMBS, PhD, FRACP, FCSANZ
Interventional Cardiologist
Centre for Cardiovascular Therapeutics
Western Hospital
Melbourne, Victoria, Australia
Vascular Anatomy of the Thorax, Including the Heart
David R. Sopko, MD
Associate
Department of Radiology
Duke University School of Medicine
Durham, North Carolina
Antibiotic Prophylaxis in Interventional RadiologyThomas A. Sos, MD
Professor
Department of Radiology
Weill Cornell Medical College
New York-Presbyterian Hospital
New York, New York
Renal Vein Renin Sampling
Michael C. Soulen, MD, FSIR, FCIRSE
Professor of Radiology
Department of Interventional Radiology
University of Pennsylvania School of Medicine
Philadelphia, Pennsylvania
Chemoembolization for Hepatocellular Carcinoma
James B. Spies, MD, MPH
Professor and Chair
Department of Radiology
Georgetown University Hospital
Washington, DC
Uterine Fibroid Embolization
Stavros Spiliopoulos, MD, PhD, EBIR
Board Certified Interventional Radiologist
Department of Interventional Radiology
Patras University Hospital
Rion, Greece
Esophageal Intervention in Malignant and Benign Esophageal Disease
M.J. Bernadette Stallmeyer, MD, PhD
Director
Division of Interventional Neuroradiology
Reading Hospital and Medical Center
West Reading, Pennsylvania
Management of Head and Neck Injuries
Joseph M. Stavas, MD
Professor
Department of Radiology
University of North Carolina School of Medicine
Chapel Hill, North Carolina
Biopsy Devices
LeAnn S. Stokes, MD
Assistant Professor
Department of Radiology and Radiological SciencesVanderbilt University Medical Center
Nashville, Tennessee
Percutaneous Nephrostomy, Cystostomy, and Nephroureteral Stenting
Ernst-Peter Strecker, MD
Professor Emeritus
Consultant Physician
Department of Diagnostic and Interventional Radiology
Trudpert Klinikum Pforzheim
Pforzheim, Germany
Intraarterial Ports for Chemotherapy
Michael B. Streiff, MD
Associate Professor of Medicine
Department of Medicine (Hematology)
Johns Hopkins Medical Institutions
Baltimore, Maryland
Principles of Thrombolytic Agents
Deepak Sudheendra, MD
Assistant Professor of Clinical Radiology and Surgery
University of Pennsylvania School of Medicine
Division of Interventional Radiology
Hospital of the University of Pennsylvania
Philadelphia, Pennsylvania
Management of Renal Angiomyolipoma
Thermal Ablation of the Adrenal Gland
Paul V. Suhocki, MD
Associate Professor
Department of Radiology
Duke University Medical Center
Durham, North Carolina
Foreign Body Retrieval
Alfonso Tafur, MD, RPVI
Assistant Professor of Medicine
Department of Vascular Medicine
Oklahoma University Health and Science Center
Oklahoma City, Oklahoma
Management of Risk Factors for Peripheral Artery Disease
M. Reza Taheri, MD, PhD
Assistant Professor
Department of Radiology
George Washington University School of Medicine and Health SciencesWashington, DC
Use of Skull Views in Visualization of Cerebral Vascular Anatomy
Jeff Dai-Chee Tam, MBBS, FRANCZR
Fellow
Interventional Radiology
Department of Radiology
Alfred Hospital
Melbourne, Victoria, Australia
Anatomy of the Lower Limb
Acute Arterial Occlusive Disease of the Upper Extremity
Parathyroid Venous Sampling
Elizabeth R. Tang, MD
Resident
Department of Radiology
Boston University
Boston, Massachusetts
Management of Head and Neck Tumors
Emily M. Tanski, PA-C
Physicians Assistant
Division of Vascular and Interventional Radiology
George Washington University School of Medicine
Washington, DC
Vascular Anatomy of the Pelvis
Management of Male Varicocele
Kiang Hiong Tay, MBBS, FRCR, FAMS, FSIR
Head and Senior Consultant
Department of Diagnostic Radiology
Singapore General Hospital
Associate Professor of Radiology
Duke NUS Graduate Medical School
Yong Loo Lin School of Medicine
National University of Singapore
Chairman
Cardiovascular and Interventional Radiology Subsection
Singapore Radiological Society
Honorary Secretary
College of Radiologists
Singapore
Peripartum Hemorrhage
Aylin Tekes, MDAssistant Professor
Department of Radiology
Johns Hopkins University School of Medicine
Radiologist
Division of Pediatric Radiology
Johns Hopkins Hospital
Baltimore, Maryland
Congenital Vascular Anomalies: Classification and Terminology
Matthew M. Thompson, MD, FRCS
Professor of Vascular Surgery
St. George's Vascular Institute
St. George's Hospital
London, United Kingdom
Aortic Endografting
Kenneth R. Thomson, MD, FRANZCR
Adjunct Clinical Professor of Radiology
Department of Surgery
Central Clinical School
Monash University
Program Director
Department of Radiology and Nuclear Medicine
Alfred Hospital
Melbourne, Victoria, Australia
Anatomy of the Lower Limb
Acute Arterial Occlusive Disease of the Upper Extremity
Endovascular Treatment of Peripheral Aneurysms
Treatment of High-Flow Priapism and Erectile Dysfunction
Adrenal Venous Sampling
Parathyroid Venous Sampling
Percutaneous Biopsy of the Lung, Mediastinum, and Pleura
Raymond H. Thornton, MD
Vice Chair for Quality, Safety, and Performance Improvement
Department of Radiology
Division of Interventional Radiology
Memorial Sloan-Kettering Cancer Center
New York, New York
Management of Malignant Biliary Tract Obstruction
Emily J. Timmreck, RN, MSN, ACNP-BC
Nurse Practitioner
Division of Vascular and Interventional RadiologyGeorge Washington University School of Medicine
Washington, DC
Vascular Anatomy of the Pelvis
Management of Male Varicocele
Jessica Torrente, MD
Assistant Professor of Radiology
Division of Breast Imaging and Intervention
George Washington University School of Medicine and Health Sciences
Washington, DC
Minimally Invasive Image-Guided Breast Biopsy and Ablation
Gina D. Tran, MD
Resident
Department of Family and Community Medicine
University of Nevada School of Medicine
Las Vegas, Nevada
A Brief History of Image-Guided Therapy
Scott Trerotola, MD
Associate Chair and Chief
Division of Interventional Radiology
University of Pennsylvania Medical Center
Philadelphia, Pennsylvania
Management of Clotted Hemodialysis Access Grafts
David W. Trost, MD
Associate Professor of Clinical Radiology
Division of Vascular and Interventional Radiology
Weill Medical College of Cornell University
Associate Attending Radiologist
Department of Radiology
New York-Presbyterian Hospital
New York, New York
Acute Lower Extremity Ischemia
Renal Vein Renin Sampling
Kemal Tuncali, MD
Instructor in Radiology
Harvard Medical School
Brigham and Women's Hospital
Boston, Massachusetts
Cryoablation of Liver Tumors
Ulku C. Turba, MD
Associate Professor of RadiologyDivision of Interventional Radiology, Angiography, and Special Procedures
Rush University Medical Center
Chicago, Illinois
Balloon Catheters
Chronic Mesenteric Ischemia
Mark R. Tyrrell, PhD, FRCS
Consultant Vascular Surgeon
Department of Vascular Surgery
King's College Hospital
London, United Kingdom
Management of Thoracoabdominal Aneurysms by Branched Endograft Technology
Raghuveer Vallabhaneni, MD
Assistant Professor of Surgery
Division of Vascular Surgery
University of North Carolina School of Medicine
Chapel Hill, North Carolina
Aortic Stent-Grafts
Eric vanSonnenberg, MD
Visiting Professor of Medicine
David Geffen School of Medicine at UCLA
Chief Academic Officer
Chief of Interventional Radiology and Interventional Oncology
Kern/UCLA Medical Center
Bakersfield, California
Professor
Arizona State University
Tempe, Arizona
Cryoablation of Liver Tumors
Prasanna Vasudevan, MD
Chief Resident
Department of Diagnostic Radiology
George Washington University Medical Center
Washington, DC
Angioplasty
Anthony C. Venbrux, MD
Director, Cardiovascular and Interventional Radiology
George Washington University School of Medicine and Health Sciences
Washington, DC
A Brief History of Image-Guided Therapy
AngioplastyAlimentary Tract Vasculature
Renal Vasculature
Management of Male Varicocele
Management of Female Venous Congestion Syndrome
Bipedal Lymphangiography
Bogdan Vierasu, MD
Praticien Hospitalier
Service Radiologie
L'Hôpital de Rangueil
Universitaire de Toulouse
Toulouse, France
Vascular Intervention in the Liver Transplant Patient
Isabel Vivas, MD
Professor of Radiology
Universidad de Navarra
Consultant Radiologist
Clínica Universitaria de Navarra
Pamplona, Spain
Portal-Mesenteric Venous Thrombosis
Dierk Vorwerk, MD
Professor and Director
Department of Radiology
Klinikum Ingolstadt
Ingolstadt, Germany
Renal Artery Embolization
Percutaneous Management of Thrombosis in Native Hemodialysis Shunts
David L. Waldman, MD, PhD
Professor and Chair
Department of Imaging Sciences
University of Rochester
Strong Memorial Hospital and Highland Hospital
Rochester, New York
FF Thompson Hospital
Canadaigua, New York
Management of Postcatheterization Pseudoaneurysms
Michael J. Wallace, MD
Professor
Department of Diagnostic Radiology
Section Chief
Interventional RadiologyUniversity of Texas
MD Anderson Cancer Center
Houston, Texas
Thermal Ablation of Renal Cell Carcinoma
Eric M. Walser, MD
Professor and Interim Chair
Department of Radiology
University of Texas
Medical Branch
Galveston, Texas
Endovascular Management of Chronic Femoropopliteal Disease
Antony S. Walton, MD
Interventional Cardiologist
Alfred Hospital
Prahran, Victoria, Australia
Vascular Anatomy of the Thorax, Including the Heart
Thomas J. Ward, MD
Resident in Radiology
Department of Radiology
Mount Sinai School of Medicine
New York, New York
Chemical Ablation of Liver Lesions
Anthony F. Watkinson, BSc, MSc (Oxon), MMBS, FRCS, FRCR, EBIR
Honorary Professor of Radiology
Peninsula College of Medicine and Dentistry
Universities of Exeter and Plymouth
Consultant Radiologist
Royal Devon and Exeter Hospital
Exeter, United Kingdom
Transvenous Renal Biopsy
Peter N. Waybill, MD, FSIR
Professor of Radiology, Medicine, and Surgery
Chief, Division of Cardiovascular and Interventional Radiology
Department of Radiology
Pennsylvania State University College of Medicine
Penn State Hershey Medical CenterHershey, Pennsylvania
Peripherally Inserted Central Catheters and Nontunneled Central Venous Catheters
Joshua L. Weintraub, MD, FSIR
Executive Vice Chairman
Department of Radiology
Professor of Radiology and Surgery
Columbia University College of Physicians and Surgeons
New York Presbyterian Hospital
New York, New York
Renovascular Interventions
Chemical Ablation of Liver Lesions
Robert I. White, Jr., MD
Professor Emeritus and Senior Research Scientist
Founder and Former Director
Yale HHT Center
Yale School of Medicine
New Haven, Connecticut
Pulmonary Arteriovenous Malformations: Diagnosis and Management
Mark H. Wholey, MD
Director of Peripheral Vascular Interventions
Chairman
Pittsburgh Vascular Institute
University of Pittsburgh Medical Center
Shadyside Hospital
Pittsburgh, Pennsylvania
Carotid Revascularization
C. Jason Wilkins, BMBCh, MRCP, FRCR
Consultant
Department of Radiology
King's College Hospital
London, United Kingdom
Management of Thoracoabdominal Aneurysms by Branched Endograft Technology
Bradford D. Winters, MD, PhD
Associate Professor
Departments of Anesthesiology and Critical Care Medicine, Neurology and Surgery
Johns Hopkins University School of Medicine
Baltimore, Maryland
Vasoactive Agents
Robert Wityk, MD
Associate Professor of NeurologyJohns Hopkins University School of Medicine
Baltimore, Maryland
Cervical Artery Dissection
Edward Y. Woo, MD
Associate Professor
Department of Surgery
University of Pennsylvania School of Medicine
Vice-Chief and Program Director
Division of Vascular Surgery and Endovascular Therapy
Director
Vascular Laboratory
University of Pennsylvania Health System
Philadelphia, Pennsylvania
Thoracic Aortic Stent-Grafting and Management of Traumatic Thoracic Aortic Lesions
Bradford J. Wood, MD
Director, Center for Interventional Oncology
Chief, Section of Interventional Radiology
Senior Investigator
National Institutes of Health
Bethesda, Maryland
Arteriography and Arterial Stimulation with Venous Sampling for Localizing Pancreatic
Endocrine Tumors
Thermal Ablation of the Adrenal Gland
Gerald M. Wyse, MBBCh, BAO, MRCPI, FFRCSI
Consultant Neuroradiologist
Department of Radiology
Cork University Hospital
Wilton, Cork, Ireland
Endovascular Management of Epistaxis
Subarachnoid Hemorrhage
Percutaneous Cholecystostomy
Image-Guided Intervention for Symptomatic Tarlov Cysts
Albert J. Yoo, MD
Assistant Professor of Radiology
Harvard Medical School
Department of Radiology
Massachusetts General Hospital
Boston, Masachusetts
Vertebroplasty and Kyphoplasty
Chang Jin Yoon, MD, PhDAssociate Professor
College of Medicine
Seoul National University
Seoul, Republic of Korea
Intervention for Gastric Outlet and Duodenal Obstruction
Hyeon Yu, MD
Assistant Professor
Department of Radiology
University of North Carolina School of Medicine
Chapel Hill, North Carolina
Percutaneous Management of Chronic Lower Extremity Venous Occlusive Disease
Hemodialysis Access: Catheters and Ports
Steven Zangan, MD
Assistant Professor
Department of Radiology
University of Chicago Pritzker School of Medicine
Chicago, Illinois
Thombectomy Devices
Fabio Zeccolini, MD
Neuroradiology Service
Cardarelli Hospital
Naples, Italy
Minimally Invasive Disk Interventions
†Eberhard Zeitler, MD
Professor
Department of Diagnostic and Interventional Radiology
Friedrich-Alexander University
Erlangen-Nürmberg
Emeritus Director
Department of Diagnostic and Interventional Radiology
Klinikum Nürmberg-Nord
Nürmberg, Bavaria, Germany
Angioplasty
Dianbo Zhang, MD
Assistant Professor
Department of Radiology
State University of New York
SUNY Upstate Medical Center
Syracuse, New YorkRestenosis
Christoph L. Zollikofer, MD
Professor
Department of Radiology
Kantonsspital Baden
Baden, Switzerland
Preoperative and Palliative Colonic Stenting
† D e c e a s e d


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Preface
The second edition of Image-Guided Interventions builds on the success of the rst as
an international body of work that draws on the knowledge and experience of
distinguished contributors from around the world. We believe the rst edition
ful lled our intent of producing a practical, concise, well-illustrated textbook
representative of the state of the art of interventional practice across the globe.
Because modern-day textbooks are no longer needed for an exhaustive list of the
current literature, only critical references were included. The second edition is a
continuation of this goal. Its ve principal editors were selected for their expertise
and global representation. Four have returned for the second edition: Drs. Murphy,
Venbrux, and Mauro from North America and Dr. Thomson from the Asia-Oceania
region. We bid a fond farewell to Christoph Zollikofer (Europe), who has nally
entered a well-deserved retirement, and welcome Robert Morgan as our European
representative.
The second edition has been reduced to one volume. Several components of the
text are o ered only as an online resource; these include references and
supplementary material. All of the core material with accompanying high-quality
color illustrations are present in the traditional printed book form. The rst edition
received particular acclaim for its radiographic images, tables, charts, and color
anatomic illustrations. These have been maintained and enhanced. We have also
retained the basic organization of the text into two basic parts: vascular
interventions and nonvascular Interventions. Part 1, Vascular Interventions, includes
not only diagnosis and intervention of primary vascular disorders (arterial, venous,
and lymphatic) but also diseases in other organ systems in which procedures are
performed using the vascular system as a conduit for intervention. Part 2,
Nonvascular Interventions, covers procedures performed via direct image-guided
percutaneous access into the organ or site of interest. Part 1 again begins with core
principles including vascular diagnosis, the instruments of intervention, patient care,
and the principles of vascular intervention. The subsequent focus of Part 1 is on
primary vascular disorders, including arterial, venous, and lymphatic diseases,
followed by an anatomic-based discussion of a wide variety of entities in which the
vascular tree is used as a conduit for intervention. Part 2 begins with an updated
description of biopsy devices, followed by a similarly anatomic-based discussion of
image-guided procedures utilizing direct access, including biopsy, drainages,
=

stenting, ablation, injections, and augmentation. All chapters have been updated,
and more than a third of the authors are newly appointed and offer specific expertise
in the subject matter.
Image-Guided Interventions is designed to be read either primarily from cover to
cover, or selectively in preparation for a speci c procedure. We have maintained an
organizational structure that highlights indications and contraindications for
procedures at the outset. Materials required for procedures are clearly listed for easy
reference, as are “Key Points” that sum up each chapter. High-quality illustrations
and drawings are in abundance because they are typically worth the proverbial
thousand words.
We have received tremendous positive feedback from seasoned interventionalists
and trainees alike for the rst edition of Image-Guided Interventions. The editors and
Elsevier have strived in earnest to produce a sequel worthy of its namesake. Like its
predecessor, Image-Guided Interventions, Second Edition, will maintain its relevance
through constant Internet updating. It is a textbook created and designed not to
gather dust on a bookshelf, but to be present in o ces and procedural areas alike,
well worn from constant use through reading and referral.
Matthew A. Mauro, MD, FACR
Kieran P.J. Murphy, MB, FRCPC, FSIR
Kenneth R. Thomson, MD, FRANZCR
Anthony C. Venbrux, MD
Robert A. Morgan, MBChB, MRCP, FRCR, EBIRP A R T 1
Vascular Interventions
OUTLINE
Chapter 1: A Brief History of Image-Guided Therapy
Chapter 2: Noninvasive Vascular Diagnosis
Chapter 3: Invasive Vascular Diagnosis
Chapter 4: Diagnostic Catheters and Guidewires
Chapter 5: Balloon Catheters
Chapter 6: Stents
Chapter 7: Thrombectomy Devices
Chapter 8: Embolic Protection Devices
Chapter 9: Atherectomy Devices
Chapter 10: Embolization Agents
Chapter 11: Aortic Stent-Grafts
Chapter 12: Inferior Vena Cava Filters
Chapter 13: Endovascular Laser Therapy
Chapter 14: Intellectual Property Management
Chapter 15: Clinical Vascular Examination
Chapter 16: Treatment of Medical Emergencies
Chapter 17: Radiation Safety and Protection in the Interventional Fluoroscopy
Environment
Chapter 18: Management of Risk Factors for Peripheral Artery Disease
Chapter 19: Principles of Intraprocedural Analgesics and Sedatives
Chapter 20: Contrast Agents
Chapter 21: Principles of Thrombolytic Agents
Chapter 22: Antiplatelet Agents and Anticoagulants
Chapter 23: Vasoactive Agents
Chapter 24: Antibiotic Prophylaxis in Interventional Radiology
Chapter 25: Angioplasty
Chapter 26: Restenosis
Chapter 27: Principles of Arterial Access
Chapter 28: Closure Devices
Chapter 29: Principles of Venous AccessChapter 30: Vascular Anatomy of the Upper Extremity
Chapter 31: Anatomy of the Lower Limb
Chapter 32: Acute Arterial Occlusive Disease of the Upper Extremity
Chapter 33: Acute Lower Extremity Ischemia
Chapter 34: Chronic Upper Extremity Ischemia and Revascularization
Chapter 35: Aortoiliac Revascularization
Chapter 36: Endovascular Management of Chronic Femoropopliteal Disease
Chapter 37: Infrapopliteal Revascularization
Chapter 38: Subintimal Angioplasty
Chapter 39: Management of Extremity Vascular Trauma
Chapter 40: Management of Postcatheterization Pseudoaneurysms
Chapter 41: Endovascular Treatment of Peripheral Aneurysms
Chapter 42: Management of Vascular Arteritides
Chapter 43: Congenital Vascular Anomalies: Classification and Terminology
Chapter 44: Management of Low-Flow Vascular Malformations
Chapter 45: Management of High-Flow Vascular Anomalies
Chapter 46: Abdominal Aorta and the Inferior Vena Cava
Chapter 47: Aortic Endografting
Chapter 48: Fenestrated Stent-Grafting of Juxtarenal Aortic Aneurysms
Chapter 49: Management of Thoracoabdominal Aneurysms by Branched
Endograft Technology
Chapter 50: Endoleaks: Classification, Diagnosis, and Treatment
Chapter 51: Endovascular Treatment of Dissection of the Aorta and Its
Branches
Chapter 52: Alimentary Tract Vasculature
Chapter 53: Management of Upper Gastrointestinal Hemorrhage
Chapter 54: Management of Lower Gastrointestinal Bleeding
Chapter 55: Acute Mesenteric Ischemia
Chapter 56: Chronic Mesenteric Ischemia
Chapter 57: Renal Vasculature
Chapter 58: Renovascular Interventions
Chapter 59: Acute Renal Ischemia
Chapter 60: Renal Artery Embolization
Chapter 61: Management of Renal Angiomyolipoma
Chapter 62: Transvenous Renal Biopsy
Chapter 63: Transjugular Liver Biopsy
Chapter 64: Chemoembolization for Hepatocellular Carcinoma
Chapter 65: Radioembolization for Hepatocellular CarcinomaChapter 66: Embolotherapy for the Management of Liver Malignancies Other
Than Hepatocellular Carcinoma
Chapter 67: Radioembolization of Liver Metastases
Chapter 68: Bland Embolization for Hepatic Malignancies
Chapter 69: Portal Vein Embolization
Chapter 70: Vascular Intervention in the Liver Transplant Patient
Chapter 71: Management of Trauma to the Liver and Spleen
Chapter 72: Splenic Embolization in Nontraumatized Patients
Chapter 73: Management of Visceral Aneurysms
Chapter 74: Intraarterial Ports for Chemotherapy
Chapter 75: Vascular Anatomy of the Pelvis
Chapter 76: Uterine Fibroid Embolization
Chapter 77: Peripartum Hemorrhage
Chapter 78: Management of Pelvic Hemorrhage in Trauma
Chapter 79: Management of Male Varicocele
Chapter 80: Management of Female Venous Congestion Syndrome
Chapter 81: Treatment of High-Flow Priapism and Erectile Dysfunction
Chapter 82: Vascular Anatomy of the Thorax, Including the Heart
Chapter 83: Thoracic Aortic Stent-Grafting and Management of Traumatic
Thoracic Aortic Lesions
Chapter 84: Bronchial Artery Embolization
Chapter 85: Pulmonary Arteriovenous Malformations: Diagnosis and
Management
Chapter 86: Percutaneous Interventions for Acute Pulmonary Embolism
Chapter 87: Craniocervical Vascular Anatomy
Chapter 88: Arterial Anatomy of the Spine and Spinal Cord
Chapter 89: Use of Skull Views in Visualization of Cerebral Vascular Anatomy
Chapter 90: Cerebral Functional Anatomy and Rapid Neurologic Examination
Chapter 91: Carotid Revascularization
Chapter 92: Acute Stroke Management
Chapter 93: Endovascular Management of Chronic Cerebral Ischemia
Chapter 94: Management of Head and Neck Tumors
Chapter 95: Endovascular Management of Epistaxis
Chapter 96: Subarachnoid Hemorrhage
Chapter 97: Management of Head and Neck Injuries
Chapter 98: Cervical Artery Dissection
Chapter 99: Superior Vena Cava Occlusive Disease
Chapter 100: Percutaneous Management of Chronic Lower Extremity VenousOcclusive Disease
Chapter 101: Acute Lower Extremity Deep Venous Thrombosis
Chapter 102: Acute Upper Extremity Deep Venous Thrombosis
Chapter 103: Portal-Mesenteric Venous Thrombosis
Chapter 104: Caval Filtration
Chapter 105: Ambulatory Phlebectomy
Chapter 106: Great Saphenous Vein Ablation
Chapter 107: Foreign Body Retrieval
Chapter 108: Renal Vein Renin Sampling
Chapter 109: Adrenal Venous Sampling
Chapter 110: Parathyroid Venous Sampling
Chapter 111: Arteriography and Arterial Stimulation with Venous Sampling for
Localizing Pancreatic Endocrine Tumors
Chapter 112: Transjugular Intrahepatic Portosystemic Shunts
Chapter 113: Retrograde Balloon Occlusion Variceal Ablation
Chapter 114: Surveillance of Hemodialysis Access
Chapter 115: Management of Failing Hemodialysis Access
Chapter 116: Management of Clotted Hemodialysis Access Grafts
Chapter 117: Percutaneous Management of Thrombosis in Native Hemodialysis
Shunts
Chapter 118: Peripherally Inserted Central Catheters and Nontunneled Central
Venous Catheters
Chapter 119: Tunneled Central Venous Catheters
Chapter 120: Subcutaneous Ports
Chapter 121: Hemodialysis Access: Catheters and Ports
Chapter 122: Clinical Manifestations of Lymphatic Disease
Chapter 123: Bipedal Lymphangiography
Chapter 124: Thoracic Duct Embolization for Postoperative ChylothoraxS E C T I O N O N E
History of Angiography
and Intervention
OUTLINE
Chapter 1: A Brief History of Image-Guided TherapyC H A P T E R 1
A Brief History of Image-Guided
Therapy
Anthony C. Venbrux, Jozef M. Brozyna, Suma Chandra, Hank K. Chen, Gina D. Tran and Dmitri A.
Gagarin
Historical Highlights of Endovascular Therapy
• British dentist Charles Stent develops a plastic material for taking mouth impressions (i.e.,
creates a “scaffold”) (1856).
• Image guidance was made possible by the discovery of x-rays by Wilhelm Conrad Röntgen,
November 8, 1895 (Figs. 1-1 to 1-3).
FIGURE 1-1 Photograph of Roentgen taken in 1906 while he was director
of the Institute of Physics at the University of Munich. (From Eisenberg RL.
Radiology: an illustrated history. St Louis: Mosby–Year Book; 1992, p. 38.)FIGURE 1-2 First roentgen photograph of Mrs. Roentgen's hand. (From
Glasser O. Wilhelm Conrad Röntgen and the early history of the roentgen
rays. Springfield, Ill.: Charles C Thomas; 1933.)FIGURE 1-3 Roentgen's first communication. L e f t , First page of
handwritten manuscript (1895). M i d d l e , First page of published article on new
type of ray. R i g h t , Front cover of a reprint of initial paper. (From Eisenberg
RL. Radiology: an illustrated history. St Louis: Mosby–Year Book; 1992, p.
25.)
• Sven Ivar Seldinger develops percutaneous vascular catheterization (1952) (Figs. 1-4 and 1-5).
FIGURE 1-4 Sven Ivar Seldinger. (From Eisenberg RL. Radiology: an
illustrated history. St Louis: Mosby–Year Book; 1992, p. 442.)FIGURE 1-5 Seldinger technique (1953). A, Equipment. Stiletto is removed
and leader inserted through needle and catheter. B, Diagram of technique
used: ( 1 ) artery punctured and needle pushed upward, ( 2 ) leader inserted,
( 3 ) needle withdrawn and artery compressed, ( 4 ) catheter threaded onto
leader, ( 5 ) catheter inserted into artery, ( 6 ) leader withdrawn. (From
Seldinger SI. Catheter replacement of the needle in the percutaneous
arteriography: a new technique. Acta Radiol 1953;39:368–76.)
• Percutaneous revascularization is accomplished by Charles Dotter with coaxial dilators (1964)
(Figs. 1-6 and 1-7).FIGURE 1-6 Dotter coaxial Teflon catheter system consisting of 12F
catheter with tapered and beveled tip over inner 8F catheter with 0.044-inch
guidewire. (From Waltman AC, Greenfield AJ, Athanasoulis CA. Transluminal
angioplasty: general rules and basic considerations. In Athanasoulis CA,
Greene RE, Pfister RC, Roberson GH, editors. Interventional radiology.
Philadelphia: WB Saunders; 1982.)FIGURE 1-7 First percutaneous transluminal angioplasty (1964). A, Control
arteriogram showing segmental narrowing, with threadlike lumen of left
superficial femoral artery in region of adductor hiatus. B, Study immediately
after dilation with catheter having an outer diameter of 3.2 mm. C, Three
weeks after transluminal dilation, lumen remains open. Clinical and
plethysmographic studies indicated continuing patency more than 6 months
later. (From Dotter CT, Judkins MP. Transluminal treatment of
arteriosclerotic obstruction. Circulation 1964;30:654–70.)
• Transcatheter embolotherapy is performed by Charles Dotter to control acute upper
gastrointestinal bleeding (1970).
• Lazar Greenfield pioneers caval interruption with a vena cava filter (1973) (Fig. 1-8).FIGURE 1-8 Kimray-Greenfield filter. (From Dedrick CG, Novelline RA.
Transvenous interruption of the inferior vena cava. In Athanasoulis CA,
Greene RE, Pfister RC, Roberson GH, editors. Interventional radiology.
Philadelphia: WB Saunders; 1982.)
• Andreas Gruentzig performs percutaneous angioplasty (1977) (Figs. 1-9 and 1-10).FIGURE 1-9 Percutaneous transluminal coronary angioplasty (1979). A,
Stenosis of coronary artery. B, Double-lumen balloon catheter is introduced
with guiding catheter positioned at orifice of left or right coronary artery. At
tip of dilating catheter is a short soft wire to guide catheter through vessel.
Proximal to wire is a side hole connected to main lumen of dilating catheter.
This lumen is used for pressure recording and injection of contrast material.
Dilating catheter is advanced through coronary artery with balloon deflated.
C, Balloon is inflated across stenosis to its predetermined maximal outer
diameter, thereby enlarging lumen. After balloon deflation, catheter is
withdrawn. (From Grüntzig AR, Senning A, Siegenthaler WE. Non-operative
dilation of coronary artery stenosis. Percutaneous transluminal coronary
angioplasty. N Engl J Med 1979;301:61–8. Copyright 1979 Massachusetts
Medical Society. All rights reserved.)
FIGURE 1-10 Transluminal dilation of coronary artery stenosis (1978). L e f t ,
Initial angiogram in 43-year-old man with severe angina pectoris reveals
severe stenosis of main left coronary artery. M i d d l e , After passage of dilation
catheter, distensible balloon segment was inflated twice to a maximum outer
diameter of 3.7 mm. R i g h t , Postprocedure angiogram showing good result
without complications. (From Grüntzig AR. Transluminal dilation of coronary
artery stenosis. Lancet 1978;1:263.)
• Chemoembolization was performed by Cato (1981).
• Julio Palmaz develops the endovascular balloon-expandable stent (1985).
• Juan C. Parodi, Julio C. Palmaz, and H. D. Barone develop stent-grafts (1990).=
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Endovascular Milestones
November 18, 1895, was a day of historical signi cance. In a physics laboratory in the southern
part of Germany, Conrad Wilhelm von Roentgen accidentally discovered x-rays. The mysterious
rays illuminated medical science, and radiology was born. From this serendipitous discovery,
image-guided minimally invasive procedures evolved to provide patients with therapeutic
options in the management of vascular and nonvascular diseases.
This chapter is neither comprehensive nor complete. Of the many potential technologic
advances, arterial and venous endovascular therapy is the focus in this section. Later in the
chapter, the history of nonvascular interventions is covered.
Arterial Endovascular Therapy: Revascularization and Vessel Reconstruction
An English dentist, Dr. Charles Stent, developed a thermoplastic material for taking impressions
of toothless mouths in 1856. Thus the “stent” may be considered a “sca old.” For purposes of this
discussion, a stent is used for reconstruction in the vascular (or nonvascular) systems.
Percutaneous vascular catheterization as a viable endovascular technique was described in
June 1952, when Sven Ivar Seldinger presented his idea of replacing an arteriography needle
with a catheter. Translumbar aortography and direct carotid puncture were e ectively relegated
to historical descriptions in textbooks.
The technique of percutaneous revascularization advanced rapidly in 1964, when Charles
Dotter used coaxial “pencil-point” dilators to treat a super cial femoral artery stenosis. The era
of image-guided revascularization of the lower extremities had begun.
Although Dotter was successful in dilating femoral arterial stenoses, the use of coaxial
“pencilpoint” dilators (Van Andel Catheters [Cook Inc., Bloomington, Ind.]) required progressive
enlargement of the percutaneous puncture site. Development of the angioplasty balloon by
Andreas Gruentzig in 1977 resulted in another major step forward that allowed the percutaneous
arterial entry site to be kept to a minimum (see Figs. 1-9 and 1-10). Early balloon designs were
hampered by uneven balloon dilation and frequent rupture. Such events often led to
pseudoaneurysm formation or dissections and resulted in vessel thrombosis.
The arterial metallic stent was invented in the 1980s by Julio Palmaz at the University of
Texas Health Science Center in San Antonio. Dr. Palmaz described his stent in 1985 and
continued work on his device in 1986. Later developments included the use of a stent design
consisting of a single stainless steel tube with parallel staggered slots in the wall. When the
stainless steel tube was expanded, the slots formed diamond-shaped spaces that resisted arterial
compression. This design became the rst stent approved by the U.S. Food and Drug
Administration (FDA) for vascular use.
Stanley Baum and Moreye Nusbaum pioneered catheter embolization in the mid-1960s for the
purpose of treating acute gastrointestinal bleeding. In 1970, Charles Dotter reported utilizing an
autologous clot as the embolic agent to control acute upper gastrointestinal bleeding by selective
embolization of the right gastroepiploic artery in a patient who was a poor surgical candidate.
Robert White used this technique in 1974 to control bleeding duodenal ulcers when the
hemorrhage was unresponsive to intraarterial injections of vasopressin.
Chemoembolization was largely pioneered by the Japanese urologist Cato in 1981. Cato used
particles about 200 µm in size to demonstrate that chemoembolization with microcapsules
containing chemotherapeutic agents was superior to local intraarterial injection of antitumor
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Stent-grafts, pioneered by Juan Parodi and Charles Dotter, became the major impetus for
future endovascular reconstruction procedures used to exclude an aneurysm, close an
arteriovenous stula, and reconstruct the central lumen of a dissected vessel. Speci cs of the
history of endovascular grafts is worth mentioning. The technology has fundamentally changed
the management of diseases of the abdominal and thoracic aorta.
The rst abdominal aortic aneurysm (AAA) was described by Andreas Vesalius in the 16th
century. By the 1800s, aortic ligation had become the surgical procedure of choice when
attempting to treat iliac and abdominal aortic aneurysms. The longest survivor was a patient of
Keen in 1899, who survived 48 days after aortic ligation at the diaphragm for a ruptured AAA.
This was deemed a great success because previous aortic ligations for iliac aneurysms performed
by Astley Cooper in 1817 and J.H. James in 1829 resulted in patient death within 48 hours. As
the years passed, many others attempted aortic ligations, and most were met with similar results;
the most common mechanism of failure was ligature erosion into the aorta and massive
hemorrhage. In April of 1923, over 100 years after Cooper's rst attempts, Rudolph Matas
performed the rst successful aortic ligation on a patient with a syphilitic aortic and bilateral
common iliac aneurysms, using cotton tape. The patient survived for 17 months before
succumbing to tuberculosis.
The subsequent evolution of aortic aneurysm repair involved many varied techniques.
Physicians experimented with di erent variations of aortic ligation, wires to induce thrombosis,
and most notably, reactive polyethylene cellophane wrapping of aneurysms. This particular
technique was performed on Albert Einstein in 1949; however, he eventually died of an AAA
rupture 6 years later. In 1951, the rst homograft was used for AAA repair by Charles DuBost,
only to be superseded by nylon and then polytetraLuoroethylene (PTFE) grafts shortly
thereafter. Javid and Creech rst introduced surgical endoaneurysmorrhaphy in 1961, greatly
reducing the high mortality rates associated with aneurysm excision and graft repair.
With the advent of minimally invasive techniques for the treatment of AAAs, the evolution of
aneurysm repair changed dramatically. In the late 1970s, Juan Parodi had begun thinking about
endovascular aneurysm repair (EVAR) during his vascular surgery fellowship at the Cleveland
Clinic. After creating many rudimentary prototypes of varying designs, he became convinced
that AAA repair was possible without laparotomy. However, he continuously ran into two
problems: (1) the mechanics of delivering a minimally invasive system into the precise location
needed, and (2) the absence of a fastening device that would take the place of surgical sutures in
securing the graft in place and creating a seal between the intravascular graft and vessel wall.
The solution to these challenges came when Parodi met Julio Palmaz at the Transcatheter
Cardiovascular Therapeutics meeting in Washington, DC, in 1988. Palmaz was attending to
discuss a new stent design. Parodi was informed that Palmaz was presenting and thus was
encouraged to attend. It became apparent to Parodi that the Palmaz design was precisely what
he was looking for: a device with a high radial force (i.e., a balloon-expandable stent) that was
deployed using endovascular techniques and would provide placement, precision, a secure
anchor, and an aortic wall seal that his EVAR concept required. Palmaz was initially
apprehensive about joining the project because of his many professional commitments and
perceived limitations of his device in the aorta. However, he later admitted that he envisioned his
stent playing a role in aneurysm repair as early as 1986. Ultimately he decided to join e orts
with Parodi. Work then began on the rst EVAR in both Buenos Aires, where Parodi worked at
the Instituto Cardiovascular de Buenos Aires (ICBA), and San Antonio, where Palmaz was Chief
of Special Procedures at the University of Texas Health Science Center. During their e orts to=
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perfect the device and the technique, Parodi was searching for an ideal candidate for the rst
EVAR.
On September 7, 1990, two patients were to undergo the new procedure, to be performed by
both Parodi and Palmaz at the cardiac catheterization laboratory of ICBA. During the rst
procedure, the proximal portion of the stent was deployed just inferior to the renal arteries, and
the distal portion placed just superior to the aortic bifurcation. The postprocedure angiogram
displayed a completely excluded aneurysm, concluding the rst EVAR procedure. The second
patient was converted to traditional surgical AAA repair, because the proximal portion of the
stent was deployed too low in the aorta, and the distal end of the graft ended in one common
iliac artery. It was not until later that Parodi realized that the reLection of pressure waves from
the aortic bifurcation and iliac arteries would cause an endoleak and failure of a single stent
device.
This initial experience provided Parodi and Palmaz with clinical insight into patient bene ts
such as improvements in recovery time and quality of life, using an endovascular approach. The
rst patient quickly recovered and was discharged without complications, while the second
remained intubated in the intensive care unit. Additionally, the second case provided the team
with a possible mechanism of failure for their new procedure and delivery system. Over time, the
procedure, delivery system, and methods of Parodi's team evolved. By December of 1992, 24
patients had undergone EVAR by one of three techniques that had evolved since the first case, the
most common being an aorto-uni-iliac approach with contralateral common iliac embolization
and femoral-femoral bypass. Prior to this, an interventional radiologist from Buenos Aires,
Claudio Schonholz, had also joined the international team and played a signi cant role in the
first EVAR performed in the United States.
In August of 1992, the vascular surgery department at Monte ore Medical Center in Bronx,
New York, was consulted on a 76-year-old male patient with a 7.5-cm infrarenal AAA with
several comorbidities that suggested he was not a candidate for open surgical repair. Frank Veith
and Michael Marin quickly contacted Parodi and began discussing the logistics involved in
traveling to South America, learning the procedure, and treating the aneurysm endovascularly.
After several meetings, and convincing Johnson & Johnson (who was producing the Palmaz
stent) executives to allow them to use a large Palmaz stent for the procedure (no FDA
Investigational Device Exemption existed for it yet), they were ready to proceed. On November
23, 1992, Parodi, Schonholz, Veith, Marin, and Jacob Cynamon performed the rst EVAR in the
United States, using a 22-mm Dacron prosthesis sewn over a large Palmaz-like stent. The patient
was discharged several days later and remained symptom free until his death 9 months later.
Death was due to problems unrelated to the EVAR procedure.
Although Parodi is often credited with the rst EVAR, it is important to mention that a
Ukrainian surgeon, Nicholas Volodos, published an article in 1986 describing the endovascular
repair of a traumatic thoracic aortic aneurysm with a homemade stent-graft. Also of note,
Harrison Lazarus was awarded a U.S. patent in 1988 for an endovascular stent-graft that
eventually served as the basis for the Guidant (Indianapolis, Ind.) Ancure device.
With advancements in technology and re nement of techniques, EVAR has become for selected
patients the standard of care for treatment of AAAs. By the end of 2010, it was estimated that
nearly three quarters of all abdominal aortic aneurysms in the United States were repaired
endovascularly. There are an estimated 1.1 million Americans between the ages of 50 and 84
diagnosed with an AAA, and over 15,000 deaths annually due to abdominal aortic aneurysms, so
it is no surprise that this minimally invasive treatment option continues to evolve.=
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Venous Endovascular Therapy: Caval Interruption
Treatment of venous thromboembolic disease has also rapidly evolved. Deep venous thrombosis
is one of the major causes of morbidity and mortality worldwide. “Caval interruption” with a
lter was initially performed via surgical cutdown by Mobbin and Uddin. In 1973, Lazar
Green eld introduced a cone-shaped surgically placed vena cava lter. Green eld pioneered his
work with the Kimray Corporation. This device was rst deployed percutaneously in 1984. The
diameter of the sheath for the lter was 29F (outer diameter [OD]). Later developments reduced
Greenfield's percutaneous puncture size from 29F (OD) to 16F (OD).
Because all permanent vena cava lters are associated with complications, including caval
thrombosis (3%-40%), recent advances have provided patients at risk for venous thromboembolic
disease with “optional devices,” such as vena cava lters that may be permanent or removed, the
latter when the patient's “window of vulnerability” has clinically passed. Removable devices
were historically called temporary lters and were classi ed as either tethered or retrievable. A
more accurate term in current clinical use is an optional filter. Optional implies that the device may
either be a permanent implant or be used for a short interval. A tethered inferior vena cava (IVC)
lter consists of a lter attached to a central venous catheter. A retrievable IVC lter is a device
deployed in the IVC that attaches to the IVC wall with hooks but has no external tether. (The FDA
approved use of the rst tethered temporary vena cava lter in the United States in the early
1990s.) This tethered device (Tempo lter [B. Braun, Evanston, Ill.]), placed in a young trauma
patient, remained in place for 13 days and trapped a large embolus, thereby preventing a
potentially life-threatening pulmonary embolic event.
The FDA approved optional vena cava lters in the United States in 2003. The Recovery Filter
(Bard Peripheral Vascular, Tempe, Ariz.), a permanent implant with the “option to remove” at
any future date, was rst deployed in the United States in July 2003. Since 2003, the Günther
Tulip (Cook Medical, Bloomington, Ind.), the Opt Ease (Cordis Endovascular, Warren, N.J.), and
other lters have also received FDA approval as optional vena cava lters. Thus, management of
venous thromboembolic disease has further evolved with newer therapeutic options for patients
who are at risk for pulmonary emboli but have a contraindication to or have had a complication
of anticoagulant therapy.
Summary
Arterial and venous endovascular procedures continue to progress rapidly. Future developments
that might take place include continued use of mechanical devices in the vascular system,
combination therapies to rapidly lyse and remove residual thrombi, further design modi cations
in endovascular devices to reduce the risk of metal fatigue/fracture, and the application of newer
technologies to reduce intimal hyperplasia (e.g., drug-eluting stents). Such improvements will,
one hopes, provide solutions for some of the limitations of our current technology.
Key Points
• Percutaneous vascular access is a technique proposed and used by Sven Ivar
Seldinger.
• Several pioneers who made contributions to the endovascular procedures used today
include Charles Dotter, Andreas Gruentzig, Juan Parodi, and Julio Palmaz.
• The word stent (named after Charles Stent) originated with the development of
dental technology.• Advances in the use of newer vena cava filters include “optional” vena cava filters.
Historical Highlights of Nonvascular Image-Guided Therapy
• Wickbom, Weens, and Florence directly opacified the urinary tract with a needle (1954) (Fig.
1-11).
FIGURE 1-11 Antegrade pyelography (1954). After direct puncture of the
left renal pelvis, contrast material demonstrates dilation of the pelvis and
upper part of the ureter. There is complete obstruction of the ureter at the
pelvic inlet ( a r r o w ).
• Percutaneous urinary tract drainage is accomplished by Goodwin and colleagues (1955) (Figs.
1-12 and 1-13).FIGURE 1-12 Percutaneous trocar nephrostomy (1955): method and
landmarks. Optimum puncture site is usually about five fingerbreadths lateral
to midline and at a level where a 13th rib would be. (From Wickbom I.
Pyelography after direct puncture of the renal pelvis. Acta Radiol
1954;41:505–12.)FIGURE 1-13 Cross-sectional anatomy of left renal area (after Brodel).
About 2 inches of tubing is allowed to coil in hydronephrotic pelvis. (From
Wickbom I. Pyelography after direct puncture of the renal pelvis. Acta Radiol
1954;41:505–12.)
• Percutaneous biopsy of opacified lymph nodes is described by Sidney Wallace (1961).
• Percutaneous transhepatic cholangiography is described by Evans et al. (1962) (Fig. 1-14).
FIGURE 1-14 Operative cholangiography (1931). L e f t , Radiograph
demonstrating biliary tract, with two sharply defined clear spaces in
retroduodenal portion and at level of papilla of Vater. R i g h t , Corresponding
diagram with extracted calculi superimposed. Superior calculus is size of a
hazelnut and inferior one size of a chickpea. (From Mirizzi PL, Losada CQ.
Exploration of the bile ducts during an operation. Paper presented at the
Third Argentine Congress of Surgery, 1931, p. 694–703.)
• Drainage of an abdominal viscus (e.g., gallbladder, stomach) with a retrievable anchoring
device is described by Constantin Cope (1986).=
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• Percutaneous image-guided drainage is extensively used and described by Eric Vansonnenberg,
Peter R. Mueller, and Joseph T. Ferucci (1980s).
Urologic Interventions
In 1954, Wickbom opaci ed the renal pelvis directly by injecting contrast medium through a
long needle. Thus, the antegrade pyeloureterogram (antegrade nephrostogram) as we know it
was rst performed. The following year, Goodwin et al. used a “catheter through a needle” for
drainage. In 1965, Bartley used a guidewire technique for drainage of the urinary tract, and in
11976, Frenstrom and Johansson reported dilation of the nephrostomy tract for stone removal.
By 1978, Stables reviewed the techniques used in the performance of 516 nephrostomies
appearing in the medical literature. This series included 53 of his own patients. Thus,
percutaneous techniques had received increasing attention in the published medical literature
and were found to be a viable option for open surgical procedures.
Smith, in 1979, coined the term endourology. At that time he had begun work at the University
of Minnesota, where the scienti c/academic environment was conducive to new techniques.
Smith and Amplatz together developed numerous endourologic techniques, including the Amplatz
retention catheter in 1986.
In 1982, Castaneda-Zuniga and Amplatz published the technique for urinary stone removal.
Once the percutaneous tract was dilated, they used Luoroscopic guidance to extract stones with a
Randall forceps or a Dormia basket at the tip of the catheter. Coleman, in 1985, reported that the
results of percutaneous removal of stones had improved since the early 1980s to a success rate of
99% in a study of 450 patients.
Thus, the technique of percutaneous drainage of the urinary tract with subsequent
percutaneous removal of obstructing stones made signi cant advancements during the 1970s and
1980s. Today, percutaneous urinary tract interventions are an integral part of image-guided
therapy.
Biliary Interventions
Percutaneous transhepatic cholangiography and percutaneous biliary drainage are based on
needle/guidewire/catheter techniques developed simultaneously with endourology. Nonsurgical
management of biliary stones and strictures continues to be an essential part of the treatment of
patients with biliary disease. In 1973, Burhenne described a technique for extraction of retained
common duct stones through a T-tube tract.
The feasibility of percutaneous biliary duct dilation with balloon dilation catheters was
2reported by Berhenne in 1975. Berhenne performed the technique through a mature T-tube
tract. Molnar and Stockum described the dilation of biliary strictures via a transhepatic route in
31978.
In 1980, Constantin Cope developed a simple drainage catheter to reduce the problem of
nephrostomy tube dislodgement. Foley or Malecot nephrostomy drainage catheters were
frequently pulled out or became dislodged. The Cope loop catheter was one of the most
signi cant developments of nonvascular interventional procedures in the 1980s. A suture
coursing through the lumen of the catheter allowed a locking mechanism, which today is the
standard for most drainage catheters. Such catheters are used in the urinary tract and biliary
system and for drainage of percutaneous abscesses.
Percutaneous application of biliary endoprostheses (plastic or metallic) to palliate patients=
=
@
with malignant biliary obstruction was described by Dotter, Gianturco, and Ring, among others.
Lymph Node Applications
As early as 1933, Hudack and McMaster used blue dye as a contrast agent to visualize the
lymphatic system. The surgeon Servele dissected lymphatics in 1994 and inserted a needle,
followed by the injection of Thorotrast.
Percutaneous biopsy of opaci ed lymph nodes (opaci ed with contrast material) was described
by Sidney Wallace in 1961. The diagnostic and therapeutic potential of lymphangiography
brought oncologic interventions to the forefront.
Other Nonvascular Interventions
The ability to nonsurgically access an abdominal viscus (percutaneous gastrostomy, etc.) was
improved largely through the innovative e orts of Constantin Cope. Cope developed a
sutureanchoring device. The retrievable anchoring device was reported by Cope in 1986 after he
successfully drained the gallbladder and stomach without leakage. The technique of percutaneous
abscess drainage was applied and described extensively by E. Vansonnenberg, P.R. Mueller, and
J.T. Ferucci. Drainage of a percutaneous abscess or Luid collection is an integral part of
imageguided nonvascular patient management.
Key Points
• Nonvascular percutaneous interventions are an integral part of image-guided
therapy.
• Significant advancements have allowed nonsurgical management of multiple
medical conditions that previously required operative (open) procedures.
• Important percutaneous techniques in nonvascular interventions include those in the
urinary tract, biliary system, lymphatic system, gastrointestinal tract, and drainage
of abdominal fluid collections.
Acknowledgment
The authors would like to thank Shundra Dinkins, Toni Acfalle, and Dana Murphy for their
expertise in preparation of this manuscript.
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Vascular Diagnosis
OUTLINE
Chapter 2: Noninvasive Vascular Diagnosis
Chapter 3: Invasive Vascular DiagnosisC H A P T E R 3
Invasive Vascular Diagnosis
John A. Kaufman
Invasive vascular imaging is based on the technique described by Sven Ivar Seldinger in 1953
1(Fig. 3-1). This elegant innovation, now known by Seldinger's name, eliminated the need for
surgical exposure of a blood vessel before catheterization, thus allowing the transfer of
angiography from the operating room to the radiology department. Virtually all vascular
invasive procedures and devices use this technique.
FIGURE 3-1 Seldinger technique. A, Percutaneous puncture of blood
vessel with hollow needle. B, Introduction of atraumatic guidewire through
needle into blood vessel lumen. C, Needle is removed while guidewire
remains in place. Compression over puncture secures guidewire and
prevents bleeding. D, Angiographic catheter is advanced into vessel over
guidewire. (From Kadir S. Diagnostic angiography. Philadelphia: WB
Saunders; 1986.)
Preprocedural Patient Evaluation and Management
Every invasive procedure begins with a patient evaluation, determination of the appropriateness
of the examination, and formulation of a procedural plan. In most cases the angiographer
performing the procedure will have seen the patient previously in consultation and assumedprimary responsibility for management of the disease to be diagnosed. A brief directed history
should be obtained, with attention to the symptoms or signs that precipitated the study. Essential
historical areas to cover include prior surgical procedures (especially vascular); evidence of
atherosclerotic disease in “index” vascular beds, such as prior myocardial infarction or stroke;
diabetes, with attention to medications; status of renal function; allergies; and known previous
exposure to iodinated contrast agents. O0 ce records or the patient's chart should be reviewed for
similar information. Special attention should be applied to operative notes and reports from
previous angiograms, because these provide valuable information that may alter the entire
approach to the procedure. Most importantly, personal review of old angiograms or correlative
imaging is essential before embarking on an invasive procedure.
The preprocedural physical examination is focused on the status of the vascular system and
selection of a vascular access site. The person who will perform the procedure should conduct this
examination. The quality of the pulses and the presence of an aneurysm (as suggested by a broad
prominent pulse) should be recorded using a consistent system. Suspected integumentary
infection, fresh surgical incisions, a large abdominal pannus, or a scar over the vessel all impact
selection of an access site. Pulses distal to the anticipated access site must be evaluated because
one of the potential complications of angiography is distal embolization. Furthermore, if an
intervention is performed, this baseline information is important to help determine procedural
endpoints. The physical examination should include both right and left sides of the patient so
that a di3erent access site can be used during the procedure if necessary. When an upper
extremity approach is anticipated, the brachial blood pressure in both arms must be obtained.
2,3Patients should be well hydrated before the procedure. Outpatients should not be instructed
to fast after midnight but encouraged to drink clear liquids until 2 hours before their scheduled
appointment. In the preprocedural area, an intravenous infusion of 5% dextrose in 0.5% normal
saline should be begun at 100 mL/h in normal patients. Fluid rates and characteristics should be
adjusted in diabetics, patients on dialysis, and patients with congestive heart failure. Inpatients
should have an established intravenous infusion in place before arriving in the angiographic
suite. Most hospitals have established guidelines for oral intake before invasive procedures that
must be followed, but remember that these are generally not designed for patients about to
receive large doses of nephrotoxic contrast materials.
There are no laboratory studies that are absolutely necessary before starting an invasive
vascular procedure; most problems that can be predicted from abnormal laboratory studies occur
after the catheter is removed (e.g., bleeding, renal failure). A low platelet count is the single
4most important predictor of postprocedural bleeding complications. The commonly acquired
minimal laboratory studies are coagulation (international normalized ratio [INR], prothrombin
time [PT], activated partial thromboplastin time [APTT], and platelet count) and serum
creatinine value. Patients with renal failure undergoing central venous procedures that might
entail intracardiac manipulation (e.g., central line placement) may require measurement of
serum potassium concentration.
When the PT or INR is abnormal, fresh frozen plasma given the day or night before is useless
or even dangerous because an INR drawn just after the plasma has been infused may be normal,
but by the time the procedure is performed, the e3ect may dissipate. Fresh frozen plasma infused
shortly before and during the procedure provides maximal correction when it is needed most. An
abnormal APTT is usually due to administration of unfractionated heparin, which can be turned
o3 when the patient arrives in the angiography suite. Because the half-life of unfractionatedheparin is about 90 minutes, most patients will correct su0 ciently for manual compression by
the end of the procedure. Perhaps more importantly, platelet transfusion to restore a count to
more than 50,000/µl is an empirical cuto3 used in many departments for patients having an
arterial access.
In the presence of an abnormal serum creatinine value, the risk of postprocedural renal failure
should be weighed against the beneBts of the procedure. Every hospital and practice should have
guidelines for contrast administration to patients with abnormal renal function. Regardless of the
renal protective strategy, the patient should be well hydrated before and after the examination.
Renal protective strategies should be followed to maximize renal protection.
Basic Safety Considerations
Operator precautions against exposure to body Cuids should be applied to all situations, even for
5patients with no known risk factors. Masks, face shields or other protective eye wear, sterile
gloves, and impermeable gowns are the minimal measures. Closed Cush and contrast systems
decrease the risk of splash exposures. All materials used during the case should be disposed of in
waste containers designed and labeled for biological waste.
Sharp devices (e.g., needles, scalpels) should be carefully stored on the work surface in a red
sharps container or removed immediately after use. Recapping needles is not advised owing to
the puncture risk. The best sharps containers contain a foam block into which the point of the
sharp device can be safely imbedded. At the end of the case, the angiographer can dispose of the
sharps in one of the ubiquitous hard red plastic sharps receptacles. Puncture wounds from
contaminated needles or scalpels are not only painful but also potentially life-altering events. If
an accidental splash, puncture, or any other exposure occurs, immediate consultation with a
physician experienced in management of exposure to occupational biohazards is essential.
6Radiation exposure to the patient and sta3 should be kept to a minimum. Use Cuoroscopy
only when needed to move catheters or guidewires. Prolonged Cuoroscopy at high magniBcation
7with the x-ray tube in one position has been associated with radiation burns to the patient.
Exposure can be reduced during long cases by use of pulsed Cuoroscopy modes. The typical pulse
rate of 15 pulses per second can be decreased by 50% or more with only a minor degradation in
image quality.
Accumulative radiation exposure to the angiographer can be substantial. Angiographers should
wear wraparound lead, thyroid shields, leaded glasses, and radiation badges. Careful coning of
the x-ray beam during the case can reduce scatter. The operator's hands should never be seen on
the Cuoroscope during the case. When the angiographer must remain in the procedure room
during Blming, portable leaded shields should be positioned between the x-ray source and the
physician.
Ergonomic considerations are important during invasive vascular imaging. Many
8angiographers develop degenerative spine disease in the neck and back. Careful attention to
the design of angiographic suites, especially the positioning of controls and monitors, can reduce
twisting and bending. Similarly, patients should be positioned on the procedural table to
minimize contortions on the part of the operator. The patient's comfort also requires careful
consideration. For long procedures, careful padding of pressure points, especially when the
patient is under general anesthesia, is important.
ToolsAccess Needle
All angiographic procedures begin with a vascular access needle. There is great variety in
vascular access needles, but all are designed to allow introduction of a guidewire through a
central channel (Fig. 3-2). The simplest needle is a one-piece open needle with a sharp beveled
tip. The guidewire is introduced directly through the needle once the tip is fully within the
bleeding vessel lumen. This style of needle can be used for both arterial and venous punctures.
Two-piece needles usually have a central sharp stylet that obturates the lumen and extends
slightly beyond the needle tip. These needles have a blunted atraumatic beveled tip when the
stylet is removed. The sharp stylet allows the needle to puncture the vessel, but once it is
removed the risk of vascular injury from the blunt needle tip is theoretically removed. The stylet
can be solid or hollow. In the latter case, blood may be visualized on the stylet hub once the
vessel lumen is entered. With all styleted needles, the stylet must be removed to insert the
guidewire. Needles with stylets are generally used only for arterial punctures. The most common
sizes for vascular access needles of the type described above are 19 or 18 gauge in diameter and
to 5 inches in length.FIGURE 3-2 A, Typical access needles. Left to right, 18-gauge Seldinger
needle with hollow, sharp, central stylet that extends beyond blunt tip of
needle; stylet; Seldinger needle with stylet removed; 18-gauge sharp, hollow
(“one-wall”) needle; 21-gauge “microaccess” needle. B, Microaccess system.
Left to right, 21-gauge needle; 0.018-inch guidewire for insertion through
needle; 5F dilator with central 3F dilator tapered to 0.018-inch guidewire; 5F
dilator with 3F dilator removed that accepts 0.038-inch guidewire; 3F dilator.
(From Kaufman JA, Lee MJ, editors. Vascular and interventional radiology:
the requisites. St. Louis: Mosby; 2004.)
Microaccess systems in which a very small-diameter access needle is used to enter the vessel
and then converted to a larger short, plastic introducer with a larger lumen are very useful for
both arterial and venous punctures. These systems usually employ a sharp, open, bevel-tipped
21-gauge needle for access. These needles are often modiBed to enhance visualization by
ultrasound during the access procedure. After entering the blood vessel, a short, Coppy-tipped
0.018-inch guidewire is inserted. The needle is removed over the guidewire and exchanged for a
4F or 5F dilator through which a 3F dilator has been coaxially inserted. Once the dilator
assembly has been inserted, the 0.018-inch guidewire and the 3F dilator are removed, leaving thedilator with the larger lumen behind.
Guidewires
Guidewires are available in a number of thicknesses, lengths, tip conBgurations, sti3nesses, and
materials of construction (Fig. 3-3). In general, the guidewire thickness (always referred to in
hundredths of an inch—e.g., 0.038-inch) should be the same as or slightly smaller than the
diameter of the lumen at the tip of the catheter or device that will slide over it. Guidewires that
are too big will jam, usually at the tip of the catheter. However, if a guidewire is much smaller
than the end hole of the catheter or device, there will be a gap between the guidewire and
catheter that can cause vessel injury or prevent smooth movement over the guidewire.
FIGURE 3-3 Common guidewires. Left to right, Straight 0.038-inch;
Jtipped 0.038-inch with introducer device (arrow) to straighten guidewire
during insertion into needle hub; angled high-torque 0.035-inch; angled
hydrophilic-coated 0.038-inch nitinol wire with pinvise (curved arrow) for fine
control; 0.018-inch platinum-tipped microwire. (From Kaufman JA, Lee MJ,
editors. Vascular and interventional radiology: the requisites. St. Louis:
Mosby; 2004.)
The most commonly used style of guidewire has a central sti3 core around which is tightly
wrapped a smaller wire, just like a coiled spring (Fig. 3-4). The outer wire is often welded to the
core at the back end but not the tip. The purpose of the coiled outer wrap is to decrease the area
of contact between the surface of the guidewire and the tissues. A Bne safety wire runs along the
length of the inside of the guidewire between the inner core wire and outer wrap and is welded
to the outer wrap at both ends. This safety wire prevents the outer wrap from unwinding should
the weld break. This is where the term safety guidewire originated.FIGURE 3-4 Basic construction of common guidewires. 1 and 2, Curved
and straight safety guidewires with outer coiled spring wrap, central stiffening
mandril welded at back end only, and small safety wire (arrow) welded on
inside at both ends. 3, Movable-core guidewire in which mandril can be slid
back and forth and even removed completely to change wire stiffness, using
handle incorporated into guidewire (arrow). 4, Mandril guidewire in which soft
spring wrap is limited to one end of guidewire (arrow). Remainder of
guidewire is a plain mandril. 5, Mandril guidewire coated with hydrophilic
substance (arrow). (Drawings reproduced with permission from Cook Group
Inc., Bloomington, Ind.)
The composition and thickness of the inner core determine the degree of guidewire sti3ness.
Guidewires that are very Cexible are important for negotiating tortuous or diseased vessels. Sti3
guidewires provide the most support for introducing catheters and devices. A movable core
guidewire is one in which the core is not welded to the tip but can be slid in and out of the spring
wrap to adjust the guidewire sti3ness as necessary. The mandril guidewire is an important
design type in which the outer wrap is limited to the soft tip of guidewire. The majority of the
guidewire is solid wire. This is a common construction for microguidewires (0.018 inch or
smaller) or for extra-rigid large-diameter guidewires.
The features of the taper of the core at the leading end of the guidewire determine the softness
or “Coppiness” of the tip. The length and transition of the taper deBne the characteristics of thetip. The longer and more gradual the transition, the longer and Coppier the tip. Bentson
guidewires and movable core guidewires with the core retracted have the softest tips. With all
guidewires, it is the soft end that goes in the patient.
A curved tip at the end of the guidewire provides an additional degree of safety in diseased
vessels. As the guidewire is advanced, the rounded presenting part bounces over plaque rather
than digging into it. A curve can be added to most straight guidewires by gently drawing the
Coppy tip across a Brm edge (e.g., a Bngernail, closed hemostat), much like curling a ribbon. A
special type of wire is the tip-deCecting guidewire, which allows the operator to mechanically
vary in the radius of the curve while in the patient. These guidewires have sti3 tips and should
never be advanced beyond the end of the catheter.
A wide range of special-purpose guidewires such as wires coated with slippery hydrophilic
substances, highly torquable guidewires, kink-resistant nitinol-based wires, and microwires are
available. These guidewires have been the di3erence between routine success and failure in the
many challenging cases. The hydrophilic-coated guidewire is the most commonly used specialty
guidewire; its central core is coated with an outer layer of hydrophilic material. This coating
drastically reduces friction between the guidewire, blood vessel wall, and catheter. However,
unless kept moist, hydrophilic guidewires actually become much stickier than a regular
guidewire. When this happens, it is almost impossible to advance a catheter over the guidewire
and easy to inadvertently pull the entire guidewire out of the body during an exchange. Of note,
these guidewires should not be inserted through vascular access needles because the
nonradiopaque coating can be easily sheared off by the metal edge of the needle if withdrawn.
The length of the average guidewire used in angiography is 145 to 160 cm. In circumstances in
which a great deal of guidewire is needed inside the body, or the devices and catheters to be
placed over the guidewire are very long, an “exchange-length” guidewire (260-300 cm long) is
used. Extra-long guidewires are not used for routine cases because the excess length outside the
body is cumbersome and easily contaminated.
Dilators
Vessel dilators are short, tapered, plastic catheters usually made of a sti3er material than
diagnostic angiographic catheters (Fig. 3-5). The sole purpose of a dilator is to spread the soft
tissues and the blood vessel wall to make introduction of a catheter or device easier. By inserting
progressively larger dilators over a guidewire, a percutaneous puncture with an 18-gauge needle
can be increased to almost any size. Sequential dilatation is important to minimize trauma to the
vessel, since incremental steps in size (1F-2F) can be accomplished with much less resistance than
one giant step. The initial dilator size after puncture with an 18-gauge access needle should be
5F. Larger dilators can follow as necessary. Dilatation of a puncture site beyond 50% of the
expected diameter of the artery may obviate manual compression, because the muscular layer of
the artery can no longer contract after removal of the catheter.FIGURE 3-5 Vascular dilators. Standard taper (arrow) and longer taper
(arrowhead) “Coons” tip, useful when more gradual dilation is required.
(From Kaufman JA, Lee MJ, editors. Vascular and interventional radiology:
the requisites. St. Louis: Mosby; 2004.)
Catheters
Angiographic catheters are usually made of plastic (polyurethane, polyethylene, TeCon, or
nylon). The exact catheter material, construction, coatings, inner diameter, outer diameter,
length, tip shape, sidehole pattern, and endhole dimensions are determined by the intended use
(Fig. 3-6). Catheters used for nonselective aortography are thick walled (to handle large-volume
high-pressure injections) and often curled at the tip (the “pigtail,” which keeps the end of the
catheter away from the vessel wall) with multiple side holes proximal to the curl (so the majority
of the contrast medium exits the catheter in a cloud). Conversely, selective catheters are
generally thinner walled with a single end hole because injection rates are lower and directed
into a small vessel. Precise control of the movement of a selective catheter, especially at the tip,
is important. These catheters usually have Bne metal or plastic strands incorporated into the wall
(“braid”) (Fig. 3-7). This results in a catheter tip that is responsive to gentle rotation of the shaft.
FIGURE 3-6 Common catheter shapes. 1, Straight; 2, Davis (short angled
tip); 3, multipurpose (“hockey-stick”); 4, headhunter (H1); 5, cobra-2
(cobra1 has tighter curve, cobra-3 has larger and longer curve); 6, Rösch celiac; 7,
visceral (very similar to Simmons 1); 8, Mickelson; 9, Simmons-2; 10, pigtail;
11, tennis racket. (From Kaufman JA, Lee MJ, editors. Vascular and
interventional radiology: the requisites. St. Louis: Mosby; 2004.)FIGURE 3-7 Drawing illustrating fine wire braid in shaft of a selective
catheter. (Reproduced with permission from Cook Group Inc., Bloomington,
Ind.)
Catheter outer size is described in French gauge (3F = 1 mm), whereas the diameter of the end
hole (and therefore the maximum size of the guidewire the catheter will accommodate) is
described in hundredths of an inch. The length of the catheter is described in centimeters (usually
between 65 and 100 cm). The shape of the tip is named for either something the catheter looks
like (“pigtail,” “cobra,” “hockey stick”), the person who designed it (Simmons, Berenstein,
Rösch), or the intended use (celiac, left gastric, “head-hunter”) (see Fig. 3-6). There are so many
di3erent catheters that no one department can or should stock them all. The shape of some
catheters (especially TeCon and polyethylene) can be modiBed by heating the catheter in steam
while bending it into the desired conBguration. Rapidly dunking the catheter into cool sterile
water “sets” the shape.
Complex catheter shapes must be re-formed inside the body after insertion over a guidewire.
Any catheter will resume its original shape, provided there is su0 cient space within the vessel
lumen and memory in the catheter material. Some catheter shapes cannot re-form spontaneously
in a blood vessel, particularly the larger recurved designs like the Simmons. There are a number
of strategies for re-forming these catheters (Figs. 3-8 to 3-12). These same techniques can be used
to create a recurved catheter from a simple angled selective catheter by forming a Waltman loop
9(Fig. 3-13).FIGURE 3-8 Branch technique for re-forming a Simmons catheter. 1,
Catheter is advanced into branch over guidewire (dashed line). Aortic
bifurcation shown in this illustration. 2, Guidewire withdrawn proximal to origin
of branch but still in catheter. One may also remove guidewire and reinsert
stiff end to same point. Catheter is then twisted and advanced at same time.
3, Re-formed catheter. (From Kaufman JA, Lee MJ, editors. Vascular and
interventional radiology: the requisites. St. Louis: Mosby; 2004.)
FIGURE 3-9 Aortic spin technique for re-forming a Simmons catheter
(works best for Simmons 1). 1, Catheter is simultaneously twisted and
advanced in proximal descending thoracic aorta. Note wire is withdrawn
below curved portion of catheter. 2, Re-formed catheter. (From Kaufman JA,
Lee MJ, editors. Vascular and interventional radiology: the requisites. St.
Louis: Mosby; 2004.)FIGURE 3-10 Cope string technique. Easily re-forms any size Simmons
catheter. 1, Three to 4 cm of 4-0 Tevdek II (Deknatel Inc., Fall River, Mass.)
suture material (curved arrow) has been backloaded into catheter tip.
Catheter is then advanced (arrow) onto floppy-tipped guidewire (dashed
line). 2, Catheter has been advanced over guidewire into aorta, with suture
material exiting groin adjacent to catheter. Floppy portion of guidewire still
exits catheter, “locking” suture material in catheter tip. Suture material is
pulled gently (black arrow) as slight forward force applied to catheter (gray
arrow). 3, Simmons catheter has been re-formed. 4, Suture removed by first
retracting guidewire into catheter (dashed arrow), “unlocking” suture
material. Suture material can then gently be pulled out (black arrow). (From
Kaufman JA, Lee MJ, editors. Vascular and interventional radiology: the
requisites. St. Louis: Mosby; 2004.)FIGURE 3-11 Ascending aorta technique for re-forming a Simmons
catheter. 1, Floppy-tipped 3-J guidewire reflected off of aortic valve. Catheter
is advanced over guidewire. 2, Catheter advanced around bend in guidewire.
3, Retraction of guidewire completes re-formation. (From Kaufman JA, Lee
MJ, editors. Vascular and interventional radiology: the requisites. St. Louis:
Mosby; 2004.)FIGURE 3-12 Deflecting wire technique (unsafe for use in small or diseased
aortas). 1, Deflecting wire is positioned near tip of catheter. 2, Wire
deflected, curving the catheter as well. 3, With guidewire fixed, catheter is
advanced (arrow) to re-form Simmons catheter. (From Kaufman JA, Lee MJ,
editors. Vascular and interventional radiology: the requisites. St. Louis:
Mosby; 2004.)FIGURE 3-13 Waltman loop. This can be formed in any major aortic branch
vessel with braided selective catheters. A, Angled catheter is positioned over
aortic bifurcation. Note stiff end of guidewire at catheter apex (arrow). B,
Catheter is advanced and twisted, forming loop. C, Looped catheter has
been used to select ipsilateral internal iliac artery (arrow). (From Kaufman
JA, Lee MJ, editors. Vascular and interventional radiology: the requisites. St.
Louis: Mosby; 2004.)
Multiple side-hole straight or pigtail catheters are generally used for nonselective injections.
Straight catheters should be advanced over a guidewire; otherwise the tip may cause a dissection
or perforation. Pigtail catheters can be safely advanced in normal vessels once the pigtail has
reformed, but should be advanced over a guidewire in abnormal blood vessels.
Selective catheters are chosen based on the particular vessel or anatomy that will be studied
(Fig. 3-14). The technique used to catheterize a blood vessel with a selective catheter varies with
the type of catheter (Figs. 3-15 and 3-16). The Waltman loop is particularly useful in the pelvis
for selecting branches of the internal iliac artery on the same side as the arterial puncture.FIGURE 3-14 Choosing a selective catheter shape. A, Angled catheter
when angle of axis of branch vessel from aortic axis is low. B, Curved
catheter (e.g., cobra-2, celiac) when angle of axis of branch vessel is
between 60 and 120 degrees. C, Recurved catheter (e.g., SOS, Simmons)
when angle of axis of branch vessel from aorta is great. (From Kaufman JA,
Lee MJ, editors. Vascular and interventional radiology: the requisites. St.
Louis: Mosby; 2004.)FIGURE 3-15 How to use a cobra catheter. 1, Catheter advanced to
position proximal to branch over guidewire, then pulled down (arrow). 2,
Catheter tip engages orifice of branch. Gentle injection of contrast agent to
confirmed location. 3, Soft-tipped selective guidewire has been advanced into
branch. Guidewire is held firmly, and catheter is advanced (arrow). 4,
Catheter in selective position. (From Kaufman JA, Lee MJ, editors. Vascular
and interventional radiology: the requisites. St. Louis: Mosby; 2004.)FIGURE 3-16 How to use a Simmons catheter. 1, Catheter is positioned
above branch vessel with at least 1 cm of floppy straight guidewire beyond
catheter tip. 2, Catheter is gently pulled down (arrow) until guidewire and tip
engage orifice of branch. 3, Continued gentle traction results in deeper
placement of catheter tip. To deselect branch, push catheter back into aorta
(reverse steps 1-3). To un-form a Simmons catheter, apply continued
traction from this position. (From Kaufman JA, Lee MJ, editors. Vascular and
interventional radiology: the requisites. St. Louis: Mosby; 2004.)
Small catheters (3F or smaller outer diameter) that are specially designed to Bt coaxially
within the lumen of a standard angiographic catheter are termed microcatheters. These soft
Cexible catheters are typically 2F to 3F in diameter, with 0.010- to 0.027-inch inner lumens. They
are designed to reach far beyond standard catheters in small or tortuous vessels. These catheters
are technologically advanced and have a wide range of characteristics, such as sti3ness,
braiding, Cow rates, and hydrophilic coatings. The ability to reliably catheterize small arteries
without creating spasm, dissection, or thrombosis has allowed certain subspecialties (e.g.,
neurointerventional radiology) to Courish. When using a microcatheter, a standard angiographic
catheter that accepts a 0.038- or 0.035-inch guidewire is Brst placed securely in a proximal
position in the blood vessel. The microcatheter is then inserted through the outer catheter and
advanced in conjunction with a specially designed 0.010- to 0.025-inch guidewire through the
standard catheter lumen. Once a superselective position has been attained with the
microcatheter, a variety of procedures can be performed, including embolization, sampling, or
low-volume angiography. The small inner lumen and long length result in a high resistance to
Cow, so microcatheters are not used for routine angiography. Contrast and Cush solutions are
most easily injected through these catheters with 3-mL or smaller Luer-Lok syringes.
Guiding catheters are another class of catheters designed to make selective catheterization and
interventions easier. These catheters can be used in some situations to help position and stabilize
standard catheters. Guide catheters are nontapered catheters with extra-large lumens and a
simple shape that accepts standard-sized catheters and devices (Fig. 3-17). They are used in
circumstances in which standard catheters are di0 cult to position selectively. The larger outer
catheter can provide direction and stability for the inner standard catheter. Guiding catheter size
in French gauge refers to the outer diameter. This is the converse of the use of French sizes when
describing standard catheters. The inner diameter of the guide catheter is usually described in
hundredths of an inch, which must be converted to French gauge to determine which standard
catheter will fit (1F = 0.012 inch = 0.333 mm).FIGURE 3-17 Two examples of nontapered large-diameter guide catheters
that can accommodate standard 5F catheters. French size of guide
catheters refers to outer diameter. (From Kaufman JA, Lee MJ, editors.
Vascular and interventional radiology: the requisites. St. Louis: Mosby;
2004.)
Sheaths
Most vascular interventions and diagnostic procedures are performed through vascular access
sheaths. These devices of varying thickness and construction are open at one end and capped
with a hemostatic valve at the other (Fig. 3-18). The intravascular end is not tapered, although
the edges are carefully beveled to create a smooth transition to the tapered dilator used to
introduce the sheath over a guidewire. The valved end usually has a short, clear side-arm that
can be connected to a constant Cush (to prevent thrombus from forming in the sheath) or an
arterial pressure monitor. The purpose of the sheath is to simplify multiple catheter exchanges
through a single access site. When not using a sheath, it is unwise to downsize catheters during a
procedure (i.e., place a small catheter through a big hole in the artery) because of the risk of
bleeding. Devices that are irregular in contour or even nontapered can be introduced through a
sheath without fear of trauma to the device or access vessel. In some cases, a long sheath can
straighten a tortuous access artery.FIGURE 3-18 Typical hemostatic sheath. French size of sheaths refers to
inner diameter. (From Kaufman JA, Lee MJ, editors. Vascular and
interventional radiology: the requisites. St. Louis: Mosby; 2004.)
Sheaths are described by the maximum-sized device (in French gauge) that will Bt through the
sheath. Because the walls of the sheath have some thickness, this means the actual hole in the
blood vessel will be 1.5F to 2F larger than the sheath “size.” Sheaths are available in a variety of
lengths, depending on the requirements of the procedure. Short sheaths are more often used
during diagnostic procedures, and long sheaths are used for interventions.
The peel-away sheath is a useful type of sheath (Fig. 3-19). The proximal end of this sheath
terminates in two plastic wings, and there is no side port for Cushing. Many of these sheaths
have a break-away hemostatic valve. The sheath and dilator are introduced over a guidewire.
Once they are in position, the dilator is removed. If there is no hemostatic valve, the only way to
achieve hemostasis is to either block the open end of the sheath with a Bnger or clamp the
sheath. After inserting a device or catheter through the sheath, the plastic wings are pulled in
opposite directions parallel to the skin. This “peels” the sheath away in two long strips of plastic
and allows complete disengagement from the catheter without having to slide o3 of the back
end. The primary disadvantages of peel-away sheaths are that they kink easily, and those that
10are hemostatic are not designed for multiple catheter exchanges.FIGURE 3-19 Peel-away sheath. To peel sheath away, wings are pulled in
opposite directions at 90 degrees from catheter shaft. (From Kaufman JA,
Lee MJ, editors. Vascular and interventional radiology: the requisites. St.
Louis: Mosby; 2004.)
Contrast Agents
All the tools described previously are intended to facilitate delivery of a contrast agent into the
vascular system. The development of safe and well-tolerated contrast agents was equally as
11important to angiography as the Seldinger technique. The ideal contrast agent has excellent
radiopacity, mixes well with blood, is easy to use, is inexpensive, and does not harm the patient.
Iodinated contrast agents (which are based on benzene rings with three bound iodine atoms,
termed triiodinated contrast agents) turn out to be as close to ideal as currently possible.
There are two major classes of triiodinated contrast agents: nonionic and ionic (Table 3-1).
Ionic contrast agents use a nonradiopaque cation, usually sodium and meglumine
(Nmethylglucamine) but also sometimes magnesium and calcium. The result is a highly soluble,
low-viscosity, but high-osmolar (two particles per iodinated ring) contrast agent. High osmolarity
relative to human blood is believed to be a major contributing factor to adverse reactions to
contrast agents. Nonionic contrast agents have no electric charge, so cations are not needed. This
greatly reduces the osmolality of the contrast agent (one particle per iodinated ring), which
improves the safety proBle but increases viscosity. The two major classes of contrast agents are
further subdivided into monomeric (one triiodinated benzene ring) or dimeric (two linked
triiodinated benzene rings).TABLE 3-1
Contrast Agents
Class of Iodine Atoms Approximate Osmolality*
Contrast Commercial
Contrast per (300 mg L/mL
Agent Names
Agent Molecule Concentration)
Ionic Diatrizoate Hypaque, 3 1500-1700
monomer Renografin
Iothalamate Conray
Nonionic Iopamidol Isovue 3 600-700
monomer
Iohexol Omnipaque
Ioversol Optiray
Ioxilan Oxilan
Iopromide Optivist
Ionic dimer Ioxaglate Hexabrix 6 560
Nonionic Iodixanol Visipaque 6 300
dimer
*mOsm/kg water.
Adverse reactions to iodinated contrast agents are frequent, but the majority are minor, such
12,13as pain or nausea (Table 3-2). Most minor complications are linked to the osmolality of the
contrast agent, so the overall incidence is lower with nonionic contrast agents. Complications
such as nausea and emesis are believed to be related to a central nervous system mechanism and
are more frequent with venous than arterial injections. Late complications (occurring hours or
14days after the contrast exposure) are rare but include rash, urticaria, and parotitis.TABLE 3-2
Contrast Reactions: Reported Incidence Rates
Reaction Ionic Contrast Nonionic Contrast
Nausea 4.6% 1%
Vomiting 1.8% 0.4%
Itching 3.0% 0.5%
Urticaria 3.2% 0.5%
Sneezing 1.7% 0.2%
Dyspnea 0.2% 0.04%
Hypotension 0.1% 0.01%
Sialadenitis
Death 1 : 40,000 1 : 170,000
The two major adverse reactions to iodinated contrast agents are anaphylaxis and
contrast11induced renal failure. True anaphylaxis is distinguished from a vasovagal response by
tachycardia (in patients who are not on beta blockers) and respiratory distress. The incidence of
life-threatening anaphylaxis due to iodinated contrast is roughly 1 in 40,000 to 170,000. Mild
reactions (e.g., urticaria, nasal stu0 ness) occur more commonly, especially with ionic contrast.
Contrast reactions must be treated quickly and aggressively. The most common cause of death is
airway obstruction.
A patient with a history of prior contrast allergy should receive pharmacologic prophylaxis
12beginning at least 12 hours before the procedure (unless a true emergency exists) (Table 3-3).
Patients may label many symptoms experienced during prior contrast studies as “allergy,” such
as nausea, vagal nerve-mediated bradycardia and hypotension, or ischemic cardiac events.
Whenever the precise nature of the “allergic” reaction cannot be determined from the history,
corticosteroid prophylaxis is wise. Nonionic contrast media should be used exclusively in any
patient with a history of contrast allergy.
TABLE 3-3
Preparation of Patient with Contrast Allergy
Prednisone, 50 mg (oral), 13, 7, and 1 hour prior to the procedure
Cimetidine, 300 mg, intravenously on arrival in the angiography suite
Diphenhydramine (Benadryl), 50 mg, intravenously on arrival in the angiography suite
Use nonionic contrast
Renal failure after intravascular administration of iodinated contrast is more common in
patients with diabetes, preexisting renal insu0 ciency (serum creatinine ≥ 1.5 mg/dL), and
multiple myeloma. The exact mechanism is not known, but the classic Bndings are a rise in
creatinine concentration 24 to 48 hours after exposure to the contrast agent, peaking at 72 to 96
hours. Patients are usually oliguric but may be anuric. Management is usually expectant becausethe creatinine concentration will return to baseline in 7 to 14 days in most cases. However, in
patients with severe preexisting renal insu0 ciency and diabetes, the risk of permanent dialysis
may be as high as 15% despite protective measures (Table 3-4).
TABLE 3-4
Preventive Measures for Contrast-Induced Acute Renal Failure
Agent Protocol
Hydration 1 mL/kg D W for 12 hours before procedure; 0.5 mL/kg D W for 12 hours5 5
after procedure
Sodium 154 mmol/L at 3 mL/kg/h prior to procedure; 1 mL/kg/h for 6 hours after
bicarbonate procedure
N-acetylcysteine 1200 mg orally every 12 hours beginning 24 hours before procedure,
including one dose the morning of the angiogram and one dose the night
after procedure. Total of four doses.
Contrast medium is administered during angiographic procedures by hand or mechanical
injectors. Injection by hand is useful during the initial stages of the procedure, or for low-volume
and low-pressure angiograms in small vessels, or through precariously situated catheters. The use
of mechanical injectors is necessary for optimal contrast delivery, particularly when large
volumes or high Cow rates are needed. In addition, there is less radiation exposure to the
angiographer if a mechanical injector is used. Catheters are rated for both contrast Cow rates
(mL/s) and maximum injection pressure in pounds per square inch (psi). Exceeding these limits
may cause rupture of the catheter (usually at the hub) or premature termination of the injection
by the injector software. Meticulous technique is necessary when connecting a catheter to a
power injector to avoid air bubbles, contamination of the catheter, or disconnection during
injection.
Alternative Contrast Agents
The low but real incidence of adverse reactions to iodinated contrast agents has led to the use
of alternative contrast agents in selected circumstances. In particular, patients with past histories
of true anaphylactic reactions to iodinated contrast or with precarious renal function may be
considered for an alternative to iodinated contrast. Two alternative contrast agents have been
15,16described: carbon dioxide (CO ) gas and gadolinium chelates. Experience is most extensive2
with CO , which acts as a negative contrast agent. The gas temporarily displaces the blood in the2
lumen of the vessel, resulting in decreased attenuation of the x-ray beam. Digital subtraction
technique is essential for diagnostic imaging with CO (Fig. 3-20). The buoyant nature of CO2 2
relative to blood results in preferential Blling of anterior structures. The CO gas is extremely2
soluble in blood and rapidly excreted from the lungs. The low viscosity of CO is advantageous2
17for demonstration of subtle bleeding or during wedged hepatic vein portography. CO can be2
used for abdominal aortography, selective visceral injections, lower extremity runo3s, and most
venous studies. For abdomen studies it is helpful to administer intravenous glucagon to decrease
bowel peristalsis. CO is contraindicated in angiography of the thoracic aorta, cerebral arteries,2or upper extremity arteries owing to potential neurologic complications. Rarely, CO gas can2
cause a “vapor lock” in a small vessel, which obstructs blood Cow and induces distal ischemia. An
excessive volume of gas in the heart can obstruct the pulmonary outCow tract, with severe
cardiac consequences.
FIGURE 3-20 Carbon dioxide (CO ) portal venogram. A, Unsubtracted2
image from wedged hepatic venogram shows CO filling portal vein (curved2
arrow). Density of CO is same as gas in bowel (straight arrow). B, Digital2
subtraction of same frame. Visualization of portal venous system is excellent.
(From Kaufman JA, Lee MJ, editors. Vascular and interventional radiology:
the requisites. St. Louis: Mosby; 2004.)
Mechanical injectors that can be used for CO are not available in the United States. Injections2
must therefore be performed by hand. Scrupulous handling of CO is necessary to prevent2
contamination by less soluble room air. Explosive delivery of gas through the catheter can be
avoided by first purging the ambient liquid in the catheter with a small volume of gas.
Gadolinium chelates were originally developed as contrast agents for magnetic resonance
imaging (MRI). The acute safety proBle of these contrast agents is superior to that of iodinated
contrast, and there appears to be lower nephrotoxicity. There is no cross-sensitivity in patients
with a history of anaphylaxis to iodinated contrast. However, patients with impaired renal
18function (creatinine clearance For this reason, this contrast agent may be most suited for
patients with true anaphylaxis to iodinated contrast and normal or near-normal renal function.
The k-edge of gadolinium is 50 keV, slightly higher than iodine (33 keV). This allows
visualization of gadolinium with current digital subtraction angiographic equipment. Although
the approved doses of most gadolinium-based agents are 0.1 to 0.3 mL/kg, volumes of 40 to
60 mL have been used for many years. Special injection techniques or equipment are not
required for gadolinium-based contrast agents. Digital subtraction angiography is necessary
because the low gadolinium concentration in the available formulations results in weak
opaciBcation of deep vessels. Gadolinium-based contrast agents have been used safely in every
vascular application, including carotid and coronary arteries. These contrast agents are very
expensive compared to nonionic contrast agents and extremely expensive compared to CO .2Arterial Access
The patient should be positioned on the angiographic table in a manner that provides the easiest,
most direct access to the puncture site. Patient comfort is extremely important, but the
angiographer's ability to access the artery, manipulate the catheter, observe the puncture site,
and use the table controls during the procedure are paramount. Also, all tools must be nearby
before beginning so time is not wasted during the procedure looking for something needed
routinely.
There are a few guidelines for selecting an arterial access for a procedure. The area of interest
should be approachable from the access artery. The access artery must be large enough to
accommodate devices needed for the procedure. There should be no critical or fragile organs
between the skin and the artery to be accessed. The puncture should be over bone whenever
possible so the vessel can be compressed against something stable at the end of the procedure.
The pulse should be readily palpable to facilitate the puncture and, more important, the
compression. The vessel to be punctured should be as normal as possible; bad arteries lead to bad
complications. Lastly, the overlying skin should be free of infection and fresh surgical incisions.
Never underestimate the damage that can be caused by needles, guidewires, and catheters in
the arterial system. Strict adherence to technique and respect for the delicacy of the arteries,
especially when diseased, will maximize the safety of the procedure. Excellent guidelines for
19,20diagnostic angiography have been published by the Society of Interventional Radiology.
Common Femoral Artery Access
The common femoral artery (CFA) is the most common access site for angiography. The CFA is
usually near the skin (even in heavy individuals), large enough to accommodate standard
angiographic tools, and easy to compress against the underlying femoral head. Furthermore, the
CFA is contained within the femoral sheath, which helps control peripuncture bleeding.
The majority of CFA punctures are retrograde toward the abdomen (against arterial blood
Cow), as opposed to antegrade toward the leg (in the direction of arterial blood Cow). For all
approaches, the CFA should be accessed over the middle or lower third of the femoral head to
facilitate compression at the termination of the procedure. The artery is localized by palpation or
ultrasound. In large or elderly patients, the inguinal fold cannot be relied on to localize the CFA;
it may hang down over the superBcial femoral artery. A blunt metal instrument placed on the
skin at the anticipated point of access can be Cuoroscoped to determine its relationship to the
femoral head. The entry site in the skin should be 1 to 2 cm lower than the intended entry site
into the artery (for antegrade punctures, make the skin entry the same distance above) to allow
a 45-degree angle of the needle relative to the artery during puncture. The skin and soft tissues
are anesthetized with 1% to 2% lidocaine injection. Using the tip of a #11 scalpel blade, a 5-mm
nick is made on the skin. The skin nick and a subcutaneous tract are then dilated gently with a
straight surgical snap. This facilitates catheter insertion during the procedure and egress of blood
in the event of postprocedural bleeding.
The access needle is held Brmly by the hub in one hand while the skin nick is straddled by the
tips of the second and third Bngers (either one above and one below or one on each side) of the
other hand (Fig. 3-21). The needle is advanced slowly through the nick at a 45-degree angle until
arterial pulsation can be felt transmitted through the needle. The needle is then Brmly thrust
forward until the underlying bone is encountered. The periosteum can be anesthetized with an
additional small amount of lidocaine injected directly through the needle (be sure that bloodcannot be aspirated before injecting). The hub of the needle is slowly withdrawn until blood
spurts out of the hub. A slight “pop” is frequently felt just as the needle tip enters the lumen of
the artery. The Cow of blood should be pulsatile and vigorous from an 18-gauge needle but may
only drip from a 21-gauge needle. When the visible Cow does not correlate with the quality of
the pulse, the needle tip may be partially intramural (“side walled”), under a plaque, in a vein,
or in the orifice of a small branch vessel.
FIGURE 3-21 Technique for localization of arterial pulse during puncture.
(From Kadir S. Diagnostic angiography. Philadelphia: WB Saunders; 1986.)
Once satisfactory Cow is obtained from the needle, an atraumatic guidewire (e.g., 3-J long
taper or Bentson wire) is introduced through the hub. There should not be any resistance to
advancement of the guidewire. If there is resistance, or the guidewire curls as it exits the needle,
the tip may be only partially in the artery, or the guidewire may be being directed against the
wall or under a plaque. When the guidewire will not advance freely, the tip should be inspected
Cuoroscopically. The angle of the needle can be changed slightly to align with the long axis of
the artery. The guidewire is then gently readvanced while under continuous Cuoroscopic
monitoring. When adjusting the needle hub slightly does not correct the problem, remove the
guidewire to check for good blood return through the needle. A small injection of contrast agent
at this point may help resolve the problem, but this should only be done if there is good bloodreturn. Otherwise, there is a risk of injection into the wall of the artery and creation of an
obstructing dissection.
Antegrade access is di3erent than retrograde access in that the direction is toward smaller
peripheral rather than progressively larger central vessels. At the groin, the CFA bifurcates just
below or at the inferior margin of the femoral head, so only a short length of artery may be
available for access. Antegrade punctures can be di0 cult or impossible in obese patients, owing
to excessive adipose tissue over the access site. On occasion, a large pannus can be su0 ciently
retracted with tape to allow an antegrade approach, but often this results in a very steep access.
When performing an antegrade puncture, keep in mind that the superBcial femoral artery (SFA)
origin is medial and anterior to the profunda femoris artery (PFA) origin. A Coppy-tipped 3-J
guidewire should be used because the SFA is larger than the PFA.
Arterial punctures are characterized as double walled (as detailed above) or single walled. In a
single-wall puncture, an open needle is advanced only a few millimeters after the tip touches the
artery just through the anterior wall of the vessel. This creates one hole in the artery, which is
plugged with the catheter during the procedure, thus theoretically decreasing the chance of a
bleeding complication. Single-wall punctures are more di0 cult than double-wall punctures. If the
open needle tip is only partially in the lumen, there may be good blood return, but the guidewire
can enter into the subintimal layer as it exits the needle.
Accessing the nonpalpable artery can be challenging (either due to obstruction, low blood
pressure, or patient obesity). Puncture under ultrasound guidance is an excellent approach in this
situation, eliminating all guesswork. When ultrasound is not readily available, Cuoroscopic
evaluation of the groin may show calciBcation in the CFA. These calciBed vessels can be
punctured under direct Cuoroscopic guidance. Another strategy is to opacify the vessel with
contrast from a catheter placed through a di3erent access site, but this is usually done only when
two catheters are needed, such as before an intervention. Blind puncture over the medial third of
the femoral head may yield success but is the least productive strategy. However, if the femoral
vein is entered during any of these attempts, a guidewire can be inserted. This can then be used
as a guide to direct the needle lateral to the adjacent CFA during fluoroscopy.
Puncture of the postoperative groin requires knowledge of the type and age of the surgery,
particularly if a vascular repair is present. Most angiographers prefer to wait 6 weeks before
access through a recently operated groin, because the area can be very tender and there is a
small concern about damaging the vascular repair. In reality, the artery and graft can be
punctured immediately. Antibiotics are usually not necessary when puncturing a prosthetic graft.
An important potential pitfall is present in the postoperative groin when an onlay graft is
anastomosed to the CFA. This creates a wide “hood,” with the native artery on the bottom and
the graft on the top. During percutaneous access, it can be di0 cult to negotiate out of the native
CFA into the more anterior graft, particularly if the external iliac artery is patent (Fig. 3-22). In
addition, scarring in the groin may make it hard to introduce catheters. Overdilation of the tract
by at least 1 French size and a stiff guidewire may be required to introduce even a 5F catheter.FIGURE 3-22 Puncture of groin after aortofemoral bypass. 1, Guidewire is
directed into native vessel by access needle. Note anterior relationship of
graft (arrow) to native artery. 2, Short, angled catheter is used to redirect
guidewire into graft. (From Kaufman JA, Lee MJ, editors. Vascular and
interventional radiology: the requisites. St. Louis: Mosby; 2004.)
Complications from CFA punctures are related primarily to vascular trauma during the
procedure and lack of hemostasis afterward (Table 3-5). Attention to detail and a gentle touch
help avoid most intraprocedural complications. Arterial dissections that occur during retrograde
access are frequently subclinical because antegrade blood Cow tends to compress the false lumen.
Thrombosis is unusual unless a tight stenosis or very low Cow is present; anticoagulation with
heparin during the procedure is warranted in this situation.
TABLE 3-5
Complications of Common Femoral Artery Puncture
Complication Acceptable Incidence
Hematoma (requiring transfusion, surgery, or delayed discharge)
Occlusion
Pseudoaneurysm
Arteriovenous fistula
The riskiest part of invasive vascular imaging is actually when the catheter has been removed,
when arterial bleeding may occur. Patients who receive heparin during a procedure should have
the activated coagulation time checked before removing the catheter or sheath. Protamine sulfate
(10 mg/1000 units heparin still active) can be given slowly to correct a prolonged coagulationtime. Patients with an abnormal INR (>1.5) can be given 2 units of fresh frozen plasma during
the compression. The person performing manual compression must know the location of the
catheter entry site in the artery relative to the skin nick and the quality of the pulse before the
procedure. The pulse should be identiBed with certainty before the catheter is removed. Occlusive
pressure is maintained for 1 to 2 minutes, after which it is reduced gradually to allow some
prograde blood Cow (usually this results in a palpable thrill or slight pulse under the Bnger tips).
The occlusive pressure should be limited to 1 minute when compressing a graft, because the
likelihood of thrombosis is higher than with a native vessel. After 15 minutes, only light pressure
should be required. Should bleeding resume, pressure is reapplied and the 15-minute clock
restarted. When a hematoma begins to form during compression, the pressure is either
inadequate or being applied in the wrong place. Patients with heavily calciBed vessels, with
systolic blood pressure greater than 200 mmHg, or who are systemically anticoagulated are at
greatest risk of bleeding and may require prolonged compressions. A sandbag should never be
substituted for manual compression, because it is not only useless but also can hide development
of a hematoma. Patients who undergo manual compression of the puncture should remain in bed
with the head elevated to 30 degrees and with the leg immobilized for 6 hours.
There are several alternatives and adjuncts to manual compression of arteries, such as arterial
21closure devices, clamps, and hemostatic pads. One major advantage of closure devices is that
the patient may ambulate much sooner than after manual compression. The closure device
strategies include remote suturing of the vessel, deposition of a hemostatic plug or procoagulant
gel over the surface of the vessel, placement of an external clip on the surface of the artery, and
applying a patch inside the lumen. A Bbrotic reaction in the soft tissues may be associated with
plug and patch devices. For some devices, the size of the hole in the artery wall must be
increased to introduce the closure system. All these devices require training for proper use and
are extremely useful in patients at risk for postcompression bleeding, such as those on
anticoagulant therapy, with low platelets, or who cannot remain still for 6 hours. These devices
21fail to achieve hemostasis or require additional manual compression in 5% to 10% of patients.
Closure devices should not be used if there is any question of bacterial or fungal contamination
of the access site. Infection of the soft tissues or arterial wall has been reported, as has
pseudoaneurysm formation, bleeding, and arterial occlusion. An alternative strategy is to
substitute an external clamp for manual compression. These patients must remain on bed rest for
at least the same length of time as for manual compression.
Axillary/High Brachial Artery Access
The upper extremity approach to arterial access is an alternative to the CFA in patients with
absent femoral pulses or groin conditions that preclude safe access or when an upper extremity
intervention is anticipated (Fig. 3-23). This approach is a secondary access because of the small
(0.5%) risk of stroke (related to the catheter crossing the origins of one or more great vessels)
and peripheral upper extremity nerve injury (due to nerve compression by a hematoma in the
22medial brachial fascial compartment). The upper extremity arteries tend to be smaller and
more prone to spasm than the CFA, which limits the size of devices that can be introduced. In
general, the axillary and high brachial arteries can accommodate up to a 7F sheath without
di0 culty. Patients with uncorrected coagulopathy, uncontrolled hypertension, and morbid
23obesity are contraindicated for axillary/brachial artery access. In addition, because the arm
must be placed over and behind the patient's head for the duration of the angiogram, individualswith severe arthritis or other shoulder pathology may not be able to tolerate an upper extremity
access. The overall incidence of complications with axillary and high brachial artery punctures is
higher than that of CFA puncture.
FIGURE 3-23 High brachial artery puncture of left arm. Artery is entered
lateral to pectoral fold. (From Kadir S. Diagnostic angiography. Philadelphia:
WB Saunders; 1986.)
For procedures involving imaging of the abdominal aorta or the lower extremities, the left arm
should be used so the catheter crosses only one cerebral artery (the left vertebral artery). For
imaging the ascending thoracic aorta or selecting the cerebral vessels from the axillary approach,
the right arm provides the best access. Before the procedure, upper extremity pulses should be
palpated and blood pressures in both arms measured. A blood pressure di3erential of more than
10 to 20 mmHg suggests the presence of stenosis in the a3ected extremity, and access via the
opposite arm should be considered.
The patient should be positioned on the angiographic table so the arm is abducted 90 degrees,
with the elbow Cexed and the hand placed under the back of the head. The arm should be
supported with pillows or soft towels. A digital pulse oximeter on the side of the arterial access
helps monitor perfusion of the extremity during the case. The axillary artery is located in the
axilla and as it crosses the lateral edge of the pectoralis major muscle to become the brachialartery. Many angiographers prefer to access the high brachial artery where it lies against the
humerus, rather than the axillary artery proper, because this site is easier to compress. The skin
overlying the artery is anesthetized, but deep anesthesia should be avoided to prevent
inadvertent nerve block (a confusing situation because nerve compression is a potential
complication of the procedure). After making the skin nick and spreading the soft tissues, the
arterial puncture is performed with the following modiBcations. The humerus is superior and
posterior to the high brachial artery (not directly posterior like the femoral head in relation to
the CFA). The needle tip should be angled slightly toward the patient's head to hit the artery. A
good initial guidewire for axillary or brachial artery puncture is a Coppy 3-J to prevent
accidental selection of the vertebral artery and other branch vessels. Many angiographers
routinely use ultrasound guidance and microaccess needles for this access.
After the procedure, the arm should be immobilized in a sling for 6 hours, with the patient's
back elevated in bed at least 30 degrees. Periodic pulse, access site, and neurologic examinations
are mandatory during the 6-hour recovery period. Bleeding at the puncture site can result in
compression of adjacent nerves, with ischemic damage. Development of a hematoma at the
access site or weakness, paresthesias, or sensory changes in the hand require urgent evaluation
for possible surgical decompression of the hematoma.
Additional techniques used in patients who have shoulder pathology or speciBc anatomic
considerations (e.g., inability to bend the elbow) may have upper extremity arterial access from
a low brachial artery or radial artery approach. These approaches also have risk and are
mentioned here for completeness. In such instances, the patient may keep the arm straight and
avoid the discomfort of the “hand behind the head” or elbow Cexion (see “Unusual Arterial
Access” later in this chapter).
Translumbar Aortic Access
The translumbar approach to the aorta (TLA) seems like a crude and dangerous approach to
24angiography but is actually an ancient (in angiographic terms), simple, and safe access. The
aorta is a large structure with a constant position, so it is usually easy to locate. The puncture is
guided Cuoroscopically using bony landmarks, allowing successful access in most cases. The main
disadvantages of direct aortic puncture are that selective angiography (other than the cerebral
vessels) is challenging, and the patient must remain in the prone position for the examination.
This access is therefore usually restricted to aortic injections in patients who can lie on their
stomachs for 1 to 2 hours. The chief complication of translumbar aortography is a symptomatic
retroperitoneal hematoma. Virtually all patients have a small self-contained psoas hematoma (up
25to a half unit of blood), but fewer than 1% are symptomatic. Very rarely, the pleural space
may be entered, resulting in a hemopneumothorax. Visceral artery injury due to the needle has
also been reported. Contraindications to TLA access include uncontrolled hypertension,
coagulopathy, known supraceliac aortic aneurysm, severe lumbar scoliosis, and dense
circumferential aortic calcification.
There are two types of TLA puncture: high (entry at the inferior end plate of the T12 vertebral
body) and low (entry at the inferior end plate of L3) (Fig. 3-24). The high approach is used most
often because the low puncture is impossible in patients with infrarenal aortic occlusion (i.e., the
typical TLA patient) and unwise in the presence of an infrarenal abdominal aortic aneurysm.
With the patient prone, the T12 vertebral body and the left iliac crest are localized
Cuoroscopically. For a high access, the skin is anesthetized on the left at a point roughly midwaybetween the lumbar spinous processes and the Cank and several centimeters below the 12th rib.
For a low access, the skin entry site is midway between the iliac crest and the 12th rib. If the skin
nick is too medial, approach to the aorta will be blocked by the vertebral body. A lateral access
may result in puncture of the kidney or inability to reach the aorta with the needle. Deep
anesthesia can be delivered with a 20-gauge spinal needle, but the aorta is rarely reached in
normal adults. Access kits designed for TLA usually include a long 18-gauge needle, with
preloaded coaxial TeCon dilators. For a high access, the needle is advanced under Cuoroscopy
medially and cephalad toward the inferior end plate of T12. For a low access, a more horizontal
approach to the inferior end plate of L3 is used. If the vertebral body is encountered, the needle
is withdrawn several centimeters, the angle adjusted accordingly, and the needle readvanced.
Passing through the psoas muscle fascia can be uncomfortable for the patient. DeCection of
aortic calciBcation by the needle may be visible Cuoroscopically, or a transmitted aortic
pulsation may be felt through the needle. At this point, the needle is Brmly advanced forward a
centimeter (but not across the midline). The stylet is removed, conBrming blood return before
introduction of a guidewire. In almost all instances, the natural direction of the guidewire will be
cephalad. A 0.038-inch guidewire is recommended to minimize kinking in the retroperitoneal
tissues during catheter exchanges. Insertion of a long 5F sheath allows catheter exchanges if
necessary. Reversal of direction of the catheter can be accomplished if necessary by pulling a
pigtail catheter or Simmons 1 catheter to the edge of the sheath, thus directing a guidewire into
the distal abdominal aorta.FIGURE 3-24 Translumbar puncture of abdominal aorta. A, Cross-sectional
diagram demonstrates anterior redirection of needle away from vertebral
body toward aorta. B, Two sites for puncture of aorta are at T12-L1
interspace (high) and L2-L3 interspace (low). (From Kim D, Orron DE.
Peripheral vascular imaging and intervention. St. Louis: Mosby; 1992.)
The best part of a TLA access is the compression: at the end of the procedure as the patient is
rolled from the stomach to the back onto a stretcher, simply pull out the sheath. Patients
commonly experience a mild backache due to accumulation of a small retroperitoneal hematoma,
but otherwise should be asymptomatic. The blood pressure and vital signs should be checked
frequently for several hours (and remain stable). Patients can ambulate after 4 to 6 hours of bed
rest.
Unusual Arterial Access
Almost any artery in the body can be accessed percutaneously but not always safely. The radial
artery can accommodate long catheters that can be advanced retrograde into the thoracic26aorta. The overall complication rate is low, and bed rest is not required after compression.
Patients should have a normal Allen test before catheterization, because radial artery occlusion
occurs in a small percentage of cases.
The popliteal artery can be accessed in the popliteal space using ultrasound guidance. The
usual indication for this access is an intervention in the SFA and embolization of a distal limb
lesion. Popliteal artery access is rare for diagnostic procedures. With the patient in the prone
position, the popliteal artery is accessed with a microaccess needle and ultrasound guidance in a
retrograde or antegrade direction as determined by the type of procedure. The popliteal vein,
which lies superBcial to the artery when the patient is in the prone position, can be avoided by
27using ultrasound guidance.
Venous Access
Percutaneous access of deep venous structures differs from arterial access in that the veins cannot
be palpated. SuperBcial anatomy, anatomic relationships to palpable arterial or bony structures,
or imaging with ultrasound or Cuoroscopy are the major localization techniques. With the
exception of femoral vein punctures, image guidance techniques are used for most venous
28,29punctures.
Veins are forgiving structures with soft pliable walls and low or even negative ambient
intraluminal pressures. Large catheters and devices are readily accommodated through most
percutaneous central venous access sites, with satisfactory hemostasis at the end of the
procedure. Compared to arterial punctures, primary complications associated with deep venous
punctures are thrombosis, injury to adjacent structures (e.g., lung), and rarely, air embolism
30(Table 3-6). Clinically important hematomas are rare but can occur in coagulopathic patients,
especially in the presence of high central venous pressures.
TABLE 3-6
Complications of Central Venous Punctures
Complication Acceptable Incidence
Pneumothorax*
Hemothorax*
Air embolism*
Hematoma
Perforation of vein
Thrombosis of puncture site (symptomatic)
Arterial injury
*Jugular and thoracic veins only.
Common Femoral Vein Access
The common femoral vein (CFV) is most often accessed over the femoral head, superior to the
junction with the deep (profunda) femoral vein and saphenous vein. This segment of vein issimilar to the CFA in that it is relatively large, constant in position, and contained within the
fascia of the femoral sheath. The vein lies medial and deep to the palpable CFA pulse. To access
the CFV, localize the CFA and then anesthetize the skin just medial to the pulse. The skin nick
should be slightly lower than would be used for arterial puncture, because the goal is to enter the
vein over the lower third of the femoral head. A sharp, open needle (without a stylet) is used,
and suction is applied to the hub as the needle is advanced. Blood is aspirated when the needle
enters the vessel. Continuous localization of the arterial pulse with Bngers of the other hand
while advancing the needle prevents inadvertent arterial puncture. If the underlying femoral
head is reached without a blood return, slowly withdraw the needle while maintaining suction.
Remove the Bngers over the femoral pulse, because these can compress the adjacent vein. Vary
the angle of the needle slightly with each pass if no blood return is obtained; the more lateral the
trajectory, the higher the risk of arterial puncture. The femoral vein can be accessed in both an
antegrade (toward the head) or retrograde (toward the foot) direction, depending on the needs
of the procedure. Di0 cult punctures can be performed with continuous ultrasound guidance.
Femoral venous punctures for diagnostic procedures require only 5 to 10 minutes of compression.
Interventional procedures using large sheaths in anticoagulated patients require longer
compression times.
Internal Jugular Vein Access
The internal jugular vein (IJV) is a common access for many diagnostic and interventional
procedures. The right IJV is the optimal access for insertion of tunneled catheters. The traditional
approach to IJV access is based on anatomic landmarks, with a posterior, middle, or anterior
approach. Access with ultrasound guidance is the preferred method by interventional
radiologists. Puncture of the carotid artery and pneumothorax, the major complications of blind
IJV access, can be almost eliminated by using ultrasound guidance.
The IJVs should be checked with ultrasound for location relative to the carotid arteries,
compressibility, and change in size with respiration and cardiac cycle (indicating central
28patency) before Bnal preparations. The patient should be placed in Trendelenburg position or
with the legs elevated on pillows to dilate the IJVs. Microaccess needles are optimal for
ultrasound-guided IJV puncture.
The access site for an IJV access should be in the midportion of the neck for diagnostic and
interventional procedures, and lower and posterior for tunneled venous catheters. The right IJV
is the desirable vein for diagnostic or interventional venous procedures involving the thorax or
abdomen, because it provides straight-line access to the superior and inferior venae cavae (SVC,
IVC). The access needle is advanced under ultrasound guidance until it is seen to enter the vein
or blood can be aspirated (Fig. 3-25). Aspiration of air may indicate transgression of the pleural
cavity or (more often) that the syringe is not attached Brmly to the needle. After achieving
venous access, the guidewire should pass easily to the right atrium and often into the IVC. If
accidental carotid puncture is suspected, either pull out everything or insert the 3F inner dilator
from the microaccess kit over the 0.018-inch guidewire and inject a small amount of contrast
agent to confirm the catheter location.FIGURE 3-25 Ultrasound-guided puncture of internal jugular vein at base of
neck. A, Axial view of vein shows microaccess needle (arrow) in
sternocleidomastoid muscle. B, Needle tip (arrow) is in vein. (From Kaufman
JA, Lee MJ, editors. Vascular and interventional radiology: the requisites. St.
Louis: Mosby; 2004.)
Percutaneous access via the IJV has a very low overall complication rate (see Table 3-6).
Puncture-related thrombosis is less common in the IJV than most other venous access sites.
However, a unique and potentially lethal risk of IJV (as well as subclavian vein) access is
introduction of air (air embolism) through an open catheter, dilator, or sheath (particularly the
peel-away type) into the central venous circulation if the patient takes a breath at the wrong
moment. A small amount of air introduced into the central venous system is harmless, but a large
amount (20-30 mL) can obstruct the pulmonary outCow tract. To minimize the risk, the patient
should be instructed to perform a Valsalva maneuver or hum whenever a needle, catheter, or
sheath is open to room air. Placing the patient in Trendelenburg position also helps decrease the
chance of air embolism.
Should an air embolism occur during a procedure, Brst check the patient's vital signs for a drop
in blood pressure or oxygen saturation. The patient may complain of chest pain or pressure.
Stable patients can be observed for several minutes as air is absorbed. The air can sometimes be
seen in pulmonary outCow tract with Cuoroscopy. An unstable patient should be turned left side
down to trap air in the capacious right atrium. In severe cases, a catheter can be introduced into
the right atrium to aspirate the air.
After catheter removal, jugular veins can be compressed with the back of the patient's bed
elevated. The patient should be instructed to perform a Valsalva maneuver during catheter
removal, and occlusive pressure should be applied over the IJV as the catheter is removed. The
duration of compression is usually 5 to 10 minutes. Keep in mind that air embolism through thesubcutaneous tract can occur in thin patients.
Subclavian Vein Access
Percutaneous subclavian vein access has traditionally been based on superBcial landmarks. With
this approach, access is achieved in 90% to 95% of attempts, but pneumothorax and subclavian
artery puncture also occur in 3% to 5%. With image-guided puncture, complications are reduced
29to less than 1%, with a 100% success rate.
The safest place to access the subclavian vein is over the anterior aspect of the Brst rib, lateral
to the clavicle. The vein should not be accessed under the clavicle, especially when placing
longterm central venous catheters, because this may lead to compression and fracture of the catheter
31(“pinch-o3 syndrome”) between the clavicle and Brst rib. The subclavian vein is inferior and
anterior to the subclavian artery over the Brst rib, so arterial puncture is less common in this
location. The presence of underlying bone minimizes the risk of pneumothorax during puncture.
At the lateral margin of the Brst rib, the vessel becomes the axillary vein, which is best accessed
over the anterior portion of the second rib for the same reasons listed earlier.
Access of the subclavian vein can be guided with ultrasound or Cuoroscopy. The disadvantage
of ultrasonography is that the structures below the vein (rib and lung) may be di0 cult to
visualize, and central venous patency cannot be assessed. The technique is virtually identical to
that used for the jugular veins. The advantage of ultrasonography is that contrast medium is not
necessary, so radiation exposure to the operator and patient is minimized. For
Cuoroscopicguided puncture, an upper extremity venogram can be performed by injection of 10 to 20 mL of
contrast material through a vein in the hand or forearm. This allows exact localization of the
subclavian vein as it crosses the ribs and confirms patency of the central venous system. Puncture
can then be performed with carefully coned-down Cuoroscopy over the needle tip. A microaccess
needle is advanced under direct visualization until blood is aspirated or the tip touches the
anterior surface of the first rib.
Translumbar Inferior Vena Cava Access
Direct access to the IVC is used primarily for placement of long-term central venous access
32devices. Diagnostic central venous procedures can almost always be performed from a
peripheral approach. This access is similar in technique and materials to a low TLA, but the
approach is from the right rather than the left.
Previous studies such as computed tomography (CT) scans and magnetic resonance imaging
(MRI) should be reviewed before the procedure to determine IVC anatomy, particularly in a
patient with an abdominal aortic aneurysm or retroperitoneal mass. When Brst performing this
procedure, it may be helpful to place a 5F pigtail catheter into the IVC from a femoral approach
to localize the IVC during puncture.
The patient is placed either prone or in left lateral decubitus position, with a small towel roll
under the left Cank to straighten the spine. A translumbar aortography needle/sheath system is
inserted at a point approximately 10 cm to the right of the spinous process and just above the
right iliac crest. The needle is advanced at a 45-degree angle cephalad toward the top of the L3
vertebral body until bone is encountered. The needle is then withdrawn, angled more anteriorly,
and readvanced so it passes just anterior to the vertebral body. If a catheter has been placed in
the IVC, it can be used as a target for puncture.
Puncture of an arterial structure is usually inconsequential unless the patient is coagulopathic;however, these patients should be observed with the same postprocedural protocol used for TLA
punctures. Many patients have transient pain radiating to the right leg during the procedure. If
pain is severe, the needle should be reinserted from a more lateral position to avoid the psoas
muscle.
Imaging
An essential element of angiography is the permanent recording of the contrast injection. Simple
observation with Cuoroscopy is not acceptable (no images = no diagnosis). Historically, there
have been two basic modes of recording angiographic images: Blm-screen and digital
angiography. The former is archaic. The latter is almost always displayed as a subtracted image
33(digital subtraction angiography [DSA]). Cineradiography as used in cardiac catheterization
has no role in noncardiac applications.
DSA is the most widely used angiographic technique in current practice (Fig. 3-26). The
original clinical application of DSA was a large, rapid venous injection of contrast agent, with
acquisition of digitally subtracted images timed to record arterial opaciBcation by the bolus
(IV34DSA). This was an unsatisfactory application of a brilliant innovation because of
unpredictable venous opaciBcation due to variations in cardiac output, poor resolution of the
weakly opaciBed arteries, inability to selectively inject arteries, and motion artifacts. Direct
intraarterial injection of contrast medium, as used with Blm-screen angiography, rapidly
replaced IV-DSA. Digital angiography still has lower resolution than Blm-screen, but the
extremely rapid acquisition of images and processing (the subtraction is performed
instantaneously and displayed on a monitor) as well as the ability to manipulate the image
appearance online compensate for poor opaciBcation, negating this disadvantage. The
interchange between Cuoroscopic and DSA modes is electronic and almost instantaneous rather
than mechanical and slow. Images can be viewed in either subtracted or unsubtracted (raw)
states. Filming can be as rapid as 30 frames per second with some angiographic equipment, with
continuous acquisition while moving the angiographic table (bolus chase) or the tube (rotational
angiography). Newer units can construct CT-like images and three-dimensional (3D) models from
rotational angiographic data (cone-beam CT), a useful tool during complex diagnostic and
interventional procedures (Fig 3-27). Lower-contrast concentrations can be used (30%-50% less
iodine than the older Blm-screen angiography) without altering injection rates. The exquisite
sensitivity of this technique allows use of negative contrast agents such as CO for angiography.2
The limitations of DSA in addition to lower resolution include subtraction artifacts from
involuntary motion such as bowel peristalsis, respiration, and cardiac pulsation and a tendency
to “shoot Brst and ask questions later” (collect lots of images quickly, with only superBcial
review during the procedure).FIGURE 3-26 Digital subtraction angiography. A, Unsubtracted image of
injection in inferior vena cava. Note that contrast in vein is dense (white), as
are bones. Gas in bowel is black. B, Subtracted view of same image.
Stationary bones and background tissues are now absent, greatly increasing
visibility of contrast in vein. Because there is bowel peristalsis, gas artifact is
seen in abdomen. (From Kaufman JA, Lee MJ, editors. Vascular and
interventional radiology: the requisites. St. Louis: Mosby; 2004.)FIGURE 3-27 Postprocessed rotational digital subtraction angiogram (DSA)
with a flat-panel image intensifier. A, Conventional DSA of celiac artery
injection. Note medial branch of left hepatic artery (arrow) to segment 4 of
liver. B, Maximum intensity projection (MIP) image from a rotational selective
angiogram of segment 4 branch (arrow). (From Kaufman JA, Lee MJ editors.
Vascular and interventional radiology: the requisites. 2nd ed. Philadelphia:
Elsevier; 2013.)
Whether using Blm-screen or DSA, it is necessary to determine positioning and image
acquisition rates for each injection. Patient positioning has been loosely standardized for most
angiograms based on the anatomy under evaluation and the empiricism that two di3erent views
of the same vascular structure are necessary for evaluation of most pathologic processes (one
view = no view) (Fig. 3-28). Similarly, contrast injection and image acquisition rates have been
developed for di3erent studies based on expected Cow rates and pathologic processes. Individual
variations in positioning, injection rates, and Blming are frequently necessary because Cow may
be slower or faster than anticipated or the pathologic process may be visible only on delayed
images. In general, images should be acquired faster during the arterial phase and then more
slowly to follow the capillary and venous phases. Large vascular spaces such as aortic aneurysms
require longer injections and large volumes of contrast (not faster injection rates) to be
adequately opaciBed. Large vascular beds (e.g., lower extremities) require long injections at a
lower rate to ensure complete opaciBcation, and rapidly Cowing blood may require both high
flow rates and large volumes (e.g., thoracic aortogram in a young hyperdynamic patient).FIGURE 3-28 Evaluation of most vascular structures requires imaging in at
least two views. A, Screen-film pelvic angiogram in anteroposterior
projection. No obvious lesion present on right, but patient had slightly
diminished right femoral pulse. B, Digital subtraction view of right external
iliac artery in right posterior oblique projection. Eccentric stenosis (arrow) is
now readily visible. Note that internal iliac artery origin is also clearly seen.
Intravascular Ultrasonography
Intravascular ultrasonography is an invasive technology that combines features of noninvasive
35imaging. By placing a probe on the end of a catheter (usually 4F-9F), direct access to the
vascular lumen can be obtained (Fig. 3-29). A hemostatic sheath is necessary to allow safe
introduction of a probe. Rather than look from the outside in, intravascular ultrasonography is
used to look from inside out (Fig. 3-30). This technique is a useful adjunct to conventional
angiography when evaluating intraluminal processes such as dissections or vessel wall
abnormalities such as eccentric stenoses that are di0 cult to visualize on an angiogram (Fig.
331). Precise luminal diameter measurements can be obtained, and stenoses can be localized. This
may be particularly useful during complex interventions. The arterial wall can also be assessed
for subtle changes of atherosclerosis, although the clinical utility of this information remains to
be determined. The limitations of the technique are the expense of the additional equipment, the
inability to look forward with the catheter (most designs are based on a rotating transducer that
can image only in the axial plane), the small Beld of view when compared with external probes,
and the limited penetration of smaller probes.FIGURE 3-29 Intravascular ultrasound probe (9F, 9 MHz). Transducer
(arrow) is located proximal to tip of catheter. Smaller-diameter probes that
can be inserted over a guidewire are readily available. (From Kaufman JA,
Lee MJ, editors. Vascular and interventional radiology: the requisites. St.
Louis: Mosby; 2004.)FIGURE 3-30 Normal intravascular ultrasound (IVUS) images of popliteal
artery. A 6F probe (12.5 MHz) is visible in center of vessel. Echogenic
intima, hypoechoic media, and echogenic media are clearly visualized
(arrow). (From Kaufman JA, Lee MJ, editors. Vascular and interventional
radiology: the requisites. St. Louis: Mosby; 2004.)
FIGURE 3-31 Intravascular ultrasound image of eccentric external iliac
artery stenoses. A, Oblique digital subtraction angiogram of right external
iliac artery shows several areas (arrows) of decreased contrast density
consistent with bulky calcified plaque. B, Intravascular ultrasound image (7F,
12 MHz) of same vessel shows one of the calcified eccentric stenoses
(arrow). (From Kaufman JA, Lee MJ, editors. Vascular and interventional
radiology: the requisites. St. Louis: Mosby; 2004.)
Key Points
• Invasive vascular diagnosis remains an essential competency in image-guided
intervention.• Information is power; the more you have before the procedure, the better the
outcomes.
• The interventionalist's responsibility includes providing preprocedural consultation
and postprocedure care as well as performing the procedure.
• Vascular access selection requires consideration of the target vascular bed, devices
that will be used, and the ability to obtain hemostasis at the end of the procedure.
• Imaging (the blood vessels injected and images collected) should match the vascular
anatomy, physiology, and clinical scenario.
▸ Suggested Readings
Kandarpa, K, Machan, L. Handbook of interventional radiologic procedures, 4th ed. Philadelphia:
Wolters Kluwer/Lippincott Williams & Wilkins; 2011.
Kaufman, JA, Lee, MJ. Interventional radiology: the requisites, 2nd ed. Philadelphia: Elsevier; 2013.
Valji, K. Vascular and interventional radiology, 2nd ed. Philadelphia: Saunders/Elsevier; 2006.
Waybill, PN, Brown, DB. Patient care in vascular and interventional radiology, 2nd ed. Fairfax: SIR
Press; 2010.
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32. Rajan, DK, Croteau, DL, Sturza, SG, et al. Translumbar placement of inferior vena caval
catheters: a solution for challenging hemodialysis access. RadioGraphics. 1998; 18:1155–
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33. Mistretta, CA. Relative characteristics of MR angiography and competing vascular
imaging modalities. J Magn Reson Imaging. 1993; 3:685–698.
34. Katzen, BT. Current status of digital angiography in vascular imaging. Radiol Clin North
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35. Manninen, HI, Rasanen, H. Intravascular ultrasound in interventional radiology. Eur
Radiol. 2000; 10:1754–1762.S E C T I O N T H R E E
Instruments of
Intervention
OUTLINE
Chapter 4: Diagnostic Catheters and Guidewires
Chapter 5: Balloon Catheters
Chapter 6: Stents
Chapter 7: Thrombectomy Devices
Chapter 8: Embolic Protection Devices
Chapter 9: Atherectomy Devices
Chapter 10: Embolization Agents
Chapter 11: Aortic Stent-Grafts
Chapter 12: Inferior Vena Cava Filters
Chapter 13: Endovascular Laser Therapy
Chapter 14: Intellectual Property Management





C H A P T E R 4
Diagnostic Catheters and
Guidewires
Curtis W. Bakal and Sebastian Flacke
The basic principles of vascular access and catheter guidewire manipulation for
selective and superselective angiography were described over a half century ago.
Continued re nements in early techniques and equipment have facilitated the
myriad sophisticated interventions that are considered current standard practice. The
basic principles of diagnostic catheter and guidewire design and manipulation are
nearly universal, and an understanding of these fundamental concepts and
techniques is crucial to successful contemporary interventional practice.
Puncture Needles
The rst percutaneous arteriograms were performed by direct needle puncture of the
target vessel. In 1927, Egas Moniz developed the technique for cerebral angiography
by direct puncture of the carotid artery; he is considered the father of cerebral
1angiography. Dos Santos and colleagues described a technique for nonselective
aortography in which long needles were inserted via the translumbar approach
under the guidance of surface anatomic landmarks because ) uoroscopy was not yet
2,3available. Early selective angiography was performed via direct cutdown and
catheter insertion. The Seldinger technique for femoral access, rst reported in 1953,
4enabled simple and safe ) ush aortography. Seldinger's U-shaped catheter extended
application of his technique to selective catheterization of rst-order aortic
5branches. However, the use of long 16-gauge sheathed needles for direct aortic
access continued up to the early 1990s for cases in which femoral artery access was
unavailable because the high brachial or axillary artery approach was cumbersome
6and had higher rates of signi cant complications. With the advent of newer
4French (4F) catheters, brachial artery access became safer, and translumbar
aortography soon became obsolete.
Needle gauges are derived from wire-gauging standards rst used in England
during the late 1880s (e.g., Stubbs or Birmingham Iron Wire Gauge system). Needle
diameter (inches, estimated) = 1/gauge. Smaller gauges indicate larger diameters.

7The gauge number (G) always indicates the outer diameter of a needle. French (F)
size refers to the diameter of a catheter in French units (3F = 0.97 mm = 0.038
inch). Larger French sizes indicate wider catheters. Catheter and dilator sizes are
designated by the outer diameter, whereas sheaths are typically designated by their
inner lumen size, that is, the maximum catheter diameter capacity (e.g., a 6F sheath
accepts a 6F catheter). Typically, the outer diameter of a vascular sheath is 1.5F to
2F larger than the inner lumen.
Here are some conversions: A 16G needle has an outer diameter of 1.65 mm,
corresponding to the outer diameter of a 5F catheter; a 20G needle has an outer
diameter of 0.97 mm, corresponding to 3F.
Brachial access from the left (rather than right) side is normally favored. The
leftsided approach should produce fewer neurologic complications because the carotid
arteries are not in the catheter-wire path; manipulation of the catheter in the
descending thoracic and abdominal aorta and its branches is also easier, especially in
older patients with ectatic aortic arches. Direct aortic access via translumbar
techniques for embolization of endoleaks and for direct vena cava dialysis and
catheter placement has revitalized the use of translumbar access needles as
8,9interventional rather than diagnostic tools. The needles are also used to provide
10,11transhepatic access for long-term central venous access. Early arteriography
used direct needle puncture techniques for both vascular access and injection. After
initial needle placement, the sharp puncture stylet would be removed, and if
vigorous arterial ) ashback was con rmed, the needle hub would be tipped
downward to approximate the axis of the artery, and a blunt stylet inserted to
advance the needle into the vessel. The needle was subsequently used for
12nonselective hand injection. These blunt obturators are packaged in some
contemporary puncture needle kits, a testament to primordial diagnostic
angiography.
Seldinger's original technique involves the use of a hollow nonbeveled thin-walled
cannula that accepts a sharp stylet for puncture. The classic 18G needle will accept a
0.038 inch guidewire, whereas the 19G needle will allow a 0.035 inch guidewire.
Because 18G puncture needles have larger cross-sectional diameters than 4F
diagnostic catheters do, they have been supplanted by 19G needles as the standard
needle in many interventional radiology suites. The hub end of such needles is
typically ) anged, which assists in stabilizing it during access. The back end is
funneled to direct the guidewire into the trailing portion of the needle. The
doublewall puncture is made through the super cial anterior and deeper posterior vessel
walls. After the stylet is removed, the needle is pulled back through the deep arterial
wall into the lumen; when pulsatile ) ashback is returned, the guidewire is advanced
4into the vessel.



Many interventional radiologists now favor single-wall puncture, a variant of
Seldinger's original technique. Needles used for this technique have a hollow
nonstylet needle with a beveled cutting edge; the artery is entered on a forward pass
through the anterior arterial wall into the lumen. Although these two techniques are
often used interchangeably and according to individual operator preference, speci c
13situations may favor the single-wall technique. Posterior wall puncture is
generally avoided in patients with coagulopathy or those in whom lysis is planned
because it increases the risk of bleeding. Single-wall cutting needles also facilitate
access through brotic postoperative groins. They are favored by many for femoral
venous puncture before dilation for placement of inferior vena cava lters to avoid
accidental double puncture of the femoral vein and artery. (The vein may lie
partially behind the artery with a low puncture.) As a cautionary note, because the
single-wall needle tip is beveled, it can be both luminal and intramural and return
pulsatile ) ow. Advancing the guidewire in this circumstance may initiate subintimal
dissection. Dissection can also occur with good luminal position of any needle tip
because the rmly held stiC needle cannot back away from a constrained advancing
wire tip. Guidewire-related dissections can be diD cult to recognize and thus may
involve relatively long sections of the punctured artery (Fig. e4-1).FIGURE E4-1 A, Iatrogenic dissection of right external iliac
artery related to guidewire advancement from puncture site.
Right femoral puncture was abandoned, and a left femoral
puncture was subsequently performed. Patient had a decreased
right femoral pulse. B, Dissection was treated with two
selfexpanding stents to restore flow and pulse strength.
The Potts or Potts-Cournand needles are also variants of the original Seldinger
design and are favored by neuroradiologists. This needle family was originally
designed for direct carotid artery puncture. The outer cannula has a short bevel to

minimize trauma during anterior wall entry, and its trailing end protrudes slightly
into the hub to minimize the chance of thrombus formation or air trapping. The solid
or hollow stylet is also beveled and is thought to facilitate entry into mobile neck
arteries during direct puncture. Modi cations of this needle type have eliminated the
trailing protrusion by substituting a funneled hub for easier insertion of the
guidewire.
The use of coaxial micropuncture systems for vascular access has increased in
recent years; these systems are based on longer devices originally designed for safe
organ access for nephrostomy or biliary drainage. The initial puncture is thought to
be relatively error tolerant because it is performed with a 21G (rather than a
standard 18G or 19G) needle. After passage of a stiC 0.018-inch guidewire, the
needle is exchanged for coaxial Te) on dilators that allow conversion to a 4F or 5F
system and subsequent passage of a 0.035-inch standard guidewire. This technique is
especially favored for perceived diD cult access situations in which multiple passes
might leave an abandoned needle puncture (e.g., antegrade femoral puncture,
thrombolysis), for dialysis access interventions, for ultrasound-guided punctures
through anatomically sensitive regions (e.g., internal jugular vein), and for early
resident or fellowship training. Although design improvements have been made, at
times these microsystems may be extremely diD cult to use in scarred groins or obese
patients; during upsizing, the 0.018-inch guidewire support for antegrade passage of
the dilator may be insufficient.
Microsystems or large butter) y-type intravenous (IV) needles are often used for
access in small children.
Single-wall and double-wall puncture systems engineered to minimize operator
exposure to pulsatile blood during vascular access have become popular. These
systems consist of a vascular entry needle attached to a blood containment element,
typically a short length of transparent valved tubing attached to the hub via a side
port. The needle hub also contains a one-way valve that precludes back) ow of ) uid
but allows antegrade passage of a guidewire. Flashback into the clear containment
tubing signals lumen entry. The ability to hand-inject contrast material around a
guidewire via the side port has helped popularize this type of needle.
Sheath and Dilator Systems
Vascular dilators are stiC short catheters with tapered leading edges that are used to
create a soft-tissue tract to facilitate passage of a diagnostic catheter. They are
particularly useful in scarred tissue and obese patients. The opening of the dilator tip
should be exactly matched to the diameter of the guidewire, which must be very
tightly xed during advancement. A stiC guidewire should be used when advancing a
vascular dilator.
Vascular sheaths are thin-walled catheters inserted over tightly matched dilators.

After removal of the inner dilator, the sheath is left in place to allow subsequent
passage of a catheter. Vascular sheaths generally contain a hemostasis valve at the
trailing end, with a side port used for intermittent flushing with heparinized saline or
for injection of contrast material. Sheaths are extremely valuable for stabilizing
access through scarred tissue, vascular grafts, and in obese patients. The sheath also
minimizes the vascular injury at the entry site into the vessel if multiple catheter
exchanges are needed. They are used during virtually all interventions. During
complex procedures such as embolization, the use of a vascular sheath is mandatory
to maintain access and to aid in “rescue” of a kinked or occluded catheter. The use of
even a short (11 cm) sheath will greatly aid in the application of pushing force or
torque to a diagnostic catheter. Long sheaths can straighten tortuous vascular
segments. A wide variety of long sheaths (up to 90 cm) with specialized tips are
available; they enable passage of diagnostic catheters and interventional devices
through tortuous vessels or branches that have acute angles of origin. These tips can
be placed in a proximal selective position and increase stability of vascular access
into the target vessel to assist in placement of a superselective diagnostic catheter.
Injection of the sheath sidearm will allow proximal opaci cation of the vascular
territory, while injection into the superselective catheter allows visualization of the
distal territory. Continued forward ) ushing through the sheath sidearm is mandatory
to prevent clot formation in the space between superselective catheter and sheath.
This coaxial use of sheath and catheter has wide acceptance in more complex
interventional procedures such as crossover angioplasty or carotid and renal artery
stenting.
Angiographic Catheters
The typical interventional radiology suite is stocked with dozens of catheter types. Of
historical note, there are still some active senior “angiographers” (e.g., the authors,
some of the editors) who remember when every angiography suite had a hot plate
and a steam tea kettle. The kettle would be red up to steam-bend the tips and ) are
the hub ends of catheters that were cut from long rolls of polyethylene tubing. The
current bounty of high-quality commercially available catheter designs have obviated
the need to “roll your own.” Advances in materials technology have provided
interventional radiologists with preformed diagnostic catheters that are much more
user friendly, anatomically adaptable, and safer than the catheters available in the
recent past.
Catheters are possibly the most varied products used by the typical interventional
radiologist. It is useful to classify them functionally into two broad general
categories: flush (nonselective) and selective.
Flush catheters must allow high-) ow injections into the aorta or inferior vena cava
and uniform dispersal (with minimal recoil) of contrast media via multiple side

holes. The tip of a ) ush catheter is usually designed to help center the shaft in the
vessel and preclude engagement and injection into a branch vessel; side-hole
placement is typically behind the tip, on the shaft. Flush catheters with such blunt
leading contours can be advanced without a leading guidewire. Flush catheters must
be composed of material with high wall strength and low friction coefficients.
Selective catheters are designed with rotational stiCness to seek a vessel ori ce, but
with enough ) exibility to pass the catheter far into the vessel. Flow rate and pressure
considerations are less important because selective injections are performed at low
flow rates that do not approach the hydraulic limits of the catheter.
Catheters can also be characterized by elements of their engineering:
• Shape of the leading segment (tip)
• Material
• Presence, location, number, and size of side holes
• End-hole diameter, taper
• Length
• Maximal pressure rating
• Hub type
• Radiopacity, presence of sizing markers.
• Size and use (diagnostic catheter, guiding catheter, microcatheter)
All these characteristics are matched to the intended use of the device, aCect
speci c performance parameters, and should be considered when purchasing and
using catheters.
Catheter Shape
13The shape of the catheter tip is perhaps its most essential or defining element.
Flush Catheter
Aortic ) ush catheters traditionally include circular or “pigtail” protective tips. Flush
catheter designs that produce a more compact bolus than traditional pigtail catheters
have been of interest to diagnostic angiographers since the widespread adoption of
14-16digital acquisition in the late 1980s. Variants also include ) ush catheters with
angled shafts that facilitate catheterization of the pulmonary arteries (e.g.,
“Grollman Pigtail” [Cook, Inc., Bloomington, Ind.]) or catheterization of the iliac
artery contralateral to the femoral puncture site (Omni Flush [AngioDynamics,
Queensbury, N.Y.]).
Selective Catheter
For selective catheterization of vascular branches of the aorta or vena cava, a variety
of more complex shapes are needed because of the large size of the trunk vessel
relative to the target vessel origin. Here, selection of the ostium, advancement down
the vessel, and positional stability during subsequent manipulation and injection all

depend on the wall-seeking behavior of the catheter; it must be in contact with the
vessel wall opposite the target branch ori ce. It is rm contact with the back wall
that turns a catheter potentially ) opping in midstream into an eD cient device that
will engage a branch origin and reorient the relatively vertical pushing force applied
at the groin down the axis of the target vessel (Fig. e4-2). For selective
catheterization, the two factors that most in) uence the choice of tip shape are the
diameter of the trunk vessel and the angle of origin of the target vessel. The primary
curve, closest to the tip, is generally chosen to approximate the takeoC angle of the
target vessel. The secondary curve shape is chosen to enable passage of the catheter
more peripherally into the target vessel (over the guidewire). Thus, the shape and
radius of the combination of curves of a catheter should be chosen to maximize
“push-off” from the back wall of the aorta.
FIGURE E4-2 A simple “hockey-stick” catheter ( l e f t ) has a
single curve at tip. Complex elective catheters, such as those in
the Cobra family ( r i g h t ), use primary ( p ), secondary ( s ), and
sometimes tertiary ( t ) curves of different radii to enhance
wallseeking behavior, orifice selection, and pushability.
Some catheter designs use a tertiary curve behind the secondary curve to further
enhance wall-seeking ability. Complex catheters in which the primary and secondary
curves are in the same direction include the Cobra and Head Hunter families. These
catheters can be used right from the package. The Cobra catheter is typically used for
catheterization of down-going vessels such as the visceral arteries, but it may not
work well if the target vessel is steeply angled. Cobra-type catheters are advanced by
pushing and removed by pulling. Waltman and colleagues reported the loop
technique for reversing the curve of a braided Cobra catheter to enable
16catheterization of upgoing vessels such as the left gastric artery. Numerous
selective catheters have primary and secondary curves of opposite orientation (Fig.
e4-3). These recurvant catheters are advanced from the puncture site over a
guidewire and must be re-formed to their original packaged con guration for useafter the guidewire is removed. The larger-radius recurvant catheters used for
selective catheterization (e.g., Simmons II) typically require a re-formation
maneuver that stabilizes the tip while pushing the catheter forward in the aorta.
Selective recurvant catheters generally possess an upgoing tip (when placed by
femoral puncture) that enables selection of an obtuse vessel angle (e.g., left gastric
artery). Once engaged, the catheter is advanced into the vessel over a relatively
) oppy guidewire by pulling until the apex of the secondary curve is reached; at this
point it can be pushed further into the vessel by “breaking the curve” over a stiCer
trailing segment of guidewire. It is the purchase gained by pulling down on the
catheter that enables recurvant catheters to engage and conquer steep obtusely or
acutely angled branch vessels, which a Cobra shape cannot do. Removal of a deeply
embedded recurvant catheter requires careful disengagement of the catheter from a
selective position by a ) uoroscopically guided push into the aorta and subsequent
straightening with a guidewire or by pulling the catheter into a favorable anatomic
location such as the iliac bifurcation.
FIGURE E4-3 The opposite orientation of primary ( p ) and
secondary ( s ) curves of the Simmons II catheter ( l e f t ) defines its
recurvant nature. Cobra II catheter ( r i g h t ) demonstrates primary
and secondary curves oriented in the same direction.
End Holes and Side Holes

Diagnostic catheters possess end holes to allow passage over a guidewire. The end
hole should be closely tapered to the guidewire diameter to maximize the ability to
push without kinking the wire.
Flush Catheters
During ) ush angiography, multiple side holes will enable high ) ow rates with even
dispersal of contrast material. The traditional pigtail ) ush catheter possesses 8 to 12
large side holes on the distal end of the shaft behind the pigtail tip (Fig. e4-4). The
end hole of a ) ush catheter is more distal to and typically smaller than the combined
cross-sectional area of the side holes on the shaft. Thus, the jet and volume of
contrast material exiting the end hole are relatively restricted. By structural
necessity, the side holes must be smaller than the catheter end hole; therefore, a
guidewire matched to the end hole cannot exit through them. Current ) ush catheters
are designed from relatively rigid 4F to 6F material. Catheter end-hole jets are
always turbulent and have signi cant negative pressure eCects that can cause severe
12,17localized intimal and subintimal trauma. Damage at a given ) ow rate and
pressure increases with smaller end-hole size. Fluid mechanical modules have
demonstrated that end-hole size is the single most important factor aCecting jet
17penetration during angiographic injection. Furthermore, end-hole catheters may
experience signi cant recoil that may dislodge them during selective injection of
contrast agent or vigorous flushing.
FIGURE E4-4 Flush catheter side-hole placement. Traditional
pigtail ( l e f t ) and modified pigtail (Omni Flush [ r i g h t ]) designs
have side holes on catheter shaft, proximal to a centering tip.
Middle catheter (Neff) has side holes on the limb to facilitate
injection into contralateral common iliac artery.



Selective Catheters
To diminish end-hole jet eCects, selective catheters may be con gured with one or
two small side holes located within 2 mm of the tip. These side holes are much
smaller than the catheter end hole and are smaller than the side holes on ) ush
catheters. Side-hole diagnostic catheters have drawbacks, however. Thrombi can
more easily form between the side hole and catheter tip as a result of static blood
residing there secondary to retrograde hydrostatic pressure. A low-power continuous
) ush solution tends to exit the proximal side holes rather than the tip end hole.
Thrombi may be forced into the circulation with a forceful forward hand ) ush or
power injection. Thus, many operators will frequently “double ) ush” all side-hole
catheters by rst withdrawing the in-catheter static column and subsequently using a
second syringe for the forward ) ush. Because of the potential for such thrombus
formation, diagnostic catheters originally designed for neurodiagnostic work are
con gured without side holes. Side-hole catheters should not be used for
embolization. Embolization coils can snag on catheter side holes and result in failure
of delivery or embolization of nontarget structures. Gelfoam and particulate matter
can be diD cult to deliver and may occlude the catheter tip because of decrements in
pressure distal to the side holes. Catheters with suspected tip occlusion should not be
) ushed forward and should not be advanced with guidewires; they should be
removed. Side-hole selective catheters may be of value during blood sampling from a
branch vessel such as the adrenal vein; if the catheter is advanced suD ciently into
the target vessel such that the side holes are selective, withdrawal of blood is
facilitated because the end hole is no longer suctioned against the endothelium.
Materials
Catheter qualities that directly in) uence catheter maneuverability and stability
include stiCness, torque, memory retention, and ) exibility (ability to follow a wire).
Additional material characteristics include the coeD cient of friction, burst pressure,
thrombogenicity, static and kinetic friction, microscopic surface topology, and
surface roughness. These traits directly in) uence the quality, quantity, and safety of
18injection of contrast agents and can be tested in the laboratory. Re nements in
technology allow mixing of materials such that specialized catheters may be designed
19with physical properties that vary along the length of the device.
A wide variety of materials are used in fabricating contemporary catheters. Te) on
(polytetra) uoroethylene [PTFE]-62 [DuPont, Wilmington, Del.]) is a resin ubiquitous
20in medical and commercial applications that was patented in 1938. It is an
extremely large inert molecule characterized by a low coeD cient of friction, in part
because of its tendency to become hydrophilic when wet. When extruded for use in
medical catheters, it is moderately stiC and has high tensile strength and burst
pressure. Thus, high-) ow ) ush catheter designs often use Te) on. Te) on is likewise

favored for use in vascular sheaths and dilators because of its good memory,
stiCness, and kink resistance, characteristics that facilitate tracking through obese
groins, scar tissue, or vascular grafts. Nylon is also used for ) ush catheter
construction. The high tensile strength of nylon allows thin-walled catheters (i.e.,
those with large lumen size relative to outer wall diameter) to withstand
highpressure, high-) ow injections. Nylon resists softening with prolonged exposure to
body temperature and blood. Polyethylene is typically used for selective catheters. Its
relative lack of stiCness allows it to follow guidewires placed into selective position,
with little damage to the endothelium. Its proclivity to soften with time and repeated
manipulation may sometimes cause it to lose shape and torsional rigidity during
extended procedures. Polyethylene catheters with diameters of 4F and 5F are
typically braided to support preservation of shape and torque. Barium sulfate,
tungsten, or lead salts are used to increase fluoroscopic visibility.
From a materials engineering perspective, the ideal angiographic catheter should
be rigid enough to be pushed and twisted while maintaining structural integrity.
Axial rigidity is necessary to push the catheter. However, there also must be variable
) exibility to bend and follow the curve of the guidewire and vessel, especially
toward the leading edge. The catheter should be designed to avoid or minimize tissue
damage, be biocompatible, and maintain reliability with time. Recent trends in
catheter design have favored very high torsional rigidity, especially as catheter
diameters have decreased. However, the high torsional rigidity of a catheter material
does not preclude designing it with suD cient ) exural rigidity because these are two
19distinct material characteristics. By embedding mechanical braiding (nylon or
more typically stainless steel) in the catheter wall, torsional and ) exural rigidity is
signi cantly augmented. Stainless steel can be used to achieve 1 : 1 torque control.
Braiding greatly facilitates selective catheterization.
A materials parameter closely related to catheter rigidity and pushability is
bending stiCness. Commercially available in vitro stiCness testing modules use laser
scan micrometry, are reliable and reproducible, and can therefore be used to guide
21manufacturers in catheter design. Buckling will occur if friction forces between the
catheter and vessel are suD ciently elevated or, more frequently, if the catheter is
wedged into or caught on the wall but has not yet perforated it. Although the
operator can use a guidewire to stiCen a catheter and protect the tip during
advancement, resistance to buckling is nevertheless a very desirable property for a
catheter wall. Although a necessity for high-) ow ) ush catheters, low-friction
materials are desirable even for selective catheters. Just as high ) ow rates are
facilitated by low friction coeD cients on the luminal surface, decreased friction on
the external catheter surface enables easier advancement of the catheter, with
reduced wedging. Hydrophilic polymer catheter coatings are useful in this regard
because they allow easier tracking, but some positional stability is sacri ced during22injection.
Size and Use
Larger-bore braided catheters can provide stable access to aortic side branches. These
so-called guiding catheters will be used in conjunction with smaller catheters in a
coaxial fashion, where a smaller catheter, usually a microcatheter or percutaneous
transluminal angioplasty (PTA) balloon will be advanced through the guiding
catheter into the periphery of the vascular bed. Guiding catheters in sizes 5F to 8F
23with various tip shapes are available. The coaxial technique requires meticulous
flushing of the guiding catheters through a side arm or a Tuohy Borst–type adapter to
prevent clot formation around the introduced inner catheter. The combination of a
6F guiding catheter with a 3F microcatheter will allow the operator to obtain an
angiogram after contrast injection into the sidearm of the guiding catheter. The
inner lumen of a smaller selective catheter used as a guide is too small to allow a
forceful contrast injection if a microcatheter is introduced.
Microcatheters are small catheters with an outer diameter of 3F or less. The inner
lumen of these catheters varies from 0.010 to 0.028 inch, and the catheter length
between 105 and 150 cm. Formerly, a distinction between wire-directed
microcatheters and ) ow-directed microcatheters, usually close to 0.010 inch, was
made; however, with the possibility of wire manipulation of newer ) ow-directed
microcatheters and the advent of extremely ) oppy-tipped braided microcatheters,
the distinction is more blurred. Small ) ow-directed microcatheters are used for
diD cult access through small feeding vessels such as the embolization of intracranial
arteriovenous malformations (AVMs) or the transarterial treatment of the
24prostate. Wire-directed microcatheters vary a great deal in distal maneuverability.
These catheters are generally braided, which makes them less vulnerable to kinking
or rupture but also reduces the ability to steam-shape the catheter tip. Most of these
catheters are straight, but catheter tips at a 45- or 90-degree angle are available.
Hydrophilic coating allows them to gain more distal access than nonhydrophilic
microcatheters, but at the cost of greater instability. Microcatheters for delivery of
aneurysm coils have two markers at the distal end to allow alignment of the
detachment zone with the microcatheter tip (Fig. e4-5). Microcatheters with a larger
inner lumen are commonly used for delivery of larger embolic particles.FIGURE E4-5 Typical interaction with guide catheter and
microcatheter for embolization of an intracranial aneurysm. A 6F
guiding catheter is first positioned in internal carotid artery
( a r r o w ). A microcatheter is then advanced through guiding
catheter and from there into aneurysm sac. Contrast injection
through guiding catheter allows visualization of vascular tree.
The two radiopaque markers ( a r r o w h e a d s ) on microcatheter
allow alignment of microcatheter tip with coil delivery device.
Other Characteristics
Automatic contrast-agent injectors must be set below the catheter burst pressure,
which is directly proportional to the catheter wall thickness and material tensile
25strength and inversely proportional to the internal radius. Catheter rupture
typically occurs at the trailing (hub) end of the catheter, where the pressure is
highest and the catheter may be relatively weak because of the presence of the
hubshaft junction. This is a fortunate byproduct of friendly physical principles and
preferable to rupture distally, in the bloodstream. The high ) ow rates used for ) ush
aortography necessitate high burst pressure ratings for ) ow catheters. Poiseuille's

equation for laminar ) uid ) ow through a uniform (rigid) pipe describes the
4important catheter parameters that determine flow rates: F = ΔP π r /8 η L.*
Because the ) ow rate is proportional to the fourth power of the radius, a small
reduction in catheter diameter will markedly decrease the allowable maximum ) ow
rate. Given current materials, contrast agents, and imaging systems, 4F is probably
the technical lower limit for ) ush catheters. Increasing catheter length will
proportionately decrease the maximal ) ow rate. In general, one should choose the
smallest-diameter catheter possible for a diagnostic arteriogram. The size of the
catheter relative to the access-site artery appears to be the most important factor in
26producing spasm and thrombosis. However, in one large study involving cardiac
patients randomized to 4F or 6F diagnostic catheters, complication rates were similar
in both groups, so femoral spasm may not present a problem within the range of
27catheter sizes generally used in adult patients. The use of smaller 4F catheters for
coronary angiography has been shown to allow earlier ambulation (2 hours) than is
typical with 5F and 6F catheters, but a smaller catheter may compromise image
quality and ease of handling because of limitations in ) ow rate and less
28-31torquability.
Catheter hubs and connecting tubing for angiographic injection are typically
) anged and use threaded locking Luer connections. The original Luer-Lok design was
used as the connector on the BD Yale Luer-Lok syringe, which was introduced in
321925 and later adapted to catheter, stopcock, and tubing use. These connections
may link devices from diCerent vendors and manufacturing processes. Thus,
adherence to strict design standards is mandatory to ensure compatibility, eD cacy,
33and safety. Current Luer-Lok connections adhere to the rigorous ISO standards.
Poorly tted connections can result in separation during injection and have been
34reported to allow the development of air emboli. Separation is an infrequent
event that is often related to misaligning or “cross-threading” the connectors; it is the
authors' opinion that separation is more frequent when metallic catheter hubs and
plastic connecting tubing are mixed.
Angiographic Guidewires
Standard angiographic guidewires are composed of stainless steel springs tightly
wound around a stiC mandrel core that is welded to the trailing end of the wire. A
small-gauge internal safety wire is usually present to prevent the spring wire from
uncoiling. Guidewires must interact with the needle, diagnostic catheter, and vessel
wall in a manner that allows safe access, guidance along the vessel, and selective
catheterization. The outer spring is usually coated with Te) on. Characteristics that
are independently incorporated into a speci c guidewire design include mandrel tip
tapering, mandrel stiCness, tip shape, length, and diameter. The mandrel core ischaracterized by its stiCness and leading taper, two key properties of the overall
guidewire design. Standard mandrel tapers are typically 5 cm. Spring-wound
guidewires with longer tapers were historically used for maneuvering in selective
and tortuous vessels but have largely been supplanted by hydrophilic wires, which
are also available with varied mandrel tapering and stiCness (LT [long taper] 10 cm;
LLT [long long taper] 15 cm). Bentson guidewires are constructed with LLT mandrels
that terminate at a distance from the tip of the spring, thereby creating an extremely
) oppy leading segment. It was the Bentson wire that was used for the classic
35“guidewire” test for acute thrombus lysability. Exchange wires, which need
stiCness at the leading edge to maintain vessel purchase during withdrawal and
advancement of the catheter, typically include a short leading mandrel taper (e.g.,
2 cm for a Rosen wire). Mandrel shafts can be constructed with varying stiffness. It is
the interplay between the catheter and guidewire characteristics, especially their
relative leading stiCness, that determines how well a catheter can be advanced
selectively (Fig. e4-6). The stiffness at the leading aspect of the wire is determined by
both the stiCness of the mandrel core and its taper length. Softer guidewires can be
advanced easily out of a catheter deep into a vascular branch, but the catheter may
have diD culty following the wire. The stiCest guidewire type (i.e., Lunderquist) is
typically reserved for interventions requiring manipulations with large-bore devices;
in aortic endograft placement, this guidewire can support the advancement of large
sheaths and straighten tortuous iliac artery segments. This ultimately stiC wire was
originally intended for nonvascular interventions and should be used with extreme
caution in the vascular system. Moderately stiC guidewires (i.e., Amplatz-type “extra
stiC” or “super stiC,” Rosen type) are more typically used for diagnostic and
interventional catheter manipulation and exchange in the vascular system for
percutaneous procedures and can be very helpful in patients with tortuous
vasculature or for access through a hostile or obese groin. Guidewires are used to
lead catheters as they are advanced in a vessel, and thus must have ) exible tips to
minimize wall damage. However, a ) oppy tip will stiCen and straighten as it is
advanced out of the catheter or needle tip because the trailing segment is
constrained in the catheter; as the guidewire exits, it will regain its ) exibility over a
distance of 2 to 3 cm. Thus, many operators perform a “tip exchange” while
advancing a guidewire out of the catheter tip to minimize the chance of dissection. In
this maneuver, the wire is advanced to the catheter tip, which is then retracted
slightly before advancing the guidewire further. Movable core guidewires can be
used if variable stiCness is needed, but these wires are often of limited value because
of diD culty actually moving the core in vivo. Steerable or de) ecting-tip guidewires
have mandrel cores whose tips can be shaped by manipulations at the trailing
handle. De) ecting-tip wires have been popular for advancing through the pulmonary
valve. These specialty wires were more valuable historically when catheters were

larger and more rigid and before the advent of hydrophilic guidewires. Both straight
and J-tipped standard guidewires are available. J tips are used for minimizing wall
damage in atherosclerotic arteries during advancement because the leading J edge is
blunt. Small-radius J tips (e.g., 1.5 mm) allow safer purchase in branch vessels (e.g.,
during exchange). Standard and larger J tips can prevent catheterization of the
ori ce of a non–target branch vessel smaller than the tip diameter. Standard
guidewires are 145 to 150 cm in length. This length was chosen for femoral access,
advancement of the wire tip to the diaphragm, and placement of a standard 90-cm
) ush catheter with minimal ) uoroscopic con rmation. Longer wires are needed for
exchanging a catheter while the tip is in a selective position. To maintain selective
guidewire position during catheter exchange, the length of the wire must exceed the
sum of the distance from the puncture site to the target vessel and the catheter
length. This will always leave exposed controllable wire at the puncture site or hub
end. For an abdominal visceral exchange wire, 180 to 200 cm will suD ce. However,
to allow maximum ) exibility, the length of an exchange wire must be at least twice
as long as the longest catheter with which it will be used to allow exchange when the
catheter is inserted to its maximal reach (i.e., “hubbed”).
FIGURE E4-6 Interaction between guidewire shaft stiffness
and catheter stiffness and shape. A 5F Cobra II catheter shape
deforms as a Newton LT guidewire is advanced and the stiffer
portions of guidewire mandrel taper are pushed through the
leading primary and secondary curves. Knowledge of this
relationship is typically the key to successful selective and
superselective catheterization. Ignorance of this relationship will
hinder catheter placement or even kick a catheter out of
position.

All catheters or device delivery systems where the guidewire enters the hub and
leaves at the tip are called over-the-wire systems. A variant to this classic
angiographic approach are monorail or rapid exchange systems. In these systems, the
guidewire does not enter the catheter at the hub but at a side hole at the shaft of the
catheter. The guidewire still leaves the catheter at the tip, but only the last 5 to
20 cm of the catheter run over the guidewire. For the remaining length, catheter and
guidewire run in parallel. These systems facilitate the exchange of catheters because
the guidewire can be held in place while retracting the catheter, and the guidewire
length only has to exceed the catheter or device length by the distance between side
hole and catheter tip. Many of these monorail/rapid exchange systems use smaller
guidewires, usually 0.014 or 0.018 inch in diameter.
Shorter wires, such as 80 cm, are available for convenience in manipulations
performed close to the puncture site, such as central line placement or dialysis access
intervention.
Coatings
Te) on is typically used to coat spring-wound guidewires to decrease the coeD cient
36of friction. Though exceedingly rare, Te) on embolization has been reported.
34Spring guidewires are very thrombogenic. Blood contact time should be limited,
and the wires must be wiped down scrupulously; because both wire and catheter
thrombi may be stripped and dislodged during withdrawal, a systemic heparin ) ush
12must be used. Thrombus adhesion and propagation are augmented by the
nonlaminar ) ow and relative stasis around the wire or catheter. Heparin can be used
36-38to coat guidewires and catheters and thus reduce thrombogenicity. However,
37-39this eCect is short lived, about 5 to 10 minutes. In patients with
heparininduced thrombocytopenia syndrome, heparin-coated catheters and guidewires and
heparin-containing ) ush are contraindicated because they can induce
39-41thrombocytopenia. Other coatings, such as glycosaminoglycans and
42,43antithrombin-heparin covalent complex, have shown promise experimentally.
Hydrophilic guidewires and catheters are signi cantly less thrombogenic than
44traditional spring wires, although this eCect may be lost by 45 minutes.
Hydrophilic copolymer–coated, nitinol-cored guidewires have largely replaced
standard coil spring wires in most interventional suites.* This family of alloys
exhibits unique behavior. The metals are superelastic and deformable and exhibit an
extraordinary thermal shape memory effect.
When wet, their low friction coeD cients facilitate advancement in tortuous
arteries even if the wire is relatively stiC; subsequent catheter advancement and
45manipulation are also made easier. The wires are widely available with
angledand straight-tip con gurations and in multiple diameters and stiCness. Most
operators do not use a hydrophilic wire as a primary puncture wire, because it tends
to be diD cult to stabilize during vascular access, and there is concern for
embolization of the wire coating if the wire is pulled back through the puncture
needle. Though less thrombogenic than standard spring guidewires, hydrophilic wires
must be kept scrupulously clean with heparinized saline.
Wire Diameter
Typically, standard guidewires are 0.035 or 0.038 inch in diameter. They should be
tightly matched to the catheter end hole. The catheter end-hole size is important if
subsequent transcatheter intervention or coaxial techniques will be used. The
0.035inch technique has seemingly supplanted the 0.038-inch technique because of the
downsizing of diagnostic catheters to 4F, but a 0.035-inch end hole will not allow
subsequent passage of 3F (0.038-inch) devices. Advances in guidewire design have
enabled some 0.035-inch wires to have the stiCness previously achievable only with
0.038-inch wires. In addition, conventional 0.038-inch embolic coil systems are now
available in 0.035 inch. Attention to disposable device inventory is essential to
ensure compatibility of devices during both diagnostic and interventional
procedures.
Microwires are generally of 0.014- to 0.016-inch caliber. Even smaller guidewires
of 0.10 inch are available. With the conversion of technology, these guidewires tend
to be very similar in performance from one company to another. Steel-reinforced
microwires are also available and can be useful for extremely tortuous vessels to
support a microcatheter, where other wires are too deformable. Most of the newer
microwires have hydrophilic coating and must be kept wet with saline. Most of these
microwires are delivered with a straight tip, and the tip must be con gured prior to
use by gently pulling it over a needle or the provided introducer device.
Summary
The angiographic catheters, guidewires, and needles devised about a half century
ago have continually evolved and still form the basis for the eCective and safe
diagnostic and interventional techniques in contemporaneous use. This evolution has
depended on the inventiveness of myriad interventionalists, as well as on continued
progress in materials technology. An understanding of the basic principles of
catheter and guidewire engineering will facilitate eCective interventional and
clinical care.
Key Points
• Diagnostic catheters can be characterized by their design elements,
including shape, material, and side-hole location.
• For selective catheterization, the two factors most influencing the choiceof tip shape are the diameter of the trunk vessel and the angle of origin
of the target vessel.
• Side-hole catheters should not be used for embolization.
• Attention to disposable device inventory is essential to ensure
compatibility of devices during both diagnostic and interventional
procedures.
• In patients with heparin-induced thrombocytopenia syndrome,
heparincoated catheters and guidewires and heparin-containing flush are
contraindicated because they can induce thrombocytopenia.
▸ Suggested Readings
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Katzen, BT. The future of catheter-based angiography: implications for the vascular
interventionalist. Radiol Clin North Am. 2002; 40:689–692.
Mitty, HA. Advances in angiography and their impact on endovascular therapy. Mt
Sinai J Med. 2003; 70:359–363.
Pöll, JS. The story of the gauge. Anaesthesia. 1999; 54:575–581.
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41. Laster, JL, Nichols, WK, Silver, D. Thrombocytopenia associated with
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44. Leach, KR, Kurisu, Y, Carlson, JE, et al. Thrombogenicity of hydrophilically
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*In this equation, is the flow rate, is the pressure drop across the catheter, isF ΔP r
the internal catheter diameter, η is the viscosity of the contrast medium, and L is
catheter length.
*Nitinol: ckel, tanium, aval rdnance aboratory.ni ti N O L
C H A P T E R 5
Balloon Catheters
Shawn N. Sarin, Wael E.A. Saad, David Nicholson, Ulku C. Turba, J. Fritz Angle, Klaus D. Hagspiel,
Michael D. Dake and Alan H. Matsumoto
Although Dotter and Judkins rst described percutaneous transluminal angioplasty (PTA) in
1 21964, use of the procedure did not gain momentum until 1976, when Gruentzig described his
double-lumen balloon catheter. The Gruentzig balloon catheter incorporated balloon material that
was relatively noncompliant and mounted on small catheters (7F-8F) that could be advanced
coaxially over a guidewire. Since its introduction, the design of balloon catheters has improved as
technology has evolved.
Physical Principles of Balloon Dilation
It is important for one to understand the physical principles that govern the e0ects of balloon
3,4dilation. Dilating force is the outward force exerted against a luminal stenosis. It is dependent
on balloon diameter, the balloon's in3ation pressure, compliance of the balloon material, balloon
3,4length, and the degree of stenosis. The law of Laplace states that the force or tension (T) exerted
on the wall of the in3ated balloon is directly proportional to the pressure (P) within the balloon
and the radius (R) of the balloon (T = P × R) (Fig. e5-1). Thus, a balloon with twice the radius of
a smaller balloon will exert twice the tension on the wall of a balloon for a given in3ation
pressure. If the diameter of the balloon is kept constant, the tension on the wall of the balloon
will increase linearly with increases in in3ation pressure (Fig. e5-2). Because the tension on the
balloon wall translates into dilating force, the dilating force generated by a balloon is directly
proportional to the balloon's diameter and in3ation pressure. Therefore, larger balloons will
require less pressure than smaller balloons to generate substantial dilating force (Fig. e5-3).
Similarly, larger vessels such as the abdominal aorta or the common iliac arteries require less
pressure to dilate and rupture. The pressure within an angioplasty balloon is universally measured
in atmospheres (atm). An atmosphere is a unit of pressure that will support a column of mercury
760 mm high at sea level and 0°C.
FIGURE E5-1 Law of Laplace.
FIGURE E5-2 The outward force generated by a balloon is a function of
inflation pressure.
FIGURE E5-3 For the same inflation pressure, balloon B will produce twice
the dilating force of balloon A.
Compliance is a measure of how much a balloon will stretch beyond a predetermined diameter
when a force is applied to it (Fig. e5-4). All balloon materials are elastic. Consequently, all
balloons have some inherent degree of compliance. A completely noncompliant balloon will not
stretch beyond a predetermined diameter—despite increases in in3ation pressure—and will
maintain its pro le and shape with repeated in3ations (Fig. e5-5, A-C). The pressure that would
cause permanent deformation of a noncompliant balloon (tensile strength) would approximate
the pressure required to rupture the balloon (yield strength). If the balloon material is compliant,increases in in3ation pressure will result in further balloon expansion, especially in areas of lower
resistance (i.e., in the adjacent normal vessel lumen rather than in the area of stenosis). Balloon
compliance prevents the dilating force from being concentrated in the region of the stenosis (Fig.
e5-6). Therefore, when compared with a relatively compliant balloon, a noncompliant balloon
will have a more predictable diameter at various inflation pressures and provide a greater amount
of dilating force in a lesion. As balloon pressure is increased, semicompliant balloons continue to
expand in diameter. When in3ated in a resistant lesion, the balloon “hourglasses” or “dog bones”
(see Fig. e5-6), thereby creating stress injury and deformation of adjacent normal vessel segments.
Based on a vessel wall displacement model using a noncompliant polyethylene terephthalate
(PET) balloon and a semicompliant nylon balloon, both in3ated to their respective rated burst
pressure (RBP) and matched to the internal diameter of the vessel model, greater vessel
deformation is seen on either side of the lesion with the semicompliant balloon. A simulation
stress model shows that in a typical 8-mm vessel, a semicompliant balloon produces large
variations in wall stress in the adjacent nonstenotic segments of the vessel, whereas vessel wall
stress remains relatively constant with inflation of a noncompliant balloon (Fig. e5-7).
FIGURE E5-4 The noncompliant balloon ( A ) will not enlarge beyond a
predetermined diameter.FIGURE E5-5 A, Balloon compliance is variable and affected by balloon
composition. B, More characteristic compliance curve of a relatively
noncompliant percutaneous transluminal angioplasty (PTA) balloon. A is
inflation pressure at which balloon reaches its nominal diameter; B is pressure
at which tensile strength of balloon equals its yield strength. Inflation
pressures above B cause balloon to rupture. C, Compliance curve of a
relatively compliant nylon balloon.
FIGURE E5-6 Increased compliance results in decreased dilating force at
stenosis.

FIGURE E5-7 A, Inflation of a noncompliant balloon inflated to its rated burst
pressure (RBP) shows minimal deformation of vessel on either side of lesion.
B, Inflation of a noncompliant balloon to its RBP shows a moderate degree of
balloon and vessel deformation on either side of lesion. C-D, Graphic
representation of stress delivered by an 8-mm noncompliant balloon inflated
to its RBP to the wall of an 8-mm vessel (C), as compared with an 8-mm
semicompliant balloon (D) inflated to its RBP. Note the large variation in
stress to vessel wall created by the semicompliant balloon. (Courtesy CR
Bard, Inc.)
The length of the balloon also has an e0ect on dilating force when the balloon material is
compliant. Compliant balloons will continue to increase in diameter and deform with increasing
in3ation pressure. Therefore, a shorter compliant balloon with a smaller surface area will exert a
more concentrated dilating force than a longer compliant balloon will. In contrast, the dilating
force generated by a balloon constructed from noncompliant material is not a0ected by
increasing balloon length.
A longer lesion has a larger total area of stenosis than a shorter one does. As a result, the
dilating force created by a balloon is greater in a longer lesion. In addition, the dilating force
generated in a lesion is directly proportional to the degree of stenosis for a xed balloon diameter
and in3ation pressure. As such, more dilating force will be generated in a tight, high-grade
stenosis than in a shallow stenosis (Fig. e5-8). This principle is governed by the so-called
clothesline e0ect. That is, the radial force vector generated by a balloon in a stenosis is greatest
when the balloon has more of a “waist” on it (Fig. e5-9). This outward force vector decreases as
the waist on the balloon diminishes. Therefore, continuing to increase balloon in3ation pressure
to eliminate a minimal residual waist will result in relatively small incremental changes in
dilating force and is more likely to rupture the balloon. In this setting, low-pro le “high-pressure”
balloons o0er an advantage over low-pressure balloon catheters. In the past, if a residual waist
could not be resolved, the procedure was either terminated or a larger balloon was used. With the
use of a larger-diameter balloon, more dilating force can be generated, but the risk of rupturing
the vessel or creating a dissection “flap” is also increased.FIGURE E5-8 For a given balloon and inflation pressure, more force will be
generated in high-grade than in low-grade stenosis.
FIGURE E5-9 The greatest force is generated in lesions with the smallest
luminal diameter.
Balloon Materials
Most balloons are currently made of PET or nylon derivates (Table 5-1). In the past, other plastic
polymers such as polyvinyl chloride (PVC), polyethylene (PE), or reinforced polyurethane have





5-8 2been used. PVC, the material that was used in the original Gruentzig balloon catheter, shows
a moderate degree of compliance even at nominal balloon in3ation pressures. In vitro studies have
shown that balloon diameter can increase from the rst to the second in3ation by 5% to 17% and
5,6by as much as 33% after six in3ations. PVC balloons also deform and elongate with increasing
7in3ation pressure. They rupture at signi cantly lower in3ation pressures than balloons
3,5constructed from other materials. Therefore, PVC has largely been abandoned as a balloon
material.
TABLE 5-1
Characteristics of Balloon Materials
Maximum
Tensile Compliance Rated
Materials Stiffness Profile Sterilization
Strength (Relative) Pressure
(atm)
PET High Low High Low 20 EtO or
radiation
Nylon Medium- Medium Low Low 16 EtO
high
PE Medium Medium Low Medium 10 EtO or
radiation
PET/PE Very high Very low High Medium 30 EtO
fibers and
Pebax
PVC Low High Medium High 6-8 Radiation
NyBax High High Low Low 24 EtO or
Radiation
E t O , Ethylene oxide gas; P E , polyethylene; P E T , polyethylene terephthalate; P V C , polyvinyl chloride.
PE is an inert plastic that contains no additives. PE balloons are less compliant than those made
5,7from PVC. They show only minor increases in diameter ( although lower-pro le PE balloon
catheters (made with thinner PE) are slightly more compliant. PE balloons generate almost twice
as much dilating force as the same size PVC balloon and have higher burst pressures than PVC
3,6balloons. PE balloons are more scratch resistant than PET balloons in that they tend to
perforate less often in calcified lesions and stents.
PET is a polyester derivative and is the material used in commercial thin-walled plastic bottles.
It gained popularity with its use in low-pro le and small vessel balloon catheters. Balloons made
from PET are much less compliant than both PVC and PE balloons and can usually be made with a
lower pro le. Despite being very thin walled, balloons made from PET can tolerate very high
in3ation pressures. Balloons made from PET tend to be more prone to puncture on calci ed
plaque or metal stents, and therefore should not be used in these situations.
Nylon-derivative balloons have variable in3ation pressure and compliance characteristics,
depending on their individual proprietary composition. Nylon balloons tend to be more compliant






than those made from PET, but less or similar in compliance to PE balloons. Nylon balloons are
more scratch resistant than PET and PE balloons, are softer, and have proved to be ne balloons
on which to mount stents. In addition, nylon balloons tend to have good deflation profiles.
To take advantage of the various properties of balloon materials, industry has created
coextruded copolymers, as well as balloons made of multiple layers of the various polymers. The
least compliant balloon dilation catheters that are currently available are the Conquest (6- to
10mm diameters) and Atlas (12- to 18-mm diameters) balloons (Bard Peripheral Vascular, Tempe
Ariz.). These balloons demonstrate a maximum of 0.25-mm growth above their nominal diameter
when in3ated to 30 atm and have a unique three-layer design. The inner layer is constructed of
noncompliant PET material. Ultrahigh-molecular-weight PE bers are wrapped circumferentially
and longitudinally around the inner PET layer. The PE bers are aL xed to the inner PET material
by an extremely thin covering layer of polyether block amide (Pebax) material. The RBP of these
balloons is 30 atm. Although the catheter shaft is a coaxial design, the inner Pebax layer of the
catheter does not compress despite the use of high in3ation pressure. The balloon is relatively
puncture resistant; however, if a stent strut or calci ed plaque punctures the balloon between the
ultrahigh-molecular-weight PE bers, a pinhole leak will develop. In addition, the Pebax covering
makes it more likely for balloon-expandable stents to slip on this balloon material.
Another type of multilayer balloon material is NyBax (a coextrusion of nylon and Pebax
thermoplastic elastomer), which is currently used in the Mustang and Coyote Balloon Dilation
Catheters (Boston Scienti c Corp., Boston, Mass.). Like PET, NyBax balloons can tolerate very
high in3ation pressures (up to 24 atm RBP in the Mustang balloon) despite being thin walled.
Thin-walled material results in a lower pro le and generally better sheath performance than a
thicker-walled balloon material of the same diameter. Use of a coextrusion containing nylon and
thermoplastic elastomer also results in a balloon that is softer and more 3exible than one
composed solely of PET or PE.
Catheter Design
2The Gruentzig balloon was a coaxially designed double-lumen catheter (Fig. e5-10, A and B). The
inner catheter was surrounded by a thin tube of PVC with an expandable end (the balloon). The
inner and outer catheters were bonded together with heat. This coaxial design became less
popular because of the suboptimal compliance characteristics of PVC and concern for
overexpansion of the outer lumen at higher in3ation pressures and resultant compression of the
5,7inner lumen. In addition, with de3ation, the overstretched outer catheter sleeve can become
redundant and “accordion” and “bunch up” when attempts are made to withdraw the catheter. A
potential advantage of a coaxial catheter design is that balloon in3ation and de3ation times are
faster than with comparably sized double-lumen balloon catheters. By having the guidewire lumen
central in location and concentrically oriented, longitudinal pushability and the ability of the
catheter to track over a guidewire are improved. However, catheters of this design are now
limited to small vessel balloon catheters, where according to the law of Laplace, compliance is less
of a problem. Some companies have released larger balloon catheters with a coaxial design whose
shafts are made of materials less compliant than PVC.FIGURE E5-10 A, Gruentzig-type balloon. B, Gruentzig's coaxial design.
Most modern balloon catheters are true double- or triple-lumen catheters (Fig. e5-11). The shaft
is usually composed of a polyester, PE, nylon, or polyamide derivative. The balloon is attached to
the catheter shaft by some adhesive or thermal bonding, or both. The outer smaller lumen, which
communicates with the side port, is used to in3ate and de3ate the balloon. The shape of the
lumen that communicates with the balloon varies and may be round, crescenteric, or a half circle.
In3ation and de3ation characteristics of the balloon may vary depending on the size and shape of
the second or third lumen.FIGURE E5-11 Multiple-lumen balloon design.
With the wide variety of guide catheters and sheaths that have become available, the
rapidexchange (monorail) catheter system has become one of the most popular balloon catheter
designs. This system has an exit port for the guidewire (termed the skive) approximately 40 cm
proximal to the balloon (Fig. e5-12). The proximal port of the catheter communicates with the
balloon. A sti0ening wire is often incorporated into the shaft of the catheter to improve catheter
pushability. A major advantage of this system is that there is no need to use exchange-length
guidewires despite considerable catheter length. Another advantage is that the large lumen
communicating with the balloon makes balloon inflation and deflation times rapid. Disadvantages
associated with a monorail design include absence of a port through which to inject contrast and
the possibility that the balloon catheter may not track as well through tight lesions or tortuous
vessels. However, most monorail balloons are used through guide catheters or sheaths, making
trackability less of an issue.
FIGURE E5-12 Monorail balloon design.
9Another balloon catheter design popularized by Charles J. Tegtmeyer in the mid-1980s is the
“balloon on a wire” (Fig. e5-13). The design consisted of a polymer-coated, braided, stainless steel





guidewire with a hollow core that communicated with a PET balloon. The segment immediately
adjacent to the balloon was constructed in a fashion that made it more 3exible than the proximal
portion of the guidewire shaft. Distal to the balloon, there was a variable-length platinum or
polyamide 0.018- to 0.022-inch wire tip. The intent of this balloon design was to create a
lowpro le, torquable balloon dilation system that was used with a guide catheter. However, as
balloon catheter technology progressed, this design was supplanted by coaxial and monorail
0.014- to 0.018-inch systems.
FIGURE E5-13 Balloon-on-a-wire design.
Modi cations of basic balloon catheter designs have resulted in special-application balloon
catheters that use thermal energy and microsurgical blades. The PolarCath (Boston Scienti c,
Natick, Mass.) cryoplasty balloon catheter system includes two balloons made of Pebax material.
Nitrous oxide gas under pressure is contained in the inner balloon, and the outer balloon expands
passively as a result of its coaxial design. When in3ated, the cryoplasty balloon reaches a
temperature of −10°C. In between the two balloons is a third layer of insulation fabric to
minimize the risk of leakage of the nitrous oxide gas. For gas to escape into the vessel, all three
layers would have to be compromised. Additionally, inside the inner balloon where the gas is
contained are a thermocouple and pressure transducer that are continually monitoring pressure
and temperature. If any abnormal changes in pressure or temperature are detected, the computer
in the in3ation unit automatically stops the in3ation cycle and evacuates the gas (see later
discussion).
The Peripheral Cutting Balloon microsurgical dilation device (Boston Scienti c) may provide a
unique option to conventional balloon angioplasty. This device features microsurgical blades
called atherotomes mounted on the balloon's surface. As the balloon is expanded, the atherotomes
score and incise the lesion, thereby allowing the balloon to dilate the vessel with less in3ation
pressure. The cutting balloon may have a potential advantage in very resistant brous lesions in
which traditional balloons have a difficult time opening, or in elastic lesions in which elastic recoil
is problematic.
Types of Balloons
Two basic types of balloons are used by interventionalists: (1) high-pressure, relatively
noncompliant, angioplasty-type balloons and (2) low-pressure, compliant balloons, typically
made of latex, silicone, or polyurethane and used primarily for temporary vascular occlusion,
embolectomy, or molding of stent-grafts. High-pressure balloons are made from relatively
noncompliant polymers and are thin walled in design in order for them to be low pro le. Theseballoons exhibit high tensile strength with minimal expansion beyond their nominal diameter as
in3ation pressure is increased. Low-pressure balloons are typically molded into a tubular shape
and then expanded beyond their original size during in3ation. These balloons cannot be in3ated
to precise dimensions and enlarge with increasing in3ation pressure. For angioplasty procedures,
balloons must have a controllable or reproducible nominal diameter to ensure they will not
continue to expand and damage or rupture the target vessel. For example, a low-compliance
highpressure balloon might expand only 5% to 10% when in3ated to its RBP. Conversely,
lowpressure balloons—which are in3ated by volume, not by pressure—can easily be enlarged by
600%.
Peripheral balloon dilation catheters can be divided into four broad categories:
• Standard balloons: 0.035-inch guidewire compatible
• Small vessel balloons: 0.014- to 0.018-inch guidewire compatible
• Large-diameter balloons: 12 mm or larger in diameter
• Other/specialty balloons: cutting, cryoplasty, occlusion, embolectomy, drug-eluting and embolic
capture balloons
These categories are very broad, so there may be some overlap between them. For example, a
standard balloon product line might o0er 12-mm sizes. Peripheral and noncompliant
valvuloplasty balloons range from 12 to 33 mm in diameter and 1.5 to 12 cm in length. Catheter
shaft lengths vary from product to product but generally range from 40 to 150 cm.
Standard Balloons (0.035-Inch)
Standard balloons (0.035-inch guidewire compatible) are used across all types of peripheral
interventional procedures, although 0.014- and 0.018-inch systems have gained popularity in
femoral-popliteal, below-the-knee, renal, visceral, and internal carotid applications. Most
0.035inch balloon catheters are standard over-the-wire systems (Table e5-2).
TABLE e5-2
Commercially Available “Standard” 0.035-Inch Balloons
Diameter Length Catheter Sheath
RBP
Range Range Length Compatibility
(atm)
(mm) (mm) (cm) (French)
Mustang (Boston Scientific, 3-12 20-200 40, 75, 135 5-7 24
Natick, Mass.)
FoxCross (Abbott, Redwood 3-14 20-120 50, 80, 135 5-7 18
City, Calif.)
ATB ADVANCE (Cook, Inc., 4-10 20-80 40, 80, 120 5-8 15
Bloomington, Ind.)
EverCross (ev3, Plymouth, 3-12 20-120 40, 80, 135 5-7 14
Minn.)
OPTA PRO (Cordis 3-12 10-100 80, 110, 5-8 10
Corporation, Miami Lakes, 135
Fla.)
PowerFlex P3 (Cordis) 4-12 10-100 40, 80, 5-8 15110,
Diameter Length Catheter Sheath
RBP135
Range Range Length Compatibility
(atm)PowerFlex Extreme (Cordis) 4-10 20-60 40, 80, 120 5-9 20
(mm) (mm) (cm) (French)
Blue Max 20 (Boston 4-10 20-100 40, 75, 120 6-9 20
Scientific)
Ultra-thin SDS Catheter 4-10 15-80 50, 75, 90, 5-7 16
(Boston Scientific) 135,
150
Ultra-thin Diamond Catheter 3-12 15-100 40, 75, 5-7 15
(Boston Scientific) 120,
135,
150
Synergy (Boston Scientific) 3-12 15-100 50, 75, 90, 5-7 12-6
135,
150
Centurion (C.R. Bard, Inc., 4-10 20-40 50, 75, 120 6-8 20-17
Tempe, Ariz.)
Conquest (Bard) 5-12 20-80 50, 75 6-8 30-20
Opti-Plast XT (Bard) 3-12 15-10 50, 75, 5-8 15-8
100,
120
Dorado (Bard) 3-10 20-200 40, 80, 6-7 24
120,
135
Rival (Bard) 4-10 20-80 80, 135 6-7 14
WorkHorse II 5-10 20-60 50, 75, 100 6-7 18-14
(Angiodynamics,
Queensbury, N.Y.)
AGILTRAC 0.035 Peripheral 4-14 20-100 55, 80, 135 5-7 14-8
Dilation Catheter (Guidant
Corporation, St. Paul,
Minn.)
R B P , Rated burst pressure.
Small Vessel Balloons (0.014 to 0.018 Inch)
Small vessel balloon catheters are for the most part designed to be used with 0.014- to 0.018-inch
guidewires (Tables e5-3 and e5-4). Many of these balloons are rapid-exchange systems, which
improves ease of application. The use of 0.014- to 0.018-inch guidewires and balloons mounted on
smaller catheter shafts affords a smaller crossing profile than their 0.035-inch counterparts.TABLE e5-3
Commercially Available 0.018-Inch Balloons
Diameter Length Catheter Sheath
RBP
Range Range Length Compatibility
(atm)
(mm) (mm) (cm) (French)
Fox SV (Abbott) 2-6 20-120 80, 120, 135 4 22
AGILTRAC .018 4-12 20-60 80, 135 5-7 14
(Guidant)
PowerCross (ev3) 2-6 20-120 90, 150 4-5 14
Slalom (Cordis) 3-8 20, 40 80, 120, 135 4-6 14
SAVVY (Cordis) 2-10 20-100 80, 120, 150 4-5 10
SAVVY Long (Cordis) 2-6 120-220 120, 150 4-5 10
Sterling SL (Boston 2-4 80-150 80,150 4 14
Scientific)
Symmetry (Boston 1.5-6 20-100 90, 135, 150 4-5 15
Scientific)
Talon 0.018 (Boston 4-7 15-40 90, 135 5-6 15
Scientific)
Gazelle 0.018 2-6 20 90, 135 5-6 14
Monorail (Boston
Scientific)
Ultraverse (Bard) 2-9 20-220 75,130 4-6 15
VacuTrak (Bard) 2-7 20-300 140 5-7 12
R B P , Rated burst pressure.TABLE e5-4
Commercially Available 0.014-Inch Balloons
Diameter Length Catheter Sheath
RBP
Range Range Length Compatibility
(atm)
(mm) (mm) (cm) (French)
Sterling ES (Boston 1.5-4 20-40 142-146 4 14
Scientific)
Coyote (Boston 1.5-3 40-220 90-150 4 14
Scientific)
Armada (Abbott) 1.5-4 20-200 90, 150 4 14
NanoCross (ev3) 1.5-4 20-210 90, 150 4 14
SLEEK (Cordis) 2-4 40-220 155 4 16
VIATRAC14 PLUS 4-7 15-40 80, 135 4-5 14
(Abbott)
Amphirion Deep (ev3) 1.5-4 20-120 120 4 14
Aviator (Cordis) 4-7 15-40 142 4-5 14
Ultra-soft SV Monorail 4-7 10-20 90, 150 4-5 14
(Boston Scientific)
Advance 14LP (Cook 2-4 20-200 170 4 12
Medical)
R B P , Rated burst pressure.
Large Vessel Balloons (0.035 Inch)
Large-diameter balloons range from 12 to 33 mm (Table e5-5). They are all 0.035-inch,
over-thewire systems. These balloons are used in a wide variety of procedures ranging from vascular
(venous, aortic, valvular) to gastrointestinal (esophageal, colonic, duodenal) interventions. With
balloons of this size, various factors such as in3ation/de3ation times, puncture resistance, sheath
size, RBP (which is usually low), and balloon taper become important. Many of the
largerdiameter balloons are made of nylon derivatives and can therefore be used to mount
balloonexpandable stents (e.g., large Palmaz stents, Models 3110 and 4010 [Cordis Endovascular, Miami
Lakes, Fla.]).TABLE e5-5
Commercially Available Large-Diameter Balloons
Diameter Length Catheter Sheath
RBP
Range Range Length Compatibility
(atm)
(mm) (mm) (cm) (French)
Atlas (Bard) 12-26 20-60 75-120 7-12 18
Impact (B. Braun, 12-25 20-40 75, 120 8-14 10
Bethlehem, Pa.)*
XXL (Boston 12-18 20-60 75, 120 8 10
Scientific)
Maxi LD (Cordis) 14-25 20-80 80, 110 8-12 6
Z-med (B. Braun)* 10-25 40 100 7-12 9
Z-med II (B. Braun)* 5-25 20-50 100 6-14 15
R B P , Rated burst pressure.
*Additional sizes are available by special order.
Other Balloons
Peripheral Cutting Balloon (Boston Scientific)
To overcome the “hoop stress” encountered when dilating resistant lesions, angioplasty balloons
must be in3ated to high pressure, but high in3ation pressure can result in extensive barotrauma to
the dilated vessel segment. The Peripheral Cutting Balloon features a noncompliant balloon with
four atherotomes mounted longitudinally on its outer surface (Table e5-6). These atherotomes are
protected in recesses of the balloon material when the balloon is de3ated. The Peripheral Cutting
Balloon is delivered to the target lesions via a guiding catheter or sheath. Once positioned within
the lesion, the balloon is uncovered by retracting the guiding catheter or sheath. As the Peripheral
Cutting Balloon device is in3ated, the dilation force is focused at the edges of the atherotomes.
The atherotomes “score” the plaque, and full balloon in3ation can now occur at lower pressure,
which in theory reduces the barotrauma associated with balloon angioplasty.


TABLE e5-6
Specialty Balloons
Catheter
Diameter Sheath
Length RBP (Volume
Range Compatibility
Range or atm)
(mm) (French)
(cm)
Peripheral Cutting Balloon 5-8 50, 90, 135 7 10 atm
(Boston Scientific)
(0.018inch)
PolarCath (Boston Scientific) 2.5-8 80, 120, 135 5-8 8 atm (device
(2.5-4 mm [0.014 inch], 4- controlled)
8 mm [0.035 inch])
PROTEUS (Angioslide) 5-6 110, 135 6-7 12
ClearWay OTW (Atrium, 4-6 40, 80, 90, 7 N/A
Hudson, N.H.) 140
ClearWay RX (Atrium) 1-4 134 8 N/A
R B P , Rated burst pressure.
The Peripheral Cutting Balloon is made of PET and has a nominal in3ation pressure of 6 atm
and an RBP of 10 atm. The Peripheral Cutting Balloon is available in diameters of 2 to 8 mm with
lengths of 10 and 20 mm. It is designed to be used with 0.018-inch guidewires.
VascuTrak PTA Dilatation Catheter (Bard Peripheral Vascular)
The VascuTrak, in contrast to the Boston Scienti c cutting balloon, is a semicompliant balloon
with two external wires designed to deliver force along the length of the balloon. This balloon is
available in lengths up to 300 cm, allowing it to be used to treat long, di0use lesions and for
dilation at low in3ation pressures. This low in3ation pressure angioplasty potentially reduces
balloon-induced overdilation of the vessel and offers controlled plaque modification.
PolarCath Peripheral Dilatation Catheter (Boston Scientific)
The PolarCath peripheral balloon catheter is an angioplasty system that simultaneously dilates
and cools the plaque and vessel wall in the area of treatment. Cooling is achieved by in3ating the
balloon with nitrous oxide rather than the usual saline/contrast mixture. It is believed that cooling
to −10°C induces apoptosis in the treated smooth muscle cells. This nonin3ammatory form of cell
death may lead to several potentially bene cial e0ects, including decreased elastic recoil and
constrictive remodeling and reduced neointimal hyperplasia. However, these theoretical bene ts
have yet to be proved.
The PolarCath system consists of three components: a disposable handheld
microprocessorcontrolled in3ation unit, a balloon dilation catheter with dual coaxial balloons, and a cartridge of
liquid nitrous oxide. Nitrous oxide is used to in3ate and chill the balloon and expose the vessel
wall to a predetermined algorithm of temperature (−10°C), pressure (8 atm), and dwell time (25
seconds). The latest generation of the PolarCath in3ation unit is programmed to in3ate the
balloon in a stepped manner in 2-atm increments until the nominal pressure is achieved. The
balloon is positioned at the site of the arterial narrowing. After pressing the start button, the



liquid nitrous oxide leaves the cartridge and travels through the catheter to the balloon. The liquid
changes to a gas and causes a signi cant reduction in temperature while the balloon is expanded.
At the completion of the cycle, the gas is evacuated, the balloon is de3ated, and the vessel returns
to its baseline temperature of 37°C. Each dilation cycle takes less than 1 minute. Multiple dilations
can be performed with each system; however, the liquid nitrous oxide cartridge must be changed
between inflations.
The resultant theoretical potential bene cial e0ects of cryoplasty (which have yet to be proved)
are threefold: (1) Altering the plaque response with controlled plaque fracture—microfractures weaken
plaque and may result in more uniform blood vessel dilation. Uniform dilation may prevent
formation of large tears deep into the wall of the vessel that can occur with standard angioplasty
and result in extensive dissection. (2) Reducing vessel wall recoil—the freeze-induced alteration in
the morphology of collagen and elastin bers may result in short-term loss of vessel elasticity.
This loss of vessel elasticity may reduce postdilation elastic recoil and help optimize the initial
angiographic result, thereby possibly reducing the need for a stent. Without a stent, the cell
proliferation associated with the foreign body immune response may be eliminated. (3)
Apoptosis—on a cellular level, osmotic forces in the presence of ice cause smooth muscle cells to
eject water. The process of dehydration and subsequent rehydration triggers a nonin3ammatory
programmed cell death. Apoptosis of the targeted cells may lead to a reduction in neointimal
formation and collagen synthesis, which could possibly provide protection against constrictive
remodeling and restenosis. Furthermore, it may not interfere with or delay re-endothelialization.
Occlusion Balloons
Typically made of semicompliant polyurethane, latex, or silicone materials, these large balloons
(20-46 mm) are now most commonly used to mold aortic stent grafts. The design of these balloons
varies from a simple spherical shape to a trilobed shape (i.e., Trilobed Balloon, W.L. Gore,
Flagsta0, Ariz.) (Table e5-7). Smaller occlusion balloon catheters (8.5-13.0 mm in diameter
[Boston Scienti c]) have been used during interventional procedures to prevent re3ux of embolic
material or to minimize antegrade blood 3ow during embolization procedures (i.e., alcohol
embolization of renal cell cancer or arteriovenous malformations [AVMs]). Balloon-occlusion
catheters are essentially catheters with a compliant balloon at their end. Most balloons have a
port for in3ation that is independent of the coaxial port to the inner lumen of the catheter. Some
balloons of balloon-occlusion catheters, when fully in3ated, cover the catheter tip; in other words
the catheter tip invaginates into the balloon and does not stick out. This is important when
choosing balloon-occlusion catheters for vascular beds that are tortuous with tight sharp turns,
where a protruding catheter tip maybe traumatic to the target vascular bed. Balloon catheters for
test occlusion are also available for carotid applications but are not discussed in this chapter.
TABLE e5-7
Commercially Available Balloon-Occlusion Catheters
Balloon- Shaft Balloon
Sheath ID
Occlusion Manufacturer Material Length Diameter
(French) (inches)
Catheter (cm) (mm)
Wedge Arrow Latex 5 60, 110 6.5 0.021
Pressure International
5 60, 110 8 0.025
Catheter6 60, 90, 10 0.035
Balloon- Shaft Balloon
Sheath ID110
Occlusion Manufacturer Material Length Diameter7 110 11 0.038(French) (inches)
Catheter (cm) (mm)
8 110 11 0.038
OTW (Edwards Life 5 40, 80 9 0.025
Fogarty Sciences,
6 40, 80 11 0.035
Irving,
7 40, 80 13 0.035Calif.)
8 80 14 0.038
Occlusion Boston Scientific Latex 8 (9*) 65, 80, 11.5 0.038
Balloon 100
Equalizer 14 65, 100 20 0.038
14 65, 100 27 0.038
16 65, 100 33 0.038
Venotomy 65, 100 40 0.038
Arteriotomy
Python Applied Medical Syntel 6 40, 80 5 0.035
6 40, 80 9 0.038
6 40, 80 11 0.038
6 40, 80 13 0.038
6 80 14 0.038
Flow- Cook Corp. Latex 6 80 10 0.035
Directed
Balloon
32-CODA Polyurethane 12 120 32 0.038
40-CODA 12 120 40 0.038
Reliant Medtronic Polyurethane 12 100 46 0.038
Q50 W.L. Gore Polyurethane 9 (12*) 65, 100 50 0.038
*Denotes actual size and not manufacturer recommendations.
Perhaps the oldest technical application of balloon-occlusion catheters is their utilization in
mechanical embolectomy and thrombectomy. Invented by Thomas J. Fogarty more than 30 years
ago, embolectomy balloon catheters are used for removal of fresh emboli and thrombi from blood
vessels and grafts (see Table 5-7). Several types of embolectomy catheters are available for use
with or without a guidewire. These balloon embolectomy catheters feature a pliable tip that helps
avoid plaque avulsion and minimizes trauma to venous valves and the vessel itself. The
over-thewire Fogarty balloon (Edwards Life Sciences, Irvine, Calif.) can provide enhanced trackability
through occluded, tortuous, or stenotic vessels.
Moreover, balloon-occlusion catheters can be used to occlude or temper arterial or venous 3ow




for diagnostic or therapeutic purposes. They can be used as a temporary test vascular occlusion to
evaluate the hemodynamic e0ect of vascular occlusion prior to a de nitive occlusion
(embolization), or to obtain manometry pressure reading. The most common example is the use of
balloon-occlusion catheters for “wedge” hepatic pressures and hepatic carbon dioxide
portography. Not uncommonly, balloon-occlusion catheters are used to temper 3ow in a vessel to
help achieve occlusion or sclerosis of a target vascular bed. Sclerosants used in combination with
balloon-occlusion catheters are nonadhesive sclerosants such as absolute alcohol, 50% dextrose
(D50), Sotradecol, or Onyx (Covidien, Mans eld, Mass.) and adhesive sclerosants such as
cyanoacrylate and histoacryl. Vascular beds/procedures that commonly require balloon-occlusion
catheters include high-3ow vascular malformations (typically in the pelvis and shoulder girdle),
gastric varices (in balloon-occluded retrograde transvenous obliteration procedures), and
refractory pelvic congestion syndromes. Microcatheters may be used to help distribute sclerosants
and embolic material beyond (distal or proximal relative to 3ow) the balloon-occlusion catheter.
Microcatheters are also used to selectively catheterize vessels within the blood 3ow–tempered
target vascular bed. The microcatheter can be passed coaxially through the balloon-occlusion
catheter (compatibility with the inner diameter of the balloon-occlusion catheter [see Table e5-7]
is required) or adjacent to the balloon of the balloon-occlusion catheter. Table e5-7 demonstrates
many of the commercially available balloon-occlusion catheters and their specifications.
Drug-Eluting Balloons
Scheller et al. in 2003 rst described the application of drug-eluting balloons (DEBs) to deliver
10drugs such as paclitaxel during angioplasty. Clinical trials (PACCOCATH [Bayer AG, Germany]
ISR I and II) validated the eL cacy of paclitaxel-coated balloon catheters to treat coronary in-stent
11restenosis. Recently, coronary data have accelerated interest in using DEBs in the periphery,
particularly in below-the-knee interventions where restenosis rates are high. Clinical trials such as
the Thunder Trial (Local Taxan with Short Time Exposure for Reduction of Restenosis in Distal
Arteries) in 2004 were initiated to evaluate use of commercially available DEBs in treating
occlusive disease of the super cial femoral artery. Cook Medical (Bloomington, Ind.) has released
the Advance 18 PTX line of balloons in Europe. Invatec (Roncadelle, Italy), with its In.Pact
Amphirion line of DEBs, has joined several other manufacturers in this eld. Although these
balloons are widely available in Europe and carry European Union CE marking (Conformité
Européene, meaning “European Conformity”), DEB trials are only beginning in the United States
at the time of this publication.
Atrium Medical (Hudson, N.H.), produces a 0.014- and 0.035-inch line of rapid-exchange and
over-the-wire balloons that have thin, microporous polytetra3uoroethylene (PTFE) balloons. This
porous membrane allows drugs to be infused directly into targeted areas while blood 3ow is
occluded.
Embolic Capture Balloon
Angioslide (Caesarea, Israel) has developed the PROTEUS balloon catheter, which is a PTA
balloon catheter with an embolic capture and containment feature. The device is an over-the-wire
double-lumen catheter with a foldable balloon located near the distal atraumatic soft tip. The
system uniquely combines the ability to perform both angioplasty and embolic debris capture in a
single integrated device. The debris capture function reduces the distal release of embolic particles
that could otherwise potentially cause distal embolization. The device functions as a normal
angioplasty balloon: the balloon is semicompliant and is in3ated to a nominal pressure of 8 atm.


After angioplasty, the balloon is de3ated to 2 atm. At this point, arterial 3ow remains occluded,
and the balloon is then folded inward, creating a cavity that captures embolic particles. The
folding mechanism pulls potentially embolic debris into the capture cavity of the balloon as it is
folded. PROTEUS capture eL ciency has been compared to lter-based embolic protection systems
during regulatory trials.
Summary
Balloon catheter technology has made remarkable strides over the past 3 decades. The goal of
attaining low-pro le systems with excellent trackability, rapid in3ation/de3ation times,
noncompliance, and scratch resistance is quickly being met. There are now a large variety of
balloons with higher burst pressures, smaller diameters, and low pro les that allow interventions
in peripheral vessels as small as 2 mm. As it stands today, interventionalists have a wide
assortment of balloon catheters to facilitate interventions (critical limb ischemia, intracranial
procedures, esophageal intervention, etc.) not possible just a few years ago. Future advancements
12may see balloons combined with light therapy (lasers) and drug delivery systems or further
integration with cutting blades, thermal energy, biodegradable stents, and other products.
Key Points
• The dilating force generated by an angioplasty balloon is directly proportional to the
balloon's diameter and inflation pressure.
• Longer balloons and larger vessels will rupture at lower balloon inflation pressures.
• Balloon compliance is a measure of how much a balloon continues to expand beyond
its minimal diameter with increasing balloon inflation pressure.
• A compliant balloon may deform in a resistant lesion and inadequately dilate the
lesion.
• Not all balloon materials have the same compliance characteristics.
• Monorail balloon catheters allow the use of shorter-length guidewires.
References
1. Dotter, CT, Judkins, MP. Transluminal treatment of arteriosclerotic obstruction.
Circulation. 1964; 30:654–670.
2. Grüntzig, A. Die Perkutane Rekanalization chronischer arterieller Verschlüsse
(DotterPrinzip) mit einem neuen dilations Katheter. Rofo Fortschr Geb Rontgtenstr Neuen Bildgeb
Verfahr. 1976; 1214:80–86.
3. Abele, JE. Balloon catheters and transluminal dilatation: Technical considerations. AJR
Am J Roentgenol. 1980; 135:901–906.
4. Matsumoto, AH, Barth, KH, Selby, JB, Jr., Tegtmeyer, CJ. Peripheral angioplasty balloon
technology. Cardiovasc Intervent Radiol. 1993; 16:135–143.
5. Zollikofer, CL, Cragg, AH, Hunter, DW, et al. Mechanism of transluminal angioplasty. In:
Castaneda-Zuniga WR, Tadavarthy SM, eds. Interventional radiology. Baltimore: Williams &
Wilkins; 1988:236–265.
6. Gerlock, AJ, Regen, DM, Shaff, MI. An examination of the physical characteristics leading
to angioplasty balloon rupture. Radiology. 1982; 144:421–422.7. Matsumoto, AH, Barth, KH. Balloon angioplasty technology. In: Maynar-Moliner M,
Castaneda-Zminga W, Joffre F, Zollikofer CL, eds. Percutaneous revascularization techniques.
New York: Thieme; 1993:36–40.
8. Olbert, F, Hanecka, L. Transluminal vascular dilation with a modified dilation catheter.
In: Zietler E, Grüntzig A, Schoop W, eds. Percutaneous vascular recanalization. Berlin:
Springer-Verlag; 1978:32–38.
9. Tegtmeyer, CJ. Guide wire angioplasty balloon catheter: Preliminary report. Radiology.
1988; 159:253–254.
10. Scheller, B, Speck, U, Abramjuk, C, et al. Paclitaxel balloon coating, a novel method for
prevention and therapy of restenosis. Circulation. 2004; 110:810–814.
11. Scheller, B, Hehrlein, C, Bocksch, W, et al. Two year follow-up after treatment of coronary
in-stent restenosis with a paclitaxel-coated balloon catheter. Clin Res Cardiol. 2008;
97:773–781.
12. Saab M. High-Pressure medical balloons expanding the design options. Medical Device &
Diagnostic Industry, September 2000. p. 86.C H A P T E R 6
Stents
Gregory J. Dubel and Timothy P. Murphy
Clinical Relevance
Stents have revolutionized endovascular management of peripheral arterial disease and been responsible for the transition in
revascularization from surgery to interventional means for many vascular territories, including coronary, subclavian, aortoiliac, carotid,
renal, and visceral arteries. They may eventually be the preferred therapy for femoropopliteal obstruction. The impact of stents on clinical
practice has been enormous. By understanding the basic biological, mechanical, and design properties of these devices, the practitioner is
better able to select the appropriate device for individual applications.
Introduction
Stents and stent-grafts have a variety of applications for image-guided interventions, including both vascular and nonvascular uses. Many
stents marketed in the United States are U.S. Food and Drug Administration (FDA) approved for treating biliary or tracheobronchial stenoses,
although recently more have gained FDA approval for intravascular use (Tables e6-1, e6-2, and e6-3; also see discussions of individual stents).
TABLE e6-1
Balloon-Expandable (BX) Stents
Minimum Stent Stent
FDA Maximum
Device Company Name Critical Features Metal Introducer Diam.
Indication wire (in)
(F) (mm)
Assurant Cobalt Medtronic Inc. Iliac, Biliary High strength/radiopacity, CoCr 6 0.035 6-8 20, 30, 40,
minimal foreshortening, mod
flexibility, fused module design,
9-10 30, 40, 60
smaller cells
Express Iliac LD Boston Scientific Iliac, Biliary Mod strength, min foreshortening, 316 L-SS 6 0.035 5-8 17, 27, 37
flexible, micro/macro modules
7 0.035 8 57
assist conformability
7 0.035 9, 10 25, 37, 57
Express Renal Boston Scientific Renal, biliary Low-profile version of Express 316 L-SS 5 0.018 4, 5 15, 19
SD with similar attributes
5 0.018 6 14, 18
6 0.018 7 15, 19
Formula 414 Cook Medical Biliary Mod strength/radiopacity, no 316 L-SS 5,6 0.014 (414 3-8 12, 16, 20,
RX/Formula foreshortening, low-profile on RX)
418 par w/Cobalt designs, min 0.018
balloon overhang (418)
IntraStent ev3/Covidien Biliary Mod-high radial 316 L-SS 8 Unmounted 9-12 16, 26, 36,
Double Strut strength/radiopacity, mod-high
LD flexibility, no foreshortening,
open-cell
IntraStent Mega ev3/Covidien Biliary Mod-high radial 316 L-SS 9 Unmounted 9-12 16, 26, 36
LD strength/radiopacity, mod
flexibility, no foreshortening,
open-cell
IntraStent Max ev3/Covidien Biliary High radial strength/radiopacity, 316 L-SS 11 Unmounted 12 16, 26, 36
LD moderate flexibility, no
foreshortening, open-cell
Palmaz (M, L, Cordis Iliac (L), High strength/radiopacity, closed- 316 L-SS 6, 7 (M) Unmounted 4-8 10, 15, 20,
or XL) Endovascular Iliac/Renal cell design, variable
(M), foreshortening, can be
Biliary overdilated, poor flexibility,
(XL) unmounted stents require
8-12 (L) 8-12 30
crimper from manufacturer
10-12 (XL) Unmounted 10 (over 30, 40, 50dil
Minimum Stent Stent
FDA Maximum
14Device Company Name Critical Features Metal Introducer Diam.
Indication wire (in) 26)
(F) (mm)Palmaz Blue Cordis Biliary As per Palmaz Blue with monorail CoCr alloy 5 0.014 5-6 15, 18
Endovascular delivery (L605)
Increased 5 0.018 4-7 12, 15, 18,
strength/flexibility/radiopacity,
decreased metal surface area,
increased cell size compared
with Genesis, improved MRA
Palmaz Genesis Cordis Biliary As per Genesis with monorail 316 L-SS 4-6 0.014 4-7 12, 15, 18,
Endovascular delivery
Strength near Palmaz, more 5, 6 0.018 3-8 12, 15, 18,
flexible/conformable/trackable,
less foreshortening, closed cell,
proprietary nesting on balloon,
6,7 0.035 4-10 12, 15, 18,
final length dependent upon
dilation diameter
Palmaz Genesis Biliary As per Genesis, unmounted, 316 L-SS 6 Unmounted 5-8 12, 15, 18,
(unmounted) requires manufacturer crimper 7-7.5 5-10

8 10-
12
ParaMount ev3/Covidien Biliary Tantalum markers at end, low- 316 L-SS 5 0.014, 0.018 5, 6 14, 18, 21
Mini GPS profile, minimal 6 7
foreshortening, open small
cells, conformable, flexible,
zero balloon overhang
Visi-Pro ev3/Covidien Biliary Tantalum markers at end, no 316 L-SS 6 0.035 5-8 12 (ex
foreshortening, low-profile,
open small cells, conformable,
flexible, zero balloon overhang
7 0.035 9-10 17, 27, 37,
Racer Medtronic Inc. Biliary Mod-high strength, more Co alloy 5, 6 0.014, 0.018 4-7 12, 18
flexible/conformable/trackable, (MP35N)
min foreshortening, small cells,
proprietary stent retention
system, improved MRA
RX Herculink Abbott Vascular Renal, biliary Mod-high strength/radiopacity, CoCr 5 0.018 4, 4.5, 12 (ex
Elite mod-high flexibility, open small 5,
cell, low foreshortening, stent 5.5,
retention system, monorail 6,
6.5,
7
Omnilink Abbott Vascular Biliary Mod strength/radiopacity, mod- 316 L SS 5, 6, 7, 8 0.018 4-10 18, 28, 38,
high flexibility, low
foreshortening, small cells, can
5, 6, 7, 8 0.035 5-10 12, 16, 18,be overdilated
Valeo Bard Peripheral Biliary Mod radial strength and 316 L SS 6 0.035 6,7,8 18, 26, 36,
Vascular radiopacity, flexible, open cell 7 0.035 9,10Minimum Stent Stent
FDA Maximum
Device Company Name Critical Features Metal Introducer Diam.
Indication wire (in)TABLE e6-2
(F) (mm)
Self-Expandable (SX) Stents
Delivery
Min Max Stent Stent
Device Manufacturer FDA Indication Critical Features Metal Introducer wire Diameter Length
(OD) (F) (in) (mm) (mm)
Rx Acculink Abbott Vascular Carotid Monorail, small Nitinol 6 0.014 5-10 20, 30, 40 126
cells/good straight
scaffolding, fixed
6-8, 7-10 30, 40
handle deployment,
taper
for use with Accunet
EPS
Absolute Pro Abbott Vascular Biliary Injectable triaxial Nitinol 6 0.035 5-10 20, 30, 80, 135
delivery catheter, 40, 60,
platinum markers at 80,
ends 100
Complete SE Medtronic Inc. Iliac Open small cells, Nitinol 6 0.035 6-10 20, 40, 80, 120
tantalum markers at 60, 80,
ends 100
Iliac, biliary Nitinol 6 0.035 4-10 20-150 120
Supera IDEV Biliary Woven, highly flexible, Nitinol 6 0.035 4-8 40, 60, 120
Veritas Technologies conformable, closed 80,
cell 100,
120
Dynalink Guidant Biliary Mod size open cells, Nitinol 6 0.018 5-10 28, 38, 56, 80, 120
highly conformable, 80,
fixed handle 100
deployment
LifeStent Bard Peripheral SFA/prox pop Small open-cell design, Nitinol 6 0.035 6-7 20, 30, 80, 130
Vascular Vascular platinum markers, 0.035 6-7 40, 60,
LifeStent rotating knob 0.035 6-7 80,
XL delivery catheter 100,
LifeStent As LifeStent but with 120,
Solo ratchet handle 150,
delivery system 170
200
E·Luminexx Bard Peripheral Iliac, biliary Small cell size, large Nitinol 6 0.035 7-10 20, 30, 80, 135
Vascular welded Ta markers, 40, 50,
enhanced 60, 80,
electropolishing, 100
ratchet delivery
Neuroform Boston Scientific HDE wide-neck Designed for Nitinol 5 0.014 2.5, 3, 3.5, 10, 15, 20,
intracranial intracranial/small- 4, 4.5 30
aneurysms vessel use, min
foreshortening,
highly conformable,
Humanitarian Device
Exemption (HDE)
Precise Cordis Biliary OTW, low-profile Nitinol 6 0.018 5-10 20, 30, 40 135
Endovascular S.M.A.R.T.,
extremely
flexible/conformable,
segmented
Precise RX Cordis Biliary Monorail version of Nitinol 5 0.014 5-7 20, 30, 40 135Endovascular Precise 6 0.014 8-10 20, 30, 40 135
Delivery
Min Max Stent Stent
Precise Cordis Carotid OTW, autotapering, use Nitinol 5.5 0.018 5-8 20, 30, 40 135
Device Manufacturer FDA Indication Critical Features Metal Introducer wire Diameter Length
Carotid Endovascular with Emboshield EPS 6 0.018 9-10 20, 30,
(OD) (F) (in) (mm) (mm)
40
Precise Pro Cordis Carotid Monorail, autotapering, Nitinol 5 0.014 5-18 20, 30, 40 135
RX Endovascular use with Emboshield
EPS
6 0.014 9-10 20, 30, 40 135
Protege GPS ev3/Covidien Biliary Flexible, retention lock Nitinol 6 0.018 6-10 20, 30, 135
prevents stent 40, 60,
jumping, tantalum 80
markers at ends, zero
6 0.035 9, 10, 12, 20, 30, 80, 120
foreshortening
14 40, 60,
80
Protege ev3/Covidien Biliary As per Protege GPS with Nitinol 6 0.035 5-8 20, 30, 80, 120
EverFlex added flexibility 40, 60,
80,
100,
120,
150
(150
not
avail
in
5 mm)
Protege ev3/Covidien Biliary Large-diameter version Nitinol 6 0.035 9-14 20, 30, 80, 120
BIGGS of Protege EverFlex 40, 60,
80
Protege RX ev3/Covidien Carotid Carotid version of Nitinol 6 0.018 6-10 20, 30, n/a
Protege, monorail, straight 40, 60
use w/SpiderFX EPS
6 0.018 6-8, 7-10 30, 40 n/a
taper
Sentinol Boston Scientific Biliary Variable cell size, Nitinol 6 0.035 5-10 20, 40, 75, 135
platinum markers, 60, 80,
proprietary surface
prep to decrease
corrosion
S.M.A.R.T. Cordis Biliary Small cell size, highly Nitinol 7 0.035 6-8 120, 150 120
Endovascular conformable,
segmented
S.M.A.R.T. Cordis Biliary As per S.M.A.R.T. plus Nitinol 6 0.035 9-10 30, 40, 80, 120
Control Endovascular coined tantalum 60, 80
markers, w/thumb
screw delivery 7 0.035 12-14 30, 40, 80, 120
system 60, 80
Iliac 6 0.035 6, 7, 8 20, 30, 80, 120
40, 60,
80,
100
6 0.035 9, 10 20, 30, 80, 120
40, 60
Symphony Boston Scientific Biliary Hexagonal, large cells Nitinol 7 0.035 5-8, 10, 12, 20, 22, 23, 75, 110
from shaped nitinol 14 40, 44,
wire, less flexible, 60
mod hoop strength,
platinum markers
Wallstent Boston Scientific Carotid Braided, foreshortens, Elgiloy 5-6 0.014 6, 8, 10 21, 22, 135
(various Iliac use with FilterWire 24, 29,
designs) Venous EPS 36, 37
BiliaryTracheobronchial Braided, high 6 0.035 6-10 18-69 100, 160
Delivery
Min Max Stent StentTIPS flexible/scaffolding, various
6-10 0.035 10, 12, 14, 20, 40, 75Device Manufacturer FDA Indication Critical Features Metal Introducer wire Diameter Lengthclosed-cell, 20%-50%
16 42, 60,(OD) (F) (in) (mm) (mm)foreshortening,
68, 90,reconstrainable,
94
multiple designs
(iliac, biliary, etc.) 6-9 0.035 8, 10, 12 20, 40, 75
42, 60,
68, 90,
94
6-12 0.035 5-24 20-94 135
various various
7-9 0.035 10, 12 40, 42, 75
60, 68,
90, 94
Xact Abbot Vascular Carotid Monorail, closed cell, Nitinol 6 0.014 7-10 20, 30 135
straight and tapered straight
styles, use
0.014 6-8, 7-9, 8- 30, 40
w/Emboshield
10 taper
Xceed Abbott Vascular Biliary Small cell size, highly Nitinol 6 0.035 5-8 20, 30, 80, 120
conformable, coined 40, 60,
radiopaque markers 80
Xpert Abbott Vascular Biliary Very low profile, highly Nitinol 4 0.018 3-6 20, 30, 80, 120
open cell, low 40, 60
chronic outward
Nitinol 5 0.018 8 30, 40, 60 80, 120
force, small vessel
applications
Zilver 518 Cook Medical IliacBiliary Small, open cell design, Nitinol 5 0.018 6-10 20, 30, 125
Zilver 518 gold markers, no 40, 60,
Nitinol 5 0.018 6-10 125
RX foreshortening 80
Nitinol 6 0.035 6-10 80, 125Zilver 635
Zilver 635 Nitinol 6 0.035 4, 5, 12, 14 80, 125
Biliary
Enterprise Codman Wide-neck Closed-cell, one-time Nitinol via n/a 4.5 14, 22, 135
Neurovascular intracranial recapture, microcath 28, 37
aneurysms radiopaque markers >0.021
at ends of stent ID
Wingspan Boston Scientific HDE for intracranial Open-cell, flexible, Nitinol 5 0.014 2.5, 3, 3.5, 9, 15, 20 131
atherosclerotic radiopaque markers 4, 4.5
disease at ends, HDETABLE e6-3
Peripheral Stent-Grafts
Max Device Device
Company Introducer
Device FDA Indication Critical Features Construction wire Diameter Length
Name Size (F)
(in) (mm) (mm)
aSpire Vascular Biliary Flexible, mod ePTFE-covered 7 0.018 6 -9 25, 50,
Architects foreshortening, helically 8 0.035 6-10, 12 100,
Vascular reconstrainable, shaped 150
Architects tantalum markers, nitinol 25,
side-branch patency ribbon 50,
100,
150
Fluency Plus Bard Tracheobronchial Flexible, min Nitinol 8-9 0.035 6-10 40, 60,
Peripheral foreshortening, low w/internal 80
Vascular profile, tantalum and external
markers layer ePTFE
Flair Bard AV hemodialysis Flared end, flexible, min Nitinol 9 0.035 6-9 30, 40,
Peripheral Grafts foreshortening, low w/internal 50
Vascular profile, tantalum and external
markers layer ePTFE
iCast/Advanta Atrium Tracheobronchial Balloon-expandable, 316 L-SS 6 0.035 5-9 16, 22,
Medical min foreshortening, balloon- 38,
small delivery sheath expandable 59
stent
7 0.035 10,12 38, 59
encapsulated
w/ePTFE
Viabahn W.L. Gore & SFA, iliac, Min foreshortening, ePTFE 6 0.018 5-6 25, 50,
Associates tracheobronchial flexible/conformable, externally 100,
must be covered supported 150
w/sheath, heparin with nitinol
7 0.018 7-8
coating wire
11-12 0.035 9-11, 13 25, 50,
100,
150
Viabil W.L. Gore & Biliary Biliary use, proximal ePTFE 10 0.035 8, 10 40, 60,
Associates anchors, w or w/o externally 80,
drainage holes supported 100
with nitinol
wire
Viatorr W.L. Gore & TIPS A 2-cm uncovered portal Dual-layer 10 0.038 8,10,12 60, 70,
Associates end, markers at ePTFE 80,
hepatic end, and externally 90,
junction supported 100
uncovered/covered with nitinol
wire
Wallgraft Boston Tracheobronchial, Reconstrainable, 20%- Braided Elgiloy 9-12 0.035 6-12 20, 30,
Scientific biliary 50% foreshortening, filaments 50,
non-flared ends covered w/ 70
PET
Many factors inGuence stent design and placement considerations. These may be divided into biological and technical factors. In the “real
world” of daily patient care, technical factors (e.g., flexibility, radiopacity, sizing, etc.) tend to dominate one's choice of stent. However, it has
been speculated (but not proven) that host reaction and the biology of the stent may be the most important factors determining long-term
patency. For this reason, it is useful to have a basic understanding of the interplay between stent and vessel.
In Vivo Performance Characteristics
Immediately following stent placement, the metal surface is exposed to circulating blood, and the cascade of events leading to tissue
1incorporation begins. Plasma proteins (i.e., Kbrinogen) are initially deposited on the surface of the stent, quickly followed by platelets and
white blood cells. Within days to a few weeks, this layer will be replaced by a neointima composed of Kbromuscular material and some
endothelial cells. This sequence of events is depicted in Figure e6-1. This replacement occurs Krst around stent struts and then expandseccentrically. Histologic studies have also demonstrated progressive thinning of the media that may contribute to maintenance of the arterial
1,2luminal diameter. Over time, the neointima is further replaced by collagen with scattered smooth muscle cells and a variable number of
endothelial cells on the surface. For reasons that remain unclear, some patients develop an aggressive neointimal (especially smooth muscle
cell) proliferation that results in compromise of the luminal diameter. The intimal proliferative response is highly variable in the various
3 4vascular beds where stents are placed, is variable between stents, and is eLected by the surface characteristics of the stent. Prevention of
5-8this response is an area of active research and one of the main benefits of drug-eluting stents in the coronary circulation.
FIGURE E6-1 Normal sequence of events after placement of metallic stent in a blood vessel. Note that thickness of
tissue deposited on surface of prosthesis is not on a linear scale. Vertical wavy lines represent strands of fibrinogen.
Horizontal wavy lines represent fibrinogen strands oriented in direction of flow. Parallel lines represent collagen and ground
substance. nm, Nanometers; nv, neovessel. (Adapted from Palmaz JC. Intravascular stents: tissue-stent interactions and
design considerations. AJR Am J Roentgenol 1993;160:613–8.)
Biocompatibility and corrosion resistance are also related to stent surface properties. Stents currently available are manufactured from
highly biocompatible materials including 316 L stainless steel (316 L-SS), cobalt-chromium alloys (CoCr), Elgiloy (SS-cobalt alloy), nitinol
(nickel-titanium alloy), and platinum. Because surface smoothness aLects thrombogenicity and corrosion resistance, stents undergo polishing.
Mechanical polishing (i.e., grinding, milling, or buMng) improves smoothness but is inferior to electropolishing. Electropolishing results in
superior surface smoothness and uniformity, improves the formation of an oxide layer on the surface (CrO or TiO ), and improves corrosion2 2
resistance. Corrosion of a stent can lead to breakdown of the metal (Fig. e6-2) or increased host reaction, either of which may decrease
patency.FIGURE E6-2 The benefits of electropolishing on metals. Top, Heavily corroded mechanically polished nitinol explant (5
months). Bottom, Nitinol explant (12 months) with electropolished surface with tantalum marker attached. (From Stoeckel
D, Pelton A, Duerig T. Self-expanding nitinol stents: material and design considerations. Eur Radiol 2004;14:292–301.
Reprinted with permission from Springer Science and Business Media.)
Stent Designs
The two fundamentally diLerent classes of stent include self-expanding (SX) and balloon-expandable (BX) stents. BX stents require balloon
dilation to increase their diameter from the compressed state. SX stents will attempt to regain diameter upon deployment. Many SX stents
marketed today are made of nitinol. Nitinol exhibits shape memory, a property that allows it to regain a prescribed shape when released from
a compressed state. SX braided stents, such as the Elgiloy Wallstent, rely on a woven spring-type design that expands in diameter when
released from a compressed state (Fig. e6-3).
FIGURE E6-3 How stent design affects expansion, foreshortening, and metal surface area. Top to bottom,
Selfexpanding Symphony Stent (7 × 40 mm), self-expanding Wallstent (7 × 40 mm), and balloon-expandable Palmaz stent
(P394 inflated to 7 mm). Stents with larger cell size (e.g., Symphony) will generally have lower metal surface area. Note
large variation in amount of foreshortening between stents. Also note that all three have closed-cell geometry. (Courtesy
Boston Scientific, Natick, Mass.)9Stent architecture is another useful concept in contrasting diLerent stents. There are many variations in the terminology used in this area
owing to a lack of standardization. The basic concepts are delineated in Figure e6-4. For the purposes of this chapter, an attempt will be
made to use terminology in a uniform fashion to facilitate comparisons between stents. The cell of a stent refers to the polygonal space
bordered by metallic supports. The metallic supports that deKne the cells are referred to as struts. Hinges are specialized struts that connect
crowns or adjacent struts and are often designed to improve longitudinal Gexibility by incorporating U-shape, spiral, and other nonlinear
shapes (see Fig. e6-4). These hinges are sometimes referred to as flex connections. Crowns are strut contact points where the struts contact one
another around the circumferential axis and are generally measured in number per 360-degree arc. Modules or segments are formed by
interconnected cells around the 360-degree arc of the stent with lateral borders deKned by crown, hinge, or fusion points. In some designs
(see Fig. e6-4), modules consist of individual units called rings that are joined (by welding or laser fusion) together to form a longitudinal
tubular stent (e.g., Assurant stent [Medtronic Inc., Minneapolis Minn.]). Closed-cell designs are those with all cells supported by contact with
another strut, whereas open-cell designs have portions of cells with unsupported struts not in contact with other struts (Fig. e6-5; also see Fig.
e6-4). By varying the strut/cell size, shape, conKguration, and frequency, manufacturers can alter many other properties of the stent
(flexibility, radiopacity, resistance to compression, hoop strength, etc.).
FIGURE E6-4 Terminology useful in describing and comparing stents (see text for discussion). Closed-cell Palmaz
Corinthian (top) stent has U-shaped flex hinges. Open-cell Bridge stent (bottom) is composed of individual modules or
rings fused together to form tubular stent. By varying number and/or location of spot-welds, stent flexibility and radial
strength can be altered.
FIGURE E6-5 Original Palmaz stent in its undeployed state is a slotted tube (bottom) that becomes diamond-shaped
cells on expansion (middle). Note that all struts were linear. From this design evolved the Palmaz Blue, made from
cobaltchromium alloy, with S-shaped hinge struts that increase flexibility and conformability (top). (Courtesy Cordis Corp.,
Warren, N.J.)
Stent FabricationThe proliferation of innovative stent geometry and cell architecture has improved longitudinal Gexibility, especially for BX stents. Early BX
designs were primarily rigid closed-cell “slotted-tube” conKgurations (e.g., Palmaz stent). These were produced by laser cutting linear
fenestrations in a 316 L-SS tube that became diamond shaped upon expansion (see Fig. e6-5). Laser cutting technology is signiKcantly more
sophisticated today, producing the variably shaped cells, struts, and hinges that can allow longitudinal bending while maintaining resistance
to compression in the transverse plane. Water-jet cutting has been used in a limited fashion to produce some coronary stents. Photochemical
etching is another technique to produce stents from tubes or sheets of metal.
9,10The evolution of nitinol SX stents has developed as the technology to fabricate the metal has progressed. The original nitinol stent
11described by Dotter was a simple spring coil shape. At that time, nitinol was only available in wire form, and the simplest way to shape it
was in a helical spiral. This basic concept was used until recently in the IntraCoil stent (LeMaitre Vascular, Burlington, Mass.) (Fig. e6-6).
Manufacturers then took nitinol wire and shaped it into cells, adding welds at contact points to hold the shape (e.g., Symphony [Boston
ScientiKc, Natick Mass.]) (see Fig. e6-6). When nitinol sheets were produced, manufacturers laser cut them, producing a fenestrated sheet.
These sheets were then rolled into tubes to form stents and welded at contact points. The original Angiomed Memotherm (C.R. Bard,
Covington, Ga.) was one of the Krst stents produced in this way (see Fig. e6-6). Once nitinol could be produced in tube form, manufacturers
began to laser cut the material to form most of the stents of the varying geometry in use today (see Fig. e6-6 and Table e6-2). More recently,
an SX stent design composed of woven nitinol wire was introduced (Supera Veritas (IDEV Technologies, Webster, Tex. [see Fig. e6-6]).
FIGURE E6-6 Evolution of self-expanding nitinol stents. Top to bottom, Coil-design of IntraCoil, hexagon-shaped cell of
wire-constructed Symphony Stent, laser-cut rolled/welded nitinol sheet construction of Memotherm, and laser-cut nitinol
tube design of E·Luminexx, most typical of current nitinol stent fabrication. (Top courtesy ev3/Covidien, Plymouth, Minn.;
middle courtesy Boston Scientific, Natick, Mass.; bottom courtesy C.R. Bard, Covington, Ga.)
Mechanical Properties
The mechanical properties of any stent will be related to both its design and composition and can impart both technical (e.g., deployment)
and biological (e.g., patency, infectability, etc.) characteristics. Properties that may affect both initial technical success and long-term patency
include metal surface area, resistance to compression, Gexibility, and fatigue resistance. Other practical considerations, important primarily
for placement, include amount of foreshortening, trackability, radiopacity, available sizes, and introducer size requirements.
Metal Surface Area
Metal surface area (MSA) refers to the amount of metal in contact with the vessel wall in the expanded state. This property is intimately
related to cell size and geometry and is often expressed as a percentage of the total area of the stent. As an example, a solid tube would have
an MSA ratio of 100% because it completely covers the vessel wall. Altering strut conKguration in laser-cut stents or decreasing the number of
wires or braiding angle in braided stents will alter MSA (see Fig. e6-3). Increasing strut number or width will increase MSA for any stent. Such
alterations generally alter hoop strength, radial force, and Gexibility. Although early animal research suggested that increased MSA increased
1 12neointimal proliferation, others have not found this to aLect thickness of the neointima. Practically speaking, MSA also has implicationsfor scaffolding, or the ability of a stent to support/exclude tissue from the vessel lumen. Small cell size and high MSA area generally provide
greater scaffolding.
Resistance to Compression
The ability of stents to maintain their shape under a stress load can be measured in many ways. The literature is inconsistent in both
terminology and methodology in this area. For the purposes of this chapter, the following deKnitions will be used. Radial strength, sometimes
13,14called radial force, describes a stent's ability to resist deformation under a compressive load (often done by compressing the stent
13,15,16between two parallel planar loads). Radial strength attempts to measure the external pressure a stent is able to withstand without
incurring clinically significant damage (>25% reduction of the stent's nominal diameter). This deformation is usually a buckling phenomenon
(i.e., deformation to a half-moon shape, rather than a uniform diameter constriction). This means that radial strength is highly dependent
upon lesion eccentricity and localized irregularities. Hoop strength, sometimes called radial resistive force, attempts to quantify a stent's ability
to resist circular compressive forces and is measured by the application of circumferential (beltlike) compressive force. Because of an absence
of quantitative data on the in vivo forces to which stents are subjected, the most appropriate criterion of stent “strength” is debated. In fact,
the types of forces that are applied to stents in vivo probably vary depending upon lesion characteristics. Nevertheless, these criteria allow
some comparison of a stent's relative ability to resist deformation.
Most BX stents initially resist deformation quite strongly (high hoop and radial strength). Eventually they will reach their yield point and
become irreversibly deformed. This pattern of deformation is called plastic deformation and is depicted by the stress/strain curve in Figure
e67, A. Conversely, SX stents do not become irreversibly deformed, but rather regain much of their diameter after being compressed (elastic
deformation) (Fig. e6-7, B). Their resistance to compression is minimal when a load is Krst applied, but then increases dramatically as the
load increases and the lumen narrows. This explains the often-observed clinical phenomenon of mild elastic recoil that can occur when SX
stents are used, but that is rare when BX stents are used.
FIGURE E6-7 A, Typical stress/strain curve for balloon-expandable stent. Initially, Palmaz stent resists compression, but
it reaches yield point, at which time plastic (irreversible) deformation occurs. B, Typical stress/strain curve for
selfexpandable stent. Wallstent behaves elastically throughout loading. When load is released, stent returns to preload
diameter. (Adapted from Dyet JF, Watts WG, Ettles DF, Nicholson AA. Mechanical properties of metallic stents: how do
these properties influence the choice of stent for specific lesions? Cardiovasc Intervent Radiol 2000;23:47–54.)
13,15-17Most studies evaluating compression resistance do not include many of the currently available stents. These studies, however, have
found that BX stents, which are rigid and undergo plastic deformation under load, have the highest radial and hoop strengths. Of tested
devices, the Palmaz medium (Cordis Endovascular/Johnson & Johnson, Warren, N.J.) and Bridge (Medtronic Inc. [no longer produced])
stents had the highest radial and hoop strengths.
The Wallstent has been used and studied widely. It is unique in that it is woven and wants to elongate when compressed. There are two
versions of the Wallstent marketed in the United States: the biliary endoprosthesis (“blue box,” less shortening) and iliac endoprosthesis
(“yellow box”). The Wallstent showed moderate resistance to compression that was 2.2-fold greater for the iliac (braid angle 140 degrees)
Wallstent compared with the less-shortening biliary version (braid angle 110 degrees). Both Lossef and Dyet showed greater radial strength
when the ends of the Wallstent were constrained, as would occur in vivo. Also interesting were the concepts that nesting both BX and SX16stents doubled their radial strength, and that placing a 10-mm Wallstent in an 8-mm tube increased its radial strength by 30%. Duda et
17al. studied SX stents using circumferential compression and found the S.M.A.R.T. stent (Cordis Endovascular/Johnson & Johnson) to have
the greatest resistance, followed by the Symphony (Boston ScientiKc), Memotherm (predecessor to the E·Luminexx [C.R. Bard]), and
Wallstent. This study likely underestimated the Wallstent's performance because the ends were not constrained. Unfortunately, the lack of
independent testing of the compression resistance of most new stents makes strength comparisons difficult.
SX stents also exert forces on the vessel in which they are placed. Chronic outward force is a term that has been coined to help quantify the
18force an SX stent exerts on the artery as it tries to expand to its nominal diameter, a property BX stents do not possess. It has been
suggested that this outward force may result in gain in luminal diameter in the days and Krst weeks after stent deployment, which may oLset
19 20some luminal losses from hyperplasia. This has been observed or reported infrequently, however.
Because of their superior resistance to compression, BX stents are generally favored for lesions requiring greater strength to resist recoil.
Examples would be heavily calciKed and highly eccentric lesions. For lesions requiring less support or where one expects motion or potential
compression (e.g., carotid arteries), SX stents are favored.
Flexibility
13Flexibility is deKned as the amount of force required to bend an expanded stent a given amount. This property is intricately linked to many
other important characteristics of a stent. Flexibility is related to trackability because it aLects an undeployed stent's ability to negotiate
tortuous anatomy. Once deployed, Gexibility is the primary determinant of conformability, or the stent's ability to conform to the artery's
course and caliber. This may also allow better wall apposition in tortuous vessels, which may improve endothelialization and overall patency
21rates. More Gexible stents can be deployed in tortuous vessels without signiKcantly altering the normal course of the artery (Fig. e6-8; also
see Fig. e6-10). Flexible stents will traverse tight bends through tortuous vessels, making deployment from contralateral location feasible.
Because more Gexible stents are more conformable, they are better suited to angulated vessels. Most BX stents are less Gexible than SX stents,
13,17although variations in cell structures and strut thickness and shape have reduced this difference.
FIGURE E6-8 Wallstent (left) is composed of Elgiloy filaments braided to form a tubular stent. LifeStent Self-Expanding
Stent (middle) is laser cut from a nitinol tube. Supera Veritas (right) is composed of interwoven nitinol wires. All are highly
flexible stents. Note how Wallstent and Supera Veritas can actually decrease cell size along inner radius of a curve without
buckling or kinking. (Left courtesy Boston Scientific, Natick, Mass.; middle courtesy C.R. Bard, Covington, Ga.; right
courtesy IDEV Technologies, Webster, Tex.)
Trackability
Trackability is a measure of the ability of a stent on its delivery system to follow a wire to a desired location. This property is critical in
allowing placement across a steep-angled aortic bifurcation or through tortuous anatomy without displacement of the stent from the delivery
17catheter. In general, the more Gexible a stent is, the more trackable it will be. Where trackability diLers from Gexibility is in its intimate
relation to the delivery catheter and mounting techniques. Until recently, the rule of thumb that SX stents were more trackable than BX stents
was valid. Newer BX stents have changed this to a certain extent, having become more trackable and Gexible than the original Palmaz
13,17stent. Recent changes have been made by most manufacturers to increase trackability of delivery systems.
Fatigue Resistance
Metal fatigue refers to the progressive structural damage that occurs when a material is subjected to cyclical loading at loads less than the yield
strength of the material. Fatigue resistance has not been studied extensively in the literature, but is especially important in sites subjected to
repetitive compression or bending, such as the superKcial femoral artery (SFA). Fractures (Fig. e6-9) of many diLerent stents have been
22-25reported, and fatigue resistance has received more attention as interventions in the SFA and popliteal artery increase.FIGURE E6-9 Fractures of nitinol stent in superficial femoral artery, with stenosis at fracture sites. Stent fractures in this
location are most likely related to metal fatigue secondary to complex forces this segment experiences. (Courtesy D. Allie,
M.D., and G. Biamino, M.D.)
Foreshortening
Foreshortening refers to the diLerence between the pre- and postdeployment length of the stent. Foreshortening varies according to stent
design, length, and the Knal diameter to which it is dilated. The amount/percent foreshortening for individual stents is included in Tables
e61, e6-2, and e6-3, as well as in the discussion of each stent. Figure e6-3 demonstrates the pre- and postdeployment lengths of three diLerent
stents. The amount of foreshortening must be considered when treating any lesion where the final endpoint is critical.
Radiopacity
Radiopacity refers to the visibility of a stent, generally under Guoroscopy, but is often tested using radiographic density. Fluoroscopic visibility
is critical for accurate placement of any stent, particularly in thick body parts such as the abdomen or pelvis. The inherent radiopacity of a
stent is intimately related to the metal from which it is composed. Platinum, 316 L-SS and CoCr alloys are highly radiopaque. Elgiloy is
moderately radiopaque. Nitinol is the least radiopaque of the metals used to make stents. To improve visibility and deployment accuracy,
manufacturers place markers (gold, tantalum, platinum) on the delivery catheter and/or the stent to delineate the expected Knal location of
the stent (though the eLects of such additions on biocompatibility are unknown). The radiopacity of a stent is also closely related to the
amount of metal in the stent, which is predicated on its size (i.e., diameter and length) and architecture. In general, larger-diameter/length
stents with more metal (i.e., wider/thicker struts, smaller cell size, higher MSA) are easier to see.
13,17,24 13 17Radiopacity, like other physical characteristics of stents, has been studied in a limited way. Dyet and Duda performed in vitro
studies of radiopacity using diLerent models. Dyet measured radiopacity compared to the thickness of a graded aluminum step wedge
17required to render a stent invisible. Using this model, only a 10% overall diLerence in radiopacity could be discerned. Duda et al. placed
stents in a plexiglass phantom and compared the measured average grayscale value of the stent within a prescribed region of interest. The
applicability of these models to clinical practice may be debated, since neither reproduces the human body. Furthermore, since the time of the
studies, most stents have been modiKed. Nonetheless, some points may be gleaned. Both authors found the Palmaz and Bridge stents to be
highly radiopaque. The Wallstent and S.M.A.R.T. were found to be intermediate in radiopacity. In a more contemporary study, Wiskirchen et
26al. studied radiopacity using a pelvic phantom model and variable spot-Klm and Guoro modes. Spot-Klm mode was found to be the most
reliable and detected nearly 100% of all tested devices. Changing to Guoro modes provided less consistent stent detection. Although BX stents
fared well (i.e., Palmaz Corinthian [Cordis Endovascular/Johnson & Johnson], AVE Bridge X [Medtronic Inc.]) at 15 pulses per second (PPS),
this study was especially surprising in that the SX Luminexx (C.R. Bard) did well in this mode, as well as at rates as low as 3 PPS. This study
points out that under diLering conditions, stents may have diLering radiopacities that may be apparent only in certain diMcult clinical
situations. An example would be during placement of short stents over dense bone (e.g., lumbar spine) where absolute accuracy is needed
(e.g., focal renal lesions). Radiopacity also becomes critical when treating obese patients or when the lesion is located over a dense bony
structure (e.g., common iliac stenosis at L5-S1). In these situations, one may have to use spot Klms during placement to conKrm location, as
even radiopaque stents can be difficult to visualize on fluoroscopy.
Balloon-Expandable StentsBX stents come in a wide variety of conKgurations today. All stents in this group will undergo permanent plastic deformation (i.e., crushing)
and therefore should not be placed in locations subject to Gexing (e.g., close to the inguinal ligament) or compression (e.g., neck). Unless
stated otherwise, they are constructed from laser-cut 316 L-SS tubes and are premounted on balloon catheters. Unmounted stents require
crimping on a on a scratch-resistant (to prevent balloon rupture during stent deployment) semi-/noncompliant balloon. Because these stents
are not contained within a delivery catheter, the introducer sheath must be long enough to cover the balloon and stent until the time of
deployment, at which point the sheath can be withdrawn, exposing the stent and balloon. The major diLerences between the many designs in
this category lie in architecture and delivery systems. Table 6-1 summarizes the important attributes and pertinent sizing criteria and of
individual stents, and Figure e6-10 illustrates various BX stent geometries.
FIGURE E6-10 Various balloon-expandable stent geometries. A, Express SD (Boston Scientific, Natick, Mass.). B, Valeo
(C.R. Bard, Tempe, Ariz.). C, IntraStent DS (ev3/Covidien, Plymouth, Minn.). D, Visi-Pro (note platinum markers)
(ev3/Covidien). E, Racer (Medtronic Inc., Minneapolis, Minn.). F, Assurant Cobalt (Medtronic Inc.). G, Omnilink (Abbott
Vascular, Santa Clara, Calif.). H, Herculink Elite (Abbott Vascular). I, Formula 418 renal (Cook Medical, Bloomington, Ind.).
(Photos courtesy respective manufacturers.)
Palmaz (Cordis Endovascular/Johnson & Johnson)
The prototypical closed-cell BX Palmaz stent was the Krst stent laser cut from a tube of 316 L-SS. Upon expansion, the staggered rows of
linear slots become diamond-shaped cells (see Figs. e6-3 and e6-5), and the stent foreshortens slightly. Various sizes are available (see Table
6-1), with foreshortening varying by stent length and the diameter to which it is inGated. Foreshortening is approximately 10% (3.8 mm) and
23% (7 mm), respectively, when large and medium stents are expanded to maximal diameters. The large size stent is FDA approved for iliac
use, and the medium-sized stent is approved for both iliac and renal use. An extra-large (XL 14-25 mm diameter) version is also available for
large-vessel applications.
16 13,17The original Palmaz stent set the standard for radiopacity and radial strength, but it lacked Gexibility and trackability. For these
reasons, it is best placed from an ipsilateral approach in a relatively straight vessel requiring a great deal of radial strength. An example of
an ideal lesion would be an ostial common iliac artery stenosis or aortic stenosis.
Palmaz Genesis (Cordis Endovascular/Johnson & Johnson)
The Genesis remains a closed-cell design but diLers from the original Palmaz stent in strut and hinge architecture. It employs S-shaped hinges
(see Fig. e6-5) that increase stent Gexibility and trackability while decreasing foreshortening and improving scaLolding. The ends of the stent
are rounded to decrease trauma to the artery and delivery balloon. Compression resistance, according to manufacturer testing (MT) is equal
to the original Palmaz stent. Radiopacity is slightly less than the standard Palmaz stent. Foreshortening varies by stent length/inGation but is
minimal (range 0-3 mm, 0%-14%). Premounted stents incorporate a proprietary nesting design whereby the stent is embedded in the balloon
interstices. The manufacturer reports that stent retention is three times greater than conventional mounting. The increased Gexibility
improves placement from a contralateral approach and allows placement in longer, more tortuous vessels. It has been used safely to treat
27renal artery stenosis."
Palmaz Blue (Cordis Endovascular/Johnson & Johnson)
The stent is constructed from L605, a CoCr alloy enhanced with tungsten, which is less ferromagnetic than stainless steel. It remains a
closedcell design with S-shaped Gex hinges (see Fig. e6-5) similar to the Genesis. Corporate studies suggest that this alloy/design possesses greater
hoop strength with a lower MSA ratio compared to 316 L-SS. It is designed to provide increased resistance to compression and radiopacity,
with a lower profile and superior flexibility and deliverability compared to earlier versions of the Palmaz.
Express (Boston Scientific)
The Express design consists of alternating rows of large (macro) and small (micro) sinusoidal rings with Kve longitudinal hinges connecting
the crowns (Fig. e6-10, A). Rather than connecting the apices of the crowns, the connections are made from the inner margin of one to the
apex of the next, sometimes referred to as a peak-to-valley con guration (see Fig. e6-10, A). The relatively open-cell design provides Gexibility
and conformability. ScaLolding is expected to be slightly less than closed-cell designs with smaller cell size. Radial strength is reported (MT)
to be on par with the Genesis. The Express is available in large diameter (LD) (0.035-inch guidewire) or small diameter (SD) (0.018-inch
guidewire) sizes.
Formula 414RX/Formula 418 (Cook Medical, Bloomington, Ind.)
The Formula 414RX (0.014 monorail)/Formula 418 (0.018 OTW) is a relatively small-sized open-cell stent (Fig. e6-10, I) that has virtually no
foreshortening upon deployment (MT). It is mounted on a special balloon with minimal balloon beyond the stent end. It has radial force on
par with the Genesis (MT). Its low profile is designed to assist in crossing lesions.
IntraStent (ev3/Covidien, Plymouth, Minn.)
The IntraStent (IS) series includes stents of various sizes with similar open-cell architecture but diLering in their wall thickness and cell
size/number. Several devices are manufactured, including DoubleStrut LD (DSLD), Mega LD (large diameter), and Max LD. All IntraStents are
unmounted and have rounded edges. The DSLD has parallel struts (Fig. e6-10, C) that increase overall MSA, radiopacity, and radial strength
of the stent, reported to be on par with the medium Palmaz stent (MT). The Mega LD and Max LD add progressive radial force at a cost of
some decrease in Gexibility and larger delivery sheath requirement. All IntraStents feature zero foreshortening at recommended inGation
diameters.
ParaMount Mini GPS and Visi-Pro GPS (ev3/Covidien)
These open-cell stents feature tantalum markers at the ends to increase radiopacity (Fig. e6-10, D). They exhibit minimal/no foreshortening at
recommended lengths. They are both highly Gexible (on Par with Palmaz Genesis [Cordis Endovascular/Johnson & Johnson]) with relatively
small cell size to improve scaLolding and conformability (MT). The radial strength of the Visi-Pro GPS is reported (MT) to be near that of the
Express LD (Boston Scientific). In addition, it is the only available BX stent that has radiopaque markers on the ends to assist in placement.
Assurant Cobalt (Medtronic Inc.)
The Assurant Cobalt represents the latest in the Bridge stent series. The Bridge design is unique in that it is based on laser-cut rings (see Fig.
e6-4) that are fused at contact points. The Assurant Cobalt is the Krst Bridge stent made of CoCr (Fig. e6-10, F). By altering the number and
location of the fusion points, both open- and closed-cell stents can be produced, and the radial strength, Gexibility, and conformability may be
varied. Previous design variations have been marketed as the Bridge Assurant, Bridge Flexible Iliac, Bridge Flexible Biliary, and Bridge Extra
Support (XS). The Assurant Cobalt is currently available. Radiopacity for the 316-SS version of this stent was similar to the Palmaz large
13,17stent, with radial strength equal to or greater than the Palmaz medium stent. The manufacturer reports that radiopacity is even greater
for the Assurant Cobalt. The Assurant Cobalt has very favorable Gexibility and conformability that results from short strut length and
staggered fusion points around the stent (MT). This results in smaller cells and improved scaLolding while maintaining minimal
foreshortening. A proprietary mounting system assists in securing the stent to the balloon with less chance for stent slippage during
deployment.
Medtronic Racer (Medtronic Inc.)
The Racer (Fig. e6-10, E) is similar in modular ring design to the Bridge/Assurant Cobalt stents. CoCr alloy composition increases radial
strength, Gexibility, and radiopacity compared with 316 L-SS, despite having a 50% thinner wall (MT). Foreshortening is approximately 3.9%
(MT) when fully expanded, which compares favorably with the foreshortening of similar stents (11.7% for Genesis). Small cell size assists in
tissue scaLolding. A proprietary mounting system assists in securing the stent to the balloon with less chance for stent slippage during
deployment.
Omnilink (0.018-inch and 0.035-inch) (Abbott Vascular, Santa Clara, Calif.)
The premounted Omnilink design consists of open cells that are connected peak to valley by interrupted longitudinal struts (Fig. e6-10, G).
This geometry results in a stent that is quite Gexible, trackable, and conformable and can usually be placed across the aortic bifurcation. The
small cell size may be useful in situations where tissue prolapse is concern (i.e., improved scaLolding). Radiopacity, being less than the
Palmaz stent, is moderate. Radial strength (MT) is similar to Palmaz Genesis. The smaller-diameter (4-7 mm) premounted stents can be
overdilated to a maximum of 8 mm, and the larger-diameter design can be overdilated to 11 mm. The Omnilink Elite, currently only available
in Europe, is a cobalt-chromium version of the stent. Like other CoCr stent variations, it has a lower proKle and improved radial strength
compared with the previous 316-SS version.
Guidant RX Herculink Elite (Abbott Vascular)
Architecture is similar to other stents based upon multilink design, consisting of open cells connected peak to valley by interrupted
longitudinal struts (Fig. e6-10, H). This geometry results in a stent that is quite Gexible, trackable, and conformable. The small cell size may
be useful in situations where tissue prolapse is a concern (i.e., improved scaLolding). Cobalt-chromium construction is said to improve
28radiopacity and radial strength compared to its predecessor, the Herculink Plus. The Herculink Elite has nine crowns per module, whichimparts greater radial support, albeit with some loss of Gexibility. The stent consists of eight (18-mm stent) or six (13-mm stent) modules each
connected by three longitudinal stent struts (see Fig. e6-10, H). This results in favorable scaLolding and relatively small cell size. Proprietary
“Grip” technology improves stent Kxation on the balloon. As with most BX stents, foreshortening depends on size/Knal diameter (range
12%14%). The device is mounted on a monorail (RX) system. It has been used in renal applications.
Valeo (C.R. Bard)
The Valeo is a relatively open-cell design, moderately Gexible BX stent that is laser cut from a 316 L-SS tube (Fig. e6-10, B). Radiopacity
should be in line with other stents made of 316-SS, although little data are available because it is relatively new to the market.
Self-Expanding Stents
SX stents come in a wide variety of conKgurations today. Stents in this group will not undergo permanent plastic deformation (i.e., crushing)
and therefore can be placed in locations subject to Gexing (e.g., close to inguinal ligament) or compression (e.g., neck). Unless stated
otherwise, they are constructed from laser-cut nitinol tubes and are premounted inside a delivery catheter, thereby allowing them to be
advanced beyond the introducer sheath without damaging/dislodging the stent. Following deployment, an angioplasty balloon is usually
required to fully expand the stent. Occasionally, when used to treat a Gow-limiting dissection following PTA, further balloon expansion is not
required. All stents are highly Gexible and conformable. Most stents in this category, with the exception of the Supera Veritas (IDEV
Technologies), require oversizing of 1 to 2 mm to ensure secure Kxation. The hoop strength is generally low to moderate, and foreshortening
is minimal (Table 6-2 summarizes pertinent attributes and sizing criteria of individual stents, and Figure e6-11 illustrates various SX stent
geometries.FIGURE E6-11 Various self-expanding stent geometries. A, S.M.A.R.T. Control (Cordis Corp., Bridgewater, N.J.). B,
E·Luminexx (C.R. Bard, Tempe, Ariz.). C, Xact (Abbott Vascular, Santa Clara, Calif.). D, Neuroform (Boston Scientific,
Natick, Mass.). E, Protege GPS (ev3/Covidien, Plymouth, Minn.). F, Sentinol (Boston Scientific). G, Absolute Pro (Abbott
Vascular). H, Acculink (Abbott Vascular). I, Zilver (Cook Medical, Bloomington, Ind.). J, Complete SE Stent System
(Medtronic Inc., Minneapolis, Minn.). K, EverFlex (ev3/Covidien). (Photos courtesy respective manufacturers.)
Wallstent (Boston Scientific)
Although recent trends have favored nitinol for the creation of SX stents, the Wallstent represents the original self-expanding stent design and
oLers a proven track record throughout the body. Braided Elgiloy Klaments result in a small-sized closed-cell geometry (see Figs. e6-3 and
e68) that has generally been the standard for Gexibility and trackability to which all other stents are compared. The ends of the stent are Gared
13,17to assist in anchoring. Radiopacity is only slightly less than the Palmaz stent. Radiopaque markers are present on the delivery system to
assist in placement. Metal surface area varies by diameter and the particular Wallstent selected, but is generally 20% or greater, providing
solid scaLolding. Foreshortening is substantial and varies between 20% and 50% according to length and Knal diameter of the stent. One
unique feature of the Wallstent is its reconstrainable introducer system that allows the stent to be reconstrained for a variable percentage of
its total length (up to 88%) and repositioned or removed. Resistance to compression, as previously discussed, is low to moderate. The
Wallstent is available in several varieties including iliac, venous, biliary, tracheobronchial, and carotid. The carotid Wallstent is designed to
be used in conjunction with the FilterWire EZ (Boston ScientiKc). Sizing varies among the diLerent devices, as do some of the physical
characteristics such as foreshortening, braid angle, and hoop strength. Knowledge of constrained and unconstrained lengths is critical to
ensure appropriate stent placement. Caution should used when placing the stent near vessel branch points because of relative diMculty in
predicting exactly the final position of the stent.
Supera Veritas (IDEV Technologies)
The Supera Veritas is unique among SX stents in that it is constructed from six pairs of closed-end interwoven nitinol wires (see Fig. e6-8).
This results in a highly Gexible closed-cell geometry stent. In terms of being a “woven” design, it resembles the Wallstent more than othertypical nitinol stents that are cut from tubes. MT suggests that this design results in radial strength that is signiKcantly higher (3-4×) than
that of standard SX nitinol stents. MT also suggests fatigue/fracture resistance signiKcantly higher (10×) than standard nitinol stent designs.
Unlike the Wallstent, this design exhibits zero foreshortening, but it cannot be recaptured. Radiopaque markers are present on the delivery
catheter to assist in placement.
Symphony (Boston Scientific)
The Symphony is unique in that it is constructed from a single strand of nitinol wire arranged in a hexagonal pattern and welded at the
contact points (see Figs. e6-3 and e6-6). It has larger cells than most in this category and is less Gexible but tracks well. To improve
visualization, platinum sleeve markers have been welded to the ends of the stent, and marker bands are present on the delivery catheter. The
radial strength is slightly less than the Wallstent. Foreshortening is 2% to 11%. The stent is mounted within a pistol-grip delivery system and
is deployed by depressing the trigger.
S.M.A.R.T. Control (Cordis Endovascular/Johnson & Johnson)
S.M.A.R.T. is an acronym for Shape Memory Alloy Recoverable Technology. The S.M.A.R.T. was initially introduced in 1998 and was one of
the Krst open-cell geometry stents (Fig. e6-11, A). This architecture resulted in favorable Gexibility, shapeability, and wall apposition. This
segmented design is engineered to allow rings to function semi-independently and improve vessel conformability, with small cell size
17assisting in scaLolding. Radiopacity of the original S.M.A.R.T. was reported to be similar to the Wallstent. Marker bands on the delivery
17catheter and stent assisted in placement accuracy. Hoop strength, according to the manufacturer and independent study, was similar to or
slightly greater than the Wallstent. The addition of coined tantalum markers at the ends helped make the stent more visible during
deployment. The S.M.A.R.T. Control was added in 2002, with an altered deployment system featuring a rotating thumb screw designed to
improve deployment accuracy.
Precise, Precise RX, Precise Pro RX (Cordis Endovascular/Johnson & Johnson)
Precise is a modiKed version of the S.M.A.R.T. stent, available as the OTW 0.018-inch-guidewire–compatible Precise and the monorail
0.014inch-guidewire–compatible Precise RX/Precise Pro RX. The current FDA-approved carotid designs include the Precise Carotid and Precise Pro
RX. Both are approved for use with the Angioguard embolic protection system (EPS) (Cordis Endovascular/Johnson & Johnson). The Precise
delivery system and stent are extremely Gexible because the stent has the same segmented open-cell design as the S.M.A.R.T. Radiopaque
markers are not present on the stent, but markers are present on the delivery catheter to assist in accurate placement. This segmented
29 30autotapering design may oLer some beneKt in highly tortuous lesions. It was used safely in the SAPPHIRE carotid trial and SAPPHIRE
31registry with the Angioguard system.
E·Luminexx (C.R. Bard)
The E·Luminexx has replaced the Luminexx stent. Both stents evolved from the Memotherm Flexx (C.R. Bard). The E·Luminexx features several
enhancements to the Luminexx. Its small size and open-cell geometry continue to yield a Gexible and conformable stent with solid scaLolding
(Fig. e6-11, B). Enhancements to the E·Luminexx include adjustments in the cell size throughout the range of stent sizes, which are reported
(MT) to provide more equivalent radial force throughout the range of sizes. An improved electropolishing process is reported to decrease
corrosion (MT). The ends of the struts remain rounded to decrease trauma to the vessel wall, with a 2-mm Gare to improve anchoring.
26Radiopacity remains very good owing to the four large tantalum markers (see Fig. e6-6) welded to each end of the stent, as well as marker
bands on the delivery catheter. A proprietary StentLoc mechanism allows compression along the entire length of the stent to reduce
“stentjumping” during deployment. The delivery system oLers a removable one-handed ratchet-type release designed to maximize placement
accuracy, with an option for two-handed retraction of the covering catheter while holding the delivery system in place.
Enterprise (Codman Neurovascular, Raynham, Mass.)
The Enterprise, like the Neuroform (see later discussion), was designed for delivery and use in the intracranial circulation. This device is FDA
labeled for use with embolic coils for the treatment of wide-neck intracranial aneurysms not amenable to surgical clipping. The stent features
a closed-cell design and Gared stent ends, both of which improve wall apposition. The closed-cell design also reduces the chance of the stent
prolapsing into the aneurysm. Radiopaque markers (four) on the ends of the stent improve visibility. The delivery wire is designed with
variable Gexibility to improve pushability. The wire also has a more radiopaque segment that corresponds to stent location to assist in
accurate placement. The delivery system allows for one-time stent recapture. It is delivered through a previously placed microcatheter.
Wingspan (Boston Scientific)
The Wingspan was designed for delivery and use in the intracranial circulation to treat intracranial atherosclerotic disease (ICAD). It has an
open-cell geometry with thin walls (0.0030 inches) to make it maximally Gexible. This device carries a Humanitarian Device Exemption
(HDE) and is FDA labeled for use in the treatment of ICAD with over 50% stenosis that is refractory to medical management. Foreshortening
is minimal (2.4%-7.4%). Radiopaque markers (four) on the ends of the stent improve visibility.
Sentinol (Boston Scientific)
The Sentinol features open, variable-sized cell architecture (small, medium, and large cells) designed to increase Gexibility and wall
apposition while maintaining radial force and providing improved scaLolding compared with larger open-cell designs (Fig. e6-11, F). The
stent has platinum markers at the ends to increase radiopacity. The company reports a proprietary process designed to neutralize the stent
surface by removing nickel ions, making it titanium rich, which may increase corrosion resistance and improve biocompatibility.
Neuroform3, Neuroform EZ (Boston Scientific)
The Neuroform3 represents the latest iteration of the Neuroform stent design. The Neuroform was designed for delivery and use in the
intracranial circulation. It has variable-sized open-cell geometry (2 hinges per 360 degrees at ends and 3 hinges per 360 degrees in midstent)
with thin walls to make it maximally Gexible (Fig. e6-11, D). This device carries an HDE and is FDA labeled for use with embolic coils for thetreatment of wide-neck intracranial aneurysms not amenable to surgical clipping. Neuroform was originally approved in 2002. The
Neuroform3 has undergone modiKcations to improve deliverability, reduce stent slippage on the delivery system, improve deployment
accuracy, and improve wall apposition. The current design is reported to provide greater scaLolding for coil mass support and suMcient
radial force to generate stability within the vessel (MT). Foreshortening is minimal (1.8%-5.4%). The Neuroform EZ is produced by Boston
ScientiKc and marketed by Stryker Neurovascular (Kalamazoo, Mich.). It features a delivery system more akin to the Enterprise (Codman
Neurovascular) that is simply placed through a microcatheter of the operator's choice.
Xact (for use with Emboshield Filter) (Abbott Vascular)
The Xact is FDA approved for carotid use with the Emboshield Nav6 (Abbott Vascular) EPS. It features closed-cell architecture (Fig. e6-11, C)
that may oLer some protection from tissue prolapse/plaque embolization in certain cases. The midstent has higher MSA and hoop strength to
increase scaffolding in the region of the lesion. Similar to the Acculink (Abbott Vascular), it is available in both straight and tapered designs.
Xpert (Abbott Vascular)
The Xpert features highly open-cell architecture compatible with a 4F sheath (except 6 mm × 60 mm and 8 mm sizes). The stent has been
engineered for small-diameter vessel applications, with strut thickness as low as 0.09 mm. Despite this, the manufacturer reports radial
strength comparable to similar devices (MT). Chronic outward force is low. The small size of the delivery system makes it useful when larger
systems might not be tolerated.
Zilver 518, Zilver 518RX, Zilver 635 (Cook Medical)
The Zilver stent series feature open-cell architecture with hinges oriented along the longitudinal axis of the stent (Fig. e6-11, I) in a
peak-tovalley conKguration. There is no appreciable foreshortening on deployment. To improve visibility, the ends of the stent have been coined
with four gold markers. The Zilver 518 is an OTW 0.018-inch-compatible device, the Zilver 518 RX an 0.018-inch monorail version, and the
Zilver 635 an OTW 0.035-inch-compatible version. The Zilver PTX, currently undergoing international study, is a paclitaxel-eluting version of
32,33the stent currently only available on trial in the United States.
LifeStent, LifeStent Vascular, and LifeStent Solo (C.R. Bard)
The LifeStent family of stents, another small open-cell design, feature hinge points arranged in a helical fashion around and along the length
of the stent (see Fig. e6-8). This design is reported to be more Gexible than circumferential hoop designs because it allows torsion in addition
to longitudinal bending (MT). The design favors Gexibility, conformability, kink resistance, and supportive tissue scaLolding. Radiopaque
markers on each end enhance radiopacity. The hydrophilically coated delivery system has a rotating wheel (on LifeStent Vascular and
LifeStent XL) or a trigger mechanism (on LifeStent Solo) that retracts the outer catheter during stent placement. LifeStent Vascular and
LifeStent Solo carry an FDA indication for the SFA and proximal popliteal artery.
Protege GPS, Protege EverFlex, Protege BIGGS, Protege RX (ev3/Covidien)
The Protege stent series features open-cell architecture with periodic strut linkages aligned longitudinally and circumferentially, resulting in a
segmented design reminiscent of ev3's BX IntraStent. Coined tantalum markers at the ends of both stents increase radiopacity. The helical
alignment of strut linkages in the EverFlex (Fig e6-11, K) is reported to increase Gexibility (MT) compared with the Protege GPS (Fig. e6-11,
E). The Protege GPS BIGGS is available in larger diameters (9-14 mm). The company reports 0% foreshortening on deployment for all
designs. The proximal ends of the stents are anchored in a notched ring to prevent stent “jumping” on deployment. The delivery catheter has
a side port that allows contrast injection to confirm stent position prior to deployment.
Protege RX (ev3/Covidien)
The Protege RX is a monorail version of the Protege speciKcally designed for carotid application. It is designed for use with the SpiderFX EPS.
It has many similarities to the Protege series, including tantalum markers to increase radiopacity and a notched ring at the proximal end to
prevent stent “jumping” during deployment. The tapered version is designed to have a more anatomically designed taper for better Kt in the
carotid bulb. A radiopaque marker on the delivery catheter marks the location of the taper transition.
RX Acculink (Abbott Vascular)
The RX Acculink is FDA approved for use in the carotid artery in conjunction with the Accunet EPS (Abbott Vascular). It features a Gexible
and conformable design with a relatively open but small cell size to minimize tissue prolapse and provide solid scaLolding (eFig 6-11, H).
Longitudinally aligned struts minimize foreshortening. The monorail deployment system features a Kxed deployment handle that allows
single-handed deployment. It is primarily intended for carotid application and is available in both straight and tapered versions. It carries an
FDA indication for use in both standard- and high-risk surgical patients.
Absolute Pro (Abbott Vascular)
The Absolute Pro evolved from the Dynalink stent and as such shares its “nested ring” geometry. This results in a highly Gexible and
conformable stent (Fig. e6-11, G). Platinum markers have been added to the ends of the stent to improve radiopacity. The two-handed
delivery system also diLers from the Dynalink and others in that it is “triaxial” (outer stabilizing catheter, middle covering sheath, and a
braided inner sheath) and allows limited injection through the delivery catheter to aid in deployment accuracy.
Complete SE (Medtronic Inc.)
The Complete SE stent system has replaced the Aurora stent system (Medtronic Inc.). The Complete SE has an open-cell, 12-crown,
4connection, U-joint architecture similar to Aurora (Fig. e6-11, J). New to the Complete SE stent is the introduction of variable strut lengths
into the circumferential strut pattern that causes the stent crowns to oLset when fully expanded. This provides room for the crowns to
“interleave” when the stent is bent or axially compressed and increases the Complete SE's kink resistance and Gexibility. Four tantalum
markers were added to each end of the Complete SE stent to increase radiopacity. Additional improvements were made to the Complete SE
stent delivery system compared to Aurora. A three-layer design was employed using a stability member to minimize valve friction and aid indeployment accuracy, and the entire stent size matrix is now 6F-sheath compatible. The handle design allows the operator to deploy the
stents using a mechanical advantage mechanism and/or a traditional slider mechanism.
Peripheral Stent-Grafts
Stent-grafts represent a melding of stent and surgical bypass conduit technology (Fig. e6-12). The conduit material, generally a synthetic
textile such as Dacron, extruded polytetraGuoroethylene (ePTFE), or polyethylene terephthalate (PET), is used as a membrane to cover
and/or line the stent. Large-diameter stent-grafts have gained acceptance in the treatment of thoracic and abdominal aortic aneurysms for
selected patients. Peripheral stent-graft devices have a variety of uses, including treatment of traumatic injuries (vascular, biliary, etc.),
exclusion of aneurysms (e.g., internal iliac artery aneurysm), malignant strictures/tumor obstruction (e.g., biliary), and potentially in
treating patients with occlusive disease. By combining the support of a stent and the barrier eLect of the membrane, it was hypothesized that
34stent-grafts might limit restenosis and improve patency. Their use in controlling bleeding and excluding aneurysms has been established,
35but their exact role in occlusive disease remains to be fully defined.
FIGURE E6-12 Various stent-graft devices. A, Wallgraft (Boston Scientific, Natick, Mass.) B, Viabahn and Viatorr (W.L.
Gore & Associates, Flagstaff, Ariz.). C, iCast (Atrium Medical, a Maquet Getinge Company, Hudson, N.H.). D, Flair (C.R.
Bard, Tempe, Ariz.). (Photos courtesy respective manufacturers.)
Wallgraft (Boston Scientific)
The Wallgraft consists of an inner (endoskeleton) Wallstent covered with PET graft material that is bonded to it with an adhesive (Fig.
e612, A). The device is similar to the Wallstent in terms of Gexibility and also undergoes signiKcant foreshortening on deployment. The
Wallgraft diLers in that its ends not Gared and thus the manufacturer emphasizes oversizing by 1 to 2 mm. Like the Wallstent it has
radiopaque markers on the delivery catheter and can be reconstrained and repositioned during placement. To improve radiopacity a
platinum wire has been added. Fully enclosed in its delivery catheter, it can be advanced without a covering sheath. The device has been used
36to treat ruptures after percutaneous transluminal angioplasty (PTA), traumatic and atherosclerotic aneurysms, occlusive disease,
37emboligenic plaque, and dialysis graft pseudoaneurysms. Theoretically, woven PET is more prone to infection than ePTFE, but clinically,
infection has not been problematic.
Viabahn (W.L. Gore & Associates, Flagstaff, Ariz.)
The Viabahn consists of a radially reinforced ultra-thin ePTFE tube with an externally supported structure of wound nitinol wire (Fig. e6-12,
B). The company has added a proprietary heparin-bonded surface to the ePTFE lining and contouring of the proximal end to the most recent
design modiKcation. It is mounted on a delivery catheter and is extremely Gexible, but may become lodged/displaced in the delivery sheath in
extremely tortuous anatomy. Because it has no constraining cover, it must be fully covered with a delivery sheath until the time of
deployment. It is deployed by pulling on a single retaining suture. When compressed, it is low to moderate in radiopacity; however, the
delivery catheter has two radiopaque metallic bands that mark the ends of the compressed device. The device is self-expanding and requires
both predilation to allow passage of the device and post-deployment dilation to insure optimal results. It undergoes minimal foreshortening
on deployment. Slight oversizing is recommended by the manufacturer, but too much oversizing may lead to graft “wrinkling” that may
require correction with PTA or stent placement. Like the Wallgraft, there have been multiple case reports of using the Viabahn safely to treat
38PTA ruptures, arterial trauma, aneurysms, pseudoaneurysms, and Kstulas. There are more data for use of the Viabahn in treating occlusive
39,40-42disease.
Viatorr (W.L. Gore & Associates)
The Viatorr is specially designed and FDA approved for transjugular intrahepatic portosystemic shunt (TIPS). Its design is similar to the
Viabahn, but the graft material has two layers. The inner blood-contacting layer is a seamless ePTFE tube. The outer reinforcing layer is a
helically wrapped Klm of less permeable ePTFE that is resistant to transmural bile permeation. The device has a lined hepatic segment and an
unlined chain-link portal region (see Fig. e6-12, B). The interface between the two regions is marked by a circumferential marker band, and
the trailing end of the device is marked by a gold marker. The primary application is in TIPS, where it has shown favorable patency
43compared with standard uncovered stents. The device is similar to the Viabahn and must be completely covered by the introducer sheath
prior to deployment. It has minimal foreshortening.
Viabil (W.L. Gore & Associates)
The Viabil is similar to Viatorr but is speciKcally designed for biliary application using nonporous ePTFE and higher-strength supportingnitinol wire to increase hoop strength. It is available both with and without a 2-cm proximal segment with holes that allow drainage of
covered side ducts if needed.
Fluency Plus (C.R. Bard)
The Fluency Plus consists of a self-expanding (Luminexx) nitinol skeleton encapsulated within two ultrathin layers of ePTFE. Four radiopaque
tantalum markers are present on each end of the stent graft to assist in placement. These markers and approximately 2 mm of the stent at the
ends of the graft are not covered with ePTFE. An additional radiopaque marker band is integrated into the outer sheath and moves toward
the handle during deployment, further assisting placement control. The Fluency Plus adds a proprietary delivery system designed to improve
trackability. Carbon impregnation on the inner fabric is designed to decrease platelet aggregation (MT).
Flair (C.R. Bard)
The Flair (Fig. e6-12, D) is similar in many ways to the Fluency Plus. Similar to the Fluency Plus, it consists of a self-expanding (Luminexx)
nitinol skeleton encapsulated within two ultrathin layers of ePTFE, with the addition of a Gared end (straight version also available). The
Gared end is designed to improve outGow in arteriovenous grafts, especially where there is a caliber discrepancy between the graft and the
44native vein. When placed across an arteriovenous graft venous anastomosis, the Gared end has been shown to reduce turbulence and
promote laminar Gow compared to a straight graft (MT). The tantalum markers available on the Fluency Plus are not present on the Flair.
The entire graft is covered with ePTFE, another important distinction compared with the Fluency Plus, which has bare metal ends. A
radiopaque marker band integrated into the outer sheath moves toward the handle during deployment, assisting placement control. Carbon
impregnation on the inner fabric is designed to decrease platelet aggregation.
iCast (Atrium Medical, Hudson, N.H.)
The iCast device (marketed outside the United States as Advanta V12 and FDA approved for tracheobronchial use) is a premounted 316 L-SS
BX encapsulated in microporous PTFE using a proprietary lamination process (Fig. e6-12, C). Like most BX devices, it should be covered by
the delivery sheath until deployment and should not be placed at sites of compression. The device may be dilated from 5 to 9 mm (small) or
10 to 12 mm (large). Foreshortening varies by diameter of inflation and ranges from 2.1% at 5 mm to 11.6% at 9 mm.
Drug-Eluting Stents and Restenosis
In response to physiologic stimuli (i.e., wound healing), normally quiescent smooth muscle cells (SMC) within the vessel wall can be activated
to migrate and proliferate. Beyond this normal physiologic response, pathologic SMC migration and proliferation can be seen after balloon
angioplasty (PTA) and stent placement, resulting in intimal hyperplasia. Restenosis, related in large part to intimal hyperplasia, represents
the major limitation to the durability of stent placement today.
Restenosis rates vary by stent and location. The exact numbers are beyond the scope of this review, but some generalities may be drawn.
Based upon the collected data to date, primary 1- to 2-year patency rates are as follows: Carotid patency rates are approximately 90% to
42,45,4695%, iliac arteries approximately 80% to 95%, renal arteries 75% to 90%, and SFAs 22% to 65%. The discrepancy between technical
success rates and long-term patency has led to a search for diLerent methods to decrease stenosis following stent placement. Multiple agents
have been evaluated as having potential use in reducing restenosis. These have included immunosuppressive, antiproliferative,
antiinGammatory, antithrombotic, modulators of extracellular matrix, and pro-healing agents. One of the most promising areas is in
drug7,8coated stent technology. Although drug-eluting stents have already had a huge impact on coronary stenting, questions remain as to their
47,48overall long-term safety and eMcacy. It remains to be seen whether drug delivery will be important for peripheral artery stenting,
where restenosis rates are lower. The most promising agents to date include sirolimus and paclitaxel. Early data suggested a role for
drug49eluting stents in the SFA, but the 2-year follow-up study failed to show a signiKcant beneKt for a sirolimus-eluting stent compared with a
23 32,33bare stent. One-year data using a paclitaxel-eluting stent in the SFA appears promising, but longer-term follow-up will be required.
There is much ongoing research in this area.
Summary
Stents have revolutionized endovascular management of peripheral arterial disease. They have been responsible for the transition in
revascularization from surgery to interventional means for many vascular territories, including coronary, subclavian, aortoiliac, carotid,
renal, and visceral arteries. They may eventually be the preferred therapy for femoropopliteal obstruction. The impact of stents on clinical
practice has been enormous. By understanding the basic biological, mechanical, and design properties of these devices, the practitioner is
better able to select the appropriate device for individual applications.
Key Points
50• Vascular stents, conceptualized by Dotter and Judkins in 1964 (“endovascular splint”) have revolutionized percutaneous
management of vascular disease.
• The Palmaz stent (Cordis Endovascular/Johnson & Johnson, Warren, N.J.) received U.S. Food and Drug Administration approval
for iliac use in 1991, and the Wallstent (Boston Scientific, Natick, Mass.) was approved in 1996.
• Since 1996, devices have proliferated so rapidly, little peer-reviewed data are available on any single device, making
comparisons relatively difficult.
• Practical considerations—stent size, sheath requirement, flexibility, radiopacity, and the like—are often the best way to choose a
stent, given lack of outcomes data.
• Stent-grafts allow treatment of active bleeding, aneurysms, and pseudoaneurysms and may someday show benefits over stents for
occlusive disease.
• Drug-eluting stents have proven benefit in certain coronary lesions, but remain unproven in the peripheral arterial circulation.▸ Selected Readings
Duda, SH, Poerner, TC, Wiesinger, B, et al. Drug-eluting stents: potential applications for peripheral arterial occlusive disease. J Vasc Interv
Radiol. 2003; 14:291–301.
Duerig, TW, Wholey, M. A comparison of balloon- and self-expanding stents. Minim Invasive Ther Allied Technol. 2002; 11:173–178.
Dyet, JF, Watts, WG, Ettles, DF, Nicholson, AA. Mechanical properties of metallic stents: how do these properties influence the choice of stent
for specific lesions? Cardiovasc Intervent Radiol. 2000; 23:47–54.
Leung, DA, Spinosa, DJ, Hagspiel, KD, et al. Selection of stents for treating iliac arterial occlusive disease. J Vasc Interv Radiol. 2003; 14:137–
152.
Lossef, SV, Lutz, RJ, Mundorf, J, Barth, KH. Comparison of mechanical deformation properties of metallic stents with use of stress-strain
analysis. J Vasc Interv Radiol. 1994; 5:341–349.
Morice, MC, Serruys, PW, Sousa, JE, et al. A randomized comparison of a sirolimus-eluting stent with a standard stent for coronary
revascularization. N Engl J Med. 2002; 346:1773–1780.
Palmaz, JC. Intravascular stents: tissue-stent interactions and design considerations. AJR Am J Roentgenol. 1993; 160:613–618.
Stoeckel, D, Pelton, A, Duerig, T. Self-expanding nitinol stents: material and design considerations. Eur Radiol. 2004; 14:292–301.
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C H A P T E R 7
Thrombectomy Devices
Steven Zangan and Brian Funaki
Catheter-directed thrombolysis (CDT) has advantages over surgical thrombectomy
in the treatment of venous or arterial thrombosis. Thrombolytic therapy avoids the
morbidity and mortality associated with conventional surgical techniques and
general anesthesia. It is less traumatic and causes less intimal damage compared
with surgical balloon thrombectomy. CDT has the distinct advantage of providing
both diagnostic information about associated vascular disease that may have incited
the occlusive event and the opportunity to treat coexistent lesions with angioplasty
and stenting. However, CDT can be time consuming and expensive, and response to
therapy may be nonuniform, especially in chronic occlusions. More importantly,
some patients are excluded from treatment because of contraindications to
anticoagulation. These shortcomings have driven the evolution of percutaneous
mechanical thrombectomy (PMT). PMT is particularly well suited for the treatment
of thrombosed hemodialysis access grafts, and most commercially available devices
have been approved by the U.S. Food and Drug Administration (FDA) for this
application. As device design continues to evolve, potential indications for PMT also
expand. Literature documenting e cacy in native arterial and bypass graft
1 2 3occlusion, deep venous thrombosis, pulmonary embolism, and transjugular
4 5intrahepatic portocaval shunt (TIPS) and portal vein thrombosis is mounting.
Indications
The use of PMT devices as 1rst-line therapy in the treatment of thrombosed
6hemodialysis access grafts is well established. These devices are particularly suited
to this application for a number of reasons. The thrombus is usually acute and small
in volume. Because thrombus is usually con1ned to the synthetic graft, the device
may only have to be activated within the access, eliminating any potential
endothelial damage. However, if thrombus extends into the native veins, the
thrombus can be removed with the same device. Finally, embolization of thrombus
fragment is better tolerated in the pulmonary arterial circulation than in a systemic
arterial bed.
Given the wide spectrum of PMT devices and their mechanism of action, clinical*
indications for their use are varied. Factors such as device length, device and target
vessel caliber, speed of thrombectomy, and device maneuverability are all important
considerations. Potential complications such as tolerance for endothelial injury,
embolization, and hemolysis must also be weighed. For these reasons, proper
indications of each particular device should be based on the manufacturer's
recommendations. Some manufacturers (e.g., AngioJet) have obtained FDA approval
for use of PMT devices in native coronary arteries, coronary bypass grafts, and all
infrainguinal arteries of the lower limbs.
Encouraging results have been reported in the following applications:
• Thrombosis in native artery
• Peripheral arterial bypass graft
7• Coronary artery thrombosis
• Proximal deep venous thrombosis
8• Iliocaval thrombosis
9• Central venous thrombosis in upper body
• Proximal pulmonary embolism
10• Visceral arterial thrombosis
• TIPS and portal vein thrombosis
Contraindications
The few absolute contraindications for the use of PMT are not application speci1c.
For example, like other endovascular procedures, PMT is contraindicated in infected
vascular access and in arterial occlusion of a nonviable limb. At minimum, before
pursuing PMT, the patient must be able to tolerate an endovascular procedure and
contrast medium. Additionally, if the lesion cannot be crossed, PMT is
contraindicated. Technical concerns related to the use of all PMT devices highlight
relative contraindications and should be considered in all applications before use.
Severe anemia is a relative contraindication to PMT because substantial
intraprocedural blood loss can be caused by these devices. This occurs both through
aspiration of blood through the catheter and by mechanical destruction of
11erythrocytes. Furthermore, substantial hemolysis can be detrimental in patients
with renal insu ciency because plasma free hemoglobin can incite renal tubular
damage. Patients with signi1cant cardiopulmonary disease, especially right-sided
heart failure, right-to-left shunts, and pulmonary hypertension, may not be good
candidates for venous or dialysis access PMT because of the potential embolization of
thrombus fragments during the procedure. Although most devices cause no apparent
clinically signi1cant vessel damage, the direct wall contact devices theoretically
cause more intimal damage. This consideration may be important when choosing the
appropriate device in a native vessel or conduit.Equipment
All PMT devices engage thrombus, fragment it, and most dispose of the eA uent. A
variety of approaches have been developed to achieve these goals (Table 7-1).
However, despite continued innovation, no ideal device exists. There seem to be as
many classi1cation schemes as there are devices. The following categories were
12introduced by Sharafuddin and Hicks and still provide an orderly framework to
review commonly used devices in current clinical practice:
TABLE 7-1
Mechanical Thrombectomy/Thrombolysis
Product Company Mode of Operation
Pronto Extraction Vascular Aspiration thrombectomy
Catheter Solutions
Diver CE Clot Medtronic Aspiration thrombectomy
Extraction
Catheter
Export AP
Aspiration
Catheter
Fetch Aspiration Medrad Aspiration thrombectomy
Catheter
Helix ClotBuster ev3 Rotational mechanical thrombectomy
Mechanical
Thrombectomy
Device
Rinspirator ev3 Infusion and aspiration thrombectomy
Thrombus
Removal System
Trellis Peripheral Covidien Isolated pharmacomechanical thrombolysis
Infusion System via a dispersion wire between two
occlusion balloons
AngioJet Medrad/Possis High-velocity water jets enclosed in the
catheter capture, microfragment, and
remove thrombus.
ThromCat Spectranetics Internal helix produces a vacuum andThrombectomy macerates thrombus while simultaneous
Product Company Mode of Operation
Catheter System flushing and extraction facilitate
thrombus removal.
Arrow-Trerotola Arrow Rotating wire fragmentation basket
Percutaneous macerates thrombus.
Thrombolytic
Device
Cleaner Rotational Argon Medical Sinusoidal vortex wire rotates and macerates
Thrombectomy thrombus.
System
D-Clot Artegraft Spiral conveyer shaft rotates and macerates
Thrombectomy thrombus while debris is aspirated
Catheter System through a sheath.
Merci Retrievers Concentric Mechanical thrombectomy with aspiration
Medical and proximal flow arrest via a
balloonguiding catheter (neurovasculature)
Penumbra System Penumbra Separator-assisted clot debulking and
aspiration (neurovasculature)
Straub Rotarex Straub Medical Rotating spiral creates a vacuum and
Catheter macerates thrombus, which is discharged
into a collection bag.
X-Sizer ev3 Mechanical thrombectomy with a helical
Thrombectomy cutter
Catheter System
Fogarty Adherent Edwards Mechanical thrombectomy via a
corkscrewClot Catheter Lifesciences shaped stainless steel cable
Fogarty Graft Edwards Mechanical thrombectomy via a double helix
Thrombectomy Lifesciences ring
Catheter
Xtraktor Xtrak Medical Mechanical thrombectomy via a rotating
Thrombectomy spiral shaft
Catheter
OmniWave OmniSonics Ultrasound-accelerated thrombolysis
Endovascular
System
EkoSonic Ekos Ultrasound-accelerated thrombolysis*
Endovascular
Product Company Mode of Operation
System
Acolysis Ultrasound Vascular Ultrasound-accelerated thrombolysis
Thrombolysis Solutions
System
• Percutaneous aspiration thrombectomy
• Pullback thrombectomy and trapping
• Recirculation mechanical thrombectomy
• Direct contact mechanical fragmentation
• Ultrasound
Percutaneous Aspiration Thrombectomy
Pronto Extraction Catheters (Vascular Solutions, Minneapolis, Minn.) are speci1cally
designed for arterial PAT. The Pronto family includes catheter models indicated for
removal of fresh soft emboli and thrombi from coronary and peripheral arteries
(Pronto V3 and LP), synthetic dialysis grafts and AV 1stulas (Pronto-Short), and
large vessels, veins, and arteries (Pronto 0.35 inch). A fashioned tip with a sloped
extraction lumen protects the vessel wall during extraction. The Diver CE Clot
Extraction Catheter and Export AP aspiration catheters (Medtronic, Minneapolis,
Minn.) and the Fetch Aspiration Catheter (Medrad, Warrendale, Pa.) are similar
devices.
Fabricated PAT systems are straightforward to institute. A guide catheter with a
gentle multipurpose curve is passed through an antegrade sheath, and the thrombus
is crossed with a guidewire. Then a thin-walled wide-lumen catheter with a
nontapered tip is advanced over the wire until it engages the thrombus. After the
wire is withdrawn, sustained suction is provided with a 30- or 60-mL syringe, and the
aspiration catheter is withdrawn through the sheath. This typically requires multiple
passes for adequate thrombus removal. Although successful as a salvage technique,
results are unpredictable, especially with mature clot, often because of the inability
to free thrombus from intrinsic and surrounding fibrosis.
Pullback Thrombectomy
The Green1eld transvenous pulmonary embolectomy catheter (Meditech/Boston
Scienti1c, Watertown, Mass.) is the prototype pullback thrombectomy device and
was introduced in 1969. Although bulky and di cult to maneuver, it was the 1rst
13catheter to show successful outcomes in the treatment of pulmonary embolism.
Sustained syringe suction is applied to a vacuum cup attached to a 12F double-lumen
balloon-tipped catheter.
Other clot-trapping devices (Intimax expandable access catheter, tulip
thrombectomy sheath, Ponomar transjugular clot trapper) remain experimental orare no longer widely available.
Recirculation Mechanical Thrombectomy
In recirculation mechanical thrombectomy, a hydrodynamic vortex is created by
high-speed rotation or retrograde Guid jets. This vortex generates high shear forces
that fragment and trap thrombus.
High-Speed Rotation Devices
Although it no longer has a signi1cant role, the Trac-Wright catheter (formerly
known as the Kensey catheter [Dow Corning Wright/Theratek International, Cordis,
Miami, Fla.]) merits mention as one of the original rotational recirculation PMT
devices. A blunt rotating cam was mounted on its tip and could be driven coaxially
at speeds up to 100,000 rpm.
The Amplatz Thrombectomy Device (ATD; Microvena, White Bear Lake, Minn.)
consists of a 6F or 8F catheter with a 1-cm long metallic capsule at its end. The
capsule houses an impeller that is driven coaxially up to 150,000 rpm by high air
pressure (50-100 psi). Negative pressure at the catheter tip draws adjacent thrombus
into the end hole of the capsule, where it becomes fragmented by the rotating blades.
The fragmented thrombus is then expelled radially through two side holes, and
cleaved particles are repeatedly reaspirated, further macerating the thrombus. The
thrombus is broken down to small particles of which 98.8% to 99.2% are less than 13
14µm. The remaining particles measure 13 to 1000 µm. The driveshaft extends
through a Y connecter at the proximal end of the catheter, allowing infusion of
contrast agent or adjunctive 1brinolytic agents. Although the ATD has gained
acceptance in multiple clinical applications, its poor steerability and the tendency of
the rotating cable to break when activated over acute angles are limitations. The 6F
catheter shaft is made with a polyether block amide (Pebax) that promises better
torque control. The current iteration of the ATD is the Helix ClotBuster Mechanical
Thrombectomy Device (ev3, Plymouth, Minn.) (Fig. e7-1). It represents a modi1ed
7F version of the ATD and is reportedly more tolerant of acute angles. The device is
powered by compressed air or nitrogen and operated via a reusable pedal-operated
foot control. Additionally, the impeller is directed perpendicular to the vessel wall
(so-called TurboWash Wall Washing Technology), which is designed for improved
removal of adherent mural thrombus without vessel wall contact. The Helix
ClotBuster is available in both 75- and 120-cm working lengths. It is approved for
use in both dialysis grafts and native vessel dialysis fistulae.FIGURE E7-1 Helix ClotBuster Thrombectomy Device.
Miniature impeller creates a recirculating vortex. (Courtesy ev3,
Plymouth, Minn.)
The Rinspirator Thrombus Removal System (ev3, Plymouth, Minn.) is a single-use
hand-activated device that has a central lumen for aspiration of debris and infusion
holes at the distal end to direct a rinsing spray. It simultaneously rinses and aspirates
thrombi from vessels via the use of two syringes. The concurrent rinsing and
aspiration is said to promote reperfusion. For peripheral applications, it is available
in both 65- and 135-cm lengths. The catheters are 7F and work over 0.014-inch
guidewires.
The Trellis Peripheral Infusion System (Covidien, Mans1eld, Mass.) is an
over-thewire device consisting of two occlusion balloons separated by 10 to 30 cm. The area
between the balloons has multiple holes for drug infusion. After the device is
advanced to the thrombosed segment, the standard 0.035-inch guidewire is removed
from the central channel, and a sinusoidal-shaped nitinol wire attached to a
handheld drive unit is inserted and secured via a Luer-Lok system. The balloons are
inGated, and thrombolytics are administered between the balloons while oscillation
of the dispersion wire increases clot surface area to enhance the speed of lysis. The
contact point of the wire can be shifted longitudinally during the procedure so therotating wire contacts a diOerent portion of the thrombus adherent to the wall. An
aspiration port facilitates removal of remaining thrombolytic and lysed debris. Both
6F and 8F catheters are available.
Retrograde Fluid Jet Devices
Hydrodynamic Gow–based thrombectomy devices use high-velocity retrograde saline
jets to create a negative pressure gradient directed toward the catheter lumen. The
jets not only create a localized low-pressure zone via the Bernoulli eOect but also
serve to macerate thrombus and drive evacuation of debris through the catheter.
The AngioJet (Medrad, Warrendale, Pa.) rheolytic thrombectomy system consists
of three major components: a single-use catheter ranging in size from 4F to 6F, a
single-use pump bag assembly, and a nondisposable motorized drive unit. The
catheters have two lumens; the large primary lumen allows debris evacuation and
guidewire passage, and a small pro1led stainless steel tube supplies the pressurized
perfusate. The smaller tube projects beyond the catheter tip and forms a transverse
loop, allowing direction of the Guid jet retrograde into the evacuation lumen (Fig.
e7-2). The pump bag assembly consists of a high-pressure saline supply line and
disposable pump and an eA uent evacuation line and collection bag. The pump
operates at 8500 psi, allowing retrograde jets to reach speeds of 450 km/h. This
resultant low-pressure zone (≤600 mm Hg) causes a powerful vacuum eOect (Fig.
e7-3). Unique to the AngioJet is the nondisposable drive unit that maintains the
balance of saline delivery and thrombotic debris outGow. Sensors monitoring for air
bubbles, appropriate pressure, and eA uent line patency help ensure system
performance. The unit is driven via foot pedal. A “Power Pulse Delivery” kit consists
of a Y adapter and one-way stopcock to allow convenient concomitant
administration of 1brinolytics. Two solution bags are prepared, one with saline
alone and one with a lytic agent added. With the stopcock in the “oO” position and
the outGow port occluded, the catheter eOectively becomes a one-way infusion
system. A variety of application-speci1c (coronary, dialysis access, peripheral
arterial) models are available for both 0.014-inch and 0.035-inch systems, with
working lengths ranging from 50 to 140 cm.FIGURE E7-2 AngioJet. Saline jets travel backward at high
speed to create a low-pressure zone, causing a powerful
vacuum effect. (Courtesy Medrad, Warrendale, Pa.)
FIGURE E7-3 AngioJet. Thrombus is drawn into catheter,
where it is fragmented by the jets and evacuated from body.
(Courtesy Medrad, Warrendale, Pa.)
The ThromCat Thrombectomy Catheter System (Spectranetics, Colorado Springs,
Colo.) uses a 4.5F 150-cm catheter with an internal helix, three saline infusion holes,
and 1ve radial extraction ports. It is connected to an infusate and driven with a
onebutton handheld control. A powerful vacuum (700 mmHg) draws thrombus into the
catheter, where it is macerated by an internal helix rotating at 95,000 rpm.
Simultaneous Gushing and extraction facilitate thrombus removal. The helix is
enclosed, and there is no direct vessel wall contact. The catheter works over a
0.014inch guidewire and is indicated for mechanical removal of thrombus in synthetichemodialysis access grafts and native vessel dialysis fistulae.
Direct Contact Mechanical Fragmentation
Direct contact, or wall contact, thrombectomy devices use wires or brushes to achieve
clot maceration. Because there is usually no signi1cant hydrodynamic recirculation,
larger fragments are released. However, the focused contact action appears to oOer
the most complete thrombectomy. This class can be further subdivided into those
devices that use mechanical fragmentation alone and those that use concomitant
active thrombus aspiration to clear resultant debris.
The Arrow-Trerotola Percutaneous Thrombolytic Device (PTD; Arrow
International, Reading, Pa.) was designed for declotting dialysis access and is FDA
approved for use in both arteriovenous 1stulas and synthetic grafts. The PTD kits
come complete with a 5F or 7F over-the-wire (0.025-inch) catheter, a handheld
battery-operated disposable rotator drive unit, and an introducer sheath. The device
is advanced to the thrombus, and a self-expanding 9-mm nitinol fragmentation
basket is deployed by withdrawing the catheter (Fig. e7-4). The motor spins the
basket, which conforms to variable-diameter vessel/graft walls, at 3000 rpm, and
thrombus is macerated into fragments smaller than 3 mm in diameter. Although the
device itself is nonaspirating, debris can be manually aspirated through the outer
sheath. Both 65- and 120-cm catheters are available.FIGURE E7-4 Arrow-Trerotola PTD (percutaneous thrombolytic
device). Expandable fragmentation basket with a soft flexible tip.
(Courtesy Arrow International, Reading, Pa.)
The Cleaner Rotational Thrombectomy System (Argon Medical, Plano, Tex.) uses
an atraumatic wall-contact sinusoidal vortex wire driven by a battery-operated
handheld unit. It is indicated for use in synthetic dialysis grafts and native vessel
1stulae. It does not use a guidewire and passes through a 6F sheath. Both 65- and
135-cm lengths are available.
The D-Clot Thrombectomy Catheter System (Artegraft, North Brunswick, N.J.)
consists of a Gexible spiral conveyer shaft rotating within a plastic sheath. The shaft
has a small, Gexible, curved agitator that extends out of the sheath. As the agitator
rotates (>10,000 rpm), it creates a pumping action that holds thrombus against the
tip until it is 1nely macerated. Debris is aspirated into the sheath and conveyed by
the rotating spiral shaft through the sheath to a collection line connected to a
disposable vacuum syringe. The 40-cm catheter works through a 6F sheath and over
a 0.035-inch wire. It is indicated for use in nonautogenous grafts.
The Merci Retrievers (Concentric Medical, Mountain View, Calif.) are a family of
corkscrew-shaped catheters designed for mechanical thrombectomy in the
neurovasculature. They consist of nitinol wire that maintains a linear orientation
when delivered through a speci1c Merci MC18L 3F microcatheter. When deployed,the Retriever returns to its coiled shape to engage and retrieve the clot. They are
designed to be deployed distal to the clot to apply distal force for removing resistant
clot. The V series retrievers are designed such that the proximal loops stretch to
engage the clot, while the two distal loops remain intact to capture the clot. There
are 10 Merci Retrievers available to match vessel size. They were 1rst approved by
the FDA in 2004 and are indicated for removing thrombus in ischemic stroke in
patients who are not candidates for or who have failed thrombolytic therapy. They
are also used for retrieval of foreign bodies.
The Penumbra System (Penumbra, Alameda, Calif.) uses separator-assisted clot
debulking and aspiration for revascularization of patients with acute ischemic stroke
secondary to intracranial large vessel occlusive disease. It has three main
components: a reperfusion catheter with a separator and a thrombus-removal ring.
All components of the system are deliverable via a 6F standard guide catheter. The
reperfusion catheter is deployed to the site of occlusion, the guidewire is removed,
and the separator is advanced through the reperfusion catheter. An aspiration pump
generates a vacuum, and clot burden is reduced by a continuous aspiration debulking
process facilitated by advancing and withdrawing the separator through the
reperfusion catheter into the proximal end of the clot. If thrombus remains, direct
retrieval of the thrombus using a removal ring under Gow-arrest conditions (via a
proximal balloon guide catheter) can be attempted.
The Straub Rotarex catheter (Straub Medical, Wangs, Switzerland) consists of two
superimposed cylinders with side slits. The inner cylinder is 1xed to the catheter
shaft, and the outer cylinder to a rotating spiral running through the entire length of
the catheter and driven by a reusable electric motor at 40,000 to 60,000 rpm. At the
tip, the spiral communicates with the vessel lumen through two oval slits. The
rotation of the spiral creates a vacuum (−435 mm Hg) at the catheter tip, and the
thrombus is pulled through the cutting slits. The fragments are transported by the
spiral to the proximal side port and discharged into a collecting bag. Rotation can be
started manually or by footswitch. A control unit regulates the speed of the motor to
obtain optimal rotation speed. The Rotarex is an over-the-wire system (0.018-inch)
and is available in both 6F and 8F sizes. The catheter is designed for use in arteries
and grafts. Use in veins is not recommended owing to the high negative pressure
created by the vacuum.
The X-Sizer Thrombectomy Catheter System (ev3, Plymouth, Minn.) features a
helical cutter that rotates at 2100 rpm. The cutter is housed in the tip of a 6F or 7F
catheter (Fig. e7-5). Kits include vacuum collection bottles and tubing for removal of
debris. The X-Sizer catheter is 135 cm in length and compatible with 0.014-inch
guidewires.*
FIGURE E7-5 X-Sizer Thrombectomy Catheter System. The
screw rotates, draws in thrombus material, and shears it off.
(Courtesy ev3, Plymouth, Minn.)
The Fogarty adherent clot catheter (Edwards Lifesciences, Irvine, Calif.) features a
spiral-shaped, latex-covered stainless steel cable that assumes a corkscrew shape
when retracted. It is indicated for use in native arteries and synthetic grafts. The
Fogarty graft thrombectomy catheter (Edwards Lifesciences, Irvine, Calif.) consists of
a Gexible wire coil at the distal end that expands when retracted to form a double
helix ring. Acting as a ring stripper, the ring forms a plane between the graft and
thrombus to clear adherent material.
The Xtraktor Thrombectomy Catheter (Xtrak Medical, Salem, N.H.) contains a
rotatable spiral shaft that extends beyond a 6F plastic sheath as a Gexible curved tip.
The tip spins to macerate thrombus and remove adherent thrombus from the graft
wall. As the particles are formed, they are simultaneously aspirated into the catheter
sheath and conveyed out of the vessel by the rotating spiral shaft.
Use of a rotatable pigtail catheter (Cook, Bloomington, Ind.) for thrombus
15fragmentation was 1rst described to treat pulmonary embolus, and promising
results have been reported for recanalization of thrombosed dialysis access. In this
technique, a high-torque catheter with a pigtail tip is utilized through a compatible
sheath. Initially the catheter is introduced and positioned with a guidewire exiting
the end hole. To fragment thrombus, the guidewire is retracted and then directed
through the most proximal side hole of the catheter, allowing recoil of the pigtail tip.
A hydrophilic guidewire with a curved tip will help facilitate this maneuver. The wire
then serves as a 1xed rotating axis crossing the embolic occlusion. The catheter shaft
is then rotated manually by twisting it between the thumb and index 1nger as it is
slowly advanced and withdrawn over the stationary guidewire. Speeds of up to
120 rpm can be expected with this technique. The procedure is continued until
satisfactory thrombus fragmentation is achieved. The guidewire is then repositioned
through the end hole, and the pigtail catheter can be removed. This technique is
attractive because it has proven e cacious, rapid, and safe without the complexity
and cost of more technically sophisticated devices.Ultrasound
Ultrasound-based thrombectomy devices achieve clot fragmentation by producing
cavitation bubbles around the catheter active zone. During the negative part of the
ultrasonic cycle, the pressure around the wire falls below the vapor pressure of the
surrounding tissue, causing the formation of microbubbles. When those microbubbles
implode, they cause powerful shear forces that break up fibrin.
The OmniWave Endovascular System (OmniSonics Medical Technologies,
Lakewood, N.Y.) is intended for use in the peripheral vasculature for removal of
thrombus and infusion of physician-speci1ed Guids. The system includes a generator,
handpiece, and the OmniWave Endovascular Catheter. The generator sends an
electronic signal to the handpiece, which converts the signal to low-power ultrasonic
energy. This is transmitted down the wire, which generates a transverse ultrasonic
wave that travels 360 degrees around its 10-cm active zone. The wire has been tuned
to oscillate at a frequency capable of resolving targeted materials such as 1brin
while leaving the surrounding vasculature and soft tissues unaOected (Fig. 7-6).
Bench data from OmniSonics suggest that treatment of a 30-cm clot only requires
about 10 minutes of activation. The monorail catheter is 7F and 0.018-inch wire
compatible. The OmniWave Endovascular System obtained FDA clearance for
treatment of thrombus in the peripheral vasculature and infusion of
physicianspecified fluids in September 2007.
FIGURE E7-6 OmniWave Endovascular System. Catheter
system generates transverse ultrasonic waves that selectively
microfragment fibrin found in thrombus. (Courtesy OmniSonics
Technologies, Inc.)
The EkoSonic Endovascular System (Ekos, Bothell, Wash.) simultaneously delivers*
ultrasound and thrombolytics to target clot. Theoretically, the high-frequency,
lowpower ultrasonic energy loosens and thins the clot's 1brin structure, allowing
thrombolytic agents to access more receptor sites. At the same time, ultrasonic
pressure forces drug deeper into the clot so it does not escape downstream. It does
not fracture red blood cells, thereby limiting potential renal injury and adenosine
release. The standard system is indicated for use in the peripheral and pulmonary
vasculature. It works through a 6F sheath and over a 0.035-inch guidewire. The
EkoSonic SV Endovacular System is also indicated for the coronary and
neurovasculature. It consists of a 3F microcatheter with a central lumen and the
ultrasound element at the tip. It works over a 0.014-inch guidewire.
The Acolysis Ultrasound Thrombolysis System (Vascular Solutions, Minneapolis,
Minn.) was designed to treat arterial lesions. Although 1rst used in the coronary
16 17circulation, it may be e cacious in peripheral arteries, hemodialysis access
18grafts, and 1stulas. An intravascular probe is placed at the occlusion, and
ultrasound energy creates a Guid vortex that fragments clot and draws the particles
toward the probe tip, where cavitation produces subcapillary-sized particles and
limited heat. The catheter is compatible with a 7F guide catheter and has a working
length of 78 cm. It uses a 0.018-inch guidewire. The Acolysis is currently sold in
international markets and is in clinical planning stages in the United States.
Technique
Anatomy and Approach
Before using any thrombectomy device, it is important that the radiologist and all
technical support staO thoroughly understand how to properly prepare the patient,
use the device, and troubleshoot the system. Most manufacturers provide competency
assessment programs that include videotapes, computerized modules, technical
manuals, hands-on practical training sessions, and certi1cation examinations to
ensure that each caregiver possesses the appropriate skills.
Technical Aspects
Each device has unique characteristics and will be used in a variety of clinical
applications. Speci1cs concerning the technical aspects of each individual catheter
are beyond the scope of this text. The reader is referred to the manufacturers'
technical guidelines for further details. Some general rules, however, apply to most
devices and applications. Most require standard angiographic tools such as a
vascular sheath and guidewire. These are often included with the device kits.
Anticoagulation with heparin is typically indicated to prevent re-thrombosis during
the procedure. The devices are powered by conventional power injectors, a handheld
motor, or a special external device. The procedures are well tolerated under
conscious sedation. The strict periprocedural patient monitoring required in all*
*
interventional procedures is equally important during PMT procedures (Box e7-1).
Box
e71 Percutaneous Mechanical Thrombectomy
Periprocedural Considerations
• Conscious sedation is usually sufficient.
• Consider antibiotic administration in susceptible patients.
• Use nitroglycerin as intraarterial 200- to 300-µg boluses for arterial
spasm.
• Administer 3000- to 5000-unit intravenous (IV) heparin bolus before
thrombectomy.
• Use of fibrinolytics (“combination therapy”) may be advantageous.
• Strictly monitor vital signs with pulse oximetry and electrocardiography.
Controversies
Given the number of available devices and variety of their mechanism of action, it is
not surprising that controversy exists concerning which catheter is the safest and
most e cacious. The ideal device is easy to operate and maneuver, is rapidly
e cacious regardless of vessel size or thrombus age, and lacks complications.
Clearly, this device does not exist. However, as experience grows, the
interventionalist will be able to choose the most appropriate device for each speci1c
indication.
Placement of a vena cava 1lter before lower extremity deep venous thrombosis
19-21thrombolysis to combat embolization has also been debated. Embolic protection
devices have also been introduced to be used during thrombectomy (see Embolic
Protection Devices).
Because direct wall contact devices have the potential to cause more vascular
endothelial damage than noncontact devices, there is debate about whether their use
22is better suited to grafts than native vessels. One study compared the damage done
by the Arrow-Trerotola and Castaneda Brush to a Fogarty balloon. The Castaneda
Brush caused the least vascular injury.
Not only are there controversies about which device is best, there are also
6variations in how the devices are used. For example, in the treatment of
thrombosed hemodialysis grafts, the venous outGow stenosis is usually treated after
thrombectomy. The stenosis helps trap thrombus in the graft, allowing easier
removal and preventing embolization. However, others have advocated treating the*
*
*
stenosis first. By improving outGow, there is less intragraft turbulence,
decompression into the venous system, and subsequently, a lower likelihood of
retrograde embolization into the arterial system.
Outcomes
No single PMT device has emerged as superior. Each manufacturer claims bene1ts
unique to their catheters owing to the speci1c mechanism of action, although these
are often merely theoretical advantages and have not been su ciently validated in
clinical trials.
Multiple studies have demonstrated that all PMT devices can achieve excellent
technical success rates. When evaluating studies, however, it is important to consider
them in appropriate clinical context. Early experiments typically evaluate in vitro
eOectiveness of a device followed by in vivo eOectiveness in an animal model.
Although information gained from these studies is often valuable, the models are not
completely physiologic, and translation of the 1ndings to daily clinical use must be
made with caution. Furthermore, technical success achieved in patients often cannot
be translated into long-term patency.
In the treatment of occluded hemodialysis grafts and 1stulas, excellent technical
success is the norm and can approach 95%, although 3-month average primary
23patency rates remain disappointing. Long-term patency is dependent on successful
treatment of coexistent stenosis and complete removal of the arterial plug.
A large multicenter study demonstrated the e cacy of PMT in the treatment of
acute limb ischemia due to peripheral arterial occlusions. Partial to complete
thrombus removal was obtained in 92% of patients. The 1-month mortality and
amputation rates of 7% and 4% compare favorably with traditional results for open
24surgery or thrombolysis.
E cacy of multiple PMT catheters in the treatment of deep venous thrombosis has
25been shown. Procedural success was achieved in 82% of cases.
Complications
Procedure-related complications of mechanical thrombectomy, such as contrast
nephropathy and puncture site hematoma or pseudoaneurysm, are common to all
endovascular procedures and are managed in standard fashion. However, PMT
devices have been associated with speci1c complications that deserve consideration.
A potential for signi1cant blood loss exists with all devices, though systems that use
aspiration or the Venturi eOect are especially vulnerable. Therefore, it is
recommended that device activation time and overall Guid balance during the
procedure be strictly monitored. The traumatic hemolytic eOect of these devices
further exacerbates anemia. Furthermore, hemolysis can be potentially nephrotoxicbecause of the release of free hemoglobin.
There will undoubtedly be embolization of debris during endovascular
thrombectomy procedures. The clinical signi1cance of microembolization
(angiographically occult fragments) and macroembolization (angiographically
visible fragments) during PMT depends greatly on the reserve of the target
circulation at risk. Small pulmonary emboli are usually well tolerated, although a
26measurable decrease in arterial oxygen saturation can result. It follows that
patients with cardiopulmonary disease receive special attention during these
procedures. Peripheral and mesenteric arterial beds are less forgiving, and the use of
concomitant 1brinolytics may be warranted in these situations. Other technical
factors such as avoiding primary traversal of the clot and the use of a gradual
27leading-to-trailing approach during thrombectomy are prudent. The use of
occluding balloons, special embolic protection devices, discretionary use of vena
cava 1lters, and peripheral blood pressure cuOs also may decrease embolic
complications.
Vascular endothelial injury can occur during PMT, especially when using a wall
contact device. Although frank vessel perforation can occur, most injuries are minor
and self-limited. Experience with Fogarty embolectomy catheters suggests that these
vascular lesions can promote re-thrombosis and atherosclerosis and accelerate
28hyperplastic intimal changes. Anticoagulation with heparin and/or antiplatelet
agents is typically necessary to avoid re-thrombosis during PMT. Most importantly,
the inciting lesion or event must be adequately treated to promote long-term
patency.
Postprocedural AND Follow-Up Care
Postprocedural and follow-up care vary greatly based on the clinical indication for
which mechanical thrombectomy was performed. Standard principles of patient care
should be followed as in all interventional procedures. Patients typically return to
unmonitored Goor beds unless CDT is needed. In the case of thrombosed dialysis
access, PMT devices and other catheters are usually exchanged for high-Gow vascular
sheaths, allowing immediate hemodialysis treatment. Long-term anticoagulation may
be beneficial in selected cases.
Key Points
• Percutaneous mechanical thrombectomy uses mechanical energy to
dissolve, fragment, and aspirate intravascular thrombus.
• The goal of this therapy is to combine the speed and consistency of
surgical thrombectomy with the minimally invasive elegance and safety
of catheter-directed pharmacologic thrombolysis.• Innovation in device design has resulted in a myriad of mechanical
thrombectomy devices. These devices vary in their mechanism of action,
size, cost, maneuverability, and safety.
• As experience with each device grows, efficacy in a wide variety of
applications continues to be demonstrated.
▸ Suggested Readings
Lin, PH, Ochoa, LN, Duffy, P. Catheter-directed thrombectomy and thrombolysis for
symptomatic lower-extremity deep vein thrombosis: review of current
interventional treatment strategies. Perspect Vasc Surg Endovasc Ther. 2010;
22:152–163.
Müller-Hülsbeck, S, Jahnke, T. Peripheral arterial applications of percutaneous
mechanical thrombectomy. Tech Vasc Intervent Radiol. 2003; 6:22–34.
Sharafuddin, MJ, Hicks, ME. Current status of percutaneous mechanical
thrombectomy: I. General principles. J Vasc Interv Radiol. 1997; 8:911–921.
Sharafuddin, MJ, Hicks, ME. Current status of percutaneous mechanical
thrombectomy: II. Devices and mechanisms of action. J Vasc Interv Radiol. 1998;
9:15–31.
Sharafuddin, MJ, Hicks, ME. Current status of percutaneous mechanical
thrombectomy: III. Present and future applications. J Vasc Interv Radiol. 1998;
9:209–224.
Stainken, BF. Mechanical thrombectomy: basic principles, current devices, and future
directions. Tech Vasc Intervent Radiol. 2003; 6:2–5.
Vesely, TM. Mechanical thrombectomy devices to treat thrombosed hemodialysis
grafts. Tech Vasc Intervent Radiol. 2003; 6:35–41.
References
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a hydrodynamic catheter: results from a prospective, multi-center trial.
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thrombolysis with adjunctive mechanical thrombectomy. J Vasc Interv Radiol.
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3. Fava, M, Loyola, S, Huete, I. Massive pulmonary embolism: treatment with
the Hydrolyzer thrombectomy catheter. J Vasc Interv Radiol. 2000; 11:1159–
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4. Müller-Hülsbeck, S, Link, J, Höpfner, M, et al. Rheolytic thrombectomy in an
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13. Greenfield, LJ, Kimmell, G, McCurdy, WC. Transvenous removal or
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9:347–352.
14. Yasui, K, Oian, Z, Nazarian, GK, et al. Recirculation-type Amplatz clot
macerator: determination of particle size and distribution. J Vasc Interv
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15. Schmitz-Rode, T, Janssens, U, Schild, HH, et al. Fragmentation of massive
pulmonary embolism using a pigtail rotation catheter. Chest. 1998;
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16. Rosenschein, U, Roth, A, Rassin, T, et al. Analysis of coronary ultrasound
thrombolysis endpoints in acute myocardial infarction (ACUTE trial): results
of the feasibility phase. Circulation. 1997; 95:1411–1416.
17. Goyen, M, Kroger, K, Buss Rudofsky, G. Intravascular ultrasound angioplasty
in peripheral arterial occlusion. Acta Radiol. 2000; 41:122–124.
18. Wildberger, JE, Schmitz-Rode, T, Haage, P, et al. Ultrasound thrombolysis in
hemodialysis access: in vitro investigation. Cardiovasc Intervent Radiol. 2001;24:53.
19. Lam, R, Bush, RL, Lin, PH, et al. Early technical and clinical results with
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22. Castañeda, F, Li, R, Patel, J, et al. Comparison of three mechanical thrombus
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219:153–156.
23. Vorwerk, D, Schürmann, K, Müller-Leisse, C, et al. Hydrodynamic
thrombectomy of haemodialysis grafts and fistulae: results of 51 procedures.
Nephrol Dial Transplant. 1996; 11:1058–1064.
24. Ansel, GM, George, BS, Botti, C, et al. Rheolytic thrombectomy in the
management of limb ischemia: 30 day results from a multicenter registry. J
Endovasc Ther. 2002; 9:395–402.
25. Vendantham, S, Vesely, TM, Parti, N, et al. Lower-extremity venous
thrombolysis with adjunctive mechanical thrombectomy. J Vasc Interv Radiol.
2002; 13:1001–1008.
26. Cervera-Ceballos, JJ, Sakinis, AK, Pozza, CH, et al. Mechanical
thrombectomy of the inferior vena cava: an experimental study [Abstract].
Radiology. 1995; 196:73–77.
27. Rilinger, N, Gorich, J, Scharrer-Palmer, R, et al. Short-term results with the
use of the Amplatz thrombectomy device in the treatment of acute lower limb
occlusions. J Vasc Interv Radiol. 1997; 8:343–348.
28. Bowles, CR, Olcott, C, Pakter, RL, et al. Diffuse arterial narrowing as a result
of intimal proliferation: a delayed complication of embolectomy with the
Fogarty balloon catheter. J Vasc Surg. 1988; 7:487–494.


C H A P T E R 8
Embolic Protection Devices
Bhaskar Ganai and Sumaira Macdonald
Following the introduction of endovascular techniques to treat extracranial carotid disease, the
seminal challenge was to compete e ectively with the tried and tested surgical alternative, carotid
endarterectomy (CEA), which had largely already undergone and completed re nements in
1,2technique that improved clinical outcomes. Perhaps the biggest challenge was the e ective
control of the embolic burden of carotid artery stenting (CAS).
It is known that periprocedural thromboembolic events occur frequently as a result of
3manipulation of guidewires, balloons, and stents. The consequences and clinical manifestations of
these emboli are dependent on both size and number of emboli, on the temporal pattern of
embolization, and on target organ sensitivity to emboli and ischemia. In the carotid territory, distal
emboli may result in cerebral ischemia, stroke, and in the longer term, possibly cognitive decline
and dementia, although the supporting evidence for this contention is not derived from the clinical
4setting of CAS. In the lower limb, distal embolization can result in critical limb ischemia and
amputation through loss of runo vessels. Use of embolic protection devices (EPDs) is most widely
studied in the carotid circulation, and many of the device innovations and advances relate to CAS.
Evidence of Improved Clinical Outcomes with Protected Carotid
Artery Stenting
Although there are no randomized trial data based on clinical outcomes to advocate their use, each
type of device has been shown to capture macroemboli, implying additional protection of the brain
during CAS when they are used. A systematic review reported that the relative risk of all stroke
(0.59 in 24 studies, with concurrently reported protected and unprotected data) was signi cantly
5lower (I
Embolic Burden of Carotid Artery Stenting
Macroemboli
Thromboemboli may result from catheterization of the arch, great vessel origins, and
endovascular manipulation of the carotid bifurcation lesion itself. Up to 20% to 40% of strokes in
the CAPTURE (Carotid Acculink/Accunet Post-Approval Trial to Uncover Unanticipated or Rare
6Events) registry resulted from access di6 culties during cannulation of the aortic arch vessels.
Access problems appear to be related to operator experience. In EVA3S (Endarterectomy Versus
Angioplasty in Patients with Severe Symptomatic Carotid Stenosis), the French trial of CAS versus
CEA in purely symptomatic patients, 5% of CAS patients were converted intraoperatively to CEA
7owing to access problems, with 15% of these patients having a stroke before CEA. The trial has
been widely criticized for the relative inexperience of those operators performing CAS. An elegant
8Italian study sought to evaluate risk for CAS strati ed by procedural phase. Two distinct timelines





were identi ed: 195 CAS procedures were performed between 2001 and 2003, and 432 CAS
procedures were performed between 2004 and 2006. Five major procedural steps were considered:
Phase 1, aortic arch and great vessel catheterization; Phase 2, placement of the EPD (mostly of the
lter type, the Mo.Ma proximal EPD being used in just over 7% of cases); Phase 3, stent/balloon
phase, to include EPD retrieval for the majority of devices used (i.e., distal lters); Phase 4, the rst
24 hours “o table”; and Phase 5, the late postinterventional period (i.e., 24 hours to 30 days).
Four of ten major strokes occurred during Phase 1 (i.e., catheterization of the arch and great vessel
origin ipsilateral to the lesion to be treated at the carotid bifurcation). With time (and experience),
the major stroke/death rate fell from 3.1% to 0.9%. (P = 0.047) between the early and later
timeframes.
Microemboli
Microemboli are de ned as those elements (gaseous or particulate) measuring less than 1 mm in
diameter. They may be generated by:
• Agitated contrast, resulting primarily in gaseous microemboli during the drawing up of contrast
9and its injection
• Catheterization of the arch
• Catheterization of the great vessel origin
• Endovascular manipulation of plaque
• Plaque prolapse through stent struts
• Platelet aggregates on stent struts following stent deployment prior to stent endothelialization
Assessing Microemboli
Microembolic signals (MES) can be assessed on transcranial Doppler (TCD) of the middle cerebral
artery and may be applied either ipsilateral to the lesion being treated or bilaterally. Cellular
edema on di usion-weighted magnetic resonance imaging (DWMRI) of brain, manifesting as new
white hyperintense lesions, are a further marker of cerebral insult. Bright lesions that have matched
restricted di usion on apparent di usion coe6 cient (ADC) maps can date the cerebral insult as
acute (i.e., up to 7-10 days of age). DWI hyperintensities have been used to compare the magnitude
of the embolic burden between di erent carotid interventional strategies. During carotid stenting,
MES counts are generally increased in three phases: predilation, stent deployment, and
10postdilation, with the highest counts during stent deployment or aggressive postdilation.
Although MES and DWI hyperintensities are useful for research purposes, representing a proxy for
neurologic injury that may or may not be subclinical, the fate and clinical relevance of these
11findings is incompletely understood.
Differential Control of Microembolic Burden of Carotid Artery Stenting
The International Carotid Stenting Study (ICSS) was a one-to-one randomized comparison of CAS
12versus CEA in standard-risk patients in a U.K.-based international trial. In a substudy of the ICSS
trial, 231 patients had preprocedural, 1 to 3 days postprocedural, and 1-month postprocedural
13DWMRI scans to compare the microembolic penalty following CEA to that of CAS. The new white
lesion rate was 50% for largely lter-protected CAS and 17% for CEA. There were fewer larger
lesions following CEA, and many more smaller lesions for CAS (i.e., the same mean volume of brain
was a ected by CAS and CEA). Five percent of lesions were in the territory contralateral to the
carotid artery being treated in CAS patients, compared with 1% of contralateral lesions following
CEA. In 33% of lesions detected on postprocedure DWMRI in CAS patients, the lesions were evident
on Fuid attenuation inversion recovery (FLAIR) imaging at 30 days, implying some level of






permanent injury, compared with 8% for CEA patients. Accepting this, an analysis of cognitive
function as a further subset analysis of the ICSS dataset revealed no difference in neuropsychometry
14between treatment limbs, despite an excess of DWMRI lesions following CAS.
Within the DWMRI substudy, ve centers used lter-type EPDs in the majority, and two centers
did not routinely employ EPDs. The new white lesion rate was 73% for lter protection and 34%
for unprotected CAS (P = 0.019).
Two small randomized trials have sought to compare control of the microembolic burden with the
Mo.Ma proximal EPD and filter protection. The first (recruiting 53 patients with lipid-rich plaque as
assessed on computed tomographic angiography [CTA]) demonstrated signi cantly more MES with
lters than with the Mo.Ma: 101 ± 53 versus 22.5 ± 19 and substantially more DWMRI new
lesions with lters. The di erence in this endpoint did not reach statistical signi cance because the
15study was underpowered for the DWI surrogate (N = 45). The latest trial recruited 62 patients
and demonstrated an 87.1% new white lesion rate following lter-protected CAS and a 45.2% new
white lesion rate following Mo.Ma-protected CAS, and there were signi cant di erences with
respect to mean number of lesions and mean volume of brain a ected in favor of the Mo.Ma. This
di erential in favor of proximal protection was maintained regardless of either symptom or
16octogenarian status.
Prospective cohort analyses show comparable and consistent discrepancies between proximal and
distal lter devices in favor of proximal devices. In a prospective analysis of 21 patients
undergoing Mo.Ma-protected CAS and 21 undergoing lter-protected CAS, Schmidt et al.
17demonstrated a total MES count of 57 ± 41 for the Mo.Ma device and 196 ± 84 for the filter (P
In the DESERVE (Di usion-Weighted MRI-Based Evaluation of the E ectiveness of Endovascular
Clamping During Carotid Artery Stenting with the Mo.Ma Device) study evaluating the Mo.Ma in a
18multisite E.U. registry of 127 patients, the new white lesion rate was 30%.
A small but elegant nonrandomized study compared CEA with lter-protected and Fow reversal–
19protected CAS via a femoral route in 42 patients (Table e8-1).
TABLE e8-1
Comparison of MES for CEA, Filter-Protected CAS, and Flow Reversal–Protected CAS
Procedure N Incidence of MES Procedural Stage
CEA 15 15.3 (±22) Post procedure
Filter-protected CAS 20 319 (±110.3) Throughout protection
CAS with flow reversal 7 184.2 (±110.5) Pre-protection
CEA versus filter-protected CAS P = 0.001
CEA versus flow reversal protected CAS P = 0.007
Flow reversal versus filter protection P = 0.05
C A S , Carotid artery stenting; C E A , carotid endarterectomy; M E S , microembolic signals.
The stage of vulnerability of the brain with di erent carotid interventional strategies requires
special mention. Flow reversal is associated with signi cantly fewer MES than lter protection, but
the brain is vulnerable pre-protection for Fow reversal, implying the embolic penalty posed by
catheterization of the arch and great vessels. If one addresses the important limitation of carotid
stenting via the femoral route, CAS might start to approximate the excellent control of microemboliafforded by CEA.
PROOF (Embolic Protection System: First-in-Man Study) was an analysis of the MICHI system
(high Fow rate reversed Fow via a mini-incision in the ipsilateral CCA, thereby avoiding
catheterization of the arch and great vessel origins). A subgroup of patients (n = 31) were
examined with DWMRI at 24 to 48 hours post procedure, and the scans were read by two
independent neuroradiologists in the United States. New ischemic lesions were identi ed in 16% of
patients, comparing favorably to the CEA arm of the ICSS DWI substudy, where 17% had new
20ischemic lesions. This is the rst time a new white lesion rate comparable to CEA has been
demonstrated by a stenting strategy, and it most likely results from the avoidance of
catheter/guidewire manipulation in the aortic arch.
Evolution of Embolic Protection Devices
Distal Devices—Occlusive
The rst carotid angioplasty and stenting procedure with embolic protection was performed by
Jacques Theron, using a homemade coaxial system that allowed temporary distal internal carotid
21artery occlusion during stent placement. This formed the basis of the subsequent PercuSurge
GuardWire (Medtronic).
Further examples of distal occlusive devices include the newer in-stent occlusion TwinOne system
(Minvasys, Gennevilliers, France) (Fig. e8-1), a variant of Theron's original concept, and the
FiberNet system (initially Lumen Biomedical, now Medtronic).
FIGURE E8-1 TwinOne System. (Courtesy Minvasys, Gennevilliers,
France.)
The TwinOne system limits cerebral protection to the poststenting angioplasty phase, one of the
22most emboligenic phases of the CAS procedure. The device has a compliant 0.014-inch
wiremounted balloon that is inFated within the leading cephalad end of the stent. The lesion is
predilated up to 2 mm if required, and a stent is placed, both stages being unprotected. The
TwinOne occlusion balloon is placed and, with a further angioplasty balloon, preloaded onto the
same wire. The TwinOne balloon is inFated, and gentle contrast injection is performed to ensure
adequate occlusion by the TwinOne balloon. The stent is balloon dilated with the second balloon.
Following dilation, there is gentle aspiration of the standing column via the guiding catheter, and
the TwinOne balloon is deflated and removed.
The FiberNet (Fig. e8-2) is a three-dimensional lter made up of hundreds of polyethylene
terephthalate (PET [Dacron]) bers delivered on a 0.014-inch guidewire. It features a low-crossing
pro le. A short landing zone is required, and the lter is designed to conform to asymmetric
vessels. The capture threshold is 40 microns, and the system requires aspiration of the standing
column prior to lter retrieval. This device therefore combines both tight ltration and a degree of
flow stagnation.
FIGURE E8-2 The FiberNet. (Courtesy Lumen Biomedical, Maple Grove,
Minn.)
Distal Devices—Filters
Filters became available around 1999. Newer lters, although based on the original lter design,
have been re ned over time with improvements in embolic capture and lower-pro le delivery
systems. The original lters were perforated polyurethane membrane types, with later devices
composed of nitinol mesh. Nitinol mesh allows better through-flow compared to polyurethane mesh,
with good Fow rates maintained despite up to 30 mg of captured emboli. This may, however, be at
the expense of lter through-Fow of emboli. Early examples of perforated polyurethane mesh lters
include NeuroShield (MedNova, Galway, Ireland), now Emboshield NAV6, (Abbott Vascular, Santa
Clara, Calif.), Angioguard (Cordis Corp., Bridgewater, N.J.), the FilterWire (Boston Scienti c,
Natick, Mass.), and the Accunet (previously Guidant Corp., now Abbott Vascular).
The newest of the lters is the Gore Embolic Filter (W.L. Gore & Associates, Flagsta , Ariz.) (Fig.
e8-3). This has a diamond frame designed to achieve superior wall apposition, thus reducing the
risk of debris passing between the frame and the vessel wall.

FIGURE E8-3 Gore Embolic Filter. (Courtesy W.L. Gore & Associates,
Flagstaff, Ariz.)
Proximal Embolic Protection Devices
Proximal EPDs have the advantage of e ecting “endovascular clamping” of the common carotid
artery (CCA) and ipsilateral external carotid artery (ECA). These devices cause either Fow arrest or
Fow reversal, thereby providing embolic protection before the lesion is crossed. This contrasts with
distal EPDs, where the initial lesion crossing is unprotected.
The prototype Fow reversal system was the Parodi Anti-Embolization Catheter (PAEC [ArteriA,
San Francisco, Calif.]). The PAEC guiding catheter had an occlusion balloon at the distal end of the
working sheath that was placed in the CCA via the common femoral artery. A further occlusion
balloon mounted on a 0.014-inch wire (a hypotube system) was placed in the ECA to eliminate
antegrade Fow in the ipsilateral ICA via retrograde Fow in the ipsilateral ECA, facilitated by the
circle of Willis. Occlusion of the ipsilateral CCA alone is ordinarily insu6 cient to e ect Fow
reversal in the ipsilateral ICA. The side port of the PAEC was then connected to a sheath in the
23femoral vein. The resultant arteriovenous (AV) shunt caused reversed Fow within the ICA. The
current Gore Flow Reversal system (Fig. e8-4) is an iteration of the PAEC.

FIGURE E8-4 Gore Flow Reversal System. (From Clair DG. Carotid stenting:
new devices on the horizon and beyond. Semin Vasc Surg 2008;21:88–94.)
The Mo.Ma device (initially Invatec [Roncadelle, Italy], now Medtronic) (Fig. e8-5) also employs
two compliant balloons to e ect Fow arrest; one is located on a “stalk” attached to the working
sheath and is inFated in the ECA to stop retrograde Fow. The other balloon is located toward the
end of the working sheath, and this is inFated in the CCA to stop antegrade CCA/ICA Fow. The
Mo.Ma has a working channel allowing access to the ICA when both balloons are inFated and Fow
arrest e ected. The “standing column” in the ICA is aspirated with three 20-mL syringes, and the
aspirate sieved until no debris is seen, before the balloons are deFated and antegrade ICA Fow is
established. Gentle Fow reversal occurs every time the rotating hemostatic valve on the working
sheath is opened.
FIGURE E8-5 Mo.Ma. (Courtesy Invatec, Roncadelle, Italy.)
The MICHI Neuroprotection System (Silk Road Medical, Sunnyvale, Calif.) (Fig. e8-6) results in
Fow reversal in both the ipsilateral ICA and ECA via direct CCA access through a 2- to 3-cm incision
just above the clavicle. Surgical control of the CCA is achieved before placement of the 10F (outer
diameter) sheath. The circuit is completed with femoral venous access and wide-bore low-resistance
tubing. The nature of this circuitry facilitates Fow reversal without occlusion of the ipsilateral ECA.
This procedure has been termed ow-altered short transcervical carotid artery stenting (FAST-CAS). The
technique results in easier lesion crossing, eliminating cannulation of arch vessels, and avoids ECA
manipulation as required by both the Mo.Ma and Gore Flow Reversal systems.
FIGURE E8-6 MICHI Neuroprotection System (Silk Road Medical Inc.,
Sunnyvale, Calif.)
Advantages and Disadvantages of Various EPD Strategies
Distal EPDs in the form of lters are intuitive in their function. They have the advantage of
allowing through-Fow when deployed, thus maintaining cerebral perfusion and allowing
angiography to be performed as required. However, there are unprotected stages of the procedure,
and a suitable landing zone is required. There are small but real risks of spasm and dissection of the
distal ICA. In addition, filters are imperfect in their control of the microembolic burden of CAS.
The major advantage of proximal EPDs is that protection is commenced before the lesion is
crossed. There are, however, disadvantages with proximal systems. Both the Mo.Ma and the Gore
Flow Reversal system have 9F working sheaths, generally requiring femoral rather than brachial or
radial access. This has implications in patients with CFA disease and unfavorable arch anatomy
(e.g. bovine/type III). Furthermore, signi cant stenosis or occlusion of the ipsilateral ECA renders
effective use of these systems challenging.
Additional problems can occur with patient intolerance to endovascular clamping. This
intolerance is poorly de ned but can result in reversible neurologic symptoms such as yawning,
drowsiness, obtundation, and seizure. It has been suggested that an intraprocedural systolic blood
pressure of 160 mmHg or more supports patient tolerance. Withholding the patient's
antihypertensive medication and administering intravenous hydration is usually su6 cient to attain
a satisfactory blood pressure. Vasopressor agents should be available during the procedure to
further enable blood pressure control.
There are a number of ways to manage “intolerance.” It should rst be recognized that the
majority of cases manifest intolerance (if at all) at two speci c time points: early in the procedure
or afterward. If intolerance occurs early in the procedure, “unclamping” the common carotid artery
and allowing antegrade Fow for a few minutes before reinFating the balloon in the common
carotid artery may su6 ce, through some poorly understood “conditioning” mechanism. Often one
will notice compensatory hypertension during “endovascular clamping” in tolerant patients. After
stent placement and/or post dilation, intolerance may manifest because the carotid baroreceptors
and compensatory mechanisms for blood pressure control have been overcome. At this point, the

procedure is close to completion, and it is appropriate to proceed in a timely fashion.
Alternatively, intermittent “clamping” can be employed or, once the lesion has been crossed on
Fow arrest/Fow reversal, the operator might wish to resort to distal lter protection. The MICHI
system, which e ects Fow reversal via direct CCA access through a mini cutdown, a ords
additional “bail out” options: the handheld Fow controller positioned between the arterial and
venous ends of the Fow reversal circuit provides high-Fow, low-Fow, and no-Fow settings, and one
can switch from high-Fow to low- or no-Fow modes to enhance tolerance. Lastly, since this system
is placed via a mini surgical cutdown, the operator may opt to convert to conventional CEA.
Patient intolerance, no matter how unpleasant to witness by the operating team, is better
tolerated by the patient than an embolic shower.
Clinical Data: Proximal Embolic Protection Devices
Mo.Ma
The ARMOUR (Proximal Protection with the Mo.Ma Device During Carotid Artery Stenting)
24registry recruited 262 patients who were considered to be high risk for CEA; 15.1% were
symptomatic, and 28.9% were octogenarians. Outcomes were independently reviewed and outcome
events independently adjudicated. The primary endpoint, 30-day all death/stroke/myocardial
infarction (DSMI), was 2.7%, with a major stroke rate of 0.9%. There were no strokes or deaths in
the symptomatic group, and the DSMI rate in octogenarians was 3.1%. The patient intolerance rate
in this study was reported to be 13.8%.
DESERVE was a single-arm prospective multicenter E.U. study that recruited 127 patients,
incorporating both standard and high-risk groups, with 12.6% of participants being symptomatic.
18The primary endpoint, 30-day DSMI, was 2.4%. Intolerance was reported in 11.8%.
Gore Flow Reversal System
The Embolic Protection with Flow Reversal (EMPiRE) study was a prospective multicenter study
comparing stroke, death, and myocardial infarction outcomes against an objective performance
25criterion (OPC) of 11.8% from previous distal EPD registries. This trial recruited 245 patients
who were considered high risk for CEA, with 32% being symptomatic and 16% being
octogenarians. The DSMI rate was 3.7%, increasing to 4.5% when transient ischemic attack (TIA)
was included, this being signi cantly less than the OPC of 11.8%. Intolerance was noted in 2.4%,
with flow reversal discontinued in half of these patients.
MICHI Neuroprotection System
PROOF was a German single-center study with 44 patients enrolled, with the primary endpoint
20being DSMI. Nine percent of patients were symptomatic. The DSMI rate was zero, with the
outcomes independently audited by a neuroanesthesiologist. One contralateral minor stroke at
30day review was independently judged to be unrelated to the procedure. Although intolerance to
flow reversal was reported in 9% (n = 4), all patients had a stent successfully placed.
A recent meta-analysis of 2397 CAS procedures performed with proximal embolic protection
revealed an all-stroke rate of 1.71%, a myocardial infarction rate of 0.02%, death rate of 0.4%,
and a 2.25% DSMI rate. These outcomes are signi cantly better than lter-protected series and
26randomized trials of largely filter-protected CAS versus CEA.
Clinical Data: Distal Embolic Protection Devices
Gore Filter
The Gore Embolic Filter in Carotid Stenting for High-Risk Surgical Subjects (EMBOLDEN)
multicenter study recruited 250 patients with a 30-day death/stroke/myocardial infarction rate of
4%, rising to 5.4% in both the octogenarian (n = 92) and symptomatic subgroups (n = 37). The
27EMBOLDEN trial is awaiting peer-reviewed publication.
FiberNet Embolic Protection System
28The FiberNet Embolic Protection System in Carotid Artery Stenting (EPIC) Trial recruited 237
patients considered to be at high risk for CEA; 20% were symptomatic and 21% were
octogenarians. The primary endpoint was 30-day DSMI, this rate being 3%. The event rate was
higher in the symptomatic patient subset (4.2%) and in octogenarians (8.2%). Visible debris was
aspirated in 90.9% of cases. This is a higher yield than with other devices; for example, the SpideRX
nitinol mesh lter, evaluated in the Carotid Revascularization with ev3 Arterial Technology
29Evolution (CREATE) trial was reported as yielding visible debris in 36%. The FiberNet high yield
was attributed to the tighter ltration characteristics of the device and the aspiration stage, which
may have promoted fragmentation of particles, resulting in many more smaller-particle fragments
than if this stage were not integral to the protective mechanism.
TwinOne
The TwinOne was evaluated in a French multicenter study comprising 217 stenting procedures in
209 patients. The primary endpoint was all death/stroke/TIA. A total of 32.5% were symptomatic;
the primary endpoint occurred in 2.76% (1.8% disabling stroke and 0.92% TIA), with no signi cant
di erence between symptomatic and asymptomatic groups. Predilation of the lesion was performed
in 10%, with no intolerance to balloon occlusion of the ICA reported. The authors chose longer
stents than are conventionally chosen for CAS (i.e., 5-cm and 6-cm lengths). The stents extended
into the ICA covering the ECA origin for this study, with the rationale of stenting from healthy CCA
to healthy ICA and to better correct for tortuous vessels. The TwinOne balloon inFation within the
30stent reduces spasm of the ICA, as can occur with other distal EPDs.
Embolic Protection Devices in Noncarotid Circulation
Renal Circulation
Some operators advocate the use of EPDs during renal stenting, but a recent trial demonstrated
31no bene t in the glomerular ltration rate with EPD use during renal stenting. Cholesterol
emboli, which are needle-shaped entities of around 1 micron in diameter, may be generated by
renal stenting, yet would evade capture by most of the currently available lter-type devices. At
present, there are no dedicated EPDs for the renal circulation, and further formal evaluation is
required before their use can be recommended routinely.
Peripheral Circulation (Atherectomy)
Macroembolization during atherectomy is very common. The Protected Carotid Artery Stenting in
Patients at High Risk for Carotid Endarterectomy (PROTECT) single-center study sought to evaluate
embolic protection with the SpiderFX (ev3/Covidien, Plymouth, Minn.) or Emboshield lters in the
32peripheral lower limb circulation. The lters captured debris in all patients when the SilverHawk
atherectomy device (ev3/Covidien) was used, with emboli greater than 2 mm present in 90.9% of
examined filters.
Coronary Circulation
A full discussion of EPDs is beyond the scope of this chapter. However, the Saphenous Vein Graft
Angioplasty Free of Emboli Randomized (SAFER) Trial demonstrated a signi cant reduction of
major adverse events arising from embolization during percutaneous intervention of saphenous
33vein aortocoronary bypass grafts when the PercuSurge GuardWire was used.
Conclusions
Data supporting embolic protection during endovascular procedures in the peripheral and renal
territories are limited. Protected CAS is associated with better stroke and death outcomes than
unprotected CAS. Proximal EPDs e ect better control of the microembolic burden of CAS than distal
lters, and a recent meta-analyses of CAS outcomes with proximal protection demonstrates stroke
and death outcomes that are substantially better than those series and trials in which lters were
employed. Some of these improvements may be due to a better understanding of patient and lesion
selection (intimately related to operator experience), but the inFuence of improved protection
strategies on outcome cannot be overlooked.
Key Points
• Protected carotid artery stenting (CAS) is associated with better stroke and death
outcomes than unprotected CAS.
• Embolic protection devices employ one or more of the following strategies:
• Vessel filtration
• Vessel occlusion (distal)
• Vessel occlusion (proximal) with:
• Flow arrest
• Flow reversal
• Operator experience plays a significant role in reducing adverse events.
• Catheterization of the arch and great vessels may be associated with significant risk for
embolic events.
▸ Suggested Readings
Altinbas, A, van Zandvoort, MJ, van den Berg, E, et al. Cognition after carotid endarterectomy or
stenting: a randomised comparison. Neurology. 2011; 77:1084–1090.
Ansel, GM, Hopkins, NL, Jaff, MR, et al. Safety and effectiveness of the Invatec Mo.Ma proximal
cerebral protection device during carotid artery stenting. Results from the ARMOUR pivotal
trial. Catheter Cardiovasc Interv. 2010; 76:1–8.
Bersin, RM, Stabile, E, Ansel, G, et al. A meta-analysis of proximal occlusion device outcomes in
carotid artery stenting. Catheter Cardiovasc Interv. 2012.
Bijuklic, K, Wandler, A, Hazizi, F, Schofer, J. The PROFI Study (Prevention of Cerebral
Embolization by Proximal Balloon Occlusion Compared to Filter Protection During Carotid
Artery Stenting) a prospective randomized trial. J Am Coll Cardiol. 2012.
Bonati, LH, Jongen, LM, Haller, S, et al. New ischaemic brain lesions on MRI after stenting or
endarterectomy for symptomatic carotid stenosis: a substudy of the International Carotid
Stenting Study (ICSS). Lancet Neurol. 2010; 9(4):353–362.
Clair, DG, Hopkins, LN, Metha, M, et al. Neuroprotection during carotid artery stenting using theGORE Flow Reversal System: 30-day outcomes in the EMPiRE clinical study. Catheter Cardiovasc
Interv. 2011; 77:420–429.
Gore industry
data.
http://www.goremedical.com/resources/dam/assets/AP4545EN1EmboldenStudyResults%20PPTFNL%20MR.pdf.
Gupta, N, Corriere, MA, Dodson, TF, et al. The incidence of microemboli to the brain is less with
endarterectomy than with percutaneous revascularization with distal filters or flow reversal. J
Vasc Surg. 2011; 53:316–322.
Montorsi, P, Caputi, L, Galli, S, et al. Microembolization during carotid artery stenting in patients
with high-risk, lipid-rich plaque. A randomized trial of proximal versus distal cerebral protection.
J Am Coll Cardiol. 2011; 58(16):1656–1663.
Myla, S, Bacharach, M, Ansel, GM, et al. Carotid artery stenting in high surgical risk patients using
the FiberNet(r) Embolic Protection System: The EPIC Trial results. Catheter Cardiovasc Interv.
2010; 75:817–822.
Pinter, L, Ribo, M, Loh, C, et al. Safety and feasibility of a novel transcervical access
neuroprotection system for carotid artery stenting in the PROOF study. J Vasc Surg. 2011;
54(5):1317–1323.
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