By James Wey, Christopher Chan, Elizabeth Quadros, Ziad Sergie,Jason Sousa, Lillian Hang
In the past 30 years, the incidence of AAA has tripled in the Western world and is the 13th leading cause of death in the US. • There are approximately 200,000 patients diagnosed with AAA in the US each year, and approximately 500,000 patients diagnosed worldwide. Estimated AAA Diagnosed each year. Adapted from Lester et. al • An estimated 60% of patients diagnosed with AAA are considered suitable for the new endovascular repair method.
Stent-Graft vs. Conventional Surgery • The approximate cost for conventional open-chest surgery is approximately $31,000. • There are approximately 110,000 conventional surgeries performed in 2001 worldwide, which amounts to an expenditure of about $3.41 billion. • Average ICU stay is about 55 hours. • The stent-grafts costs $12,000, and the entire operation is approximately $27,000. • There are approximately 85,000 stent- graft procedures performed in 2001 worldwide, which amounts to a cost of $2.3 billion. • Average ICU stay is close to none.
Diagnosis and Risk Factors • Diagnostic techniques: • Abdominal X-ray • CT (Computed Tomography) • MRI (Magnetic Resonance Imaging) • Arteriogram • Risk Factors • Family History • Increased age (over 60) • Male gender • Smoking • High blood pressure • High cholesterol • Atherosclerosis • Cardiovascular Disease • Obesity Source:http://www.aorticaneurysm.com April 26, 2002
Treatment • Do nothing except monitor the status of the aneurysm with routine ultrasounds. This option is preferred if the AAA is relatively small (4-6cm) and the patient is elderly or very high risk. • Conventional surgery- Common choice of treatment for large aneurysms in otherwise young and healthy patients. • Endoluminal surgery with stented graft- this usually represents the best choice for an elderly or high risk patient with an aneurysm that must be repaired. Source:http://www.aorticaneurysm.com April 26, 2002 Source:http://www.aorticaneurysm.com April 26, 2002
Risks Associated with Treatment • On the Operating Table • failure to complete the procedure • device-related or procedure-related complications • and arterial complications • Usually up to 30 Days Post-Operation • graft-limb thrombosis or kinking • peripheral embolization • local hematoma or bleeding • failure to advance the device into the correct position • vascular laceration • occlusion of the renal arteries • device migration • systemic complications related to organ failure • paraplegia • infection of insertion site • endoleak (most common)
Risks Associated with Treatment (continued) • Usually after 30 Days Post-Operation • peripheral vascular occlusion • device disruption or dislodgement • aneurysm rupture • Problems Discovered Upon Recovery of the Stent • Stents without barbs or hooks detached readily from the native arteries • Very little or no vascular tissue at all was found adhered to the fabrics • constant endoleak and graft-migration • Major Causes of Death • anatomically incompatible device • migrated stent causing the occlusion of renal arteries • thrombosis • post-operative renal failure(7% of stent-graft procedure)
Companies and the Devices • FDA Approved • Guidant - Ancure • Medtronic - AneuRX • In Clinical Trials • Boston Scientific - Vanguard III • Cook Group - Zenith • Edwards Lifesciences - Lifepath • Endologix - PowerLink • W.L. Gore and Assoc. - Hemobahn; Excluder • Sulzer Vascutek - Anaconda • TeraMed - Ariba • World Medical - TalentManufacturing/Medtronic
Guidant • Ancure • Uses hooks to secure the graph in place • 8,000 sold in 2001 • Made of Dacron and Elgiloy • Recalled recently because the hooks damaged arterial walls Source:http://www.medicaldata.com April 26, 2002
Medtronic • AneuRX • Uses a pressure fit to secure the graft in place • Made of Dacron and Nitinol • Modular device • 30,000 sold in 2001 • growth of sales is 80% per year • More popular device than Guidant’s Ancure Source:http://www.medicaldata.com April 26, 2002
Future of the Endoluminal Stents • Rapamycin coated stents • Implant Sciences • Gold-coated Nitinol Stent • CardioTech • ChronoFlex • Use for Thoratic Aortic Aneurysms • Non-Stented Grafts • Surgical Assisted Therapies • Use laproscopic techniques to secure the graft Source:J Thorac Cardiovasc Surg 2001; 122:47-52 Source:http://www.ideasforsurgery.com/SAT_solutions3.htmlApril 26, 2002