A multi-center, randomized clinical trial that will compare endovascular repair with standard open surgery in the repair of abdominal aortic aneurysms (AAA). Long and short-term results as well as the cost and quality of life associated with these two strategies for AAA repair will be compared.

Primary Hypothesis: All-cause mortality will differ by 25% between Endovascular repair (EVR) and Open surgery. Secondary Hypotheses: Procedure failure, short term (12 month) major morbidity, number of hospital days, health-related quality of life and other procedure-related abnormalities will differ between the two AAA repair strategies. Primary Outcomes: All-cause mortality. Interventions: Patients will be randomized to one of these repair strategies for the elective treatment of AAA: (a) Open surgery or (b) Endovascular repair (using FDA-approved devices). Study Abstract: Aortic aneurysm is the tenth leading cause of death in older men; AAA accounts for the majority of these deaths (about 10,000 deaths per year in the United States). Since one in 22 veterans over the age of 50 have AAA and one in 200 have AAA with diameter greater or equal to 5.0 cm (making them candidates for elective repair), AAA is a major disease in the VA population. Recently, the FDA has approved two EVR systems for AAA; however, questions about their relative safety and effectiveness have been raised and remain unanswered. To answer these questions, this multi-center, randomized clinical trial comparing EVR with standard open surgery is proposed. Patients for whom elective repair of AAA is indicated and who are suitable candidates for both open repair and EVR will be eligible for the study. The anticipated duration of the study is 9 years with a proposed sample size of 900 patients. The first planning meeting took place on March 9-10, 2000 and the second planning meeting took place on November 6-7, 2000. The OVER protocol was submitted and reviewed by CSEC on May 10, 2001 and approved. The kickoff was June 12, 2002. First annual meeting was held September 30, 2003; first DSMB meeting took place September 29, 2003. Second DSMB meeting held on April 19, 2004; second annual meeting was held on June 29, 2004. Third DSMB meeting was held on December 6, 2004; third annual meeting was held on March 15, 2005. The fourth DSMB meeting was held on July 19, 2005 and the fourth annual meeting was held March 21, 2006. The fifth DSMB meeting was held on March 6, 2006. The sixth DSMB meeting was held on November 6, 2006. The seventh DSMB meeting was held on May 14, 2007 and the fifth annual meeting was held on June 6, 2007. The eighth DSMB meeting was held on April 7, 2008.

• Active Comparator: Standard Open Repair
• Active Comparator: Endovascular Repair

Inclusion Criteria:

• AAA with a maximum external diameter in any plane greater than or equal to 5 cm.
• An iliac aneurysm (associated with an AAA) with a maximum external diameter in any plane greater than or equal to 3 cm.
• AAA greater than or equal to 4.5 cm and the AAA has increased by greater than or equal to 0.7 cm in diameter in 6 months.
• An AAA greater than or equal to 4.5 cm and the AAA has increased by greater than or equal to 1 cm in diameter in 12 months.
• An AAA greater than or equal to 4.5 cm and the AAA is saccular (i.e., a portion of the circumference of the aorta at the level of the aneurysm is considered normal based on CT scan or MRI).

• An AAA greater than or equal to 4.5 cm and the AAA is associated with distal embolism.

  • as measured from two imaging studies (ultrasound CT scan or MRI) within the appropriate interval, the later one within 6 months of randomization.

Exclusion Criteria:

• Patient has had a previous AAA repair procedure
• Evidence of AAA rupture by imaging test
• AAA is not elective (i.e., urgent or emergent operation, usually due to suspected rupture)
• Likelihood of poor compliance to the protocol
• Patient refused randomization
• Physician refused randomization