The outcome of endovascular repair of small abdominal aortic aneurysms

Objective: To assess the outcome of endovascular repair (EVAR) of small abdominal aortic aneurysms (AAA, <= 5.5 min maximum diameter) in Australia. Summary Background Data: Randomized trials have suggested that small AAAs should not be treated by open surgery. EVAR is associated with less perioperative mortality than open surgery for large AAAs. We assessed the outcome of EVAR of small AAAs as part of a national audit. Methods: ASERNIP-S carried out a prospective audit of EVAR performed between November 1999 and May 2001 in Australia. A total of 478 of the 961 patients entered underwent treatment of a small AAA. Data were collected regarding preoperative characteristics, procedural outcome, and intermediate success. Median follow-up was 3.2 years. Data were analyzed using Kaplan-Meier and Cox proportional hazard analyses. Results: The 30-day mortality and technical success rates were 1.1% and 98%, respectively. Postoperative complications occurred in 29%. Survival was 84% and 52% at 3 and 5 years, respectively. Primary, assisted primary, and secondary clinical success rates were 72%, 79%, and 82%, respectively, at 3 years. Reintervention rate was 11% at 3 years; however, 15% of patients continued to have significant aortic sac enlargement. Survival was reduced in patients considered unfit for general anesthesia (odds ratio = 2.6; 95% confidence interval, 1.4-4.8 P = 0.002) or those who had elevated preoperative serum creatinine (odds ratio = 2.0; 95% confidence interval, 1.3-3.0, P = 0.001). Conclusions: EVAR can be carried with good perioperative outcome in patients with small AAA; however, intermediate success is hampered by the need for reintervention and continued aortic sac enlargement. At present, widespread treatment of small AAAs by EVAR would appear inappropriate.