Authors' objectives:

The aim of this review was to evaluate: - treatment options for nonruptured abdominal aortic aneurysms (AAA) - the relationship of hospital and physician volume to outcomes for endovascular repair (EVAR) - affect of patient and AAA factors on outcomes - cost-benefits of treatments

Authors' results and conclusions: Initial or attained diameter is the strongest known predictor of rupture. The annual risk of rupture is below 1 percent for AAA <5.5 cm in diameter. Among medically ill patients unfit for open-surgical repair (OSR) with AAA > or =5.5 cm, the risk of rupture may be as high as 10 percent per year. Early/immediate OSR of AAA <5.5 cm (two trials n=2,226) did not reduce all-cause mortality compared with surveillance and delayed OSR. Results did not differ according to age, gender, baseline AAA diameter, or creatinine concentration. Two RCT with followup of at least 2 years compared EVAR to OSR for AAA > or =5.5 cm. EVAR reduced postoperative 30-day mortality compared to OSR (1.6 percent EVAR vs. 4.7 percent OSR, RR = 0.34 [0.17 to 0.65]). Early reduction in all-cause mortality with EVAR disappeared before 2 years. Post-operative complications and reinterventions were higher with EVAR. Quality of life differences were small and disappeared after 3-6 months. One RCT of patients with AAA > or =5.5 cm judged medically unfit for OSR (n=338), reported no difference in all-cause mortality or AAA mortality between EVAR and no intervention (HR = 1.21; 95 percent CI 0.87 to 1.69). Forty-eight nonrandomized reports evaluated EVAR. Patient, AAA characteristics, and outcomes were similar to RCT comparing EVAR to OSR. A volume outcome relationship has been shown for OSR, but there are no data adequate to estimate the effect of hospital or physician volume on EVAR outcomes or to identify a volume threshold for policymakers. Immediate OSR for AAA <5.5 cm costs more and does not improve long-term survival compared to active surveillance and delayed OSR. The cost effectiveness of EVAR relative to OSR is difficult to determine. However, compared to OSR for AAA > or =5.5 cm, EVAR has greater in-hospital costs primarily due to the cost of the prosthesis. EVAR has shorter length of stay, lower 30-day morbidity and mortality but does not improve quality of life beyond 3 months or survival beyond 2 years, and is associated with complications, need for reintervention, long-term monitoring, and higher longterm costs. Compared to no intervention in patients medically unfit for OSR, EVAR costs more and does not improve survival or quality of life.

Authors' recommendations: For AAA <5.5 cm in diameter, active surveillance with delayed OSR results in equivalent mortality but lesser morbidity and operative costs due to fewer interventions compared to immediate OSR. For AAA > or =5.5 cm, EVAR has not been shown to improve longterm survival or health status over OSR though peri-operative outcomes are improved. EVAR does not improve survival in patients who are medically unfit for OSR. EVAR is associated with more complications, need for reintervention, monitoring, and costs compared to OSR or no intervention. U.S. RCT are needed using approved EVAR devices to evaluate patient outcomes.

Authors' methods: Systematic review

Project Status: Completed

URL for project: http://www.ahrq.gov/clinic/tp/aaareptp.htm

Year Published: 2006

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: Agency for Healthcare Research and Quality

Contact Address: Center for Outcomes and Evidence Technology Assessment Program, 540 Gaither Road, Rockville, MD 20850, USA. Tel: +1 301 427 1610; Fax: +1 301 427 1639;

Contact Name: martin.erlichman@ahrq.hhs.gov

Contact Email: martin.erlichman@ahrq.hhs.gov

Copyright: Agency for Healthcare Research and Quality (AHRQ)