Comparison of Long-term Survival After Open vs Endovascular Repair of Intact Abdominal Aortic Aneurysm Among Medicare Beneficiaries

Abstract

Conclusion: In Medicare beneficiaries, repair of isolated, intact abdominal aortic aneurysms (AAA) by endovascular means is associated with a lower risk of all-cause mortality and AAA-related mortality than repair using open techniques. Summary: Randomized clinical trials (RCTs) have failed to demonstrate a long-term survival advantage of endovascular repair vs open repair of AAA. Furthermore, a previous study of Medicare beneficiaries undergoing AAA repair between 2001 and 2004 also failed to demonstrate a survival advantage of endovascular repair over open repair beyond 3 years of follow-up (Schemerhorn ML et al, N Engl J Med 2008;358:464-74). It is possible current endovascular devices may provide improved overall results of endovascular repair than those available for analysis of endovascular vs open AAA repair in the previous study of Medicare beneficiaries. The authors, therefore, decided to compare overall and AAA-specific mortality, readmission, and reintervention after endovascular vs open repair of nonruptured AAAs in Medicare beneficiary patients using a database from 2003 to 2007. This was a retrospective analysis of patients aged ≥65 years in the Medicare standard analytic file, 2003 to 2007, who underwent isolated repair of an intact AAA. The national death index was used to determine cause of death. Primary outcome was all-cause mortality. Secondary outcomes were AAA-related mortality, hospital length of stay, 1-year readmission, repeat AAA repair, incisional hernia repair, and lower extremity amputation. The Medicare standard analytic files contained data from a 5% example of Medicare inpatient discharges. The study included 4029 patients; of these, 703 underwent open repair and 3826 underwent endovascular repair. Mean and median follow-up times were 2.6 (SD, 1.5) and 2.5 (interquartile range, 2.4) years, respectively. After adjusting for emergency admission, age, calendar year, sex, race, and comorbidities, there was a higher risk of both all-cause mortality (hazard ratio, 1.24; 95% confidence interval [CI], 1.05-1.47; P = .01) and AAA-related mortality after open vs endovascular repair (hazard ratio, 4.37l; 95% CI, 2.51-7.66; P < .001). Adjusted hospital length of stay averaged 6.5 days (95% CI, 6.0-7.0 days; P < .001) longer after open repair (mean, 10.4 days) compared with endovascular repair (mean, 3.6 days). Need for incisional hernia repair was higher after open AAA (P < .001). The 1-year readmission rates, repeat AAA repair, and lower extremity amputation did not differ by repair type. Comment: The data presented here do not demonstrate inferiority of endovascular vs open AAA repair. However, there are really too many deficiencies in the data to justify a conclusion that the data demonstrate superiority of endovascular vs open repair of AAAs. First, follow-up is relatively short and the number of patients analyzed quite small compared with the number potentially available for analysis. In addition, the Medicare database does not contain information about aneurysm configuration and other anatomic factors that may influence surgeon choice of endovascular or open repair. Given the general acceptance of endovascular repair, it is quite likely many—if not most—of the patients undergoing open repair were judged not suitable for endovascular repair. The report compares survival after open or endovascular repair but not necessarily in patients suitable for either open or endovascular repair. The report does not adequately address reinterventions. Most patients undergo reinterventions for failure of endovascular repair as outpatients, which was not analyzed in this study, and reinterventions for open and endovascular aneurysm graft-related failure requiring readmission tend to occur beyond the median follow-up of this report (Kelso RL et al, J Vasc Surg 2009;49:589-95; and Brinster CJ et al, J Vasc Surg 2011;54:42-6). The most reasonable conclusion provided by the data is that endovascular repair as a form of management of AAA is a reasonable approach for management of anatomically suitable patients with AAA who are Medicare beneficiaries. The data are not suitable for cost-analysis or analysis of all relevant reinterventions.