Digital CT showing endovascular stenting of an abdominal aortic aneurysm with bilateral iliac aneurysms, using a technique that preserves flow into both internal iliac arteries (purple arrows) Source: The Cleveland Clinic

Among older patients with isolated intact abdominal aortic aneurysm (AAA), the use of open repair compared with endovascular repair was associated with increased risk of all-cause mortality and AAA-related mortality, based on a large retrospective analysis of Medicare data published April 18 in the Journal of the American Medical Association.

Endovascular repair of AAA, which was initially introduced as an option for high-risk patients, has surpassed open surgery as the most common technique for elective management of AAA among Medicare beneficiaries in the U.S., according to the study authors. They also noted that randomized controlled trials “have failed to demonstrate a long-term survival advantage of endovascular compared with open repair. Furthermore, compared with open repair, endovascular repair incurs higher costs and a need for long-term surveillance because of a 25 percent to 40 percent late complication rate, leading to ongoing controversy over the elective use of endovascular repair, especially in healthy patients with anticipated long-term survival.”

Thus, in this study, Rubie Sue Jackson, MD, MPH, of the department of surgery at Georgetown University Hospital in Washington, D.C., and colleagues sought to compare long-term outcomes after open vs. endovascular repair of AAA through a retrospective analysis of patients 65 years or older in the Medicare Standard Analytic File, 2003-2007, who underwent isolated repair of intact AAA. The cause of death was determined from the National Death Index.

The researchers defined the primary outcome as all-cause mortality, and the secondary outcomes as AAA-related mortality, hospital length of stay, one-year readmission, repeat AAA repair, incisional hernia repair and lower extremity amputation.

Of 4,529 included patients, 703 were classified as having undergone open repair and 3,826 as having undergone endovascular repair. Mean and median follow-up times were 2.6 and 2.5 years, respectively.

In an unadjusted analysis, Jackson et al found that both all-cause mortality (173 vs. 752; 89 vs. 76/1,000 person-years) and AAA-specific mortality (22 vs. 28; 11.3 vs. 2.8/1,000 person-years) were higher after open vs. endovascular repair. After adjusting for emergency admission, age, calendar year, sex, race and comorbidities, there was a higher risk of both all-cause mortality and AAA-related mortality after open vs. endovascular repair.

The adjusted hospital length of stay was, on average, 6.5 days longer after open repair (mean, 10.4 days), compared with endovascular repair (mean, 3.6 days), the study authors reported. Incidence of incisional hernia repair was higher after open AAA repair (19 vs. 23; 12 vs. three per 1,000 person-years), whereas the incidence of one-year readmission (188 vs. 1,070; 274 vs. 376/1,000 person-years), repeat AAA repair (15 vs. 93; 9.7 vs. 12.3/1,000 person-years) and lower extremity amputation (three vs. 25; 1.9 vs. 3.3/1,000 person-years) did not differ by repair type.

They acknowledged that previous studies have raised concerns about the possible need for more reinterventions after endovascular AAA repair compared with open repair, but in this study, there was no evidence of a difference in hazard of one-year readmission, repeat AAA repair or lower extremity amputation between the two repair types.

“We have demonstrated that, after adjusting for demographics and comorbidities, endovascular AAA repair was associated with a long-term survival advantage when compared with open repair in patients 65 years or older,” Jackson et al concluded. “This survival difference was related to higher mortality within the first month after open repair but persisted for the entire five-year follow-up period.

"We demonstrated a longer average hospital stay after open AAA repair and a higher risk for repair of incisional hernia after open AAA repair but did not find evidence of differences in the hazard of rehospitalization within one year after AAA repair, repeat repair or lower extremity amputation, comparing open vs. endovascular repair.”