Endovascular treatment of ruptured abdominal aortic aneurysms in the United States (2001-2006): a significant survival benefit over open repair is independently associated with increased institutional volume

Abstract

Objective: Endovascular aortic repair (EVAR) has gained wide acceptance for the elective treatment of abdominal aortic aneurysms (AAA), leading to interest in similar treatment of ruptured abdominal aortic aneurysms (RAAA). The purpose of this study was to evaluate national outcomes after EVAR for RAAA and to assess the effect of institutional volume metrics.

Methods: The Nationwide Inpatient Sample was used to identify patients treated with open or EVAR for RAAA, 2001-2006. Procedure volume was determined for each institution categorizing hospitals as low-, medium-, and high-volume. The primary outcome was in-hospital mortality. Secondary outcomes related to resource utilization. Multivariable logistic regression models were used to determine independent predictors of EVAR usage and mortality.

Results: From 2001 to 2006, an estimated 27,750 hospital discharges for RAAA occurred; 11.5% were treated with EVAR. EVAR utilization increased over time (5.9% in 2001 to 18.9% in 2006, P < .0001) while overall RAAA rates remained constant. EVAR had a lower overall in-hospital mortality than open repair (31.7% vs 40.7%, P < .0001), an effect which amplified when stratified by institutional volume. On multivariable regression, open repair independently predicted mortality (odds ratio [OR] 1.56; 95% confidence interval [CI] 1.29-1.89). EVAR usage for RAAA increased with age (>80 years) (OR 1.58; 95% CI 1.30-1.93), high elective EVAR volume (>40/y) vs medium (19-40/y) (OR 2.65; 95% CI 1.86-3.78) and low (<19/y) (OR 5.37; 95% CI 3.60-8.0). EVAR had a shorter length of stay (11.1 vs 13.8 days, P < .0001), higher discharges to home (65.1% vs 53.9%, P < .0001), and lower charges ($108,672 vs $114,784, P < .0001).

Conclusions: In the United States, for RAAA, EVAR had a lower postoperative mortality than open repair. Higher elective open repair as well as RAAA volume increased this mortality advantage for EVAR. These results support regionalization of RAAA repair to high volume centers whenever possible and a wider adoption of endovascular repair of RAAA nationwide.