Risk-Adjusted Meta-analysis of 30-Day Mortality of Endovascular Versus Open Repair for Ruptured Abdominal Aortic Aneurysms

Abstract

In recent years, the relative benefits of endovascular repair (EVAR) in the treatment of ruptured abdominal aortic aneurysms (rAAAs) compared with those of open repair have been postulated. However, sufficient quantification and evidence-based validation of the role of EVAR in the care pathway for these patients is still lacking. The aim of the present meta-analysis was to investigate the impact of hemodynamic instability and other potential risk factors on 30-day mortality of EVAR versus open repair for rAAAs by performing a meta-regression analysis of previously published data. Studies comparing perioperative outcomes of endovascular and open repair of ruptured infrarenal or juxtarenal abdominal aortic aneurysm were considered for analysis. All types of comparative studies, including prospective or retrospective, observational studies, or randomized controlled trials (RCTs), were included. Meta-analysis was undertaken using the Mantel-Haenszel method, with a standard continuity correction of 0.5. A random-effects model was used owing to the variability in baseline characteristics in each article. Furthermore, an odds ratio (OR) for 30-day mortality adjusted for patients' hemodynamic condition at presentation in the hospital was calculated by performing a meta-regression analysis. The entire meta-analysis population comprised 81,681 patients (63 studies), of whom 13,706 underwent EVAR and the remaining 67,975 had an open repair of their rAAA. Without correction for hemodynamic instability, patients undergoing EVAR had a significantly lower 30-day mortality rate than patients having open repair (OR, 0.512; 95% confidence interval [CI], 0.457-0.574; P < 0.01). Moderate heterogeneity among the studies was identified(I(2) = 53.303%), and the likelihood of publication bias was low (P = 0.183). In the RCTs alone (3 studies), patients undergoing EVAR had no significantly lower 30-day mortality rate than patients with open repair (OR, 0.930; 95% CI, 0.691-1.253; P < 0.633). In all studies available, after adjustment for patients' hemodynamic condition at presentation to the hospital, the OR for 30-day mortality was 0.872 (95% CI, 0.598-1.270; P = 0.474), as well, indicating no significant difference between the 2 therapeutic options. Because a hemodynamically unstable condition may result in poorer clinical outcome, we calculated the 30-day mortality OR adjusted for patients' hemodynamic condition. After adjustment, there was no benefit in 30-day mortality for EVAR compared with that in open surgery.