Center volume and failure to rescue after open or endovascular repair of ruptured abdominal aortic aneurysms

Background: The correlation between center volume and elective abdominal aortic aneurysm (AAA) repair outcomes is well established; however, these effects for either endovascular aneurysm repair (EVAR) or open aneurysm repair (OAR) of ruptured AAA (rAAA) remains unclear. Notably, the capacity to either avert or manage complications associated with postoperative mortality is an important cause of outcome disparities after elective procedures; however, there is a paucity of data surrounding nonelective presentations. Therefore, the purpose of this analysis was to describe the association between annual center volume, complications, and failure to rescue (FtR) after EVAR and OAR of rAAA. Methods: All consecutive endovascular and open rAAA repairs from 2010 to 2020 in the Vascular Quality Initiative were examined. Annual center volume (procedures/year per center) was grouped into quartiles: EVAR-Q1 (<14), 3.4%; Q2 (14-23), 12.8%; Q3 (24-37), 24.7%; and Q4 (>38), 59.1%; OAR-Q1 (<3), 5.4%; Q2 (4-6), 12.8%; Q3 (7-10), 22.7%; and Q4 (>10), 59.1%. The primary end point was FtR, defined as in-hospital death after experiencing one of six major complications (cardiac, renal, respiratory, stroke, bleeding, colonic ischemia). Risk-adjusted analyses for intergroup comparisons were completed using multivariable logistic regression. Results: The unadjusted in-hospital death rate was 16.5% and 28.9% for EVAR and OAR, respectively. Complications occurred in 45% of EVAR (n = 1439/3188) and 70% of OAR (n = 1366/1961) patients with corresponding FtR rates of 14% (EVAR) and 26% (OAR). For OAR, Q4-centers had a 43% lower FtR risk (odds ratio [OR], 0.57; 95% confidence interval [CI], 0.4-0.9; P = .017) compared with Q1 centers. Centers performing fewer than five OARs/year had a 43% lower risk (OR, 0.57; 95% CI, 0.4-0.7; P < .001) of FtR and this decreased 4% for each additional five procedures performed annually (95% CI, 0.93-0.991; P = .013). However, there was no significant relationship between center volume and FtR after EVAR. The risk of FtR was strongly associated with a greater number of complications for both procedures (OR multiplied by 6.5 for EVAR and 1.5 for OAR for each additional complication; P < .0001). Among OAR patients with a single recorded complication, return to the operating room for bleeding had highest risk of in-hospital mortality (OR, 4.1; 95% CI, 1.1-4.8; P = .034), whereas no specific type of complication increased FtR risk after EVAR. Conclusions: FtR occurs commonly after EVAR and OAR of rAAA within Vascular Quality Initiative centers. Importantly, increasing center volume was associated with decreased FtR risk after OAR, but not EVAR. Complication pattern and frequency predicted FtR after either repair strategy. For stable patients, especially those deemed anatomically ineligible for EVAR, these findings emphasize the need to improve the coordination of regional referral networks that centralize rAAAs to high-volume centers. Moreover, hospitals that treat rAAA should invest in resources that develop protocols targeting specific complications to mitigate risk of preventable postoperative death.