Outcomes after ruptured abdominal aortic aneurysm repair in the era of centralized care

Objective: Little is known about the relationship between case volume and patient outcomes of those treated for ruptured abdominal aortic aneurysm (rAAA) after either endovascular aneurysm repair (EVAR) or open aneurysm repair (OAR). This study evaluated the impact of hospital case volume on outcomes after rAAA.

Methods: Patients with rAAA were identified in the Society for Vascular Surgery Vascular Quality Initiative database from 2003 to 2017, excluding patients from years in which a limited number of hospitals were included (2003-2009, 2017). Patients were stratified according to type of aneurysm repair and further stratified according to aortic surgical volume of the treating facility. Univariate and multivariable analyses were performed.

Results: Between 2010 and 2016, of 2895 patients who presented emergently with rAAA, 1246 underwent ruptured OAR (rOAR) and 1649 underwent ruptured EVAR (rEVAR). Before adjustment for demographics, comorbidities, and clinical characteristics, there were no differences in 1-year patient survival based on hospital OAR or EVAR volumes among patients undergoing rOAR or rEVAR. After adjustment for confounding variables, patients treated with rOAR at the highest volume OAR hospitals had a 33% lower hazard of mortality at 1 year relative to patients treated with rOAR at the lowest volume OAR hospitals. Preoperative interfacility transfer was associated with a 27% lower hazard of mortality after rOAR. There was no significant difference in hazard of mortality among patients undergoing rEVAR when they were stratified according to hospital EVAR volumes after adjustment for all other covariates.

Conclusions: Outcomes after rAAA repair are associated with hospital volume among patients undergoing rOAR but not among patients undergoing rEVAR. Thus, centralization of care may have an important impact on outcomes when OAR is indicated, suggesting a benefit for preoperative interfacility transfer of care when it is feasible.