Higher Hospital Volume of All Non-cardiac Open Aortic Procedures is Associated with Lower In Hospital Mortality after Open Infrarenal Aortic Aneurysm Repair: Secondary Data Analysis of German Hospital Episode Statistics from 2010 to 2023.

Abstract

Although endovascular techniques dominate the treatment of abdominal aortic aneurysms (AAAs), open aortic repair (OAR) remains essential for selected patients. As previous research has focused primarily on procedure specific hospital volume for infrarenal AAA repair, this study evaluated whether hospital volume of cumulated non-cardiac open aortic procedures is associated with in hospital death and peri-operative outcomes after infrarenal OAR for intact AAA (iAAA). This study was a retrospective nationwide secondary data analysis based on German hospital episode statistics (diagnosis related group [DRG] data) covering the years 2010 to 2023. All hospitals performing non-cardiac open aortic procedures were included and were stratified into quartiles according to their annual volume of all non-cardiac open aortic procedures. A pre-defined subcohort of cases undergoing open infrarenal repair for iAAA was analysed. The primary outcome was in hospital death; secondary outcomes included acute myocardial infarction, acute kidney injury, acute peripheral ischaemia, and mesenteric thrombosis or embolism. Associations were assessed using multivariable multilevel logistic regression analysis adjusted for age, sex, Elixhauser comorbidity score, and treatment in vascular surgery departments, with random intercepts for hospital and year. Among 100 137 non-cardiac open aortic procedures, 34 100 cases involved infrarenal OAR for iAAA. The overall in hospital mortality rate was 5.9%, ranging from 11.3% in Q1 to 5.2% in Q4. In multivariable analysis, treatment in lower volume hospitals was associated with higher mortality (Q1 vs. Q4: odds ratio [OR] 1.79, 95% confidence interval [CI] 1.30 - 2.47; p < .001). Treatment in vascular surgery departments was associated with reduced mortality (OR 0.83, 95% CI 0.72 - 0.94; p = .005). Higher hospital volume of all non-cardiac open aortic procedures was associated with a lower in hospital mortality rate after infrarenal OAR for iAAA. These findings support centralisation efforts and suggest that minimum case volume requirements should consider the overall non-cardiac open aortic caseload rather than infrarenal procedures alone.