LAUSR

OBJECTIVE Conflicting annual procedure volumes are endorsed among different watchdog groups and professional societies, which obscure credentialing paradigms. There has been ample focus on surgeon volume to date, but less attention surrounding the impact of center volume. Specifically, is center volume a better proxy for high-quality care? This study aimed to measure the association of center volume on open AAA repair (OAR) outcomes and failure to rescue (FTR). METHODS All elective OARs (2003-2020) in the SVS-VQI were reviewed (n=9,791). FTR was defined as in-hospital death after experiencing a complication (cardiac, stroke, pulmonary, renal, colonic ischemia, return to the OR for bleeding). Annual center volume (n=218 hospitals) was calculated and volume quartiles (Q1≤3, Q2 4-6, Q3 7-10, Q4>10 procedures/year) were derived for comparison. Logistic regression was used to estimate the effect of center volume and determine predictors of FTR. RESULTS Center volume quartiles and FTR varied significantly: (Q4, 2.5% vs. Q1-Q2, 4.9%; p<.0001; overall FTR, 3.1% [n=302]). Patients were demographically similar among quartiles. High-volume centers used epidural anesthesia more commonly (Q4-53% vs. Q1-31%; p<.0001) but were less likely to employ thrombectomy (Q4-5% vs. Q1-10%; p<.0001) or any concomitant procedure (Q4-19% vs. Q1-22%; p=.05). High-volume centers had lower rates of pulmonary, renal, and overall complications (pulmonary: Q4-7% vs. Q1-2, 8-11%; renal: Q4-16% vs. Q1-2, 19%-21%; p<.0001; overall mean number of complications: Q4-0.46 vs. Q1-0.52; p=.0008). Crude 30-day and 1-year mortality rates were reduced at higher volume centers (30-day: Q4-3% vs. Q1-Q2, 6%; p<.0001; 1-year: Q4-7% vs. Q1-Q2, 10-11%; p<.0001). A strong inverse relationship between center volume and FTR was identified (p<.0001). In adjusted analysis, OARs performed in high-volume centers (Q4 vs. Q1) had a 50% risk reduction in FTR (OR 0.48, 95%CI 0.3-0.8; p=.004). Among complications, return to the OR for bleeding was most likely to result in FTR (OR 11.8, 95%CI 4.3-33; p<.0001). There was a 24-fold increased risk of FTR in patients experiencing ≥ 3 complications (OR 24 vs. one complication, 95%CI 17-35; p<.0001). CONCLUSIONS Center volume is strongly associated with significantly diminished FTR, reduced complications, and need for surgical adjuncts during OAR. These findings highlight the utility of center volume as an effective proxy to ensure high-quality aneurysm care.