Novel surgical quality metrics in abdominal aortic aneurysm repair

Existing surgical quality metrics have limited utility, are primarily used for high-mortality procedures, and often fail to account for differences in non-fatal outcomes. Our objective was to develop more comprehensive, novel surgical quality metrics, for patients undergoing abdominal aortic aneurysm (AAA) repair.

Non-ruptured open and endovascular AAA repair (EVAR) from the Vascular Quality Initiative database were studied, 2016-2019. A win was defined as AAA repair without major complication (in-hospital) or mortality (in-hospital or within 30 days). Centers were divided into quality quartiles based on performance in two novel win-based metrics: (1) Wins Above Average (WAA) and (2) weighted Wins Above Average (wWAA). Patient-level and center-level analyses compared demographics and outcomes between "best" and "worst" quartiles, including wins, mortality, and failure to rescue (FTR) rates. Additional patient-level analyses were performed based on center stratification into volume quartiles. Correlation in surgical quality for open repair and EVAR was determined at centers performing both procedures.

Overall, 3683 patients underwent open repair and 21,165 patients underwent EVAR. For open repair, crude rates of win, mortality, and FTR were 62.8%, 4.2%, and 10.3%, respectively. For EVAR, crude rates for win, mortality, and FTR were 94.4%, 1.1%, and 12.3%, respectively. When stratified by wWAA, patients undergoing open repair at "best" quartile centers had a higher win rate (72.0% vs 52.7%; risk ratio [RR], 1.37; 95% confidence interval [CI], 1.28-1.46) and lower mortality (3.1% vs 6.2%; RR, 0.50; 95% CI, 0.33-0.74) compared with "worst" quartile centers. Similarly, for EVAR, "best" quartile centers had a higher win rate (96.2% vs 92.1%; RR, 1.04; 95% CI, 1.03-1.05), lower mortality (0.4% vs 2.2%; RR, 0.19; 95% CI, 0.13-0.29), and a lower FTR rate (5.7% vs 17.9%; RR, 0.32; 95% CI, 0.18-0.56) compared with "worst" quartile centers. Stratification by volume showed that high-volume centers demonstrated improved wWAA for open repair (P = .04) but not for EVAR (P = .3) compared with low-volume centers. For centers that performed both open repair and EVAR, there was no correlation in quality as determined by wWAA (r = -0.056; P = .6).

wWAA is a novel, risk-adjusted, complication-weighted surgical quality metric that also accounts for volume differences. wWAA successfully distinguishes high- and low-quality centers for both open AAA repair and EVAR. This methodology is potentially broadly applicable for measuring surgical quality.