Novel Risk Score Calculator for Perioperative Mortality after EVAR with Incorporation of Anatomical Factors

Abstract

Hostile proximal aortic neck anatomy has been associated with increased risk of perioperative mortality after endovascular aneurysm repair (EVAR). However, all available mortality risk prediction models after EVAR lack neck anatomic associations. The aim of this study is to develop a preoperative prediction model for perioperative mortality after EVAR incorporating important anatomic factors. Data were obtained from the Vascular Quality Initiative database on all patients who underwent elective EVAR between January 2015 and December 2018. Stepwise multivariable logistic regression analysis was implemented to identify independent predictors and develop a risk calculator for perioperative mortality after EVAR. Internal validation was done using bootstrap of 1000 reps. A total of 25,133 patients were included, of whom 1.1% (N=271) died within 30 days or before discharge. Significant preoperative predictors of perioperative mortality were age (odds ratio [OR], 1.053; 95% CI, 1.050-1.056; P<.001), female sex (OR, 1.46; 95% CI, 1.38-1.54; P<.001), chronic kidney disease (OR, 1.65; 95% CI, 1.57-1.73; P<.001), chronic obstructive pulmonary disease (OR, 1.86; 95% CI, 1.77-1.94; P<.001), congestive heart failure (OR, 2.02; 95% CI, 1.91-2.13, P<.001), aneurysm diameter ≥ 6.5cm (OR, 2.35; 95% CI, 2.24-2.47, P<.001), proximal neck length< 10mm (OR, 1.96; 95% CI, 1.81-2.12; P<.001), proximal neck diameter ≥30mm (OR, 1.41; 95% CI, 1.32-1.5; P<.001), infrarenal neck angulation ≥60° (OR, 1.27; 95% CI, 1.18-1.26; P<.001) and suprarenal neck angulation ≥60° (OR, 1.26; 95% CI, 1.16-1.37; P<.001). Significant protective factors included aspirin use (OR, 0.89; 95% CI, 0.85-0.93; P<.001) and statin intake (OR, 0.77; 95% CI, 0.73-0.81; P<.001), These predictors were incorporated to build an interactive risk calculator of perioperative mortality after EVAR (C-statistic=0.749) CONCLUSION: This study provides a prediction model for mortality following EVAR that incorporates aortic neck features. The risk calculator can be used to weigh risk/benefit ratio when counseling patients preoperatively. Prospective use of this risk calculator may show its benefit in long-term prediction of adverse outcomes.