Risk Factors of Postoperative Intestinal Ischemia After Abdominal Aortic Aneurysm Repair

Abstract

Introduction - Intestinal ischemia remains a complication following abdominal aortic aneurysm (AAA) repair associated with a high mortality.1-6 The influence of possible risk factors for developing postoperative intestinal ischemia needs clarification. We sought to define predictors as well as the related mortality and to form a prediction model with the predictiors found. Methods - A nationwide population-based cohort study of 9433 patients who underwent an AAA operation between 2014 and 2016 was conducted. Potential risk factors were determined by reviewing prior studies and univariate analysis. With logistic regression analysis independent predictors of intestinal ischemia were established. These variables were used to form a prediction model. Results - Intestinal ischemia occurred in 267 patients (2.8%). Rupture of AAA was the most important predictor of developing intestinal ischemia (odds ratio [OR], 5.9, 95% confidence interval [CI]4.4-8.0), followed by having a suprarenal AAA (OR 3.4; CI 1.1-10.6). Associated procedural factors were open repair (OR 2.8; 95%CI 1.9-4.2), blood loss >1L (OR 3.6; 95%CI 1.7-7.5) and prolonged operating time (OR 2.0; 95%CI 1.4-2.8). Patient characteristics included having peripheral arterial disease (OR 2.4; 95%CI 1.3-4.4), female gender (OR 1.7; 95%CI 1.2-2.4), renal insufficiency (OR 1.7; 1.3-2.2) and pulmonary history (OR 1.6; 95%CI 1.2-2.2). Age <68 proved to be a protective factor (OR 0.5; 95%CI 0.4-0.8). Associated mortality was higher in patients with intestinal ischemia versus patients without (50.6% vs 5.1%, p<.001). A prediction model with an excellent AUC=0.878 (95% CI 0.860-0.896) could be formed. Conclusion - The prediction model can be used to identify patients at high risk for developing intestinal ischemia and possibly lower the mortality risk.