Risk factors and outcomes of postoperative ischemic colitis in contemporary open and endovascular abdominal aortic aneurysm repair.

Objective: Postoperative ischemic colitis (IC) can be a serious complication following infrarenal abdominal aortic aneurysm (AAA) repair. We sought to identify risk factors and outcomes in patients developing IC after open AAA repair and endovascular aneurysm repair (EVAR).

Methods: The American College of Surgeons National Surgical Quality Improvement Program database was used to examine clinical data of patients undergoing AAA repair from 2011 to 2012 who developed postoperative IC. Multivariate regression analysis was performed to identify risk factors and outcomes.

Results: We evaluated a cohort of 3486 patients who underwent AAA repair (11.6% open repair and 88.4% EVAR). The incidence of postoperative IC was 2.2% (5.2% for open repair and 1.8% for EVAR). Surgical treatment was needed in 49.3% of patients who developed IC. The mortality of patients with IC was higher than that of patients without IC (adjusted odds ratio [AOR], 4.23; 95% confidence interval [CI], 2.26-7.92; P < .01). The need for surgical treatment (AOR, 7.77; 95% CI, 2.08-28.98; P < .01) and age (AOR, 1.11; 95% CI, 1.01-1.22; P = .01) were mortality predictors of IC patients. Predictive factors of IC included need for intraoperative or postoperative transfusion (AOR, 6; 95% CI, 3.08-11.72; P < .01), rupture of the aneurysm before surgery (AOR, 4.07; 95% CI, 1.78-9.31; P < .01), renal failure requiring dialysis (AOR, 3.86; 95% CI, 1.18-12.62; P = .02), proximal extension of the aneurysm (AOR, 2.19; 95% CI, 1.04-4.59; P = .03), diabetes (AOR, 1.87; 95% CI, 1.01-3.46; P = .04), and female gender (AOR, 1.75; 95% CI, 1.01-3.02; P = .04). Although open AAA repair had three times higher rate of postoperative IC compared with endovascular repair, in multivariate analysis we did not find any statistically significant difference between open repair and EVAR in the development of IC (5.2% vs 1.8%; AOR, 1.25; 95% CI, 0.70-2.25; P = .43).

Conclusions: Postoperative IC has a rate of 2.2% after AAA repair. However, it is associated with 38.7% mortality rate. Rupture of the aneurysm before surgery, need for transfusion, proximal extension of the aneurysm, renal failure requiring dialysis, diabetes, and female gender were significant predictors of postoperative IC. AAA patients who develop IC have four times higher mortality compared with those without IC. Surgical treatment is needed in nearly 50% of IC patients and is a predictor of higher mortality.