Ischemic Colitis Complicating Abdominal Aortic Aneurysm Surgery in the U.S. Veteran

Abstract

Ischemic colitis (IC) is an infrequent but serious complication of abdominal aortic surgery. Prior reports have generally described small, selected populations. The aim of this paper is to evaluate characteristics of clinically diagnosed IC in a large non-referral-based population. Using national Veterans Affairs (VA) computer data sets, we identified all patients with the diagnostic codes for both prosthetic replacement of aorta for abdominal aortic aneurysm and subsequent vascular insufficiency of the intestine in the entire VA population from 1987 to 1991. Clinical information on these patients was then requested from the VA Medical Centers where they received care. Patients demographics, clinical data regarding both the aortic surgery and IC, and survival data were extracted from patient charts and computer records. Of 4957 patients who underwent surgery of the abdominal aorta for infrarenal abdominal aortic aneurysm, 58 (1.2%) also had the code for subsequent IC. In 49/58 (74%), sufficient chart-derived and computer-derived data were available for analysis. The mean age was 69 (range 57–95); all were males. Bloody diarrhea was the most frequent symptom and colonoscopy the most common means of diagnosis. Mean time to diagnosis of IC was 5.5 days after aortic surgery (range 1–21 days). Aneurysmal rupture or perioperative hypotension were present in 35/49 patients. Bowel resection with fecal diversion was required in 32/49 (65%). The overall mortality was 54% but it was 89% if bowel resection for bowel infarction was required. Only 2/12 (16%) of those who required fecal diversion and survived underwent eventual stoma closure. Among 7 patients who received second-look laparotomy for IC, additional bowel resection was required in 6. No patient had aortic graft infection diagnosed during the index hospitalization. The overall mean hospitalization duration after the diagnosis of IC was 38 days (range 1–164). IC following aortic aneurysm surgery in this national patient population is infrequently diagnosed. Emergency aneurysm operation and perioperative hypotension are common in patients who develop IC. The majority of patients diagnosed receive surgical intervention. Most patients who undergo fecal diversion retain their stomas.