Intestinal ischemia complicating abdominal aortic surgery.

A 9-year experience with 2137 patients undergoing infrarenal abdominal aortic reconstruction was reviewed to determine both the incidence of intestinal ischemia and the clinical, anatomic, and technical factors associated with this complication of aortic surgery. A total of 24 (1.1%) patients had overt intestinal ischemia, documented by reoperation or endoscopic findings. Of these, colon ischemia occurred in 19 (0.9%) and small bowel ischemia developed in 5 (0.2%) patients. The incidence after elective operation for aneurysmal or occlusive disease did not differ, but patients with ruptured aneurysms and those undergoing reoperative procedures for total graft replacement were at higher risk. Preoperative angiography was most helpful in ascertaining risk. Ligation of a patent inferior mesenteric artery was the most common (74%) feature in patients with colon ischemia. With preexisting inferior mesenteric artery occlusion, impairment of collateral circulation was attributable to superior mesenteric artery disease, dissection or retractor injury, prior colon resection, or exclusion of hypogastric perfusion. Bloody diarrhea was the most frequent postoperative symptom and colonoscopy the most reliable means of diagnosis. One half of patients with colon ischemia required resection after late recognition of perforation. All cases of small bowel ischemia were related to superior mesenteric artery disease or injury or use of suprarenal clamping. The overall mortality rate was 25% but rose to 50% if bowel resection was required. Intestinal ischemia remains an infrequent but serious complication of aortic surgery. Despite a multifactorial cause, identification of patients at increased risk can lead to operative strategies to reduce its occurrence.