Ischemic colitis following repair of ruptured abdominal aortic aneurysm.

Seven patients--six of whom died--underwent surgical repair of a ruptured abdominal aortic aneurysm and developed postoperative ischemic colitis. All patients were male, with a mean age of 62 years. Resection of the necrotic colon with a colostomy was necessary within the first postoperative week for the six patients who did not survive and on the 40th postoperative day for the patient who lived. The colon is vulnerable to ischemic necrosis after an aortic rupture because of tissue hypoperfusion and impaired mesenteric artery circulation due to preexistent occlusive disease. In high-risk patients, fiberoptic colonoscopy and examination of stool for occult blood, with immediate abdominal exploration, if necessary, are important in the early postoperative period. Symptoms may develop insidiously when tissue damage is limited to the mucosal layer, but delay in resecting the ischemic segment allows for the extension of necrosis, with perforation.