Intestinal ischemia after aortic surgery.

Intestinal ischemia after abdominal aortic surgery is a highly lethal complication. In order to evaluate the pathogenesis, the diagnostic modalities and the best management, in a retrospective review, 12 patients undergoing postoperative small bowel or colonic ischemic lesions were identified between 1983 and 1995. Preoperative occlusion of IMA was present in nine patients, while a selective angiography of SMA demonstrated occlusive disease of peripheral branches in two asymptomatic diabetic patients. No patent IMA was ligated. When possible, hypogastric circulation was preserved by distal anastomosis into iliac bifurcation (4 cases). Postoperative leukocytosis or elevated LDH values were present. Colonscopy showed a suspected ischemic colitis in two patients and necrotic lesions in three cases. One patient died and diagnosis was made at autopsy. Nine patients were submitted to reoperation and a bowel resection with a proximal stoma was performed in seven of them. In two patients, the aorta or iliac artery below the proximal anastomosis and hypogastric artery suffered acute thrombosis, while prosthetic grafts were patent. A coagulation disorder caused thrombosis of intramural arterioles of the small bowel while peripheral branches of SMA were pulsatile. Eight of the patients submitted to relaparotomy died; non-operative management resulted in a left colon late stricture, while the remaining patient survived without sequelae. Overall mortality rate was 66.6%. Symptoms of this complication are not specific and diagnosis is delayed; consequently surgical repair is often unsuccessful. One patient with small bowel necrosis after elective AAA resection survived, which is extremely rare.