Visceral ischemia following aortic surgery

Intestinal ischemia after aortic surgery is a rare (1-5%) complication, often with a fatal outcome (greater than 50%). During the period 1974-1987, 554 abdominal aortic operations were performed in our department. 17 patients (3%) were reoperated due to bowel ischemia, ten of these patients died. 12 patients were operated on due to aortic aneurysm (9 emergency operations) and 5 due to occlusive disease. A retrospective analysis of the files of the 17 patients was performed to try to identify the risk patient. Preoperative investigations demonstrated that the inferior mesenteric artery (IMA) was patent in 3 patients and occluded in 5 patients. As to the other 9 patients no information could be found (all with aneurysm). After the primary operation, 11 patients had persistent circulation via at least one of the hypogastric arteries and none of them had persistent circulation via the IMA. 11 patients had bloody diarrhea before reoperation and in 6 patients peritonitis was observed. Rectoscopy was performed in 8 patients and in 7 there was indication of ischemia. The most common finding among the laboratory tests was a rise in the creatinine level which was observed in 10 patients. Other laboratory tests such as blood gases, leucocytes, thrombocytes or temperature were of little predictive value per se. Patients operated on due to ruptured aortic aneurysm are risk patients. No other predictive symptom or sign was found to preoperatively identify the patient at risk for intestinal ischemia. An intraoperative method for evaluating the intestinal blood flow would be of great value when considering selective intestinal vascular reconstruction.