[Prevention of colonic ischemia following abdominal aortic aneurysmectomy by measurement of inferior mesenteric artery stump pressure].

To prevent postoperative colon ischemia, the inferior mesenteric artery (IMA) stump pressure measurement was performed in 60 patients undergoing unruptured abdominal aortic aneurysmectomy. IMA stump pressures were more than 40mmHg and IMA/systemic pressure ratios were more than 0.4 in 58 patients. The IMA was ligated in all of these patients. Colon ischemia developed in two of these 58 patients. In one, vigorous retractive trauma to the colon and the mesenterium seemed to be causative, and in the other, division of the branches of the IMA was causative. None of the other 56 patients developed colon ischemia. In remaining two patients, IMA stump pressures were less than 40mmHg and/or IMA/systemic pressure ratios were less than 0.4. In one of these two, reimplantation of the IMA was not performed until 12 hours after ligation of the IMA and postoperative ischemic colitis developed. In the other, the IMA was implanted into the prosthesis and colon ischemia did not develop. These results indicated that IMA stump pressure measurement is simple and very useful method to predict the risk of postoperative colon ischemia following abdominal aortic aneurysmectomy, and when IMA stump pressure or IMA/systemic pressure ratio is less than 40mmHg or 0.4, the IMA should be revascularised.