Determining variations in colonic circulation during aortic surgery.

The aim of this study was to compare transanal Doppler examination, intraoperative angiography via the inferior mesenteric artery, and the inferior mesenteric artery stump pressure measurement during abdominal aortic surgery to assess the collateral circulation to the inferior mesenteric artery bed. Transanal Doppler examination revealed that the collateral circulation depended on the superior mesenteric artery in 25 patients (superior mesenteric artery-dominant group), the inferior mesenteric artery in two patients (inferior mesenteric artery-dominant group), and the internal iliac artery in one patient (internal iliac artery-dominant group). The mean (+/-S.D.) inferior mesenteric artery stump pressure index was 0.65 (+/-0.12) in the superior mesenteric artery-dominant group, which was significantly different from 0.43 (+/-0.00) in the inferior mesenteric artery- and internal iliac artery-dominant groups. The Intraoperative angiography showed the meandering mesenteric artery clearly in the superior mesenteric artery-dominant group. The Transanal Doppler examination as well as inferior mesenteric artery stump pressure measurement were useful methods to assess a dominant artery to the inferior mesenteric artery bed and colonic viability.