Effect of inferior mesenteric artery ligation on blood flow in the marginal artery-dependent sigmoid colon.

Abstract

Anastomotic leakage after restorative rectal excision may develop from ischemia associated with inadequate blood flow in the marginal artery-dependent colon. We have used laser Doppler flowmetry to measure blood flow change during mobilization of the sigmoid colon before excision of the sigmoid colon or rectum in 26 patients and proximal to the colorectal anastomosis during the first five postoperative days in five patients. There was a significant (p < 0.005) fall (median, 50 percent interquartile range, 41 to 86 percent) in sigmoid colon serosal flow after ligation of the inferior mesenteric artery (IMA) and distal marginal artery (DMA) that was not influenced by the order of vessel ligation. No increase in perianastomotic colonic perfusion was detected during the first five postoperative days. The significant blood flow reduction after ligation of the IMA and DMA supports the hypothesis that anastomotic leakage after restorative rectal excision may result from ischemia associated with inadequate blood flow in the marginal artery-dependent sigmoid colon. Improvement in inadequate intraoperative colonic perfusion from increased collateral circulation is unlikely to develop in the marginal artery-dependent colon during the first five postoperative days.