Intraoperative laser Doppler flowmetry: a predictor of ischemic injury in acute mesenteric infarction.

Mesenteric ischemia following intestinal infarction caused by occlusion of the superior mesenteric artery is a rare and devastating disease. The overall mortality is a high as 80%. The purpose of this prospective study was to investigate erythrocyte flux to defined areas of the intestine immediately after laparotomy by using laser Doppler flowmetry (LDF) assessment. We tried to predict the intestinal viability and recovery of the small bowel, and further tried to define the level of critical perfusion below which intestinal resection is indicated. 13 patients undergoing surgery for acute mesenteric ischemia were prospectively studied. Multiple LDF assessment of bowel blood flow (4 records/segment) were performed on 48 ischemically injured bowel segments intraoperatively. All patients underwent a second-look procedure within 48 h to define the viability of the previously suspicious segments. All 18 resected bowel segments were histologically evaluated for the extent of ischemia. In addition clinical judgement as well as histological findings were compared with the laser Doppler records. There was a 19% (9 of 48) incidence of histologically proven nonviable bowel segments with a significant decrease in intestinal erythrocyte flux below 50 perfusion units intraoperatively in all those patients. But there was a 50% (9 of 18) incidence of nonviable segments among the clinically proven viable and subsequently resected segments, only. Therefore, clinical judgement alone had a overall accuracy of 87% and a predictive value of only 69%, compared to the 100% overall accuracy, sensitivity and predictive values of LDF assessment. The results of this study demonstrate that LDF is a sensitive guide and feasible method to evaluate and define the viability of ischemically injured intestine.