Intraoperative assessment of blood flow and tissue viability in small-bowel ischemia by laser Doppler flowmetry

Laser Doppler flowmetry (LDF) was used for intraoperative assessment of blood flow and tissue viability in 23 patients with small-bowel ischemia, and the signal levels in ischemic bowel were compared with previously obtained reference values from normal ileum and jejunum. The average LD signal was 6.8 +/- 2.9 V in nonischemic bowel, 0.3 +/- 0.2 V in segments with macroscopically irreversible ischaemia and 2.1 +/- 1.2 V in segments with clinically uncertain viability. In 12 cases with strangulated bowel it was possible, following LDF, to avoid resecting nine of ten bowel segments with clinically uncertain viability. In four of the six patients with mesenteric vascular occlusion, LDF indicated that clinical judgement had underestimated the extent of severe ischemia. Among the five cases of iatrogenic ischemia there was one failure, with postoperative irreversible ischemia and anastomotic leakage. LDF is concluded to be a useful method for intraoperative assessment of intestinal blood flow in patients with small-bowel ischemia and it provides substantial information on tissue viability affecting surgical strategy.