The predictive value of the laser Doppler flowmeter for postoperative microvascular monitoring

Reliable postoperative monitoring in microvascular surgery is necessary to improve the low success rate of reexploration after vascular compromise. The use of laser Doppler flowmetry has been evaluated in this study. From November 1985 to January 1988, 79 microvascular operations were monitored postoperatively. These consisted of 45 replants and revascularizations in 34 patients, as well as 34 free vascularized tissue transfers. In the replant and revascularization group, a statistically significant difference in laser Doppler flowmetry readings has been demonstrated between well-vascularized and circulatory impaired patients (p < 0.001). In this study a reliable critical (alarm) value could be defined for replants and revascularizations with a sensitivity of 93% and a specificity of 94%. This critical alarm value can be adjusted according to the individual surgeon's attitude toward reexploration. Similar laser Doppler flowmetry characteristics were seen in patients with free vascularized tissue transfers; however, the numbers in this part of the study were too small to define reliable critical alarm values. The laser Doppler flowmeter is recommended for the postoperative evaluation of tissue after microvascular anastomoses, as it indicates vascular occlusion at an early stage where reexploration is worthwhile.