Signal averaging and waveform analysis of laser Doppler flowmetry monitoring of porcine myocutaneous flaps: I. Acute assessment of flap viability.

Postoperative monitoring of microvascular free-tissue transfer is essential to the early identification and correction of vascular compromise. Laser Doppler flowmetry is a noninvasive monitor of capillary bed perfusion. Its current clinical use requires continuous monitoring and trend analysis to detect changes in capillary perfusion. This study investigated the hypothesis that signal averaging of laser Doppler flowmetry output triggered by a fixed point in the cardiac cycle would provide accurate information about the microvascular flow patterns not dependent on trend analysis. These results indicate that averaged waveform analysis allowed for a rapid, objective, and statistically significant distinction between a viable myocutaneous flap and one with vascular compromise in a porcine model. Moreover, this technique allows for distinction between venous and arterial insufficiency.