Perfusion parameters and pressure at zero flow in canine gracilis muscle flaps

The perfusion parameters and pressure at zero flow were examined in island gracilis muscle flaps in dogs under sodium pentobarbital anesthesia. Complete surgical isolation of the muscle preparation was obtained. Normal blood flow in denervated muscle in situ was 8.0 +/- 0.8 ml/min/100 g tissue as measured by electromagnetic blood flowmetry. The artery supplying each flap was occluded with a microclip and the drop in pressure distal to the clip was observed. The lowest pressure obtained following occlusion was the pressure at zero flow. A positive pressure at zero flow in the vascular bed was thereby identified at a pressure of 10.3 +/- 1.2 mm Hg.