Comparison of venous drainage in reverse-flow island flaps: an experimental study of the rabbit saphenous fasciocutaneous flap

Abstract

The mechanism of venous drainage in reverse-flow island flaps was investigated using the saphenous fasciocutaneous flap in New Zealand White rabbits. Ten animals were allocated into two groups of 10 flaps. In group I (left limb), the distal vascular pedicle (one saphenous artery and two venae comitantes) was not disturbed, maintaining the communicating and collateral branches intact. In group II (right limb), it was separated microsurgically from each other for 3 cm. Intravenous pressure was measured at 5, 15, 30, and 60 minutes after tourniquet release. The values of group II at 30 and 60 minutes were significantly lower (p<0.01) than those of group I. Ten days after flap elevation, the mean survival area of group I (95%) and group II (100%) was not significantly different. Histological examination of the vascular pedicle showed the saphenous veins in group II were more dilated than those of group I. These findings suggest that venous retrograde return in reverse-flow island flaps can be achieved more easily through a "direct incompetent valves route" than through a "circuitous communicating and collateral bypass route."