The influence of congestion and ischemia on survival of an experimental vascular pedicle island flap.

We investigated the relationship between the survival rate of experimental rat pedicle island flaps and mild vascular insufficiency, using a flap designed to induce constant distant necrosis. To eliminate individual variation, the vasculature of each flap was evaluated by injecting dye prior to ligating either or both of the pedicle vessels. Seventy-five male Wistar rats divided into four groups were used. Six of the rats died, so 69 rats were evaluated. Statistically, the dye distance of each group was the same. In the control group of 29 rats, survival length was directly proportional to dye distance. Although the mean values of the survival length minus the dye distance of each flap (delta S.L.) in the venous inadequacy group were not different from those of the control group, there was significant difference between the mean values of the arterial insufficiency and the venous inadequacy plus arterial insufficiency groups and those of the control group. In the pedicle island flap, mild venous inadequacy was less responsible for necrosis when the arterial inflow was sufficient. However, when the arterial inflow was impaired, even mild venous inadequacy affected flap survival.