Effects of VEGF administration following ischemia on survival of the gracilis muscle flap in the rat

The incidence of free flap transplantation failure is only 3% to 5%, yet st ill occurs in cases in which the flap suffers prolonged ischemia. The purpo se of the current study was to determine the effects of vascular endothelia l growth factor (VEGF)-a potent angiogenic agent with a suspected role in t he protection of endothelium-on flap survival in a model of ischemia-reperf usion injury. The model chosen was the rat gracilis muscle flap. A total of 36 adult male Sprague-Dawley rats were divided into three groups (N = 12). One experimental group received VEGF treatment and the other received hepa rin. A third group was treated with saline and served as the control. The g racilis muscle flap was dissected and isolated based on a vascular pedicle originating at the femoral vessels. Following 3.75 hours of ischemia, induc ed by clamping the femoral vessels, either VEGF, heparin, or saline was inf used directly into the pedicle of the flap via a cannula, The flaps were ev aluated both grossly and histologically after 72 hours of reperfusion, Elev en of the 12 flaps from the VEGF group survived, whereas the survival rate was 6 of 12 and 5 of 12 flaps for the heparin- and saline-treated groups re spectively. Flap survival was significantly greater in the VEGF-treated gro up compared with the heparin- and saline-treated groups (p < 0.025, p < 0.0 1 respectively). Furthermore, there was no significant difference between t he heparin and saline groups. These results indicate that VEGF plays a role in reducing the damage that occurs in ischemia-reperfusion injury, and tha t the use of VEGF holds promise as a potential therapy for increasing flap survival.