Intramuscular administration of vascular endothelial growth factor augmenting collateral circulation in a rat...

This study evaluated the effect of exogenous vascular endothelial growth factor (VEGF) on augmentation of collateral circulation in a rat hindlimb replantation model. Twenty-eight rats, divided into four groups, underwent right hindlimb replantation. In experimental Group 1, the rats received daily intramuscular VEGF injections (1 microg/kg). In Group 2, the rats received 25 microg/kg VEGF injections. In Group 3, the rats received 50 microg/kg VEGF injections. In Group 4, the control group, rats received saline injections. Seven days after replantation, the repaired femoral vessels were excised. Seven days after excision of the femoral vessels, toe necrosis ratios of the replanted hindlimbs were grossly examined, and calf blood pressures were measured. Angiography was performed and muscle tissue was biopsied for histology. The results showed that administration of VEGF significantly decreased toe necrosis and improved calf blood pressure ratio, angiographic score, and capillary density in the replanted hindlimbs that underwent late vessel excision. The effect of VEGF was significantly dose-dependent. The authors conclude that VEGF can augment angiogenesis and collateral vessel formation in replanted limbs, and improve survival in replanted limbs with potential late arterial insufficiency.