Effect of Vascular Endothelial Growth Factor Administration on Nerve Regeneration after Autologous Nerve Grafting.

BACKGROUND

The aim of this study was to evaluate the effect of vascular endothelial growth factor (VEGF) administration around the autologous nerve graft on nerve recovery in a rat model.

METHODS

A total of 69 rats were randomly divided into three experimental groups. A 10-mm sciatic nerve defect was made and reconstructed with the reversed nerve segment. Group I received an osmotic pump with saline, group II received an osmotic pump with VEGF, and group III added a silicone tube around the nerve graft to decrease the surrounding blood supply. Nine animals in each group were sacrificed on day 3 to evaluate improvement in new vessel formation. In each group 14 animals were sacrificed at 16 weeks after the initial procedure to evaluate the functional motor nerve regeneration using compound muscle action potential, isometric tetanic force, wet muscle weight, and nerve histomorphometry.

RESULTS

The average vascular density on day 3 was 10.7% in group I, 21.4% in group II, and 0.9% in group III. These differences were significant. However, the average maximum isometric tetanic force at 16 weeks was 54.4% in group I, 57.5% in group II, and 47.6% in group III. No difference was found with or without VEGF administration. Histomorphometric analysis was also not significantly different between the groups.

CONCLUSIONS

New vessel formation on autologous nerve graft was enhanced by VEGF administration. However, the neovascularization effect of VEGF administration did not translate into better motor nerve recovery.