Repair of peripheral nerve gap with xenogeneic acellular graft combined with nerve growth factor

Objective To evaluate peripheral nerve regeneration in the adult Wistar rats whose nerve gaps were repaired by acellular basal lamina tubes combined with nerve growth factor (NGF).Methods Fifteen adult Wistar rats were divided randomly into 3 even groups. A 1.0 cm long gap was created in the continuity of the sciatic nerve in each rat. The rabbit tibial nerve was excised to make xenogeneic acellular nerve basal lamina tubes, the ultrastructure of which was observed by electron microscopy and HE coloration. The MHC Ⅱ antigen contents were examined by flow cytometry before and after the rabbit tibial nerves were treated with chemical detergents. In group A, xenogeneic acellular basal lamina tubes were grafted with NGF; in group B, only xenogeneic acellular basal lamina tubes were grafted; in group C, autogenous nerves were grafted. The nerve functional restoration was observed by electrophysiological experiments in all rats one month postoperatively in terms of motor evoked potential of the musculus triceps surae and the motor conduction velocity at the grafted sciatic nerve segments. Morphological and morphometric analyses were done by optical microscopy, electron microscopy and immunohistochemical techniques. Results The nerve regeneration, nerve fiber arrangement and nerve function reconstruction in group A were better than in group B, and similar to those in group C. Conclusions The rabbit tibial nerve treated with chemical detergents can be grafted to repair the nerve gap in rats. As the acellular basal lamina tubes combined with NGF can better improve nerve regeneration by enhancing the growth of regenerating axons and migration of Schwann cells than those without NGF, they may be a good substitute for nerve grafts. Key words: Nerve growth factor;  Nerve graft;  Transplantation, heterologous