Improvement of regeneration with predegenerated nerve transplants in silicone chambers

We compared regeneration and reinnervation of target organs after sciatic n erve resection and repair with silicone tubes filled with saline solution o r with a peroneal nerve segment as a nerve transplant versus an autologous sciatic nerve graft leaving either 4 mm or 6 mm gaps. The aims of this stud y were to evaluate the effects of predegeneration and donor immunogenicity of nerve transplants. Functional reinnervation was assessed by noninvasive methods to determine recovery of sweating, sensory and motor functions in t he hindpaw after three months post-operation for 4 mm and four months posto peration for 6 mm gap groups. Morphometrical analysis of the regenerated ne rve were performed at the end of the follow-up. The group with an autograft achieved faster and higher levels of reinnervation for the four functions tested than any of the groups repaired by tubulization. The introduction of a small nerve transplant improved regeneration and reinnervation with resp ect to a saline solution filled tube slightly with a 4 mm gap, but signific antly with a 6 mm long gap. The beneficial effects of the nerve transplant were significantly increased when it was predegenerated, while disappearing when its cellular component was eliminated by repeated freezing. The immun ogenicity of the nerve transplant dramatically affected nerve regeneration, as it was impeded by an heterologous transplant in the tube. In summary, t he use of silicone chambers with an autologous predegenerated nerve transpl ant may be an alternative for repairing long gaps in injured nerves, approa ching the level of success of an ideal autologous nerve graft.