Histomorphometric Analysis of Femoral and Sciatic Nerve Regeneration in a Rat Hindlimb Allotransplantation Model.

BACKGROUND

Peripheral nerve regeneration is essential for functional recovery after traumatic limb injury or limb transplantation. With the use of immunosuppression, it has the capacity to provide regeneration and function equal to that of an autograft. The purpose of this study was to determine whether there is any difference in regeneration and rejection response between peripheral femoral and sciatic nerve in rat hindlimb allotransplantation model.

METHODS

The hindlimbs of recipient Fischer 344 rats were amputated at the mid-thigh and the donor and recipient femurs were joined by an intramedullary rod. The femoral and sciatic nerves were repaired with 10-O nylon end-to-end suture followed by vessel, muscle, and skin closure. The control group received auto-transplantation and the experimental group received allo-transplantation from Sprague-Dawley donor rats. The recipients were treated with an immunosuppressive agent, FK506 (2 mg/kg), for the observation period. Both sciatic and femoral nerves were harvested 10 weeks after operation and histomorphometric analysis was conducted between these 2 nerves and control group.

RESULTS

The sciatic nerve showed better regeneration, with significantly increased percentage nerve, fiber count, and density (P < .05), but demonstrated more immune cell proliferation relative to femoral nerve.

CONCLUSIONS

The data showed that there are some differences in axonal regeneration capacity and immune response between large peripheral nerves.