LABELED SCHWANN-CELL TRANSPLANTS VERSUS SURAL NERVE GRAFTS IN NERVE REPAIR

This study evaluated the ability of Schwann cell transplants to enhanc e the recovery of function in injured nerves and compared the results to those produced by sural nerve grafts. Schwann cells were isolated f rom sciatic nerves, prelabeled with gold fluorescent dye admixed with collagen gel, and placed in resorbable collagen tubes. Twenty-four adu lt rats underwent severing of the bilateral sciatic nerves, with a 10- mm gap between the nerve stumps. The rats were then divided into two g roups. A collagen tube with implanted Schwann cells was implanted in o ne leg of the Group I rats, and the contralateral leg served as a cont rol and was repaired with a collagen tube filled with collagen gel onl y. The Group Il animals received conduits packed with labeled Schwann cells in one leg to bridge the 10-mm gap; the contralateral leg was re paired with an autogenous sural nerve graft. Recovery of function was assessed physiologically and morphologically. Nerve conduction velocit y and nerve action potential amplitude measurements showed that the Sc hwann cell implants induced return of function comparable to that of t he sural nerve grafts. Morphological assessments of myelination sugges ted a tendency toward greater numbers of myelinated axons in Schwann c ell implants than in sural nerve grafts. Anatomical analyses of gold f luorescent dye showed both high viability of prelabeled Schwann cells at 120 days after transplantation and migration as far as 30 mm away f rom the implant site.