Microsurgical repair of nerve lesions with nerve grafts: the effect of nerve growth factor 7S

Abstract.

This study investigated the effect of local administration of nerve growth factor 7S (NGF-7S) on the axonal regrowth of mixed peripheral nerves through nerve grafts. Sixty male Wistar rats were randomized into two groups (n=30). A defect 12 mm long in the right sciatic nerve was created and repaired with a nerve autograft. NGF-7S (group A) or normal saline (group B-control) was locally administered daily during the first 3 weeks. For this purpose a subcutaneously implanted reservoir connected to a silicone tube was used. Electrophysiological and histological-morphometric studies were carried out 4, 6, 8, 10 and 12 weeks postoperatively (subgroups a, b, c, d, and e, respectively, n=6 each). Data analysis showed that: (a) the evoked muscle action potential and (b) the orientation, number, myelin thickness, and diameter of myelinated fibers were better in the NGF-7S than in the control group. These findings present strong evidence of the beneficial effect of NGF-7S on peripheral nerve regeneration through nerve grafts.