PREDEGENERATED NERVE ALLOGRAFTS VERSUS FRESH NERVE ALLOGRAFTS IN NERVE REPAIR

This study reevaluated the possibility of using predegenerated nerves as donor nerve allografts for nerve repair and compared the results of functional recovery to those obtained after standard, fresh nerve all ograft repair. Twenty donor rats underwent a ligature/section of the l eft sciatic nerve 4 weeks before nerve graft harvesting. Forty recipie nt rats underwent severing of the left sciatic nerve leaving a 15-mm g ap between the nerve stumps. Graft repair was undertaken using either the predegenerated left sciatic nerve of the 20 donor rats (predegener ated group, 20 recipient rats) or the normal right sciatic nerve of th e 20 donor rats (fresh group, 20 recipient rats). Recovery of function was assessed by gait analysis, electrophysiologic testing and histolo gic studies. Walking tracks measurements at 2 and 3 months, electromyo graphy parameters at 2 and 3 months, peroperative nerve conduction vel ocity and nerve action potential amplitude measurements at 3 months, a s well as assessments of myelinated nerve fiber density and surface of myelination showed that fresh and predegenerated nerve grafts induced a comparable return of function although there was some trend in high er electrophysiologic values in the predegenerated group. The only sli ght but significant difference was a larger mean nerve fiber diameter in the nerve segment distal to a predegenerated nerve graft compared t o a fresh nerve graft. Although our study does not show a dramatic lon g-term advantage for predegenerated nerve grafts compared to fresh ner ve grafts, their use as prosthetic material is encouraging. (C) 1997 A cademic Press.