REGENERATION ACROSS STEPPING-STONE NERVE GRAFTS

The ability of small nerve segments interposed between synthetic condu its to increase the total nerve gap distance across which successful n erve regeneration would occur was studied. Fifty adult male Lewis rats were randomized into five groups. In Group I a segment of resected sc iatic nerve was repaired by a nerve graft. Group II had alternating si licone tubing/nerve graft/silicone tubing replacement of the resected nerve segment (single stepping stone group). Group III had silicone tu bing/nerve graft/silicone tubing/nerve graft/silicone tubing repair of the nerve deficit (double stepping stone). Group IV had a single long silicone conduit repair. Group V control underwent a sham operation. Nerve regeneration was evaluated using walking track pattern analysis, electrophysiologic assessment and histomorphological evaluation. 'Ste pping stone nerve grafts' enhanced regeneration across nerve gaps in c omparison to a single long conduit, but were inferior to a single long nerve graft. In the repair of long nerve gaps, the use of multiple sh ort conduits with interposed short nerve segments could provide a sour ce of trophic factors to enhance regeneration.