Evaluation of peripheral nerve regeneration across an 80-mm gap using a polyglycolic acid (PGA)--collagen nerve conduit filled with laminin-soaked collagen sponge in dogs

We evaluated peripheral nerve regeneration using a novel artificial nerve conduit. The conduit was made of a polyglycolic acid(PGA) - collagen tube filled with laminin- soaked collagen sponge. We implanted this nerve conduit across an 80mm gap in the peroneal nerve of dogs. Histological observation 12 months after implantation showed numerous unmyelinated and myelinated nerve fibershad regenerated beyond the gap. Neurofilaments were widely observed immunohistochemically in the regenerated nerve segments. These findings indicated that newly regenerated axons had extended across the gap and connected into the distal nerve segments. Compound muscle action potentials(CMAPs) and somatosensory evoked potentials (SEPs) were recorded in all dogs. At 12 months, the CMAPs indicated complete recovery, while the SEPs showed incomplete but substantial recovery. Walking patterns had returned to near-normal 12 months after implantation. Use of this nerve conduit can lead to peripheral nerve elongation and favorable functional recovery across a wider nerve gap.