Cat peripheral nerve regeneration across 50 mm gap repaired with a novel nerve guide composed of freeze-dried alginate gel

We have developed a novel artificial nerve guide composed of biodegradable freeze-dried alginate gel covered by polyglycolic acid mesh, and evaluated its effect on peripheral nerve regeneration, using a 50-mm gap cat sciatic nerve model. Functional reinnervation of motor and sensory nerves occurred 13 weeks after implantation, as demonstrated by recovery of compound muscle action potential (CMAP) and somatosensory evoked potential (SEP). For hist ologic evaluation, samples of tissue were harvested from the grafted materi al segment 7 months after operation. Many newly developed nerve fasciculi w ere found, and the implanted nerve guidance material had completely disappe ared with little inflammation. These results indicate that freeze-dried alg inate gel allows the nerve to regenerate across longer gaps than described in previous literature. (C) 1999 Elsevier Science ireland Ltd. All rights r eserved.