Electrophysiological study of regenerated rabbit tibial and peroneal nerves: autologous versus non-neural grafts.

In recent years, successful experimental nerve regeneration using extracellular matrix as implants has been reported. In the present study, we compared peripheral nerve regeneration through implants of amnion membrane matrix (AMM) and umbilical cord membrane matrix (UCMM) versus autologous nerve transplantation, bridging gaps 8-12 mm in length in rabbit tibial and peroneal nerves. The data are based on direct nerve stimulation and recording of somatosensory evoked potentials (SEPs) and muscle action potentials (MAPs) to measure functional recovery after these different types of neuroplastic bridging. Incomplete regeneration was demonstrable as missing SEPs (15-22%), missing MAPs (17-42%), a mean delay of SEPs and distal motor latencies of approximately 40-50% compared with a normal control group, and slowed motor conduction velocities by approximately 50%. There were no significant differences between the three different types of neuroplastic bridging. Most of the AMM and UCMM implants (80-100%), but none of the autologous nerve transplants, caused inadequate connections with peripheral targets. We conclude that extracellular matrix implantation represents a useful experimental model for studying the biological basis of nerve regeneration, but does not yet serve as a tool for therapeutic applications.