P33. PEG-FUSION TO RESTORE ELECTROPHYSIOLOGICAL CONTINUITY AND FUNCTION AFTER NERVE TRANSECTION

Abstract

PURPOSE: In this study, we tested whether Polyethylene glycol (PEG)-fusion repair of peripheral nerves could improve electrophysiological and behavioral functions in a large animal (swine) model of nerve repair. METHODS: The median and ulnar nerves were both sharply transected above the elbow in Yorkshire pigs (n=2). The median nerve was irrigated with hypotonic calcium-free saline and methylene blue, then repaired with 9-0 sutures in standard fashion. PEG was applied directly to the coaptation site for 1-2min, followed by a final wash with Lactated Ringers solution. Electrophysiological testing of compound action potentials (CAPs) and compound muscle action potentials (CMAPs) was performed to measure if PEG resulted in the re-establishment of electrical connectivity between proximal and distal nerve segments. RESULTS: Electrophysiological testing demonstrated the absence of CAPs or CMAPs after the nerve was repaired with sutures and re-establishment of CAP and CMAPs after application of PEG. Follow up studies 14 days post-operatively showed continual maintenance of CAPs in both pigs, and CMAPs in 1 of 2 pigs, suggesting axonal survival and maintenance of neuromuscular innervation. CONCLUSION: PEG-fusion successfully re-established electrophysiological function after median nerve transection in swine, showing that PEG-fusion can be accomplished in larger animal models. Swine could be a particularly useful model for PEG-fusion of long nerve defects (>3cm) that are not possible in small animal models.