Evoked muscle action potentials from regenerated rat tibial and peroneal nerves: Synthetic versus autologous interfascicular grafts

Abstract

To compare peripheral nerve regeneration across bridging synthetic tubular implants with ordinary autologous transplantation, we recorded evoked muscle action potentials 3 months after transection, following direct stimulation of rat tibial and peroneal nerves. Significantly, with autologous transplantation we were able to evoke compound muscle action potentials in all but one case (this having a 15-mm gap). Pooling the groups together, compound action potentials could be recorded in 15 of 45 cases that had regenerated through 13- to 16-mm gaps. Potentials in the synthetic implant-treated group tended to show more temporal “scattering” in the late phases of the EMG response. No differences were found in compound muscle action potential amplitudes and duration, or terminal motor conduction velocity, between both experimental groups, between different artificial tubuli, between different gap lengths, or between the peroneal and tibial nerves. The overall values were remarkably lower than in nontransected controls, about 25% of the compound muscle action potential normal amplitude voltage and 60% of the terminal motor conduction velocity.