Facial Nerve Repair by Muscle-Vein Conduit in Rats: Functional Recovery and Muscle Reinnervation

Abstract

The facial nerve is the most frequently damaged nerve in head and neck traumata. Repair of interrupted nerves is generally reinforced by fine microsurgical techniques; nevertheless, regaining all functions is the exception rather than the rule. The so-called "postparalytic syndrome," which includes synkinesia and altered blink reflexes, follows nerve injury. The purpose of this study was to examine if nerve-gap repair using an autologous vein filled with skeletal muscle would improve axonal regeneration, reduce neuromuscular junction polyinnervation, and improve the recovery of whisking in rats with transected and sutured right buccal branches of the facial nerve. Vibrissal motor performance was studied with the use of a video motion analysis. Immunofluorescence was used to visualize and analyze target muscle reinnervation. The results taken together indicate a positive effect of muscle-vein-combined conduit (MVCC) on the improvement of the whisking function after reparation of the facial nerve in rats. The findings support the recent suggestion that a venal graft with implantation of a trophic source, such as autologous denervated skeletal muscle, may promote the monoinnervation degree and ameliorate coordinated function of the corresponding muscles.

Keywords: axotomy; functional recovery; motoneuron; motor end plates; polyinnervation; vibrissae whisking.