Hypoglossal-facial nerve neurorrhaphy with predegenerated sural nerve graft for incomplete facial palsy in rats

Abstract

Objective For the treatment of persistent incomplete facial palsy,we investigated in rats a modified method using hypoglossal-facial nerve side-to-side neurorrhaphy with predegenerated nerve graft(PNG).Methods 28 adult male Fisher 344 rats were grouped into A (intact),B (complete facial palsy),C (incomplete facial palsy),D (incomplete facial palsy repair-cut PNG) and E (incomplete facial palsy repair-cut facial nerve).The treatment was assessed by the angle α analysis,electrophysiological examination,electron microscopy analysis and retrograde labeling.Results The group D was found a higher recovery of facial symmetry compared to group C (P ＜ 0.01).MAPs displayed significantly greater surface values in group D compared with group C (P ＜ 0.01).The analysis of semithin sections in distal facial nerve showed numerous regenerating myelinated axons (P ＜ 0.01).There were 83 ±48 and 284 ± 80 CTB Alexa 555 labeled neurons in group D,respectively,in the right hypoglossal and facial nuclei 4 months after hypoglossal-facial nerve neurorrhaphy.Conclusions This study demonstrated that hypoglossal-facial nerve side-to-side neurorrhaphy through a predegenerated nerve graft could lead to rapid functional benefits for persistent incomplete facial palsy. Key words: Facial nerve injuries; Anastomosis,surgical; Graft ; Incomplete facial palsy; Rats