Hypoglossal-facial nerve reconstruction with predegenerated nerve graft for treatment of complete facial palsy

Abstract

Objective To study the hypoglossal-facial nerve anastomosis method combined with predegenerated nerve graft for the treatment of facial palsy in adult rats after facial nerve injury.Methods 30adult male Fisher 344 rats were grouped into A (intact),B (injury),C (reconstruction at 1 week after injury),and D (reconstruction at 9 weeks after injury).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 amplitude and surface values in the group D compared with group C (P ＜ 0.05).Analysis of semithin sections showed numerous regenerating myelinated axons and there were 1 239 ± 192 和 559 ± 224 myelinated axons in group C and group D,respectively.The analysis of ultrathin sections found that the majority (＞90％) of myelinated axons were 1.0 ～6.5 μm in their greatest diameter (including the thickness of their myelin).Among these axons,41％ in group C were larger than 3 μm in their greatest diameter,as compared with only 29％ in group D.There were significantly more double-labeled (CTB-Alexa555 and FG) hypoglossal motoneurons in the rats treated immediately as compared with the number in rats treated after a delay of 9 weeks (P ＜ 0.05).Conclusions The hypoglossal-facial nerve anastomosis method combined with predegenerated nerve graft was effective for the treatment of complete facial palsy in adult rats after facial nerve injury. Key words: Facial nerve injuries ; Anastomosis,surgical; Graft; Rats