title: Peripheral facial nerve regeneration using collagen conduit entubulation in a cat model.
abstract: OBJECTIVE
  Facial nerve (FN) injuries are functionally, psychologically, and financially debilitating. Facial nerve autograft repairs produce significant donor nerve morbidity and functional results that rarely exceed House-Brackmann (HB) grade III over VI. In this study we sought to enhance FN regeneration via collagen conduit entubulation.
  
  
  METHODS
  Five control cats underwent right ("cut-side") FN transection and immediate microsurgical anastomosis repair. Five experimental cats underwent identical repairs plus collagen conduit entubulation of each anastomosis.
  
  
  RESULTS
  Postoperative behavioral observations revealed gradual FN functional recovery in all cats, who attained adapted HB grades of II to III over VI after 6 weeks. Electromyographic latencies and amplitudes from the bilateral orbicularis oculi and orbicularis oris muscles indicated restoration of FN continuity in all 10 cats. In comparison with FN repairs without conduits, repairs with conduits significantly enhanced recovery of amplitude in cut-side orbicularis oculi muscles (p = .037) and latency in cut-side orbicularis oris muscles (p = .048). In comparison with intact left ("uncut-side") FN latencies and amplitudes, more statistically significant differences in cut-side FN function were observed in repairs without conduits than in repairs with conduits. Conduits therefore facilitated a more complete return of electrophysiological function. Histologic analyses confirmed FN continuity and revealed more organized FN regenerative architecture in conduit-implanted repairs.
  
  
  CONCLUSIONS
  The overall results support enhanced FN regeneration with collagen conduit entubulation.
authors.affiliation: Department of Otolaryngology, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: Harley S
authors.initials: HS
authors.lastname: Dresner
authors.forename: Timothy A
authors.initials: TA
authors.lastname: King
authors.forename: H Brent
authors.initials: HB
authors.lastname: Clark
authors.forename: Steven K
authors.initials: SK
authors.lastname: Juhn
authors.forename: Samuel C
authors.initials: SC
authors.lastname: Levine
mesh_terms: D000818:Animals; D002415:Cats; D003094:Collagen; D004195:Disease Models, Animal; D004576:Electromyography; D005154:Facial Nerve / Q000502:physiology* / Q000601:surgery*; D020220:Facial Nerve Injuries / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D007150:Immunohistochemistry; D008297:Male; D008866:Microsurgery; D009416:Nerve Regeneration / Q000502:physiology*; D010525:Peripheral Nerves
chemical_list: D003094:Collagen