title: Laryngeal abductor reinnervation with a phrenic nerve transfer after a 9-month delay.
abstract: BACKGROUND
  Successful restoration of laryngeal abductor function, using the phrenic nerve, has been described in the cat model in the acute phase. However, in clinical practice there is usually a considerable delay between injury to the RLN and presentation for treatment. Delayed reinnervation therefore would be more suitable in clinical practice.
  
  
  OBJECTIVE
  To test the feasibility of delayed selective abductor reinnervation following transection of the recurrent laryngeal nerve (RLN).
  
  
  METHODS
  In 12 cats, the right RLN was severed. Nine months later, the phrenic nerve was anastomosed to the distal RLN stump with all its branches directed toward the posterior cricoarytenoid muscle. For 10 weeks after the reconstruction, electromyography and videolaryngoscopy were performed weekly. Finally, histological analysis of the RLN was performed.
  
  
  RESULTS
  Evaluation was possible in 11 cats. Reinnervation of the right posterior cricoarytenoid muscle with the phrenic nerve occurred in 10 cats following nerve anastomosis, but results of videolaryngoscopy showed adequate to good abduction in only 4 cats. The main limiting factor was reduced mobility of the cricoarytenoid joint. Evidence of spontaneous subclinical reinnervation after the delay was observed in 7 cats but apparently did not impede the surgical reinnervation.
  
  
  CONCLUSIONS
  Delayed selective laryngeal abductor reinnervation was feasible, but function recovery was less successful than if performed immediately. Future investigations should concentrate on early determinants of spontaneous restoration of function to allow early selection of patients who are eligible for reinnervation surgery.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University Hospital, Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: J T
authors.initials: JT
authors.lastname: van Lith-Bijl
authors.forename: R J
authors.initials: RJ
authors.lastname: Stolk
authors.forename: J A
authors.initials: JA
authors.lastname: Tonnaer
authors.forename: C
authors.initials: C
authors.lastname: Groenhout
authors.forename: P N
authors.initials: PN
authors.lastname: Konings
authors.forename: H F
authors.initials: HF
authors.lastname: Mahieu
mesh_terms: D000714:Anastomosis, Surgical; D000818:Animals; D002415:Cats; D004576:Electromyography; D005240:Feasibility Studies; D005260:Female; D007821:Laryngeal Muscles / Q000294:innervation*; D007828:Laryngoscopy; D009121:Muscle Denervation; D009416:Nerve Regeneration / Q000502:physiology*; D016067:Nerve Transfer / Q000379:methods*; D010791:Phrenic Nerve / Q000502:physiology / Q000637:transplantation*; D012123:Pulmonary Ventilation / Q000502:physiology; D012009:Recurrent Laryngeal Nerve / Q000502:physiology / Q000601:surgery; D014741:Video Recording; D014828:Vocalization, Animal / Q000502:physiology