title: Use of a Y-tube conduit after facial nerve injury reduces collateral axonal branching at the lesion site but neither reduces polyinnervation of motor endplates nor improves functional recovery.
abstract: BACKGROUND
  Despite increased understanding of peripheral nerve regeneration, functional recovery after surgical repair remains disappointing. A major contributing factor is the extensive collateral branching at the lesion site, which leads to inaccurate axonal navigation and aberrant reinnervation of targets.
  
  
  OBJECTIVE
  To determine whether the Y tube reconstruction improved axonal regrowth and whether this was associated with improved function.
  
  
  METHODS
  We used a Y-tube conduit with the aim of improving navigation of regenerating axons after facial nerve transection in rats.
  
  
  RESULTS
  Retrograde labeling from the zygomatic and buccal branches showed a halving in the number of double-labeled facial motor neurons (15% vs 8%; P < .05) after Y tube reconstruction compared with facial-facial anastomosis coaptation. However, in both surgical groups, the proportion of polyinnervated motor endplates was similar (≈ 30%; P > .05), and video-based motion analysis of whisking revealed similarly poor function.
  
  
  CONCLUSIONS
  Although Y-tube reconstruction decreases axonal branching at the lesion site and improves axonal navigation compared with facial-facial anastomosis coaptation, it fails to promote monoinnervation of motor endplates and confers no functional benefit.
authors.affiliation: Department of Anatomy, Akdeniz University Faculty of Medicine, Antalya, Turkey.
authors.forename: Arzu
authors.initials: A
authors.lastname: Hizay
authors.forename: Umut
authors.initials: U
authors.lastname: Ozsoy
authors.forename: Bahadir Murat
authors.initials: BM
authors.lastname: Demirel
authors.forename: Ozlem
authors.initials: O
authors.lastname: Ozsoy
authors.forename: Srebrina K
authors.initials: SK
authors.lastname: Angelova
authors.forename: Janina
authors.initials: J
authors.lastname: Ankerne
authors.forename: Sureyya Bilmen
authors.initials: SB
authors.lastname: Sarikcioglu
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Dunlop
authors.forename: Doychin N
authors.initials: DN
authors.lastname: Angelov
authors.forename: Levent
authors.initials: L
authors.lastname: Sarikcioglu
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000637:transplantation; D001369:Axons / Q000473:pathology*; D019771:Axotomy; D020220:Facial Nerve Injuries / Q000473:pathology / Q000601:surgery*; D005260:Female; D009045:Motor Endplate / Q000502:physiology; D009416:Nerve Regeneration; D019635:Neurosurgical Procedures / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function