title: Photochemical sealing improves outcome following peripheral neurorrhaphy.
abstract: BACKGROUND
  Peripheral nerve transection initiates a complex molecular response in the severed nerve endings, resulting in the release of neurotrophic and neurotropic factors that are central to axonal survival and regeneration. In this study we tested the hypothesis that sealing the neurorrhaphy site from the surrounding environment using a photochemically bonded nerve wrap would optimize the endoneural environment and enhance regeneration and nerve function recovery.
  
  
  METHODS
  Adult rats underwent unilateral sciatic nerve transection and standard epineural nerve repair. The repair site was wrapped with amniotic membrane or autologous vein and then was either sealed using photochemical tissue bonding (PTB) or secured with sutures. Photochemical sealing without a wrap was also carried out. Functional recovery was assessed at 2-wk intervals using walking track analysis and nerve histomorphometry was assessed at 12 wk.
  
  
  RESULTS
  Treating nerves with PTB-sealed amnion significantly improved functional recovery and increased distal axon and fiber diameters and myelin thickness compared to nerves treated with standard neurorrhaphy alone. Direct PTB sealing of the repair site also improved function. Neither amnion secured with sutures nor vein wraps exhibited improved functional or histological recovery compared to standard neurorrhaphy.
  
  
  CONCLUSIONS
  These results suggest that sealing the peripheral nerve repair site with amnion using a photochemical technique may lead to earlier restoration of neural homeostasis and consequent enhanced repair of nerve injury.
authors.affiliation: Plastic Surgery Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA.
authors.forename: Anne C
authors.initials: AC
authors.lastname: O'Neill
authors.forename: Mark A
authors.initials: MA
authors.lastname: Randolph
authors.forename: Kenneth E
authors.initials: KE
authors.lastname: Bujold
authors.forename: Irene E
authors.initials: IE
authors.lastname: Kochevar
authors.forename: Robert W
authors.initials: RW
authors.lastname: Redmond
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Winograd
mesh_terms: D000650:Amnion / Q000502:physiology; D000818:Animals; D001369:Axons / Q000473:pathology / Q000502:physiology; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D008297:Male; D023421:Models, Animal; D009186:Myelin Sheath / Q000502:physiology; D009416:Nerve Regeneration / Q000502:physiology*; D010778:Photochemotherapy / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000502:physiology*; D012584:Sciatic Nerve / Q000473:pathology / Q000502:physiology* / Q000601:surgery*; D013537:Sutures