title: Light-Activated Sealing of Acellular Nerve Allografts following Nerve Gap Injury.
abstract: Introduction Photochemical tissue bonding (PTB) uses visible light to create sutureless, watertight bonds between two apposed tissue surfaces stained with photoactive dye. In phase 1 of this two-phase study, nerve gaps repaired with bonded isografts were superior to sutured isografts. When autograft demand exceeds supply, acellular nerve allograft (ANA) is an alternative although outcomes are typically inferior. This study assesses the efficacy of PTB when used with ANA. Methods Overall 20 male Lewis rats had 15-mm left sciatic nerve gaps repaired using ANA. ANAs were secured using epineurial suture (group 1) or PTB (group 2). Outcomes were assessed using sciatic function index (SFI), gastrocnemius muscle mass retention, and nerve histomorphometry. Historical controls from phase 1 were used to compare the performance of ANA with isograft. Statistical analysis was performed using analysis of variance and Bonferroni all-pairs comparison. Results All ANAs had signs of successful regeneration. Mean values for SFI, muscle mass retention, nerve fiber diameter, axon diameter, and myelin thickness were not significantly different between ANA + suture and ANA + PTB. On comparative analysis, ANA + suture performed significantly worse than isograft + suture from phase 1. However, ANA + PTB was statistically comparable to isograft + suture, the current standard of care. Conclusion Previously reported advantages of PTB versus suture appear to be reduced when applied to ANA. The lack of Schwann cells and neurotrophic factors may be responsible. PTB may improve ANA performance to an extent, where they are equivalent to autograft. This may have important clinical implications when injuries preclude the use of autograft.
authors.affiliation: Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Neil G
authors.initials: NG
authors.lastname: Fairbairn
authors.affiliation: Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Joanna
authors.initials: J
authors.lastname: Ng-Glazier
authors.affiliation: Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Meppelink
authors.affiliation: Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Randolph
authors.affiliation: Plastic Surgery Service, Walter Reed National Military Medical Center, Bethesda, Maryland.
authors.forename: Ian L
authors.initials: IL
authors.lastname: Valerio
authors.affiliation: Department of Orthopaedics, Walter Reed National Military Medical Center, Bethesda, Maryland.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Fleming
authors.affiliation: Wellman Centre for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Irene E
authors.initials: IE
authors.lastname: Kochevar
authors.affiliation: Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Winograd
authors.affiliation: Wellman Centre for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Redmond
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005456:Fluorescent Dyes; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation; D009416:Nerve Regeneration / Q000502:physiology* / Q000528:radiation effects*; D055668:Photochemical Processes; D051381:Rats; D011917:Rats, Inbred Lew; D020127:Recovery of Function; D012584:Sciatic Nerve / Q000293:injuries* / Q000473:pathology / Q000528:radiation effects / Q000637:transplantation*; D058106:Wound Closure Techniques; D014945:Wound Healing / Q000502:physiology / Q000528:radiation effects
chemical_list: D005456:Fluorescent Dyes