title: Light-Activated Sealing of Nerve Graft Coaptation Sites Improves Outcome following Large Gap Peripheral Nerve Injury.
abstract: BACKGROUND
  Nerve repair using photochemically bonded human amnion nerve wraps can result in superior outcomes in comparison with standard suture. When applied to nerve grafts, efficacy has been limited by proteolytic degradation of bonded amnion during extended periods of recovery. Chemical cross-linking of amnion before bonding may improve wrap durability and efficacy.
  
  
  METHODS
  Three nerve wraps (amnion, cross-linked amnion, and cross-linked swine intestinal submucosa) and three fixation methods (suture, fibrin glue, and photochemical bonding) were investigated. One hundred ten Lewis rats had 15-mm left sciatic nerve gaps repaired with isografts. Nine groups (n = 10) had isografts secured by one of the aforementioned wrap/fixation combinations. Positive and negative control groups (n = 10) were repaired with graft and suture and no repair, respectively. Outcomes were assessed using sciatic function index, muscle mass retention, and histomorphometry. Statistical analysis was performed using analysis of variance and the post hoc Bonferroni test (p < 0.05).
  
  
  RESULTS
  Cross-linking improved amnion durability. Photochemically bonded cross-linked amnion recovered the greatest sciatic function index, although this was not significant in comparison with graft and suture. Photochemically bonded cross-linked amnion recovered significantly greater muscle mass (67.3 ± 4.4 percent versus 60.0 ± 5.2 percent; p = 0.02), fiber diameter, axon diameter, and myelin thickness (6.87 ± 2.23 μm versus 5.47 ± 1.70 μm; 4.51 ± 1.83 μm versus 3.50 ± 1.44 μm; and 2.35 ± 0.64 μm versus 1.96 ± 0.47 μm, respectively) in comparison with graft and suture.
  
  
  CONCLUSIONS
  Light-activated sealing of cross-linked human amnion results in superior outcomes when compared with conventional suture.
authors.affiliation: Boston, Mass.; and Bethesda, Md. From the Division of Plastic Surgery and the Wellman Center for Photomedicine, Massachusetts General Hospital; and the Plastic Surgery Service and the Department of Orthopedics, Walter Reed National Military Medical Center.
authors.forename: Neil G
authors.initials: NG
authors.lastname: Fairbairn
authors.forename: Joanna
authors.initials: J
authors.lastname: Ng-Glazier
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Meppelink
authors.forename: Mark A
authors.initials: MA
authors.lastname: Randolph
authors.forename: Ian L
authors.initials: IL
authors.lastname: Valerio
authors.forename: Mark E
authors.initials: ME
authors.lastname: Fleming
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Winograd
authors.forename: Robert W
authors.initials: RW
authors.lastname: Redmond
mesh_terms: D000650:Amnion; D000818:Animals; D015718:Fibrin Tissue Adhesive; D005456:Fluorescent Dyes / Q000008:administration & dosage; D006801:Humans; D007413:Intestinal Mucosa; D053685:Laser Therapy / Q000379:methods*; D008297:Male; D009416:Nerve Regeneration; D019635:Neurosurgical Procedures / Q000379:methods*; D059348:Peripheral Nerve Injuries / Q000601:surgery*; D011897:Random Allocation; D051381:Rats; D011917:Rats, Inbred Lew; D012395:Rose Bengal / Q000008:administration & dosage; D012584:Sciatic Nerve / Q000293:injuries* / Q000502:physiology / Q000637:transplantation*; D013537:Sutures; D013552:Swine; D014014:Tissue Adhesives; D058106:Wound Closure Techniques
chemical_list: D015718:Fibrin Tissue Adhesive; D005456:Fluorescent Dyes; D014014:Tissue Adhesives; D012395:Rose Bengal