title: Use of cold-preserved allografts seeded with autologous Schwann cells in the treatment of a long-gap peripheral nerve injury.
abstract: BACKGROUND
  Limitations in autogenous tissue have inspired the study of alternative materials for repair of complex peripheral nerve injuries. Cadaveric allografts are one potential reconstructive material, but their use requires systemic immunosuppression. Cold preservation (> or =7 weeks) renders allografts devoid of antigens, but these acellular substrates generally fail in supporting regeneration beyond 3 cm. In this study, the authors evaluated the reconstruction of extensive nonhuman primate peripheral nerve defects using 7-week cold-preserved allografts repopulated with cultured autologous Schwann cells.
  
  
  METHODS
  Ten outbred Macaca fascicularis primates were paired based on maximal genetic disparity as measured by similarity index assay. A total of 14 ulnar nerve defects measuring 6 cm were successfully reconstructed using autografts (n = 5), fresh allografts (n = 2), cold-preserved allografts (n = 3), or cold-preserved allografts seeded with autogenous Schwann cells (n = 4). Recipient immunoreactivity was evaluated by means of enzyme-linked immunosorbent spot assay, and nerves were harvested at 6 months for histologic and histomorphometric analysis.
  
  
  RESULTS
  Cytokine production in response to cold-preserved allografts and cold-preserved allografts seeded with autologous Schwann cells was similar to that observed for autografts. Schwann cell-repopulated cold-preserved grafts demonstrated significantly enhanced fiber counts, nerve density, and percentage nerve (p < 0.05) compared with unseeded cold-preserved grafts at 6 months after reconstruction.
  
  
  CONCLUSIONS
  Cold-preserved allografts seeded with autologous Schwann cells were well-tolerated in unrelated recipients and supported significant regeneration across 6-cm peripheral nerve defects. Use of cold-preserved allogeneic nerve tissue supplemented with autogenous Schwann cells poses a potentially safe and effective alternative to the use of autologous tissue in the reconstruction of extensive nerve injuries.
authors.affiliation: St. Louis, Mo. From the Division of Plastic and Reconstructive Surgery, Department of Surgery, and Department of Otolaryngology-Head and Neck Surgery, Washington University School of Medicine.
authors.forename: Jason R
authors.initials: JR
authors.lastname: Hess
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Brenner
authors.forename: Ida K
authors.initials: IK
authors.lastname: Fox
authors.forename: Chris M
authors.initials: CM
authors.lastname: Nichols
authors.forename: Terence M
authors.initials: TM
authors.lastname: Myckatyn
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Hunter
authors.forename: Susan R
authors.initials: SR
authors.lastname: Rickman
authors.forename: Susan E
authors.initials: SE
authors.lastname: Mackinnon
mesh_terms: D000818:Animals; D015925:Cryopreservation; D005260:Female; D008252:Macaca fascicularis; D059348:Peripheral Nerve Injuries; D010525:Peripheral Nerves / Q000601:surgery*; D012583:Schwann Cells / Q000637:transplantation*; D014459:Ulnar Nerve / Q000033:anatomy & histology / Q000637:transplantation*