title: Temporal factors in peripheral nerve reconstruction with suture scaffolds: an experimental study in rodents.
abstract: OBJECTIVE
  This study investigated nerve regeneration following nerve repair with longitudinally oriented sutures, with emphasis on timing. Prior work in rodents has shown that suture scaffolds are comparable to nerve grafting when assessments are made at late time points. However, rodents have exceptional regenerative capacity, making it difficult to detect key differences at late time points. This study therefore investigated regeneration across suture scaffolds both at early (4 week) and late (12 week) endpoints.
  
  
  METHODS
  Rodents were randomized to nerve gap, transection and repair, nerve grafting, and suture scaffold groups. Nerve regeneration was evaluated at 4 and 12 weeks. Histomorphometry parameters were evaluated using binary image analysis of toluidine blue-stained nerve cross sections.
  
  
  RESULTS
  Compared to nerve grafts, suture scaffolds were associated with significantly decreased neural density (4208 +/- 3546 vs. 193 +/- 416, fibers/mm;2, p<0.05) and fiber width (1.92 +/- 1.21 vs. 0.75+/- 1.16, microm, p<0.05). At 12 weeks, differences between groups were no longer detectable.
  
  
  CONCLUSIONS
  When evaluated at optimal time points for rodents, suture scaffolds fail to support regeneration comparable to the existing gold standard of nerve grafting. This finding raises significant concerns regarding the clinical application of suture scaffolds.
authors.affiliation: Division of Plastic and Reconstructive Surgery, Department of Surgery, Washington University School of Medicine, Saint Louis, MO 63110, USA.
authors.forename: Jason D
authors.initials: JD
authors.lastname: Keune
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Brenner
authors.forename: Katherine E
authors.initials: KE
authors.lastname: Schwetye
authors.forename: Jeffery W
authors.initials: JW
authors.lastname: Yu
authors.forename: Ida K
authors.initials: IK
authors.lastname: Fox
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Hunter
authors.forename: Susan E
authors.initials: SE
authors.lastname: Mackinnon
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D004195:Disease Models, Animal; D008297:Male; D009412:Nerve Fibers / Q000473:pathology; D009416:Nerve Regeneration / Q000502:physiology*; D011897:Random Allocation; D051381:Rats; D011917:Rats, Inbred Lew; D019651:Plastic Surgery Procedures / Q000379:methods*; D020426:Sciatic Neuropathy / Q000209:etiology / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D013536:Suture Techniques; D013997:Time Factors