title: Influence of suture on peripheral nerve regeneration and collagen production at the site of neurorrhaphy: an experimental study.
abstract: BACKGROUND
  Restoration of nerve continuity and effective maintenance of coaptation are considered fundamental principles of end-to-end peripheral nerve repair.
  
  
  OBJECTIVE
  To evaluate the influence of the number of stitches on axonal regeneration and collagen production after neurorrhaphy.
  
  
  METHODS
  Thirty male Wistar rats were equally divided into 3 groups and were all operated on with the right sciatic nerve exposed. In 2 groups, the nerve was sectioned and repaired by means of 3 (group B) or 6 (group C) epineurium sutures with 10-0 monofilament nylon. One group (group A) was used as a control. Each animal from groups B and C underwent electrophysiological evaluation with motor action potential recordings before nerve section and again at an 8-week interval after neurorrhaphy. Nerve biopsy specimens were used for histomorphometric assessment of axonal regeneration and quantification of collagen at the repair site.
  
  
  RESULTS
  Animals from group C had significantly lower motor action potential conduction velocities compared with control animals (P=.02), and no significant difference was seen between groups B and C. Parameters obtained from morphometric evaluation were not significantly different between these 2 groups. Type I collagen and III collagen in the epineurium were significantly higher in group C than in either the control group (P=.001 and P=.003) or group B (P=.01 and P=.02). No differences were identified for collagen I and III in the endoneurium.
  
  
  CONCLUSIONS
  Using 6 sutures for nerve repair is associated with worse electrophysiological outcomes and higher amounts of type I and III collagen in the epineurium compared with control. Neurorraphy with 6 stitches is also related to a significant increase in epineurium collagen I and III compared with 3-stitch neurorraphy.
authors.affiliation: Peripheral Nerve Surgery Unit, Department of Neurosurgery, São Paulo University School of Medicine and Hospital do Servidor Público do Estado, São Paulo, Brazil. robar@ig.com.br
authors.forename: Roberto Sergio
authors.initials: RS
authors.lastname: Martins
authors.forename: Walcy Rosolio
authors.initials: WR
authors.lastname: Teodoro
authors.forename: Hougelle
authors.initials: H
authors.lastname: Simplicio
authors.forename: Vera Luiza
authors.initials: VL
authors.lastname: Capellozi
authors.forename: Mario Gilberto
authors.initials: MG
authors.lastname: Siqueira
authors.forename: Natalino Hajime
authors.initials: NH
authors.lastname: Yoshinari
authors.forename: José Pindaro
authors.initials: JP
authors.lastname: Pereira
authors.forename: Manoel Jacobsen
authors.initials: MJ
authors.lastname: Teixeira
mesh_terms: D000818:Animals; D003094:Collagen / Q000096:biosynthesis*; D048091:Guided Tissue Regeneration / Q000295:instrumentation*; D008297:Male; D009416:Nerve Regeneration / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D020426:Sciatic Neuropathy / Q000503:physiopathology* / Q000601:surgery*; D013537:Sutures; D054457:Tissue Scaffolds; D016896:Treatment Outcome
chemical_list: D003094:Collagen