title: Neuroma formation in a rat median nerve model: influence of distal stump and muscular coating.
abstract: BACKGROUND
  The purpose of this study was to investigate neuroma formation in a rat median nerve model.
  
  
  METHODS
  In three groups, the median nerve was exposed and a gap was created. In the first group, a short gap of 1 cm (n = 12) was created; in the second, a long gap of 2 cm (n = 12) was created in the nerve. Another group was used to analyze the development of neuroma formation when the proximal stump was buried in adjacent muscle with an additional gap of 2 cm (n = 12). The use of different lengths should allow one to gain information about dilution effects of distal stump factors that may contribute to neuroma formation. Nine months later, specimens were gathered and histologically analyzed. The cross-sectional areas of neuromas were measured and the neural/connective tissue ratios were estimated.
  
  
  RESULTS
  The cross-sectional areas demonstrated that neuroma formation was significantly higher in the short-gap group than in the long-gap group, and smallest in the muscle-covered group. The percentage of neural tissue was highest in the muscle-covered and long-gap groups and lowest in the short-gap group.
  
  
  CONCLUSIONS
  These results demonstrate an association between neuroma formation and distal stump distance. This observation may be explained by the factors originating from the distal stump that were blocked when the proximal nerve stump was completely buried in the muscle. For clinical application, the authors recommend not only burying the proximal stump in a muscle but also surgically augmenting the gap between the proximal and distal stumps.
authors.affiliation: Klinik für Plastische, Hand, Rekonstruktive, und Verbrennungschirurgie, Universität Tübingen, BG-Unfallklinik, Tübingen, Germany. nsinis@bgu-tuebingen.de
authors.forename: Nektarios
authors.initials: N
authors.lastname: Sinis
authors.forename: Max
authors.initials: M
authors.lastname: Haerle
authors.forename: Stephan Thomas
authors.initials: ST
authors.lastname: Becker
authors.forename: Caterina
authors.initials: C
authors.lastname: Schulte-Eversum
authors.forename: Reinhard
authors.initials: R
authors.lastname: Vonthein
authors.forename: Harald
authors.initials: H
authors.lastname: Rösner
authors.forename: Hans-Eberhard
authors.initials: HE
authors.lastname: Schaller
mesh_terms: D000818:Animals; D008475:Median Nerve / Q000293:injuries / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D018482:Muscle, Skeletal / Q000601:surgery; D009463:Neuroma / Q000473:pathology / Q000503:physiopathology* / Q000517:prevention & control; D010524:Peripheral Nervous System Neoplasms / Q000473:pathology / Q000503:physiopathology* / Q000517:prevention & control; D051381:Rats; D011917:Rats, Inbred Lew