title: Forced needle advancement during needle-nerve contact in a porcine model: histological outcome.
abstract: BACKGROUND
  In this study, we determined whether needle advancement during needle-nerve contact (forced needle-nerve contact) is associated with a higher risk of nerve injury compared with needle-nerve contact without needle advancement (nonforced needle-nerve contact).
  
  
  METHODS
  In 8 anesthetized pigs, the brachial plexus nerves underwent forced (0.15 Newton) or nonforced (0.0 Newton) needle-nerve contact without nerve penetration. The grade of nerve injury was histologically assessed using an objective score ranging from 0 (no injury) to 4 (severe injury).
  
  
  RESULTS
  Sixty-nine nerves, including controls, were examined. Histology revealed a significant difference between forced and nonforced needle-nerve contact (median [interquartile range] 3 [2-4] vs 2 [1-2]; P = 0.004). Myelin damage and intraneural hematoma occurred only after forced needle-nerve contact.
  
  
  CONCLUSIONS
  The severity of structural nerve injury after needle-nerve contact was directly related to force exposure via needle advancement.
authors.affiliation: Philipps University, Department of Anaesthesiology and Intensive Care Therapy, University Hospital Giessen-Marburg, Campus Marburg, Baldingerstrasse, 35032 Marburg, Germany. steinfeldt@gmx.de
authors.forename: Thorsten
authors.initials: T
authors.lastname: Steinfeldt
authors.forename: Sabine
authors.initials: S
authors.lastname: Poeschl
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Nimphius
authors.forename: Juergen
authors.initials: J
authors.lastname: Graf
authors.forename: Martin
authors.initials: M
authors.lastname: Zoremba
authors.forename: Hans-Helge
authors.initials: HH
authors.lastname: Mueller
authors.forename: Hinnerk
authors.initials: H
authors.lastname: Wulf
authors.forename: Frank
authors.initials: F
authors.lastname: Dette
mesh_terms: D000765:Anesthesia, Conduction / Q000295:instrumentation*; D000818:Animals; D001917:Brachial Plexus / Q000033:anatomy & histology; D006406:Hematoma / Q000473:pathology; D007150:Immunohistochemistry; D007249:Inflammation / Q000473:pathology; D009186:Myelin Sheath / Q000473:pathology; D009339:Needles; D059348:Peripheral Nerve Injuries; D010525:Peripheral Nerves / Q000033:anatomy & histology / Q000473:pathology; D013552:Swine