title: Superior laryngeal nerve block: an anatomical study comparing two techniques.
abstract: OBJECTIVE
  To determine whether an anterior approach is as successful as the conventional posterior approach to superior laryngeal nerve block.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  University anatomy laboratory.
  
  
  METHODS
  20 formalin-fixed adult human cadavers.
  
  
  METHODS
  Simulated superior laryngeal nerve blocks were performed by a single operator using 3 mL of 0.01% analine blue dye with a 23-gauge Quincke tip needle. Two different landmark techniques were used on each undissected cadaver: 1) the conventional posterior approach using the hyoid bone as a palpable landmark, with injection at the posterior third of the thyrohyoid membrane; and 2) the anterior approach, using the anterior thyroid notch of the thyroid cartilage, with injection at the anterior third of the thyrohyoid membrane. The spread of analine dye was observed. An injection was deemed successful if the entire paraglottic space was stained or the superior laryngeal nerve stained as it entered the paraglottic space.
  
  
  RESULTS
  Both techniques were equally successful after 40 injections.
  
  
  CONCLUSIONS
  There was no significant difference in success in staining the superior laryngeal nerve in human cadavers between the conventional posterior approach and an anterior approach.
authors.affiliation: Senior Lecturer, Department of Surgery, University of Melbourne, Level 6 Centre for Medical Research, Royal Parade, Parkville, VIC 3050, Australia; Consultant Anaesthetist, Department of Anaesthesia and Pain Management, Royal Melbourne Hospital, Corner Royal Parade and Grattan Street, Parkville, Victoria, 3050, Australia. Electronic address: dcanty@unimelb.edu.au.
authors.forename: David Jeffrey
authors.initials: DJ
authors.lastname: Canty
authors.affiliation: Consultant Anaesthetist, Epworth Hospital, 89 Bridge Road, Richmond, VIC 3121, Australia.
authors.forename: Laurence
authors.initials: L
authors.lastname: Poon
mesh_terms: D000328:Adult; D002102:Cadaver; D006801:Humans; D006928:Hyoid Bone / Q000033:anatomy & histology; D007823:Laryngeal Nerves / Q000033:anatomy & histology*; D009407:Nerve Block / Q000379:methods*; D011446:Prospective Studies; D013957:Thyroid Cartilage / Q000033:anatomy & histology
keywords: Anesthesia local; Laryngeal nerves; Nerve block; Patient simulation; Simulation; Superior laryngeal nerve