title: Neuromonitoring of the external branch of the superior laryngeal nerve during minimally invasive thyroid surgery under local anesthesia: a prospective study of 10 patients.
abstract: OBJECTIVE
  Avoiding alterations of the voice is a challenge in thyroid surgery. Identification and preservation of the external branch of the superior laryngeal nerve (EBSLN) is paramount for normal vocal function preservation after thyroidectomy. Conventional nerve monitoring requires a general anesthesia and placement of a special endotracheal tube equipped with electrodes to evoke the laryngeal nerves. This study aims to assess feasibility and efficacy of a novel technique of neuromonitoring of the EBSLN under local anesthesia during minimally invasive thyroidectomy. STUDY DESIGN;
  
  
  METHODS
  This study is a prospective trial to evaluate the efficacy of nerve monitoring of the EBSLN during minimally invasive thyroidectomy under local anesthesia. Patient self-assessment of changes in perceived voice severity prior to and 3 weeks after surgery was assessed with the Voice Handicap Index-10 (VHI-10).
  
  
  RESULTS
  Thyroidectomy was successfully completed under local anesthesia in all cases. The recurrent laryngeal nerve(s) was identified and preserved in each patient as demonstrated by normal perioperative transnasal flexible laryngoscopy. A total of 15 EBSLNs were at risk, but only 8 EBSLNs (53%) were definitively identified. Neuromonitoring demonstrated preservation of the EBSLN in 100% of cases. The analysis of the results of the VHI-10 questionnaire before and 3 weeks after surgery indicated no significant change in patients' perception of voice severity.
  
  
  CONCLUSIONS
  Monitoring of the EBSLN during thyroidectomy under local anesthesia is a feasible alternative to conventional nerve monitoring under general anesthesia. This technique may be useful for the preservation of voice quality during a minimally invasive thyroidectomy under local anesthesia.
authors.affiliation: Department of Surgery, Division of Gastrointestinal and Endocrine Surgery, Columbia University, New York, New York 10032, USA. wbi2102@columbia.edu
authors.forename: William B
authors.initials: WB
authors.lastname: Inabnet
authors.forename: Thomas
authors.initials: T
authors.lastname: Murry
authors.forename: Shamly
authors.initials: S
authors.lastname: Dhiman
authors.forename: Jonathan
authors.initials: J
authors.lastname: Aviv
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Lifante
mesh_terms: D000328:Adult; D000772:Anesthesia, Local / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007823:Laryngeal Nerves / Q000503:physiopathology*; D007828:Laryngoscopy / Q000379:methods*; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D011446:Prospective Studies; D013959:Thyroid Diseases / Q000601:surgery*; D013965:Thyroidectomy / Q000379:methods*; D016896:Treatment Outcome; D014827:Vocal Cords / Q000294:innervation* / Q000503:physiopathology; D014833:Voice Quality / Q000502:physiology