title: Intraoperative neuromonitoring of the external branch of the superior laryngeal nerve during robotic thyroid surgery: a preliminary prospective study.
abstract: OBJECTIVE
  The aim of this study was to evaluate the feasibility of monitoring external branch of the superior laryngeal nerve (EBSLN) during robotic thyroid surgery.
  
  
  METHODS
  A total of 10 patients undergoing bilateral axillo-breast approach (BABA) robotic thyroid surgery were enrolled. The nerve integrity monitor (NIM Response 2.0 System) was used for EBSLN monitoring. We performed voice assessments preoperatively and at 1 and 3 months postoperatively using Voice Handicap Index-10 (VHI-10), maximal phonation time (MPT), phonation efficient index (PEI), and laryngeal electromyography (EMG).
  
  
  RESULTS
  A total of 19 EBSLNs were at risk and 14 EBSLNs (73.7%) were identified using neuromonitoring. VHI-10 showed a change of voice over time (0.1 vs. 3.6 vs. 1.3); however, this was not statistically significant. VHI-10 scores normalized at 3 months postoperatively compared to the preoperative scores. MPT (a) (16.0 vs. 15.6 vs. 15.4), and MPT (e) (20.1 vs. 15.4 vs. 18.5) showed no significant differences preoperatively compared to the values obtained 1 and 3 months postoperatively. There was a significant change of PEI over time (4.8 vs. 1.1 vs. 4.6) (P = 0.036); however, the values normalized at 3 months postoperatively. Laryngeal EMG results showed 4 cases (21.2%) of neuropathy of EBSLNs at 1 month postoperatively, and electrodiagnostic studies revealed nearly complete recovery of the function of EBSLNs in 4 patients at 3 months postoperatively.
  
  
  CONCLUSIONS
  It is suggested that neuromonitoring of EBSLNs during BABA robotic thyroid surgery is feasible and might be helpful to preserve voice quality.
authors.affiliation: Department of Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Su-Jin
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyu Eun
authors.initials: KE
authors.lastname: Lee
authors.affiliation: Department of Rehabilitation Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Byung-Mo
authors.initials: BM
authors.lastname: Oh
authors.affiliation: Department of Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Eun Mee
authors.initials: EM
authors.lastname: Oh
authors.affiliation: Department of Surgery, Inje University Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
authors.forename: Dong Sik
authors.initials: DS
authors.lastname: Bae
authors.affiliation: Department of Surgery, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: June Young
authors.initials: JY
authors.lastname: Choi
authors.affiliation: Department of Department of Occupational and Environmental Medicine, Seoul St. Mary's Hospital, The Catholic University College of Medicine, Seoul, Korea.
authors.forename: Jun Pyo
authors.initials: JP
authors.lastname: Myong
authors.affiliation: Department of Surgery, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Yeo-Kyu
authors.initials: YK
authors.lastname: Youn
keywords: Intraoperative neurophysiological monitoring; Laryngeal nerves; Robotic surgical procedures; Thyroidectomy