title: Identifying a Safe Range of Stimulation Current for Intraoperative Neuromonitoring of the Recurrent Laryngeal Nerve: Results from a Canine Model.
abstract: BACKGROUND
  Intraoperative neuromonitoring (IONM) of the recurrent laryngeal nerve (RLN) has been widely applied during thyroid surgery. However, the safe range of stimulation intensity for IONM remains undetermined.
  
  
  METHODS
  Total thyroidectomies were performed on twenty dogs, and their RLNs were stimulated with a current of 5-20 mA (step-wise in 5 mA increments) for 1 min. The evoked electromyography (EMG) of vocal muscles before and after supramaximal stimulation were recorded and compared. Acute microstructural morphological changes in the RLNs were observed immediately postoperatively under an electron microscope.
  
  
  RESULTS
  The average stimulating threshold for RLNs stimulated with 15 mA and 20 mA showed no significant changes compared to the unstimulated RLNs (15 mA group: 0.320 ± 0.123 mA vs. 0.315 ± 0.097 mA, P = 0.847; 20 mA group: 0.305 ± 0.101 mA vs. 0.300 ± 0.103 mA, P = 0.758). Similar outcomes were shown in average evoked EMG amplitude (15 mA group: 1,026 ± 268 μV vs. 1,021 ± 273 μV, P = 0.834; 20 mA group: 1,162 ± 275 μV vs. 1,200 ± 258 μV, P = 0.148). However, obvious acute microstructural morphological changes were observed in the nerves that were stimulated with 20 mA.
  
  
  CONCLUSIONS
  A stimulation intensity less than 15 mA might be safe for IONM of the RLN.
authors.affiliation: Department of Gastrointestinal Surgery, Surgical Oncology Laboratory, Peking University People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.affiliation: Department of Gastrointestinal Surgery, Surgical Oncology Laboratory, Peking University People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Department of Gastrointestinal Surgery, Surgical Oncology Laboratory, Peking University People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Gastrointestinal Surgery, Surgical Oncology Laboratory, Peking University People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Zhi-Dong
authors.initials: ZD
authors.lastname: Gao
authors.affiliation: Department of Gastrointestinal Surgery, Surgical Oncology Laboratory, Peking University People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Guo
authors.affiliation: Department of Gastrointestinal Surgery, Surgical Oncology Laboratory, Peking University People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Zhan-Long
authors.initials: ZL
authors.lastname: Shen
authors.affiliation: Department of Gastrointestinal Surgery, Surgical Oncology Laboratory, Peking University People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Yang
authors.affiliation: Department of Gastrointestinal Surgery, Surgical Oncology Laboratory, Peking University People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Qi-Wei
authors.initials: QW
authors.lastname: Xie
authors.affiliation: Department of Gastrointestinal Surgery, Surgical Oncology Laboratory, Peking University People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Ying-Jiang
authors.initials: YJ
authors.lastname: Ye
authors.affiliation: Department of Gastrointestinal Surgery, Surgical Oncology Laboratory, Peking University People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Ke-Wei
authors.initials: KW
authors.lastname: Jiang
authors.affiliation: Department of Gastrointestinal Surgery, Surgical Oncology Laboratory, Peking University People's Hospital, Peking University, Beijing 100044, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Wang
mesh_terms: D000818:Animals; D004285:Dogs; D004576:Electromyography; D008297:Male; D016343:Monitoring, Intraoperative / Q000379:methods*; D012009:Recurrent Laryngeal Nerve / Q000503:physiopathology / Q000601:surgery*; D013961:Thyroid Gland / Q000503:physiopathology / Q000601:surgery; D013965:Thyroidectomy / Q000379:methods