Continuous intraoperative neuromonitoring in thyroid surgery: Safety analysis of 400 consecutive electrode probe placements with standardized procedures

BACKGROUND: Continuous intraoperative neuromonitoring (C-IONM) is a new technology and it is appropriate to analyze its safety. METHODS: C-IONM was performed according to a standardized technique to control any adverse events and electrode positioning issues. RESULTS: Four hundred vagal nerve dissections were analyzed considering vagal nerve diameter, mean time effort for C-IONM probe positioning, and electrode dislocation rate. A significant superior dislocation rate in case of: (a) when a 3 mm automatic periodic stimulating (APS) electrode size was used in a vagal nerve diameter <2 mm; (b) anterior access; and (c) vagal nerve A subtype in relation (p < .05). No related additional local or systemic morbidity was registered in this series. There was a statistically significant positive relationship between increased diameter of vagal nerve and increased electromyography (EMG) amplitude (p = .03). There was also a significant increase of amplitude between initial and final vagal nerve stimulation in uneventful cases (p = .02). CONCLUSION: We analyzed the technical issues to achieve improved vagal nerve critical view of safety dissection, stimulation, and C-IONM probe placement.