To compare the clinical effects of continuous intraoperative neuromonitoring (c-ionm) and intermittent intraoperative neuromonitoring (i-ionm) in endoscopic assisted thyroid surgery.

Data of 59 patients undergoing endoscopic assisted thyroid surgery from May 2016 to December 2018 were retrospectively analyzed, and they were divided into the c-ionm group and the i-ionm group according to different intraoperative neuromonitoring methods. SPSS 21.0 statistical software was used for analysis. The function evaluation of vagus nerve and recurrent laryngeal nerve was expressed by(±s), and independent t test was performed. χ² test was performed for recurrent laryngeal nerve injury. P<0.05 indicated the difference was statistically significant.

There was no significant difference in intraoperative nerve monitoring time between the two groups (P>0.05). Among the 59 patients, 86 recurrent laryngeal nerves were dissected and exposed, among which 11 showed a decrease of EMG amplitude by >50% during the operation, and gradually recovered to more than 70% of the initial R1 signal level within 10 min after the operation was stopped, with an average recovery time of (6.7±2.5) min. There was no significant difference between the two groups in the injury and recovery of recurrent laryngeal nerves during the operation (P>0.05). There was no significant difference in EMG amplitude and latency between the two groups compared with the APS electrode stimulation at the beginning (P>0.05). Under the light microscope, the structure of the vagus nerve and recurrent laryngeal nerve in the two groups was normal, the fiber cells were complete, and there was no neurobundle edema and neurovascular injury.

The efficacy of c-ionm and i-ionm in endoscopic thyroid surgery is similar in reducing the injury of vagus and recurrent laryngeal nerve. The two neuromonitoring techniques have no effect on the neurological function of patients, and both are safe and reliable.