Background： lntraoperative neuromonitoring （IONM） of the recunent laryngeal nerve （RLN） has been widely applied during thyroid surgery. However, the sale range of stimulation intensity for IONM remains undetermin...Background： lntraoperative neuromonitoring （IONM） of the recunent laryngeal nerve （RLN） has been widely applied during thyroid surgery. However, the sale 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 p.V xs. 1,021 ± 273 p.V, P = 0.834; 20 mA group： 1,162 ± 275 μV vs. 1,200 ± 258μV, 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.展开更多
文摘Background： lntraoperative neuromonitoring （IONM） of the recunent laryngeal nerve （RLN） has been widely applied during thyroid surgery. However, the sale 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 p.V xs. 1,021 ± 273 p.V, P = 0.834; 20 mA group： 1,162 ± 275 μV vs. 1,200 ± 258μV, 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.
