论文部分内容阅读
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.