术中神经监测对喉上神经外支的保护作用

The Protective Effect of Intraoperative Nerve Monitoring on External Branch of the Superior Laryngeal Nerve

目的评估术中神经监测(intraoperative neuromonitoring,IONM)在甲状腺手术中对喉上神经外支(external branch of the superior laryngeal nerve,EBSLN)的保护作用。方法共133例行甲状腺手术的患者[98例女性,35例男性,年龄(45.6±11.7)岁],随机分成2组。对于组1(n=66,112条神经)的患者,解剖甲状腺上极时不尝试识别EBSLN;对于组2(n=67,115条神经)的患者,手术时使用IONM来识别EBSLN。用术中环甲肌(cricothyroid muscle,CTM)震颤和声带肌电图(electromyography,EMG)信号来评估EBSLN功能。对于所有患者,分别于术前和术后第1,3,6个月行EBSLN声音损伤指数-5(voice impairment index-5,VII-5)评估。观察EBSLN损伤率、IONM对EBSLN的识别率及术后声音的改变情况。结果组1中共有9例(13.4%)患者共10条(8.9%)EBSLN损伤,组2中有1例(1.5%)患者共1条(0.9%)神经损伤,与组1相比,组2的神经损伤率显著降低(例数,P=0.008;EBSLN数,P=0.004)。而且IONM明显提高了组2的肉眼(P <0.001)和功能(P <0.001)识别率。结论甲状腺手术中,使用IONM有助于肉眼和功能识别EBSLN,降低EBSLN的损伤率,从而减少患者术后声音改变,即IONM对于EBSLN有保护作用。

Objective To evaluate the protective effect of intraoperative nerve monitoring(IONM) on external branch of the superior laryngeal nerve(EBSLN) in thyroid surgery. Methods A total of 133 patients undergoing thyroid surgery [98 women, 35 men, the average age(45.6+11.7) years] were randomly divided into two groups. For group 1(n=66, 112 nerves), we did not try to identify EBSLN when dissecting the superior pole of the thyroid gland. For patients in group 2(n=67, 115 nerves), IONM was used to identify EBSLN during the surgery. Cricothyroid muscle(CTM) tremor and vocal cord electromyography(EMG) signal were utilized to evaluate EBSLN function. Voice Impairment Index-5(VII-5) evaluations was performed before and 1, 3, 6 months after the surgery for all patients. The injury rate of EBSLN, the recognition rate of IONM to EBSLN and the postoperative voice change were observed. Results EBSLN injury was detected in 9(13.4%) patients and 10(8.9%) nerves in group 1 and in 1(1.5%) patient and 1(0.9%) nerve in group 2. Compared with group 1, the rate of nerve injury in group 2 was significantly reduced(patients, P=0.008;EBSLNs, P=0.004). Furthermore, IONM contributed significantly to visual(P < 0.001) and functional(P < 0.001) nerve identification in group 2. Conclusion In thyroid surgery, the utilization of IONM can help the visual and functional identification of the EBSLN and reduce the injury rate of EBSLN, thus reducing the postoperative voice change of patients, IONM has a protective effect on EBSLN.