Department of Thyroid and Breast Surgery, Zhongnan Hospital of Wuhan University, 169 Donghu Road, Wuhan, Hubei, People's Republic of China.
Department of Critical Care Medicine, Zhongnan Hospital of Wuhan University, Wuhan, 430071 Hubei Province, People's Republic of China.
Auris Nasus Larynx. 2021 Oct;48(5):942-948. doi: 10.1016/j.anl.2021.01.011. Epub 2021 Jan 13.
To evaluate the contribution of amplitude reduction compared vagal stimulation at the end of thyroid dissection (V2) to the most distal RLN stimulation during thyroidectomy in predicting postoperative vocal cords paralysis (VCP).
Patients with intact preoperative RLN function who underwent monitored thyroidectomy between August 2017 and April 2018 were included. We routinely tested the exposed RLN at the lowest proximal end (R2p signal) and the most distal end near the laryngeal entry point (R2d signal), and then routinely detected the vagal nerve at the horizontal plane of the inferior pole of thyroid with 2mA stimulation current. The cut-off value was calculated with Receiver Operating Characteristic curve. Rates of specificity, sensitivity, negative predictive value, positive predictive value (PPV) for V2/R2d and R2p/R2d were compared.
Percentage reduction of the amplitude of V2/R2d ranged from 34.8% to 76.7%. Twenty-two (1.5%) nerves developed temporary VCP, in which one nerve with VCP showed no significant amplitude reduction at the end of the surgery. There was no permanent or bilateral VCP. Sensitivity, specificity, PPV, NPV, and accuracy for the amplitude reduction of V2/R2d> 60% were 95.5%, 99.8%, 99.9%, 98.2%, respectively, for R2p/R2d were 99.5%, 99.2%, 63.6%, 99.9%, 97.7%, respectively.
Percentage reduction of the amplitude of V2/R2d is a reliable and practical warning criterion for RLN injury. When the amplitude reduction> 60% surgeons should consider the possibility of postoperative VCP and correct some surgical maneuvers.
评估甲状腺解剖结束时的幅度降低（V2）与甲状腺切除术期间 RLN 最远端刺激相比，对预测术后声带麻痹（VCP）的贡献。
纳入 2017 年 8 月至 2018 年 4 月期间接受监测性甲状腺切除术的术前 RLN 功能完整的患者。我们常规测试暴露的 RLN 在最低近端（R2p 信号）和靠近声门入口的最远端（R2d 信号），然后常规在甲状腺下极的水平平面用 2mA 刺激电流检测迷走神经。用受试者工作特征曲线计算截断值。比较 V2/R2d 和 R2p/R2d 的特异性、敏感性、阴性预测值、阳性预测值（PPV）。
V2/R2d 幅度降低的百分比范围为 34.8%至 76.7%。22 根（1.5%）神经发生暂时性 VCP，其中一根 VCP 神经在手术结束时无明显幅度降低。无永久性或双侧 VCP。V2/R2d>60%幅度降低的敏感性、特异性、PPV、NPV 和准确性分别为 95.5%、99.8%、99.9%、98.2%，R2p/R2d 分别为 99.5%、99.2%、63.6%、99.9%、97.7%。
V2/R2d 幅度降低的百分比是 RLN 损伤的可靠且实用的预警标准。当幅度降低>60%时，外科医生应考虑术后 VCP 的可能性，并纠正一些手术操作。
