Snyder Samuel K, Hendricks John C
Department of Surgery, Scott and White Memorial Hospital and Clinic, Temple, TX, USA.
Surgery. 2005 Dec;138(6):1183-91; discussion 1191-2. doi: 10.1016/j.surg.2005.08.027.
Electrode-imbedded endotracheal tubes allow continuous intraoperative assessment of vocal cord function when connected to an electromyographic (EMG) response monitor. Whether this device enhances or hinders the identification and preservation of the recurrent laryngeal nerve (RLN) is unclear.
The utility of continuous intraoperative neurophysiology testing (INT) of RLNs was evaluated prospectively in 100 patients undergoing 103 thyroid or parathyroid operations, involving 185 RLNs. The initial experience with 93 RLNs was compared with the subsequent 92 RLNs.
Overall, 97.8% of RLNs were identified intraoperatively: 1.6% visually only, 2.2% nerve stimulator only, and 94% both. There was 1 transected RLN (1.1%) in each study group. The EMG monitor could not alert the surgeon to prevent these injuries. Overall, there were 14 instances of nonfunction of visually intact RLNs (7.6%), at some point during the operation and 4 resulting in temporary paralysis (2.2%). There were 8 instances of altered RLN function (4.3%) with no altered vocal cord function postoperatively. The nerve stimulator aided dissection of the RLN in 17 instances (9.2%). There were 7 episodes (3.8%) of equipment dysfunction that hampered surgical dissection. Between study groups there was significantly increased use of the nerve stimulator to first identify the location of the RLN before visual confirmation: 4 of 93, initial group versus 25 of 92, latter group (P < .001).
INT aids the anatomic identification of the RLN only when a positive EMG response occurs. A negative EMG response can indicate a non-nerve structure, altered function of the RLN, or equipment setup malfunction. INT cannot necessarily prevent RLN transection.
嵌入电极的气管内导管在连接肌电图（EMG）反应监测仪时，可在术中持续评估声带功能。该设备是增强还是阻碍喉返神经（RLN）的识别和保护尚不清楚。
前瞻性评估了100例接受103例甲状腺或甲状旁腺手术（涉及185条RLN）患者术中对RLN进行连续神经生理学测试（INT）的效用。将最初93条RLN的经验与随后92条RLN的经验进行了比较。
总体而言，97.8%的RLN在术中被识别：仅通过视觉识别的占1.6%，仅通过神经刺激器识别的占2.2%，两者均识别的占94%。每个研究组均有1条RLN被横断（1.1%）。肌电图监测仪无法提醒外科医生预防这些损伤。总体而言，在手术过程中的某个时间点，有14例视觉上完整的RLN无功能（7.6%），4例导致暂时性麻痹（2.2%）。有8例RLN功能改变（4.3%），术后声带功能未改变。神经刺激器在17例（9.2%）中辅助了RLN的解剖。有7次（3.8%）设备功能障碍妨碍了手术解剖。在研究组之间，在视觉确认之前使用神经刺激器首先识别RLN位置的情况显著增加：初始组93条中有4条，后一组92条中有25条（P<0.001）。
仅当出现阳性肌电图反应时，INT有助于RLN的解剖识别。阴性肌电图反应可能表明是非神经结构、RLN功能改变或设备设置故障。INT不一定能预防RLN横断。
