Hermann Michael, Hellebart Christa, Freissmuth Michael
Department of Surgery, Kaiserin-Elisabeth-Spital, University of Vienna, Vienna, Austria.
Ann Surg. 2004 Jul;240(1):9-17. doi: 10.1097/01.sla.0000132260.34503.02.
We evaluated the ability of neuromonitoring to predict postoperative outcome in patients undergoing thyroid surgery for different indications.
Neuromonitoring has been advocated to reduce the risk of vocal cord palsy and to predict postoperative vocal cord function.
Three hundred twenty-eight patients (502 nerves at risk) were studied prospectively at a single center. Neuromonitoring was performed with the Neurosign 100 device by transligamental placement of the recording electrode into the vocalis muscles. Cumulative distribution of stimulation thresholds was determined by stepwise decreases in current (1 mA to 0.05 mA) for both the vagus and the recurrent nerve. Patients were grouped according to surgical risk (benign and malignant disease, reoperation for benign and for malignant disease).
If the electrophysiological response was correlated to postoperative vocal cord function, the sensitivity of neuromonitoring was modest (86% in surgery for benign disease) to low (25% in reoperation for malignant disease); the positive predictive value was modest (overall rate 62%) but acceptable (87%) if corrected for technical problems. Specificity and negative predictive values were high (ie, overall >95%). Stimulation thresholds were not augmented in 11 patients, in whom postoperative palsy developed despite normal intraoperative recordings. Similarly, an electrical field response was elicited in 14 of 21 patients with preoperative vocal cord palsy. Electromyographic recordings did not reveal an abnormal amplitude or a decline in nerve conduction velocity.
Neuromonitoring is useful for identifying the recurrent laryngeal nerve, in particular if the anatomic situation is complicated by prior surgery, large tissue masses, aberrant nerve course. However, neuromonitoring does not reliably predict postoperative outcome.
我们评估了神经监测对不同适应证的甲状腺手术患者术后结局的预测能力。
有人主张进行神经监测以降低声带麻痹的风险并预测术后声带功能。
在单一中心对328例患者（502条神经有风险）进行前瞻性研究。使用Neurosign 100设备通过将记录电极经韧带放置到甲杓肌中来进行神经监测。通过逐步降低迷走神经和喉返神经的电流（从1 mA降至0.05 mA）来确定刺激阈值的累积分布。患者根据手术风险（良性和恶性疾病、良性和恶性疾病的再次手术）进行分组。
如果将电生理反应与术后声带功能相关联，神经监测的敏感性在良性疾病手术中为中等（86%），在恶性疾病再次手术中较低（25%）；阳性预测值中等（总体率为62%），但如果校正技术问题则可以接受（87%）。特异性和阴性预测值较高（即总体>95%）。11例患者的刺激阈值未升高，尽管术中记录正常，但术后仍发生了麻痹。同样，21例术前声带麻痹患者中有14例引发了电场反应。肌电图记录未显示振幅异常或神经传导速度下降。
神经监测有助于识别喉返神经，特别是在解剖情况因既往手术、大组织肿块、神经走行异常而复杂时。然而，神经监测不能可靠地预测术后结局。
