Tomoda Chisato, Hirokawa Yoshihiro, Uruno Takashi, Takamura Yuuki, Ito Yasuhiro, Miya Akihiro, Kobayashi Kaoru, Matsuzuka Fumio, Kuma Kanji, Miyauchi Akira
Kuma Hospital, 8-2-35 Shimoyamate-dori, Chuo-ku, Kobe, 650-0011, Japan.
World J Surg. 2006 Jul;30(7):1230-3. doi: 10.1007/s00268-005-0351-z.
Recurrent laryngeal nerve (RLN) palsy after thyroidectomy, although infrequently encountered, can decrease quality of life. In addition to the hoarseness that occurs with unilateral RLN palsy, bilateral RLN palsy leads to dyspnea and often to life-threatening glottal obstruction. Therefore, intraoperative awareness of the nerve's status is of great importance. This study examined the sensitivity and specificity of a palpation technique to detect contraction of the posterior cricoarytenoid muscle (PCA) through the posterior hypopharyngeal wall while the RLN was being stimulated with a disposable nerve stimulator during thyroid surgery (the laryngeal palpation test) to predict postoperative RLN deficits.
A total of 2197 RLNs in 1376 patients were identified to be at risk of injury during thyroidectomy performed between July 2003 and August 2004. Postoperative RLN integrity was assessed using direct laryngoscopy or laryngofiberoscopy to visualize vocal fold mobility.
Altogether, 76 RLNs failed to elicit a PCA contraction in response to nerve stimulation, and 80 cases of temporary vocal cord palsy and 21 cases of permanent vocal cord palsy were recognized on postoperative evaluation. For postoperative vocal cord palsy, the sensitivity and specificity of the laryngeal palpation test were 69.3% and 99.7%, respectively, with a positive predictive value of 92.1% and negative predictive value of 98.5%. For permanent vocal cord palsy, the sensitivity and specificity were 85.7% and 97.3%, respectively, with a positive predictive value of 23.7% and negative predictive value of 99.8%.
The laryngeal palpation test is not a particularly useful method for predicting the level of RLN function after thyroidectomy. All patients must be examined postoperatively by direct laryngoscopy or laryngofiberoscopy to check vocal cord mobility. Even if there is no contraction of the PCA and we detect vocal cord palsy immediately after surgery, vocal cord palsy often recovers within 1 year when visual preservation of RLN is successful.
甲状腺切除术后喉返神经（RLN）麻痹虽不常见，但会降低生活质量。单侧RLN麻痹会导致声音嘶哑，双侧RLN麻痹则会引起呼吸困难，常导致危及生命的声门梗阻。因此，术中了解神经状况至关重要。本研究检测了一种触诊技术的敏感性和特异性，该技术是在甲状腺手术期间用一次性神经刺激器刺激RLN时，通过下咽后壁检测环杓后肌（PCA）收缩情况（喉部触诊试验），以预测术后RLN功能缺损。
在2003年7月至2004年8月期间进行的甲状腺切除术中，共确定1376例患者的2197条RLN有损伤风险。术后通过直接喉镜检查或纤维喉镜检查评估声带活动度，以判断RLN的完整性。
总共76条RLN在神经刺激后未引起PCA收缩，术后评估发现80例暂时性声带麻痹和21例永久性声带麻痹。对于术后声带麻痹，喉部触诊试验的敏感性和特异性分别为69.3%和99.7%，阳性预测值为92.1%，阴性预测值为98.5%。对于永久性声带麻痹，敏感性和特异性分别为85.7%和97.3%，阳性预测值为23.7%，阴性预测值为99.8%。
喉部触诊试验并非预测甲状腺切除术后RLN功能水平的特别有用的方法。所有患者术后都必须通过直接喉镜检查或纤维喉镜检查来检查声带活动度。即使PCA没有收缩，且我们在手术后立即检测到声带麻痹，但当RLN在视觉上得以保留时，声带麻痹通常会在1年内恢复。
