The non-recurrent inferior laryngeal nerve. Surgical experience

During the performance of 1018 thyroid operations, 1497 recurrent laryngeal nerves were identified and exposed. Of the 773 visualized nerves on the right side, 2 were found to be non recurrent (0.26%). This abnormality may represent a pitfall during thyroidectomy even for very experienced thyroid surgeons. We emphasize that the exposure and preservation of this vital structure is the standard of care and an essential component of routine dissection in thyroid surgery.     

Recognition of a non-recurrent laryngeal nerve during carotid endarterectomy

Cranial nerve injury during carotid endarterectomy (CEA), while infrequent, may have serious consequences. The recurrent laryngeal nerve is one of the most commonly injured cranial nerves. Fortunately, most of these injuries are temporary. Anatomic variations in the position of cranial nerves present challenges to surgeons during CEA. Although the occurrence of a non-recurrent laryngeal nerve (NRLN) is rare, proper recognition of this anatomic variation is critical in order to minimize complications. We present a case in which a NRLN was discovered intraoperatively and carefully preserved.     

First experiences in intraoperative neurostimulation of the recurrent laryngeal nerve during thyroid surgery of children and adolescents

Background: Intraoperative neurostimulation of the recurrent laryngeal nerve may reduce nerve palsy during thyroid surgery and is well established in adults. No data regarding the value of neuromonitoring during thyroid surgery in children have been available. Methods: In a retrospective study, the authors analyzed all children who underwent surgery in our department since 1995. Neurostimulation was performed as electromyography of the vocal muscle using an electrical stimulation electrode for identification of the recurrent nerve. Results: The authors performed thyroid resections in 97 children (mean, 11.1 years), 75 because of thyroid carcinoma. The recurrent nerve was identified in each patient. The neuromonitoring was used in 53 patients. Postoperatively, one temporary nerve palsy was identified in this group (1.89%). In the group of 44 nonstimulated patients, 2 temporary (4.55%) and one permanent nerve dysfunctions (2.27%) occurred. In all stimulated patients, the results of intraoperative neurostimulation were identical with the postoperative function of the vocal cords. Conclusions: The intraoperative neurostimulation of the recurrent laryngeal nerve is a safe and reliable procedure in children and adolescents. It may reduce nerve damage during thyroid surgery. The neuromonitoring of the recurrent nerve is of high prediction for the postoperative function of the vocal cords. J Pediatr Surg 37:1414-1418.     

Non-recurrent inferior laryngeal nerve

Surgical damage to the inferior laryngeal nerve is one of the most feared complications of thyroid surgery. Prevention of surgical injuries requires systematic, early exposure of the inferior laryngeal nerve. A detailed knowledge of anatomical variations is necessary. Non-recurrent inferior laryngeal nerve is a rare anomaly on the right side and is exceptional on the left. Whereas the typical course of the inferior laryngeal nerve is due to the embryological development of the aortic arch and supra-aortic vessels, non-recurrence is associated with a vascular anomaly such as a right retro-oesophageal subclavian artery. The nervous anomaly on the left side is possible only with the occurrence of cardiac dextroposition (situs viscerum inversus) and a left retro-oesophageal subclavian artery. The situation is more dangerous when a non-recurrent branch of the inferior laryngeal nerve is associated with a recurrent branch. This anomaly does not appear to be associated with a vascular anomaly in all cases. The authors describe three cases of right non-recurrent inferior laryngeal nerve observed and one recent case of combined non-recurrent and recurrent nerve, highlighting the anatomical and surgical features of this anomaly.     

Identification of recurrent inferior laryngeal nerve during a thyroid lobectomy

Based an their findings during thyroid operations and pathological examination of 100 specimens, the authors report the principal steps for identification and dissection of recurrent nerve during a thyroid lobectomy.     

甲状腺术中见喉不返神经一例

正患者女,64岁,因发现右侧颈部肿物于2017年12月11日入院。患者于20年前无明显诱因发现右侧颈部肿物,无局部红肿、疼痛、压痛等不适症状。近来肿物增大明显,无压迫症状,无声音嘶哑、饮水呛咳、吞咽困难、手足抽搐,无消瘦、多食、多汗、烦躁、性情改变、大便习惯改变。为求系统治疗来本院就诊,门诊检测后以"甲状腺肿物"收治。专科检查:颈部对称,无颈静脉怒张,颈动脉搏动无异常,无皮肤红肿破溃。     

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目的 探讨喉不返神经临床解剖特点,总结甲状腺手术如何识别喉不返神经以及预防其损伤的经验.方法 对天津医科大学附属肿瘤医院甲状腺颈部肿瘤科2004年1月至2006年12月诊治的3637例甲状腺肿瘤进行回顾性研究,分析手术中寻找显露喉返神经的情况.结果 甲状腺手术中常规显露喉返神经2875例,术中从正常喉返神经入喉处及(或)循迷走神经主干寻找出喉不返神经7例,且7例均发生于右侧,发生率为0.24%.结论 喉不返神经的临床发生率较低,但仍应引起医生的重视;喉不返神经变异多发生于右侧颈部.     

Critical course of the anterior laryngeal branch of the inferior laryngeal nerve

BACKGROUND: Although in the past few authors stated that the nerve penetrated the ligament of Berry, many new authors have not confirmed this assertion. Because of the clinical importance and indefiniteness of this subject, we aimed to present an anatomical study concerning the course of the inferior laryngeal nerve. METHOD: In 60 specimens, 102 sides were examined for this project, including 41 male and 19 female cadavers between the ages of 40 and 89 years at death. RESULTS: In two sides (one on the right and the other on the left), we found that the anterior (motor) laryngeal branch of the inferior laryngeal nerve penetrated the ligament unilaterally. The branch entered the ligament 5.6, 7.2 mm above its lower border and 3.3, 1.9 mm below its upper border. Distances from the entrance point of the branch to the trachea and thyroid were 9.5, 8.2 mm and 3.1, 2.2 mm, respectively. CONCLUSION: We found two anterior laryngeal branches penetrating the ligament of Berry. This subject is very important during the thyroid surgery, particularly during the division of the ligament for total lobectomy.     

Esophageal carcinoma with nonrecurrent inferior laryngeal nerve

Occurrence of a nonrecurrent inferior laryngeal nerve is quite rare. We present the case of a 70-year-old man with carcinoma of the esophagus. An abnormal right subclavian artery was detected preoperatively. This anomaly suggested that the right inferior laryngeal nerve branched directly from the vagal trunk. A carcinoma of the esophagus was resected, and lymph nodes were dissected. The right inferior laryngeal nerve was fully preserved, and the esophagus was primarily repaired.     

Identifying the recurrent laryngeal nerve by intraoperative neuromonitoring]

301 patients underwent thyroid surgery in 1998 by using the intraoperative neuromonitoring. The documentation was done prospectively. The system of intraoperative neuromonitoring consists of a stimulation circuit and an electromyographic record. We placed the deriving electrode transligamentally through the cricothyroid membrane. By relaxometry we investigated the influence of the relaxation level on the electromyographic record of the vocal muscle. Using a standardized operative technique we found a side-related rate of primary palsy of 2.3% (n = 13), from which 61.5% (n = 8) showed to be only temporary during a postoperative follow-up period. The intraoperative neuromonitoring with the purpose of identification of the recurrent laryngeal nerve is a safe and reliable method.     

A method for intraoperative identification of the recurrent laryngeal nerve

Thyroid and parathyroid surgery is associated with a 1 to 6 percent incidence of injury to the recurrent laryngeal nerve. Electrical stimulation of the recurrent laryngeal nerve produces vocal cord motion that can be monitored by means of a double-cuffed endotracheal tube. Twelve patients underwent prospective evaluation with this monitoring system, and in all 12, the recurrent laryngeal nerve was accurately identified and localized. The nerve could be stimulated from a mean distance of 1.7 cm by a mean amperage of 1.3 mA. Postoperative indirect laryngoscopy demonstrated normal vocal cord function in all patients.     

The "false" nonrecurrent inferior laryngeal nerve

BACKGROUND: Communicating branches between the cervical sympathetic system and the inferior laryngeal nerve (ILN) have been described. They usually originate from the middle cervical sympathetic ganglion (MCSG). These branches (sympathetic-inferior laryngeal anastomotic branch [SILAB]), usually thin, sometimes have the same diameter as the ILN. In this study we prospectively evaluated the frequency of this condition and its implications during surgical neck exploration. METHODS: From November 1998 to October 1999, 791 patients underwent surgical neck exploration, and 1253 ILNs were dissected: 656 on the right side (52.3%) and 597 on the left side (47.7%). RESULTS: On the right side, a nonrecurrent ILN was found in 3 cases (0.46%), and a large SILAB was found in 10 cases (1.5%). The SILAB originated from the superior cervical sympathetic ganglion in 2 cases and directly from the sympathetic trunk above the MCSG in 8 cases. No anomalous branch was found on the left side. CONCLUSIONS: The SILAB may originate not only from the MCSG but also from the superior cervical sympathetic ganglion or directly from the sympathetic trunk. When the SILAB is as large as the ILN, it could be mistaken for a nonrecurrent ILN. The awareness of this anatomic condition during neck dissection may help to avoid injuries of the genuine ILN running in the usual pathway.