The intracranial branch; A rare anatomical variation of the recurrent laryngeal nerve; Case report

IntroductionThe recurrent laryngeal nerve (RLN) originates from the Vagus nerve intrathoracically. It passes through the tracheoesophageal groove (TEG) in the neck and different variations in this section were observed. The RLN is at highest risk for injury during the thyroid surgery. Therefore, it is important to know variations to decrease the injury effectively.Presentation of caseA 50 years-old woman with no thyroid related complaints except for enlargement of the thyroid gland in recent 12-months that annoyed her during neck movement and for aesthetic features. Medical, surgical, drugs, irradiation history, laboratory data, and physical examination was unremarkable except for multi-lobulated enlarged thyroid gland. The CT scanning study revealed intrathoracic extension of the gland. Patient underwent total thyroidectomy with suspicious diagnosis of multinodular goiter which was confirmed later by pathologic study. Intraoperative exploration of the right RLN discovered an intracranial branch originating from the recurrent laryngeal trunk just beneath the inferior thyroid artery (ITA) at the level of the nerve intersection. The branch then passed laterally about 1 cm and penetrated in ipsilateral carotid sheath.DiscussionThe RLN has different anatomical variations in either the right or the left side of the neck. However extra-laryngeal nerve branching is the most common variation but other seldom variations including the non-RLN, and intracranial branch should be mentioned by surgeon intraoperatively.ConclusionTo decrease iatrogenic injuries to RLN and its associated nerve branches knowledge of the nerve anatomy is mandatory for surgeon to prevent morbid side effects.     

A novel method for lymphadenectomy along the left laryngeal recurrent nerve during thoracoscopic esophagectomy for esophageal carcinoma

Background

Due to limited space in the left upper mediastinum, complete dissection of lymph nodes (LN) along left recurrent laryngeal nerve (RLN) is difficult. We herein present a novel method for lymphadenectomy along the left RLN during thoracoscopic esophagectomy in the semi-prone position for esophageal carcinoma. The method, suspension the esophagus and push aside trachea, allows en bloc lymphadenectomy along the left RLN from the below aortic arch to the thoracic inlet.

Methods

Between September 2014 and September 2015, a total of 110 consecutive patients with esophageal carcinoma were treated with thoraco-laparoscopic esophagectomy with cervical anastomosis in the semi-prone position. Outcomes between those who received surgery with the novel method and conventional surgery were compared.

Results

Fifty patients underwent the novel method and sixty received conventional surgery. The operative field around the left RLN was easier to explore with the novel method. The estimated blood loss was less (23.7±8.2 vs. 34.2±10.3 g, P=0.001), and the number of harvested LNs along the left RLN was greater (6.4±3.2 vs. 4.1±2.8 min, P=0.028) in the novel method group, while the duration of lymphadenectomy along left RLN was longer in the novel method group (28.2±3.9 vs. 20.3±2.8 min, P=0.005). The rate of hoarseness in the novel and conventional groups was 10% and 16.7%, respectively. No significant difference in postoperative morbidity related to the left RLN was noted between the groups.

Conclusions

The novel method during semi-prone esophagectomy for esophageal carcinoma is associated with better surgeon ergonomics and operative exposure.     

不同解剖标志显露喉返神经的比较和体会

目的总结甲状腺手术中4种不同解剖标志暴露喉返神经的方法,比较各自的优缺点。方法分析400例甲状腺手术,依据不同解剖标志显露喉返神经,分为四组:甲状腺体下极(A组),甲状腺下动脉(B组),甲状软骨下角(C组),气管食管旁沟(D组)。对比解剖时间、神经损伤(暂时性和永久性)。结果 C组显露时间最短,B组最长。各组的出血量无明显差异。超声刀有助减少手术出血,缩短手术时间。结论根据甲状腺的病变特点和手术者的习惯,采取个体化的解剖路径显露喉返神经,有助于减少损伤。     

45条喉返神经喉外分支变异手术体会

[目的]探讨喉返神经喉外分支变异的定义、发生率及手术体会.[方法]对42例喉返神经喉外分支变异病例分支的解剖特点、手术方式和手术转归进行总结和分析.[结果]42例患者中共有45条喉返神经喉外分支变异,其中32条有2个分支,6条有3个分支,5条有4个分支,2条有5个分支;25例为常规手术,11例为miccoli手术,9例使用了喉返神经探测仪;5例患者手术后出现不同程度的声音嘶哑,均给予对症治疗,随访6个月内恢复.[结论]喉返神经喉外分支变异是喉返神经损伤的高危因素之一,借助腔镜和术中神经监测技术可以有效保护喉返神经喉外分支,降低损伤概率.     

喉返神经解剖病理变异对甲状腺癌术中规范化神经监测的影响

目的 观察甲状腺癌喉返神经(RLN)发生解剖病理变异时对术中神经监测(IONM) 4步法的影响,为IONM规范化操作提供理论支持及应用策略.方法 回顾性分析2012年6月至2014年12月在解放军总医院普通外科行甲状腺癌手术并于术中行IONM的160例的临床资料,根据术中显露RLN形态特征,分为变异组55例(解剖变异、病理变异)与无变异组105例.评估RLN解剖病理变异对IONM 4步法操作的影响.结果 术中显露RLN共297根.RLN识别率变异组为89.32%(92/103)顺利识别,其中11根(10.68%,11/103)寻找困难;无变异组100%均顺利识别,两组比较差异有统计学意义(P<0.05);术中RLN显露部位为气管食管沟内194根(65.32%)、气管旁75根(25.25%)、食管旁17根(5.72%)、甲状腺腺体内11根(3.71%);评价术后刺激RLN所得EMG波形对诊断术后声带麻痹的灵敏性与特异性,发现阴性预测值100%,阳性预测值仅25.00%.结论 RLN变异造成IONM4步法操作时RLN定位困难,R1值难以获取,干扰EMG波形研读;准确认知RLN解剖病理学形态特征,有利于提升IONM规范化操作水平.     

Evaluating the safety of the Harmonic Scalpel around the recurrent laryngeal nerve

Background: The Harmonic Scalpel (HS) is widely used in thyroidectomy. Determining the safety margin of using the HS near the recurrent laryngeal nerve (RLN) is helpful in preventing the injury to this nerve during thyroidectomy. Methods: The parameters of evoked electromyography (EEMG) of vocal muscles before and after using the HS at a power level of 3 were recorded in a rabbit model. Masson staining was used to determine lateral injury caused by incisions using the HS. Results: After the activated tip of the HS made contact with the RLN for ≥1 s or was placed 1 mm from the nerve for 3 or 5 s or 2 mm from the nerve for 5 s, significant changes were observed in the minimal stimulus current intensity threshold, the optimal stimulus current intensity threshold, the onset latency and the wave amplitude of EEMG. After the activated HS tip touched the RLN or was placed 1 mm to the nerve for ≥1 s or 2 mm to the nerve for 5 s, significant changes were found in peak latency. The thickness of injured lateral tissue was <1, 1–2 and >2 mm when using HS for 1, 3 and 5 s, respectively. Conclusion: When used near the RLN at a power level of 3, the activated HS tip should be ≥2 mm from the nerve and the duration of incision should be ≤3 s.