喉返神经的应用解剖研究

目的为甲状腺手术术中对喉返神经的定位和保护提供解剖学基础。方法采用经福尔马林固定的60具成人标本(男40,女20)共120侧,用解剖学方法对喉返神经及其分支进行定位观测,以及观测甲状腺下动脉、甲状软骨下角和甲状腺下极等3种解剖标志与喉返神经的毗邻关系。结果(1)喉返神经的分支有喉支和喉外支,前者在喉前多分为前、后支。(2)喉返神经与甲状腺下动脉的关系分5种类型。(3)91.7%(110侧)喉返神经的喉支多在距甲状腺下角尖端(16.9±7.2)mm处分前、后支,喉外支多在其下(10.4~70.3)mm范围内发出。(4)59.2%的喉返神经分支发出部位在甲状腺下极平面以上,距甲状腺下极平面距离(11.25±7.1)mm。结论在甲状腺手术中应注意喉返神经的变异,通过暴露和辨认喉返神经及其分支防止其损伤。     

与颈部手术相关的喉返神经的应用解剖

目的 :为颈部手术中喉返神经的定位和保护提供形态学和局部解剖学基础。方法 :解剖 5 0具 (10 0侧 )成人颈部尸体标本 ,对喉返神经及其分支进行定位观测。结果 :(1)喉返神经的分支有喉支和喉外支 ,前者在入喉前多分为前支、后支。 87%的喉返神经分支呈树枝状 ,13 %的喉返神经分支之间或分支与颈交感干之间相互吻合呈袢状。 (2 )有 2 %的双喉返神经和 1%的非返喉下神经。 (3 ) 94%的喉返神经的喉支多在距甲状腺下角尖端 (16.9± 7.6)mm处分为前、后支 ,喉外支多在其下 10 .4～ 70 .4mm范围内发出。 (4 )喉返神经与甲状腺下动脉的关系分为 5种类型。 (5 )喉返神经与颈部食管及颈动脉鞘的位置关系复杂。结论 :在颈部相关手术中应注意喉返神经的变异 ,通过显露和辨认喉返神经防止其损伤。     

Arterial supply to the thyroid gland and the relationship between the recurrent laryngeal nerve and the inferior thyroid artery in human fetal cadavers

The aim of this study was to identify the arterial supply to the thyroid gland and the relationship between the inferior thyroid artery (ITA) and the recurrent laryngeal nerve (RLN) in fetal cadavers using anatomical dissection. The anterior necks of 200 fetuses were dissected. The origins of the superior thyroid artery (STA) and the ITA and location of the ITA in relation to the entrance of the thyroid lobe were examined. The relationship between the ITA and the RLN was determined. The origins of the STA were classified as: external carotid artery, common carotid artery (CCA), and the thyrolingual trunk. The origins of the ITA were the thyrocervical trunk and the CCA. The ITA was absent on the left side in two cases. The relationship of the RLN to the ITA fell into seven different types. Type 1: the RLN lay posterior to the artery; right (42.5%), left (65%). Type 2: the RLN lay anterior to the artery; right (40.5%), left (22.5%). Type 3: the RLN lay parallel to the artery; right (11.5%), left (7%). Type 4: the RLN lay between the two branches of the artery; right (1%), left (3.5%). Type 5: The extralaryngeal branch of the RLN was detected before it crossed the ITA; right (4.5%), left (0%). Type 6: the ITA lay between the two branches of the RLN; right (0%), left (0.5%). Type 7: the branches of the RLN lay among the branches of the ITA; right (0%), left (0.5%). The results from this study would be useful in future thyroid surgeries. Clin. Anat. 27:1185–1192, 2014. © 2014 Wiley Periodicals, Inc.     

喉返神经喉外分支的显微解剖及临床意义

目的探讨甲状腺手术区域喉返神经(RLN)的解剖特点和方法。方法运用大体解剖的方法,对48例成人标本甲状腺手术区域的RLN及其周围毗邻结构进行了观测。结果 48例96侧成人标本中,29%RLN主干穿过环咽肌肌束至致密结缔组织膜下缘,71%RLN主干走行在环咽肌深面。69%RLN在距离甲状软骨下角尖端(15.2±5.5)mm处分为前、后两支,前支多于环状软骨侧方下缘距离甲状软骨下角尖端(5.9±1.8)mm处穿过结缔组织膜,后支入喉点距甲状软骨下角尖端(4.8±2.1)mm;31%RLN未见分支。结缔组织膜下缘RLN与甲状腺下动脉(ITA)分支的关系为:66%(63/96)RLN位于ITA前方,27%(32/96)位于ITA后方。结论大多数RLN具有喉外分支,在以甲状软骨下角作为标志寻找RLN时,要同时找寻RLN及喉外分支的入喉点。ITA与RLN的关系复杂多变,ITA不作为RLN定位的首选。     

The inferior laryngeal nerve: surgical and anatomic considerations. Report of 251 thyroidectomies

This surgical anatomic study aimed to determine (1) the anatomic relation of the laryngeal inferior nerve with the inferior thyroid artery, (2) the existence of extralaryngeal branches of division of the nerve and (3) the size of the nerve seen macroscopically. Two hundred and fifty-one patients underwent thyroid surgery during a period of 30 months. There were 50 males and 201 females. The male population underwent 28 total thyroidectomies, 13 left lobectomies and 9 right lobectomies. The female population underwent 124 total thyroidectomies, 33 left lobectomies and 44 right lobectomies. On the right side: the nerve was found superficial to the artery in 70.24% of females and 51.35% of males, the nerve was divided in 23.81% of females and 21.62% of males and seemed unusually thin in 14.29% of females and 5.41% of males. On the left side: the nerve was found superficial to the artery in 87.26% of females and 95.12% of males, the nerve was divided in 15.29% of females and 14.63% of males and seemed unusually thin in 10.83% of females and 2.44% of males. In conclusion, the inferior laryngeal nerve is characterized by its important anatomic variations, especially on the right side. These variations might be different even between males and females. Knowledge of these variations is very important in order to best identify and preserve the inferior laryngeal nerve during thyroid surgery.

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Electronic Supplementary Material The french version of this article is available in the form of electronic supplementary material and can be obtained by using the Springer Link server located at .

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Le nerf laryngé inférieur: considérations anatomiques et chirurgicales. A propos de 251 thyroïdectomies

Résumé Il s'agit d'une étude anatomique per-opératoire ayant pour but de préciser (1) les rapports du nerf laryngé inférieur avec l'artère thyroïdienne inférieure, (2) l'existence de branches de division nerveuses extra-laryngées et (3) une appréciation subjective du calibre macroscopique du nerf. 251 patients ont bénéficié d'une chirurgie thyroïdienne (50 hommes et 201 femmes) sur une période de 30 mois. Pour les hommes ont été réalisées 28 thyroïdectomies totales, 13 lobo-isthmectomies gauches et 9 lobo-isthmectomies droites. Pour les femmes ont été réalisées 124 thyroïdectomies totales, 33 lobo-isthmectomies gauches et 44 lobo-isthmectomies droites. Du côté droit, le nerf était superficiel par rapport à l'artère dans 70,24% des cas chez les femmes et 51,35% chez les hommes, il était divisé dans 23,81% des cas chez les femmes et 21,62% chez les hommes et il était anormalement fin dans 14,29% des cas chez les femmes et 5,41% chez les hommes. Du coté gauche, il était profond dans 87,26% des cas chez les femmes et 95,12% chez les hommes, il était divisé dans 15,29% des cas chez les femmes et 14,63% chez les hommes et il était anormalement fin dans 10,83% des cas chez les femmes et 2,44% chez les hommes. En conclusion, le nerf laryngé inférieur est caractérisé par ses grandes variations anatomiques, en particulier du côté droit. De plus ces variations sont possiblement différentes entre les sexes. La connaissance de ces variations est indispensable pour le repérage et la préservation du nerf au cours de la chirurgie thyroïdienne.

     

喉返神经在颈部的局部解剖及临床应用

目的　为使在甲状腺手术中避免误伤喉返神经提供解剖学基础。方法　对 4 5具 (男 30具 ,女 15具 )成人尸体喉返神经和甲状腺下动脉之间的关系进行解剖、观测。结果　喉返神经平均横径为 1 93± 0 35mm。喉返神经入喉支以 2 - 5干型的为多见 ,占 6 8 9%。甲状腺下动脉的直径为 2 6 1± 0 .2 3mm。喉返神经和甲状腺下动脉之间的关系 ,左右侧有明显差异。结论　喉返神经横径平均在 1 93±0 35mm之间 ;喉返神经在甲状腺峡平面分支的最为普遍 ;神经行于动脉主干之后的有 4 8 9% ,为多见 ;神经行于动脉前及动脉分支间的例数差不多 ,左侧神经行于动脉之后的多见 ,而右侧神经行于动脉之前的多见 ,左右有明显差异 ,在颈部手术时参考     

An anatomical study of the recurrent laryngeal nerve: its branching patterns and relationship to the inferior thyroid artery

The aim of this study was to provide information about the morphology and topography of the recurrent laryngeal nerve (RLN), its external features and branches, as well as its relationship to the inferior thyroid artery, the inferior horn of the thyroid cartilage and the thyroid gland. The RLNs in 50 adult cadavers (100 sides) were dissected and analyzed. A communicating loop connecting one branch of the RLN to another or a twig originating from the cervical sympathetic trunk was present in 13 of 100 sides. A double left RLN appeared in 2 sides; a right non-recurrent inferior laryngeal nerve appeared in one side. All of the RLNs, including looped ones, bifurcated into laryngeal branches and extralaryngeal branches, with most of the former further dividing into the anterior and posterior branches entering the larynx. The relations of the RLN to the inferior thyroid artery, the inferior horn of the thyroid cartilage and the thyroid gland were inconstant. The information gained from this study will be of value in thyroid surgery.     

Superior approach to the inferior laryngeal nerve in thyroid surgery: anatomy, surgical technique and indications

Goals of the study To describe the anatomical bases of the surgical access to the higher part of the thyroid lobe, with first location of the inferior laryngeal nerve at its laryngeal penetration, to discuss the advantages and disadvantages of this surgical technique and to determine the operational indications.Population and method A prospective study of surgical anatomy performed over a period of 18 months was conducted. A total of 25 (22 women and 3 men) patients with cervicothoracic goitre underwent total thyroidectomy. Thyroid lobectomies were performed using the technique of “capsular thyroidectomy”, with first location and complete dissection of the inferior laryngeal nerve. A neurostimulator was systematically used for the location of the inferior laryngeal nerve and also the external laryngeal nerve.Results The first detection of the inferior laryngeal nerve at the top of the thyroid lobe was positive in 49/50 cases. A superior parathyroid gland was found in 75% of cases and an inferior parathyroid gland in 37.5% of cases. The external laryngeal nerve was stimulated and respected in 12,5% of cases. No voice trouble, no laryngeal palsy and no definitive hypoparathyroidism occurred after surgery.Conclusion Safeguarding of the inferior laryngeal nerve is the principal and obligatory stake in thyroid surgery. Locating the inferior laryngeal nerve at the level of its laryngeal penetration at the superior pole of the thyroid region is necessary in cases of particular situations: huge cervicothoracic goitres, re-operative procedures and various anatomical variations. The use of a neurostimulator secures this technique.     

A detailed study of the relationship between the external laryngeal nerve and superior thyroid artery,including its glandular branches

The external layrngeal nerve (ELN) may be at risk during thyroidectomy. Because the relationship between the ELN and superior thyroid artery (STA) can be variable, we aimed to investigate their relationship in detail. In human cadavers, 81 ELN and STA and their branches were carefully dissected. The position of the nerve was classified as medial (Group I, on 76.5% sides), lateral (Group II, on 20.9% sides), or posterior (Group III, on 2.4% sides) to the origin of the STA. In Group Ia, the nerve did not cross the artery while it did cross the artery in Group Ib. In Group II, the nerve was located lateral to the origin of the artery and crossed it. In Group III, the nerve coursed downward posterior to the artery. In conclusion, the topography of the ELN showed much more variability in its relationship to the STA than is described in the literature. Such variations should be kept in mind during surgery of the anterior neck. It is our hope that such data will decrease surgical morbidity following surgery of the anterior neck. Clin. Anat. 26:814–822, 2013. © 2012 Wiley Periodicals, Inc.     

甲状腺手术中识别喉返神经的解剖标志

目的探讨甲状腺手术中用以识别喉返神经的5种有效的解剖标志,为手术中避免误伤喉返神经提供形态学资料。方法采用经福尔马林防腐固定的50具成人标本(男40例,女10例)共100侧,用解剖学方法观测甲状软骨下角尖、甲状腺下动脉、甲状腺下极、气管食管沟和甲状腺悬韧带等5种解剖标志与喉返神经的毗邻关系。结果甲状软骨下角距喉返神经入喉处(6.3±1.9)mm;甲状腺下动脉与喉返神经的毗邻关系有五种类型;右侧喉返神经有64.6%、左侧100%直行于气管食管沟内,在颈根部右侧喉返神经偏离气管食管沟2.1~10.2mm;喉返神经与甲状腺下动脉交叉处位于甲状腺下极之上者占81.1%;喉返神经行于甲状腺悬韧带后方者占92.0%。结论甲状腺手术识别喉返神经的五种解剖标志中,以甲状软骨下角尖(或环甲关节)和甲状腺悬韧带较可靠,其次为甲状腺下极、甲状腺下动脉和气管食管沟。     

Relation of the external branch of the superior laryngeal nerve to the superior pole of the thyroid gland: an anatomical study

The external branch of the superior laryngeal nerve (ELN) is intimately associated with the superior thyroid artery (STA) in relation to the superior pole of the thyroid gland, rendering it vulnerable to injury during the ligation of this vessel during thyroidectomy. Although most texts acknowledge the fact that the nerve is in close relation to the STA, there has not been an anatomical study to relate the position of the ELN to the superior pole of the thyroid gland. The aim of this study was to determine the shortest distance, from the most superior point of the thyroid gland, to the ELN. Bilateral micro-dissection on 43 adult cadavers, excluding those with thyroid pathology and previous thyroidectomies, was undertaken. The most superior point of the superior pole of the thyroid gland was identified and the shortest distance to the ELN was measured with a digital calliper (accuracy 0.01 mm). The metric study indicated a mean distance from the ELN to the superior pole of a normal sized thyroid gland of 5.76 mm (range: 2.00-11.26) on the right, and 6.17 mm (range: 2.78-13.48) on the left. From the literature, it is clear that the ELN may even be closer to the superior pole of an enlarged thyroid gland. The recommendation to stay on the substance of the superior pole of the thyroid gland when ligating the STA remains valid, as the nerve is extremely close in relation to the superior pole of the normal thyroid gland.     

An applied anatomical study of the superior laryngeal nerve loop

The aim of this study was to provide some specific information about the morphology and topography of the superior laryngeal n., its branches, and its anastomoses with the cervical sympathetic chain, as well as its relations with the thyroid gland. Sixty adult cadavers, ie 120 superior laryngeal nn., were dissected and analysed. An anastomotic loop connecting the cervical sympathetic chain and the distal laryngeal n. was present in 111 of the 120 cases. The morphology of this loop made it possible to define 5 different groups. This study supplies information valuable in thyroid surgery.     

The superior laryngeal nerve loop and its surgical implications

Summary Based upon findings from 60 cadavers (120 sides), the incidence of superior laryngeal nerve loop, connecting the cervical sympathetic chain and the superior laryngeal nerve and its branches, the external and internal laryngeal nerve, was 98.3% (118 out of 120 sides). In most cases the loop connected the sympathetic chain and the external laryngeal nerve. The external laryngeal nerve was looped, and not linear as traditionally thought. The loop could be divided into three categories, V-shaped, U-shaped and mixed, and subdivided into 5 types and 17 subtypes according to morphological variation. The loop without exception innervated not only the cricothyroid muscle, but also the thyroid gland. The loop is one of the origins of the thyroid nerve. It seems that for thyroid surgery the loop, when lower in position, should be carefully separated from the superior thyroid vessels before the latter are ligated, in order to preserve a normal nerve supply to the muscle as well as to the part of the gland that remains after surgery.

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L'anse du nerf larynge supérieur, étude anatomique et applications chirurgicales

Résumé La fréquence d'une anse du nerf laryngé supérieur réalisant une anastomose entre la chaine sympathique cervicale et le nerf laryngé supérieur et/ou ses branches (rameau laryngé externe et ingerne), est de 98,3 % (118/120). Ce résultat s'appuie sur l'étude de 60 cadavres. Dans la plupart des cas, l'anastomose se fait entre la chaine sympathique cervicale et le rameau laryngé externe. Ce rameau laryngé externe a un trajet curviligne et non linéaire conformément aux données classiques. Il existe trois catégories d'anses : en "V", en "U" et mixte ; on peut également les subdiviser en 5 types et 17 sous-types en fonction des variations morphologiques. Cette anse innerve constamment non seulement le muscle cricothyroïdien mais aussi la glande thyroïde dont elle fournit une partie de l'innervation. Lors de la chirurgie thyroïdienne, si l'anse est en position basse, les nerfs doivent être soigneusement disséqués et séparés des vaisseaux thyroïdiens supérieurs avant ligature de ces derniers de façon à conserver l'innervation normale du muscle et de la partie restante de la glande.

     

Anatomical intra-laryngeal anterior branch study of the recurrent (inferior) laryngeal nerve

Summary The studies are based upon 60 dissections of the recurrent laryngeal n. (inferior laryngeal n.). The authors describe in detail the branches destined for the intrinsic musculature of the larynx. This study is a working approach for interventions of selective laryngeal reinnervation in man. The conclusion is that, it is necessary to resect the inferior cornu of the thyroid cartilage, to reach the abductor and adductor branches of the vocal cord.

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Etude anatomique de la branche antérieure intralaryngée du n. laryngé inférieur

Résumé Cette étude porte sur 60 dissections de n. laryngé inférieur. Les auteurs décrivent en détail les branches destinées à la musculature intrinsèque du larynx. Cette étude est un travail d'approche pour les interventions de réinnervation laryngée sélective chez l'homme. Leur conclusion est qu'il est nécessaire de réséquer la corne inférieure du cartilage thyroïde pour aborder les branches abductrice et adductrice des plis vocaux.

     

Absence of the left inferior thyroid artery: clinical implications

Dissection of an adult male cadaver revealed an absence of the left inferior thyroid artery; its usual area of distribution to the thyroid gland was supplied by the right inferior thyroid artery. Absence of the left inferior thyroid artery occurs in 1-6% of cases. The inferior thyroid artery arises commonly from the thyrocervical trunk, passes posterior to the carotid sheath and supplies the inferior pole of the corresponding lobe of the thyroid gland; its branches can course anterior or posterior to or between branches of the recurrent laryngeal nerve. During thyroid surgery it is imperative to identify the relationship of the inferior thyroid artery to the recurrent laryngeal nerve or to establish its absence because injury to the nerve can be a major complication; awareness of significant variations of the surgical anatomy of the thyroid gland is vital for preserving the integrity of important structures.     

Laryngeal branching pattern of the inferior laryngeal nerve, before entering the larynx

The objective of the present work was to investigate the laryngeal branching pattern of the inferior laryngeal nerve (ILN) in detail before the branches entered the larynx. In 49 specimens 96 sides were examined for this project, including 27 males and 22 female cadavers. In 7 sides (7.3%, 5 on the left and 2 on the right) the ILN passed as a single trunk into the larynx below the inferior constrictor muscle. In 82 sides (85.4%, 40 on the left and 42 on the right) two laryngeal branches originated from the nerve. The nerve divided either just before entering the larynx (58.3%, 24 on the left and 32 on the right) or 15–32 mm below the inferior constrictor muscle (27.1%, 16 on the left and 10 on the right). In 69 sides (71.8%), the anterior and/or posterior laryngeal branches subdivided into one or two sub-branches. The anterior (observed in 49 sides, 51%) and posterior laryngeal branches supplied all intrinsic laryngeal muscles except the cricothyroid muscle and the mucosa below the vocal cords, respectively, while their sub-branches reached the cricopharyngeal part of the inferior constrictor muscle, esophagus and/or the thyroid gland. In 7 sides (7.3%, 4 on the left and 3 on the right) the nerve divided into three laryngeal branches. In conclusion, the branching pattern of the nerve may be important pitfalls of the thyroidal and laryngeal surgery. Owing to this the surgeon should keep in mind the risk of extra laryngeal division of the nerve and not confuse laryngeal and extra laryngeal branches.     

An applied anatomical study on the recurrent laryngeal nerve and inferior thyroid artery

Purpose  

The aim of this study was to provide some important information about the morphology and topography of the recurrent laryngeal nerve (RLN) and inferior thyroid artery (ITA), which significantly helps localize and protect the RLN in neck surgery, especially in thyroid surgery.     

The recurrent laryngeal nerve (RLN): application to transhiatal oesophagectomy

Summary To emphasize the risks of recurrent laryngeal nerve lesions during transhiatal oesophagectomy an anatomical study of the course of the recurrent laryngeal nerve (RLN) was performed. Twenty RLN were dissected in their thoracic portion. This work showed the constancy of the low origin of the nerve in the adult under the aortic arch, and its course in the tracheal angle. It confirmed the close connections of the nerve with the posterior mediastinal viscera. Lastly, it displayed oesophageal nerve branches arising from the RLN and a few anastomoses between them and the tracheal nerve branches. This anatomical disposition resulted into the difficulty of transhiatal oesophaphagectomies and the risk of injury of the recurrent laryngeal nerve. The possibility of nerve lesions can explain the respiratory complications of this surgical approach.

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Le nerf laryngé récurrent : Application à l'sophagectomie trans-hiatale

Résumé Pour souligner les risques de lésions récurrentielles dans l'oesophagectomie trans-hiatale une étude anatomique du nerf récurrent thoracique est réalisée. Vingt nerfs récurrents thoraciques ont été disséqués. Ce travail montre la constance de la naissance basse de ce nerf chez l'adulte, sous la crosse de l'aorte, et son trajet dans l'angle oeso-trachéal. Il confirme les rapports intimes de ce nerf avec les viscères du médiastin postérieur. Enfin, il met en évidence des branches nerveuses oesophagiennes naissant du nerf récurrent thoracique et quelques anastomoses entre celles-ci et les branches nerveuses trachéales. De cette disposition anatomique résulte la difficulté des oesophagectomies trans-hiatales et le risque de lésion récurrentielle. La possibilité de lésion nerveuse peut expliquer les complications respiratoires d'une telle technique chirurgicale.

     

甲状腺手术中对喉返神经和喉上神经保护的临床研究

目的 探讨甲状腺手术中喉返神经(RLN)、喉上神经(SLN)的保护方法,以避免或减少术后永久性神经损伤的发生率。方法 对东南大学医学院附属南京同仁医院耳鼻咽喉头颈外科,2013年6月—2014年11月行甲状腺精细化操作手术治疗141例患者的临床资料进行回顾性分析。其中男37例、女104例,年龄9~78岁。行甲状腺全切54例,甲状腺腺叶切除58例,甲状腺腺叶切除+对侧部分切除29例;其中二次手术者10例,行Ⅵ区清扫者18例。术中RLN显露者121例,未显露者20例。结果 本组141例均顺利完成手术。术后并发RLN暂时性损伤5侧,占2.56%(5/195),给予激素、神经营养药物治疗,并配合发音训练,3个月内神经功能均恢复正常;其中RLN显露组占2.5%(3/121),未显露组占5%(1/20),组间比较差异无统计学意义(χ²=0.396, P＞0.05)。无一例并发RLN永久性损伤和SLN损伤。结论 熟悉RLN、SLN与甲状腺的正常解剖与变异情况,应用被膜解剖技术精细操作,术后可以避免神经的永久性损伤。一旦发生神经损伤,及时给予对症处理,提高患者的生活质量。