Anatomical Variations in Recurrent Laryngeal Nerves in Thyroid Surgery

Objective: To study terminal bifurcation of recurrent laryngeal nerves (RLNs) with original direction to larynx entry and to decrease the risk of vocal cord paralysis in thyroid patients. Methods: The RLNs of 294 patients (482 sides) were dissected according to the branches into the larynx, and the original direction of each RLN trunk in thyroid surgery was recorded. Results: (1) About 30.9% of the RLNs gave off multiple branches into the larynx. (2) Two and 3 branches of RLNs into the larynx were found in 25.5% and 5.4% of the cases, respectively. (3) In 0.4% or 2 cases, the RLN trunk combined with the inferior branch of the vagus nerve. (4) Nonrecurrent laryngeal nerve appeared in 2 cases. (5) On the left side, 68.0%, 25.6%, and 6.4% of cases were found with 1, 2, and 3 bifurcations of RLN to larynx entry, respectively. On the right side, 69.8%, 25.8%, and 4.4% cases were identified with 1, 2, and 3 bifurcations of RLN to larynx entry, respectively. (6) The combining dissection approach was proved as successful and safe for protecting the RLN with no permanent RLN paresis. Conclusions: Because of the anatomical variation in RLNs with extralaryngeal bifurcation, it is necessary to increase the awareness of surgeons about these variations so as to protect bifurcated nerves in thyroid surgery.

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Non-recurrent laryngeal nerve related to thyroid surgery: report of three cases

The Journal of Laryngology & Otology ◽

10.1017/s0022215107008389 ◽

2007 ◽

Vol 122 (7) ◽

pp. 757-761 ◽

Cited By ~ 17

Author(s):

C Page ◽

P Monet ◽

J Peltier ◽

B Bonnaire ◽

V Strunski

Keyword(s):

Recurrent Laryngeal Nerve ◽

Subclavian Artery ◽

Thyroid Surgery ◽

Anatomical Variation ◽

Anatomical Variations ◽

Laryngeal Nerve ◽

Frequency Of Occurrence ◽

Laryngeal Nerves ◽

Recurrent Laryngeal Nerves ◽

The Right

AbstractPurpose of the study:We aimed to highlight a rare anatomical variation involving the recurrent laryngeal nerve, and to emphasise its implications for thyroid surgery.Materials and methods:Over a period of 13 years, 993 patients underwent thyroid surgery; 1557 recurrent laryngeal nerves (887 on the right side) were exposed.Results:Three non-recurrent laryngeal nerves were found on the right side, associated with a retro-oesophageal subclavian artery. One case was suspected before surgery.Discussion:Several variations in the path and branches of the recurrent laryngeal nerve have been reported in the literature. The frequency of occurrence of a non-recurrent laryngeal nerve is about 1 per cent, for patients undergoing thyroid surgery. Other surgically relevant anatomical variations of the recurrent laryngeal nerve include associations with the inferior thyroid artery and the presence of nerve branches.Conclusion:The recurrent laryngeal nerve must be carefully dissected and totally exposed during thyroid surgery in order to best preserve its function. Moreover, the thyroid surgeon must be aware of the existence of anatomical variations, which are not as rare as one may think.

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The Recurrent Laryngeal Nerve in Relation to the Inferior Thyroid Artery in Adult Filipino Cadavers

Philippine Journal of Otolaryngology Head and Neck Surgery ◽

10.32412/pjohns.v26i2.569 ◽

2011 ◽

Vol 26 (2) ◽

pp. 13-17 ◽

Cited By ~ 2

Author(s):

Jacob S. Matubis ◽

Karen June P. Dumlao ◽

Ryner Jose C. Carrillo

Keyword(s):

Recurrent Laryngeal Nerve ◽

Thyroid Surgery ◽

Anatomical Variations ◽

The Philippines ◽

Laryngeal Nerve ◽

Inferior Thyroid Artery ◽

Laryngeal Nerves ◽

Recurrent Laryngeal Nerves ◽

The Right ◽

Relationship Of

Objective: To describe the anatomic relationship of the recurrent laryngeal nerve and the inferior thyroid artery in adult cadavers in the Philippines and to compare the proportions of these anatomic relationships with those reported in the foreign literature. Methods: Study design: Descriptive, cross-sectional Setting: University of the Philippines College of Medicine Anatomy Laboratory Subjects: Fifty-four (54) preserved cadavers (108 sides) dissected within a period from June 2008 to Aug 2010. The anatomy and position of both the right and the left recurrent laryngeal nerves (RLN) and inferior thyroid arteries (ITA) were noted. The RLN was further classified into 2 variations: non-branching or branching prior to insertion at the cricothyroid joint, under the inferior constrictor muscle. The ITA was also classified into non-branching and branching. The results were compared to two foreign studies using a Z-test for two proportions. Results: Fifty four (54) cadavers (108) sides were dissected. Among the cadavers, both the recurrent laryngeal nerves and inferior thyroid arteries had a maximum of two branches although both the RLNs and ITAs for both the right and left sides were mostly non-branching. The right side of one cadaver was noted to have both a branching RLN and a branching ITA. There were no non-recurrent laryngeal nerves seen among the 54 cadavers. For both left and right sides, the RLN was mostly dorsal to the ITA. Branching RLNs was mostly dorsal to a non-branching ITAs. Most of the non-branching RLNs were dorsal to the ITAs. Non-branching RLNs were usually dorsal to the ITA. The local patterns of the course of the RLN in relation to the ITA approximates those of Chinese where there is predominance of the RLN dorsal to the ITA but differs from those of Brazilians where the RLN is usually between ITA branches. Conclusion: There are multiple anatomical variations with regards to the relationship of the RLN and the ITA. The anatomic variation among Asians may be different from Brazilians. The surgeon’s knowledge of the possible various configurations of the RLN and ITA should be able to help in identification and preservation of the RLN and prevention of complications in thyroid surgery. Keywords: recurrent laryngeal nerve, inferior thyroid artery, thyroid surgery, Filipino cadavers, anatomical variations

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Thyroid tubercle of Zuckerkandl: anatomical and surgical experience from 79 thyroidectomies

The Journal of Laryngology & Otology ◽

10.1017/s0022215108004003 ◽

2008 ◽

Vol 123 (7) ◽

pp. 768-771 ◽

Cited By ~ 18

Author(s):

C Page ◽

P Cuvelier ◽

A Biet ◽

P Boute ◽

M Laude ◽

...

Keyword(s):

Thyroid Gland ◽

Recurrent Laryngeal Nerve ◽

Thyroid Surgery ◽

Anatomical Variation ◽

Lateral Lobe ◽

Anatomical Variations ◽

Anatomical Landmark ◽

Laryngeal Nerve ◽

Surgical Experience ◽

The Right

AbstractObjective:To highlight a poorly known anatomical variation of the lateral lobe of the thyroid gland, which can be useful in identifying the recurrent laryngeal nerve during thyroid surgery.Materials and methods:We performed a three-year prospective study of 79 thyroid surgery patients. Great attention was paid to anatomical variations of the thyroid gland (i.e. the presence or absence of a distinct tubercle of Zuckerkandl), the recurrent laryngeal nerve and the location of the parathyroid glands.Results:A total of 71 right lobectomies and 74 left lobectomies were performed. Five tubercles of Zuckerkandl were identified (7.04 per cent of cases) and were useful in detecting the recurrent laryngeal nerve (but only on the right side).Conclusion:The tubercle of Zuckerkandl is a poorly known and variable anatomical feature of the thyroid gland which may not, in fact, be so rare. It arises for embryological reasons, and it can be a reliable anatomical landmark for identifying the recurrent laryngeal nerve during thyroid surgery. It should be included in the Nomina Anatomica as the ‘processus posterior glandulae thyroideae’ described by Zuckerkandl.

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Relation of Nonrecurrent Laryngeal Nerve with Zuckerkandl’s Tubercle

Case Reports in Surgery ◽

10.1155/2020/2459321 ◽

2020 ◽

Vol 2020 ◽

pp. 1-3

Author(s):

Carlos Alberto Ferreira de Freitas ◽

Maria Margarida Morena Domingos Levenhagen ◽

Isabela Salvador Constantino ◽

Amauri Ferrari Paroni ◽

Marcelo Resende Martins

Keyword(s):

Ultrasound Examination ◽

Asymptomatic Patient ◽

Anatomical Variation ◽

Thyroid Tissue ◽

Anatomical Variations ◽

Thyroid Stimulating Hormone ◽

Laryngeal Nerve ◽

Nonrecurrent Laryngeal Nerve ◽

The Right ◽

Hypoechoic Nodule

The nonrecurrent laryngeal nerve (NRLN) is a rare anatomical variation of the recurrent laryngeal nerve (RLN) that may hinder the identification and preservation of this nerve during surgery and is associated with increased iatrogenic risks. Zuckerkandl’s tubercle (ZT) is considered a useful reference for locating the RLN during thyroid surgery. We report the case of an asymptomatic patient with a 23 mm uninodular goitre suspicious for cancer. Ultrasound examination showed a hypoechoic nodule with regular contours and microcalcifications. The patient had normal thyroid-stimulating hormone and thyroxine levels, and aspiration biopsy was suspicious for follicular cancer. She was treated with total thyroidectomy after the intraoperative examination confirmed the presence of a papillary thyroid carcinoma. The standard approach to the RLN below the inferior thyroid artery was used on both sides. The nerve displayed anatomical variation in the nonrecurrent form (NRLN) on the right side and was associated with another variation that was not found in the consulted literature. It was completely surrounded by thyroid tissue in the region of ZT, and the surgeon was forced to remove it from within the thyroid tissue. This combination of anatomical variations seems to be quite rare. Knowledge of the anatomy of the RLN and its variations, as well as its identification and careful dissection, is essential to avoid injury to the nerve during surgical procedures.

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Identifying Recurrent Laryngeal Nerve in Thyroid Surgery Using Relationship with Superior Parathyroid Gland and Tubercle of Zuckerkandl

Bengal Journal of Otolaryngology and Head Neck Surgery ◽

10.47210/bjohns.2015.v23i3.55 ◽

2015 ◽

Vol 23 (3) ◽

pp. 99-103

Author(s):

Somesh Mozumder ◽

Shirish Dubey ◽

Aniruddha Dam ◽

Anup Kumar Bhowmick

Keyword(s):

Prospective Study ◽

Recurrent Laryngeal Nerve ◽

Parathyroid Gland ◽

Thyroid Surgery ◽

Intimate Relationship ◽

Laryngeal Nerve ◽

Laryngeal Nerves ◽

Recurrent Laryngeal Nerves ◽

A Prospective Study ◽

Relationship Of

Introduction: Recurrent laryngeal nerves (RLN) are particularly prone to injury during thyroid surgeries due to its intimate relationship and proximity with the gland. Zuckerkandl’s tubercle (ZT) helps in preserving RLN intra operative. Material and Methods: A prospective study for identifying RLN in thyroid surgery using relationship with superior parathyroid gland and tubercle of Zuckerkandl was conducted on 50 thyroidectomy patients between August 2013 and February 2014. Results: In all cases ZT was identified. Temporary paralysis of RLN was seen in 3 (6%) cases and permanent paralysis in 2 (4%) of cases. Discussion: The site of greatest risk during thyroidectomy to the RLN is in the last 2-3 cm extralaryngeal course of the nerve. Relationship of recurrent laryngeal nerve with superior parathyroid gland and tubercle of Zukerkandl (ZT) is known. Conclusion: Use of ZT and superior parathyroids as a landmark allows safe dissection of RLN.

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Nonrecurrent Laryngeal Nerve in the Era of Intraoperative Nerve Monitoring

Advances in Medicine ◽

10.1155/2016/1606029 ◽

2016 ◽

Vol 2016 ◽

pp. 1-4 ◽

Cited By ~ 1

Author(s):

Emin Gurleyik ◽

Gunay Gurleyik

Keyword(s):

Early Stage ◽

Anatomical Variation ◽

Vocal Cord Palsy ◽

Laryngeal Nerve ◽

Proximal Point ◽

Nerve Monitoring ◽

Risk Of Injury ◽

Nonrecurrent Laryngeal Nerve ◽

The Right ◽

Intraoperative Nerve Monitoring

Nonrecurrent laryngeal nerve (non-RLN) is an anatomical variation increasing the risk of vocal cord palsy. Prediction and early identification of non-RLN may minimize such a risk of injury. This study assessed the effect of intraoperative neuromonitoring (IONM) on the detection of non-RLN. A total of 462 (236 right) nerves in 272 patients were identified and totally exposed, and all intraoperative steps of IONM were sequentially applied on the vagus nerve (VN) and RLN. Right predissection VN stimulation at a distal point did not create a sound signal in three cases (3/236; 1.27%). Proximal dissection of the right VN under IONM guidance established a proximal point, creating a positive signal. The separation point of non-RLN from VN was discovered in all three patients. Non-RLNs were exposed from separation to laryngeal entry. Positive IONM signals were obtained after resection of thyroid lobes, and postoperative period was uneventful in patients with non-RLN. Absence of distal VN signal is a precise predictor of the non-RLN. IONM-guided proximal dissection of the right VN leads to identification of the non-RLN. The prediction of non-RLN by the absence of the VN signal at an early stage of surgery may prevent or minimize the risk of nerve injury.

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Characteristic travelling patterns of non-recurrent laryngeal nerves

The Journal of Laryngology & Otology ◽

10.1017/s0022215114000978 ◽

2014 ◽

Vol 128 (6) ◽

pp. 534-539 ◽

Cited By ~ 14

Author(s):

K H Hong ◽

H T Park ◽

Y S Yang

Keyword(s):

Computed Tomography ◽

Recurrent Laryngeal Nerve ◽

Subclavian Artery ◽

Vocal Fold ◽

Laryngeal Nerve ◽

New Classification ◽

Laryngeal Nerves ◽

Brachiocephalic Trunk ◽

Recurrent Laryngeal Nerves ◽

The Right

AbstractBackground:The non-recurrent laryngeal nerve is subject to potential injury during thyroid surgery. Intra-operative identification and preservation of this nerve can be challenging. Its presence is associated with an aberrant subclavian artery and the developmental absence of the brachiocephalic trunk. This study aimed to evaluate the incidence of non-recurrent laryngeal nerves and present a new classification system for the course of these nerves.Methods:Non-recurrent laryngeal nerves were identified on the right side in 15 patients who underwent thyroidectomy. The incidence of non-recurrent laryngeal nerves (during thyroidectomy) and aberrant subclavian arteries (using neck computed tomography) was evaluated, and the course of the nerves was classified according to their travelling patterns.Results:The overall incidence of non-recurrent laryngeal nerves was 0.68 per cent. The travelling patterns of the nerves could be classified as: descending (33 per cent), vertical (27 per cent), ascending (20 per cent) or V-shaped (20 per cent).Conclusion:Clinicians need to be aware of these variations to avoid non-recurrent laryngeal nerve damage. A retroesophageal subclavian artery (on neck computed tomography) virtually assures a non-recurrent laryngeal nerve. This information is important for preventing vocal fold paralysis. Following a review of non-recurrent laryngeal nerve travelling patterns, a new classification was devised.

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Non-Recurrent Laryngeal Nerve

Polish Journal of Surgery ◽

10.1515/pjs-2015-0066 ◽

2015 ◽

Vol 87 (7) ◽

Cited By ~ 1

Author(s):

Grzegorz Buła ◽

Ryszard Mucha ◽

Michał Paliga ◽

Henryk Koziołek ◽

Zbigniew Niedzielski ◽

...

Keyword(s):

Recurrent Laryngeal Nerve ◽

Anatomical Variation ◽

Nodular Goiter ◽

Laryngeal Nerve ◽

Main Trunk ◽

Identification Process ◽

Toxic Nodular Goiter ◽

Recurrent Laryngeal Nerves ◽

The Right ◽

Irreversible Nature

Abstractwas to assess the frequency of non-recurrent laryngeal nerves (Non-RLN).A total of 6110 patients were operated in our hospital between 1 January 2005 and 31 December 2013 for various goiters (5429) and various types of hyperparathyroidism (618). Laryngeal nerve was exposed during operation in 1700 patients from superior aperture of the chest to superior aperture of the larynx. Identification process of RLN was started with dissecting inferior thyroid artery (ITA) and its junction with the nerve. Then main trunk of the nerve was exposed backwards till the region of superior aperture of the chest together with the end portion till the nerve outlet to the larynx.In the group of 1700 patients, RLN was exposed bilaterally in 1400 (82.4%) and unilaterally in 300 (17.6%). In the group of 3100 dissected RLNs the course of RLN was observed on the right side in 1710 patients and on the left in 1390. Irreversible nature RLN was shown in four cases (0.1%) – four women (02%) aged 42-55 (mean 49.3) – three operated for non-toxic nodular goiter and one for primary hyperparathyroidism. Each time the Non-RLN was seen on the right side. The other patients manifested recurrent character RLN. Moreover, interstitial course of RLN was found on the left side in one man.Non recurrent laryngeal nerve is a rare anatomical variation, occurring more frequently on the right side. Surgeon during surgery of the thyroid and parathyroid glands should be aware of its existence to avoid damage.

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Nonrecurrent laryngeal nerve-an anatomical deviation

International Journal of Otorhinolaryngology and Head and Neck Surgery ◽

10.18203/issn.2454-5929.ijohns20213301 ◽

2021 ◽

Vol 7 (9) ◽

pp. 1562

Author(s):

E. Sivakumar ◽

C. A. Swapna ◽

Lavanya Karanam

Keyword(s):

Thyroid Surgery ◽

Vocal Cord Palsy ◽

Needle Aspiration ◽

Laryngeal Nerve ◽

Nodular Goitre ◽

Complications Of Thyroidectomy ◽

Right Lobe ◽

Nonrecurrent Laryngeal Nerve ◽

Needle Aspiration Cytology ◽

The Right

Thyroidectomy is one of the most dispute and discussed surgery. Identification of recurrent laryngeal nerve is the most important step in this surgery. Among postop complications of thyroidectomy, the commoner is haematoma, transient hypocalcaemia and hoarseness. We report a rare case of nonrecurrent laryngeal nerve in a 25-year-old male with swelling in the right thyroid lobe. A 25-year-old male presented to the ENT OPD with complaints of swelling in thyroid region for 6 months with no other symptoms. On examination there was a 2×3 cm size nodule in the right lobe of thyroid. Rest of ORL examination was normal. On ultrasonogram there was an enlarged right lobe of thyroid with a nodular goitre. Fine needle aspiration cytology showed colloid goitre. Patient was planned for right hemithyroidectomy. Right side type 1 nonrecurrent laryngeal nerve was identified at the level of superior pole of thyroid branching from vagus and entering the larynx at the level of cricothyroid joint was identified intraoperatively. In conclusion, nonrecurrent laryngeal nerve though a very rare anomaly forms a crucial anatomical structure in thyroid surgery and is prone to injury. It is one of the preventable complications during thyroid surgery leading to postop vocal cord palsy. An in-depth anatomical knowledge and diligent surgical technique will help in identification and preservation of nonrecurrent laryngeal nerve.

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