scholarly journals Anatomical Variations of the Recurrent Laryngeal Nerve and Implications for Injury Prevention during Surgical Procedures of the Neck

Diagnostics ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 670
Author(s):  
Alison M. Thomas ◽  
Daniel K. Fahim ◽  
Jickssa M. Gemechu

Accurate knowledge of anatomical variations of the recurrent laryngeal nerve (RLN) provides information to prevent inadvertent intraoperative injury and ultimately guide best clinical and surgical practices. The present study aims to assess the potential anatomical variability of RLN pertaining to its course, branching pattern, and relationship to the inferior thyroid artery, which makes it vulnerable during surgical procedures of the neck. Fifty-five formalin-fixed cadavers were carefully dissected and examined, with the course of the RLN carefully evaluated and documented bilaterally. Our findings indicate that extra-laryngeal branches coming off the RLN on both the right and left side innervate the esophagus, trachea, and mainly intrinsic laryngeal muscles. On the right side, 89.1% of the cadavers demonstrated 2–5 extra-laryngeal branches. On the left, 74.6% of the cadavers demonstrated 2–3 extra-laryngeal branches. In relation to the inferior thyroid artery (ITA), 67.9% of right RLNs were located anteriorly, while 32.1% were located posteriorly. On the other hand, 32.1% of left RLNs were anterior to the ITA, while 67.9% were related posteriorly. On both sides, 3–5% of RLN crossed in between the branches of the ITA. Anatomical consideration of the variations in the course, branching pattern, and relationship of the RLNs is essential to minimize complications associated with surgical procedures of the neck, especially thyroidectomy and anterior cervical discectomy and fusion (ACDF) surgery. The information gained in this study emphasizes the need to preferentially utilize left-sided approaches for ACDF surgery whenever possible.

2011 ◽  
Vol 26 (2) ◽  
pp. 13-17 ◽  
Author(s):  
Jacob S. Matubis ◽  
Karen June P. Dumlao ◽  
Ryner Jose C. Carrillo

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


2020 ◽  
Vol 8 (2) ◽  
pp. 25
Author(s):  
Mohamed Elghazali Elhasan ◽  
Wael Mohialddin Doush

Background: Until recently, the knowledge of the anatomical variations in the relationship between the recurrent laryngeal nerve (RLN) and the inferior thyroid artery (ITA) combined with visual intraoperative RLN identification are essential for the protection of these life-important structures during surgical exposure and the mobilization of thyroid and parathyroid glands. This leads to the proper treatment of patients and improvement of the surgical techniques.Aim: To describe anatomical variations in the relationship of the recurrent laryngeal nerve to the inferior thyroid artery in the Sudanese population.Patients and methods: Following ethical committee approval, an observational descriptive prospective cross-sectional study in the period between March 2019 and February 2020, for anatomical variations in the relation of the recurrent laryngeal nerve to the inferior thyroid artery in seventy-two cervical sides of thirty-six well-dissected embalmed Sudanese cadavers. The RLN was investigated in three positions: posterior to the ITA main trunk, anterior to the ITA main trunk and between the ITA branches. Then, the results were analyzed according to the gender, age and dissection side.Results: We found that the anatomical variations were more frequent in males (97.2%) than females (2.8%). The age of these variations ranged between 31–45 years which represents (61.1%). On the right side of the neck, the commonest position of the RLN is posterior to the ITA (63.9%) followed by in decreasing order of frequency, the RLNs run between the ITA branches (30.6%) and anterior to the ITA (5.6%). On the left side of the neck, the commonest position of the RLN is posterior to the ITA (69.4%). It passed between the ITA branches in (30.6%) of specimens. There was no anterior location of the RLN to the ITA. Variations in a relationship of the RLN to the ITA on one side is significantly different from the opposite side.Conclusions: Although the risk of potential damage to the RLN during surgical neck procedures involving the thyroid gland and parathyroid glands is well recognized, pre-operative detailed surgeon’s knowledge for these frequent anatomical variations and the usage of the ITA as an anatomical landmark for intraoperative RLN recognition is important. This will lead to a reduction of iatrogenic RLN injury prevalence. Future studies are recommended to compare the findings on this cadaveric study with a larger sample size in the long-term period.  


2017 ◽  
Vol 5 (1) ◽  
pp. 2-4
Author(s):  
Trideep Pantha ◽  
N.N. Mathur ◽  
S. Bhandary

Objective: To determine the anatomic relationship of recurrent laryngeal nerve with inferior thyroid artery, tracheo-oesophageal groove and Berry’s ligament and to determine the thickness and terminal branching pattern of recurrent laryngeal nerve.Material and Methods: Descriptive prospetive study was conducted in the department of Otorhinolaryngology and Head and Neck surgery in BPKIHS, Dharan, between July 2008- June 2009 including all patients undergoing thyroidectomy and total laryngectomy during the study period.Result: RLN frequently passed behind the inferior thyroid artery and occupied the tracheo-oesophageal groove in the left side than on the right. The average diameter of the nerve was 1.88 mm and the nerve commonly terminated as a single trunk.Conclusion: The nerves were commonly found deep to the ITA (96.2% on left side and 88% on right). The segment of RLN vulnerable to surgical injury between the crossing point of ITA to its entry in the larynx was found to be 3.13 cm (SD=0.29cm). The average thickness of the nerve was 1.68mm however the thickness increased as the surgery progressed and at the end of surgery. All the RLNs on the left side were found completely within the TOG while some variations were seen on the right side.


2020 ◽  
Vol 7 (10) ◽  
pp. 3469
Author(s):  
Shah Urvin Manish ◽  
Boopathi Subbarayan ◽  
Saravanakumar Subbaraj ◽  
Tirou Aroul Tirougnanassambandamourty ◽  
S. Robinson Smile

The incidence of Non-recurrent laryngeal nerve (NRLN) is reported to be 0.6%-0.8% on the right side and in 0.004% on the left side. Damage to this nerve during thyroidectomy may lead to vocal cord complications and should therefore be prevented. A middle-aged woman with a nodular goiter who underwent subtotal thyroidectomy for multinodular colloid goiter. We encountered a non-recurrent laryngeal nerve on the right side in a patient during surgery. We were not able to find the inferior laryngeal nerve in its usual position using the customary anatomical landmarks. Instead, it was emerging directly from the right vagus nerve at a right angle and entering the larynx as a unique non-bifurcating nerve. Nonrecurrent inferior laryngeal nerve incidence is very rare, but when present, increases the risk of damage during thyroidectomy. Hence, it is very important to be aware of the anatomical variations of the inguinal lymph node (ILN) and the use of safe meticulous dissection while looking for the nerve during thyroidectomy. The use of Intra-operative neuro-monitoring (IONM) if available in thyroid surgery allows the surgeon to recognize and differentiate branches of the inferior laryngeal nerve (ILN) from sympathetic anastomoses, as well as NRLN during surgery.


2020 ◽  
pp. 014556132091898
Author(s):  
Ayad Ahmad Mohammed ◽  
Sardar Hassan Arif

Introduction: The recurrent laryngeal nerve gains its name because after branching from the vagus nerve, it turns superiorly (recur) around the subclavian artery on the right and around the ligamentum arteriosum on the left, the nonrecurrent nerve has a straight direct course to the larynx and doesn’t follow this course. It presents mostly on the right side. The presence of this variation places the nerve at higher risk of injury during neck surgery especially thyroid operations. Case Presentation: A 45-year-old lady presented with painless thyroid enlargement for 1 year. Thyroid examination showed a 3-cm firm nodule at the right thyroid lobe with normal thyroid function tests. Right thyroid lobectomy was done and the histopathology showed a benign follicular lesion. During surgery, we discovered 2 nonrecurrent laryngeal nerves at the right side which were arising from the vagus nerve and both were entering the larynx. Conclusion: Failure in identification of the nerve or overlooking the possibility of the non-recurrent laryngeal nerve may result in a serious sequelae of nerve damage, ipsilateral injury may lead to permanent hoarseness and bilateral injury may result in severe dyspnea or aphonia. Currently, there are 3 types of nonrecurrent laryngeal nerve courses. Type 1 passes near to the superior thyroid vessels. Type 2 (2A) passes parallel to the inferior thyroid artery and has a transverse course above it. Type 3 (2B) passes parallel to the inferior thyroid artery and transversely between branches of or under the inferior thyroid artery, we can add to this classification type 4, which are 2 nonrecurrent laryngeal nerves (double nerves) passing above and parallel to the inferior thyroid artery.


2000 ◽  
Vol 55 (6) ◽  
pp. 195-200 ◽  
Author(s):  
Bernardo Almeida Campos ◽  
Paulo Roberto Ferreira Henriques

The anatomical relationship between the recurrent laryngeal nerve (RLN) and the inferior thyroid artery (ITA) was studied in 76 embalmed corpses, 8 females and 68 males. In both sexes, the RLN lay more frequently between branches of the ITA.; it was found in this position in 47.3% of male corpses and 42.8% of female ones. On the right, RLN was found between branches of the ITA in 49.3% of the cases, anterior to it in 38.04%, and posterior in 11.26%. On the left, the RLN lay between branches of the ITA in 44.45%, posterior to the ITA in 37.05%, and anterior to it in 18.05% of the cases. In 62.68% of the cases, the relationship found on one side did not occur again on the opposite side. There was a significant difference (p<0.05) in the distribution of the 3 types of relationships between the RLN and the ITA, on the right and on the left. Racial variations could contribute to an explanation of the differences observed by authors of different countries in the relationship between the RLN and the ITA.


Head & Neck ◽  
2016 ◽  
Vol 39 (1) ◽  
pp. 177-186 ◽  
Author(s):  
Brandon Michael Henry ◽  
Jens Vikse ◽  
Matthew J. Graves ◽  
Silvia Sanna ◽  
Beatrice Sanna ◽  
...  

2008 ◽  
Vol 123 (7) ◽  
pp. 768-771 ◽  
Author(s):  
C Page ◽  
P Cuvelier ◽  
A Biet ◽  
P Boute ◽  
M Laude ◽  
...  

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.


2020 ◽  
Vol 22 (2) ◽  
pp. 60-65
Author(s):  
Muhammad Ali Azad ◽  
AKM Asaduzzaman ◽  
Mohammad Delwar Hossain ◽  
Faysal Bin Mohsin ◽  
Abdullahis Safi

Introduction: Thyroid surgery is a common modality of treatment for both benign and malignant thyroid disorders.Relationship between inferior thyroid artery (ITA) and recurrent laryngeal nerve (RLN) is crucial in preservation of recurrent laryngeal nerve. Thorough anatomical knowledge and meticulous surgery will ensure the integrity of recurrent laryngeal nerve. Objective: The purpose of this study is to observe the anatomical position of recurrent laryngeal nerve in relation to inferior thyroid artery which will eventually lead to identification of recurrent laryngeal nerve peroperatively. Methods: A cross sectional retrospective study was conducted during the time period of 1st January 2013 to 31st December 2015 in Combined Military Hospital, Dhaka among 200 patients who had undergone thyroidectomy. Results: In this series on the right side 71.8% cases RLN was dorsal to ITA, 21.7% cases it was ventral and in 6.5% cases RLN runs in between the branches of ITA. In case of left side 74.5% cases RLN was dorsal to ITA, 22.5% cases it was ventral and in 3% cases RLN runs in between the branches of ITA. Conclusion: Usually RLN runs dorsal to ITA. In left side it is deeper and in case of right side it is more superficial. RLN may pass through the branches of ITA, but it is not very common. Bangladesh J Otorhinolaryngol; October 2016; 22(2): 60-65


2021 ◽  
Vol 18 (1) ◽  
pp. 7-12
Author(s):  
Md Rabiul Islam ◽  
Tahmina Begum ◽  
Nazrul Islam ◽  
Md Moshabbirul Islam

Background: Recurrent laryngeal nerve is varied anatomically with inferior thyroid artery. Objective: The purpose of the present study was to observe the anatomical variation of recurrent laryngeal nerve with inferior thyroid artery among Bangladeshi people. Methodology: This comparative cross-sectional study was conducted in the Department of Otolaryngology and Head-Neck surgery at Sylhet MAG Osmani Medical College Hospital, Sylhet, Bangladesh from January 2004 to December 2004 for a period of one (01) year. Patients whose recurrent laryngeal nerve was identified during thyroidectomy due to various pathological conditions of thyroid gland were selected as group I. Again, the dead body which were undergone dissection were designated as group II. All the patients whose recurrent laryngeal nerve and inferior thyroid artery were identified during total, near total, sub-total, hemithyroidectomised or lobectomised were included in this study. Result: A total number of 32 patients were recruited for this study. On the left side nerve was found anteriorly in 2(10.53%), in between in 4(21.05%) and posteriorly in 13(68.42%). On the right side-nerve was found anteriorly in 7(30.43%), in between in 6(26.09%) and posteriorly in 10(43.48%). In this series nerve was seen posterior relation more than other two relations and anterior relation more on right side whereas posterior relation on left side, anterior relation more than in between relation on right side but reverse on left side. In group II On the left side nerve was found anteriorly in 2(6.25%), in between in 6(18.75%) and posteriorly in 24(75%). On the right side-nerve was found anteriorly in 8(25%), in between in 9(28.12%), and posteriorly in 10(46.88%). Conclusion: In conclusion each recurrent laryngeal nerve lies posterior to the inferior thyroid artery in the majority of the occasions whereas the nerve lies anterior to the branches of the inferior thyroid artery less commonly except right side of both study group. Journal of Science Foundation, January 2020;18(1):7-12


Sign in / Sign up

Export Citation Format

Share Document