scholarly journals Morphology and Functional Anatomy of the Recurrent Laryngeal Nerve with Extralaryngeal Terminal Bifurcation

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Fuat Cetin ◽  
Emin Gürleyik ◽  
Sami Dogan
Keyword(s):  
Motor Activity ◽  
Recurrent Laryngeal Nerve ◽  
Bifurcation Point ◽  
Thyroid Surgery ◽  
Functional Anatomy ◽  
Anatomical Variations ◽  
Laryngeal Nerve ◽  
Main Trunk ◽  
Anterior Branch ◽  
Intraoperative Nerve Monitoring

Anatomical variations of the recurrent laryngeal nerve (RLN), such as an extralaryngeal terminal bifurcation (ETB), threaten the safety of thyroid surgery. Besides the morphology of the nerve branches, intraoperative evaluation of their functional anatomy may be useful to preserve motor activity. We exposed 67 RLNs in 36 patients. The main trunk, bifurcation point, and terminal branches of bifid nerves were macroscopically determined and exposed during thyroid surgery. The functional anatomy of the nerve branches was evaluated by intraoperative nerve monitoring (IONM). Forty-six RLNs with an ETB were intraoperatively exposed. The bifurcation point was located along the prearterial, arterial, and postarterial segments in 11%, 39%, and 50% of bifid RLNs, respectively. Motor activity was determined in all anterior branches. The functional anatomy of terminal branches detected motor activity in 4 (8.7%) posterior branches of 46 bifid RLNs. The motor activity in posterior branches created a wave amplitude at 25–69% of that in the corresponding anterior branches. The functional anatomy of bifid RLNs demonstrated that anterior branches always contained motor fibres while posterior branches seldom contained motor fibres. The motor activity of the posterior branch was weaker than that of the anterior branch. IONM may help to differentiate between motor and sensory functions of nerve branches. The morphology and functional anatomy of all nerve branches must be preserved to ensure a safer surgery.

scholarly journals Clinical impacts of the Sudanese anatomical variations in a relation of the recurrent laryngeal nerve to the inferior thyroid artery

2020 ◽  
Vol 8 (2) ◽  
pp. 25
Author(s):  
Mohamed Elghazali Elhasan ◽  
Wael Mohialddin Doush
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Anatomical Variations ◽  
Cross Sectional Study ◽  
Laryngeal Nerve ◽  
Inferior Thyroid Artery ◽  
Parathyroid Glands ◽  
Main Trunk ◽  
Cross Sectional ◽  
Relationship Of ◽  
The Relationship

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.  

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

2011 ◽  
Vol 26 (2) ◽  
pp. 13-17 ◽  
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

scholarly journals Intraoperative Monitoring of the Recurrent Laryngeal Nerve during Thyroidectomy: A Standardized Approach (Part 1)

2011 ◽  
Vol 3 (3) ◽  
pp. 144-150 ◽  
Author(s):  
Henning Dralle ◽  
Antonio Sitges-Serra ◽  
Peter Angelos ◽  
Manuel C Durán Poveda ◽  
Gianlorenzo Dionigi ◽  
...  
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Thyroid Surgery ◽  
Superior Laryngeal Nerve ◽  
Surgical Anatomy ◽  
Laryngeal Nerve ◽  
Nerve Monitoring ◽  
Visual Identification ◽  
Current State ◽  
Monitoring Procedure ◽  
Intraoperative Nerve Monitoring

ABSTRACT One of the most feared complications in thyroid surgery is injury to the superior laryngeal nerve or recurrent laryngeal nerve. Neural identification during surgery is insufficient to assess nerve injury. Intraoperative nerve monitoring of the vagal nerve and recurrent laryngeal nerve during thyroid surgery is a new adjunct designed to allow better identification of nerves at risk and therefore reduce complications related to their injury. This new working tool does not substitute adequate surgical technique but merely provides the surgeon with an adjunct to routine visual identification and functional assessment. The use of nerve monitoring requires standardization of the monitoring procedure. Pursuant to this, we will discuss in two related articles the current state of the art standardized technique of nerve monitoring in thyroid surgery. The aim of part 1 is to provide a concise overview of nerve monitoring in thyroid surgery and its effectiveness. This will include a brief review of the surgical anatomy of the recurrent laryngeal nerve and the key landmarks used to identify the nerve during surgery. Part 2 will describe how to perform the standardized nerve monitoring in a step by step fashion during thyroid surgery which will diminish variable results and misleading information associated with a nonstandardized nerve monitoring procedure.

scholarly journals Anatomical Variations of Recurrent Laryngeal Nerve: The Danger in Thyroid Surgery

2019 ◽  
Vol 10 (01) ◽  
pp. 11-15
Author(s):  
Fatogoma Issa Koné ◽  
Siaka Soumaoro ◽  
Naouma Cissé ◽  
N’faly Konaté ◽  
Kassim Diarra ◽  
...  
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Thyroid Surgery ◽  
Anatomical Variations ◽  
Laryngeal Nerve

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

2008 ◽  
Vol 123 (7) ◽  
pp. 768-771 ◽  
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.

scholarly journals Comparison of Recurrent Laryngeal Nerve Identification Time in the Lower Central Triangle During Thyroid Surgery Using Neurophysiological Mapping and Monitoring

Medicina ◽  
2021 ◽  
Vol 57 (8) ◽  
pp. 748
Author(s):  
Eunhye Lee ◽  
Keunchul Lee ◽  
Hyeongwon Yu ◽  
Sujin Kim ◽  
Youngjun Chai ◽  
...  
Keyword(s):  
Recurrent Laryngeal Nerve ◽  
Vocal Cord ◽  
Thyroid Surgery ◽  
Vocal Cord Palsy ◽  
Laryngeal Nerve ◽  
Follicular Neoplasm ◽  
National University ◽  
Seoul National University ◽  
Definition Of ◽  
Intraoperative Nerve Monitoring

Background and Objectives: Preserving the recurrent laryngeal nerve (RLN) is important in thyroid surgery. However, no standardized surgical method for locating the RLN has been established. We defined a new anatomical definition termed “lower central triangle” (LCT) for consistent identification of RLN and used intraoperative nerve monitoring (IONM) to aid in identification and dissection of RLN. Materials and Methods: Patients undergone thyroidectomy were reviewed retrospectively in Seoul National University Bundang Hospital from January to September 2017. Patients with papillary thyroid carcinoma, follicular neoplasm, and Graves’ Disease were included while right side non-RLN in arteriosus lusoria, cancer invasion, pre-existing vocal cord palsy, or under the age of 18 were excluded. RLNs were tested with IONM within LCT consisting of the lower pole as the apex and the common carotid artery as the opposite side. The samples were divided into two groups, IONM and non-IONM. Results: Forty lobes in total were included, 22 in IONM group and 18 in non-IONM group. Groups were not significantly different in age, cancer proportion, and accompanying thyroiditis while sex and nodule size differed. RLN detection time was 10.43 sec shorter (p < 0.001), and confirmation time was 10.67 sec shorter (p = 0.09) in IONM group than in non-IONM group. Both right and left RLNs were located predominately in the middle of LCT. No transient or permanent vocal cord palsy occurred. Conclusions: While IONM is an appropriate aid for thyroidectomy, our approach using LCT to locate the RLN is a novel definition of anatomy that provides prompt identification of the RLN in thyroid surgery.

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