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Category: Volume 07 Issue 05 May 2019
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Title: Study of Extra laryngeal Branching of Recurrent Laryngeal Nerve in Thyroid Surgery

Authors: Dr Sunil Kumar Samdani, Dr Ram Kalyan Meena

 DOI: https://dx.doi.org/10.18535/jmscr/v7i5.67

Abstract

Objective: Recognition of extralaryngeal branching of the recurrent laryngeal nerve is essential because prevention of vocal cord functions requires preservation of all branches of the recurrent laryngeal nerve. We have assessed the prevalence of extralaryngeal branching of the recurrent laryngeal nerve and the median branching distance from the point of bifurcation to the entry point of the nerve into the larynx.

Material and Methods: Prospective operative data on recurrent laryngeal nerve branching were collected from 90 patients who underwent thyroid surgery between April 2017 to March 2018.

Results: A total of 113 recurrent laryngeal nerves were examined (60 right, 53 left). Overall, 65(57.5%) of 113 recurrent laryngeal nerves have extralaryngeal branching before entering the larynx. There were 37 (61.66%) branching nerves on the right and 28 (52.83%) branching nerves on the left. There was 35(58.33%) recurrent laryngeal nerve had bifurcation and 2(3.33%) recurrent laryngeal nerve had trifurcation in right side. There was no trifurcation found in left recurrent laryngeal nerve. Among 23(46RLN) patients who underwent bilateral exploration, 9 patient 39.13% (18RLN) were found to have bilateral branching, 15.21%(7 RLN) had unilateral branching and the remaining 45.65%(21RLN) had no branching. The median branching distance was 10 mm (5-20mm).

Conclusion: Extralaryngeal division of recurrent laryngeal nerve is a common and asymmetric anatomical variant. These variations can be easily recognized if the recurrent laryngeal nerve is identified at the level of the inferior thyroid artery and then dissected totally to the entry point of the larynx. Inadvertent division of a branch may lead to vocal cord palsy postoperatively, even when the surgeon believes the integrity of the nerve has been preserved.

Keywords: Thyroid surgery, anatomic variations, recurrent laryngeal nerve, laryngeal branches, vocal cord palsy

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Corresponding Author

Dr Suresh Kumar Yadav

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