Extralaryngeal division of the recurrent laryngeal nerve: A common and asymmetric anatomical variant
Mehmet Uludağ1, Gürkan Yetkin1, Ebru Şen Oran2, Nurcihan Aygün1, Fevzi Celayir1, Adnan İşgör3
Objective: Recognition of extralaryngeal branching of the recurrent laryngeal nerve is crucial because prevention of vocal cord paralysis requires preservation of all branches of the recurrent laryngeal nerve. We 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 94 patients who underwent thyroid or parathyroid surgery between September 2011 and May 2012.
Results: A total of 161 recurrent laryngeal nerves were examined (82 right, 79 left). Overall, 77 (47.8%) of 161 recurrent laryngeal nerves were bifurcated before entering the larynx. There were 36 (43.9%) branching nerves on the right and 41 (51.9%) branching nerves on the left, and there was no significant difference between the sides in terms of branching (p=0.471). Among 67 patients who underwent bilateral exploration, 28.4% were found to have bilateral branching, 40.3% had unilateral branching, and the remaining 31.3% had no branching. The median branching distance was 15 mm (5-60mm).
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
This study was presented at the XVI. Annual Meeting of the European Society of Surgery- ESS, 22-24 November 2012, İstanbul, Turkey.
Cite this paper as: Uludağ M, Yetkin G, Şen Oran E, Aygün N, Celayir F, İşgör A. Extralaryngeal division of the recurrent laryngeal nerve: a common and asymmetric anatomical variant. Turk J Surg 2017; 33: 164-168.
Ethics committee approval was received for this study from the ethics committee of Şişli Etfal Training and Research Hospital.
Written informed consent was obtained from patients who participated in this study.
Concept - M.U., A.İ.; Design - M.U., G.Y.; Supervision - M.U., G.Y.; Resource - M.U.; Materials - M.U., G.Y.; Data Collection and/or Processing - E.Ş.O., N.A., .FC.; Analysis and/or Interpretation - M.U., A.İ.; Literature Search - M.U., N.A.; Writing Manuscript - M.U.; Critical Reviews - A.İ.
No conflict of interest was declared by the authors.
The authors declared that this study has received no financial support.