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
References
- International Evidence-Based Anatomy Working Group, 12 Kopernika St, 31-034 Krakow, Poland
- Department of Anatomy, Jagiellonian University Medical College,12 Kopernika St, 31-034 Krakow, Poland
- Asgharpour E, Maranillo E, Sañudo J et al (2012) Recurrent laryngeal nerve landmarks revisited. Head Neck 34:1240–1246
- Beneragama T, Serpell JW (2006) Extralaryngeal bifurcation of the recurrent laryngeal nerve: a common variation. ANZ J Surg 76: 928–931
- Nemiroff PM, Katz AD (1982) Extralaryngeal divisions of the recurrent laryngeal nerve. Surgical and clinical significance. Am J Surg 144:466–469
- Salama AB, McGrath P (1992) Recurrent laryngeal nerve and the posterior fascial attachment of the thyroid gland. Aust N Z J Surg 62:444–449
- Schweizer V, Dörfl J (1997) The anatomy of the inferior laryngeal nerve. ClinOtolaryngol Allied Sci 22:362–369
- He X, Sun J, Ye C et al (2000) Anatomic study on the nervous distribution of the human. J Clin Otorhinolaryngol Head Neck Surg 14:387–389.
- Makay O, Icoz G, Yilmaz M et al (2008) The recurrent laryngeal nerve and the inferior thyroid artery—anatomical variations during surgery Langenbecks Arch Surg 393:681 685
- Kandil E, Abdelghani S, Friedlander P et al (2011) Motor and sensory branching of the recurrent laryngeal nerve in thyroid surgery. Surgery 150:1222–1227
- Cernea CR, Hojaij FC, De Carlucci D Jr, Gotoda R, Plopper C, Vanderlei F, Brandao LG. Recurrent laryngeal nerve: a plexus rather than a nerve? Arch Otolaryngol Head Neck Surg 2009;135:1098-102
- Sun SQ, Zhao J, Lu H, He GQ, Ran JH, Peng XH. An anatomical study of the recurrent laryngeal nerve: its branching patterns and relationship to the inferior thyroid artery. Surg Radiol Anat 2001; 23:363-9.
- Katz AD, Nemiroff P. Anastamoses and bifurcations of the recurrent laryngeal nerve–report of 1177 nerves visualized. Am Surg 1993; 59: 188-91.
- Rustad WH. Revised anatomy of the recurrent laryngeal nerves: surgical importance, based on the dissection of 100 cadavers. J Clin Endocrinol Metab 1954;14:87-96
- Sunderland S, Swaney WE. The intraneural topography of the recurrent laryngeal nerve in man. Anat Rec 1952;114:411-26
- Sanders G, Uyeda RY, Karlan MS. Non-recurrent inferior laryngeal nerves and their association with a recurrent branch. Am J Surg. 1983;146(4):501-503.
- Delbridge L. Total thyroidectomy: the evolution of surgical technique. ANZ J Surg 2003;73:761-8.
- Hermann M, Alk G, Roka R, Glaser K, Freissmuth M. Laryngeal recurrent nerve injury in surgery for benign thyroid diseases: effect of nerve dissection and impact of individual surgeon in more than 27,000 nerves at risk. Ann Surg 2002;235:261-8.
- Thomusch O, Machens A, Sekulla C, Ukkat J, Lippert H, Gastinger I, et al. Multivariate analysis of risk factors for postoperative complications in benign goiter surgery: prospective multicenter study in Germany. World J Surg 2000; 24:1335-41.
- Serpell JW, Yeung MJ, Grodski S. The motor fibers of the recurrent laryngeal nerve are located in the anterior extralaryngeal branch. Ann Surg 2009;249:648-52.
Corresponding Author
Dr Suresh Kumar Yadav
Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
DOI: https://dx.doi.org/10.18535/jmscr/v7i5.67
