Surgical anatomy of external branch of superior laryngeal nerve (EBSLN) in thyroid surgery

Abstract

Aim and objective: To study the anatomic variations of the external branch of superior laryngeal nerve and to propose a systemic approach to identification and preservation of this nerve during thyroid surgery. Methods: In the present study total 90 cases of thyroid diseases were treated with surgery, in the department of ENT at a tertiary care hospital, over a period of 2 years. Hemithyroidectomy was the most common operative procedure implemented in 63 patients (70%) among which right sided was more common (58.7%). Next common procedure performed was that of total thyroidectomy in 27 patients (30%). The position of EBSLN was classified according to the Cerneas classification. Results: A total number of 88 EBSLN were identified and majority of EBSLN were found to be type II a variant i.e 59% followed by type I variant (25%) and type II b variant (16%). In about 18 patients, EBSLN was not identified. Conclusion: In our study the surgeons can be sensitized about EBSLN anatomic variations, anatomic variation taken into consideration to identify EBSLN during thyroid surgery. Preservation of the EBSLN maintains optimal function of the larynx.