Surgical anatomy of the Internal Branch of superior laryngeal

INTRODUCTION AND OBJECTIVE: Nervus laryngeus superior is separated from the ganglion vagal inferior of the nervus vagus and pierces the vagina carotica by crossing the artery carotis interna forward from the deep down and inside. At the cornu majus level of the hyoid bone, the superior laryngeal nerve is divided into a thin branch, the ramus externus, and the ramus internus, a thick branch. The aim of this study is to investigate the surgical anatomy of the ramus internus of the nervus laryngeus internus. MATERIALS AND METHOD: Patients aged 36-90 years who underwent total laryngectomy operation with the diagnosis of laryngeal carcinoma participated in the study. Fifteen patients who underwent total laryngectomy operation between June 2015 and November 2016 were included in the study. A total of 29 superior laryngeal nerves (NLS) of 15 patients were studied. Position of nerve was photographed before thyrohyoid membrane was passed during dissection. The relationship and course of NLS with arteria laryngea superior were observed. The distance to some adjacent formations and branching variants were examined during the course of the nerve. RESULTS: Of the total 29 NLSri, 17 were divided into three branches and 12 by two branches. In all cases except for the right neck of a case, the NLSri was branched after passing the thyrohyoid membrane in both necks. The NLSri's MTH crossing point was a mean of 12.0 ± 2.61 mm (6-16 mm) from the upper border of the thyroid cartilage. NLSri's thyrohyoid membrane crossing point was a mean distance of 9,34 ± 1,65 (6-12) mm from the lower border of os hyoidea CONCLUSION: Our study reported that the NLSri's branching pattern after MTH was the highest. Unlike other studies, in our study, no NLSri was on the superior laryngeal artery. Key words: Nervus laryngeus superior ramus internus, Membrana thyrohyoidea, Arteria laryngea superior, Nervus laryngeus superior, Nervus vagus.