Relative Topography of Laryngeal Nerves for Surgical Cruciality: An Observational Cadaveric Study.

To observe and evaluate the intricrate relationship of recurrent laryngeal nerve (RLN) and external branch of superior laryngeal nerve (EBSLN) to various anatomical structures in the neck like the inferior thyroid artery (ITA), Berry's ligament (LB), Zuckerkandl's tubercle (ZT) and with the superior thyroid artery (STA) for the knowledge of surgical cruciality during surgeries for thyroid gland diseases. This cadaveric observational study was conducted in the department of Otorhinolaryngology and Head and Neck Surgery with logistic support from Department of Anatomy. Total of 40 fresh frozen latex injected cadavers neck dissection was performed to study anatomical variations of thyroid gland and its related vessels and nerves. All measurements were recorded using digital caliper sensitive to 0.01 mm and photographs were documented. Topography of RLN was studied in relation to ITA, LB and ZT. The RLN was predominantly a posterior relation of the ITA in 86.25%, was deep to LB in 46.25% and was related posterior to ZT in 80% of cadaver dissected. The EBSLN has a variable relation with STA which was observed to lie at a distance of < 1 cm from STA in 66.25%. The difference between left and right side was not found to be statistically significant in all parameters ( > 0.05). The awareness and appreciation of the intricate topographical relations and its variations reinforce the surgeons to be careful when performing surgical procedures in the central compartment of the neck which avoid complications.