Right External Carotid Artery Originated Right Superior Thyroid Artery in Cadavers of a Medical College in Nepal: A Descriptive Cross-sectional Study

INTRODUCTION: External carotid artery originated superior thyroid artery are frequently documented in classical anatomical, surgical and radiological textbooks. Knowledge of anatomical variations, proper identification of superior thyroid arteries is very important to avoid major complications during and after neck surgeries. The aim of the study is to find out the prevalence of right superior thyroid artery originating from right external carotid artery in cadavers of a Medical College in Nepal. METHODS: A descriptive cross-sectional study was carried out at the department of anatomy in Universal College of Medical Sciences, Bhairahawa, Nepal from October 2020 to January 2021 after ethical clearance from the same institution (IRC UCMS, Ref: UCMS/IRC/078/20). Variations in origin of superior thyroid arteries were observed, recorded and photographed. Convenient sampling method was used. Data was analyzed using Microsoft Excel 2016. Point estimate at 90% Confidence Interval was calculated along with frequency and percentage. RESULTS: Out of 30 right superior thyroid arteries of 30 cadavers, 27 (90%) at 90% Confidence Interval (80.22-96.44) originates from right external carotid artery. CONCLUSIONS: In our study we observed that almost nine tenths of right superior thyroid arteries originated from the right external carotid artery which was relatively high in comparison to other studies. Thus, Extensive knowledge of variations in origin of superior thyroid artery is important for surgeons prior to various interventional surgeries.