ANATOMICAL STUDY OF VARIATIONS IN THE ORIGIN OF SUPERIOR THYROID ARTERY

Abstract

Background: The superior thyroid artery (STA) is the dominant arterial supply of the thyroid gland, larynx and the neck. Knowledge of these variations is crucial for decreasing morbidity during the surgeries. The present study was undertaken to evaluate the frequency of usual anatomical variations in the origin of STA in human cadavers. Method: The origin of STA was studied by dissecting hundred human carotid specimens obtained from the formalin embalmed cadavers who were allotted to the undergraduate students for dissection in the Department of Anatomy. Results: STA arose commonly from external carotid artery (ECA) in 71 cases (71%), arising directly from common carotid artery (CCA) in 24 (24%) cases whereas only in 5 specimens (5%) it was arising at the level of bifurcation of CCA. On the right side STA was originated from ECA in 31(43.7%) and on left side it was 40(56.3%). STA was originated at bifurcation level in 5(100%) cases on right side and on left side no case was observed (0%). On right side STA was originated from CCA in14 (58.3%) cases and on left side in 10(41.6%) cases. Conclusion: The wide range of variations of the STA on its origin, course, branching patterns and relationship with adjacent structures is a common phenomenon. Thus, the deep knowledge concerning the origin and branching pattern of STA is essential in enhancing precision and decreasing morbidity related to the surgical and interventional radiological head and neck procedures.