Variations in Origins of External, Internal Carotid Artery and Superior Thyroid Artery Branching Pattern: A Cadaveric Study

Abstract

Introduction: The rich vascularity of most parts of the head and neck is mainly maintained by the carotids and their branches. However, variations in the External Carotid Artery (ECA) and Superior Thyroid Artery (STA) can pose risks during neck surgeries. Aim: This study aimed to examine relationship of ECA at point of origin and variations in the origin of superior thyroid artery. Materials and Methods: A cross-sectional study was conducted at the Department of Anatomy, Government Medical College, Kota, Rajasthan, India. Fifty common carotid arteries were obtained from 20 adult human cadavers and five sagittal sections of head and neck specimens. The specimens were dissected bilaterally, resulting in a total of 50 carotids observed. Data analysis was performed using SPSS software version 25. Results: In 86% of the specimens, the ECA originated at the upper border of the thyroid cartilage, while in 14% of the specimens, it was at a higher level. Transposition of the ECA laterally was observed in 4% of the specimens, and medial transposition was observed in 96% of the specimens. The STA originated from the ECA in 76% of the specimens, from the carotid bifurcation in 16% of the specimens, and from the Common Carotid Artery (CCA) in 8% of the specimens. Conclusion: The anatomical level of the CCA bifurcation is crucial clinically and surgically. These findings contribute to our understanding of the vascular anatomy of the carotid triangle, aiding students, radiologists, and surgeons in preventing complications and improving head and neck surgeries.

Keywords

• anatomy
• carotid bifurcation
• common trunk
• neck surgeries