Emerging patterns of the human superior thyroid artery and review of its clinical anatomy

Abstract

There is wide variability of the location of the superior thyroid artery (STA). Our purpose was to describe variations of the STA origin, with great respect to different anatomical patterns which could be observed in humans. The material was 68 formalin-embalmed adult cadavers of both sexes (45-70-year-old). Methodologically, we dissected the neck region bilaterally and focused on studying the external carotid artery (ECA) branches, especially the STA emerging pattern. We also measured the distance of the STA origin from the common carotid artery (CCA) bifurcation (using the latter as a landmark). Based on our results we categorized the STA emerging pattern into three major types A, B and C according to its origin (which was CCA, ECA and CCA bifurcation, respectively). Regarding type B, we found that the left STA arises approximately 2mm closer to the CCA bifurcation compared to the right STA (p<0.05). The STA is a carotid branch with variable origin, which can be CCA, ECA or CCA bifurcation. It is also an artery of great clinical importance in head and neck surgery. The present study provided data of the STA emerging patterns, as well as a review of its clinical anatomy.