Anatomical variability of the superior thyroid artery: a computed tomography-based study in a Polish population and a...

The superior thyroid artery (STA) shows considerable anatomical variability with important implications for thyroid and laryngeal surgery. Although the external carotid artery (ECA) is the most commonly reported origin, alternative origins and variable relationships with the external branch of the superior laryngeal nerve (EBSLN) may increase intraoperative risk. This study aimed to evaluate STA morphology using computed tomography angiography (CTA) and to integrate these findings with a global meta-analysis.

A retrospective CTA analysis of 157 hemi-necks was performed to assess STA origin and branching patterns. In parallel, a systematic review and meta-analysis were conducted according to PRISMA guidelines and registered in PROSPERO (CRD42023393213). Ninety-three studies (12,022 arteries) were included to evaluate STA origin, Cernea classification, trunk formation, arterial diameter, and vertical level relative to the thyroid cartilage. Random-effects and compositional meta-analytic models were applied.

In the CTA cohort, the STA most frequently originated from the ECA on the right side and from the carotid bifurcation (CB) on the left (p < 0.001). The meta-analysis confirmed ECA predominance (57.6%). Cernea types I and IIa were most prevalent. Trunk formation was uncommon (3.6%). The pooled radiologic STA diameter was 1.73 mm, and more than half of arteries originated above the thyroid cartilage.

Despite marked variability, STA morphology shows recurring overall patterns. Combined CTA-based and meta-analytic findings highlight the importance of standardized anatomical definitions and careful identification of vascular and neural structures to reduce surgical risk in anterior neck surgery.