Anatomical variations of the superior thyroid and superior laryngeal arteries.

BACKGROUND There are known to be variations in the origins of the superior thyroid artery (STA), an important surgical landmark, and 1 of its branches, the superior laryngeal artery (SLA). METHODS Three hundred thirty human embalmed heminecks were dissected. The results of previous studies were reviewed, and a meta-analysis is presented. RESULTS Four different origins for the STA were found. The most frequent was type I, from the carotid bifurcation (49%). Four different origins were also found for the SLA being the most frequent the type I in which the artery arose from STA (78%). The mean external diameters of STA and SLA were 0.26 and 0.20 cm, respectively, with no statistically significant differences by side or sex. CONCLUSION Variations in the origin of STA and SLA from the carotid arterial tree and the similarity of their diameters mean that there is a significant possibility of their misidentified during surgery.