Anatomical variations of the superior thyroid artery: A systematic review

•The superior thyroid artery is one of the main arteries that provide blood supply to the thyroid gland.•The most common variations of the superior thyroid artery have to do with its origin and its branches/distribution.•Knowledge of the anatomical variability of the superior thyroid artery is crucial for interventions regarding the visceral compartment of the neck. The superior thyroid artery (STA) is one of the main arteries that provide blood supply to the thyroid gland. It has a plethora of anatomical variations, and knowledge of its anatomy is necessary in procedures in this area. The aim of this review is to summarize and describe human studies (cadaveric and angiographic) that investigate the anatomical variations related to the STA. A systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed. A literature search in PubMed, and Embase databases was carried out. Original studies that investigated the origin of the STA and reported data on the variant arterial anatomy were considered, including only cadaveric and angiographic studies. A total of 34 studies (4048 heminecks in total; heminecks in each study: min: 25–max: 1280) were finally included. All studies provide details about sex [men/women ratio median (IQR): 2(1–5)] but none about age and 10 (29%) about nationality. STA morphological characteristics described in the included studies are origin, length, number of branches, distance from the carotid bifurcation and the vessel's diameter. The STA's anatomical features are subject to a non-negligible degree of variability. Our results should improve the awareness of anatomical variations of the STA, and eventually have an impact on the interventions regarding the visceral compartment of the neck in clinical practice.