Anatomical Variations of the Carotid Triangle: A Systematic Review

The carotid triangle is located in the anterolateral neck region and holds significant anatomical relevance in clinical practice. It is delineated by specific muscles and contains essential vascular and neural structures that, with anatomical variations, have been reported across numerous studies. This review aims to address the current knowledge gap by systematically collecting and analyzing reported anatomical variations of arteries, veins, nerves, and muscles within the carotid triangle, which are critical for safe and effective surgical planning. A systematic review was performed using Scopus and PubMed for data from 2000 to 2025. The initial search produced 768 articles, of which 27 met the inclusion criteria for analysis. In total, 387 cases were examined (336 involving cadavers and 51 living patients), and the identified variations were categorized into five thematic groups: arteries and their branches, ansa cervicalis, internal jugular vein, hypoglossal nerve, and muscular variations. The most common variations pertained to the bifurcation level of the common carotid artery, the relationship between the internal and external carotid arteries, and the variable origins of the anterior branches of the external carotid artery, particularly the superior thyroid artery. Variations in other anatomical structures were noted less frequently. This study highlights the importance of ongoing documentation of anatomical variations, which remain underreported and inconsistently documented in the literature. The growing research interest reflects their clinical significance and reinforces the need to understand this variability for safer and more effective surgical practice.