Morphometry of the aortic arch and its branches. A computed tomography angiography-based study

Background: The current study aims to determine the prevalence of variations of the aortic arch using computed tomography angiography (CTA), as well as morphometries and gender correlations. Materials and methods: A retrospective, transverse, observational and descriptive study of 220 CTA was performed. The branching pattern, most cranial vertebral level of the aortic arch, area of the proximal, middle and distal segments of the arch, area of each branch, and the path of atypical arteries were recorded. Results were analysed and stratified by gender. Results: The typical aortic arch branching pattern was present in 77.7% without statistical significance between genders. The most common variant was a two-branch pattern with a common trunk and a left subclavian (13.6%), followed by a typical branching pattern with an added left vertebral artery (7.3%). T3 was the most frequent cranial level (32.3%), followed by T2–T3 (26.8%), and T3–T4 (23.2%). The mean areas of the aortic arch were 685.5 ± 183.9, 476.1 ± 124.1, and 445.0 ± 145.1 mm2 for the proximal, middle and distal segments, with statistical difference between men and women in the middle and distal segments. Three paths of atypical arteries were identified: bifurcated vertebral artery (0.5%), aberrant right subclavian artery (0.5%), and left subclavian ostium obstruction (0.5%). Conclusions: Mexican population has one of the highest prevalence of variations in the aortic arch branching pattern. The high probability of finding these should be taken into consideration when assessing patients. A standardised classification method would contemplate future un-reported findings, without causing confusion by the different numbers assigned by each author.