Morphologic features of the aortic arch and its branches in the adult Chinese population

Objective: The prevalence of various aortic arch branching patterns has not been established in Chinese people. Little is known regarding the underlying associations among age, sex, aortic arch type, branching variants, and even vertebral artery (VA) dominance (VAD) or VA hypoplasia (VAH). Thus, this study aimed to determine the prevalence of variations in aortic arch branching and types of arches in a Chinese population and to evaluate the associations among age, sex, aortic arch type, branching variants, and asymmetric VAs. Methods: This retrospective study included 2370 patients (1348 men) who underwent thoracic enhanced computed tomography. Two observers independently evaluated the computed tomography images for aortic arch branching patterns, arch type, and the V1 segment caliber of the VA. Results: A normal aortic arch branching pattern, classified as type A, was found in 1985 patients (83.8%). The remaining 385 patients (16.2%) with variations in arch branching were classified as types B through E according to the prevalence and general morphology of the aortic arch. The male-to-female ratio in patients with arch branching types B through E was significantly lower than that in patients with the normal type A pattern (0.87 vs 1.43; P < .01). We further identified that a steep aortic arch was significantly associated with age and sex. From the types I to III arch, the mean age was 55.4 +/- 12.3, 60.9 +/- 10.7, and 65.2 +/- 9.9 years, and the male-to-female ratio was 685/653, 480/297, and 183/72, respectively. We also found that the left VA, which directly originated from the arch, was associated with right VAD and left VAH. Conclusions: The incidence of variations in arch branching is higher in women. Advanced age and male sex are risk factors for a steep aortic arch. The left VA directly originating from the arch is strongly correlated with right VAD and left VAH.