Anatomical variability in the structure of the arch and thoracic aorta and its influence on aorta related pathological conditions

Aim. Assessment of normal and variant aortic arch anatomy in patients with type A aortic dissection and aneurysm of the arch and descending thoracic aorta. Methods. We retrospectively studied computer tomography (CT) data of chest organs with contrast in patients who underwent reconstruction of the aortic arch in type I aortic dissection according to DeBakey classification (n = 61) and resection of the aortic arch and descending thoracic aorta aneurysm (n = 14) at the Meshalkin National Medical Research Center, Novosibirsk, Russian Federation. The control group included patients without aortic arch pathology (n = 52). To identify relationships between the anatomical type of aortic arch and the risk of aortic pathology development, univariate and multivariate binary logistic regression analyses were used. Results. Our analysis revealed four types of aortic arch anatomy. Normal aortic arch anatomy occurred in 66.1 % of patients (n = 84), the proportion of abnormalities of the left common carotid artery was 30 % (bovine aortic arch occurred in 15 %, and the same site of origin of left common carotid artery and brachiocephalic trunk occurred in 15 %). Divergence of the left vertebral artery from the aortic arch between the left common carotid and left subclavian arteries occurred in 3.1 % (n = 4), and the combination of "bovine trunk” and divergence of the left vertebral artery from the aortic arch was detected in 0.8 % patients (n = 1). Logistic regression analyses revealed no statistically significant relationships between variant aortic arch anatomy and the development of type A aortic dissections and aortic arch aneurysms. The presence of the common origin of brachiocephalic trunk and left common carotid artery was associated with a reduced risk of acute aortic dissection type I by 89 %, or an OR of 0.11 (95% CI: 0.03-0.46) (p = 0.002). Conclusion. Our data will help with future planning surgical interventions on the aortic arch and descending thoracic aorta. Received 17 June 2020. Revised 16 July 2020. Accepted 17 July 2020.