A rare variation of five major vessels arising from the aortic arch with an absence of brachiocephalic trunk

Abstract

The most common variations of the aortic arch branching pattern usually involve the distance between the vessels arising from it and their dimensions. Changes in the number of vessels originating from the aortic arch, ranging from one to four or more major vessels instead of the classical three vessels as independent branches, are uncommon. Incidents of branching patterns involving four independent vessels arising from the aortic arch are rare, and reports of five or six independent vessels are extremely rare. We report on a case of an absent brachiocephalic trunk associated with an aberrant right subclavian artery and five distinct major vessels arising directly from the aortic arch in a South African male. Although most congenital vascular variations are incidental findings on angiographic images, some have also been associated with cerebrovascular diseases such as cerebral aneurysms. In addition, knowledge of these rare variations is of diagnostic importance as their presence may increase the difficulty and alter the specificity of vascular procedures performed using endovascular and open techniques.

Keywords: Aberrant right subclavian artery; Aortic arch; Brachiocephalic trunk; Computed tomography angiography; Vertebral artery.

Fig. 1

A 3D-CTA reconstructed image of the aortic arch (white star) showing the anterolateral view of the arch of the aorta and its branches. An absent brachiocephalic trunk was noticed. The first branch of the arch of the aorta is the right common carotid artery (RCCA-green arrow). The right vertebral artery arises from the anteromedial part of the RCCA (white arrow). The RCCA was followed by the left common carotid artery (LCCA-purple arrow). The left VA directly originates from the arch of the aorta (yellow arrow). The left subclavian artery (LSCA) is the last branch from the anterior view (blue arrow). An aberrant right subclavian artery (RSCA) (arising from the posterior aspect of the arch of the aorta took its origin proximal to the origin of the left subclavian artery (distal portion of the AA) (red arrow). B 3D-CTA reconstructed image of the aortic arch (white star) showing the posterior view of the arch of the aorta and its branches. An absent brachiocephalic trunk was noticed. The first branch of the arch of the aorta is the right common carotid artery (RCCA-green arrow). The right vertebral artery arises from the anteromedial part of the RCCA (white arrow). The RCCA was followed by the left common carotid artery (LCCA-purple arrow). The left VA directly originates from the arch of the aorta (yellow arrow). The left subclavian artery (LSCA) is the last branch from the anterior view (blue arrow). An aberrant right subclavian artery (RSCA) (arising from the posterior aspect of the AA) took its origin proximal to the origin of the left subclavian artery (distal portion of the AA) (red arrow). C 3D-CTA volume reconstruction of the right ICA run showing the superiorly pointing, posterior communicating artery aneurysm (red arrow) arising from the medial wall of the ICA (green arrow).