Altered Cerebral Collateralization in Patients with Left Brachiocephalic Trunk Occlusion and a Right Descending Aorta

Introduction

A right aortic arch with a left brachiocephalic trunk is a very rare abnormality in the development of the aortic arch and its branches. It accounts for only 0.1 % of all aortic arch abnormalities and is associated in 95 % of all cases with cyanotic heart diseases. At a young age, the latter patients often exhibit pectanginal symptoms (Das SK et al. Byrom Eur J Vasc Endovasc Surg 2005; 30: 48–51). The clinical presentation of the remaining 5 % is non-specific and can result in a subclavian steal syndrome. An association with a patent ductus arteriosus, a left brachiocephalic trunk or other cardiac abnormalities is very common (Singh B. Clin Anat 2001; 14: 47–51). In the case of occlusion of the left brachiocephalic trunk, reactivation of embryonic segmental arteries may result in atypical patterns of collateral vessel pathways with altered cerebrovascular hemodynamics.

In this paper we employ a battery of noninvasive neuroimaging techniques, color-coded duplex sonography, magnetic resonance angiography (MRA) and computed tomographic angiography (CTA) to characterize the hemodynamic situation in two patients with occlusion of an isolated left brachiocephalic artery, a right aortic arch and extensive segmental collateral vessel formations.