Collateral circulation in subclavian stenosis or atresia: Angiographic demonstration of retrograde vertebral-subclavian flow in two cases with right aortic arch

Angiographic evidence of retrograde vertebrosubclavian flow in 2 children is presented. Both have identical congenital anomalies, namely, right aortic arch, aortic diverticulum, left subclavian atresia in one and severe stenosis of the same artery in the other. Although one of these children has what might be the onset of claudication in the arm, symptoms of cerebral ischemia, i.e., “subclavian steal” are absent. Additional blood flow to the affected arm from the cervical collateral vessels and the absence of cerebral atherosclerosis may be factors responsible for the absence of symptoms in these children. It is suggested that in some adults with the “subclavian steal” the arterial stenosis is of congenital origin. The importance of inequality of the radial pulses and blood pressures, a sign found in both adults and children, is emphasized. Clinical differentiation of the sign, also present in coarctation of the aorta with stenosis of the left subclavian artery and the supravalvular aortic stenosis syndrome, is discussed. The anomalies associated with a right aortic arch can be predicted from plain chest roentgenograms with barium swallow by noting the side (right or left) on which the arch and the first part of the aorta descend and the size and shape of the esophageal impressions in the posteroanterior and left anterior oblique views.