Origin of Bilateral Subclavian Arteries From the Site of Coarctation: A Rare Configuration

Abstract

A 4-year-old male child presented with pain in his bilateral upper limbs. Pulses were feeble in all 4 limbs. Blood pressures recorded in the right upper limb, left upper limb, right lower limb, and left lower limb were 80/60 mm Hg, 84/54 mm Hg, 70/52 mm Hg, and 68/50 mm Hg, respectively. Transthoracic echocardiography established the diagnosis of coarctation of aorta, and the patient was referred for cardiac computed tomographic angiography for further evaluation of the aorta, the aortic arch vessels, and any other associated anomalies. Computed tomographic angiography revealed a left-sided aortic arch with a tight discrete juxtaductal coarctation (yellow arrow), with the narrowest segment measuring approximately 4.7 mm. Incidentally, a unique arrangement of the arch vessels was observed wherein the aberrant right subclavian artery (aRSCA) and the left subclavian artery (LSCA) were seen to arise from the coarctation segment (Figures 1A, 1B ). The right common carotid artery was also seen to have an early bifurcation within the thoracic inlet. Additional findings included a bicuspid aortic valve and prolapse of the anterior mitral valve leaflet. No other intracardiac defect was noted. The origin of both subclavian arteries from the coarctation segment is exceedingly rare. The posterior cerebral circulation may be at risk in the event of an inadvertent iatrogenic dissection, thus complicating therapeutic balloon dilatation of aortic coarctation, extending into the precariously placed subclavian arteries. The described anatomy also places the patient at a higher risk for paraplegia during surgical repair secondary to aortic cross-clamping proximal to the coarctation segment because supply to both spinal arteries will be hampered.