INNOMINATE-ARTERY STEAL SYNDROME AFTER STAGE-I PALLIATION FOR HYPOPLASTIC LEFT-HEART SYNDROME

Four neonates with hypoplastic left heart syndrome (HLHS) were found t o have innominate artery steal syndrome (LASS) following stage I palli ation with a modified Blalock-Taussig (B-T) shunt. All patients presen ted in the early postoperative period with a persistent supplemental o xygen requirement. Two-dimensional echocardiography with Doppler flow analysis and cardiac catheterization with angiography demonstrated obs truction at the origin of the innominate artery. This obstruction was associated with intermittent retrograde flow through the right vertebr al and common. carotid arteries into the distal innominate artery and modified B-T shunt. An ascending neoaorta to right pulmonary artery sh unt, with takedown of the B-T shunt, was performed in two of the patie nts. The other two patients were treated with percutaneous balloon dil atation of the obstructed area. Both procedures improved arterial bloo d oxygen saturations and eliminated the need for supplemental oxygen. In three of four patients, the left common carotid artery was found to be larger than the right. All four patients developed microcephaly, a nd one patient had encephalomalacia in the distribution of the right a nterior and middle cerebral arteries. The development of IASS followin g stage I palliation for HLHS and the association of neurologic sequel ae from this complication are discussed.