Stage I palliation of hypoplastic left heart syndrome: The importance of neoaorta construction

Abstract

After Norwood's initial report of successful first-stage palliation of hypoplastic left heart syndrome in neonates, the occurrence of distal aortic obstructions, shunt problems, and late deaths have led to modifications in the surgical technique. Between January 1986 and December 1987, 12 neonates from three to 16 days old underwent stage I palliation with the same objectives. An open atrial septectomy was always performed. The pulmonary artery bifurcation was transected from the main pulmonary artery and closed with an aortic homograft patch. The aortotomy was begun 2 cm below the patent ductus arteriosus insertion and extended across the transverse arch and down the ascending aorta. The neoaorta was constructed using the hypoplastic ascending aorta-transverse aortic arch, the main pulmonary artery, and an aortic homograft augmentation patch. The homograft is hemostatic and pliable, and molds well in forming the neoaorta. A 4-mm shunt was inserted between the right innominate artery and the right pulmonary artery in 5 patients and the neoaorta and the pulmonary artery bifurcation patch in 7 patients. The early systemic oxygen saturation was optimized at 75% to 80% with hyperventilation, high concentration of inspired oxygen, sodium bicarbonate, and the frequent use of vasopressors to maintain an arterial blood pressure of 65 to 75 mm Hg. Two patients (17%) died early after operation; 1 had severe right ventricular dysfunction and both had severe tricuspid regurgitation. There were 2 late deaths at 7 and 13 months, of sepsis and hypoxia. The 8 survivors (67%) continue to do well over follow-up. The preoperative tricuspid regurgitation has remained stable in 3 survivors and disappeared in 2 survivors. Critical attention to construction of the neoaorta and careful ventilatory and pharmacological management of the ratio of pulmonary to systemic vascular resistance has led to unproved survival after stage I palliation.