Consequences of Right Ventricle–to–Pulmonary Artery Shunt at the First Stage for the Fontan Operation

Abstract

The evidence of the advantageous physiology associated with right ventricle-to-pulmonary artery (RV-PA) shunt in the early postoperative period after the Norwood procedure for hypoplastic left heart syndrome has been recently widely reported. We investigated the late consequences of this modification from the perspective of the third-stage palliation, the Fontan operation. Between September 1995 and November 2006, a consecutive series of 50 children with hypoplastic left heart syndrome from a single institution underwent a fenestrated Fontan operation (lateral tunnel technique): group 1 (n = 19) after the modified Blalock-Taussig shunt, and group 2 (n = 31) after RV-PA shunt during the Norwood procedure. Hemodynamic, echocardiographic, electrocardiographic, and clinical operative and perioperative data were analyzed. Children after the RV-PA shunt were characterized by higher preoperative partial oxygen tension in pulmonary arteries (p = 0.018) and the aorta (p = 0.028), as well as lower systolic, diastolic, and mean aortic pressure (p = 0.005, p = 0.004, p = 0.019). After administration of 100% oxygen, this group additionally showed a lower value for systemic resistance (p = 0.013). The analyzed angiograms revealed a higher incidence of systemic-to-pulmonary collateral vessels (p = 0.003) in group 2. At the discharge after Fontan operation, children after the RV-PA shunt demonstrated higher arterial partial oxygen tension (p = 0.004). The two groups did not differ significantly with respect to the mortality, ventricular function, incidence of pleural effusions or rhythm disturbances, intensive care unit stay, and hospitalization time. The Norwood procedure with the RV-PA shunt provides satisfactory late hemodynamics. Children who underwent this method of palliation were more prone to the development of systemic-to-pulmonary arterial collaterals.