Abstract
Right-to-left shunt due to abnormal systemic venous drainage to the left heart is among the causes of hypoxemia following Fontan operation. There are conflicting data regarding the closure of the venovenous collaterals (VVCs) post-Fontan, showing decreased survival in older patients. In a child with visceral heterotaxy, we describe a rare fistula draining a right-sided hepatic vein into hepatic venous plexus and a right-sided pulmonary venous atrium. The patient presented with severe hypoxemia post-Fontan and underwent fistula occlusion with AMPLATZER™ Vascular Plug II, successfully improving hemodynamic status with resolution of the hypoxemia. Younger patients with cyanosis due to VVCs may benefit from percutaneous occlusion post-Fontan.