Neonatal Ebstein repair—where are we now?
Ebstein anomaly is a cardiomyopathy characterized by arrested delamination of the tricuspid valve leaflets. This results in displacement of the hinge points of the leaflets into the right ventricle (RV) cavity. The right ventricular myocardium, and in 10–15% the left ventricular myocardium, will have varying degrees of abnormalities in structure and function. The wide anatomic spectrum of Ebstein anomaly results in a highly variable clinical presentation ranging from the severely symptomatic newborn to the asymptomatic adult. Most infants with Ebstein anomaly and mild or moderate cardiomegaly will be asymptomatic at birth. However, when severe cardiomegaly, severe tricuspid regurgitation, and additional cardiac lesions coexist, the neonate can present with profound cyanosis, severe heart failure, and shock. Further complicating the management of the symptomatic neonate are elevated pulmonary vascular resistance, compromised lung volumes due to severe cardiomegaly and reduced effective RV size and function. This combination of findings can result in functional pulmonary atresia if the RV is inadequate to provide antegrade pulmonary blood flow. Despite maximal medical therapy using prostaglandin infusion to maintain ductal patency, inhaled nitric oxide to lower pulmonary vascular resistance, and inotropic support, some patients will require surgical intervention in the neonatal period. Surgical outcomes for neonatal Ebstein repair continue to be challenging although recent reports are demonstrating improved survival. Neonatal surgical options include tricuspid valvuloplasty, reduction atrioplasty and subtotal closure of the atrial septal defect (biventricular repair), or single ventricle palliation ultimately resulting in a Fontan procedure.