Neonatal and infantile Ebstein anomaly (EA) represents a rare and heterogeneous condition characterized by significant clinical instability in affected patients. Overall mortality is approximately 27%, with primary repair-related mortality reaching 40% and one-year survival at 37%. Neonates and infants exhibit worse outcomes, with mortality rates approaching 50%.
The Clinical Practice Standards Committee of the American Association for Thoracic Surgery (AATS)—comprising 12 pediatric cardiac surgeons and 2 pediatric cardiologists—reviewed over 400 articles on EA published since 2000. Among them, 71 focused on EA in neonates and infants. These articles, combined with the committee’s collective experience, formed the basis of the following recommendations:
- Prenatal Diagnosis
In cases of suspected severe EA, prenatal evaluation and monitoring should occur in a center with a multidisciplinary team including pediatric cardiac surgeons, pediatric cardiologists, and pediatric cardiac intensive care specialists. The team should be prepared to assess the high-risk neonate at delivery.
- Preoperative Assessment and Risk Stratification
“High-risk cases for intrauterine death and postnatal morbidity/mortality should be identified by fetal echocardiography findings of early cardiomegaly, bidirectional shunting at the ductus arteriosus, anatomic or functional pulmonary valve atresia, circular shunting, left ventricular (LV) dysfunction, low right ventricular systolic pressure (RVSP <20-25 mm Hg), or fetal hydrops (I-B).”
EA presents a wide spectrum of clinical manifestations. Depending on the severity and degree of delamination of the septal and posterior leaflets, presentations may range from silent to massive tricuspid regurgitation (TR). All fetuses with EA are at risk of developing fetal hydrops and heart failure, with intrauterine death occurring in approximately 20% of cases. One-third of live-born neonates with severe pathology die in the neonatal period. These neonates often exhibit severe cardiomegaly caused by significant volume overload due to severe TR, leading to marked dilation of the right atrium (RA) and atrialized right ventricle (RV), which may occupy the entire thoracic cavity. This expansion restricts pulmonary growth, often resulting in hypoplasia. Severe dilation of the right chambers compromises LV function due to impaired circumferential contractility and diastolic filling caused by ventricular-ventricular interaction. Consequently, cardiovascular compromise exacerbates low cardiac output, affecting cerebral oxygen delivery. Additionally, RA dilation is frequently associated with supraventricular arrhythmias, further destabilizing an already fragile circulation.
“Fetal echocardiographic evaluation should occur every 2-4 weeks until the 32nd week, after which it should increase to every 1-2 weeks, as high-risk features typically manifest later in gestation (I-B).”
Fetuses face risks of hydrops and maternal mirror syndrome (triple edema involving the fetus, placenta, and mother), with associated complications. Identifying risk factors enables coordination of delivery timing and the decision to administer corticosteroids to enhance fetal lung maturity.
“High-risk fetuses should be delivered in centers with expertise in ECMO and cardiac surgery (I-C).”
- Management of an Unstable Neonate
“Unstable neonates with a circular shunt require emergent intervention to interrupt the shunt (I-B).”
A circular shunt occurs when pulmonary regurgitation (PR) permits blood flow from the aorta to the pulmonary artery via the ductus arteriosus, which then passes through the RV and RA via severe TR. Blood is subsequently shunted to the left heart via an atrial communication and re-enters the aorta, perpetuating the cycle. This condition often develops within hours after birth, leading to cardiogenic shock.
“Neonates in refractory cardiogenic shock, despite inotropic support, mechanical ventilation, and prostaglandin therapy for ductal-dependent pulmonary blood flow, should undergo palliative Starnes procedure (I-C).”
The Starnes procedure creates a single-ventricle physiology by excluding the RV with a fenestrated patch, often combined with RA reduction. This approach improves LV contractility by reducing right-sided volumes. Alternative strategies include biventricular repair, such as the Knott-Craig technique, in cases without anatomic pulmonary atresia. While the Starnes procedure offers consistent outcomes, it does not preclude future biventricular repair.
“In neonates with hemodynamic instability, circular shunt, and low RVSP (<25 mm Hg), the main pulmonary artery should be ligated/occluded, and the Starnes procedure performed (I-C).”
When anatomic pulmonary atresia is present, immediate surgical intervention is warranted. Approximately 20% of patients develop postoperative heart block, which can be mitigated by securing the patch over Todaro’s ligament. The goal of intervention is RV decompression.
“Comfort measures may be considered for neonates with severe associated comorbidities, including prematurity, genetic syndromes, or significant medical complications.”
- Management of a Stable Neonate
“In neonates with functional pulmonary atresia and normal RVSP (>25 mm Hg), a medical trial of ductal closure should be performed. If the first attempt fails, additional attempts can be made within the first two weeks of life (I-C).”
In neonates with severe EA, normal RVSP may suffice to maintain adequate pulmonary blood flow once the ductus arteriosus closes. Prolonged ductal patency exposes the RV to systemic pressure, potentially impeding ejection. After ductal closure, pulmonary vasodilators may help reduce pulmonary resistance, facilitating RV ejection.
“Hemodynamically stable neonates with EA, normal RVSP (>25 mm Hg), and PR at risk of developing a circular shunt should undergo medical closure of the ductus arteriosus (I-C).”
In neonates with adequate RV pressure but insufficient antegrade pulmonary blood flow, interventions such as ductal stenting or a Blalock-Taussig (BT) shunt may be necessary as initial palliation before biventricular repair. In symptomatic neonates with stable hemodynamics but dependence on prostaglandins or respiratory support, these palliative strategies can stabilize the patient until definitive repair at 3-5 months of age.
- Subsequent Procedures Following Initial Palliation
“Following the Starnes procedure, subsequent interventions should progress toward either single-ventricle palliation or biventricular repair (I-C).”
Performing the Starnes procedure does not obligate a single-ventricle pathway. Echocardiographic evaluations every 2-4 weeks and magnetic resonance imaging (MRI) every 3-4 months are essential to determine RV viability for biventricular repair. The feasibility of such repair depends on the size and function of the RV assessed objectively.
Biventricular repair may involve removing the intraluminal pulmonary artery patch and reconstructing the tricuspid valve. If the RV is insufficiently developed, a 1.5-ventricle repair, combining a bidirectional cavopulmonary shunt (BCPS) with partial RV function, may be appropriate. Preservation of the pulmonary valve and careful placement of patches to avoid damaging the conduction system are critical technical considerations.
COMMENTARY:
The consensus document on managing EA in neonates and infants is an invaluable resource for practitioners caring for these patients. The committee has meticulously reviewed the literature to provide evidence-based recommendations for optimal clinical practice. The document delves into outcomes of various surgical techniques, with or without modifications, and I strongly recommend it to anyone involved in treating EA.
REFERENCE:
Konstantinov IE, Chai P, Bacha E, Caldarone CA, Da Silva JP, Da Fonseca Da Silva L, et al. The American Association for Thoracic Surgery (AATS) 2024 expert consensus document: Management of neonates and infants with Ebstein anomaly. J Thorac Cardiovasc Surg. 2024 Aug;168(2):311-324. doi: 10.1016/j.jtcvs.2024.04.018.
