What is the management approach for a fetus diagnosed with common arterial trunk and Tetralogy of Fallot (TOF) with pulmonary atresia?

Management of Fetus Diagnosed with Common Arterial Trunk and Tetralogy of Fallot with Pulmonary Atresia

Fetuses diagnosed with common arterial trunk and Tetralogy of Fallot (TOF) with pulmonary atresia should be referred to a specialized fetal care center for comprehensive evaluation, management planning, and delivery coordination to optimize outcomes.

Prenatal Diagnosis and Assessment

• Accurate prenatal diagnosis requires expert fetal echocardiography with multiplanar imaging to distinguish between truncus arteriosus and TOF with pulmonary atresia, as they share sonographic findings of a single arterial trunk overriding a ventricular septal defect (VSD) 1
• Key diagnostic features for TOF with pulmonary atresia include: large aortic root, absence of pulmonary artery or right ventricular outflow tract, VSD in the outlet portion of the septum, overriding aorta (best seen in long-axis view), and right ventricular hypertrophy 2
• Careful examination along the course of the ascending aorta is essential to differentiate TOF with pulmonary atresia from truncus arteriosus, as in TOF there are no pulmonary branches arising directly from the aorta 2
• Assessment of pulmonary blood flow sources is critical - patients may have confluent branch pulmonary arteries fed by ductus arteriosus or major aortopulmonary collateral arteries (MAPCAs) 3

Prenatal Management

• Screening for 22q11.2 deletion syndrome should be offered to all pregnant women with fetuses diagnosed with conotruncal abnormalities like TOF and truncus arteriosus 4, 5
• Genetic consultation should be arranged if 22q11.2 deletion or other genetic syndrome is identified to provide appropriate counseling 4
• Regular fetal echocardiographic monitoring should be performed by specialists with expertise in congenital heart disease to assess progression and plan for delivery 4
• Fetal echocardiography should be performed at least every 2-4 weeks to monitor cardiac function and development 4

Delivery Planning

• Delivery should be planned at a tertiary care center with expertise in neonatal cardiac care and immediate access to pediatric cardiac surgery 4
• A multidisciplinary team including maternal-fetal medicine specialists, pediatric cardiologists, cardiac surgeons, and neonatologists should coordinate care 4
• Cesarean delivery is not routinely indicated based solely on the cardiac diagnosis and should follow standard obstetric indications 4

Postnatal Management

• Immediate postnatal assessment should include evaluation of oxygenation status, cardiac function, and confirmation of diagnosis 6
• For TOF with pulmonary atresia, management is determined by:
  • Pulmonary artery anatomy (confluent vs. non-confluent)
  • Source of pulmonary blood flow (duct-dependent vs. MAPCAs)
  • Presence of associated anomalies 4, 3

Surgical Approach

• Surgical management should be individualized based on anatomy, pulmonary blood flow, and clinical status 7, 3
• Options include:
  1. For infants with favorable anatomy: Complete repair may be performed between 3-6 months of age 7
  2. For symptomatic neonates <4kg: Initial palliation with modified Blalock-Taussig shunt followed by complete repair at 6-12 months 7
  3. For complex pulmonary anatomy: Staged approach with initial palliation followed by unifocalization of pulmonary blood supply and eventual complete repair 4, 3

Long-term Considerations

• Patients with TOF with pulmonary atresia have higher risk for reinterventions to address pulmonary arterial or RV-pulmonary artery conduit stenosis, progressive aortic root dilation, and aortic insufficiency compared to less severe forms of TOF 3
• Long-term follow-up should include regular assessment for arrhythmias, right ventricular function, and need for reintervention 4, 3
• Patients should have at least annual follow-up with a cardiologist who has expertise in adult congenital heart disease 4

Parental Counseling

• Parents should be counseled about:
  • The complexity of the cardiac defect and need for multiple surgeries
  • Potential association with genetic syndromes (particularly 22q11.2 deletion)
  • Long-term outcomes and quality of life expectations
  • Risk of recurrence in future pregnancies (4-6% without 22q11 deletion, 50% with 22q11 deletion) 4
• Fetal echocardiography should be offered in future pregnancies 4