What are the guidelines for managing pulmonary atresia?

Management Guidelines for Pulmonary Atresia

Pulmonary atresia should be managed in specialized Adult Congenital Heart Disease (ACHD) centers with a multidisciplinary team approach, with treatment strategies determined by the specific anatomical subtype and pulmonary artery development pattern. 1

Classification and Types

Pulmonary atresia is classified as a "Great Complexity" (Class III) congenital heart defect according to the ACHD Anatomic and Physiological Classification system 1. There are two main types:

1. Pulmonary Atresia with Ventricular Septal Defect (PA+VSD)

   • Shares intracardiac anatomy with tetralogy of Fallot but lacks direct RV-PA communication
   • Three patterns of pulmonary arteries:
     • Unifocal with confluent good-sized PAs supplied by PDA
     • Multifocal with confluent but hypoplastic PAs supplied by MAPCAs
     • Multifocal with non-confluent PAs supplied by MAPCAs

2. Pulmonary Atresia with Intact Ventricular Septum (PA+IVS)

   • Associated with varying degrees of RV hypoplasia and tricuspid valve hypoplasia
   • May have RV-dependent coronary circulation

Diagnostic Evaluation

• Echocardiography: First-line diagnostic tool to assess anatomy and function
• Cardiac MRI/CT: Required to define pulmonary artery anatomy, collateral vessels, and ventricular function
• Cardiac catheterization: Essential to assess pulmonary vascular bed, hemodynamics, and coronary circulation (especially in PA+IVS)
• Genetic testing: Consider for microdeletion 22q11.2, which is common in PA+VSD 1

Management Algorithm for PA+VSD

Initial Management Based on PA Anatomy:

1. Confluent, good-sized PAs with pulmonary trunk:

   • Fallot-like repair using trans-annular patch

2. Confluent, good-sized PAs without pulmonary trunk:

   • Repair with RV-PA conduit

3. Confluent but hypoplastic PAs:

   • Initial arterial shunt or RVOT reconstruction (without VSD closure)
   • Later repair using valved conduit after PA growth

4. Non-confluent PAs:

   • Consider staged unifocalization approach 1, 2
   • For adequate pulmonary blood flow, may defer surgery

Management Algorithm for PA+IVS

Based on RV size and morphology 3:

1. Group A (Good-sized RV with membranous atresia):

   • Radiofrequency valvotomy as primary procedure
   • Often the only procedure required

2. Group B (Borderline RV size):

   • Radiofrequency valvotomy and PDA stenting ± balloon atrial septostomy
   • May require later interventions:
     • Bidirectional Glenn shunt (1½-ventricle repair) if RV fails to grow
     • RVOT reconstruction for subvalvar obstruction

3. Group C (Severely hypoplastic RV):

   • Single ventricle pathway:
     • PDA stenting with balloon atrial septostomy or BT shunt
     • Bidirectional Glenn shunt at 6-12 months
     • Fontan completion later

Follow-up Recommendations

• All patients require lifelong follow-up at specialized ACHD centers

• Regular assessment for:

  • Arrhythmias (common and potentially life-threatening)
  • Heart failure (leading cause of death)
  • Progressive cyanosis
  • Hemoptysis
  • Endocarditis
  • Aortic dilation and regurgitation

• Imaging surveillance:

  • Echocardiography at each visit
  • CMR/CT at regular intervals based on pathology

Special Considerations

Pregnancy

• High risk in unrepaired patients with significant maternal and fetal mortality
• Risk in repaired patients depends on hemodynamic status
• Patients with significant residual lesions have risk of arrhythmia and right heart failure 1

Exercise/Sports

• Asymptomatic patients with good hemodynamics: No restrictions
• High-risk patients (arrhythmias, ventricular dysfunction, aortopathy): Limit to low-intensity activity and avoid isometric exercise 1

Endocarditis Prophylaxis

• Recommended only for high-risk patients 1

Prognosis

Adult survivors with pulmonary atresia have high morbidity and mortality regardless of underlying cardiac anatomy or previous surgical interventions 4. Strongest predictors of mortality include:

• Systemic ventricular dysfunction
• Low resting oxygen saturations

Key Pitfalls to Avoid

1. Delayed recognition of deterioration: Regular follow-up is essential as clinical deterioration may be gradual
2. Inadequate imaging: Complete assessment of pulmonary vasculature is critical for management decisions
3. Failure to recognize RV-dependent coronary circulation in PA+IVS before intervention
4. Underestimating arrhythmia risk: Sudden cardiac death is a significant cause of mortality
5. Managing outside specialized centers: These complex patients require expertise in ACHD care

The complexity of pulmonary atresia necessitates individualized care at specialized centers with expertise in adult congenital heart disease to optimize outcomes and reduce mortality.