What is the recommended management for a neonate with a ventricular septal defect complicated by pulmonary arterial hypertension?

Management of Ventricular Septal Defect with Pulmonary Arterial Hypertension in Neonates

Neonates with VSD and PAH require urgent surgical repair before 2 years of age—ideally within the first months of life—to prevent irreversible pulmonary vascular disease, with immediate medical stabilization including oxygen therapy, diuretics, and consideration of pulmonary vasodilators for symptomatic PAH. 1

Immediate Stabilization and Diagnostic Evaluation

Oxygen and Respiratory Management

• Initiate supplemental oxygen immediately to maintain SpO2 ≥92-95% to reduce pulmonary vascular resistance and prevent right heart strain 2, 3
• For neonates with saturations >95% on room air and exclusive left-to-right shunting by echocardiography, cardiac catheterization may not be necessary before surgery if the infant is <1 year old 1
• Optimize lung recruitment while minimizing peak inspiratory pressures and avoiding large tidal volumes if mechanical ventilation is required 1, 2

Urgent Diagnostic Workup

• Perform comprehensive echocardiography urgently to assess VSD size, location, shunt direction, right ventricular hypertrophy, and estimate pulmonary artery pressure 2, 4
• Obtain ECG to evaluate for cor pulmonale (right axis deviation, right atrial enlargement, right ventricular hypertrophy) 2
• Cardiac catheterization is indicated for neonates presenting after several months of age or those with bidirectional shunting to measure pulmonary vascular resistance index (PVRI) and determine operability 1

Medical Management Prior to Surgery

Heart Failure Treatment

• Initiate diuretic therapy with furosemide or combination therapy with chlorothiazide and spironolactone to reduce pulmonary congestion 2
• Consider ACE inhibitor for afterload reduction if no contraindications 4

Pulmonary Vasodilator Therapy

• Inhaled nitric oxide (iNO) at 10-20 ppm initially, weaning to 2-10 ppm for maintenance, is recommended for symptomatic pulmonary hypertension 2, 3
• Sildenafil 0.5-2 mg/kg three times daily can be used as an alternative or adjunct to iNO, particularly when iNO is not available 3
• Pretreatment with sildenafil for 3 months before catheterization has been associated with improved outcomes in some series 5
• Treprostinil administered intravenously during the perioperative period significantly reduces postoperative pulmonary artery pressure and shortens mechanical ventilation time, ICU stay, and hospital stay 6

Surgical Timing and Operability Criteria

Age-Based Recommendations

• Surgery should be performed before 2 years of age, with most centers performing complete repair within the first months of life 1
• Children repaired before 9 months of age, regardless of preoperative Heath-Edwards scores or hemodynamic parameters, had normal pulmonary artery pressure 1 year after surgery 1
• No child repaired before 2 years of age had an elevated PVR-to-SVR ratio 4-8 years after surgery, regardless of initial PVR-to-SVR ratio 1

Hemodynamic Criteria for Operability

The following thresholds guide surgical decision-making based on cardiac catheterization:

• PVRI <6 WU·m² or PVR/SVR <0.3 at baseline: Surgery is recommended 1, 4
• PVRI 6-8 WU·m²: Acute vasodilator testing (AVT) with iNO should be performed 1
  • If AVT shows decrease in PVR and PVR/SVR >10% with absolute PVR/SVR <0.3, surgery can proceed 1
  • If minimal AVT responsiveness, consider PAH-targeted therapy for 4-6 months followed by repeat catheterization 4
• PVRI >8 WU·m²: Surgery is generally contraindicated unless significant vasoreactivity is demonstrated 1

Important caveat: Children with PVR >6 U·m² have a poor prognosis regardless of lung morphology, and some patients with low Heath-Edwards scores (grade I or II) can still have high PVR 1

Surgical Technique Considerations

Standard Approach

• Surgical approach is typically through the right atrium with patch closure of the VSD 7
• Elective postoperative ventilation for 36 hours with intravenous vasodilators (glyceryl trinitrate + phentolamine) and oral sildenafil up to 1 mg/kg every 6 hours 7

Modified Technique for High-Risk Patients

• For neonates with elevated PVR, consider leaving a patent foramen ovale (PFO) or creating a small (5mm) atrial septal defect to serve as a "pop-off" valve during pulmonary hypertensive crises 7
• The "double patch" technique (creating an intentional atrial communication) has shown favorable outcomes with hospital mortality of 2.5% compared to 10.1% with traditional patch closure in high-risk patients 5
• Long-term survival with the double patch technique exceeds 97%, with 61% of children having normal to mild elevations in pulmonary artery pressure at last follow-up 5

Management of Pulmonary Hypertensive Crisis

If acute pulmonary hypertensive crisis occurs postoperatively:

• Prostacyclin nebulization is effective for rescue therapy 7
• Maintain adequate sedation and analgesia
• Optimize ventilation to avoid hypoxia, hypercarbia, and acidosis
• Consider ECMO for patients with severe PAH who do not respond to medical therapy 1

Long-Term Follow-Up

Monitoring Schedule

• Serial echocardiograms initially every 2-4 weeks if pulmonary hypertension therapy is initiated 2
• Once stable, echocardiograms at 4-6 month intervals 2, 3
• Annual echocardiography for long-term surveillance 1

Weaning Oxygen and Medications

• Wean oxygen based on documented adequate saturations (≥92-95%) across all activity states, including awake, feeding, and sleeping periods 2, 3
• Perform overnight oximetry or polysomnography when considering weaning to ensure adequate nocturnal oxygenation 3
• PAH-targeted therapy should only be discontinued after confirming resolution of pulmonary hypertension on serial echocardiograms 3

Critical Pitfalls to Avoid

• Do not delay surgery beyond 2 years of age: Approximately 50% of patients with large VSD develop pulmonary vascular disease, and biologic variability means some children develop irreversible PVD in the first year of life 1
• Do not rely solely on oxygen response for operability: A positive preoperative response to oxygen (decrease in PVR-to-SVR ratio ≥30%) does not correlate with operative survival or late PVR-to-SVR ratio 1
• Do not use estimated VO2: The LaFarge equation overestimates VO2 in ventilated patients with CHD, particularly in children <3 years of age, leading to underestimation of PVR 1
• Do not assume normal PVR after repair: Despite surgical correction in infancy, some patients develop progressive pulmonary vascular disease postoperatively for unclear reasons 1