What is the recommended management for a newborn with critical aortic stenosis?

Management of Neonatal Critical Aortic Stenosis

Aortic balloon valvuloplasty is the first-line intervention for newborns with critical aortic stenosis who are ductal-dependent or have depressed left ventricular systolic function, regardless of the valve gradient. 1

Initial Stabilization

Prostaglandin E1 Infusion

• Immediately initiate prostaglandin E1 (alprostadil) infusion to maintain ductal patency and preserve systemic perfusion 2, 3
• Alprostadil reopens or maintains patency of the ductus arteriosus, which is critical for systemic blood flow in ductal-dependent critical aortic stenosis 2
• The drug is metabolized rapidly (80% in one pass through the lungs), requiring continuous infusion 2

Hemodynamic Support

• Provide inotropic support to optimize myocardial oxygen delivery and reduce metabolic consumption 3
• Mechanical ventilation may be necessary to reduce myocardial work and oxygen demand 3
• Maintain adequate hydration to prevent complications from increased blood viscosity 4

Diagnostic Evaluation

• Perform comprehensive echocardiography to confirm the diagnosis, assess valve morphology, left ventricular size and function, and evaluate for endocardial fibroelastosis 5, 3
• Measure the aortic annular size, as this predicts the need for future reintervention 6
• Assess for secondary pulmonary hypertension, which develops due to left ventricular diastolic dysfunction 5

Definitive Intervention

Balloon Aortic Valvuloplasty (First-Line)

The American Heart Association provides Class I indication for aortic valvuloplasty in newborns with critical aortic stenosis who are ductal-dependent, regardless of gradient. 1

Technical Considerations

• The optimal balloon-to-annulus diameter ratio is 0.9 to 1.0 1
• Ratios <0.9 are associated with suboptimal outcomes and higher residual gradients 1
• Ratios >1.0 significantly increase the risk of severe aortic regurgitation 1
• A technically adequate dilation typically reduces the peak-to-peak systolic gradient to 20-35 mm Hg 1

Expected Outcomes

• The VACA Registry demonstrated 60% reduction in peak systolic gradient across 606 pediatric patients 1
• Risk factors for suboptimal outcomes include age <3 months, higher pre-dilation gradients, and presence of unrepaired coarctation 1
• Reintervention-free survival is 48% at 5 years in neonates, underscoring the palliative nature of this procedure 1

Surgical Valvotomy (Alternative)

• Open aortic valvotomy under direct vision allows precise splitting of fused commissures and removal of obstructing nodules 7
• Some centers report superior results with surgical valvotomy, particularly for tricuspid valve morphology, with actuarial survival of 92% at 1 month and 73% at 10 years 6, 7
• Early mortality is concentrated in neonates <2 weeks of age (11% overall early mortality) 6
• Freedom from reintervention is 73% at 1 year and 55% at 10 years after surgical valvotomy 6

Critical Decision Points

Biventricular vs. Univentricular Pathway

The presence of adequate left ventricular size and absence of severe endocardial fibroelastosis favor biventricular repair. 6, 8

• Small left ventricle, severe endocardial fibroelastosis, and small body surface area predict mortality and poor outcomes with biventricular repair 6
• Patients with very small left ventricles may require univentricular Norwood palliation 8
• In infants with aortic annular hypoplasia but adequately sized left ventricle, the Ross-Konno procedure is an option 8

Multidisciplinary Team Approach

• Management requires coordination between pediatric cardiothoracic surgeons, interventional cardiologists, cardiac intensivists, and transplant specialists 3
• Cardiac catheterization expertise is essential for both diagnostic evaluation and therapeutic intervention 3

Post-Intervention Management

Immediate Post-Procedure

• The left ventricle remodels and grows toward normal values by one year after successful intervention 5
• Pulmonary hypertension may persist during childhood despite successful relief of obstruction 5
• Monitor for development of aortic regurgitation, which occurs uncommonly but can be severe 1

Long-Term Follow-Up

• Serial echocardiography is mandatory to monitor for restenosis and progressive aortic regurgitation 5
• Reintervention is eventually required in the majority of patients due to late restenosis or valve regurgitation 1
• At long-term follow-up, survivors without reintervention typically have peak gradients of 37±14 mm Hg and mild or less aortic regurgitation 6

Common Pitfalls

• Avoid undersized balloons during valvuloplasty, as this leads to inadequate relief and procedure failure 9
• Avoid oversized balloons (>1.0 balloon-to-annulus ratio), which significantly increase the risk of severe aortic regurgitation 1
• Do not delay intervention in ductal-dependent neonates, as elevated left ventricular wall stress disrupts coronary perfusion and leads to irreversible myocardial dysfunction 3
• Recognize that this is a palliative procedure, not a cure—families should understand that most patients will require future reinterventions 1