What is the best course of treatment for a patient with Tricuspid Valve Atresia, hypoplastic right ventricle, and severe Pulmonic Stenosis?

Management of Tricuspid Atresia with Hypoplastic Right Ventricle and Severe Pulmonic Stenosis

This patient requires urgent staged surgical palliation beginning with prostaglandin E1 (PGE1) infusion to maintain ductal patency, followed by a systemic-to-pulmonary artery shunt as the first-stage procedure, with eventual progression toward Fontan completion as the definitive treatment.

Immediate Medical Management

• Initiate PGE1 infusion immediately to maintain patency of the 0.2cm patent ductus arteriosus, which is the only source of pulmonary blood flow given the severe pulmonic stenosis with minimal forward flow 1
• The PGE1 infusion has been shown to significantly improve clinical prognosis in patients with pulmonary atresia/critical stenosis and intact ventricular septum 1
• Aggressive diuretic therapy is not indicated at this stage, as the patient has good left ventricular systolic function (EF 66%) and the priority is maintaining adequate pulmonary blood flow, not managing volume overload 2

Surgical Strategy: Staged Palliation Approach

First Stage: Establishing Reliable Pulmonary Blood Flow

• Perform a systemic-to-pulmonary artery shunt (modified Blalock-Taussig shunt or central shunt) as the initial palliative procedure 3, 1
• Pulmonary valvotomy alone is inadequate given the severe stenosis (0.3cm annulus) and minimal forward flow; a shunt procedure is necessary 1
• The small pulmonary arteries (0.3cm) make this technically challenging but feasible, as the goal is to promote pulmonary artery growth for subsequent stages 3

Critical Anatomic Considerations

• The hypoplastic right ventricle with tricuspid atresia makes biventricular repair impossible 3, 4
• Right ventricular decompression through tricuspid valve manipulation is not applicable here since the tricuspid valve is atretic 4
• The good left ventricular function (EF 66%) is favorable for single-ventricle palliation 3

Second Stage: Bidirectional Glenn or Hemi-Fontan

• Once the patient is 4-6 months old with adequate pulmonary artery growth, perform a bidirectional cavopulmonary anastomosis (Glenn procedure) 1
• This directs superior vena caval blood to the pulmonary arteries, reducing volume load on the single left ventricle 3, 1
• The right atrium becomes "ventriculized" to handle the hemodynamic changes 3

Third Stage: Fontan Completion

• At 2-4 years of age, complete the Fontan procedure to direct inferior vena caval blood to the pulmonary circulation 3, 5
• This establishes total cavopulmonary connection, separating systemic and pulmonary circulations entirely 3
• Success depends on adequate pulmonary artery size and low pulmonary vascular resistance, which must be assessed before proceeding 3, 1

Alternative Interventional Approach (Limited Role)

• Percutaneous transluminal pulmonary valvuloplasty could theoretically be attempted via a femoral artery approach through the aorta, left ventricle, and VSD to reach the pulmonary valve 6
• However, this is not recommended as primary therapy given the severe hypoplasia (0.3cm annulus) and minimal forward flow, which indicate the valve is not amenable to simple balloon dilation 6, 1
• Catheter intervention may have a role in select cases to augment pulmonary blood flow but cannot replace staged surgical palliation in this anatomy 6

Critical Pitfalls to Avoid

• Do not delay PGE1 initiation while awaiting surgical consultation; ductal closure will result in profound hypoxemia and death given the severe pulmonic stenosis 1
• Do not attempt biventricular repair despite the presence of a ventricular septal defect; the hypoplastic right ventricle and atretic tricuspid valve preclude this approach 3, 4
• Do not proceed to Fontan completion prematurely without adequate pulmonary artery growth and assessment of pulmonary vascular resistance; the currently small (0.3cm) pulmonary arteries require growth through staged palliation 3, 1
• Avoid isolated pulmonary valvotomy as the sole first-stage procedure; it will be inadequate given the severity of stenosis and hypoplasia 1

Prognostic Factors

• The preserved left ventricular function (EF 66%) is highly favorable for successful single-ventricle palliation 3
• The small pulmonary arteries (0.3cm) represent a significant challenge but can grow with adequate shunt flow 3, 1
• Right atrial enlargement is expected in this anatomy and will be addressed through the staged palliation sequence 3
• Successful cases have been reported with this approach, though the overall prognosis depends on pulmonary artery development and absence of significant atrioventricular valve regurgitation 5