What is the recommended treatment for an infant or young child with Tetralogy of Fallot (TOF) and absent pulmonary valve?

Tetralogy of Fallot with Absent Pulmonary Valve: Treatment Recommendations

Definitive Surgical Management

Complete surgical repair should be performed in infancy (typically 3-6 months of age) and must include pulmonary valve insertion at the time of intracardiac repair, as patients without valve insertion remain symptomatic and frequently require subsequent reoperation. 1

The surgical approach for TOF with absent pulmonary valve differs critically from standard TOF repair due to the unique pathophysiology of massive pulmonary artery dilatation causing life-threatening bronchial compression. 2, 3

Surgical Technique Components

The complete repair must address five key anatomic elements simultaneously:

• VSD closure using a patch 4, 5
• Relief of RVOT obstruction 4, 6
• Pulmonary valve insertion using an aortic or pulmonary homograft (size 8-24 mm) or valved conduit, which is essential to prevent ongoing pulmonary regurgitation and symptom persistence 1, 5
• Pulmonary artery plication (anterior and/or posterior) to reduce aneurysmal dilatation and relieve bronchial compression 2, 5, 3
• Pulmonary artery translocation anterior to the aorta to move the vessel away from the airways, particularly critical in symptomatic infants 2

Critical Distinction from Standard TOF Repair

Unlike standard TOF repair where transannular patch without valve insertion is acceptable, TOF with absent pulmonary valve requires mandatory pulmonary valve insertion at the time of primary repair. Clinical evidence demonstrates that 5 of 6 patients who underwent repair without valve insertion remained symptomatic postoperatively, and 3 required subsequent valve insertion operations. 1 In contrast, all patients who received primary valve insertion were symptom-free following operation. 1

Age-Specific Considerations

Symptomatic Infants (Group at Highest Risk)

• Present with severe cardiorespiratory distress from bronchial compression 1, 7
• Require early aggressive medical intervention followed by urgent surgical repair 7
• May need preoperative ventilatory support or ECMO (used in 3 of 28 patients in one series) 3
• Have significantly higher mortality risk: all early deaths occurred in infants requiring preoperative intubation 3
• Preoperative intubation is the only multivariable predictor of worse outcome (p=0.04) 3

Elective Repair in Older Children

• Can be treated electively with excellent results 5
• Hospital mortality approaches 0% when not requiring preoperative ventilatory support 1, 5

Expected Outcomes

Contemporary surgical results demonstrate:

• Hospital mortality of 0-25% depending on age and preoperative respiratory status 5, 3
• Survival of 77% at 1 year and 72% at 10 years 3
• Freedom from death or reoperation of 68% at 1 year and 52% at 10 years 3
• Zero mortality in older children operated electively 5

Postoperative Surveillance

All patients require lifelong annual follow-up with an adult congenital heart disease specialist, including:

• History and physical examination 6
• 12-lead ECG 6
• Comprehensive echocardiography 6
• Cardiac MRI for RV volume quantification and pulmonary regurgitation assessment 6
• Periodic Holter monitoring 6

Reintervention Indications

Reoperation may be necessary for:

• Persistent respiratory symptoms from inadequate initial plication, requiring repeat plication and valved conduit placement 3
• Progressive RV enlargement or dysfunction 6
• Residual RVOT obstruction with RV/LV pressure ratio >0.7 6

Critical Pitfalls to Avoid

The most common error is performing standard TOF repair without pulmonary valve insertion. This approach, while acceptable for standard TOF, leads to persistent symptoms and need for reoperation in TOF with absent pulmonary valve. 1 The severity of pulmonary regurgitation is often underestimated by clinical examination alone, requiring serial CMR imaging for accurate assessment. 4

Inadequate pulmonary artery plication at the initial operation results in persistent bronchial compression and respiratory symptoms requiring reoperation. 3 Both anterior and posterior plication should be performed when significant dilatation is present. 5, 3

Delayed surgical intervention in symptomatic infants dramatically increases mortality risk, as all early deaths occurred in this group. 3 Early recognition and aggressive intervention are essential. 7