Tetralogy of Fallot With Pulmonary Atresia Treatment & Management

Updated: Nov 22, 2015
  • Author: Michael D Pettersen, MD; Chief Editor: Howard S Weber, MD, FSCAI  more...
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Treatment

Approach Considerations

Admit patients with tetralogy of Fallot with pulmonary atresia (TOF-PA) for testing and potential surgical intervention. Transfer to a tertiary care center is indicated for complete diagnostic evaluation and surgical intervention.

Newborn infants with cyanosis due to congenital heart disease almost always benefit from administration of prostaglandin E1 (PGE1) to maintain ductal patency while a definitive diagnosis is made. Once the diagnosis of TOF-PA is made, the need for a PGE1 infusion is dependent on whether a ductus arteriosus is, in fact, present. If the only sources of pulmonary blood flow are major aortopulmonary collateral arteries (MAPCAs), then a PGE1 infusion is not necessary.

Older infants with increased pulmonary blood flow may require treatment for heart failure.

All patients with TOF-PA who have undergone either palliative surgical intervention (shunt procedure) or complete repair (conduit placement) are required to take appropriate prophylactic antibiotics to avoid bacterial endocarditis.

Findings from a retrospective study of 12 patients with TOF-PA and MAPCAs suggest that use of pulmonary hypertension medications may provide symptomatic improvement and are well tolerated. [14] It remains unknown whether these medications confer any long-term survival benefit in those with complex congenital heart disease. [14]

Nutritional support

Infants who are born with multiple systemic-to-pulmonary collaterals and are in cardiac failure because of pulmonary overcirculation require caloric supplementation to establish a normal growth pattern. Caloric intake as high as 130-150 kcal/kg/d may be required to ensure adequate growth.

Children that undergo palliative procedures also require optimization of their caloric intake. Adequate nutritional supplementation in the form of total parental nutrition must also be ascertained in the perioperative period. These patients often have a prolonged postoperative recovery course.

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Surgical Intervention

Neonates with adequate-sized confluent pulmonary arteries may be amenable to primary definitive surgical repair. A palliative procedure with a systemic–to–pulmonary artery shunt may be performed to promote central pulmonary artery growth prior to complete repair at a later date. The ultimate surgical goals are: (1) to incorporate as many pulmonary artery segments as possible into a pulmonary artery confluence, (2) to place a conduit from the right ventricle to the pulmonary artery confluence, and (3) to close the ventricular septal defect (VSD). While the primary intervention in the majority of patients is surgical, selected cases may be amenable to transcatheter perforation of the right ventricular outflow tract followed by balloon dilation. [23]

Hypoplastic pulmonary arteries

When the pulmonary arteries are hypoplastic, nonconfluent, and supplied by aortopulmonary collaterals, a multistaged repair is often required. [24] Hypoplastic pulmonary arteries generally require palliative shunting to induce enlargement and growth of these vessels so they can be successfully incorporated into the complete repair. The shunts used may be a modified Blalock-Taussig or central shunt and may be unilateral or bilateral. Another important strategy to maximize the long-term outcome in this group of patients is the early unifocalization of as many of the aortopulmonary collaterals as possible into a central pulmonary artery confluence. [25, 26, 27, 28] This maximizes the recruitment of lung segments, increasing the cross-sectional area of the pulmonary vascular bed, and it may increase the likelihood of performing a definitive repair.

Complete repair following palliation

For complete repair to be performed in a child who has undergone palliation: (1) The central pulmonary arterial area must be greater than 50% of normal; (2) predominantly left-to-right shunting at the ventricular level (VSD) must be present; (3) the equivalent of an entire lung must be supplied by the central pulmonary artery confluence; and (4) stenotic lesions in the pulmonary artery outflow must be addressed.

The choice of the optimal type of conduit for a growing child remains controversial. Current options include cryopreserved aortic or pulmonary homografts, glutaraldehyde fixed bovine jugular vein grafts, and synthetic conduits, with variable intermediate-term results reported in the medical literature. [29, 30, 31] Patients with membranous pulmonary atresia may be amenable to repair using a pulmonary transannular patch. These patients have an improved freedom from reintervention compared with patients who receive right ventricle-to-pulmonary artery conduits. [32]

Significant pulmonic valve regurgitation often occurs regardless of the type of conduit placed between the right ventricle and the pulmonary arteries. Some patients develop substantial right ventricular dilation and right ventricular dysfunction. Surgical placement of a pulmonic valve may significantly benefit these patients. More recently, a transcatheter-placed pulmonary valve comprising a valved segment of bovine jugular vein sewn within a balloon-expandable stent has been made commercially available. This valve can be placed in patients with postoperative conduit dysfunction consisting of pulmonary regurgitation, obstruction, or both. However, the existing conduit has to be approximately 16 mm in diameter at the time of its original implantation. Early and midterm results with this valve suggest a high rate of procedural success and encouraging valve function. [33]

Single-stage repair

Some centers have shifted toward performing a single-stage repair, wherein all the multiple aortopulmonary collaterals (MAPCAs) are ligated at the aorta. [34, 35] These MAPCAs are then mobilized toward the posterior mediastinum to construct a pulmonary artery confluence, followed by insertion of a pulmonary allograft to establish continuity between these neopulmonary arteries and the right ventricle. The ventricular septal defect (VSD) is closed.

These centers have reported good results. Infants with postunifocalization pulmonary arteries that, combined, are only mildly hypoplastic (> 200 mm2/m2) have a lower mortality rate and acceptable right ventricular pressures. However, many patients require repeat catheterizations for balloon dilation or stent placements in stenotic pulmonary artery segments to alleviate elevated right ventricular pressures. [36]

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Consultations

The following consultations are advised:

  • Pediatric cardiology consultation

  • Geneticist consultation to evaluate the presence of syndromic associations and gene deletions, especially in the presence of associated anomalies or dysmorphic features

  • Cardiovascular surgical consultation, once the anatomy of a child with tetralogy of Fallot with pulmonary atresia (TOF-PA) is determined by echocardiography and angiography findings (see Workup);the caregivers need to be aware of the possibility of a multistage repair and repeated surgeries and catheterizations

  • Consultations and follow-up with the appropriate specialists for anomalies involving other systems

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Long-Term Monitoring

Infants with multiple aortopulmonary collaterals may require outpatient medical management of heart failure.

Residual right ventricular hypertension with right ventricular dysfunction from hypoplastic pulmonary arteries may be present.

After each stage of surgical reconstruction, echocardiographic evaluation of hemodynamic adequacy should be performed. After complete repair and during clinical follow-up, the patient needs to be evaluated for the development of right ventricle–to–pulmonary artery conduit stenosis as well as pulmonary valve regurgitation.

Some patients may never reach the stage of complete repair because of very hypoplastic and discontinuous pulmonary arteries. These patients are often hypoxemic and polycythemic, requiring oxygen supplementation. Patients who are chronically cyanotic should be carefully monitored for complications related to polycythemia and iron deficiency anemia.

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