Truncus Arteriosus Treatment & Management

Updated: Dec 31, 2019
  • Author: Doff B McElhinney, MD; Chief Editor: Howard S Weber, MD, FSCAI  more...
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Treatment

Medical Care

Medical care before surgical repair depends on the neonate's clinical presentation.

Most neonates with truncus arteriosus display evidence of congestive heart failure and are usually treated with digitalis and diuretic medicines.

Intravenous prostaglandin is often administered in patients with truncus arteriosus upon presentation because the differential diagnosis includes numerous anomalies with duct-dependent systemic or pulmonary blood flow. However, it is beneficial only in patients with associated interruption of the aortic arch or aortic coarctation.

Other preoperative medications are not generally indicated, although specific circumstances may dictate afterload reducing agents, inotropic medications, or antiarrhythmics.

Full-term and premature newborns with truncus arteriosus may be at increased risk for necrotizing enterocolitis, either preoperatively or postoperatively, and appropriate evaluation should be undertaken in any newborn exhibiting signs or symptoms of necrotizing enterocolitis.

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Surgical Care

Indications

Truncus arteriosus invariably requires operative repair. [12] Symptoms typically develop in the early neonatal period, indicating that complete repair is required at this point.

Techniques

Surgical management of truncus arteriosus has undergone significant evolution over the past 30 years. Complete repair was first performed in 1967, but until neonatal and early infant repair became routine in the 1980s, palliative pulmonary artery banding was common, with complete repair performed at an older age. At most centers, primary complete repair in the neonate and young infant has become the accepted standard.

Currently, surgical management consists of complete primary repair, with closure of the ventricular septal defect, committing the common arterial trunk to the left ventricle, and reconstruction of the right ventricular outflow tract.

In patients with both branch pulmonary arteries arising from the common trunk, the standard method of right ventricular outflow tract reconstruction entails removing the central pulmonary arteries from the common trunk en bloc and placing a valved conduit from the right ventricle proximally to the central pulmonary arteries distally. Also, the most common type of conduit used is a cryopreserved valved aortic or pulmonary allograft. Before allograft conduits became widely available, other forms of pulmonary outflow reconstruction were used. These alternative forms remain in use in areas where the cost and availability of conduits prohibit routine use of modern techniques. Such alternatives include xenograft valves housed in synthetic tube grafts, direct anastomosis of the pulmonary arteries to the right ventriculotomy, or autologous flaps of pulmonary or aortic tissue augmented with synthetic patch material.

In patients with one pulmonary artery arising from the common trunk and one from the underside of the aortic arch, the pulmonary arteries are disconnected separately; they are then anastomosed together before being anastomosed to the conduit or are anastomosed to the conduit independently.

Coexisting anomalies are repaired as appropriate with cardiopulmonary bypass, cardioplegia, and sometimes deep hypothermic arrest, depending on anatomic features and the preference of the surgeon.

When the truncal valve is abnormal and repaired at the time of the initial truncus repair, outcomes appear to be significantly worse that when early truncal valve repair is not necessary. [13, 14]

Postoperative Care

Administer routine postoperative care, initially in the cardiac intensive care unit, following correction of truncus arteriosus. Support patients with mechanical ventilation, inotropic medications, and sedation as necessary. Restore fluid balance with diuretic therapy and continue tube thoracostomy until pleural and pericardial effusions have resolved.

Focus the remainder of the inpatient stay on providing sufficient enteral nutrition, parental education, and elucidation of the maintenance pharmacologic regimen (if any) that is adopted.

Postoperative care after repair of truncus arteriosus requires attention to issues that are common to patients with complex congenital heart disease (eg, support of cardiac output) and prevention or management of arrhythmias and end-organ dysfunction.

Management issues include maintenance of intravascular volume and ventricular filling, inotropic support, and acid-base and electrolyte homeostasis. In addition, potential issues that are of particular concern in patients with truncus arteriosus include pulmonary hypertensive crisis and volume overload in patients with persistent truncal valve regurgitation. Because of the lability of the pulmonary resistance vessels that may occur with and following elimination of elevated pulmonary blood flow at high pressures, pulmonary hypertensive crisis currently is less of an issue in early neonatal repair than it was with later repair. Nevertheless, patients may experience episodes of paroxysmal elevation of pulmonary vascular resistance.

Management with extended periods of anesthesia, including neuromuscular blockade and continuous fentanyl infusion, often is helpful. Ventilatory strategies aimed at minimizing pulmonary vascular resistance with supplemental oxygen and avoiding hypercarbia also may be effective. In refractory cases, inhaled nitric oxide or extracorporeal membrane oxygenation may be indicated.

After stabilization in the intensive care unit, removal from mechanical ventilatory and inotropic support, and discontinuation of intracardiac monitoring catheters, transfer the patient to the regular inpatient care area for advancement of feedings and additional postoperative care, depending on the experience and comfort level of the nursing staff on the ward.

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Consultations

Unless specific associated anomalies or problems are identified, consultations are not generally necessary.

Band 22q11 deletion is present in approximately one third of patients with truncus arteriosus, and consultation with a geneticist may be appropriate in some of these patients. Although patients with this chromosomal anomaly may have subtle associated abnormalities that are more likely to be identified if an experienced clinical geneticist is consulted, no evidence suggests that outcomes or management considerations differ in patients with or without chromosomal deletion.

When a chromosome 22q11 deletion is identified, comprehensive evaluation for associated conditions is indicated, including an otolaryngologist to evaluate for submucosal cleft palate, an immunologist to evaluate for immunodeficiency, and early intervention services for evaluation of learning and speech.

Consult a cardiologist before beginning, changing, or discontinuing cardiac medications in these patients.

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Diet

No special dietary considerations are indicated in patients with truncus arteriosus, other than a diet that might be dictated by associated conditions.

Resume enteral feeding once the patient is hemodynamically stable.

Resume oral feedings when the patient has been removed from mechanical ventilatory support and is adequately alert to take oral feedings safely. In patients with deletion in band 22q11, velopharyngeal insufficiency or cleft palate is frequently present, and oral feedings should be resumed with the aid of feeding specialists.

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Activity

Specific restrictions on activity are not indicated in patients with truncus arteriosus. Patients with repaired truncus arteriosus and either residual defects or regurgitation of the right ventricle to pulmonary artery conduit may have limited exercise capacity best addressed on an individual basis.

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Prevention

No known methods to prevent the development of truncus arteriosus in the fetus are known. On screening obstetric ultrasonography findings, 4-chamber and great vessel views are sufficient to identify that cardiac anomalies are present. In such an event, the parents should be referred for fetal echocardiography, with which the anatomy of truncus arteriosus can be more fully defined. Diagnosis in utero allows for greater parental choice, and may facilitate planned delivery at a tertiary care center and immediate neonatal stabilization, thus preventing the potential hemodynamic sequelae that can result from the natural history of the lesion.

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Long-Term Monitoring

For the early posthospital period, educate parents about the signs and symptoms of congestive heart failure, proper administration and potential adverse effects of any maintenance medications, and management of the sternotomy incision. For patient education resources, see the Heart Health Center.

Maintain close follow-up care in young children after repair of truncus arteriosus. Young infants are often discharged on cardiac medications and may usually be weaned over the following months.

Frequently, a mild degree of regurgitation occurs through the right ventricle–to–pulmonary arterial conduit but, in most cases, does not pose a significant load on the heart.

In most patients, conduit regurgitation and obstruction becomes an important issue after early repair; small conduits are utilized and become relatively stenotic with somatic growth or simple degeneration.

Truncal valve regurgitation, which may progress even if it was not severe before repair, may become an important cause of persistent failure to thrive, and repair or replacement of the valve may be indicated. [15]

In patients with associated interruption of the aortic arch, pay particular attention to potential recurrent arch obstruction and compression of the bronchi, both of which may manifest within weeks or months of the initial repair.

Routine clinical and echocardiographic follow-up care is sufficient to monitor most patients. Cardiac catheterization may be performed for the purpose of balloon dilation, stenting, or both of the pulmonary arteries or pulmonary outflow conduit, for evaluation of the pulmonary vascular bed in patients who are older and have evidence of pulmonary hypertension, or for other diagnostic indications according to the preference of the physicians.

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