Total anomalous pulmonary venous return

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Patient families can visit our total anomalous pulmonary venous return (TAPVR) for more information and answers to common questions.

Pathophysiology

Anomalous pulmonary venous drainage is defined as drainage of the pulmonary veins into systemic veins or into the right atrium rather than the left atrium. Anomalous pulmonary venous drainage can be total or partial. When anomalous drainage of the pulmonary veins is total, three main subtypes exist.

Supracardiac TAPVC is present when all of the pulmonary venous return enters a common confluence located posterior to the left atrium. Blood drains from the pulmonary venous confluence to the vertical vein (or cardinal vein) into the innominate vein, where it then enters the superior vena cava to mix with systemic venous return. The left atrium receives mixed systemic and pulmonary venous return via an atrial septal defect. Obstruction can occur anywhere along this path.

Intracardiac TAPVC is present when the pulmonary venous return enters a confluence as described above, which empties into the coronary sinus. Coronary venous return, pulmonary venous return, and systemic venous return empty into the right atrium. The left atrium receives mixed systemic and pulmonary venous return via an atrial septal defect.

Infracardiac TAPVC is present when the pulmonary venous confluence drains inferiorly to the ductus venosus, which empties into the inferior vena cava. The right atrium receives mixed systemic and pulmonary venous return. The left atrium is supplied by the right atrium via an atrial septal defect. Obstruction can occur anywhere along this path.

Repair of TAPVC is performed early in life. When obstruction is present, pulmonary artery hypertension results. Pulmonary congestion and cardiovascular collapse may ensue. Urgent surgical repair is essential in this subset of patients. 

Surgical technique

Repair of TAPVC requires cardiopulmonary bypass and aortic cross-clamping. Hypothermic circulatory arrest or antegrade cerebral perfusion is used to provide a bloodless field. With repair of supracardiac TAPVC, the posterior left atrial wall and anterior pulmonary venous confluence are opened and sewn together. The vertical vein is then ligated. Next, the atrial septum is reconstructed with a patch to enlarge the left atrial chamber size. With repair of intracardiac TAPVC, the coronary sinus is “unroofed” by incising across the coronary sinus ostium into the left atrium. The atrial septum is then reconstructed with a patch, allowing the pulmonary venous return to enter the left atrium directly. With repair of infracardiac TAPVC, the posterior left atrial wall and anterior pulmonary venous confluence are sewn together. The vein originally draining pulmonary venous blood to the ductus venosus is ligated. The atrial septum is next reconstructed with a patch to enlarge the left atrial chamber size.

Delayed sternal closure is sometimes required, especially in infants with obstruction preoperatively. Cardiopulmonary bypass time and aortic cross-clamp time required to complete repair are usually moderate.

Postoperative considerations

Preoperative obstruction with hemodynamic instability predicts a potentially more difficult postoperative course. Pulmonary artery hypertension episodes can occur. Inhaled nitric oxide can be helpful. Temporary ECMO support is occasionally required.

Invasive monitors used include arterial and central venous catheters. An LA line is used when needed for hemodynamic management. LA pressure acts as a surrogate for left ventricular end diastolic pressure, an excellent indicator of left ventricular performance. Non-invasive monitors include NIRS (near infrared spectroscopy) probes to assess adequacy of regional and global perfusion and traditional pulse oximetry. Vasoactive agents might include epinephrine and/ or milrinone. Numerous other agents are available and are tailored to the specific needs of the patient, targeting adequate oxygen delivery to the tissues of the body and optimization of cardiac output.

Excessive postoperative bleeding is an uncommon complication. Cardiac rhythm disturbances can occur. Atrioventricular conduction disturbances, atrial tachydysrhythmias, and sinus bradycardia are sometimes encountered. Pulmonary vascular resistance and pressure usually decrease gradually following repair, and extubation is often possible 5 days to 1 week after surgery. Length of hospital stay following repair averages 10 days to 3 weeks.