Total anomalous pulmonary venous connection (TAPVC) is a rare and heterogeneous anomaly that accounts for only 2 percent of congenital heart defects.¹ TAPVC is a condition in which all the pulmonary veins drain into one or several systemic veins instead of the left atrium (LA). Presence or absence of pulmonary venous obstruction is important for the immediate postnatal stability of newborns. Obstructed TAPVC is one of the few true emergencies in congenital heart surgery.

The first attempt at surgical repair was performed by Muller in 1951 by performing an anastomosis between the pulmonary vein and the LA.² In 1956 Lewis successfully corrected TAPVC by using hypothermia and inflow occlusion.³ The first successful repair with cardiopulmonary bypass was performed by Burroughs and Kirklin in 1956.⁴

Four anatomic subtypes of TAPVC are recognized based on the location of the anomalous pulmonary venous drainage: supracardiac (40–50 percent), cardiac (20–25 percent), infracardiac (10–15 percent), and miscellaneous or mixed (10 percent). In supracardiac TAPVC, the four pulmonary veins join at a venous confluence (remnant of the common pulmonary vein) behind the LA and typically drain superiorly and to the left of the midline as the vertical vein (Fig. 73-1). This vertical vein will typically connect to the left innominate (brachiocephalic) vein. It may also connect directly with the superior vena cava (SVC) or, rarely, with one of the tributaries of the SVC. In the cardiac form of TAPVC, all four pulmonary veins drain into the common pulmonary vein, which in turn drains into the coronary sinus (Fig. 73-2). In infracardiac TAPVC, there is a common pulmonary vein behind the heart, which passes through the diaphragm and connects to either the portal vein, the ductus venous, or, rarely, directly to the inferior vena cava (IVC) (Fig. 73-3). Miscellaneous or mixed-type TAPVC is a combination of one or more of the other three types.

The etiology of TAPVC is unknown. TAPVC is most often an isolated lesion. Polysplenia, asplenia, and cat’s eye syndrome can be seen associated with TAPVC. The presence of interatrial communication [atrial septal defect (ASD)] is necessary to sustain life. A patent foramen ovale (PFO) or patent ductus arteriosus (PDA) may also be present.

TAPVC is a mixing lesion in which pulmonary venous blood completely mixes with systemic venous blood and returns to the right atrium through a systemic vein with the presence of a left-to-right shunt. An unrestrictive right-to-left shunt (usually through an ASD or PFO) is necessary for left ventricular filling. Identical oxygen saturation in all chambers of the heart is very typical. Pulmonary venous obstruction is the most important determining factor for the severity of symptoms and emergency of the clinical presentation.

Severe congestive heart failure is common in many patients in the early days of life, and is usually associated with cyanosis. Failure to thrive and slowly developing heart failure can be seen within the first couple of months of life in the presence of unobstructed TAPVC. Infants with obstructed TAPVC are usually in critical condition.

Neonates with obstructed TAPVC will typically disclose normal heart size with gross pulmonary edema on chest x-ray. In neonates and small infants, the differential diagnosis should include surfactant deficiency, severe pneumonia and lymphangiectasia. Right ventricular hypertrophy is present on electrocardiogram (ECG). Prenatal echocardiography is suboptimal for the detection of TAPVC. Postnatal echocardiography will usually show large right-sided and small left-sided cardiac structures, and identify the anatomic subtype of TAPVC with accuracy. The features of supracardiac TAPVC can be defined by imaging left SVC flow. A large coronary sinus is usually present in the cardiac-type TAPVC. In the infradiaphragmatic-type TAPVC, the common pulmonary vein can usually be reliably defined as it courses through the diaphragm. Cardiac catheterization is no longer used in diagnosis. Although echocardiography is usually adequate for diagnosis, magnetic resonance imaging (MRI) with three-dimensional reconstruction may be valuable and used as a supplement (Fig. 73-4).