TAPVC Total Anomalous Pulmonary Venous Connection

Total anomalous pulmonary venous connection (TAPVC) consists of an abnormality of blood flow in which all 4 pulmonary veins drain into systemic veins or the right atrium with or without pulmonary venous obstruction. Systemic and pulmonary venous blood mix in the right atrium. An atrial defect or foramen ovale (part of the complex) is important in left ventricular output both in fetal and in newborn circulation.

Clinical Findings of TAPVC

Hyperdynamic right ventricle

Fixed widely split second sound

Right atrial, right ventricular enlargement and right axis deviation.

Figure of eight appearance of cardiac shadow along with pulmonary plethora and enlarged pulmonary artery segment in X-ray chest.

Balloon Atrial Septostomy is done in

Transposition of great vessels

Total amomalous puomonary venous connections

Tricuspid atresia

Partial Anomalous Pulmonary Venous Connection

Partial anomalous pulmonary venous connection (PAPVC) is a rare congenital cardiac defect. As the name suggests, in PAPVC, the blood flow from a few of the pulmonary veins return to the right atrium instead of the left atrium. Usually, a single pulmonary vein is anomalous. Rarely, all the veins from one lung are anomalous. Thus, some of the pulmonary venous flow enters the systemic venous circulation.

Surgical Approach to PAPVC and TAPVC

Anomalous congenital connections of the pulmonary venous system represent a spectrum of conditions in which the pulmonary veins are partially or entirely connected to the right atrium, either directly or via the systemic venous return. Anomalous connection rather than “drainage” or “return” better describes the anatomical situation.

In the absence of a normal connection, an alternative pathway is formed to allow the egress of blood from the developing lung. This connection is usually to the right atrium (RA), or a systemic vein draining into the RA, thus creating a left-to-right shunt.

Patients with partial anomalous pulmonary venous connection (PAPVC) most commonly have an associated sinus venosus type atrial septal defect (ASD).

Patients with total anomalous pulmonary venous connection (TAPVC) most commonly present a confluence draining into a connecting vein to the systemic venous system. Less commonly, the pulmonary veins may drain to multiple sites (mixed pulmonary venous connection). Supply of oxygenated blood to the systemic circulation relies on an intracardiac right to left shunt in these patients.

Indications

Obstruction in the pulmonary venous pathway constitutes a surgical emergency in patients with total anomalous pulmonary venous connection (TAPVC). Medical measures aim at resuscitating and optimizing the patient’s clinical status until definitive repair and include intubation, hyperventilation with 100% oxygen, prostaglandin infusion, aggressive correction of pH, correction of all metabolic dysfunction, and inotropic support. The definitive therapeutic goal is complete relief of pulmonary venous obstruction and correction of the anomalous correction, which can be accomplished with only surgical repair.

In the absence of obstruction, surgery can be performed on an elective basis after diagnosis. Excellent clinical results are reported in infants, suggesting that little is gained by delaying surgical repair beyond age 4-6 months.

contraindications

Total anomalous pulmonary venous connection

No specific contraindications are noted for the repair of total anomalous pulmonary venous connection (TAPVC), although the surgical risk may be high in select groups of patients (eg, single ventricle, or heterotaxy syndromes).

Partial anomalous pulmonary venous drainage

In patients with partial anomalous pulmonary venous drainage (PAPVC) and an atrial septal defect (ASD), closure of the ASD may be inappropriate when pulmonary artery pressures are greater than two thirds the systemic pressure. Although rare, the presence of irreversible pulmonary hypertension is associated with systemic cyanosis. The surgical risk in this group of patients may be prohibitive.