Figure 1. The catheter coiled within the dilated left portal vein, with its tip directed toward the left diaphragm (arrow).
Figure 2. Cineangiograms performed in the venous phases of selective right (Figure 2A, curved arrows) and left (Figure 2B, open arrows) pulmonary artery injections demonstrated separate right and left pulmonary venous channels crossing the left diaphragm to join and enter the left portal vein.
Of the many causes of cardiorespiratory distress in the neonate, total anomalous pulmonary venous return (TAPVR) is one of the most difficult to diagnose early. It constitutes 2% of all congenital cardiac defects and is an isolated lesion in two thirds of cases.1 There may be associated cardiac defects. Classified into 2 major forms,1 TAPVR is a congenital cardiac defect in which the pulmonary veins do not empty into the left atrium but anomalously drain into the right atrium. Blood flow is usually unobstructed when the common pulmonary vein connects with the superior vena cava, azygos vein, coronary sinus, or right atrium. Without obstructions to pulmonary venous return, the right side of the heart receives blood flow from the systemic and pulmonary venous systems. In the subdiaphragmatic form of TAPVR, there is almost always obstruction to blood flow.