A 9-month-old girl with biliary atresia, who had previously undergone the Kasai procedure, was referred for cardiac evaluation prior to transplantation of the liver. Her previous work-up included abdominal ultrasonic evaluation, which revealed interruption of the inferior caval vein, with polysplenia considered as part of the differential diagnosis. Physical examination was unremarkable except for jaundice, hepatomegaly, and a vibratory systolic murmur.

Echocardiography confirmed interruption of the inferior caval vein with hemiazygous continuation. Rather than the commonly seen drainage into a left superior caval vein, and thence to the coronary sinus, the venous return flowed cephalad into the brachiocephalic vein through an accessory hemiazygous channel and the left superior intercostal vein (red colour in Fig. 1), where it joined the flow through the brachiocephalic vein (blue colour in Fig. 1). The hepatic veins drained directly into the right atrium. Because of the unusual direction of flow toward the transducer in the brachiocephalic vein, careful attention was given to locating all pulmonary veins, and to proving that the coronary sinus was not atretic. Four pulmonary veins were clearly defined and shown to connect to the left atrium.

Figure 1.

The echocardiographic findings were confirmed by magnetic resonance imaging and magnetic resonance angiography. A volume-rendered magnetic resonance angiogram in an oblique-sagittal plane demonstrated the hemiazygous vein posterior to the aorta, and showed it continuing cephalad via the accessory hemiazygous and left superior intercostal veins to terminate in the brachiocephalic vein (Fig. 2).

Figure 2.

This unusual variant demonstrates the importance of identifying all central systemic and pulmonary venous channels. An interrupted inferior caval vein can drain via an azygous vein to the right superior caval vein, or via a hemiazygous vein to the left superior caval vein. Our case shows that it can also continue cephalad to terminate in the brachiocephalic vein,^{1, 2} a situation that mimicks the most common variant of supracardiac totally anomalous pulmonary venous connection to the brachiocephalic vein. Transplantation of the liver was more easily performed in this patient because there was no need for retrohepatic caval venous dissection. The new liver was sewn directly into the venous outflow tract of the recipient, with the azygous venous system acting as a bypass circuit to decompress the lower part of the body.