Right-to-left pulmonary shunting in pediatric hepatopulmonary syndrome

An 8-year-old boy with cavernous transformation of his portal vein and liver cirrhosis was hospitalized for cyanosis and polycythemia. A lung perfusion scan, performed with 10,000 particles Tc-99m-labeled MAA, showed a 37% right-to-left shunt. Chest CT showed no vascular malformations, and cardiac ultrasound showed no intracardiac shunt. A pulmonary arteriogram revealed innumerable tiny arteriovenous fistulae with extremely rapid transit of contrast to the pulmonary veins. A diagnosis of hepatopulmonary syndrome was made and he is awaiting liver transplantation.