A 37-year-old man with tricuspid atresia, in whom a chronic right apical aspergilloma had stimulated formation of extensive aortopulmonary collateral circulation, suffered reversal of flow within his long-standing fistulous Glenn anastomosis. By reversing the flow through the pulmonary arteriovenous fistula and raising oxygen saturation in the right atrium, the acquired aortopulmonary collateral circulation prevented the increase in cyanosis which usually occurs when fistulous changes develop late after the Glenn operation.
