Surgical management of occluded conduits after the Fontan operation in patients with Glenn shunts.

Five complete conduit occlusions occurred in four patients with the Glenn shunt 2 months to 2 years after the Fontan operation. The possible reasons for complete conduit occlusion were severe dehydration, high pulmonary vascular resistance, and intraoperative manipulation of the conduit. In one patient in whom complete conduit occlusion developed twice, no possible cause could be identified. Surgical approaches included replacement of the occluded conduit in three patients and creation of an atrial septal defect and left aortopulmonary shunt in the fourth patient. All patients who had replacement of the occluded conduit survived. The fourth patient had severe cyanosis and hypoxemia from marked reduction of flow through the Glenn shunt because of reversal of flow through large venous collaterals. He subsequently died of Candida sepsis. A fifth patient (previously reported) who had complete conduit occlusion also died after a similar procedure. We believe that in patients with a Glenn shunt who develop complete conduit occlusion after the Fontan operation, conduit excision and a secondary Fontan operation, preferably without the use of woven Dacron, should be done instead of establishing an atrial septal defect and aortopulmonary shunt to the left lung.