[Interventional occlusion of interatrial communication after modified Fontan operation]

After modified Fontan operations various communications between the systemic and pulmonary venous returns may cause persistent or increasing postoperative cyanosis. Interventional closure of these right-to-left shunts may be necessary to eliminate hypoxemia and to reduce the risk of paradoxical embolic complications.

Eighteen patients with a mean age of 5.6 +/- 4.1 (2.5-17.5) years underwent interventional closure of a right-to-left shunt 17.4 +/- 15.8 (3-60) months after a modified Fontan operation. After test balloon occlusion fenestrations were closed in 13 patients using an Amplatzer Septal occluder (n = 7), a Rashkind PDA occluder (n = 3), a CardioSeal umbrella (n = 1) and detachable coils (n = 2). Residual leaks at the suture lines between the interatrial patch and the right atrial wall were closed using detachable coils and a Rashkind PDA occluder in 2 and 1 patients, respectively. In 3 patients intracardiac venous collateral channels were closed by means of detachable coils.

The mean aortic oxygen saturation increased from 85 +/- 4.5 (70-89)% to 91.4 +/- 2.8 (83-95)% (p < 0.001) breathing room air and the mean tunnel pressure rose from 10.7 +/- 1.8 (6-14) mmHg to 12.1 +/- 2.4 (6-16) mmHg (p < 0.001). Calculated Qs decreased from 5.15 +/- 2.1 (2.1-11.3) l/min/m2 to 3.6 +/- 1.0 (1.8-5.6) l/min/m2 (p < 0.001). Mixed venous saturation (66.4 +/- 7.4% vs 65 +/- 7%) and mean systemic arterial pressure (73 +/- 8 mmHg vs 73 +/- 9 mmHg) remained unchanged. In one patient an additional leak of the tunnel could not be closed because of an increase to more than 18 mmHg of the mean pressure in the lateral tunnel during balloon test occlusion. In 2 patients residual leaks after umbrella and coil occlusion of a fenestration and an additional venous collateral channel were closed by means of coils after 16 and 21 months, respectively. At a follow-up of 42 +/- 23 (7-99) months, mean oxygen saturation measured by pulse oxymetry was 93 +/- 2 (90-97)%. In 2 patients color-coded Doppler echocardiography revealed a minimal residual right-to-left shunt. In 2 patients contrast echocardiography demonstrated the additional presence of intrapulmonary fistulas. All patients remained free from device migration, thromboembolic events and hemolysis.

After modified Fontan operations various right-to-left shunts between the systemic and pulmonary venous returns can be successfully closed using umbrella devices or coils to eliminate cyanosis and to reduce the risk of paradoxical embolism.