Objective To assess the use of detachable coils as an alternative method to occlude interatrial communications after Fontan operations.

Design Descriptive clinical study of selected patients after Fontan operation with interatrial communications inappropriate for transcatheter umbrella occlusion.

Setting Tertiary paediatric cardiac referral centre.

Patients Seven patients after Fontan operation with residual interatrial communications of various types producing a right to left shunt.

Interventions Transcatheter placement of detachable coils with a diameter of 3 or 5 mm within the interatrial communication.

Results A total of 14 coils were successfully placed within persistent patent fenestrations of the interatrial baffle, residual leaks at the suture line between the patch material and the right atrial wall, and unusual venous interatrial communications. The mean (SD) aortic oxygen saturation increased from 88 (1.1)% (range, 86–89%) to 92 (1.3)% (range, 89–93%; p < 0.001) and the mean (SD) right atrial pressure rose from 9.7 (2) mm Hg (range, 6–11) to 10.6 (2.4) mm Hg (range, 6–13; p < 0.05) after coil implantation. In five patients, complete obliteration of the interatrial shunt was shown by angiography after coil implantation. At a mean (SD) follow up of 10 (4) months (range, 3–15) a residual interatrial shunt was detected by Doppler colour echocardiography in only one patient, and oxygen saturations ranged from 90% to 95% (mean, 92%). There were no late coil embolisations, thromboembolic events, or haemolysis in any patient.

Conclusions Detachable coils can be used successfully to occlude residual interatrial communications after the Fontan procedure. In selected cases, in whom intended transcatheter umbrella occlusion of residual interatrial leaks is not possible, the use of detachable coils might offer a safe alternative method to eliminate interatrial right to left shunting after the Fontan procedure.