Successful transcatheter closure of a Fontan fenestration with a bioabsorbable Biostar occluder

We report the successful closure of an extracardiac Fontan fenestration with a bio-absorbable device, which may be refenestrated by a transcatheter route when needed, in a 10-year-old boy. The patient presented with cyanosis two years after an extracardiac Fontan operation. Echocardiography revealed a moderate shunt from the Fontan circulation into the systemic circulation with a mean pressure gradient of 3-4 mmHg. Treadmill testing revealed a significant decrease in oxygen saturation (down to the low 50’s from a baseline level of 80-85%). Cardiac catheterization revealed normal pressure in the Fontan circuit. A temporary balloon occlusion test showed that the defect was suitable for permanent occlusion. The fenestration was then occluded by a bio-absorbable Biostar (NMT medical, Boston, USA) atrial septal occluder device. The oxygen saturation on room air increased up to 95% after closure.