Successful percutaneous closure of spiral atrial septal defect

The case report of a 15-year-old patient with an unusual form of atrial septal defect is described. Echocardiography showed separation of the secundum and primum atrial septums due to abnormal posterior and leftward attachment of the primum septum into the roof of the left atrium. The morphology has been variably described as a ‘double’ atrial septum or ‘spiral’ atrial septal defect. Despite the technical challenge of this form of atrial septal defect, it was effectively closed by ensuring that all relevant septal structures were incorporated between the discs of the occlusion device. This was associated with a stable position and good medium-term outcome. This contrasts with the experience of others where device embolisation or technical failure has been described. LEARNING POINTS: The spiral atrial septal defect is characterised by an apparently ‘double’ atrial septum. Such atrial septal defects (ASDs) have been associated with a high rate of technical failure of transcatheter closure. 3D echocardiography assists in understanding the anatomy of the defect. Following deployment of the ASD occlusion device transoesophageal echocardiography is essential to ensure that both septum primum and secundum are between the occluder discs. Catheter closure can be successful if close attention is paid to the morphology of the defect and incorporation of margins within the discs of the septal occluder.