Data on long-term follow-up for closure of so-called secundum type“ atrial septal defects within the oval fossa using recently developed devices are limited, and results focused on presence of residual shunting. The purpose of our study was to report the experience from a single center establishing the effectiveness of transcatheter closure in patients with various types of defect other than those located centrally within the oval fossa.

A total of 72 patients was included in this study. On transesophageal echocardiography, the size of the defects varied from 6 to 18 mm, with estimation of the stretched diameter from 11 to 21 mm. The ratio of stretched diameter to the extent of the residual septum ranged from 0.28 to 0.54. Mean follow-up was 30.5+ 7.4 months, with a range from 13 to 42 months. The rate of closure using devices with diameters from 28 to 40 mm increased from 80% immediately after implantation to 93% in the 57 patients examined 24 months after implantation. For further analysis, we compared the 44 patients with a solitary, centrally located, defect to 28 having morphological variations, including superiorly located defects with deficient superior and aortic rims, multifenestrated and aneurysmal defects, or isolated additional defects. There was no incidence of formation of thrombus, sustained atrial arrhythmia, or infective endocarditis. Residual shunting was not influenced by location or morphology of the defects, but increased with size, stretched diameter, and the ratio of pulmonary to systemic flows. Serial transthoracic echocardiographic findings revealed malposition of one right-sided superior arm of the device in 8 patients, while protrusion of one leftsided arm onto the right atrial aspect was observed in 3 patients. Fluoroscopy showed fatigue fracture of a single arm in 7 patients (9.7%) within the first 6 months after implantation.

These results demonstrate that transcatheter closure with the non self-centering double umbrella device was effective and safe on medium-term follow-up, and could be extended to defects within the oval fossa having various morphologies. Residual shunting resolved with time, and was not related to either morphology or the position of the device.