Transcatheter occlusion (TCO) may be an alternative method for the surgical closure of a secundum atrial septal defect (ASD) below 20 mm in diameter. We performed this study in order to evaluate the safety and feasibility of an Amplatzer septal occluder for closing ASD bigger than 20 mm in diameter percutaneously.

Thirty three of 39 patients presenting with ASD were included in this study (3 patients with a large defect over 32mm and 3 with multiple defects were excluded). The median age was 8.6 years (2.2 - 54) and median weight was 27 kg (10.7 - 85). The mean defect size was 15±3 mm as measured by transthoracic echocardiogram, 17±5 mm by transesophageal echocardiogram, and 21±6 (11 - 32) mm by balloon stretched diameter. The balloon stretched diameter was larger than 20 mm in 20 of 33 patients. The mean Qp/Qs was 2.3±0.7. The mean device size was 22±6 mm and the mean fluoroscopic time was 13±7 min.

The device was successfully implanted in 29 of 33 patients. The 4 patients in which implantation failed showed a left disc protrusion into the right atrium. Three of these patients were treated surgically, and one underwent a successful second attempt of TCO 12 months after the first trial. Complete closure was obtained in 30 patients in follow-up. The complications encountered included;cobra-shaped deformity of the device (3), transient AV block (Wenckebach) (1), embolization of the radioopaque marker into the left atrial appendage (1), failure in the first device (1), and mild mitral regurgitation at 3 months follow-up due to device protrusion into the mitral valve (1).

The Amplatzer septal occluder appears to be a promising device for TCO of ASD up to 32 mm in diameter, however, long-term follow-up in a large number of patients is warranted.