Percutaneous closure of large atrial septal defects with the Amplatzer Septal Occluder: technical overkill or recommendable alternative treatment?

To judge whether an Amplatzer Septal Occluder (ASO) can be used as a safe therapy instead of surgery for closure of large atrial septal defects > 25 mm in diameter, we report our experiences in 45 patients out of a cohort of 467 patients after successful ASO implantation within a period of 3 years. Median defect diameter was 28 mm (range 25-36), median age was 41.2 years (range 10.1-77.7 years). Body weight ranged from 33.5 to 112.0 kg (median 68 kg). Due to an inevitable reduction of the stent size with increasing distances of the discs fixed at the thicker part of the atrial septum in larger defects, we implanted devices 2-4 mm larger than the measured stretched diameter. Fluoroscopy times ranged from 2.0 to 24.4 minutes, with a median of 10.3 minutes. Follow-up studies were obtained after 48 hours and 1, 6, and 12 months, and then yearly. The median period of follow-up was 0.82 years (range 0.1-2.6). The complete occlusion rate was 91.1%. A trivial hemodynamically insignificant residual shunt remained in 8.9% of the patients. Three patients showed transient atrial tachyarrhythmias within the first 3 months after implantation and three remained in chronic atrial fibrillation. The excellent results in the short and medium term make Amplatzer device implantation a recommendable safe and effective alternative to surgery, even in selected cases with defects > 25 mm. Final judgement, however, is only possible after long-term follow-up.