ABSTRACT
Introduction Most secundum type of atrial septal defects (ASD) are amenable for transcatheter closure. The Amplatzer Septal Occluder (ASO) is a unique device that combines the advantage of being a double-disk device with a self-centering mechanism.1 It is the first and only device to ever receive full approval in 2001 for clinical use from the United States Food and Drug Administration (FDA). Since its initial human use in 1995,2 it is now the most popular and effective device to close the ASD worldwide.
