The new Amplatzer Duct Occluder II Additional 
Sizes device is designed for the closure of small 
PDAs associated with small or shallow ductal 
ampullae. (2) The ADOIIAS, similar to its 
predecessor the ADOII, is made of nitinol braid and 
comprises two retention discs and a central portion 
that is designed to lie within the ductal lumen. The 
shape of the discs has been altered from curved to 
flat, and the retention discs have been reduced in size 
to minimize the risk of protrusion causing flow 
disturbance in the aorta or pulmonary artery