Buttoned Device Occlusion of Patent Ductus Arteriosus.

Buttoned device, consisting of a square-shaped occluder and a rhomboid-shaped counter-occluder can be implanted across patent ductus arteriosus (PDA) via relatively small sheaths. In a large multi-institutional study, successful device implantation was achieved in 98% of patients. Decrease in the pulmonary-to-systemic flow ratio occurred. Effective occlusion was demonstrated in 88% of patients. PDAs could be occluded irrespective of their shape (conical, tubular, or short), length (short or long), or diameter (small or large). During follow-up for 1 to 60 months, 3% of patients required reintervention to treat residual shunts with (1%) or without (2%) hemolysis. There was gradual reduction and disappearance of the residual shunt during follow-up. Despite these encouraging results, patients with residual shunts are at risk for developing bacterial endocarditis. Therefore, the device was modified by incorporating a folding plug over the button loop, which resulted in complete occlusion of PDA at implantation.