Abstract: A pulmonary artery flow restrictor system includes a funnel shaped membrane with a proximal base, a restrictive distal opening which is stretchable to larger sizes, an internal strut structure, and an external stent structure.

Abstract: A retrievable stent configured to be positioned across the ductus arteriosus in a pediatric human patient to keep the ductus arteriosus open and ensure adequate blood flow is described. The retrievable stent can include a plurality of 4 to 8 struts that extend from a proximal end connector to a distal end tip, each having a curved proximal strut end, a curved distal strut end and an elongated strut body portion that extends from the curved proximal strut end to the curved distal strut end. When the stent is positioned in the ductus arteriosus, the curved proximal strut ends and the curved distal strut ends engage the ductus arteriosus to provide the radial force necessary to keep the ductus arteriosus open while the elongated strut body portions minimally engage the ductus arteriosus to prevent invagination into the vascular wall and thus allow for subsequent retrieval.