Sealing member for prosthetic heart valve

An implantable prosthetic valve comprising:

• an annular frame comprising an inflow end and an outflow end and being radially collapsible and expandable between a radially collapsed configuration and a radially expanded configuration, the frame defining an axial direction extending from the inflow end to the outflow end;
• a leaflet structure positioned within the frame and secured thereto;
• and
• an annular outer skirt positioned around an outer surface of the frame, wherein the outer skirt comprises:
• an inflow edge portion secured to the frame at a first location;
• an outflow edge portion secured to the frame at a second location;
• an intermediate portion between the inflow edge portion and the outflow edge portion, wherein the intermediate portion comprises a plurality of circumferentially spaced, axially extending slits that define a plurality of skirt segments between each pair of slits, wherein each skirt segment comprises first and second opposing edge portions;
• and
• a plurality of tethers, wherein each tether is secured to the first edge portion of a skirt segment at a first end of the tether, extends across the second edge portion of the same skirt segment, and is secured to the frame or an adjacent skirt segment at a second end of the tether such that when the frame is expanded to the radially expanded configuration, the first edge portion is pulled in a circumferential direction toward the second edge portion by the tether.