Replacement heart valve having improved collapsible seal
Embodiments herein relate to cardiac stent-valves for transcatheter delivery. A cardiac stent-valve for transcatheter delivery is compressible to a compressed state for delivery and expandable to an expanded state for implantation. The stent-valve can include a stent with an axial inflow end and an axial outflow end, a plurality of leaflets arranged within the stent, and a structured sealing skirt for reduction or prevention of paravalvular leakage. The structured sealing skirt comprises one or more sealing formations arranged on a radially outer surface of the structured sealing skirt. At least in the expanded state, at least one of the one or more sealing formations is shaped and arranged such that, at each axial level of the structured sealing skirt covered by the one or more sealing formations. Other embodiments are also included herein.
1 . A cardiac stent-valve for transcatheter delivery, the stent-valve being compressible to a compressed state for delivery, and expandable to an expanded state for implantation, the stent-valve comprising:
a stent with an axial inflow end and an axial outflow end,
a plurality of leaflets arranged within the stent, and
a structured sealing skirt for reduction or prevention of paravalvular leakage;
wherein the structured sealing skirt comprises a first sealing formation and a second sealing formation, wherein the first sealing formation has a different shape than the second sealing formation, the first and second sealing formations being arranged on a radially outer surface of the structured sealing skirt, the first sealing formation comprising U-shaped repeating units;
wherein, at least in the expanded state, the first and second sealing formations are shaped and arranged such that, at each axial level of the structured sealing skirt covered by first and second sealing formations, the fraction of the radially outer surface occupied by the first and second sealing formations is less than 100%;
wherein the structured sealing skirt comprises a first sealing skirt end arranged towards the axial inflow end and a second sealing skirt end arranged towards the axial outflow end, wherein the first sealing formation is disposed adjacent to the first sealing skirt end and the first sealing formation follows a non-linear shape of the first sealing skirt end.
2 . The cardiac stent-valve of claim 1 , wherein the U-shaped repeating units alternate between an upper apex at a first axial height and a lower apex at a second axial height.
3 . The cardiac stent-valve of claim 2 , wherein each repeating unit extends between two adjacent upper apexes and/or two lower apexes.
4 . The cardiac stent-valve of claim 2 , wherein the stent comprises a lattice structure of diamond-shaped cells having axial apexes and wherein one or more of the upper apexes and/or the lower apexes of the U-shaped repeating units are axially offset to the axial apexes of the diamond-shaped cells.
5 . The cardiac stent-valve of claim 1 , wherein at least one of the first and second sealing formations extends continuously or intermittently at an angle of at least 180° along a circumference of the radially outer surface.
6 . The cardiac stent-valve of claim 1 , wherein at least one of the first and second sealing formations has a generally closed loop shape or a loop shape with one or more interruptions.
7 . The cardiac stent-valve of claim 1 , wherein at least one of the first and second sealing formations extends over at least 50% of an axial height of the structured sealing skirt.
8 . The cardiac stent-valve of claim 1 , wherein, in the expanded state, a height of at least one of the first and second sealing formations varies.
9 . The cardiac stent-valve of claim 1 , wherein, in the expanded state, at least one of the first and second sealing formations projects radially outward from the radially outer surface of the structured sealing skirt to a height of no more than 5 mm.
10 . The cardiac stent-valve of claim 1 , wherein the first and second sealing formations comprise material that is configured to expand or swell in response to contact with liquids.
11 . The cardiac stent-valve of claim 1 , wherein the first and second sealing formations comprise material chosen from open or closed cell porous material, wherein the open cell porous material is configured to facilitate endothelialization of the first and second sealing formations.
12 . The cardiac stent-valve of claim 1 , wherein the first and second sealing formations have a void content of more than 30%.
13 . The cardiac stent-valve of claim 1 , wherein the second sealing formation extends around the radially outer surface of the structured sealing skirt at a constant axial height.
14 . A cardiac stent-valve for transcatheter delivery, the stent-valve being compressible to a compressed state for delivery, and expandable to an expanded state for implantation, the stent-valve comprising:
a stent with an axial inflow end and an axial outflow end, the stent comprising a lattice structure of cells defined by interconnected struts,
a plurality of leaflets arranged within the stent, and
a structured sealing skirt for reduction or prevention of paravalvular leakage;
wherein the structured sealing skirt comprises one or more sealing formations being arranged on a radially outer surface of the structured sealing skirt,
wherein, at least in the expanded state, at least one of the one or more sealing formations comprises a meandering shape having repeat units, wherein the repeat units have a different circumferential dimension than the cell width of the lattice structure of the stent,
wherein the meandering shape has a variable shaped cross-section.
15 . The cardiac stent-valve of claim 14 , wherein the repeat units have a smaller circumferential dimension than the cell width of the lattice structure of the stent.
16 . The cardiac stent-valve of claim 14 , wherein the repeat units have a larger circumferential dimension than the cell width of the lattice structure of the stent.
17 . A cardiac stent-valve for transcatheter delivery, the stent-valve being compressible to a compressed state for delivery, and expandable to an expanded state for implantation, the stent-valve comprising:
a stent with an axial inflow end and an axial outflow end,
a plurality of leaflets arranged within the stent, and
a structured sealing skirt for reduction or prevention of paravalvular leakage;
wherein the structured sealing skirt comprises a first sealing formation and a second sealing formation, the first and second sealing formations being arranged on a radially outer surface of the structured sealing skirt at different axial heights,
the first sealing formation comprising U-shaped repeating units;
wherein, at least in the expanded state, the first and second sealing formations are shaped and arranged such that, at each axial level of the structured sealing skirt covered by first and second sealing formations, the fraction of the radially outer surface occupied by the first and second sealing formations is less than 100%;
wherein a cross-section of the first sealing formation is a different shape than a cross-section of the second sealing formation, wherein the cross-sections are taken parallel to a longitudinal axis of the cardiac stent-valve.
18 . The cardiac stent-valve of claim 17 , wherein at least one of first sealing formation and the second sealing formation has a cross-section that is asymmetric in the direction of the longitudinal axis of the cardiac stent-valve.
19 . The cardiac stent-valve of claim 17 , wherein one of the first sealing formation and the second sealing formation has an asymmetric cross-section in the direction of the longitudinal axis of the cardiac stent-valve and the other has a circular cross-section.