Prosthetic heart valve leaflet assemblies and methods

1 . A method of assembling a prosthetic heart valve including a leaflet assembly, comprising:

forming a plurality of leaflet sub-assemblies, each leaflet sub-assembly including a leaflet and a skirt, wherein each leaflet sub-assembly is formed by:

placing the skirt on one side of the leaflet such that the skirt extends along a curved cusp edge portion of the leaflet and two commissure tabs of the leaflet, wherein the skirt lies in an x-z plane defined by an x-axis and a z-axis, the x-axis extending from side to side of the skirt and the z-axis extending from an inflow end to an outflow end of the skirt, wherein the skirt comprises a middle portion extending between two end portions, wherein each of the two end portions of the skirt comprises a tab comprising a first flap and a second flap, the first flap connected to and extending upwardly in a direction of the z-axis from an upper end of the middle portion of the skirt, and the second flap extending laterally from the first flap in a direction of the x-axis such that the second flap is offset from the middle portion in the direction of the x-axis;

folding the two end portions of the skirt around corresponding commissures tabs of the leaflet, wherein folding the two end portions of the skirt around corresponding commissure tabs of the leaflet includes, for each end portion and corresponding commissure tab, folding the tab around the corresponding commissure tab such that the first flap of the tab covers a first side of the commissure tab and the second flap of the tab covers a second side of the commissure tab;

stitching each folded end portion to the corresponding commissure tab of the two commissure tabs to form a respective half commissure portion of the leaflet sub-assembly; and

stitching the skirt to the cusp edge portion of the leaflet;

forming the leaflet assembly by pairing each half commissure portion of each leaflet sub-assembly with a half commissure portion of another leaflet sub-assembly of the plurality of leaflet sub-assemblies to form a plurality of pairs of adjacent half commissure portions, and for each pair, stitching the adjacent half commissure portions to each other to form a commissure of the leaflet assembly; and

securing the leaflet assembly to a frame of the prosthetic heart valve via fastening each commissure to a commissure support portion of the frame.

2 . The method of claim 1 , further comprising, further securing the leaflet assembly to the frame of the prosthetic heart valve via fastening the skirt of each leaflet sub-assembly to struts of the frame, and wherein fastening the skirt of each leaflet sub-assembly to struts of the frame includes fastening the middle portion of the skirt of each leaflet sub-assembly to a plurality of interconnected struts of the frame that are arranged in a lattice-type pattern.

3 . The method of claim 1 , wherein fastening each commissure to a commissure support portion of the frame includes wrapping end portions of each commissure around a respective commissure support portion and stitching through the end portions of the commissure via one or more sutures and tying the one or more sutures together on an outer surface of the commissure support portion of the frame.

4 . The method of claim 1 , further comprising, for each end portion and corresponding commissure tab, folding the first flap over itself to form two overlapping layers of the first flap on the first side of the commissure tab and folding the second flap over itself to form two overlapping layers of the second flap on the second side of the commissure.

5 . The method of claim 1 , wherein the middle portion of the skirt of each leaflet sub-assembly is disposed on only the one side of a corresponding leaflet.

6 . A method of assembling a prosthetic heart valve including a leaflet assembly, comprising:

forming a plurality of leaflet sub-assemblies, each leaflet sub-assembly including a leaflet and a skirt, wherein each leaflet sub-assembly is formed by placing the skirt on one side of the leaflet such that the skirt extends along a curved cusp edge portion of the leaflet and two commissure tabs of the leaflet, folding two end portions of the skirt around corresponding commissures tabs of the leaflet, stitching each folded end portion to a corresponding commissure tab of the two commissure tabs to form a respective half commissure portion of the leaflet sub-assembly, and stitching the skirt to the cusp edge portion of the leaflet;

forming the leaflet assembly by pairing each half commissure portion of each leaflet sub-assembly with a half commissure portion of another leaflet sub-assembly of the plurality of leaflet sub-assemblies to form a plurality of pairs of adjacent half commissure portions, and for each pair, stitching the adjacent half commissure portions to each other to form a commissure of the leaflet assembly; and

securing the leaflet assembly to a frame of the prosthetic heart valve via fastening each commissure to a commissure support portion of the frame,

wherein each of the two end portions of the skirt includes a tab and wherein folding the two end portions of the skirt around corresponding commissure tabs of the leaflet includes, for each end portion and corresponding commissure tab, folding the tab around the corresponding commissure tab to form a first flap covering a first side of the commissure tab and a second flap covering a second side of the commissure tab, and

wherein each leaflet sub-assembly further includes a reinforcing strip and further comprising placing the reinforcing strip on a side of the skirt arranged opposite a side of the skirt placed on the leaflet such that the reinforcing strip extends along a curved portion of the skirt and each of two end portions of the reinforcing strip overlay a corresponding first flap of the skirt and stitching each folded end portion of the skirt to the corresponding commissure tab and a corresponding end portion of the two end portions of the reinforcing strip via a first stitch.

7 . The method of claim 6 , wherein folding the two end portions of the skirt around corresponding commissure tabs of the leaflet further includes, for each end portion of the skirt and corresponding commissure tab, folding a free end portion of the first flap back over itself to cover the corresponding end portion of the reinforcing strip and form two overlapping layers over the first side of the commissure tab and folding a free end portion of the second flap back over itself to form two overlapping layers over the second side of the commissure tab, and further comprising stitching the two overlapping layers over the first side of the commissure tab, the commissure tab, and the two overlapping layers over the second side of the commissure tab to one another via a second stitch.

8 . The method of claim 7 , wherein, for each pair of adjacent half commissure portions, stitching the adjacent half commissure portions to each other to form a commissure of the leaflet assembly includes stitching the adjacent half commissure portions to each other via a third stitch arranged adjacent to the first stitch, the third stitch extending through the corresponding end portion of the reinforcing strip of each leaflet sub-assembly.

9 . The method of claim 8 , wherein stitching the adjacent half commissure portions to each other via the third stitch includes extending the third stitch through the two overlapping layers over the first side of the commissure tab, the commissure tab, and the two overlapping layers over the second side of the commissure tab, for each half commissure portion of the pair of adjacent half commissure portions, and wherein the third stitch is arranged adjacent to the first stitch on a side of the first stitch that faces the second stitch.

10 . The method of claim 8 , wherein stitching the adjacent half commissure portions to each other via the third stitch includes extending the third stitch through the two overlapping layers over the first side of the commissure tab and the commissure tab, and not the two overlapping layers over the second side of the commissure tab, for each half commissure portion of the pair of adjacent half commissure portions, and wherein the third stitch is arranged adjacent to the first stitch on a side of the first stitch that is arranged opposite to a side of the first stitch that faces the second stitch.