Valve leaflet attachment in collapsible prosthetic valves
A prosthetic heart valve includes a stent having a collapsed condition and an expanded condition. The stent includes a plurality of cells, each cell being formed by a plurality of struts, and a plurality of commissure features. The heart valve further includes a valve assembly secured to the stent and including a cuff and a plurality of leaflets, each leaflet being attached to adjacent commissure features and to the stent struts and/or the cuff.
1. A prosthetic heart valve, comprising:
a stent having a collapsed condition and an expanded condition, the stent extending in a longitudinal direction between a proximal end and a distal end and including a plurality of cells, each cell being formed by a plurality of struts;
a plurality of commis sure features disposed on the stent; and
a valve assembly secured to the stent and including a cuff and a plurality of leaflets, each of the leaflets including a first edge and a second edge, the first edge having first ends and an intermediate portion between the first ends, the second edge having second ends and a free edge between the second ends, the free edge being spaced apart from the cuff, each of the leaflets being folded along a fold line at a spaced distance from the first edge to define a belly flap folded against a remaining portion of the leaflet, the fold line in the intermediate portion from one of the first ends to another of the first ends being directly sutured along an attachment line only to the cuff using whip stitches, each of the whip stitches including a first stitch pass in a first direction through the cuff only, and a second stitch pass in a second direction opposite the first direction through the cuff, the belly flap and the remaining portion of the leaflet.
2. The prosthetic heart valve as claimed in claim 1 , wherein each of the whip stitches is spaced from an adjacent whip stitch by between about 0.5 mm and about 2.0 mm.
3. The prosthetic heart valve as claimed in claim 1 , wherein each of the whip stitches has a bite size of between about 0.5 mm and about 2.0 mm.
4. The prosthetic heart valve as claimed in claim 1 , wherein the attachment line has a first end spaced between about 0.5 mm and about 2.0 mm proximal of a first one of the commissure features, and a second end spaced between about 0.5 mm and 2.0 mm proximal of a second one of the commis sure features.
5. The prosthetic heart valve as claimed in claim 1 , wherein the second ends of the second edge of each of the leaflets are attached to a respective pair of the commissure features.
6. The prosthetic heart valve as claimed in claim 5 , wherein the second ends of the second edge of each of the leaflets are attached to the cuff.
7. The prosthetic heart valve as claimed in claim 1 , wherein the attachment line includes a descending seam at a predetermined distance from one group of the struts and an ascending seam at the predetermined distance from another group of the struts.
8. The prosthetic heart valve as claimed in claim 7 , wherein the predetermined distance is about 2.0 mm or less.
9. The prosthetic heart valve as claimed in claim 7 , wherein the one group of the struts includes one of the struts from each of a first two of the cells.
10. The prosthetic heart valve as claimed in claim 9 , wherein the another group of the struts includes one of the struts from each of a second two of the cells, the second two of the cells being different from the first two of the cells.
11. The prosthetic heart valve as claimed in claim 7 , wherein the one group of the struts includes multiple struts connected to one another in a substantially end-to-end fashion.
12. The prosthetic heart valve as claimed in claim 11 , wherein the another group of the struts includes multiple struts connected to one another in a substantially end-to-end fashion.
13. The prosthetic heart valve as claimed in claim 1 , wherein each of the leaflets is folded so that the belly flap is positioned between the cuff and the remaining portion of the leaflet.
14. The prosthetic heart valve as claimed in claim 1 , wherein the spaced distance is between about 0.10 mm and about 2.0 mm.
15. The prosthetic heart valve as claimed in claim 1 , wherein each of the leaflets overlaps with a portion of the cuff to form a pocket between the cuff and each of the leaflets.