Stent features for collapsible prosthetic heart valves
A prosthetic heart valve includes a stent having an expanded condition and a collapsed condition. The stent includes a plurality of distal cells, a plurality of proximal cells, a plurality of support struts coupling the proximal cells to the distal cells, and at least one support post connected to a plurality of proximal cells. The proximal cells are longitudinally spaced apart from the distal cells. Various strut configurations and connections of the struts to the proximal cells and of the proximal cells to the support post improve stent flexibility and reduce stress in the valve leaflets.
1. A prosthetic heart valve, comprising:
a stent having a proximal end, a distal end, an expanded condition and a collapsed condition, the stent including:
a plurality of proximal cells at the proximal end;
a plurality of distal cells at the distal end, the distal cells being longitudinally spaced apart from the proximal cells;
a support strut array including a plurality of support struts, the array having a first end connected to a multiplicity of the proximal cells and a second end connected to a multiplicity of the distal cells, the multiplicity of the proximal cells being less than the multiplicity of the distal cells; and
at least one support post connected to the proximal cells; and
a valve structure connected to the at least one support post.
2. The prosthetic heart valve as claimed in claim 1 , wherein at least one of the support struts has a first end connected to one of the proximal cells and a second end connected to two of the distal cells.
3. The prosthetic heart valve as claimed in claim 1 , wherein, for each of the support posts connected to the proximal cells, there are two support struts each having a first end connected to one of the proximal cells and a second end connected to two of the distal cells.
4. The prosthetic heart valve as claimed in claim 3 , wherein each of the two support struts is immediately adjacent a respective one of the support posts.
5. The prosthetic heart valve as claimed in claim 1 , wherein the at least one support strut is a bifurcated support strut having a first end connected to one of the proximal cells and a second end connected to a plurality of the distal cells.
6. The prosthetic heart valve as claimed in claim 1 , wherein the support post has a first length when the stent is in the expanded condition and a second length less than the first length when the stent is in the collapsed condition.
7. A prosthetic heart valve, comprising:
a stent having a proximal end, a distal end, an expanded condition and a collapsed condition, the stent including:
a plurality of proximal cells at the proximal end;
a plurality of distal cells at the distal end, the distal cells being longitudinally spaced apart from the proximal cells;
a plurality of support struts, each support strut having a first end, a first end portion adjacent the first end, a second end, a second end portion adjacent the second end, and an intermediate portion between the first end portion and the second end portion, the first end of each support strut being connected to one of the distal cells and the second end of each support strut being connected to one of the proximal cells, the intermediate portions in a group of the plurality of support struts extending in a longitudinal direction in the collapsed condition of the stent and the second end portions in the group of the support struts extending at an oblique angle to the longitudinal direction in the collapsed condition of the stent; and
at least one support post connected to the proximal cells; and
a valve structure connected to the at least one support post.
8. The prosthetic heart valve as claimed in claim 7 , wherein the first end portions in the group of the support struts extend at an oblique angle to the longitudinal direction in the collapsed condition of the stent.
9. The prosthetic heart valve as claimed in claim 7 , wherein the first end portion of one of the support struts in the group of the support struts extends at a first oblique angle to the longitudinal direction in the collapsed condition of the stent and the first end portion of another of the support struts in the group of the support struts extends at a second oblique angle to the longitudinal direction in the collapsed condition of the stent, the second oblique angle being different than the first oblique angle.
10. The prosthetic heart valve as claimed in claim 7 , wherein the first end portion of one of the support struts in the group of the support struts extends at a first oblique angle to the longitudinal direction in the collapsed condition of the stent and the first end portion of another of the support struts in the group of the support struts extends at a second oblique angle to the longitudinal direction in the collapsed condition of the stent, the second oblique angle being the same as the first oblique angle.
11. The prosthetic heart valve as claimed in claim 7 , wherein select ones of the plurality of support struts are bifurcated struts, each of the bifurcated struts including a bifurcated section extending from the intermediate portion of the support strut to the first end of the support strut.
12. The prosthetic heart valve as claimed in claim 11 , wherein each of the bifurcated sections includes two branches oriented substantially parallel to one another in the collapsed condition of the stent.
13. The prosthetic heart valve as claimed in claim 7 , wherein the plurality of proximal cells collectively define a first end spaced from the proximal end of the stent, and each of the support posts has a distal end positioned closer to the distal end of the stent than the first end of the proximal cells.
14. The prosthetic heart valve as claimed in claim 7 , wherein the support post has a first length when the stent is in the expanded condition and a second length less than the first length when the stent is in the collapsed condition.
15. The prosthetic heart valve, comprising:
a stent extending in a longitudinal direction from a proximal end to a distal end and having an expanded condition and a collapsed condition, the stent including:
a plurality of proximal cells at the proximal end;
a plurality of distal cells at the distal end, the distal cells being longitudinally spaced apart from the proximal cells;
a plurality of support struts, each support strut having a first end connected to one of the distal cells at a first connection point and a second end connected to one of the proximal cells at a second connection point, the second connection point being laterally offset from the first connection point relative to the longitudinal direction; and
at least one support post connected to the proximal cells; and
a valve structure connected to the at least one support post.
16. The prosthetic heart valve as claimed in claim 15 , wherein each of the plurality of support struts includes a middle portion between the first end and the second end, the middle portion of at least one support strut having a sinusoidal configuration.
17. The prosthetic heart valve as claimed in claim 16 , wherein the sinusoidal configuration is offset laterally relative to the first end.
18. The prosthetic heart valve as claimed in claim 15 , wherein each of the plurality of support struts includes a middle portion between the first end and the second end, the middle portion of at least one support strut having a tapered configuration.
19. The prosthetic heart valve as claimed in claim 15 , wherein the support post has a first length when the stent is in the expanded condition and a second length less than the first length when the stent is in the collapsed condition.