Stent for the positioning and anchoring of a valvular prosthesis

1. An expandable stent for the positioning and anchoring of a valvular prosthesis in an implantation site, the stent comprising: a plurality of positioning arches configured to be positioned within a plurality of pockets of a native heart valve and positioned on a first side of a plurality of native heart valve leaflets, a plurality of retaining arches configured to be positioned on a second side of the plurality of native heart valve leaflets opposite the first side, and a plurality of radial arches, each radial arch substantially circumferentially aligned with one of the plurality of positioning arches, wherein respective arms of each of the plurality of retaining arches include a plurality of bending edges, each of the plurality of bending edges defining a bending point between two adjacent arm segments.

2. The expandable stent according to claim 1 , wherein each of the plurality of positioning arches includes a substantially U-shaped or V-shaped structure.

3. The expandable stent according to claim 1 , further including a collapsed mode when being introduced into a patient's body and an expanded mode when implanted.

4. The expandable stent according to claim 1 , wherein each of the plurality of positioning arches and the plurality of retaining arches consists essentially of three arches.

5. The expandable stent according to claim 1 , wherein each of the plurality of positioning arches and each of the plurality of radial arches includes a closed end, and the closed end of a respective positioning arch is substantially circumferentially aligned with respect to the closed end of an associated radial arch.

6. The expandable stent according to claim 5 , wherein the closed end of each of the plurality of retaining arches extends in a first axial direction of the stent and the closed end of each of the plurality of radial arches extends in a second axial direction of the stent, opposite the first axial direction.

7. The expandable stent according to claim 1 , further comprising a plurality of auxiliary arches, each interspaced between two adjacent retaining arches and including a first arm connected at a first end thereof to a first retaining arch and a second arm connected at a first end thereof to a second retaining arch, wherein the first and second arms of each of the plurality of auxiliary arches include respective second ends connected to at least one annular collar.

8. The expandable stent according to claim 1 , wherein each of the plurality of positioning arches includes first and second arms joined to one another at a head portion, and wherein the expandable stent further comprises a plurality of leaflet guard arches, each interspaced between the two arms of one of the plurality of positioning arches and including a first arm and a second arm, wherein the first and second arms of each of the plurality of leaflet guard arches are joined to one another at a head portion.

9. The expandable stent according to claim 8 , wherein each radial arch includes first and second arms joined to one another at a head portion.

10. The expandable stent according to claim 9 , wherein each of the plurality of radial arches is joined to a respective one of the plurality of leaflet guard arches.

11. The expandable stent according to claim 1 , further including at least one annular collar connected to each of the respective retaining arches.

12. The expandable stent according to claim 11 , further comprising a structure of lattice cells formed by a plurality of struts disposed circumferentially between respective arms of two adjacent retaining arches.

13. The expandable stent according to claim 11 , further comprising a plurality of notches uniformly distributed around a proximalmost portion of the at least one annular collar.

14. The expandable stent according to claim 1 , wherein a valvular prosthesis is connected to the stent via at least one suture.

15. The expandable stent according to claim 14 , wherein the valvular prosthesis is made from pericardium.

16. The expandable stent according to claim 1 , wherein each of the plurality of positioning arches includes first and second arms joined to one another at a head portion projecting toward a first end of the stent, and wherein each of the plurality of radial arches includes first and second arms joined to one another at a head portion projecting toward a second end of the stent, opposite the first end.

17. The expandable stent according to claim 16 , wherein the first and second arms of each radial arch include: a first portion extending in the first direction toward a head portion of a respective one of the plurality of positioning arches; and a second portion extending in the second direction away from the head portion of a respective one of the plurality of positioning arches; wherein the respective second portions of the first and second arms of each radial arch are connected to one another to form the head portion of the radial arch.

18. An expandable stent for the positioning and anchoring of a valvular prosthesis in an implantation site, the stent comprising:

a plurality of positioning arches configured to be positioned within a plurality of pockets of a native heart valve and positioned on a first side of a plurality of native heart valve leaflets, wherein each of the plurality of positioning arches includes first and second arms joined to one another at a head portion;

a plurality of retaining arches configured to be positioned on a second side of the plurality of native heart valve leaflets opposite the first side, wherein respective arms of each of the plurality of retaining arches include a plurality of bending edges, each of the plurality of bending edges defining a bending point between two adjacent arm segments and

a plurality of leaflet guard arches, each leaflet guard arch interspaced between the two arms of one of the plurality of positioning arches and including a first arm and a second arm, wherein the first and second arms of each of the plurality of leaflet guard arches are joined to one another at a head portion.

19. The expandable stent according to claim 18 , further including a plurality of radial arches, each radial arch substantially circumferentially aligned with one of the plurality of positioning arches, each radial arch including first and second arms joined to one another at a head portion.

20. The expandable stent according to claim 19 , wherein each of the plurality of radial arches is joined to a respective one of the plurality of leaflet guard arches.

21. An expandable stent for the positioning and anchoring of a valvular prosthesis in an implantation site, the stent comprising:

a plurality of positioning arches configured to be positioned within a plurality of pockets of a native heart valve and positioned on a first side of a plurality of native heart valve leaflets;

a plurality of retaining arches configured to be positioned on a second side of the plurality of native heart valve leaflets opposite the first side, wherein respective arms of each of the plurality of retaining arches include a plurality of bending edges, each of the plurality of bending edges defining a bending point between two adjacent arm segments and

at least one annular collar connected to each of the respective retaining arches.

22. The expandable stent according to claim 21 , further comprising a structure of lattice cells formed by a plurality of struts disposed circumferentially between respective arms of two adjacent retaining arches.

23. The expandable stent according to claim 21 , further comprising a plurality of notches uniformly distributed around a proximalmost portion of the at least one annular collar.