Transcatheter valve prosthesis having an external skirt for sealing and preventing paravalvular leakage

1. A transcatheter valve prosthesis comprising:

a stent extending along a longitudinal axis between an inflow end and an outflow end, the stent having a compressed configuration for delivery within a vasculature and an expanded configuration for deployment within a native heart valve, the stent including a plurality of crowns and a plurality of struts with each crown being a curved segment extending between a pair of opposing struts, the curved segment being curved between a first end and a second end thereof, wherein the first end of the curved segment extends from a first strut of the pair of opposing struts and the second end of the curved segment extends from a second strut of the pair of opposing struts, wherein the plurality of crowns and the plurality of struts define a plurality of openings of the stent and the stent has endmost crowns and endmost openings formed at the inflow end thereof, wherein all of the endmost crowns are disposed at a substantially similar longitudinal position when the stent is in the expanded configuration and all of the endmost crowns are disposed about a circumference of the inflow end of the stent, all of the endmost crowns forming the inflow end at the substantially similar longitudinal position at a longitudinal end of the stent,

an interior skirt coupled to and covering an inner circumferential surface of the stent;

a prosthetic valve component disposed within and secured to the interior skirt; and

an exterior skirt coupled to and covering an outer circumferential surface of the stent, the exterior skirt longitudinally extending over at least the endmost openings of the stent, wherein when the stent is in at least the compressed configuration at least one endmost crown is configured to be positioned radially inwards with respect to the remaining endmost crowns formed at the inflow end of the stent, thereby forming a circumferentially-extending gap between the endmost crowns adjacent to the at least one endmost crown positioned radially inwards in order to accommodate the exterior skirt, and wherein a first distance separating the longitudinal axis and the at least one endmost crown positioned radially inwards is less than a second distance separating the longitudinal axis and the remaining endmost crowns.

2. The transcatheter valve prosthesis of claim 1 , wherein when the stent is in the expanded configuration the at least one endmost crown is configured to be positioned radially inwards with respect to the remaining endmost crowns formed at the inflow end of the stent, and wherein a plane perpendicular to the longitudinal axis at the inflow end is adjacent to the endmost crowns.

3. The transcatheter valve prosthesis of claim 1 , wherein when the stent is in the expanded configuration the at least one endmost crown is configured to be positioned radially inwards a distance of between 0.5 and 1.5 millimeters from the remaining endmost crowns formed at the inflow end of the stent.

4. The transcatheter valve prosthesis of claim 1 , wherein every third endmost crown is configured to be positioned radially inwards with respect to the remaining endmost crowns formed at the inflow end of the stent.

5. The transcatheter valve prosthesis of claim 1 , wherein at least the struts that form the endmost opening adjacent to the at least one endmost crown are configured to bend radially inwards in order to position the at least one endmost crown radially inwards with respect to the remaining endmost crowns formed at the inflow end of the stent such that the struts adjacent to the at least one endmost crown and the at least one endmost crown are bent radially inwards with respect to the remaining endmost crowns.

6. The transcatheter valve prosthesis of claim 5 , wherein the interior skirt longitudinally extends over the endmost openings of the stent to the prosthetic valve component.

7. The transcatheter valve prosthesis of claim 6 , wherein the exterior skirt longitudinally extends over only the endmost openings of the stent, and wherein the exterior skirt is disposed within the circumferentially-extending gap when the stent is in the compressed configuration.

8. The transcatheter valve prosthesis of claim 1 , wherein the interior skirt and the exterior skirt are formed from the same material.

9. The transcatheter valve prosthesis of claim 1 , wherein the interior skirt and the exterior skirt are formed from different materials.

10. A transcatheter valve prosthesis comprising:

a stent having a compressed configuration for delivery within a vasculature and an expanded configuration for deployment within a native heart valve, the stent including a plurality of crowns and a plurality of struts with each crown being a curved segment extending between a pair of opposing struts, the curved segment being curved between a first end and a second end thereof, wherein the first end of the curved segment extends from a first strut of the pair of opposing struts and the second end of the curved segment extends from a second strut of the pair of opposing struts, wherein the plurality of crowns and the plurality of struts define a plurality of openings of the stent and the stent has endmost crowns and endmost openings formed at an inflow end thereof, wherein all of the endmost crowns are disposed at a substantially similar longitudinal position when the stent is in the expanded configuration and all of the endmost crowns are disposed about a circumference of the inflow end of the stent;

a skirt coupled to and covering an outer circumferential surface of an inflow end of the stent, the skirt longitudinally extending over at least the endmost openings of the stent; and

a prosthetic valve component disposed within and secured to the stent, wherein when the stent is in at least the compressed configuration at least one endmost crown is configured to be positioned radially inwards with respect to a first endmost crown adjacent to and on a first side of the endmost crown positioned radially inwards and a second endmost crown adjacent to and on an opposing second side of the endmost crown positioned radially inwards, and wherein the endmost crown positioned radially inwards is substantially similar in structure to the first endmost crown and the second endmost crown.

11. The transcatheter valve prosthesis of claim 10 , wherein when the stent is in the expanded configuration the at least one endmost crown is configured to be positioned radially inwards with respect to the remaining endmost crowns formed at the inflow end of the stent, and wherein a linear axis intersects the first endmost crown, the second endmost crown, and the endmost crown positioned radially inwards.

12. The transcatheter valve prosthesis of claim 10 , wherein every third endmost crown is configured to be positioned radially inwards with respect to the remaining endmost crowns formed at the inflow end of the stent.

13. The transcatheter valve prosthesis of claim 10 , further comprising a second skirt coupled to and covering an inner circumferential surface of the stent.

14. The transcatheter valve prosthesis of claim 10 , wherein the skirt is also coupled to and covers an inner circumferential surface of the stent.

15. A transcatheter valve prosthesis comprising:

a stent having a compressed configuration for delivery within a vasculature and an expanded configuration for deployment within a native heart valve, the stent including a plurality of crowns and a plurality of struts with each crown being a curved segment extending between a pair of opposing struts, the curved segment being curved between a first end and a second end thereof, wherein the first end of the curved segment extends from a first strut of the pair of opposing struts and the second end of the curved segment extends from a second strut of the pair of opposing struts, wherein the plurality of crowns and the plurality of struts define a plurality of openings of the stent and the stent has endmost crowns and endmost openings formed at an inflow end thereof, wherein all of the endmost crowns are disposed at a substantially similar longitudinal position when the stent is in the expanded configuration and all of the endmost crowns are disposed about a circumference of the inflow end of the stent; and

a prosthetic valve component disposed within and secured to the stent, wherein when the stent is in at least the compressed configuration at least one endmost crown is configured to be positioned radially inwards with respect to the remaining endmost crowns formed at the inflow end of the stent, thereby forming a circumferentially-extending gap between the endmost crowns adjacent to the at least one endmost crown positioned radially inwards, the circumferentially-extending gap extending in a circumferential direction between two endmost crowns that are directly adjacent to the at least one endmost crown positioned radially inwards.

16. The transcatheter valve prosthesis of claim 15 , wherein when the stent is in the expanded configuration the at least one endmost crown is configured to be positioned radially inwards with respect to the remaining endmost crowns formed at the inflow end of the stent.

17. The transcatheter valve prosthesis of claim 15 , wherein every third endmost crown is configured to be positioned radially inwards with respect to the remaining endmost crowns formed at the inflow end of the stent.

18. The transcatheter valve prosthesis of claim 15 , further comprising a skirt coupled to and covering at least an outer circumferential surface of an inflow end of the stent, the skirt longitudinally extending over at least the endmost openings of the stent and wherein a width of the circumferentially-extending gap is substantially equal to a width of the at least one endmost crown positioned radially inwards.