Aortic bioprosthesis and systems for delivery thereof
Embodiments of the present disclosure are directed to stents, valved-stents, and associated methods and systems for their delivery via minimally-invasive surgery.
1. A replacement valve for use within a human body, the replacement valve comprising:
a valve component; and
a stent component configured to house at least a portion of the valve component, wherein the stent component is configured to shift between a collapsed configuration and an expanded configuration, the stent component comprising:
a central, longitudinal stent axis;
an inflow end and an outflow end;
a lower anchoring crown comprising an at least partly conical body, wherein the lower anchoring crown defines the inflow end of the stent component;
an upper anchoring crown in communication with the lower anchoring crown and comprising an at least partly conical body,
wherein:
the at least partly conical body of the lower anchoring crown slopes outwardly in a direction of the inflow end,
the at least partly conical body of the upper anchoring crown slopes outwardly in a direction of the outflow end and thereafter extends to a free end of the upper anchoring crown;
and
an outflow stent section in communication with the upper anchoring crown and comprising:
at least a partly conical body; and
a plurality of stabilization arches configured to bear against an ascending aorta and align the stent-component with respect to the ascending aorta,
wherein:
each stabilization arch comprises a first base portion having a first thickness, a divergent portion that diverges away from the stent axis in a direction towards the outflow end in the expanded configuration, an arch apex inclined at an angle α 5 measured from the divergent portion in a direction towards the stent axis in the expanded configuration and having a second thickness, and a second base portion having a third thickness,
wherein the first thickness and the third thickness are equal and the second thickness is greater than the first thickness and is greater than the third thickness, and
wherein each first base portion of one stabilization arch is joined to the second base portion of an adjacent stabilization arch.
2. The replacement valve of claim 1 , wherein the stent component further comprises a commissural post section in communication with the upper anchoring crown, and the plurality of stabilization arches is in communication with the commissural post section.
3. The replacement valve of claim 1 , wherein the plurality of stabilization arches is configured to prevent tilting of the stent component and the valve component when implanted.
4. The replacement valve of claim 1 , wherein at least one stabilization arch of the plurality of stabilization arches comprises an asymmetric feature.
5. The replacement valve of claim 1 , wherein:
the stent component includes a lattice structure of interconnected open cells including peripheral cells defining an end of the stent component,
a first plurality of the peripheral cells being axially extended compared to a second plurality of the peripheral cells, to define a plurality of attachment elements configured for removable attachment to a delivery device, and
each attachment element including an open portion defined by an extension of the respective peripheral cell.
6. The replacement valve of claim 5 , wherein: the lower anchoring crown further comprises at least three cells which are axially elongated to form openings configured to enlarge when the stent component expands, and the lengths of the axially elongated cells are between about 2 and about 3 mm.
7. The replacement valve according to claim 1 , wherein:
the stent component further comprises at least one attachment element, and
the at least one attachment element has a form of an opening which is able to enlarge when the stent component expands.
8. The replacement valve of claim 1 , wherein: the upper anchoring crown slopes outwardly from an inner diameter D 2 to an outer diameter D 1 in the direction of the outflow end, an axial length (L 4 ) of the upper crown in an expanded configuration is between about 3 and about 4 mm, the outward slope of the upper anchoring crown is defined by an angle al, and al is between from about 40 degrees and about 50 degrees.
9. The replacement valve of claim 1 , wherein the upper and/or lower anchoring crown includes a substantially cylindrical section between the upper partly conical body and the lower partly conical body.
10. The replacement valve of claim 9 , wherein:
the substantially cylindrical section has an axial length of between about 4 mm and about 6 mm, and/or
the axial length of the substantially cylindrical section is at least 50% of the axial length of at least one of the lower or upper anchoring crown.
11. A system for replacing a valve within a human body, the system comprising:
a delivery device comprising:
an inner member comprising a guide wire lumen and a stent holder, and
an outer member comprising a sheath; and
a replacement valve for use within a human body, the replacement valve comprising:
a valve component, and
a stent component configured to house at least a portion of the valve, wherein the stent component is configured to shift between a collapsed configuration and an expanded configuration, the stent component comprising:
a central, longitudinal stent axis;
an inflow end and an outflow end;
a lower anchoring crown defining an at least partly conical body, wherein the lower anchoring crown defines the inflow end of the stent component;
an upper anchoring crown in communication with the lower anchoring crown and defining an at least partly conical body, wherein:
the at least partly conical body of the lower anchoring crown slopes outwardly in a direction of the inflow end, and
the at least partly conical body of the upper anchoring crown slopes outwardly in a direction of the outflow end; and
an outflow stent section defining an at least partly conical body and comprising a commissural post section and a stabilization arch section,
wherein:
the commissural post section is in communication with the upper anchoring crown;
the stabilization arch section comprises a plurality of stabilization arches in communication with the commissural post section and defines an at least partly conical body,
each stabilization arch comprises a divergent portion that diverges away from the stent axis in a direction towards the outflow end in the expanded configuration and an arch apex inclined at an angle α 5 measured from the divergent portion in a direction towards the stent axis in the expanded configuration, and
each stabilization arch includes a first base portion having a first thickness adjacent a first commissural post section and a second base portion having a second thickness adjacent to an adjacent second commissural post section,
wherein the arch apex of the stabilization arch has a third thickness which is greater than the first thickness and is greater than the second thickness, and
at least one attachment element for removable attachment to the delivery device, wherein:
the at least one attachment element is located at the inflow end of the stent component,
the inflow end is defined as an end toward a left ventricle when delivered from a transapical approach,
the at least one attachment element comprising an opening configured to enlarge when the stent component expands, and
the stent holder comprises at least one groove for receiving the at least one attachment element of the stent component.
12. The system according to claim 11 , wherein at least one stabilization arch of the plurality of stabilization arches comprises an asymmetric feature.
13. The system according to claim 11 , wherein the stent holder comprises ramp surfaces to facilitate the release of the stent component after removing the sheath from the stent.
14. The system according to claim 11 , wherein release of the stent component from the stent holder is facilitated by rotation of the stent holder relative to the at least one attachment element.
15. A replacement valve for use within a human body, the replacement valve comprising:
a valve component; and
a stent component configured to house at least a portion of the valve component, wherein the stent component is configured to shift between a collapsed configuration and an expanded configuration, the stent component comprising:
a central, longitudinal stent axis;
an inflow end and an outflow end;
an outflow stent section defining the outflow end and comprising a stabilization arch section and a commissural post section communicating with the stabilization arch section,
wherein:
the commissural post section defines supports for the valve component, and
the stabilization arch section comprises a plurality of stabilization arches and has an outer profile defined by a divergent portion that diverges away from the stent axis in a direction towards the outflow end in the expanded configuration and an arch apex inclined at an angle of divergence measured from the divergent portion in a direction towards the stent axis in the expanded configuration, and
each stabilization arch includes a first base portion having a first thickness adjacent a first commissural post section, the arch apex having a second thickness, and a second base portion having a third thickness adjacent a second commissural post section,
wherein the first thickness and the third thickness are equal and the second thickness is greater than the first thickness and is greater than the third thickness;
an anchoring section defining the inflow end; and
a first crown section communicating with the outflow stent section and with the anchoring section, wherein the first crown section comprises a first divergent portion that diverges outwardly in a direction towards the outflow end, the first crown section having a free end.
16. The replacement valve of claim 15 , wherein the first divergent portion comprises a narrow end communicating with the anchoring section.
17. The replacement valve of claim 16 , wherein (i) the angle of divergence of the first divergent portion with respect to an axis of the replacement valve is less than 60 degrees, and/or (ii) an axial length between the free end of the first crown section and the narrow end of the first divergent portion is less than 10 mm.
18. The replacement valve of claim 17 , wherein the axial length of said tubular portion is at least 1 mm.
19. The replacement valve of claim 15 , wherein the free end of the first crown section is proximal of the outflow end.
20. The replacement valve of claim 15 , wherein the stent further comprises a tubular portion extending proximally from a narrow end of the first divergent portion, the tubular portion having a divergence in an inclusive range of 0 degrees (no divergence) to 10 degrees with respect to an axis of the replacement valve.
21. The replacement valve of claim 20 , wherein the tubular portion is generally cylindrical with a divergence of 0 degrees.
22. The replacement valve of claim 15 , wherein the anchoring section comprises a second crown section comprising a second diverging portion diverging outwardly in a direction towards the inflow end, the second crown portion having a free end.
23. The replacement valve of claim 22 , wherein the free end of the second crown section defines the inflow end.
24. The replacement valve of claim 22 , wherein the second diverging portion has an angle of divergence with respect to the stent axis in a range of 10 to 20 degrees.
25. The replacement valve of claim 15 , further comprising at least one attachment element for attaching the replacement valve to a stent holder of a delivery system.