Methods and apparatus for engaging a valve prosthesis with tissue
A prosthetic valve comprises a self-expanding frame which includes a self-expanding atrial skirt that forms a flanged region, a self-expanding ventricular skirt, and a first self-expanding tab coupled with the ventricular skirt. A receptacle for receiving a valve leaflet is formed by the area bounded by an outer surface of the atrial skirt, an outer surface of the ventricular skirt, and an inner surface of the first tab. The receptacle has a window for receiving the valve leaflet that is defined by a gap between an edge of the flange and a tip of the first tab. The gap is maximized when the tip of the first tab is unconstrained and a base of the first tab is at least partially constrained. The gap is minimized when the tip of the first tab and its base are unconstrained.
1. A self-expanding frame of a prosthetic valve, the frame comprising:
a superior end, an inferior end, and a midsection therebetween;
an atrial skirt adjacent the superior end;
a ventricular skirt adjacent the inferior end; and
a tab coupled to the ventricular skirt adjacent to the inferior end,
wherein the tab is configured to form a receptacle defined by an outer surface of the atrial skirt, an outer surface of the ventricular skirt, and the tab,
wherein, in a first partially-expanded configuration, the receptacle is configured to receive tissue,
wherein, in a second fully-expanded configuration, the receptacle is configured to anchor the frame to tissue, and
wherein the tab is configured to expand to a position transverse to a longitudinal axis of the frame in the first partially-expanded configuration.
2. The self-expanding frame of claim 1 , wherein the atrial skirt forms a flanged region after self-expansion, the flanged region configured to anchor the frame to an atrial surface of the heart.
3. The self-expanding frame of claim 2 , wherein:
the tab comprises a tip and a base;
in the first partially-expanded configuration, the tip of the tab is expanded radially outward relative to the base; and
in the second fully-expanded configuration, the base of the tab is expanded radially outward.
4. The self-expanding frame of claim 3 , wherein:
a window adapted for receiving the tissue is defined by a gap between an edge of the flange of the atrial skirt and the tip of the first tab; and
the gap is minimized in the second fully-expanded configuration.
5. The self-expanding frame of claim 4 , wherein, in the first partially-expanded configuration:
the gap is maximized; and
the window is adapted to receive the tissue in the receptacle.
6. The self-expanding frame of claim 3 , wherein the tab is configured to expand to a position substantially parallel to a longitudinal axis of the frame in the second fully-expanded configuration.
7. The self-expanding frame of claim 2 , wherein the atrial skirt is configured to expand before the tab expands.
8. The self-expanding frame of claim 2 , wherein the atrial skirt is configured to anchor the frame to the atrial surface before the tab anchors the frame to the tissue.
9. The self-expanding frame of claim 1 , further comprising a cover disposed at least partially over the self-expanding frame, the cover facilitating tissue ingrowth.
10. The self-expanding frame of claim 1 , wherein the receptacle is configured to receive and anchor the frame to a fibrous trigone.
11. The self-expanding frame of claim 1 , wherein the receptacle is configured to receive and anchor the frame to a mitral valve leaflet.
12. The self-expanding frame of claim 1 , wherein the receptacle is configured to receive and anchor the frame to a tricuspid valve leaflet.
13. A system for deploying a prosthetic valve, said system comprising:
a prosthetic cardiac valve comprising:
an atrial skirt;
a ventricular skirt;
and a tab coupled to the ventricular skirt; and
a delivery system configured to receive the prosthetic cardiac valve, the delivery system comprising:
an outer sheath; and
a pusher element slidably disposed inside the outer sheath,
wherein:
partial retraction of the outer sheath releases a first constraint from and allows self-expansion of the atrial skirt and the ventricular skirt;
further retraction of the outer sheath releases a constraint from the tab;
a tip of the tab radially self-expands outward forming a window between an edge of the atrial skirt and the tip of the tab,
a base portion of the tab is constrained by the outer sheath; and
actuation of the pusher element into engagement with the base portion engages the tip of the tab to open the window to its maximum size, and
further retraction of the outer sheath or further actuation of the pusher element removes a second constraint from the base portion of the tab to at least partially close the window.
14. The system of claim 13 , wherein:
the base portion self-expands radially outward when the second constraint is released; and the tip of the tab moves toward the edge of the atrial skirt to close the window.
15. The system of claim 13 , further comprising a cover disposed at least partially over the prosthetic cardiac valve and configured to facilitate tissue ingrowth.
16. The system of claim 15 , wherein the cover comprises fabric, tissue, or a polymer.
17. The system of claim 13 , wherein the tip of the tab is adapted to engage a fibrous trigone.
18. The system of claim 13 , wherein the tab is adapted to engage an anterior or a posterior leaflet of a mitral or tricuspid valve.