Transcatheter heart valve with micro-anchors
Methods and devices for treating defective heart valves are disclosed herein. In one exemplary embodiment, a transcatheter heart valve includes an expandable shape memory stent and a valve member supported by the stent. A plurality of micro-anchors can be disposed along an outer surface of the stent for engaging native tissue. The transcatheter heart valve can be configured to be advanced into a dilated valve annulus via a balloon catheter. The balloon can be inflated to expand the transcatheter heart valve from a collapsed diameter to an over-expanded diameter such that the micro-anchors engage tissue along the surrounding valve annulus. After engaging the tissue, the balloon can be deflated and the shape memory stent can retract or recoil toward its predetermined recoil diameter. As the stent recoils, the surrounding tissue is pulled inward by the stent such that the diameter of the valve annulus is reduced.
1. A method of treating a heart valve, comprising:
compressing a prosthetic heart valve for advancement through a patient's vasculature, the prosthetic heart valve having a self-expandable support structure and a flexible valve member, the support structure comprising a shape memory material and having an outer surface with one or more projections extending radially outward therefrom, wherein the support structure is formed to have a memorized expanded diameter when the support structure is not acted on by any external force;
positioning the prosthetic heart valve within a patient's native heart valve, the native heart valve having an original diameter before treatment;
expanding the prosthetic heart valve from a compressed diameter to the memorized expanded diameter;
further expanding the prosthetic heart valve from the memorized expanded diameter to an over-expanded diameter that is larger than the memorized expanded diameter, thereby causing the one or more projections on the outer surface of the support structure to engage native tissue of the patient's native heart valve; and
allowing the prosthetic heart valve to retract from the over-expanded diameter toward the memorized expanded diameter while the one or more projections are engaged with the native tissue of the patient's native heart valve and wherein the prosthetic heart valve pulls inward on the native heart valve such that a final diameter of the native heart valve is smaller than the original diameter of the native heart valve after the prosthetic heart valve has retracted toward the memorized expanded diameter.
2. The method of claim 1 , wherein expanding the prosthetic heart valve from the compressed diameter to the memorized expanded diameter comprises deploying the prosthetic heart valve from a delivery sheath and allowing the prosthetic heart valve to self-expand.
3. The method of claim 1 , wherein the native heart valve is the native aortic valve.
4. The method of claim 1 , wherein the native heart valve is the native mitral valve.
5. The method of claim 1 , wherein positioning the prosthetic heart valve comprises advancing the prosthetic heart valve to the native heart valve transapically.
6. The method of claim 1 , wherein positioning the prosthetic heart valve comprises advancing the prosthetic heart valve to the native heart valve transfemorally.
7. The method of claim 1 , further comprising, after the one or more projections are caused to engage native tissue of the patient's native heart valve, changing the configuration of at least one of the one or more projections, thereby more securely engaging the at least one projection with the native tissue.
8. The method of claim 7 , wherein a delayed release mechanism causes the changing of the configuration of the at least one projection.
9. The method of claim 8 , wherein the delayed release mechanism is a resorbable material incorporated into the projection, and wherein the changing of the configuration of the at least one projection occurs as the resorbable material is resorbed by the patient's body.
10. The method of claim 1 , wherein the act of further expanding comprises inflating a balloon of a balloon catheter around which the prosthetic heart valve is disposed.
11. A method of treating a heart valve, comprising:
compressing a prosthetic heart valve for advancement through a patient's vasculature, the prosthetic heart valve having a support structure and a flexible valve member, the support structure having an outer surface with one or more projections configured to extend radially outward therefrom;
positioning the prosthetic heart valve within a patient's native heart valve;
expanding the prosthetic heart valve, thereby causing the one or more projections on the outer surface of the support structure to engage native tissue of the patient's native heart valve; and
after the one or more projections are caused to engage native tissue of the patient's native heart valve, changing the configuration of at least one of the one or more projections, thereby more securely engaging the at least one projection with the native tissue;
wherein the support structure has a recoil diameter when the support structure is not acted on by any external force, wherein the native heart valve has a heart valve diameter, and wherein expanding the prosthetic heart valve comprises:
expanding the prosthetic heart valve to an over-expanded diameter that is larger than the recoil diameter; and
allowing the prosthetic heart valve to retract from the over-expanded diameter toward the recoil diameter while the one or more projections are engaged with the native tissue of the patient's native heart valve and wherein the prosthetic heart valve pulls inward on the native heart valve such that the heart valve diameter decreases as the prosthetic heart valve retracts.