Vascular implant and delivery method
A vascular implant for replacing a native heart valve comprises a self expanding stent supporting a valve body having leaflets. The stent preferably comprises an anchoring structure configured to prevent the implant from passing through the valve annulus. For delivery, the implant is compacted within a delivery device and secured at one end. During delivery the implant is partially released from the delivery device, and positioning of the implant can be verified prior to full release. The implant can be at least partially resheathed and repositioned if desired.
1. A method of delivering a replacement valve to a native mitral valve and securing the replacement valve relative to a native mitral valve annulus, the native mitral valve positioned between a left atrium and a left ventricle, the method comprising:
delivering a replacement valve into a patient, the replacement valve comprising:
an expandable frame extending along a longitudinal axis between a first end and a second end, the frame comprising a non-circular cross section shaped to facilitate engagement with the native mitral valve annulus; and
a valve body attached to the expandable frame;
expanding the frame at the patient's native mitral valve annulus, wherein when the frame is in an expanded configuration:
the first end of the frame is located on a left atrial side of the native mitral valve annulus;
the second end of the frame is located on a left ventricular side of the native mitral valve annulus; and
a plurality of anchors connected to the frame extend away from the frame on the left ventricular side of the native mitral valve annulus, the plurality of anchors extending generally toward the first end of the frame and engaging tissue on the left ventricular side of the native mitral valve annulus radially outward from an inner edge of the native mitral valve annulus.
2. The method of claim 1 , wherein the frame comprises a D-shaped cross-section.
3. The method of claim 1 , wherein the frame comprises an anchoring feature that engages the left atrial side of the native mitral valve annulus when the frame is in the expanded configuration at the patient's native mitral valve annulus.
4. The method of claim 3 , wherein the anchoring feature extends radially outward relative to the longitudinal axis of the frame so that the first end of the frame is larger than the second end of the frame when the frame is in the expanded configuration at the patient's native mitral valve annulus.
5. The method of claim 1 , wherein the plurality of anchors extend radially outward from the frame when the frame is in the expanded configuration at the patient's native mitral valve annulus.
6. The method of claim 1 , wherein the plurality of anchors extend in a direction substantially parallel with the longitudinal axis of the frame when the frame is in the expanded configuration at the patient's native mitral valve annulus.
7. The method of claim 1 , wherein the plurality of anchors engage the left ventricular side of the native mitral valve annulus when the frame is in the expanded configuration at the patient's native mitral valve annulus.
8. The method of claim 1 , wherein the plurality of anchors atraumatically engage tissue on the left ventricular side of the native mitral valve annulus radially outward from an inner edge of the native mitral valve annulus when the frame is in the expanded configuration at the patient's native mitral valve annulus.
9. A method of delivering a replacement valve to a native mitral valve and securing the replacement valve relative to a native mitral valve annulus, the native mitral valve positioned between a left atrium and a left ventricle, the method comprising:
delivering a replacement valve into a patient's heart, the replacement valve comprising:
an expandable frame comprising a supra-annular portion, an intra-annular portion and a sub-annular portion, wherein the sub-annular portion comprises at least one anchor, and wherein the expandable frame has a collapsed configuration for delivery into the patient's heart and an expanded configuration for deployment within the patient's heart; and
a plurality of valve leaflets,
expanding the expandable frame to the expanded configuration, wherein when the frame is in the expanded configuration:
the supra-annular portion sits above the native mitral valve annulus on an atrial side of the native mitral valve annulus and engages tissue on the atrial side of the native mitral valve annulus;
the intra-annular portion sits inside of the native mitral valve annulus and conforms with and engages the native mitral valve annulus;
the sub-annular portion displaces native mitral valve leaflets; and
the at least one anchor of the sub-annular portion engages tissue on a ventricular side of the native mitral valve annulus, wherein the at least one anchor extends outwardly beyond an inner edge of the native mitral valve annulus and extends from a distal portion of the sub-annular portion.
10. The method of claim 9 , wherein the expandable frame has a non-circular cross section to approximate the cross-section of the native mitral valve annulus.
11. The method of claim 10 , wherein the expandable frame has a D-shaped cross-section.
12. The method of claim 9 , wherein at least a portion of the replacement valve is covered with a fabric or tissue-based liner.
13. The method of claim 9 , wherein the replacement valve is delivered through the patient's vasculature.
14. The method of claim 9 , further comprising radially expanding the supra-annular portion of the expandable frame by slidably moving an outer sheath away from the supra-annular portion thereby allowing radial expansion thereof.
15. The method of claim 14 , wherein the supra-annular portion self-expands when the outer sheath is removed therefrom.
16. The method of claim 9 , wherein the supra-annular portion comprises a plurality of anchors that engage tissue on the atrial side of the native mitral valve annulus.
17. The method of claim 9 , further comprising sealing the supra-annular portion to surrounding tissue to reduce the risk of paravalvular leaks.
18. The method of claim 9 , further comprising radially expanding the intra-annular portion by slidably moving an outer sheath away from the intra-annular thereby allowing radial expansion thereof.
19. The method of claim 18 , wherein the intra-annular portion self-expands when the outer sheath is removed therefrom.
20. The method of claim 9 , wherein the at least one anchor of the sub-annular portion comprises a plurality of circumferentially spaced-apart anchors, and the method comprises engaging the plurality of anchors of the sub-annular portion with tissue on the ventricular side of the native mitral valve annulus.
21. The method of claim 9 , further comprising radially expanding the sub-annular portion by slidably moving an outer sheath away from the sub-annular portion thereby allowing radial expansion thereof.
22. The method of claim 21 , wherein the sub-annular portion self-expands when the outer sheath is removed therefrom.
23. The method of claim 9 , wherein expanding the expandable frame to the expanded configuration does not obstruct a left ventricular outflow tract.
24. The method of claim 9 , wherein the replacement valve comprises a plurality of locking members, the method further comprising releasing the locking members from a delivery catheter.
25. The method of claim 24 , wherein the plurality of valve leaflets of the replacement valve comprises three valve leaflets.
26. The method of claim 9 , wherein the replacement valve has an open position in which the plurality of valve leaflets of the replacement valve are disposed away from one another, and the replacement valve has a closed position in which the plurality of valve leaflets of the replacement valve engage one another, and wherein blood flows freely through the replacement valve in the open configuration, and wherein retrograde blood flow across the replacement valve is substantially prevented in the closed configuration.