Methods and devices for delivery of prosthetic heart valves and other prosthetics
Prosthetic valves and their component parts are described, as are prosthetic valve delivery devices and methods for their use. The prosthetic valves are particularly adapted for use in percutaneous aortic valve replacement procedures. The delivery devices are particularly adapted for use in minimally invasive surgical procedures. The preferred delivery device includes a catheter having a deployment mechanism attached to its distal end, and a handle mechanism attached to its proximal end. A plurality of tethers are provided to selectively restrain the valve during deployment. A number of mechanisms for active deployment of partially expanded prosthetic valves are also described.
1. A method for deploying a prosthetic heart valve, comprising:
advancing a prosthetic heart valve through vasculature of a patient to a treatment site along a wall of a blood vessel, the prosthetic heart valve comprising (i) a tubular support structure comprising a plurality of expandable segments oriented along a periphery of the support structure, and (ii) a plurality of valve leaflets coupled with the plurality of segments, wherein each expandable segment is transformable between a first shape and a second, expanded shape, and wherein at least one expandable segment is restrained in the first shape by a restraining member;
removal of the restraining member from the at least one expandable segment such that the at least one expandable segment is free to spontaneously expand; and
after removal of the restraining member, expanding an expandable deployment mechanism a first amount of distance against the at least one expandable segment in the first shape to cause the at least one expandable segment to expand a second amount of distance from the first shape to the second, expanded shape in contact with the vessel, wherein the first amount of distance is shorter than the second amount of distance and the expanding of the expandable deployment mechanism stops before the at least one expandable segment expands to the second, expanded shape in contact with the vessel.
2. The method of claim 1 , wherein blood is free to flow through the expanded prosthetic heart valve when the expandable deployment mechanism is expanded therein.
3. The method of claim 1 , wherein the expandable deployment mechanism initially contacts only a center region of the at least one expandable segment.
4. The method of claim 1 , wherein the expandable deployment mechanism has an expanded diameter that is less than an expanded diameter of the tubular support structure.
5. The method of claim 4 , wherein the expanded diameter of the expandable deployment mechanism is 16 millimeters and the expanded diameter of the tubular support structure is about 21 millimeters.
6. The method of claim 1 , wherein the expandable deployment mechanism comprises a plurality of expandable elements and the at least one expandable segment is a first expandable segment, and wherein expanding the expandable deployment mechanism comprises expanding a first one of the plurality of expandable elements against the first expandable segment.
7. The method of claim 6 , further comprising expanding a second one of the expandable elements against a second expandable segment after expanding the first one of the expandable elements.
8. The method of claim 6 , wherein the expandable elements are each balloons.
9. The method of claim 6 , wherein expanding the expandable deployment mechanism comprises expanding each of the plurality of expandable elements together.
10. The method of claim 6 , wherein each of the expandable elements can be selectively expanded.
11. The method of claim 1 , wherein the prosthetic heart valve is advanced through the vasculature by a delivery catheter that further comprises the expandable deployment mechanism.
12. The method of claim 1 , wherein the prosthetic heart valve is advanced through the vasculature by a delivery catheter separate from a carrier that carries the expandable deployment mechanism.
13. The method of claim 1 , wherein the plurality of expandable segments are configured to spontaneously expand, the method further comprising allowing the expandable segments to spontaneously expand prior to expanding the expandable deployment mechanism, wherein the at least one expandable segment does not spontaneously expand when allowed to do so.
14. The method of claim 13 , wherein the expandable deployment mechanism comprises at least one balloon, and expanding the balloon causes the balloon to expand radially from a central axis of the tubular support structure.
15. A method for deploying a prosthetic heart valve, comprising:
advancing a prosthetic heart valve through vasculature of a patient to a treatment site along a wall of a blood vessel, the prosthetic heart valve comprising (i) a tubular support structure comprising a plurality of expandable segments oriented along a periphery of the support structure, and (ii) a plurality of valve leaflets coupled with the plurality of segments, wherein each expandable segment is transformable between a first shape and a second, expanded shape, and wherein each expandable segment is restrained in the first shape by a restraining member;
removal of the restraining member for each expandable segment such that each expandable segment is free to spontaneously expand; and
expanding an expandable deployment mechanism a first amount of distance against the plurality of expandable segments in the first shape to cause the plurality of expandable segments to expand a second amount of distance from the first shape to the second, expanded shape in contact with the vessel, wherein the first amount of distance is shorter than the second amount of distance and the expanding of the expandable deployment mechanism stops before the plurality of expandable segments spontaneously expand to the second, expanded shape in contact with the vessel.
16. The method of claim 15 , wherein the expandable deployment mechanism is a balloon coupled to an elongate member, the balloon configured to expand radially from about the periphery of the elongate member.
17. The method of claim 15 , wherein the expandable deployment mechanism is a single balloon.
18. The method of claim 15 , wherein blood is free to flow through the expanded prosthetic heart valve when the expandable deployment mechanism is expanded therein.
19. The method of claim 15 , wherein the plurality of expandable segments are configured to spontaneously expand, the method further comprising allowing the expandable segments to spontaneously expand prior to expanding the expandable deployment mechanism, wherein the plurality of expandable segments do not spontaneously expand when allowed to do so.