Venous valve prosthesis
A venous valve prosthetic implant for treatment of venous disease may include an expandable anchoring frame, a valve seat attached to the anchoring frame, a ball retention member attached to the anchoring frame, and a ball disposed within the lumen of the anchoring frame, between the valve seat and the ball retention member. The anchoring frame may include a first end, a second end, and a middle valve portion, where the middle valve portion expands to a smaller diameter than a diameter of either the first end or the second end. The ball may move back and forth within the middle valve portion, between a fully open position and a fully closed position.
1. A venous valve prosthetic implant for implantation in a vein for treatment of venous disease, the implant comprising:
one tubular expandable anchoring frame, consisting of a stent structure extending an entire length of the prosthetic implant, from an upstream end to a downstream end, and forming a lumen that extends through the anchoring frame from the upstream end to the downstream, wherein the expandable anchoring frame is expandable from a collapsed configuration, for delivery through a delivery catheter, to an expanded configuration outside of the delivery catheter, and wherein the anchoring frame has an hourglass shape with a narrow middle portion between the upstream end and the downstream end, both of which are wider than the middle portion;
a valve seat directly attached to an inner surface of the narrow middle portion of the anchoring frame, wherein the valve seat is expandable and collapsible;
a ball disposed within the lumen of the anchoring frame between the valve seat and the downstream end, such that the ball moves back and forth between the valve seat and the downstream end, between an open position, in which the ball is positioned to allow forward flow of blood through the implant, and a closed position, in which the ball contacts the valve seat to prevent backflow of blood through the implant; and
a ball retention tether comprising:
a first end directly attached to the ball; and
a second end directly attached to the anchoring frame at a location upstream from the ball.
2. An implant as in claim 1 , further comprising a coating disposed over at least a portion of the anchoring frame.
3. An implant as in claim 2 , wherein the coating is made of at least one substance selected from the group consisting of polymers, hyaluronic acid, heparin and anticoagulant agents.
4. An implant as in claim 2 , wherein at least one of the upstream end or the downstream end of the anchoring frame comprises a wider expandable portion that expands to a wider diameter than an immediately adjacent portion of the anchoring frame, and wherein the wider expandable portion forms multiple anti-migration tips when the anchoring frame is expanded.
5. An implant as in claim 4 , wherein the coating covers an entire surface area of the anchoring frame, other than the anti-migration tips.
6. An implant as in claim 1 , further comprising multiple anti-migration barbs on the anchoring frame, to prevent downstream movement of the implant within the vein.
7. An implant as in claim 1 , wherein the anchoring frame comprises a shape-memory material and is self-expandable from the collapsed configuration to the expanded configuration upon release from the delivery catheter.
8. An implant as in claim 1 , wherein an upstream end portion and a downstream end portion of the anchoring frame are sized to dilate the vein when the implant is implanted in the vein.
9. An implant as in claim 8 , wherein the middle portion of the anchoring frame is also sized to dilate the vein when the implant is implanted in the vein.
10. An implant as in claim 1 , wherein the middle portion of the anchoring frame has a straight tubular shape.
11. An implant as in claim 1 , wherein the middle portion of the anchoring frame has an hourglass shape.
12. An implant as in claim 1 , wherein the valve seat comprises an expandable and collapsible ring attached to an inner surface of the anchoring frame.
13. An implant as in claim 1 , wherein the ball retention tether is made of a material selected from the group consisting of a suture material and Nitinol.
14. An implant as in claim 1 , wherein the ball comprises a shell and a core.
15. An implant as in claim 14 , wherein the shell comprises a first material and the core comprises a second material.
16. An implant as in claim 14 , wherein the core comprises a magnetic material.
17. An implant as in claim 1 , wherein the ball has a ball diameter, and wherein a distance between the valve seat and the ball retention member is between two times and four times greater than the ball diameter.
18. An implant as in claim 1 , wherein the ball diameter is sized such that the ball contacts an inner surface of the anchoring frame as the ball travels back and forth within the anchoring frame, and wherein contact between the ball and the inner surface is configured to dislodge a substance attached to at least one of the inner surface, the valve seat, the ball, or the ball retention member.
19. An implant as in claim 1 , wherein the ball has a density of between 1.06 grams per cubic centimeter and 2.5 grams per cubic centimeter.
20. An implant as in claim 1 , wherein the ball comprises at least one surface feature configured to facilitate flow of blood around the ball, and wherein the surface feature is selected from the group consisting of dimples, slits and grooves.
21. An implant as in claim 1 , wherein the valve seat and the anchoring frame are compressible from outside of the implant to facilitate dislodging a substance attached to the implant.
22. An implant as in claim 1 , wherein the upstream end and the downstream of the anchoring frame expand to the same diameter.
23. A venous valve prosthetic implant for implantation in a vein for treatment of venous disease, the implant comprising:
one tubular expandable anchoring frame, consisting of a stent structure extending an entire length of the prosthetic implant, from an upstream end to a downstream end, and forming a lumen that extends through the anchoring frame from the upstream end to the downstream, wherein the expandable anchoring frame is expandable from a collapsed configuration, for delivery through a delivery catheter, to an expanded configuration outside of the delivery catheter, and wherein the anchoring frame has an hourglass shape with a narrow middle portion between the upstream end and the downstream end, both of which are wider than the middle portion;
a valve seat directly attached to an inner surface of the narrow middle portion of the anchoring frame, wherein the valve seat comprises an expandable and collapsible ring;
a ball disposed within the lumen of the anchoring frame between the valve seat and the downstream end, such that the ball moves back and forth between the valve seat and the downstream end, between an open position, in which the ball is positioned to allow forward flow of blood through the implant, and a closed position, in which the ball contacts the valve seat to prevent backflow of blood through the implant; and
a ball retention expandable wire anchor, comprising:
a first end directly attached to the ball; and
an expandable second end disposed upstream of the valve seat and having an expanded diameter wider than a diameter of the valve seat, such that the second end is wide enough that it cannot pass through the valve seat and is thus configured to prevent the ball from passing out of the valve prosthetic implant in a downstream direction.
24. An implant as in claim 23 , wherein the expandable second end of the ball retention expandable wire anchor has a V shape.
25. An implant as in claim 23 , wherein the ball retention expandable wire anchor is made of Nitinol.