Prosthetic valve with axially-sliding frames

1. Apparatus for use with a native valve that is disposed between an atrium and a ventricle of a heart of a subject, the apparatus comprising an implant, the implant comprising:

a valve frame, comprising a tubular portion that circumscribes a longitudinal axis of the valve frame so as to define a lumen along the axis, the tubular portion defining a plurality of valve-frame coupling elements disposed circumferentially around the longitudinal axis;

a plurality of prosthetic leaflets, coupled to the frame, disposed within the lumen, and arranged to provide unidirectional flow of blood from an upstream end of the lumen to a downstream end of the lumen;

an outer frame:

comprising a ring defined by a pattern of alternating peaks and troughs, the peaks being longitudinally closer to the upstream end of the lumen than to the downstream end of the lumen, and the troughs being longitudinally closer to the downstream end of the lumen than to the upstream end of the lumen, and the pattern of the ring having an amplitude longitudinally between the peaks and the troughs,

comprising a plurality of legs, each of the legs coupled to the ring at a respective trough, and

shaped to define a plurality of outer-frame coupling elements, each of the outer-frame coupling elements (i) coupled to the ring at a respective peak, and (ii) fixed with respect to a respective valve-frame coupling element,

wherein:

the tubular portion has (i) a compressed state in which the tubular portion has a compressed diameter, and (ii) an expanded state in which the tubular portion has an expanded diameter that is greater than the compressed diameter,

the fixation of the outer-frame coupling elements to the valve-frame coupling elements is such that compression of the tubular portion from the expanded state toward the compressed state such that the valve-frame coupling elements pull the outer-frame coupling elements radially inward: (i) reduces a circumferential distance between each of the outer-frame coupling elements and adjacent outer-frame coupling elements, and (ii) increases the amplitude of the pattern of the ring, and

in the compressed state of the tubular portion, a downstream end of each leg is longitudinally closer than the valve-frame coupling elements to the downstream end of the lumen, and an upstream flange of each leg is disposed longitudinally closer than the valve-frame coupling elements to the upstream end of the lumen.

2. The apparatus according to claim 1 , wherein the ring circumscribes the tubular portion.

3. The apparatus according to claim 1 , wherein the valve-frame coupling elements are disposed circumferentially around the longitudinal axis between the upstream end of the lumen and the downstream end of the lumen but not at the upstream end of the lumen nor at the downstream end of the lumen.

4. The apparatus according to claim 1 , wherein the outer frame is coupled to the valve frame only via the fixation of the outer-frame coupling elements to the respective valve-frame coupling elements.

5. The apparatus according to claim 1 , further comprising an upstream support portion that comprises a plurality of arms that extend radially from the tubular portion, wherein:

the upstream support portion has (i) a constrained-arm state, and (ii) a released-arm state in which the arms extend radially outward from the tubular portion,

each leg has (i) a constrained-flange state, and (ii) a released-flange state in which the flange extends radially outward from the tubular portion, and the implant has an intermediate state in which (i) the tubular portion is in the compressed state, (ii) the upstream support portion is in the released-arm state, and (iii) the legs are in the released-flange state.

6. The apparatus according to claim 5 , wherein

the apparatus further comprises a tool:

comprising a delivery capsule dimensioned (i) to house and retain the implant in a compressed-implant state of the implant in which (a) the tubular portion is in the compressed state, (b) the upstream support portion is in the constrained-arm state, and (c) the legs are in the constrained-flange state, and (ii) to be advanced percutaneously to the heart of the subject while the implant is housed and in the compressed-implant state, and

operable from outside the subject to:

transition the implant from the compressed-implant state into the intermediate state while retaining the tubular portion in the compressed state, and

subsequently, expand the tubular portion toward the expanded state.

7. The apparatus according to claim 6 , wherein the tool is operable from outside the subject to transition the implant from the compressed-implant state into the intermediate state by (i) releasing the legs into the released-flange state, while retaining the tubular portion in the compressed state, and (ii) subsequently, releasing the upstream support portion into the released-arm state, while retaining the tubular portion in the compressed state.

8. The apparatus according to claim 6 , wherein the tool is operable from outside the subject to transition the implant from the compressed-implant state into the intermediate state by (i) releasing the upstream support portion into the released-arm state, while retaining the tubular portion in the compressed state, and (ii) subsequently, releasing the legs into the released-flange state, while retaining the tubular portion in the compressed state.

9. The apparatus according to claim 5 , wherein the fixation of the outer-frame coupling elements to the valve-frame coupling elements is such that, when the implant is in the intermediate state, expansion of the tubular portion from the compressed state toward the expanded state moves the flanges longitudinally away from the valve-frame coupling elements.

10. The apparatus according to claim 5 , wherein the fixation of the outer-frame coupling elements to the valve-frame coupling elements is such that, when the implant is in the intermediate state, expansion of the tubular portion from the compressed state toward the expanded state reduces the amplitude of the pattern of the ring and passes the flanges between the arms.

11. The apparatus according to claim 10 , wherein the upstream support portion further comprises a covering that covers the arms to form an annular shape in the released-arm state, and wherein, when the implant is in the intermediate state, expansion of the tubular portion from the compressed state toward the expanded state presses the flanges onto the covering.

12. The apparatus according to claim 5 , wherein the upstream support portion comprises one or more fabric pockets disposed circumferentially, each pocket of the one or more pockets having an opening that faces a downstream direction.

13. The apparatus according to claim 1 , wherein in the expanded state of the tubular portion, the downstream end of each leg is longitudinally closer than the valve-frame coupling elements to the downstream end of the lumen, and the flange of each leg is disposed longitudinally closer than the valve-frame coupling elements to the upstream end of the lumen.

14. Apparatus for use with a native valve that is disposed between an atrium and a ventricle of a heart of a subject, the apparatus comprising:

a valve frame, comprising a tubular portion that circumscribes a longitudinal axis of the valve frame so as to define a lumen along the axis, the tubular portion defining a plurality of valve-frame coupling elements disposed circumferentially around the longitudinal axis;

a plurality of prosthetic leaflets, coupled to the frame, disposed within the lumen, and arranged to provide unidirectional flow of blood from an upstream end of the lumen to a downstream end of the lumen;

an outer frame:

comprising a ring defined by a pattern of alternating peaks and troughs, the peaks being longitudinally closer to the upstream end of the lumen than to the downstream end of the lumen, and the troughs being longitudinally closer to the downstream end of the lumen than to the upstream end of the lumen, and the pattern of the ring having an amplitude longitudinally between the peaks and the troughs,

comprising a plurality of legs, each of the legs coupled to the ring at a respective trough, and defining a flange at an upstream end of the leg, and

shaped to define a plurality of outer-frame coupling elements, each of the outer-frame coupling elements (i) coupled to the ring at a respective peak, and (ii) fixed with respect to a respective valve-frame coupling element,

wherein:

the tubular portion has (i) a compressed state in which the tubular portion has a compressed diameter, and (ii) an expanded state in which the tubular portion has an expanded diameter that is greater than the compressed diameter, and

the fixation of the outer-frame coupling elements to the valve-frame coupling elements is such that compression of the tubular portion from the expanded state toward the compressed state such that the valve-frame coupling elements pull the outer-frame coupling elements radially inward: (i) reduces a circumferential distance between each of the outer-frame coupling elements and adjacent outer-frame coupling elements, and (ii) increases the amplitude of the pattern of the ring.