Prosthetic valve with concentric frames
Apparatus is provided for use with a heart of a subject, the apparatus including an inner stent frame defining a tubular portion, and an outer stent frame. The apparatus has a relaxed expanded state in which an outer-stent-frame relaxed expanded diameter defined by the outer slept frame is smaller than an inner-stent-frame expanded diameter defined by the tubular portion. Together, the inner stent frame and the outer stent frame define a frame assembly in which outer-frame coupling elements are fixed to inner-frame coupling elements. The frame assembly is expandable into an expanded state in which the tubular portion defines an inner-stent-frame constrained expanded diameter that is smaller than the inner-stent-frame relaxed expanded diameter. The frame assembly includes prosthetic leaflets secured to, and disposed within, the tubular portion, and has a compressed state in which the frame assembly is transluminally advanceable to the heart. Other embodiments are also described.
1. Apparatus for use with a heart of a subject, the apparatus comprising an implant, the implant comprising:
an inner stent frame that:
defines a tubular portion and a plurality of inner-frame coupling elements, and
has a relaxed expanded state in which the tubular portion defines an inner-stent-frame relaxed expanded diameter;
a plurality of prosthetic leaflets, each prosthetic leaflet:
secured to, and disposed within, the tubular portion, and
defining a commissural portion;
an outer stent frame, that:
defines a ring and a plurality of outer-frame coupling elements, and
has a relaxed expanded state in which the ring defines an outer-stent-frame relaxed expanded diameter that is smaller than the inner-stent-frame expanded diameter;
a plurality of stitches, the stitches disposed at respective commissures defined by the implant; and
a fabric connector, the fabric connector shaped to define (i) a panel having a first side and a second side, (ii) one or more leaflet-engaging tabs to which the commissural portions of the prosthetic leaflets are stitched, the tabs protruding from the first side of the panel, and (iii) a plurality of flaps, wrapped around elements of the inner stent frame and elements of the outer stent frame, and secured thus by the stitches;
wherein:
the plurality of stitches secures the commissural portions of the two leaflets to the inner stent frame and the outer stent frame by being attached to the fabric connector; and
the inner stent frame and the outer stent frame, together define at least part of a frame assembly in which:
the outer-frame coupling elements are fixed to the inner-frame coupling elements,
the ring circumscribes the tubular portion, and
the frame assembly:
has a compressed state in which the frame assembly is transluminally advanceable to the heart, and
is expandable into an expanded state in which the tubular portion defines an inner-stent-frame constrained expanded diameter that is smaller than the inner-stent-frame relaxed expanded diameter.
2. The apparatus according to claim 1 , wherein the outer frame is coupled to the inner frame such that:
in the compressed state of the frame assembly, the outer frame is in circumferential contact with the tubular portion, and
throughout expansion of the frame assembly into its expanded state, circumferential contact is maintained between the outer frame and the tubular portion.
3. The apparatus according to claim 1 , wherein the outer-frame coupling elements are welded to the inner-frame coupling elements.
4. The apparatus according to claim 1 , wherein, in the relaxed expanded state, the tubular portion is barrel-shaped.