Patent Description:
Some applications of the present invention relate in general to valve replacement. More specifically, some applications of the present invention relate to prosthetic valves for replacement of a cardiac valve.

Ischemic heart disease causes regurgitation of a heart valve by the combination of ischemic dysfunction of the papillary muscles, and the dilatation of the ventricle that is present in ischemic heart disease, with the subsequent displacement of the papillary muscles and the dilatation of the valve annulus.

Dilation of the annulus of the valve prevents the valve leaflets from fully coapting when the valve is closed. Regurgitation of blood from the ventricle into the atrium results in increased total stroke volume and decreased cardiac output, and ultimate weakening of the ventricle secondary to a volume overload and a pressure overload of the atrium.

<CIT> discloses an apparatus with sheets of material forming a pouch.

For some applications, an implant is provided having a valve body that defines a lumen, an upstream support portion, and a plurality of legs. The implant is percutaneously deliverable to a native heart valve in a compressed state, and is expandable at the native valve. The implant comprises an inner frame and an outer frame. Typically, the upstream support portion is at least partly defined by the inner frame, and the legs are at least partly defined by the outer frame. The implant is secured at the native valve by sandwiching tissue of the native valve between the upstream support portion and the legs. For some applications, a flexible pouch extends radially outward from the valve body. For some such applications, the arms and the legs narrow the pouch therebetween to form a narrowed portion of the pouch, thereby dividing an interior space of the pouch into (a) an inner portion, radially inward from the narrowed portion, and in fluid communication with the lumen, and (b) an outer portion, radially outward from the narrowed portion, and in fluid communication with the inner portion via the narrowed portion.

There is therefore provided an apparatus, including:.

In an application, at the narrowed portion, the legs extend in an upstream direction past the arms.

In an application, the arms are disposed inside the pouch.

In an application, the arms and the legs are arranged such that, at the narrowed portion, the arms and the legs alternate circumferentially.

In an application, the inner portion of the interior space is in fluid communication with the lumen via a plurality of discrete windows defined by the apparatus.

In an application, the apparatus further includes a belt wrapped around the frame assembly downstream of the windows, circumscribing the lumen, each of the windows being bounded, at a downstream edge of the window, by the belt.

In an application, the leaflets are arranged to form a plurality of commissures therebetween, and are attached to the frame assembly at the commissures, and the belt is disposed over the commissures.

In an application, at the narrowed portion, each of the legs pushes the downstream surface into contact with the upstream surface.

In an application, at the narrowed portion, each of the legs forms a respective bulge in the upstream surface by pressing the downstream surface against the upstream surface.

In an application, the pouch is stitched to the arms.

In an application, at the narrowed portion, the pouch is stitched to the arms but not to the legs.

In an application, the frame assembly includes (i) a valve frame that defines the valve body and the plurality of upstream arms, and (ii) an outer frame that circumscribes the valve frame, and defines the plurality of downstream legs.

In an application, an upstream portion of the pouch is attached to the valve frame, and a downstream portion of the pouch is attached to the outer frame.

In an application, the apparatus further includes at least one coagulation component, disposed within the outer portion of the interior space, and configured to promote blood coagulation within the outer portion of the interior space.

In an application, the coagulation component is annular, and, within the outer portion of the interior space, circumscribes the longitudinal axis.

There is further provided, in accordance with the present invention, apparatus, including:.

In an application, each of the legs forms a respective bulge in the first sheet by pressing the second sheet against the first sheet.

In an application, the legs extend in an upstream direction past the arms.

In an application, the plurality of legs forms a narrowed portion of the pouch by pressing the second sheet into contact with the first sheet, the narrowed portion of the pouch circumscribing the valve body.

In an application, at the narrowed portion, the second sheet is not stitched to the legs.

In an application, the narrowed portion of the pouch shapes the pouch to define:.

In an application, the interior space is in fluid communication with the lumen via a plurality of discrete windows defined by the apparatus.

Reference is made to <FIG> and <FIG>, which are schematic illustrations of an implant <NUM> and a frame assembly <NUM> of the implant, in accordance with some applications of the invention. Implant <NUM> serves as a prosthetic valve for use at a native heart valve of a subject - typically the mitral valve. Implant <NUM> has a compressed state for minimally-invasive (typically transluminal, e.g., transfemoral) delivery, and an expanded state into which the implant is transitioned at the native heart valve, and in which the implant provides prosthetic valve functionality. Implant <NUM> comprises frame assembly <NUM>, flexible sheeting <NUM>, and a valve member, such as prosthetic leaflets <NUM>.

<FIG> show implant <NUM> and frame assembly <NUM> in the expanded state. For clarity, <FIG> show frame assembly <NUM> alone. <FIG> shows an isometric exploded view of frame assembly <NUM>, and <FIG> shows a side exploded view of the frame assembly. <FIG> are side- and top-views, respectively, of frame assembly <NUM>, assembled. <FIG> is a perspective view of implant <NUM>, including sheeting <NUM> and leaflets <NUM>.

Implant <NUM> has an upstream end <NUM>, a downstream end <NUM>, and defines a central longitudinal axis ax1 therebetween. Frame assembly <NUM> comprises a valve frame <NUM> that comprises a valve body (which is a generally tubular portion) <NUM> that has an upstream end <NUM> and a downstream end <NUM>, and is shaped to define a lumen <NUM> through the valve body from its upstream end to its downstream end. Valve body <NUM> circumscribes axis ax1, and thereby defines lumen <NUM> along the axis. Throughout this application, including the specification and the claims, unless stated otherwise, "upstream" and "downstream," e.g., with respect to the ends of implant <NUM>, are defined with respect to the longitudinal axis of implant <NUM>, by the orientation and functioning of leaflets <NUM>, which facilitate one-way upstream-to-downstream fluid flow through lumen <NUM>.

Valve frame <NUM> further comprises a plurality of arms <NUM>, each of which, in the expanded state, extends radially outward from valve body <NUM>. In this context, the term "extends radially outward" is not limited to extending in a straight line that is orthogonal to axis ax1, but rather, and as shown for arms <NUM>, includes extending away from axis ax1 while curving in an upstream and/or downstream direction. Typically, and as shown, each arm <NUM> extends from valve body <NUM> in an upstream direction, and curves radially outward. That is, the portion of arm <NUM> closest to valve body <NUM> extends primarily upstream away from the valve body (e.g., extending radially outward only a little, extending not at all radially outward, or even extending radially inward a little), and the arm then curves to extend radially outward. The curvature of arms <NUM> is described in more detail hereinbelow.

Valve body <NUM> is defined by a repeating pattern of cells that extends around central longitudinal axis ax1. In the expanded state of each tubular portion, these cells are typically narrower at their upstream and downstream extremities than midway between these extremities. For example, and as shown, the cells may be roughly diamond or astroid in shape. Typically, and as shown, valve body <NUM> is defined by two stacked, tessellated rows of cells - an upstream row 29a of first-row cells, and a downstream row 29b of second-row cells. Frame <NUM> is typically made by cutting (e.g., laser-cutting) its basic (i.e., raw) structure from a tube of, for example, Nitinol (followed by re-shaping and heat treating to form its shape-set structure). Although valve body <NUM> is therefore typically monolithic, because the resulting cellular structure of valve body <NUM> resembles an open lattice, it may be useful to describe it as defining a plurality of joists <NUM> that connect at nodes <NUM> to form the cellular structure.

Typically, and as shown, each arm <NUM> is attached to and extends from a site <NUM> that is at the connection between two adjacent cells of upstream row 29a. That is, site <NUM> is a connection node between first-row cells. The tessellation between rows 29a and 29b is such that site <NUM> may alternatively be described as the upstream extremity of cells of downstream row 29b. That is, the upstream extremity of each second-row cell is coincident with a respective connection node between first-row cells. Site <NUM> is therefore a node <NUM> that connects four joists <NUM>. Upstream end <NUM> of valve body <NUM> may be described as defining alternating peaks and troughs, and sites <NUM> are downstream of the peaks (e.g., at the troughs).

It is hypothesized by the inventors that connecting arm <NUM> to valve body <NUM> at site <NUM> (instead of at upstream end <NUM>) maintains the length of the lumen of the tubular portion, but also advantageously reduces the distance that the tubular portion extends into the ventricle of the subject, and thereby reduces a likelihood of inhibiting blood flow out of the ventricle through the left ventricular outflow tract. It is further hypothesized by the inventors that because each site <NUM> is a node <NUM> that connects four joists (whereas each node <NUM> that is at upstream end <NUM> connects only two joists), sites <NUM> are more rigid, and therefore connecting arms <NUM> to valve body <NUM> at sites <NUM> provides greater rigidity to each arm.

Sheeting <NUM> may comprise one or more individual sheets, which may or may not be connected to each other. The individual sheets may comprise the same or different materials. Typically, sheeting <NUM> comprises a fabric, e.g., comprising a polyester, such as polyethylene terephthalate. Arms <NUM> are typically covered with sheeting <NUM>. Typically, and as shown in <FIG>, an annular sheet <NUM> of sheeting <NUM> is disposed over arms <NUM>, extending between the arms, e.g., so as to reduce a likelihood of paravalvular leakage. For some such applications, excess sheeting <NUM> is provided between arms <NUM>, so as to facilitate movement of arms <NUM> independently of each other. Annular sheet <NUM> typically covers the upstream side of arms <NUM>, but may alternatively or additionally cover the downstream side of the arms.

Alternatively, each arm <NUM> may be individually covered in a sleeve of sheeting <NUM>, thereby facilitating independent movement of the arms.

Arms <NUM>, and typically the sheeting that covers the arms, define an upstream support portion <NUM> of implant <NUM>.

Other surfaces of frame assembly <NUM> may also be covered with sheeting <NUM>. Typically, sheeting <NUM> covers at least part of valve body <NUM>, e.g., defining a liner <NUM> that lines an inner surface of the valve body, and thereby defining lumen <NUM>.

Support <NUM> has an upstream surface, and a downstream surface. Each arm <NUM> is typically curved such that a downstream surface of support <NUM> defines an annular concave region <NUM>, and an annular convex region <NUM> radially outward from the concave region. That is, in region <NUM> the downstream surface of support <NUM> (e.g., the downstream surface of each arm <NUM> thereof) is concave, and in region <NUM> the downstream surface of the support is convex.

Concave region <NUM> extends radially between a concave-region inner radius r1 and a concave-region outer radius r2. Convex region <NUM> extends radially between a convex-region inner radius r3 and a concave-region outer radius r4. It is to be noted that in this context (including the specification and the claims), the term "radius" means a radial distance from axis ax1.

For some applications, and as shown, each arm <NUM> has a serpentine shape, such that there is no discernable gap between concave region <NUM> and convex region <NUM>. For such applications, each arm <NUM> has an inflection point where region <NUM> transitions into region <NUM>. For such applications, radius r2 and radius r3 are coincident, and collectively define an inflection radius at which the inflection point of each arm lies.

For some applications, radius r1 is the radius of tubular portion <NUM>. For some applications, there is a discernable gap between regions <NUM> and <NUM>. For example, each arm may be curved in regions <NUM> and <NUM>, but have a straight portion between these regions.

Although regions <NUM> and <NUM> may be locally defined with respect to one or more particular arms <NUM>, these regions typically completely circumscribe axis ax1.

Frame assembly <NUM> further comprises a plurality of legs <NUM>, each of which, in the expanded state, extends radially outward and in an upstream direction from a respective leg-base <NUM> to a respective leg-tip <NUM>. Each leg <NUM> defines a tissue-engaging flange <NUM>, which is typically the most radially outward part of the leg, and includes leg-tip <NUM>. Typically, legs <NUM> are defined by an outer frame (or "leg frame") <NUM> that circumscribes and is coupled to valve frame <NUM>.

Frames <NUM> and <NUM> define respective coupling elements <NUM> and <NUM>, which are fixed with respect to each other at coupling points <NUM>. For some applications, frames <NUM> and <NUM> are attached to each other only at coupling points <NUM>. Although frames <NUM> and <NUM> are attached to each other at coupling points <NUM>, radial forces may provide further coupling between the frames, e.g., frame <NUM> pressing radially outward against frame <NUM>.

Typically, coupling points <NUM> are circumferentially aligned with legs <NUM> (and flanges <NUM> thereof), but circumferentially offset with respect to arms <NUM>. That is, the coupling points are typically at the same rotational position around axis ax1 as the legs, but are rotationally staggered with respect to the rotational position of the arms.

Coupling points <NUM> are typically disposed circumferentially around frame assembly <NUM> on a transverse plane that is orthogonal to axis ax1. That is, coupling points <NUM> are typically all disposed at the same longitudinal position along axis ax1. Typically, coupling points <NUM> are disposed longitudinally between upstream end <NUM> and downstream end <NUM> of frame assembly <NUM>, but not at either of these ends. Further typically, coupling points <NUM> are disposed longitudinally between upstream end <NUM> and downstream end <NUM> of tubular portion <NUM>, but not at either of these ends. As shown, tubular portion <NUM> is typically barrel-shaped - i.e., slightly wider in the middle than at either end. For some applications, and as shown, coupling points <NUM> are disposed slightly downstream of the widest part of tubular portion <NUM>. For example, coupling points <NUM> may be <NUM>-<NUM> downstream of the widest part of tubular portion <NUM>. Alternatively or additionally, the longitudinal distance between the widest part of tubular portion <NUM> and coupling points <NUM> may be <NUM>-<NUM> percent (e.g., <NUM>-<NUM> percent) of the longitudinal distance between the widest part of the tubular portion and downstream end <NUM>.

Coupling elements <NUM> are typically defined by (or at least directly attached to) legs <NUM>. Therefore legs <NUM> are fixedly attached to frame <NUM> at coupling points <NUM>. Despite the fixed attachment of legs <NUM> to frame <NUM>, frame <NUM> comprises a plurality of struts <NUM> that extend between, and connect, adjacent legs. Struts <NUM> are typically arranged in one or more rings <NUM>, e.g., a first (e.g., upstream) ring <NUM> and a second (e.g., downstream) ring <NUM>. For some applications, and as shown, frame <NUM> comprises exactly two rings <NUM>. Each ring is defined by a pattern of alternating peaks <NUM> and troughs <NUM>, the peaks being further upstream than the troughs. Each ring is typically coupled to legs <NUM> at troughs <NUM> - i.e., such that peaks <NUM> are disposed circumferentially between the legs. Peaks <NUM> are therefore typically circumferentially aligned with arms <NUM>. That is, peaks <NUM> are typically at the same rotational position around axis ax1 as arms <NUM>.

The elongate element of frame <NUM> that defines leg <NUM> continues in a downstream direction past ring <NUM> and coupling element <NUM>, and couples ring <NUM> to ring <NUM>. However, throughout this patent application, leg <NUM> itself is defined as the free portion of this elongate element that extends from ring <NUM>. Leg-base <NUM> may be defined as the region of leg <NUM> that is coupled to the remainder of frame <NUM> (e.g., to ring <NUM>). Because each leg <NUM> extends in a generally upstream direction, leg-base <NUM> may also be defined as the most downstream region of leg <NUM>.

In the expanded state, the leg-tip <NUM> of each leg is typically disposed radially between radius r3 and radius r4. That is, the leg-tip <NUM> of each leg is aligned with convex region <NUM>.

Frame <NUM> is typically cut from a single tube, e.g., of Nitinol. Therefore, the radial thickness of the frame is typically consistent throughout - e.g., it is the wall thickness of the tube from which it was cut. However, the circumferential width of components of frame <NUM> (i.e., the width of the component measured around the circumference of the frame) may differ. For example, for some applications, a circumferential thickness W2 of legs <NUM> may be at least three times greater than a circumferential thickness W1 of struts <NUM>. Greater circumferential thickness typically provides the component with greater rigidity.

Valve frame <NUM> and outer frame <NUM> are typically each cut from respective metallic tubes, e.g., of Nitinol. This is typically the case for each of the implants described herein. More specifically, for each of the implants described herein:.

Prosthetic leaflets <NUM> are disposed within lumen <NUM>, and are configured to facilitate one-way liquid flow through the lumen from upstream end <NUM> to downstream end <NUM>. Leaflets <NUM> thereby define the orientation of the upstream and downstream ends of valve body <NUM>, and of implant <NUM> in general.

Typically, implant <NUM> is biased (e.g., shape-set) to assume its expanded state. For example, frames <NUM> and <NUM> may be constructed from a shape-memory metal such as Nitinol or a shape-memory polymer. Transitioning of implant <NUM> between the respective states is typically controlled by delivery apparatus, such as by constraining the implant in a compressed state within a capsule and/or against a control rod, and selectively releasing portions of the implant to allow them to expand.

<FIG> shows implant <NUM> in its compressed state, for delivery to the heart of the subject, e.g., within a capsule <NUM> or delivery tube. Capsule <NUM> may be a capsule or a catheter. For clarity, only frame assembly <NUM> of implant <NUM> is shown. In the compressed state, arms <NUM> define a ball <NUM> at an end of valve body <NUM>. It is to be noted that in this context, the term "ball" (including the specification and the claims) means a substantially bulbous element. The ball may be substantially spherical, spheroid, ovoid, or another bulbous shape.

In the compressed state, frame assembly <NUM> defines a waist <NUM> (i.e., is waisted) at a longitudinal site between the valve body and the ball. For some applications, and as shown, waist <NUM> is longitudinally upstream of frame <NUM>, and is therefore primarily defined by valve frame <NUM>. However, for some such applications, the downstream limit of the waist may be defined by the upstream limit of frame <NUM> (e.g., flanges <NUM> thereof).

It is to be noted that, typically, the bulbous shape of ball <NUM> is interrupted at waist <NUM>, i.e., where the frame transitions from the ball to the waist. For some applications, and as shown, valve frame <NUM> is monolithic (e.g., cut from a single metal tube), and defines both valve body <NUM> and arms <NUM>. For some applications, and as shown, in the compressed state, the overall shape of valve frame <NUM> resembles that of an air rifle pellet or a shuttlecock (e.g., see the cross-section in <FIG>). For some applications, a longitudinal cross-section of frame <NUM> has an overall shape that resembles a keyhole.

For some applications, at waist <NUM>, frame <NUM> (and typically frame assembly <NUM> overall) has a transverse diameter d10 that is less than <NUM> (e.g., <NUM>-<NUM>). For some applications, ball <NUM> has a greatest transverse diameter d11 of <NUM>-<NUM> (e.g., <NUM>-<NUM>). For some applications, transverse diameter d10 is less than <NUM> percent (e.g., less than <NUM> percent, such as <NUM>-<NUM> percent) of transverse diameter d11.

Due to waist <NUM>, while implant <NUM> is in its compressed state and disposed within capsule <NUM>, the implant and capsule define a toroidal gap <NUM> therebetween. Toroidal gap <NUM> circumscribes longitudinal axis ax1 of the implant around waist <NUM>. Therefore, valve body <NUM> extends in a first longitudinal direction (i.e., in a generally downstream direction) away from gap <NUM>, and arms <NUM> extend in a second longitudinal direction (i.e., in a generally upstream direction) away from the gap. For applications in which implant <NUM> is delivered to the native valve transfemorally, valve body <NUM> is closer to the open end of capsule <NUM> than is gap <NUM>, and arms <NUM> (e.g., ball <NUM>) are further from the open end of capsule <NUM> than is gap <NUM>. For some applications, and as shown, a downstream limit of gap <NUM> is defined by the tips of flanges <NUM>. For some applications, and as shown, an upstream limit of gap <NUM> is defined by the downstream side of arms <NUM>.

It is to be noted that, typically, frame <NUM> is disposed only downstream of toroidal gap <NUM>, but the frame <NUM> is disposed both upstream and downstream of the toroidal gap.

Reference is again made to <FIG>. For some applications, implant <NUM> comprises a polytetrafluoroethylene (e.g., Teflon) ring <NUM> attached to downstream end <NUM>. Ring <NUM> circumscribes lumen <NUM> at downstream end <NUM> of valve body <NUM>, and typically at downstream end <NUM> of implant <NUM>. Therefore ring <NUM> serves as a downstream lip of lumen <NUM>. Typically, ring <NUM> is attached (e.g., stitched) to both frame <NUM> and frame <NUM>. For example, ring <NUM> may be attached to frame <NUM> at troughs <NUM>. For some applications, ring <NUM> is stitched to downstream end <NUM> of valve body <NUM> by stiches <NUM> that wrap around the ring (i.e., through the opening of the ring and around the outside of the ring) but do not pierce the ring (i.e., the material of the ring).

Typically, ring <NUM> covers downstream end <NUM> of the implant (e.g., covers the frames at the downstream end). It is hypothesized by the inventors that ring <NUM> advantageously protects tissue (e.g., native leaflets and/or chordae tendineae) from becoming damaged by downstream end <NUM> of implant <NUM>. There is therefore provided an apparatus comprising:.

Reference is made to <FIG>, which are schematic illustrations showing the implantation of implant <NUM> at a native valve <NUM> of a heart <NUM> of a subject.

Valve <NUM> is shown as a mitral valve of the subject, disposed between a left atrium <NUM> and a left ventricle <NUM> of the subject. However, implant <NUM> may be implanted at another heart valve of the subject, mutatis mutandis. Similarly, although <FIG> show implant <NUM> being delivered transseptally via a sheath <NUM>, the implant may alternatively be delivered by any other suitable route, such as transatrially, or transapically.

Implant <NUM> is delivered, in its compressed state, to native valve <NUM> using a delivery tool <NUM> that is operable from outside the subject (<FIG>). Tool <NUM> typically comprises an extracorporeal controller <NUM> (e.g., comprising a handle) at a proximal end of the tool, and a shaft <NUM> extending from the controller to a distal portion of the tool. At the distal portion of tool <NUM>, the tool typically comprises a capsule <NUM> comprising one or more capsule portions <NUM>, <NUM> (described below), and a mount <NUM>. Mount <NUM> is coupled (typically fixed) to shaft <NUM>. Controller <NUM> is operable to control deployment of implant <NUM> by transitioning the tool between a delivery state (<FIG>), an intermediate state (<FIG>), and an open state (<FIG>). Typically, implant <NUM> is delivered within capsule <NUM> of tool <NUM> in its delivery state, the capsule retaining the implant in the compressed state. Implant <NUM> typically comprises one or more appendages <NUM> at downstream end <NUM>, each appendage typically shaped to define a catch or other bulbous element at the end of the appendage, and to engage mount <NUM>, e.g., by becoming disposed within notches in the mount. Appendages <NUM> are typically defined by valve frame <NUM>, but may alternatively be defined by outer frame <NUM>. Capsule <NUM> retains appendages <NUM> engaged with mount <NUM> by retaining implant <NUM> (especially downstream end <NUM> thereof) in its compressed state. A transseptal approach, such as a transfemoral approach, is shown. At this stage, frame assembly <NUM> of implant <NUM> is as shown in <FIG>.

Subsequently, flanges <NUM> are deployed - i.e., are allowed to protrude radially outward, e.g., by releasing them from capsule <NUM> (<FIG>). For example, and as shown, capsule <NUM> may comprise a distal capsule-portion <NUM> and a proximal capsule-portion <NUM>, and the distal capsule-portion may be moved distally with respect to implant <NUM>, so as to expose flanges <NUM> while continuing to restrain upstream end <NUM> and downstream end <NUM> of implant <NUM>. In <FIG>, upstream support portion <NUM> (e.g., arms <NUM>) is disposed within capsule-portion <NUM>, and downstream end <NUM> of tubular portion <NUM> is disposed within capsule-portion <NUM>.

Typically, and as shown in <FIG>, tool <NUM> is positioned such that when flanges <NUM> are deployed, they are deployed within atrium <NUM> and/or between leaflets <NUM> of the subject. Subsequently, the tool is moved downstream (distally, for a transseptal approach) until the leaflets are observed to coapt upstream of flanges <NUM> (<FIG>). It is hypothesized by the inventors that this reduces how far into ventricle <NUM> the flanges become disposed, and therefore reduces the distance that the deployed flanges must be moved in an upstream direction in order to subsequently engage the leaflets, and therefore reduces the likelihood of inadvertently or prematurely ensnaring tissue such as chordae tendineae. This is described in more detail, mutatis mutandis, in <CIT>.

Alternatively, flanges <NUM> may be initially deployed within ventricle <NUM>.

Subsequently, implant <NUM> is moved upstream, such that flanges <NUM> engage leaflets <NUM> of valve <NUM> (<FIG>).

Subsequently, delivery tool <NUM> is transitioned into its intermediate state, thereby allowing implant <NUM> to assume a partially-expanded state in which upstream support portion <NUM> is expanded, e.g., by releasing the upstream support portion from capsule <NUM> (<FIG>). For example, and as shown, proximal capsule-portion <NUM> may be moved proximally with respect to mount <NUM> and/or implant <NUM>, so as to expose upstream support portion <NUM> (e.g., arms <NUM>). Typically, in this state, upstream support portion <NUM> has expanded to have a diameter that is at least <NUM> percent (e.g., at least <NUM> percent, e.g., at least <NUM> percent) of its diameter in the expanded state of implant <NUM> (e.g., the diameter after implantation is complete), while downstream end <NUM> of the implant remains compressed. For some applications, in the partially-expanded state, upstream support portion <NUM> has expanded to its fully-expanded diameter. That is, downstream end <NUM> of tubular portion <NUM> remaining disposed within capsule-portion <NUM> typically does not inhibit, by more than <NUM> percent, if at all, the expansion of upstream support portion <NUM>. However, in the partially-expanded state of implant <NUM>, legs <NUM> are partially inhibited from expanding, such that each leg-tip <NUM> is radially aligned with concave region <NUM>. That is, each leg-tip <NUM> is disposed radially between concave-region inner radius r1 and concave-region outer radius r2.

In the intermediate state, leaflets <NUM> of native valve <NUM> are sandwiched between upstream support portion <NUM> (e.g., annular sheet <NUM> thereof) and legs <NUM> (e.g., flanges <NUM> thereof). It is to be noted that appendages <NUM> remain engaged with mount <NUM>.

Subsequently, delivery tool <NUM> is transitioned into its open state, thereby allowing implant <NUM> to expand toward its expanded state (i.e., such that tubular portion <NUM> widens to its fully-expanded state) (<FIG>). For example, capsule-portion <NUM> may be moved distally with respect to mount <NUM> and/or implant <NUM>. The resulting expansion of downstream end <NUM> of implant <NUM> disengages appendages <NUM>, and thereby implant <NUM> as a whole, from mount <NUM>. Appendages <NUM> are not visible in <FIG> (or <FIG>) because they are obscured by ring <NUM>.

In the expanded state of implant <NUM>, each leg-tip <NUM> is radially aligned with convex region <NUM>. That is, each leg-tip <NUM> is disposed radially between convex-region inner radius r3 and convex-region outer radius r4. This is also illustrated in <FIG>.

Tool <NUM> (e.g., capsule-portion <NUM> thereof) may then be withdrawn via lumen <NUM> of implant <NUM>, and removed from the body of the subject.

Reference is made to <FIG>, and <FIG>, which are schematic illustrations of implants.

<FIG> shows an implant <NUM>. <FIG> shows an implant <NUM>, <FIG> shows a frame assembly <NUM> of implant <NUM> after shape-setting, and <FIG> shows a valve frame <NUM> of frame assembly <NUM> prior to shape-setting (i.e., the shape-set valve-frame structure).

Implants <NUM> and <NUM> are typically the same as implant <NUM>, described hereinabove, except where noted. Sheeting <NUM> forms annular sheet <NUM> that is disposed over and typically stitched to arms <NUM>. Implant <NUM> thereby comprises valve body <NUM> (e.g., as described hereinabove), and an upstream support portion <NUM> that itself comprises arms <NUM> and annular sheet <NUM>. Similarly, implant <NUM> comprises valve body <NUM> and an upstream support portion <NUM> that itself comprises arms <NUM> and annular sheet <NUM>.

Implants <NUM> and <NUM> each further comprises a respective plurality of elongate projections <NUM> or <NUM>. Whereas arms <NUM> are covered by sheeting <NUM>, the projections extend in an upstream direction through sheeting <NUM>. For some applications, and as shown for projections <NUM>, the projections extend through annular sheet <NUM>. For some applications, and as shown for projections <NUM>, the projections extend between annular sheet <NUM>, and a portion of sheeting <NUM> that lines valve body <NUM> (e.g., at a seam where these two portions of sheeting <NUM> are joined). The projections and arms <NUM> are both configured to be positioned in atrium <NUM> of the heart. For some applications, and as shown for projections <NUM>, the projections extend through annular sheet <NUM>.

It is to be noted that projection <NUM> and <NUM> are distinct from appendages <NUM>, which are disposed at the other end of the valve body.

Each projection terminates in a nub <NUM> or <NUM> that facilitates snaring of the projection using a transcatheter snare, lasso, or similar tool. It is to be understood that the shapes shown for the nubs are merely examples, and that the scope of the disclosure includes any suitably shaped nub. It is hypothesized by the inventors that the projections facilitate repositioning and/or retrieval of the implant during and/or after implantation, using a snare, lasso, or similar tool. The projections are typically positioned and/or shaped such that nubs <NUM> or <NUM> are not in contact with annular sheet <NUM> or atrial tissue (e.g., are disposed at least <NUM> away (e.g., <NUM>-<NUM> away) from annular sheet <NUM> or atrial tissue). For some applications, and as shown for projections <NUM> of implant <NUM>, the projections curve outwards and then inwards toward the central longitudinal axis of the implant (i.e., are shaped to be concave toward the axis). For some applications, and as shown for projections <NUM> of implant <NUM>, the projections do not extend radially outward from the valve body. Projections <NUM> typically extend axially in an upstream direction away from the valve body (i.e., generally parallel to axis ax1, i.e., within <NUM> degrees of axis ax1).

Regarding implant <NUM> (<FIG>), projections <NUM> extend from sites <NUM> in a similar way to arms <NUM>. Projections <NUM> may be structurally similar to arms <NUM>, and may even be identically cut when frame <NUM> is initially cut from the original metal tube (i.e., in the raw valve-frame structure). However, projections <NUM> have a different curvature to arms <NUM> (e.g., they may be bent differently post-cutting), and are curved such that they extend through annular sheet <NUM>. Whereas at least some of arms <NUM> typically reach and press against the atrial wall, projections <NUM> are typically shaped such that nubs <NUM> are not in contact with the atrial wall. Typically, each projection <NUM> replaces an arm <NUM>, such that the cumulative sum of arms and projections is twelve. <FIG> shows an embodiment comprising six arms <NUM> and six projections <NUM>, but the scope of the disclosure includes other ratios, such as nine arms <NUM> and three projections <NUM>.

<FIG> shows implant <NUM>, comprising a frame assembly <NUM>, leaflets <NUM>, and sheeting <NUM>. <FIG> shows frame assembly <NUM> alone, the frame assembly comprising (i) a valve frame <NUM> that defines valve body <NUM>, and (ii) an outer frame <NUM>. <FIG> shows the basic structure of valve frame <NUM>, as it is initially cut from a tube (typically a metallic tube, such as a Nitinol tube), e.g., before the frame is shape-set into the shape shown in <FIG>. Although this basic structure is tubular, <FIG> depicts the structure two-dimensionally, as though the cut-out structure were cut longitudinally, and unrolled to become flat.

Except where noted, frame assembly <NUM>, valve frame <NUM>, and outer frame <NUM> are typically identical to frame assembly <NUM>, valve frame <NUM>, and outer frame <NUM>, mutatis mutandis. For some applications, implant <NUM> is identical to implant <NUM> except for projections <NUM>.

In contrast to projections <NUM> of implant <NUM>, each projection <NUM> of implant <NUM> extends from a respective site <NUM> that is at the upstream extremity (i.e., peak) of a respective first-row cell of upstream row 29a of valve body <NUM> (i.e., from upstream end <NUM> of the valve body). Projections <NUM> thereby alternate with, rather than replace, arms <NUM>. Therefore, it is possible for implant <NUM> to comprise projections <NUM> in addition to twelve arms <NUM>. Implant <NUM> may comprise an equal number of projections <NUM> and arms <NUM>, but typically, the implant comprises fewer projections than arms. For example, implant <NUM> may comprise half as many, or fewer, projections <NUM> than arms <NUM> - e.g., a third as many, or a quarter as many projections as arms. Projections <NUM> and arms <NUM> are typically evenly distributed circumferentially, and therefore typically at least two arms (e.g., at least three arms, such as at least four arms) are disposed circumferentially between each projection and each of its circumferentially-neighboring projections. <FIG> show implant <NUM> comprising three projections <NUM> and twelve arms <NUM>, with four arms disposed circumferentially between each projection and each of its circumferentially-neighboring projections. <FIG>, described hereinbelow, show an implant in which three arms are disposed circumferentially between each projection and each of its circumferentially-neighboring projections.

Each projection <NUM> has a projection-length d13, measured from the upstream extremity of the respective first-row cell (i.e., from site <NUM>). Each of the arms has an arm-length d14, measured from the upstream extremity of the respective second-row cell (i.e., site <NUM>). Arm-length d14 is greater than projection-length d13 (e.g., <NUM>-<NUM> times greater, e.g., <NUM>-<NUM> times greater, such as <NUM>-<NUM> times greater). For some applications, arm-length d14 is <NUM>-<NUM>, such as <NUM>-<NUM> (e.g., <NUM>-<NUM>, <NUM>-<NUM>, or <NUM>-<NUM>). For some applications, projection-length d13 is <NUM>-<NUM> (e.g., <NUM>-<NUM>, e.g., <NUM>-<NUM>, such as about <NUM>).

Typically, each arm <NUM> (i) has a narrow portion 46a that is attached to, and extends from, the upstream extremity of the respective second-row cell, and (ii) at a widening zone 46b, widens into a wide portion 46c that extends from the narrow portion, and is wider than the narrow portion. Narrow portion 46a has a narrow-portion length d20 that is typically at least <NUM> percent of arm-length d14 (e.g., at least <NUM> percent, such as <NUM>-<NUM> percent, such as <NUM>-<NUM> percent). Wide portion 46c has a wide-portion length that is at least <NUM> percent of arm-length d14 (e.g., at least <NUM> percent, such as <NUM>-<NUM> percent, such as <NUM>-<NUM> percent).

Wide portion 46c has a width d15 that is typically <NUM>-<NUM> times greater (e.g., <NUM>-<NUM> times greater, such as <NUM>-<NUM> times greater) than a width d16 of narrow portion 46a. For some applications width d15 is <NUM>-<NUM> (e.g., <NUM>-<NUM>, such as <NUM>). Width d16 is typically <NUM>-<NUM> (e.g., <NUM>-<NUM>, such as <NUM>). It is to be noted that, although individual parts of arm <NUM> within portion 46c may be narrower than within portion 46a, these individual parts form a back-and-forth pattern that results in wide portion 46c being, overall, wider than narrow portion 46a. Typically, wide portion 46c is more flexible, in at least one plane, than narrow portion 46a. Therefore, wide portion 46c is also a flexible portion of arm <NUM>.

Each projection <NUM> has a width d17 that is typically <NUM>-<NUM> (e.g., <NUM>-<NUM>, such as <NUM>). Each nub has a nub-width d18 that is typically <NUM>-<NUM> (e.g., <NUM>-<NUM>, such as <NUM>), and a nub-length d19 that is typically <NUM>-<NUM> (e.g., <NUM>-<NUM>, such as <NUM>). Wide portion 46c is typically at least <NUM> times (e.g., at least <NUM> times) longer than nub-length d19.

As described hereinabove, the valve frame is typically monolithic, cut from a single tube. Typically, and as shown in <FIG>, while valve frame <NUM> is in its raw valve-frame structure (e.g., described hereinabove with reference to <FIG>, mutatis mutandis), nubs <NUM> are disposed between arms <NUM>. As shown in <FIG>, arms <NUM> and projections <NUM> may be dimensioned such that, while valve frame <NUM> is in its raw valve-frame structure, nubs <NUM> are disposed between narrow portions 46a of arms <NUM>. That is, nubs <NUM> may be disposed axially closer than wide portion 46c to valve body <NUM>. Thereby, arms <NUM> and projections <NUM> efficiently fit adjacently to each other within a single cutout from tube of a particular diameter. Narrow-portion length d20 is typically greater than projection-length d13 (e.g., at least <NUM> times greater, such as <NUM>-<NUM> times greater).

Reference is now made to <FIG>, which shows the basic structure of a variant 230a of valve frame <NUM>.

<FIG> shows variant 230a as it is initially cut from a tube (typically a metallic tube, such as a Nitinol tube), e.g., before the frame is shape-set. <FIG> shows a two-dimensional view, as though the cut-out structure were cut longitudinally, and unrolled to become flat. Similarly to with frame <NUM> (<FIG>), nubs <NUM> of variant 230a are disposed between arms <NUM>. However, projections 246a of variant 230a are longer than projections <NUM> of frame <NUM>, and nubs 248a are therefore disposed between wide portions 46c of arms <NUM>. In order to accommodate this, in frame 230a, at least the arms <NUM> that are adjacent to nubs 248a are deflected circumferentially (which is represented two-dimensionally as being laterally deflected) compared to their positions in frame <NUM>, and are typically unevenly spaced. During subsequent shape setting, arms <NUM> are typically circumferentially displaced, e.g., such that they are evenly spaced. Variant 230a may be used in place of any other valve frame described herein, mutatis mutandis. Similarly, variant 230a may be used in combination with other technologies described herein, mutatis mutandis.

Reference is made to <FIG>, which is a schematic illustration of an outer frame 60a.

Outer frame 60a is typically identical to outer frame <NUM> except that peaks 64a of frame 60a have a larger radius of curvature than do peaks <NUM> of frame <NUM>. Outer frame 60a may be used in place of any other outer frame described herein, mutatis mutandis. Similarly, frame 60a may be used in combination with other technologies described herein, mutatis mutandis.

Reference is made to <FIG>, which is a schematic illustration of a frame assembly 22b.

Frame assembly 22b comprises a valve frame 30b and an outer frame 60b. Except where noted, frame assembly 22b, valve frame 30b, and outer frame 60b are as described for frame assembly <NUM>, valve frame <NUM>, and outer frame <NUM>, respectively.

Outer frame 60b comprises (or defines) (<NUM>) a first (e.g., upstream) ring 74b defined by a pattern of alternating first-ring peaks and first-ring troughs, (<NUM>) a second (e.g., downstream) ring 76b defined by a pattern of alternating second-ring peaks and second-ring troughs, and a plurality of legs <NUM>, each of the legs coupled to the first ring and the second ring, and extending radially outward.

Valve frame 30b comprises a tubular portion (e.g., a tubular frame) that has a cellular structure defined by a plurality of metallic elements with spaces therebetween a e.g., as described for valve frame <NUM>, mutatis mutandis.

The cellular structure of the valve frames described herein may also be viewed as defining rings of alternating peaks and troughs, the rings circumscribing the longitudinal axis of the implant. Whereas the waveform (i.e., the peak-trough waveform) of the rings of the outer frame are in phase with each other, the phase of the waveform of the rings of the valve frame typically alternate with respect to each other. That is, for the valve frame, the waveform of one ring is out of phase (e.g., is in antiphase) with that of its axially-adjacent rings. For example, and with reference to <FIG>, valve frame <NUM> defines a first (e.g., upstream) ring <NUM>, a second (e.g., middle) ring <NUM>, and a third (e.g., downstream) ring <NUM>, and ring <NUM> is in antiphase with rings <NUM> and <NUM>. Valve frame 30b similarly defines a first (e.g., upstream) ring 182b, a second (e.g., middle) ring 184b, and a third (e.g., downstream) ring 186b, and ring 184b is in antiphase with rings 182b and 184b.

Typically, and as shown for each of the implants described herein, when the frame assembly is assembled, (<NUM>) the waveform of one of outer frame rings is in-phase with the waveform of the inner frame ring with which it is axially aligned, and (<NUM>) the waveform of one of outer frame rings is out of phase (e.g., is in antiphase) with the waveform of the inner frame ring with which it is axially aligned. For example, and with reference to <FIG>, ring <NUM> is in-phase with the ring of the inner frame with which it is axially aligned (ring <NUM>), whereas ring <NUM> is in antiphase with the ring of the inner frame with which it is axially aligned (ring <NUM>). Similarly, for frame assembly 22b, ring 74b is in-phase with the ring of the inner frame with which it is axially aligned (ring 184b), whereas ring 76b is in antiphase with the ring of the inner frame with which it is axially aligned (ring 186b).

Because ring 76b is in antiphase with ring 186b, the peaks of ring 76b are not disposed directly radially outward from respective parts of frame 30b, and therefore are not in contact with frame 30b. However, despite ring 74b being in phase with ring 184b, and the peaks of ring 74b being disposed directly radially outward from respective parts of frame 30b, the peaks of ring 74b are also not in contact with frame 30b. That is, frame assembly <NUM> defines a radial gap <NUM> between frames <NUM> and <NUM> at the peaks of ring 74b. Typically, therefore, none of the peaks of the rings of frame 60b is in contact with inner frame 30b. In contrast, for frame assembly <NUM>, although the peaks of ring <NUM> are not in contact with frame <NUM>, the peaks of ring <NUM> typically are in contact with frame <NUM>.

The features of frame assembly 22b may be used in combination with other implants described herein. For example, other frame assemblies described herein may be shaped to define gap <NUM>, mutatis mutandis.

Reference is made to <FIG>, which are schematic illustrations of an inner frame 330a, and an implant 320a comprising inner frame 330a.

Inner frame 330a may be used in place of other inner frames of implants described herein, mutatis mutandis. Similarly, frame 330a may be used in combination with other technologies described herein, mutatis mutandis. Inner frame 330a comprises a valve body (which is a generally tubular portion) 332a that has an upstream end 334a and a downstream end 336a, and is shaped to define a lumen through the valve body from its upstream end to its downstream end. Valve frame 330a further comprises a plurality of arms <NUM>, each of which, in the expanded state, extends radially outward from valve body 332a.

Valve body 332a has a cellular structure defined by a plurality of joists <NUM> connected at a plurality of nodes <NUM>, the joists and nodes delimiting cells of the cellular structure. Except where noted, inner frame 330a is generally the same as inner frame <NUM> (or inner frame <NUM>), mutatis mutandis, and valve body 332a is generally the same as valve body <NUM>, mutatis mutandis. Compared to valve body <NUM>, valve body 332a comprises additional joists <NUM>, which are hypothesized by the inventors to increase strength and rigidity. In particular, the additional joists are hypothesized by the inventors to increase the resistance of the valve body to compression toward axis ax1, including resistance to circumferential compression (e.g., compression that would otherwise reduce the diameter of the valve body, but that would retain the valve body in a generally cylindrical shape) and localized compression (e.g., compression that would otherwise reduce the diameter of the valve body at only certain locations, causing the valve body to become more oval in transverse cross-section).

Referring back to <FIG>, the cellular structure of valve body <NUM> is such that its nodes <NUM> typically connect <NUM>-<NUM> of its joists. For example, a node 100a connects two joists, and a node 100b connects four joists. (In this context, neither arms <NUM> nor projections <NUM> are joists of the valve body's cellular structure, and so sites <NUM> and <NUM> are also nodes that connect <NUM>-<NUM> joists. ) In contrast, the cellular structure of valve body 332a is such that some of its nodes <NUM> are minor nodes <NUM>, and some are major nodes <NUM>. Minor nodes <NUM> connect <NUM>-<NUM> joists, whereas major nodes <NUM> connect <NUM>-<NUM> joists. Typically, and as shown, major nodes <NUM> connect <NUM> joists (again, excluding arms <NUM>, which are not joists of the valve body's cellular structure). Typically, and as shown, minor nodes <NUM> connect <NUM> joists. Therefore, for some applications, none of the nodes <NUM> of the cellular structure of valve body 332a connects <NUM> joists.

Similarly to valve body <NUM> of frame <NUM>, the cells of the cellular structure of valve body 332a comprise a first circumferential row 109a of cells, and a second circumferential row 109b of cells. That is, row 109a is a row of first-row cells, and row 109b is a row of second-row cells. Each of the cells of row 109a is connected to each of its circumferentially-adjacent first-row cells at a respective major node <NUM>. Typically, and as shown, each of the cells of row 109a is longitudinally delimited by two minor nodes <NUM> (i.e., the upstream end and the downstream end of each cell is at a respective minor node). It is to be noted that, typically, each of the cells of row 109a is not connected to another cell at these minor nodes <NUM> (i.e., the minor nodes that longitudinally delimit the first-row cell).

Each of the cells of row 109b is connected to each of its circumferentially-adjacent second-row cells at a respective major node <NUM>. Typically, and as shown, each of the cells of row 109b is longitudinally delimited by at least one major node <NUM> (e.g., is delimited by one major node at an upstream end of the cell). Typically, and as shown, each of the cells of row 109b is also longitudinally delimited by a minor node <NUM> (e.g., at a downstream end of the cell). For some applications, and as shown, each of the major nodes <NUM> at which circumferentially-adjacent first-row cells are connected is also the major node that longitudinally-delimits a respective second-row cell (e.g., at the upstream end of the second-row cell). In the example shown, that common major node <NUM> is also site <NUM>, at which arms <NUM> are attached to the valve body.

The cells of the cellular structure of valve body 332a are typically delimited by exactly four nodes <NUM>.

Frame 330a defines coupling elements <NUM>, which are fixed to coupling elements <NUM> of frame <NUM> at coupling points, as described hereinabove for frame assembly <NUM>, mutatis mutandis. For some applications, and as shown, coupling elements <NUM> are defined by respective major nodes <NUM>. Therefore, for some applications, a frame assembly comprises (i) inner frame 330a that defines valve body 332a, and (ii) an outer frame (e.g., frame <NUM>) that circumscribes the valve body, and is coupled to the inner frame by being fixed to major nodes of the valve body. For such applications, coupling elements <NUM> are typically defined by the major nodes at which circumferentially-adjacent second-row cells are connected.

For some applications, and as shown, valve body 332a is defined by exactly two stacked, tessellated rows <NUM> of cells. That is, typically, first row 109a is the most upstream row, second row 108b is the most downstream row, and these two rows are tessellated with each other. Therefore, for some applications, all the cells of the cellular structure of valve body 332a are either first-row cells or second-row cells.

Valve body 332a may be described as comprising pairs <NUM> of joists <NUM> that run generally parallel to each other. In the expanded state of the valve body (i.e., the state shown in <FIG>) the joists <NUM> of each pair <NUM> are disposed <NUM>-<NUM> (e.g., <NUM>-<NUM>, such as <NUM>-<NUM>) from each other. Although the joists <NUM> of each pair <NUM> run generally parallel to each other, they typically only share one node <NUM> in common. That shared common node is typically a major node <NUM>. That is, at a first end of each pair <NUM>, both joists <NUM> are typically connected to each other at a major node. In some cases, at a second end of each pair <NUM>, one of the joists connects to another major node <NUM>, but the other joist connects to a minor node <NUM> that is disposed a distance d12 away from the major node at the second end of the pair. In other cases, at the second end of each pair <NUM>, one of the joists connects to a first minor node, and the other joist connects to another minor node that is disposed a distance d12 away from the first minor node. Distance d12 is typically <NUM>-<NUM> (e.g., <NUM>-<NUM>, such as <NUM>-<NUM>).

For some applications, and as shown, the arrangement of joists <NUM> in pairs <NUM> results in the joists that delimit the cells of first row 109a not delimiting the cells of second row 109b. That is, for some applications, no individual joist <NUM> delimits both a first-row cell and a second-row cell.

Another aspect of valve body 332a is as follows: Major nodes <NUM> are typically arranged in major-node rows, each major-node row circumscribing longitudinal axis ax1 at a respective major-node-row longitudinal site, and minor nodes <NUM> are typically arranged in minor-node rows, each minor-node row circumscribing the longitudinal axis at a respective minor-node-row longitudinal site. Along at least part of axis ax1, the minor-node-row longitudinal sites alternate with the major-node-row longitudinal sites. For some applications, along at least this part of axis ax1, at least <NUM> minor-node-row longitudinal sites alternate with at least <NUM> major-node-row longitudinal sites, e.g., in the order minor-major-minor-major-minor, as shown.

Reference is now made to <FIG>, which are schematic illustrations of an inner frame 330b, and an implant 320b comprising inner frame 330b.

Inner frame 330b may be used in place of other inner frames of implants described herein, mutatis mutandis.

Inner frame 330b comprises a valve body (which is a generally tubular portion) 332b that has an upstream end 334b and a downstream end 336b, and is shaped to define a lumen through the valve body from its upstream end to its downstream end. Valve frame 330b further comprises a plurality of arms <NUM>, each of which, in the expanded state, extends radially outward from valve body 332b. Inner frame 330b is typically the same as inner frame 330a, except where noted. Compared to inner frame 330a, inner frame 330b comprises additional joists <NUM> at upstream end 334b. That is, in contrast to inner frame 330a, for inner frame 330b pairs <NUM> of joists are also disposed at the upstream side of the upstream row of cells.

In frame 330a, sites <NUM> are coincident with the upstream extremity of a respective upstream-row cell. In contrast, in frame 330b, sites <NUM> are not coincident with the upstream extremity of a respective upstream-row cell. Rather, sites <NUM> are coincident with a minor node that joins the joists that are paired with (e.g., that are parallel with) the joists of the respective upstream-row cell.

Implant 320b is typically the same as implant 320a, except that it comprises inner frame 330b instead of inner frame 330a.

Reference is now made to <FIG>, which are schematic illustrations of an inner frame 330c, and an implant 320c comprising inner frame 330c.

Inner frame 330c may be used in place of other inner frames of implants described herein, mutatis mutandis.

Inner frame 330c comprises a valve body (which is a generally tubular portion) 332c that has an upstream end 334c and a downstream end 336c, and is shaped to define a lumen through the valve body from its upstream end to its downstream end. Valve frame 330c further comprises a plurality of arms <NUM>, each of which, in the expanded state, extends radially outward from valve body 332c. Inner frame 330c is typically the same as inner frame 330b, except where noted.

In general, for implants having an expandable cellular structure, such as the valve bodies described herein, for a given size of the implant, a cellular structure that defines fewer, larger cells, advantageously facilitates radial compression (i.e., "crimping") to a smaller diameter than does a comparable cellular structure that defines more, smaller cells. However, this is typically at the expense of strength and rigidity of the expanded valve. As described hereinabove, the presence of additional joists <NUM> (e.g., in inner frames 330a, 330b, and 330c) to form pairs <NUM> is hypothesized to increase strength and rigidity, in particular with respect to compression toward the central longitudinal axis. As a result, it is further hypothesized by the inventors that using such a paired joist cellular structure facilitates reducing the number, and increasing the size, of the cells of the valve body, in order to achieve a valve body that is radially compressible to a smaller diameter while maintaining sufficient strength and rigidity.

Accordingly, valve body 332c of inner frame 330c has fewer, larger cells compared to valve body <NUM> of inner frame <NUM>, and is therefore radially compressible to a smaller diameter. Whereas each row of cells of valve body <NUM> includes <NUM> cells, each row of cells of valve body 332c includes <NUM> cells. More generally, whereas the rotationally-symmetrical pattern of valve body <NUM> has <NUM> repeats (e.g., <NUM> cells per cell row, <NUM> minor nodes per minor-node row, <NUM> major nodes per major-node row, <NUM> coupling elements, <NUM> arms <NUM>), the rotationally-symmetrical pattern of valve body 332c has only <NUM> repeats. (Both valve body <NUM> and valve body 332c typically have <NUM> appendages <NUM> and <NUM> projections <NUM>. ) Both valve body <NUM> and valve body 332c define two rows of cells. Therefore, whereas valve body <NUM> defines <NUM> cells in total, valve body 332c defines <NUM> cells in total. Whereas valve body <NUM> defines exactly <NUM> major nodes, valve body 332c defines exactly <NUM> major nodes.

For some applications, and as shown, inner frame 330c comprises additional joists <NUM> at upstream end 334c (e.g., similarly to inner frame 330b). That is, for such applications, pairs <NUM> of joists are typically also disposed at the upstream side of the upstream row of cells of inner frame 330c. For such applications, implant 320c is typically the same as implant 320b, except that implant 320c comprises <NUM> rotationally-symmetrical repeats, rather than <NUM>.

For some applications, inner frame 330c does not comprise additional joists <NUM> at upstream end 334c, and is instead more like inner frame 330a in this regard.

Reference is again made to <FIG>. It is to be noted that although the above-described arrangements of joists connected at major and minor nodes are described in the context of a prosthetic heart valve, the scope of the disclosure includes using such arrangements in other implants or components thereof that comprise a cellular structure, such as stents.

Reference is made to <FIG>, which are schematic illustrations of a technique for use with a frame of a prosthetic valve.

The technique is for augmenting a tissue-engaging flange of the frame with a soft pad <NUM>. To illustrate the technique, <FIG> show the technique being used to augment flanges <NUM> of outer frame <NUM> with soft pads <NUM>, but it is to be noted that the technique may be used with any suitable frame, mutatis mutandis.

<FIG> shows frame <NUM>, which has tissue-engaging flanges <NUM>. A model <NUM> of a soft pad <NUM> with which each flange <NUM> is to be augmented is affixed to the respective flange (<FIG>). Subsequently, a mold <NUM> is formed by (i) positioning frame <NUM> such that models <NUM> are supported within a fluid 310f of a first substance <NUM> while the first substance solidifies, and (ii) subsequently, removing the models from the first substance, leaving a cavity in the solidified first substance. For example, and as shown in <FIG>, a bath <NUM> of fluid 310f may be prepared, and frame <NUM> may be inverted and lowered into the bath such that models <NUM> are supported within the fluid (<FIG>). First substance <NUM> is allowed to solidify into solidified first substance <NUM> (<FIG>). Subsequently, frame <NUM> is withdrawn from the bath, thereby removing models <NUM> from solidified first substance <NUM>, such that each model leaves a respective cavity <NUM> in solidified first substance <NUM> (<FIG>).

Models <NUM> are then removed from flanges <NUM> (<FIG>). Pads <NUM> are then formed by: (i) placing flanges <NUM> in contact with a second substance <NUM> by repositioning the frame such that each flange is supported within a respective cavity <NUM>, and introducing a fluid 312f of the second substance to the cavity (<FIG>), and (ii) while the flange remains in contact with the second substance, allowing the second substance to solidify into solidified second substance <NUM> and to become affixed to the flange. Subsequently, flanges <NUM> are removed from cavities <NUM> with formed pads <NUM> (comprising solidified second substance <NUM>) affixed to the flanges (<FIG>).

The technique described with reference to <FIG> may be used with a frame that has a single tissue-engaging flange. However, as shown, the technique is typically used with a frame that has a plurality of flanges, e.g., to augment all the flanges simultaneously. It is to be noted that flanges <NUM> are not all disposed on the same side of frame assembly <NUM> (i.e., after frames <NUM> and <NUM> have been attached to each other). For example, flanges <NUM> are not all at the upstream end of the prosthetic valve or at the downstream end of the prosthetic valve. Rather, they are disposed downstream of the tips of arms <NUM> and upstream of downstream end <NUM>. Furthermore, flanges <NUM> are arranged circumferentially around the longitudinal axis of the prosthetic valve. Flanges <NUM> (and eventually pads <NUM>) are arranged circumferentially around frame <NUM> longitudinally between the upstream end and the downstream end of frame <NUM>, exclusive. For some applications, the flanges being not all disposed on the same side might inhibit the use of the technique of <FIG> to simultaneously augment all of the flanges. For example, it may be difficult to place all of models <NUM> into the fluid first substance, or to place all of flanges <NUM> into the fluid second substance, without also placing other portions of the frame assembly into the fluid substance. The two-frame nature of frame assembly <NUM> advantageously allows flanges <NUM> to be augmented with pads before frame <NUM> is attached to frame <NUM>. Because all of flanges <NUM> are disposed at the same side (e.g., the upstream side) of frame <NUM>, they can all be placed into the fluid substances simultaneously.

An alternative solution is also contemplated by the inventors, in which an annular bath is positioned circumscribing the central portion of the prosthetic valve or frame assembly, such that all flanges can be placed into the fluid substances even when the flanges are not all disposed on the same side of a prosthetic valve or frame assembly.

For some applications, substance <NUM> and/or substance <NUM> may be a mixture of constituents that is initially fluid upon mixing, and that solidifies as the constituents react with each other. For some applications, fluid substance 310f and/or fluid substance 312f is fluid because it is in a molten state, and solidifies as it cools. When solidified, second substance <NUM> is typically soft, flexible, and/or resilient. For some applications, second substance <NUM> (or at least solidified second substance <NUM>) is a foam. For some applications, second substance <NUM> comprises silicone, polyurethane, a thermoplastic elastomer such as Santoprene (TM), and/or polyether block amide.

For some applications, the techniques described with reference to <FIG> are alternatively or additionally used, mutatis mutandis, to augment the downstream end of the implant with one or more pads, e.g., to serve a similar function to ring <NUM> described hereinabove.

Reference is made to <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, which are schematic illustrations of an implant <NUM>, and steps in the assembly of the implant, in accordance with some applications of the invention. In particular, these figures illustrate steps in the attachment of various flexible components to the frame assembly of the implant, such as steps in the dressing of the frame assembly with various sheets of flexible material. Implant <NUM> is shown as comprising frame assembly <NUM>, and is typically identical to implant <NUM> except for where described otherwise. However, it is to be noted that the steps described with reference to <FIG> may be used, mutatis mutandis, to assemble other implants, including the other implants described herein.

<FIG> show flexible components of implant <NUM>. <FIG> are perspective and side views, respectively, of a valvular assembly <NUM>, comprising leaflets <NUM> arranged to serve as a check valve. In valvular assembly <NUM>, each leaflet <NUM> defines (i) an upstream surface <NUM>, past which blood will flow through implant <NUM> in an upstream-to-downstream direction, and (ii) a downstream surface <NUM>, against which blood will press when the valvular assembly closes and inhibits blood flow in a downstream-to-upstream direction. Valvular assembly <NUM> typically further comprises a liner <NUM> and/or a plurality of connectors <NUM>. Liner <NUM> of implant <NUM> generally corresponds to liner <NUM> of implant <NUM>, mutatis mutandis. Typically, valvular assembly <NUM> comprises three leaflets <NUM> and three connectors <NUM>. Connectors <NUM> couple the leaflets to each other to form commissures, and are used to secure the leaflets, at the commissures, to frame assembly <NUM>. Connectors <NUM> are arranged circumferentially, and leaflets <NUM> extend radially inward from the connectors. For some applications, valvular assembly <NUM>, and connectors <NUM> in particular, are as described in <CIT>, and/or <CIT>.

Each leaflet <NUM> is attached (e.g., stitched) to liner <NUM> along a line (e.g., a stitch line) <NUM>. Each leaflet <NUM> defines a free edge <NUM>, which is typically straight, and at which the leaflet coapts with the other leaflets <NUM>. Stitch line <NUM> is typically curved. Each leaflet typically defines a curved edge (e.g., an upstream edge) <NUM> at which the leaflet is attached to liner <NUM>. The curve of edge <NUM> and/or stitch line <NUM> is concave toward the downstream end of valvular assembly <NUM>, such that edge <NUM> and/or stitch line <NUM> (i) become closer to the downstream end of the valvular assembly at connectors <NUM>, and (ii) are closest to the upstream end of the valvular assembly about midway circumferentially between the connectors. That is, edge <NUM> has an apex about midway circumferentially between connectors <NUM>.

Typically, and as shown, leaflets <NUM> extend further axially downstream (i.e., downstream with respect to axis ax1) than does liner <NUM>. Therefore, a downstream portion of each leaflet <NUM> is typically circumferentially exposed from liner <NUM>. For some applications, and as shown, liner <NUM> is shaped to define regions <NUM> at which a downstream edge <NUM> of the liner recedes from the downstream end of valvular assembly <NUM>. At each region <NUM>, more of the respective leaflet <NUM> is circumferentially exposed. Each region <NUM> is typically circumferentially aligned with the concavity defined by edge <NUM> and/or stitch line <NUM>. At regions <NUM>, downstream edge <NUM> of liner <NUM> is typically stitched to ring <NUM> of frame <NUM>. Therefore, for some applications, the most upstream parts of downstream edge <NUM> of liner <NUM> are closer to the upstream end of the implant than is the most downstream parts of arms <NUM>. As described in more detail hereinbelow, in implant <NUM>, regions <NUM> of liner <NUM> facilitate the provision of windows <NUM> into a pouch <NUM>.

<FIG> shows a sheet <NUM> of flexible material. Typically, and as shown, sheet <NUM> is provided flat, and in the shape of a major arc of an annulus, having a first arc-end 442a and a second arc-end 442b. Sheet <NUM> of implant <NUM> generally corresponds to annular sheet <NUM> of implant <NUM>, mutatis mutandis.

<FIG> shows a sheet <NUM> of flexible material. Sheet <NUM> is annular, and defines an inner perimeter <NUM>, an outer perimeter <NUM>, and a radial dimension d21 therebetween.

<FIG> shows a sheet <NUM> of flexible material. Sheet <NUM> is shaped to define a belt <NUM> and a plurality of elongate strips <NUM>. Each strip <NUM> defines a respective central strip-axis ax2, and extends along its strip-axis from belt <NUM> to the end <NUM> of the strip. Typically, belt <NUM> is linear and defines a belt-axis ax3, and strip-axis ax2 is orthogonal to the belt-axis. Typically, strips <NUM> are parallel to each other. Each strip <NUM> has first and second edges <NUM> (e.g., a first edge 468a and a second edge 468b), which extend on either side of axis ax2, between belt <NUM> and end <NUM>.

As indicated by the reference numeral <NUM>, sheets <NUM>, <NUM>, and <NUM> may all be considered components of sheeting <NUM>. For some applications, liner <NUM>, sheet <NUM>, sheet <NUM>, and/or <NUM> comprise (e.g., consist of) the same material as each other. Typically, sheets <NUM>, <NUM>, and <NUM> are provided as flat, and are subsequently shaped during assembly of implant <NUM>, e.g., as described hereinbelow.

For applications in which sheet <NUM> is provided flat and in the shape of a major arc of an annulus, sheet <NUM> is shaped into an open frustum by attaching (e.g., stitching) ends 442a and 442b together (<FIG>). This is represented by a stitch line <NUM> in <FIG>. Alternatively, sheet <NUM> may be provided in the open frustum shape. The open frustum shape has a greater perimeter <NUM> at a first base of the frustum, and a smaller perimeter <NUM> at a second base of the frustum. Perimeter <NUM> defines an opening, and sheet <NUM> is stitched to arms <NUM> such that the opening is aligned with the lumen defined by valve body <NUM> of frame <NUM> (<FIG>), and typically such that the sheet covers an upstream side of the arms. <FIG> shows valvular assembly <NUM> having been coupled to frame assembly <NUM>. This step may be performed after sheet <NUM> is stitched to arms <NUM> (as shown) or beforehand. Valvular assembly <NUM> is placed inside valve body <NUM> of frame <NUM>, and is attached by stitching connectors <NUM> and liner <NUM> to frame assembly <NUM>. Connectors <NUM> are typically stitched to ring <NUM> and/or ring <NUM>. For some applications, the attachment of connectors <NUM> to frame assembly <NUM> is as described in <CIT>, and/or <CIT>.

Smaller perimeter <NUM> of sheet <NUM> is stitched to an upstream edge <NUM> of liner <NUM>, to form a substantially sealed channel through implant <NUM>. This stitching is represented by a stitch line <NUM>. Typically, and as shown, projections <NUM> extend between, and are sandwiched between, perimeter <NUM> of sheet <NUM> and upstream edge <NUM> of liner <NUM>. Upstream edge <NUM> is typically circular.

Downstream edge <NUM> of liner <NUM> is stitched to valve body <NUM> of frame <NUM>. Typically, downstream edge <NUM> is shaped and positioned to approximately conform to rings <NUM> and <NUM>, and is stitched to these rings.

It is to be noted that throughout this patent application (including the specification and the claims) stitching of a perimeter or edge of a sheet to a perimeter or edge of another sheet, does not necessarily mean that the sheets are stitched at their absolute edges (i.e., their free edges). Rather, in this context, the "perimeter" or "edge" also includes the adjacent area of the sheet, as is understood by one of ordinary skill in the stitching art, and as is typically required for effective stitching.

Valvular assembly <NUM> is typically positioned within frame assembly such that the apex of curved edge <NUM> of each leaflet <NUM> is disposed axially close to (e.g., axially within <NUM> of, e.g., within <NUM> of) an upstream end <NUM> of valve body <NUM>. Valvular assembly <NUM> is also typically positioned within frame assembly such that free edge <NUM> of each leaflet <NUM> is disposed downstream of leg <NUM>.

Subsequently, sheet <NUM> is attached to frame assembly <NUM> (<FIG>). Outer perimeter <NUM> of sheet <NUM> is stitched to greater perimeter <NUM> of the sheet <NUM> (<FIG>). This is represented by stitch line <NUM>. Typically, perimeter <NUM> is larger than perimeter <NUM>, and is brought inwards to be stitched to perimeter <NUM> (e.g., making sheet <NUM> frustoconical), with inner perimeter <NUM> disposed axially away from frame assembly <NUM> (e.g., further axially away than outer perimeter <NUM> from the frame assembly).

Subsequently, sheet <NUM> is everted by bringing inner perimeter <NUM> toward frame assembly <NUM>, and passing the inner perimeter around the tips of arms <NUM> - i.e., axially past the tips of all of the arms (<FIG>). Typically, and as shown, arms <NUM> collectively define an arm-span d23 that is wider than perimeter <NUM>. That is, the tips of arms <NUM> typically define a perimeter that is greater than perimeter <NUM>. For some applications, the passage of inner perimeter <NUM> around the tips of arms <NUM> is facilitated by bending (e.g., temporarily) one or more of arms <NUM>.

Inner perimeter <NUM> is advanced over at least part of valve body <NUM> toward a downstream end of frame assembly <NUM>, and is stitched in place. Typically, perimeter <NUM> is advanced between the valve body and legs <NUM>, such that perimeter <NUM> circumscribes valve body <NUM>, and legs <NUM> are disposed radially outside of sheet <NUM>. As described hereinabove, each leg <NUM> extends radially outward and in an upstream direction from a respective leg-base <NUM> to a respective leg-tip <NUM>. Each leg therefore extends at an acute angle to define a respective cleft <NUM> between the leg and valve body <NUM> (e.g., the tubular portion), the cleft open to the upstream direction. Typically, perimeter <NUM> is tucked into clefts <NUM>, and is stitched into place. Frame assembly <NUM> defines a distance d22, measured along a straight line, between the ends of arms <NUM> and clefts <NUM>. For clarity, distance d22 may be defined as a distance between (i) an imaginary ring described by the ends of arms <NUM>, and (ii) an imaginary ring described by clefts <NUM>.

The dimensions and positioning of sheet <NUM> defines an inflatable pouch <NUM> that is bounded by sheet <NUM> (e.g., defining an outer and/or downstream wall of the pouch), sheet <NUM> (e.g., defining an upstream wall of the pouch), and liner <NUM> (e.g., defining an inner wall of the pouch). Pouch <NUM> typically circumscribes the longitudinal axis of the implant and/or the valve body of frame assembly <NUM> (e.g., the pouch is a cuff), and further typically extends radially outward from the valve body. Typically, an upstream portion of pouch <NUM> is attached to valve frame <NUM> (e.g., and is not attached to outer frame <NUM>), and a downstream portion of the pouch is attached to the outer frame. As described in more detail hereinbelow, at least one respective window <NUM> into pouch <NUM> is defined between each leaflet <NUM> and perimeter <NUM>.

<FIG> show steps in dressing frame assembly <NUM> with sheet <NUM>, in accordance with some applications of the invention. Each strip <NUM> is formed into a respective pocket <NUM> (<FIG>). Each strip is folded over itself, about a fold-line <NUM> that is orthogonal to strip-axis ax2, thereby forming (i) a first strip-portion 464a that extends from belt <NUM> to the fold-line, and (ii) a second strip-portion 464b that extends from fold-line back toward the belt. First strip-portion 464a and second strip-portion 464b are stitched together at first edge 468a and second edge 468b. The resulting pocket <NUM> is typically elongate, and has (i) an opening <NUM> defined at least in part by end <NUM> of the strip, and (ii) a tip <NUM> at the fold-line.

For some applications, a soft pad <NUM> is provided in each pocket <NUM>, typically at tip <NUM>. For some such applications, and as shown in <FIG>, pad <NUM> is formed from a piece of foam <NUM> (e.g., comprising polyurethane). Piece of foam <NUM> may initially be generally cubic. For some applications, and as shown, piece of foam <NUM> is folded to form a niche <NUM> in pad <NUM>, typically after having been at least partly flattened by compression. Pad <NUM> may be introduced into pocket <NUM> before the pocket is fully formed (e.g., as shown), or may be subsequently introduced into the pocket via opening <NUM>.

Alternatively, pads <NUM> may be used in place of pads <NUM>, and may be added to flanges <NUM> as described with reference to <FIG>, mutatis mutandis.

For applications in which pad <NUM> is used, each strip-portion 464a and 464b typically defines a widened region <NUM> adjacent to fold-line <NUM>, such that when pockets <NUM> are formed, a receptacle for pad <NUM> is formed.

Pockets <NUM> are subsequently slid onto legs <NUM>, and belt <NUM> is wrapped around frame assembly <NUM> downstream of legs <NUM> (e.g., downstream of the axial level at which the legs are coupled to the valve body). Belt <NUM> is typically positioned such that it is disposed over the commissures of leaflets <NUM> and/or over connectors <NUM>. That is, the belt is typically wrapped around the frame assembly at an axial level such t For applications in which pads <NUM> are used, flanges <NUM> of legs <NUM> are typically advanced into niches <NUM> of the pads. Belt <NUM> (e.g., the edge of the belt from which pockets <NUM> extend) is stitched to sheet <NUM>. More specifically, the upstream edge of belt <NUM> is stitched circumferentially to perimeter <NUM> of sheet <NUM>. This is represented by a stitch line <NUM>. Therefore, once implant <NUM> is assembled, the edge of belt <NUM> from which pockets <NUM> extend is an upstream edge of the belt, while the edge that is closest to the downstream end of the implant is a downstream edge of the belt. Legs <NUM>, within pockets <NUM>, extend radially outward from between belt <NUM> and sheet <NUM> (e.g., at stitch line <NUM>).

For some applications, tips <NUM> and/or pads <NUM> are further secured to flanges <NUM> by stitching <NUM>, which may pass through a hole <NUM> (labeled in <FIG>) defined in each flange <NUM>. Stitching <NUM> is visible in <FIG>.

As shown in <FIG>, for some applications, polytetrafluoroethylene ring <NUM> is typically also attached to frame assembly <NUM>. For some such applications, in addition to being stitched to frame assembly <NUM>, ring <NUM> is also stitched to belt <NUM> (e.g., to the edge of the belt opposite pockets <NUM> - i.e., the downstream edge of the belt).

<FIG> shows a ribbon <NUM> being wrapped around the leg-base <NUM> of each leg <NUM>, in accordance with some applications of the invention. For some applications, the ends of ribbon <NUM> overlap. Ribbons <NUM> are stitched in place, but the stitches are typically not disposed in cleft <NUM>. As shown, ribbons <NUM> may be stitched to belt <NUM>. Although ribbons <NUM> are shown being used in combination with pockets <NUM> (and are therefore wrapped around the pockets at leg-base <NUM>), it is to be noted that ribbons <NUM> may alternatively be used for applications in which legs <NUM> are generally uncovered. Ribbon <NUM> covers cleft <NUM>, and is hypothesized by the inventors to reduce a likelihood of tissue (e.g., leaflet or chordae tissue) from becoming wedged in and/or damaged by the cleft.

<FIG> show implant <NUM> after its assembly. <FIG> is an upper perspective view (e.g., showing upstream surfaces of the implant), <FIG> shows a side view, and <FIG> shows a lower perspective view (e.g., showing downstream surfaces of the implant).

As described with reference to <FIG>, implant <NUM> (which comprises frame assembly <NUM>) is secured in place at the native valve by sandwiching tissue of the native valve between the implant's upstream support portion <NUM> and flanges <NUM>. Implants that comprise frame assembly <NUM>, such as implant <NUM>, are typically secured in the same way, mutatis mutandis. Implants that further comprise pouch <NUM>, such as implant <NUM>, are typically secured similarly, but with pouch <NUM> disposed between the upstream support portion and the tissue of the native valve. Therefore in at least some regions of implant <NUM>, the tissue of the native valve is sandwiched between flanges <NUM> and pouch <NUM>, e.g., as shown in <FIG>.

Windows <NUM> open into pouch <NUM> from the lumen of the valve body. Once implant <NUM> has been implanted at the native valve, windows <NUM> are disposed functionally within ventricle <NUM>, whereas at least portions of pouch <NUM> are disposed functionally within atrium <NUM>. Therefore, during ventricular systole, ventricular pressure (which is much greater than atrial pressure) forces blood into pouch <NUM>, thereby inflating the pouch. This inflation presses pouch <NUM> against the tissue of the native valve. It is hypothesized by the inventors that this inhibits paravalvular leakage of blood, especially during ventricular systole. For example, the pouch may seal a paravalvular gap at the commissures of the native valve. For some applications, inflation of pouch <NUM> squeezes tissue of the native valve (e.g., native leaflets) between the pouch and flanges <NUM>. Pouch <NUM> is typically dimensioned such that if, in a particular region, tissue is not disposed between a flange <NUM> and pouch <NUM>, inflation of the pouch presses the pouch against the flange.

There is therefore provided, in accordance with an application of the present invention, apparatus, comprising:.

The first sheet, the second sheet, and the liner define inflatable pouch <NUM> therebetween, the first sheet defining an upstream wall of the pouch, the second sheet defining a radially-outer wall of the pouch, and the liner defining a radially-inner wall of the pouch. The apparatus defines a plurality of windows (e.g., windows <NUM>) from the lumen into the pouch, each of the windows bounded by the liner at upstream edges of the window, and bounded by the second perimeter and/or belt <NUM> at a downstream edge of the window. Each window <NUM> is typically discrete - i.e., bounded on all sides, and separate from other windows. For some applications in which downstream edge <NUM> of liner <NUM> is stitched to ring <NUM> of frame <NUM>, the most upstream parts of windows <NUM> are closer to the upstream end of the implant than are the most downstream parts of arms <NUM>.

Typically, and as shown, pouch <NUM> circumscribes the valve body of implant <NUM>.

Typically, and as shown in <FIG>, each window <NUM> spans more than one cell of the valve body. This is represented by the multiple instances of reference numeral <NUM> in <FIG>. For some applications, and as shown, each window spans at least partly of five cells of the valve body. For some such applications, and as shown, each window spans substantially all of two cells (e.g., two cells of row 29a) and about half (e.g., <NUM>-<NUM> percent) of each of three cells (e.g., three cells of row 29b). Each window <NUM> is bounded by liner <NUM> at an upstream edge of the window. Typically, and as shown, the upstream edge of each window <NUM> is defined at rings <NUM> and <NUM> of valve frame <NUM>, at which region <NUM> of liner <NUM> is stitched to the valve frame. At the downstream edge of each window, the window is bounded by perimeter <NUM>, and also by belt <NUM>. Therefore, at the downstream edge of each window <NUM>, the window may be considered to be bounded by stitch line <NUM>.

For some applications, the upstream edge of each window <NUM> is the shape of a capital letter M, e.g., with the apices of the letter M at upstream end <NUM> of the valve body, and with the vertex of the letter M at a site <NUM>. Because region <NUM> of liner <NUM> follows, and is stitched to, the joists of valve frame <NUM> at region <NUM> of the liner, it is hypothesized by the inventors that this arrangement reinforces the upstream edge of window <NUM>, e.g., increasing durability compared to an arrangement in which the upstream edge of the window crosses between joists of the valve frame.

As described hereinabove, sheet <NUM> typically covers an upstream side of arms <NUM>. Once pouch <NUM> has been formed, at least most of each arm <NUM> is therefore disposed inside the pouch. As also described hereinabove, sheet <NUM> is stitched to arms <NUM>. Once pouch <NUM> has been formed, the pouch (i.e., the part of the pouch defined by sheet <NUM>) is therefore stitched to arms <NUM>,.

For some applications, a circumferential stitch line <NUM> is used to stitch sheet <NUM> to sheet <NUM> at a radius smaller than the overall radius of upstream support portion <NUM> (i.e., radially inward from the tips of arms <NUM>), typically sandwiching arms <NUM> between these two sheets. Stitch line <NUM> is typically radially aligned with region <NUM> and/or wide (and flexible) portion 46c of arm <NUM>. This typically creates a region <NUM> in which the portions of sheets <NUM> and <NUM> that are disposed radially outward from stitch line <NUM> are isolated from pouch <NUM>. For such applications, the ends of arms <NUM> are therefore typically disposed in region <NUM>, and are isolated from pouch <NUM>.

For some applications, and as shown, sheet <NUM> is sufficiently baggy that the sheet (e.g., pouch <NUM>) may extend radially outward beyond arms <NUM>, particularly if uninhibited by tissue of the native valve. This may be achieved by radial dimension d21 of sheet <NUM> being greater than distance d22 between the ends arms <NUM> and clefts <NUM>. For some applications, dimension d21 is more than <NUM> percent greater (e.g., more than <NUM> percent greater) than distance d22. For example, dimension d21 may be <NUM>-<NUM> percent greater (e.g., <NUM>-<NUM> percent greater, e.g., <NUM>-<NUM> percent greater, such as <NUM>-<NUM> percent greater) than distance d22. As shown, pouch <NUM> may extend radially outward beyond arms <NUM> irrespective of the presence of stitch line <NUM>, which is disposed radially-inward from the ends of arms <NUM>.

Regarding the axial position (i.e., the position along the longitudinal axis of implant <NUM>) of pouch <NUM> and windows <NUM>. For some applications, pouch <NUM> extends, with respect to the longitudinal axis of implant <NUM>, further upstream than the leaflets. That is, for some applications, upstream regions of pouch <NUM> (e.g., those closest to prosthetic valve support <NUM>) are situated further upstream than even the apex of curved edge <NUM> of leaflets <NUM>. For some applications, and as shown, each of leaflets <NUM> is attached to liner <NUM> upstream of windows <NUM>. That is, at least the apex of curved edge <NUM> of leaflets <NUM> is disposed upstream of windows <NUM>. Free edge <NUM> of each leaflet <NUM> is typically disposed downstream of the third axial level - i.e., the axial level at which perimeter <NUM> of sheet <NUM> is attached to frame assembly <NUM>. That is, leaflets <NUM> typically extend further downstream than pouch <NUM>. For some applications, and as shown, the third axial level (i.e., the axial level at which perimeter <NUM> of sheet <NUM> is attached to frame assembly <NUM>) is upstream of the second axial level (i.e., the axial level at which legs <NUM> are attached to the valve body).

It is to be noted that, whereas liner <NUM> is disposed on the inside of valve body <NUM>, sheet <NUM> and belt <NUM> are disposed on the outside of the valve body. Axially downstream of windows <NUM>, valve body <NUM> is typically not lined - i.e., no liner is typically disposed between leaflets <NUM> and frame <NUM>. However, belt <NUM> circumscribes valve body <NUM> and serves a similar function to a liner - channeling fluid through the lumen of the valve body.

It is to be noted that projections <NUM> are not visible in <FIG>. For some applications, and as shown, the projection-length of projections <NUM> (e.g., see projection-length d13 in <FIG>) is such that the projections do not extend further upstream than the tips of arms <NUM>. For some applications, and as shown, projections <NUM> extend further upstream than the highest part of arms <NUM> within concave region <NUM>. For some applications, and as shown, projections <NUM> extend to an axial height that is between (a) that of the tips of arms <NUM>, and (b) that of the highest part of arms <NUM> within concave region <NUM>. This is illustrated perhaps most clearly in <FIG>, which shows inner frame 330a, but is applicable to each of the inner frames described herein, mutatis mutandis.

Reference is made to <FIG>, and <FIG>, which are schematic illustrations of implant <NUM>, in accordance with some applications of the invention. Pouch <NUM> defines an interior space <NUM>. For some applications, and as shown, arms <NUM> and legs <NUM> (e.g., flanges <NUM> thereof) narrow pouch <NUM> therebetween to form a narrowed portion <NUM> of the pouch. Narrowed portion <NUM> typically circumscribes valve body <NUM> and/or the longitudinal axis of the implant - e.g., the narrowed portion being annular. This thereby defines (i) an inner portion <NUM> of the interior space, radially inward from narrowed portion <NUM>, and in fluid communication with lumen <NUM> of the implant (e.g., via windows <NUM>), and (ii) an outer portion <NUM> of the interior space, radially outward from the narrowed portion, and in fluid communication with inner portion <NUM> via the narrowed portion. At narrowed portion <NUM> each leg <NUM> (e.g., flange <NUM> thereof) typically pushes sheet <NUM> (which defines a downstream surface of pouch <NUM>) toward sheet <NUM> (which defines an upstream surface of the pouch), such as pressing sheet <NUM> into contact with sheet <NUM>.

Typically, and as shown, arms <NUM> and legs <NUM> alternate circumferentially. That is, when viewed from above, an arm <NUM> is disposed circumferentially on either side of each leg <NUM>, and a leg is disposed circumferentially on either side of each arm. This is illustrated for implant <NUM> in <FIG>, mutatis mutandis. For applications in which arms <NUM> and legs <NUM> alternate circumferentially, at narrowed portion <NUM> each leg <NUM> (e.g., flange <NUM> thereof) forms a respective bulge <NUM> in sheet <NUM> (i.e., the upstream surface of pouch <NUM>) by pressing sheet <NUM> (i.e., the downstream surface of the pouch) against the upstream surface (see <FIG>). Bulges <NUM> are therefore disposed circumferentially between arms <NUM>. It is typically the tip of each leg <NUM> that presses into sheet <NUM>, and therefore bulges <NUM> are typically compact (e.g., as opposed to being elongate).

It is to be noted that narrowed portion <NUM> is therefore formed without pouch <NUM> being sandwiched directly between arms <NUM> and legs <NUM>. It is also to be noted that, at narrowed portion <NUM>, pouch <NUM> is stitched to arms <NUM> but not to legs <NUM>. For some applications, at narrowed portion <NUM>, legs <NUM> extend in an upstream direction past arms <NUM>. (This can be understood from <FIG>, mutatis mutandis). For some applications, this configuration results in sheet <NUM> billowing between legs <NUM>, e.g., as indicated by reference numeral <NUM> in <FIG>.

It is to be noted that the configuration described hereinabove exists in implant <NUM> even prior to implantation - i.e., even in the absence of tissue captured between arms <NUM> and flanges <NUM>.

For some applications of the invention, narrowed portion <NUM> impedes fluid communication between outer portion <NUM> and inner portion <NUM> (and thereby between the outer portion and the lumen of the implant). It is hypothesized by the inventors that, for some such applications, this advantageously inhibits blood that has entered outer portion <NUM>, from exiting the outer portion. During ventricular systole, ventricular pressure forces blood through windows <NUM> into pouch <NUM> (i.e., inner portion <NUM> thereof). At least some of this blood typically enters outer portion <NUM>, e.g., due to the relatively high ventricular pressure. It is hypothesized by the inventors that, at least in part due to narrowed portion <NUM>, during ventricular diastole, pressure in the opposite direction is insufficient to force as much blood back out of outer portion <NUM>. It is further hypothesized by the inventors that, for some applications, this results in a net increase in the volume of blood within outer portion <NUM> during each cardiac cycle, e.g., until resistance inhibits further inflation of outer portion <NUM>. This is illustrated by the sequence of frames A-F in <FIG>, which represent the state of implant <NUM> over time. <FIG> shows blood <NUM> entering outer portion <NUM> only after inner portion <NUM> has become substantially filled (frames C-D), but for some applications blood may begin to enter outer portion <NUM> earlier.

It is hypothesized by the inventors that such a configuration of pouch <NUM> further improves paravalvular sealing provided by the pouch. It is further hypothesized by the inventors that, for some applications of the invention, such a configuration of pouch <NUM> facilitates the pouch (e.g., outer portion <NUM> thereof) conforming to the tissue surrounding implant <NUM>, and therefore further facilitating sealing. For example, <FIG> show implant <NUM> disposed at native valve <NUM>, when the anatomy of the native valve (e.g., the annulus and/or leaflets) are uneven with respect to the implant. For example, the anatomy itself may be particularly uneven, or the implant may have been implanted at a sub-optimal angle with respect to the anatomy. In the example shown, at a zone 520a the anatomy is relatively close to upstream support portion <NUM>, whereas at a zone 520b, the anatomy is relatively spaced apart from the upstream support portion, e.g., resulting in a gap <NUM> (<FIG>). Over time (e.g., between ten seconds and one hour), outer portion <NUM> fills, in each zone, according to the mechanical constraints of that region (<FIG>). In the example shown, in zone 520a outer portion <NUM> inflates with blood until space between upstream support portion <NUM> and the anatomy (e.g., annulus or leaflet tissue) is filled, and the anatomy resists further inflation of the outer portion (<FIG>). In zone 520b outer portion <NUM> continues to inflate with blood because, in this zone, the space between the upstream support portion and the anatomy is larger (<FIG>). In this way, it is hypothesized by the inventors that implant <NUM> advantageously adapts to the native anatomy, providing improved paravalvular sealing.

For some applications, at least one coagulation component <NUM> is disposed within outer portion <NUM>, and is configured to promote blood coagulation within the outer portion. For some applications, coagulation component <NUM> is annular and, within outer portion <NUM>, circumscribes the longitudinal axis of the implant. For some applications, coagulation component <NUM> comprises a fabric (e.g., comprising polyethylene terephthalate). For some applications, coagulation component <NUM> comprises polytetrafluoroethylene (e.g., expanded polytetrafluoroethylene), e.g., in the form of a membrane or ribbon. For some applications, coagulation component <NUM> comprises a metallic (e.g., nitinol or stainless steel) wire, membrane, or mesh, covered by a fabric or expanded polytetrafluoroethylene. For applications, coagulation component comprises a coagulation-inducing drug coated thereon or embedded therein (e.g., within a fabric). For some applications, coagulation component <NUM> comprises pericardial tissue (e.g., bovine or porcine).

For some applications of the invention, the scope of the invention includes using one or more of the apparatus and techniques described in this patent application in combination with one or more of the apparatus and techniques described in one or more of the following documents:.

Claim 1:
Apparatus, comprising:
a frame assembly (<NUM>) that comprises:
a valve body that circumscribes a longitudinal axis and defines a lumen (<NUM>) along the axis;
a plurality of upstream arms (<NUM>) that are coupled to the valve body at a first axial level with respect to the longitudinal axis, each of the arms extending radially outward from the valve body to a respective arm-tip; and
a plurality of downstream legs (<NUM>) that are coupled to the valve body at a second axial level with respect to the longitudinal axis, and that extend radially outward from the valve body and toward the plurality of arms (<NUM>);
a tubular liner (<NUM>) that lines the lumen, and that has an upstream end and a downstream end;
a plurality of prosthetic leaflets (<NUM>), disposed within the lumen (<NUM>), attached to the liner (<NUM>), and arranged to facilitate one-way upstream-to-downstream fluid flow through the lumen (<NUM>), the first axial level being upstream of the second axial level;
a first sheet of flexible material (<NUM>), the first sheet having (i) a greater perimeter (<NUM>), and (ii) a smaller perimeter (<NUM>) that defines an opening, the first sheet (<NUM>) being attached to the plurality of arms (<NUM>) with the opening aligned with the lumen (<NUM>) of the valve body; and
a second sheet (<NUM>) of flexible material:
the second sheet (<NUM>) having a first perimeter and a second perimeter,
the first perimeter being attached to the greater perimeter (<NUM>) of the first sheet (<NUM>) around the greater perimeter (<NUM>) of the first sheet (<NUM>),
the second sheet (<NUM>) extending from the first perimeter radially inwards and downstream toward the second perimeter, the second perimeter circumscribing, and attached to, the valve body at a third axial level that is downstream of the first axial level,
wherein:
the first sheet (<NUM>), the second sheet (<NUM>), and the liner (<NUM>) define an inflatable pouch (<NUM>) therebetween, the inflatable pouch (<NUM>) defining an interior space (<NUM>) therein, the first sheet (<NUM>) defining an upstream wall of the pouch (<NUM>), the second sheet (<NUM>) defining a radially-outer wall of the pouch (<NUM>), and the liner (<NUM>) defining a radially-inner wall of the pouch (<NUM>), and
characterized in that:
each of the legs (<NUM>) presses the second sheet (<NUM>) into contact with the first sheet (<NUM>).