Patent Description:
The human heart can suffer from various valvular diseases. These valvular diseases can result in significant malfunctioning of the heart and ultimately require replacement of the native valve with an artificial valve. There are a number of known artificial valves and a number of known methods of implanting these artificial valves in humans. Because of the drawbacks associated with conventional open-heart surgery, percutaneous and minimally-invasive surgical approaches are garnering intense attention. In one technique, a prosthetic valve is configured to be implanted in a much less invasive procedure by way of catheterization. For example, collapsible transcatheter prosthetic heart valves can be crimped to a compressed state and percutaneously introduced in the compressed state on a catheter and expanded to a functional size at the desired position by balloon inflation or by utilization of a self-expanding frame or stent.

A prosthetic valve for use in such a procedure can include a radially collapsible and expandable frame to which leaflets of the prosthetic valve can be coupled, and which can be percutaneously introduced in a collapsed configuration on a catheter and expanded in the desired position by balloon inflation or by utilization of a self-expanding frame or stent. A challenge in catheter-implanted prosthetic valves is control of perivalvular leakage around the valve, which can occur for a period of time following initial implantation. An additional challenge includes the process of crimping such a prosthetic valve to a profile suitable for percutaneous delivery to a patient.

<CIT> for example discloses a prosthetic heart valve which includes a collapsible and expandable stent having a proximal end and a distal end, and a collapsible and expandable valve assembly, the valve assembly including a plurality of leaflets connected to at least one of the stent and a cuff. The heart valve further includes a conformable band disposed around the perimeter of the stent near the proximal end for filling gaps between the collapsible prosthetic heart valve and a native annulus.

<CIT> discloses another exemplary implantable prosthetic heart valve.

Embodiments of a radially collapsible and expandable prosthetic valve are disclosed herein that include an improved outer skirt for reducing perivalvular leakage, as well as related methods and apparatuses including such prosthetic valves. In several embodiments, the disclosed prosthetic valves are configured as replacement heart valves for implantation into a patient.

The present invention is defined in independent claim <NUM> and relates to an implantable prosthetic heart valve which includes an annular frame, a leaflet structure positioned within the frame and secured thereto, and an annular outer skirt positioned around an outer surface of the frame. The frame includes an inflow end and an outflow end and is radially collapsible and expandable between a radially collapsed configuration and a radially expanded configuration. The frame defines an axial direction extending from the inflow end to the outflow end. The outer skirt includes an inflow edge portion secured to the frame at a first location, an outflow edge portion secured to the frame at a second location, an intermediate portion between the inflow edge portion and the outflow edge portion. The intermediate portion includes a plurality of circumferentially spaced, axially extending slits that define a plurality of skirt segments between each pair of slits, and each skirt segment includes first and second opposing edge portions. At least one of the first and second opposing edge portions of each of the plurality of skirt segments are secured to the frame and/or to other skirt segments so as to produce circumferential and/or twisting movement of the skirt segments upon radial expansion of the frame.

Preferred configurations of the claimed invention are defined in dependent claims <NUM> to <NUM>. In so far as any of the examples described herein are not encompassed by the scope of the claims, they are considered to be as supplementary background information and do not constitute a definition of the claimed invention per se.

In some embodiments, the outer skirt includes a plurality of tethers. Each tether can be secured to the first edge portion of a skirt segment at a first end of the tether, can extend across the second edge portion of the same skirt segment, and can be secured to the frame or an adjacent skirt segment at a second end of the tether such that when the frame is expanded to the radially expanded configuration, the first edge portion is pulled in a circumferential direction toward the second portion by the tether.

In some embodiments, the second end of each tether can be secured to the frame.

In some embodiments, the second end of each tether can be secured to the frame at a location adjacent to the second edge portion of the skirt segment that the first end of the tether is secured to.

In some embodiments, the frame can include a plurality of struts and the second end of each tether can be secured to the frame at a strut adjacent to the second edge portion of the skirt segment that the first end of the tether is secured to.

In some embodiments, each tether can be positioned radially outside of the skirt segment.

In some embodiments, each tether can be positioned radially inside of the skirt segment.

In some embodiments, the tethers can comprise a first set of tethers positioned radially outside of the skirt segment and a second set of tethers positioned radially inside of the skirt segment.

In some embodiments, the tethers can comprise a plurality of first tethers and a plurality of second tethers. In such embodiments, each first tether can have a first end secured to the first edge portion of a respective skirt segment, can extend across the second edge portion of the same skirt segment, and can have a second end secured to the frame at a first location. In such embodiments, each second tether can have a first end secured to the second edge portion of a respective skirt segment, can extend across the first edge portion of the same skirt segment, and can have a second end secured to the frame at a second location. In such embodiments, the first and second locations can be adjacent opposite sides of the skirt segment such that when the frame is expanded to the radially expanded configuration, the second tether pulls the second edge portion toward the first edge portion and the first tether pulls the first edge portion toward the second edge portion.

In some embodiments, the first ethers can be positioned radially outside of the outer skirt and the second tethers can be positioned radially inside of the outer skirt.

In some embodiments, the first ethers and the second tethers can each be positioned radially outside of the outer skirt.

In some embodiments, the first tethers and the second tethers can each be positioned radially inside of the outer skirt.

In some embodiments, the second end of each tether can be secured to an adjacent skirt segment.

In some embodiments, the plurality of tethers can comprise a plurality of first tethers and a plurality of second tethers. In such embodiments, each skirt segment can be coupled to a first adjacent skirt segment by a respective first tether and a second adjacent skirt segment by a respective second tether, such that when the frame is expanded to the radially expanded configuration, the first and second tethers pull the first and second edge portions of the skirt segment toward each other.

In some embodiments, for each skirt segment, a first tether can extend from the first edge portion of the skirt segment across the second edge portion and can be secured to the first adjacent skirt segment, and a second tether can extend from the second edge portion of the skirt segment across the first edge portion, and can be secured to the second adjacent skirt segment.

In some embodiments, the plurality of first tethers can be positioned radially inside of the outer skirt and the plurality of second tethers can be positioned radially outside of the outer skirt.

Also disclosed herein is an exemplary implantable prosthetic valve which can include an annular frame, a leaflet structure positioned within the frame and secured thereto, and an outer sealing member positioned around an outer surface of the frame. The frame can include an inflow end and an outflow end and can be radially collapsible and expandable between a radially collapsed configuration and a radially expanded configuration. The frame can define an axial direction extending from the inflow end to the outflow end. The outer sealing member can include a plurality of sealing segments. Each sealing segment can be coupled to the frame and/or another sealing segment by a tether that pulls a portion of the sealing segment in a circumferential direction when the frame is radially expanded to the expanded configuration.

In some examples, each sealing segment can have upper and lower portions connected to the frame at axially spaced apart locations on the frame that move toward each other upon radial expansion of the frame and cause a portion of the sealing segment to move radially outwardly away from the frame.

In some examples, a width of each sealing segment in a circumferential direction can be reduced by a pulling force of a tether connected to the sealing segment upon radial expansion of the frame.

In some examples, each sealing segment can become at least partially twisted by a pulling force of a tether connected to the sealing segment upon radial expansion of the frame.

In some examples, each tether can have one end secured to a sealing segment and another end secured to the frame or another sealing segment.

The foregoing and other objects, features, and advantages of the disclosure will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.

<FIG> show various views of a prosthetic heart valve <NUM>, according to one embodiment. The illustrated prosthetic valve is adapted to be implanted in the native aortic annulus, although in other embodiments it can be adapted to be implanted in the other native annuluses of the heart (e.g., the pulmonary, mitral, and tricuspid valves). The prosthetic valve can also be adapted to be implanted in other tubular organs or passageways in the body. The prosthetic valve <NUM> can have four main components: a stent or frame <NUM>, a valvular structure <NUM>, an inner skirt <NUM>, and a perivalvular sealing means or sealing member. The prosthetic valve <NUM> can have an inflow end portion <NUM>, an intermediate portion <NUM>, and an outflow end portion <NUM>. In the illustrated embodiment, the perivalvular sealing means comprises an outer skirt <NUM> (which can also be referred to as an outer sealing member).

The valvular structure <NUM> can comprise three leaflets <NUM>, collectively forming a leaflet structure, which can be arranged to collapse in a tricuspid arrangement, as best shown in <FIG>. The lower edge of leaflet structure <NUM> desirably has an undulating, curved scalloped shape (suture line <NUM> shown in <FIG> tracks the scalloped shape of the leaflet structure). By forming the leaflets with this scalloped geometry, stresses on the leaflets are reduced, which in turn improves durability of the prosthetic valve. Moreover, by virtue of the scalloped shape, folds and ripples at the belly of each leaflet (the central region of each leaflet), which can cause early calcification in those areas, can be eliminated or at least minimized. The scalloped geometry also reduces the amount of tissue material used to form leaflet structure, thereby allowing a smaller, more even crimped profile at the inflow end of the prosthetic valve. The leaflets <NUM> can be formed of pericardial tissue (e.g., bovine pericardial tissue), biocompatible synthetic materials, or various other suitable natural or synthetic materials as known in the art and described in <CIT>.

The bare frame <NUM> is shown in <FIG>. The frame <NUM> can be formed with a plurality of circumferentially spaced slots, or commissure windows, <NUM> (three in the illustrated embodiment) that are adapted to connect the commissures of the valvular structure <NUM> to the frame, as described in greater detail below. The frame <NUM> can be made of any of various suitable plastically-expandable materials (e.g., stainless steel, etc.) or self-expanding materials (e.g., nickel titanium alloy (NiTi), such as nitinol). When constructed of a plastically-expandable material, the frame <NUM> (and thus the prosthetic valve <NUM>) can be crimped to a radially collapsed configuration on a delivery catheter and then expanded inside a patient by an inflatable balloon or equivalent expansion mechanism. When constructed of a self-expandable material, the frame <NUM> (and thus the prosthetic valve <NUM>) can be crimped to a radially collapsed configuration and restrained in the collapsed configuration by insertion into a sheath or equivalent mechanism of a delivery catheter. Once inside the body, the prosthetic valve can be advanced from the delivery sheath, which allows the prosthetic valve to expand to its functional size.

Suitable plastically-expandable materials that can be used to form the frame <NUM> include, without limitation, stainless steel, a biocompatible, high-strength alloys (e.g., a cobalt-chromium or a nickel-cobalt-chromium alloys), polymers, or combinations thereof. In particular embodiments, frame <NUM> is made of a nickel-cobalt-chromium-molybdenum alloy, such as MP35N® alloy (SPS Technologies, Jenkintown, Pennsylvania), which is equivalent to UNS R30035 alloy (covered by ASTM F562-<NUM>). MP35N® alloy/UNS R30035 alloy comprises <NUM>% nickel, <NUM>% cobalt, <NUM>% chromium, and <NUM>% molybdenum, by weight. When MP35N® alloy is used as the frame material, as compared to stainless steel, less material is needed to achieve the same or better performance in radial and crush force resistance, fatigue resistances, and corrosion resistance. Moreover, since less material is required, the crimped profile of the frame can be reduced, thereby providing a lower profile prosthetic valve assembly for percutaneous delivery to the treatment location in the body.

Referring to <FIG>, the frame <NUM> in the illustrated embodiment comprises a first, lower row I of angled struts <NUM> arranged end-to-end and extending circumferentially at the inflow end of the frame; a second row II of circumferentially extending, angled struts <NUM>; a third row III of circumferentially extending, angled struts <NUM>; a fourth row IV of circumferentially extending, angled struts <NUM>; and a fifth row V of circumferentially extending, angled struts <NUM> at the outflow end of the frame. A plurality of substantially straight axially extending struts <NUM> can be used to interconnect the struts <NUM> of the first row I with the struts <NUM> of the second row II. The fifth row V of angled struts <NUM> are connected to the fourth row IV of angled struts <NUM> by a plurality of axially extending window frame portions <NUM> (which define the commissure windows <NUM>) and a plurality of axially extending struts <NUM>. Each axial strut <NUM> and each frame portion <NUM> extends from a location defined by the convergence of the lower ends of two angled struts <NUM> to another location defined by the convergence of the upper ends of two angled struts <NUM>. <FIG>, <FIG> are enlarged views of the portions of the frame <NUM> identified by letters A, B, C, D, and E, respectively, in <FIG>.

Each commissure window frame portion <NUM> connects to a respective commissure of the leaflet structure <NUM>. As can be seen each frame portion <NUM> is secured at its upper and lower ends to the adjacent rows of struts to provide a robust configuration that enhances fatigue resistance under cyclic loading of the prosthetic valve compared to cantilevered struts for supporting the commissures of the leaflet structure. This configuration enables a reduction in the frame wall thickness to achieve a smaller crimped diameter of the prosthetic valve. In particular embodiments, the thickness T of the frame <NUM> (<FIG>) measured between the inner diameter and outer diameter is about <NUM> or less.

The struts and frame portions of the frame collectively define a plurality of open cells of the frame. At the inflow end of the frame <NUM>, struts <NUM>, struts <NUM>, and struts <NUM> define a lower row of cells defining openings <NUM>. The second, third, and fourth rows of struts <NUM>, <NUM>, and <NUM> define two intermediate rows of cells defining openings <NUM>. The fourth and fifth rows of struts <NUM> and <NUM>, along with frame portions <NUM> and struts <NUM>, define an upper row of cells defining openings <NUM>. The openings <NUM> are relatively large and are sized to allow portions of the leaflet structure <NUM> to protrude, or bulge, into and/or through the openings <NUM> when the frame <NUM> is crimped in order to minimize the crimping profile.

As best shown in <FIG>, the lower end of the strut <NUM> is connected to two struts <NUM> at a node or junction <NUM>, and the upper end of the strut <NUM> is connected to two struts <NUM> at a node or junction <NUM>. The strut <NUM> can have a thickness S1 that is less than the thicknesses S2 of the junctions <NUM>, <NUM>. The junctions <NUM>, <NUM>, along with junctions <NUM>, prevent full closure of openings <NUM>. <FIG> shows the prosthetic valve <NUM> crimped on a balloon catheter. As can be seen, the geometry of the struts <NUM>, and junctions <NUM>, <NUM>, and <NUM> assists in creating enough space in openings <NUM> in the collapsed configuration to allow portions of the prosthetic leaflets to protrude or bulge outwardly through openings. This allows the prosthetic valve to be crimped to a relatively smaller diameter than if all of the leaflet material were constrained within the crimped frame.

The frame <NUM> is configured to reduce, to prevent, or to minimize possible over-expansion of the prosthetic valve at a predetermined balloon pressure, especially at the outflow end portion of the frame, which supports the leaflet structure <NUM>. In one aspect, the frame is configured to have relatively larger angles 42a, 42b, 42c, 42d, 42e between struts, as shown in <FIG>. The larger the angle, the greater the force required to open (expand) the frame. As such, the angles between the struts of the frame can be selected to limit radial expansion of the frame at a given opening pressure (e.g., inflation pressure of the balloon). In particular embodiments, these angles are at least <NUM> degrees or greater when the frame is expanded to its functional size, and even more particularly these angles are up to about <NUM> degrees when the frame is expanded to its functional size.

In addition, the inflow and outflow ends of a frame generally tend to over-expand more so than the middle portion of the frame due to the "dog-boning" effect of the balloon used to expand the prosthetic valve. To protect against over-expansion of the leaflet structure <NUM>, the leaflet structure desirably is secured to the frame <NUM> below the upper row of struts <NUM>, as best shown in <FIG>. Thus, in the event that the outflow end of the frame is over-expanded, the leaflet structure is positioned at a level below where over-expansion is likely to occur, thereby protecting the leaflet structure from over-expansion.

In one type of prosthetic valve construction, portions of the leaflets protrude longitudinally beyond the outflow end of the frame when the prosthetic valve is crimped if the leaflets are connected too close to the distal end of the frame. If the delivery catheter on which the crimped prosthetic valve is mounted includes a pushing mechanism or stop member that pushes against or abuts the outflow end of the prosthetic valve (for example, to maintain the position of the crimped prosthetic valve on the delivery catheter), the pushing member or stop member can damage the portions of the exposed leaflets that extend beyond the outflow end of the frame. Another benefit of connecting the leaflets at a location spaced away from the outflow end of the frame is that when the prosthetic valve is crimped on a delivery catheter, the outflow end of the frame <NUM> rather than the leaflets <NUM> is the proximal-most component of the prosthetic valve <NUM>. As such, if the delivery catheter includes a pushing mechanism or stop member that pushes against or abuts the outflow end of the prosthetic valve, the pushing mechanism or stop member contacts the outflow end of the frame, and not leaflets <NUM>, so as to avoid damage to the leaflets.

Also, as can be seen in <FIG>, the openings <NUM> of the lowermost row of openings in the frame are relatively larger than the openings <NUM> of the two intermediate rows of openings. This allows the frame, when crimped, to assume an overall tapered shape that tapers from a maximum diameter at the outflow end of the prosthetic valve to a minimum diameter at the inflow end of the prosthetic valve. When crimped, the frame <NUM> can have a reduced diameter region extending along a portion of the frame adjacent the inflow end of the frame that generally corresponds to the region of the frame covered by the outer skirt <NUM>. In some embodiments, the reduced diameter region is reduced compared to the diameter of the upper portion of the frame (which is not covered by the outer skirt) such that the outer skirt <NUM> does not increase the overall crimp profile of the prosthetic valve. When the prosthetic valve is deployed, the frame can expand to the generally cylindrical shape shown in <FIG>. In one example, the frame of a <NUM>-mm prosthetic valve, when crimped, had a first diameter of <NUM> French at the outflow end of the prosthetic valve and a second diameter of <NUM> French at the inflow end of the prosthetic valve.

The main functions of the inner skirt <NUM> are to assist in securing the valvular structure <NUM> to the frame <NUM> and to assist in forming a good seal between the prosthetic valve and the native annulus by blocking the flow of blood through the open cells of the frame <NUM> below the lower edge of the leaflets. The inner skirt <NUM> desirably comprises a tough, tear resistant material such as polyethylene terephthalate (PET), although various other synthetic materials or natural materials (e.g., pericardial tissue) can be used. The thickness of the skirt desirably is less than about <NUM> (about <NUM> mil), and desirably less than about <NUM> (about <NUM> mil), and even more desirably about <NUM> (about <NUM> mil). In particular embodiments, the skirt <NUM> can have a variable thickness, for example, the skirt can be thicker at least one of its edges than at its center. In one implementation, the skirt <NUM> can comprise a PET skirt having a thickness of about <NUM> at its edges and about <NUM> at its center. The thinner skirt can provide for better crimping performances while still providing good sealing.

The skirt <NUM> can be secured to the inside of frame <NUM> via sutures <NUM>, as shown in <FIG>. Valvular structure <NUM> can be attached to the skirt via one or more reinforcing strips <NUM> (which collectively can form a sleeve), for example thin, PET reinforcing strips, discussed below, which enables a secure suturing and protects the pericardial tissue of the leaflet structure from tears. Valvular structure <NUM> can be sandwiched between skirt <NUM> and the thin PET strips <NUM> as shown in <FIG>. Sutures <NUM>, which secure the PET strip and the leaflet structure <NUM> to skirt <NUM>, can be any suitable suture, such as Ethibond Excel® PET suture (Johnson & Johnson, New Brunswick, New Jersey). Sutures <NUM> desirably track the curvature of the bottom edge of leaflet structure <NUM>, as described in more detail below.

Some fabric skirts comprise a weave of warp and weft fibers that extend perpendicularly to each other and with one set of the fibers extending longitudinally between the upper and lower edges of the skirt. When the metal frame to which such a fabric skirt is secured is radially compressed, the overall axial length of the frame increases. However, a fabric skirt with limited elasticity cannot elongate along with the frame and therefore tends to deform the struts of the frame and to prevent uniform crimping.

Referring to <FIG>, in one embodiment, the skirt <NUM> desirably is woven from a first set of fibers, or yarns or strands, <NUM> and a second set of fibers, or yarns or strands, <NUM>, both of which are non-perpendicular to the upper edge <NUM> and the lower edge <NUM> of the skirt. In particular embodiments, the first set of fibers <NUM> and the second set of fibers <NUM> extend at angles of about <NUM> degrees (e.g., <NUM>-<NUM> degrees or <NUM>-<NUM> degrees) relative to the upper and lower edges <NUM>, <NUM>. For example, the skirt <NUM> can be formed by weaving the fibers at <NUM> degree angles relative to the upper and lower edges of the fabric. Alternatively, the skirt <NUM> can be diagonally cut (cut on a bias) from a vertically woven fabric (where the fibers extend perpendicularly to the edges of the material) such that the fibers extend at <NUM> degree angles relative to the cut upper and lower edges of the skirt. As further shown in <FIG>, the opposing short edges <NUM>, <NUM> of the skirt desirably are non-perpendicular to the upper and lower edges <NUM>, <NUM>. For example, the short edges <NUM>, <NUM> desirably extend at angles of about <NUM> degrees relative to the upper and lower edges and therefore are aligned with the first set of fibers <NUM>. Therefore the overall general shape of the skirt can be that of a rhomboid or parallelogram.

<FIG> show the inner skirt <NUM> after opposing short edge portions <NUM>, <NUM> have been sewn together to form the annular shape of the skirt. As shown, the edge portion <NUM> can be placed in an overlapping relationship relative to the opposite edge portion <NUM>, and the two edge portions can be sewn together with a diagonally extending suture line <NUM> that is parallel to short edges <NUM>, <NUM>. The upper edge portion of the inner skirt <NUM> can be formed with a plurality of projections <NUM> that define an undulating shape that generally follows the shape or contour of the fourth row of struts <NUM> immediately adjacent the lower ends of axial struts <NUM>. In this manner, as best shown in <FIG>, the upper edge of the inner skirt <NUM> can be tightly secured to struts <NUM> with sutures <NUM>. The inner skirt <NUM> can also be formed with slits <NUM> to facilitate attachment of the skirt to the frame. Slits <NUM> can be dimensioned so as to allow an upper edge portion of the inner skirt <NUM> to be partially wrapped around struts <NUM> and to reduce stresses in the skirt during the attachment procedure. For example, in the illustrated embodiment, the inner skirt <NUM> is placed on the inside of frame <NUM> and an upper edge portion of the skirt is wrapped around the upper surfaces of struts <NUM> and secured in place with sutures <NUM>. Wrapping the upper edge portion of the inner skirt <NUM> around struts <NUM> in this manner provides for a stronger and more durable attachment of the skirt to the frame. The inner skirt <NUM> can also be secured to the first, second, and/or third rows of struts <NUM>, <NUM>, and <NUM>, respectively, with sutures <NUM>.

Referring again to <FIG>, due to the angled orientation of the fibers relative to the upper and lower edges in this embodiment, the skirt can undergo greater elongation in the axial direction (i.e., in a direction from the upper edge <NUM> to the lower edge <NUM>).

Thus, when the metal frame <NUM> is crimped (as shown in <FIG>), the inner skirt <NUM> can elongate in the axial direction along with the frame and therefore provide a more uniform and predictable crimping profile. Each cell of the metal frame in the illustrated embodiment includes at least four angled struts that rotate towards the axial direction on crimping (e.g., the angled struts become more aligned with the length of the frame). The angled struts of each cell function as a mechanism for rotating the fibers of the skirt in the same direction of the struts, allowing the skirt to elongate along the length of the struts. This allows for greater elongation of the skirt and avoids undesirable deformation of the struts when the prosthetic valve is crimped.

In addition, the spacing between the woven fibers or yarns can be increased to facilitate elongation of the skirt in the axial direction. For example, for a PET inner skirt <NUM> formed from <NUM>-denier yarn, the yarn density can be about <NUM>% to about <NUM>% lower than in a typical PET skirt. In some examples, the yarn spacing of the inner skirt <NUM> can be from about <NUM> yarns per cm (about <NUM> yarns per inch) to about <NUM> yarns per cm (about <NUM> yarns per inch), such as about <NUM> yarns per cm (about <NUM> yarns per inch), whereas in a typical PET skirt the yarn spacing can be from about <NUM> yarns per cm (about <NUM> yarns per inch) to about <NUM> yarns per cm (about <NUM> yarns per inch). The oblique edges <NUM>, <NUM> promote a uniform and even distribution of the fabric material along inner circumference of the frame during crimping so as to facilitate uniform crimping to the smallest possible diameter. Additionally, cutting diagonal sutures in a vertical manner may leave loose fringes along the cut edges. The oblique edges <NUM>, <NUM> help minimize this from occurring.

In alternative embodiments, the skirt can be formed from woven elastic fibers that can stretch in the axial direction during crimping of the prosthetic valve. The warp and weft fibers can run perpendicularly and parallel to the upper and lower edges of the skirt, or alternatively, they can extend at angles between <NUM> and <NUM> degrees relative to the upper and lower edges of the skirt, as described above.

The inner skirt <NUM> can be sutured to the frame <NUM> at locations away from the suture line <NUM> so that the skirt can be more pliable in that area. This configuration can avoid stress concentrations at the suture line <NUM>, which attaches the lower edges of the leaflets to the inner skirt <NUM>.

As noted above, the leaflet structure <NUM> in the illustrated embodiment includes three flexible leaflets <NUM> (although a greater or a smaller number of leaflets can be used). Additional information regarding the leaflets, as well as additional information regarding skirt material, can be found, for example, in <CIT>.

The leaflets <NUM> can be secured to one another at their adjacent sides to form commissures <NUM> of the leaflet structure. A plurality of flexible connectors <NUM> (one of which is shown in <FIG>) can be used to interconnect pairs of adjacent sides of the leaflets and to connect the leaflets to the commissure window frame portions <NUM> (<FIG>).

<FIG> shows the adjacent sides of two leaflets <NUM> interconnected by a flexible connector <NUM>. Three leaflets <NUM> can be secured to each other side-to-side using three flexible connectors <NUM>, as shown in <FIG>. Additional information regarding connecting the leaflets to each other, as well as connecting the leaflets to the frame, can be found, for example, in <CIT>.

As noted above, the inner skirt <NUM> can be used to assist in suturing the leaflet structure <NUM> to the frame. The inner skirt <NUM> can have an undulating temporary marking suture to guide the attachment of the lower edges of each leaflet <NUM>. The inner skirt <NUM> itself can be sutured to the struts of the frame <NUM> using sutures <NUM>, as noted above, before securing the leaflet structure <NUM> to the skirt <NUM>. The struts that intersect the marking suture desirably are not attached to the inner skirt <NUM>. This allows the inner skirt <NUM> to be more pliable in the areas not secured to the frame and minimizes stress concentrations along the suture line that secures the lower edges of the leaflets to the skirt. As noted above, when the skirt is secured to the frame, the fibers <NUM>, <NUM> of the skirt (see <FIG>) generally align with the angled struts of the frame to promote uniform crimping and expansion of the frame.

<FIG> shows one specific approach for securing the commissure portions <NUM> of the leaflet structure <NUM> to the commissure window frame portions <NUM> of the frame. In this approach, the flexible connector <NUM> (<FIG>) securing two adjacent sides of two leaflets is folded widthwise and the upper tab portions <NUM> are folded downwardly against the flexible connector. Each upper tab portion <NUM> is creased lengthwise (vertically) to assume an L-shape having a first portion <NUM> folded against a surface of the leaflet and a second portion <NUM> folded against the connector <NUM>. The second portion <NUM> can then be sutured to the connector <NUM> along a suture line <NUM>. Next, the commissure tab assembly is inserted through the commissure window <NUM> of a corresponding window frame portion <NUM>, and the folds outside of the window frame portion <NUM> can be sutured to second portions <NUM>.

<FIG> also shows that the folded down upper tab portions <NUM> can form a double layer of leaflet material at the commissures. The inner portions <NUM> of the upper tab portions <NUM> are positioned flat against layers of the two leaflets <NUM> forming the commissures, such that each commissure comprises four layers of leaflet material just inside of the window frames <NUM>. This four-layered portion of the commissures can be more resistant to bending, or articulating, than the portion of the leaflets <NUM> just radially inward from the relatively more-rigid four-layered portion. This causes the leaflets <NUM> to articulate primarily at inner edges <NUM> of the folded-down inner portions <NUM> in response to blood flowing through the prosthetic valve during operation within the body, as opposed to articulating about or proximal to the axial struts of the window frames <NUM>. Because the leaflets articulate at a location spaced radially inwardly from the window frames <NUM>, the leaflets can avoid contact with and damage from the frame. However, under high forces, the four layered portion of the commissures can splay apart about a longitudinal axis adjacent to the window frame <NUM>, with each first portion <NUM> folding out against the respective second portion <NUM>. For example, this can occur when the prosthetic valve <NUM> is compressed and mounted onto a delivery shaft, allowing for a smaller crimped diameter. The four-layered portion of the commissures can also splay apart about the longitudinal axis when the balloon catheter is inflated during expansion of the prosthetic valve, which can relieve some of the pressure on the commissures caused by the balloon, reducing potential damage to the commissures during expansion.

After all three commissure tab assemblies are secured to respective window frame portions <NUM>, the lower edges of the leaflets <NUM> between the commissure tab assemblies can be sutured to the inner skirt <NUM>. For example, as shown in <FIG>, each leaflet <NUM> can be sutured to the inner skirt <NUM> along suture line <NUM> using, for example, Ethibond Excel® PET thread. The sutures can be in-and-out sutures extending through each leaflet <NUM>, the inner skirt <NUM>, and each reinforcing strip <NUM>. Each leaflet <NUM> and respective reinforcing strip <NUM> can be sewn separately to the inner skirt <NUM>. In this manner, the lower edges of the leaflets are secured to the frame <NUM> via the inner skirt <NUM>. As shown in <FIG>, the leaflets can be further secured to the skirt with blanket sutures <NUM> that extend through each reinforcing strip <NUM>, leaflet <NUM> and the inner skirt <NUM> while looping around the edges of the reinforcing strips <NUM> and leaflets <NUM>. The blanket sutures <NUM> can be formed from PTFE suture material. <FIG> shows a side view of the frame <NUM>, leaflet structure <NUM> and the inner skirt <NUM> after securing the leaflet structure <NUM> and the inner skirt <NUM> to the frame <NUM> and the leaflet structure <NUM> to the inner skirt <NUM>.

<FIG> show another embodiment of an outer skirt or sealing member <NUM> that can be incorporated in a prosthetic valve, such as valve <NUM>. <FIG> shows a flattened view of the outer skirt <NUM> prior to its attachment to a prosthetic heart valve. <FIG> shows a view of the outer skirt <NUM> in a cylindrical configuration prior to its attachment to a prosthetic heart valve.

Referring to <FIG>, the outer skirt <NUM> can comprise an upper edge portion <NUM>, a lower edge portion <NUM> and an intermediate portion <NUM> disposed between the upper edge portion <NUM> and the lower edge portion <NUM>. The intermediate portion <NUM> can comprise a plurality of vertical slits, cuts, or openings <NUM> cut or otherwise formed in the outer skirt <NUM> at circumferentially spaced apart locations. Each adjacent pair of slits <NUM> defines a vertical strip <NUM> (also referred to as a skirt segment) therebetween such that there are a plurality of such strips <NUM>, each extending lengthwise along the length of the outer skirt <NUM> from the upper edge portion <NUM> to the lower edge portion <NUM>. Each strip <NUM> in the illustrated embodiment defines opposing longitudinally extending edge portions <NUM> adjacent to respective slits <NUM>.

The outer skirt <NUM> can be formed from synthetic materials, including woven fabrics, non-woven fabrics, or non-fabric materials (e.g., foams, sheets), formed from any of various suitable biocompatible polymer, such as PET, PTFE, ePTFE, polyurethane, polyester; natural tissue (pericardium); and/or other suitable materials configured to restrict and/or prevent blood-flow therethrough. Alternatively, the outer skirt <NUM> can be formed from an elastic material. The slits <NUM> can be laser cut or formed by any other suitable means. The outer skirt <NUM> can be secured to the frame of a prosthetic heart valve as discussed below in connection with <FIG>.

The slits <NUM> in the illustrated embodiment are straight, and therefore define strips <NUM> that are rectangular. However, in other embodiments, the slits <NUM> can have various other shapes, including curved portions, so as to define strips <NUM> of various shapes. For example, the slits <NUM> can have an undulating or sinusoidal shape so as to define strips <NUM> having longitudinal side edges of the same shape. Further, as shown in the illustrated embodiment, the slits <NUM> terminate short of the upper and lower edges of the skirt. As such, the strips <NUM> are connected to each other at their upper and lower ends by the upper edge portion <NUM> and the lower edge portion <NUM> of the skirt. In other embodiments, one or more of the slits <NUM> can extend all the way to the very upper or lower edge of the skirt such that a strip <NUM> is not connected to an adjacent strip where the slit <NUM> extends all the way to an upper or lower edge of the skirt.

<FIG> show the outer skirt <NUM> of <FIG> mounted on the outside of a frame <NUM>. <FIG> shows an enlarged view of a portion of the frame <NUM> and the outer skirt <NUM>. The frame <NUM> and the outer skirt <NUM> can be part of a prosthetic heart valve similar to prosthetic heart valve <NUM> that can include a valvular structure similar to valvular structure <NUM> and an inner skirt similar to inner skirt <NUM>, as best shown in <FIG>. For illustrative purposes, <FIG> only show the frame <NUM> and the outer skirt <NUM>.

As previously described and as best shown in <FIG>, the frame <NUM> comprises axially extending struts <NUM> between rows I and II of angled struts <NUM>, <NUM>. The first row of struts I, the second row of struts II and the axially extending struts <NUM> define a plurality of cells defining openings <NUM>. Prior to attachment to the frame <NUM>, the outer skirt <NUM> can be arranged around the outer surface of the frame <NUM> such that each slit <NUM> is adjacent to an axially extending strut <NUM> and such that each strip <NUM> substantially covers one of the cell openings <NUM>. The upper and lower edge portions <NUM>, <NUM> of the outer skirt <NUM> can be secured to the frame <NUM> using suitable techniques and/or mechanisms, including sutures, an adhesive and/or ultrasonic welding. In particular embodiments, for example, the entire extent of the lower edge portion <NUM> can be sutured to the angled struts <NUM> of row I of the frame <NUM>, while the upper edge portion <NUM> can be sutured at the junctions formed by the intersection of struts <NUM> with struts <NUM>. In other embodiments, the entire extent of the upper edge portion <NUM> can be sutured to struts <NUM> or struts <NUM>. In some embodiments, the upper edge portion <NUM> can have an undulating or scalloped shaped, such as shown for the skirt <NUM> and can be sutured to the frame <NUM> as shown in <FIG>.

In particular embodiments, the height H of the outer skirt <NUM> in the axial direction can be greater than the axial distance between the attachment locations of the upper and lower edge portions <NUM>, <NUM> of the outer skirt <NUM> when the frame <NUM> is in a radially collapsed configuration. In this manner, radial expansion of the frame <NUM> results in foreshortening of the frame <NUM> between the attachment locations of the skirt <NUM>, creating slack in the skirt <NUM> between the attachments locations and allowing the strips <NUM> to move outwardly from the frame <NUM>. In the illustrated example, the axial length of the outer skirt <NUM> is equal to the length of a strut <NUM> plus the length of a strut <NUM> plus the length of a strut <NUM> plus the length of a strut <NUM> of frame <NUM>. In alternative embodiments, the outer skirt <NUM> can have different heights H, depending on the particular application.

In addition to the upper and lower end portions <NUM>, <NUM> being secured to the frame <NUM>, at least one of the longitudinal edge portions <NUM> of each of the plurality of strips <NUM> can be secured to the frame <NUM> and/or to other strips so as to produce circumferential and/or twisting movement of the strips <NUM> upon radial expansion of the frame <NUM>. In the illustrated example, the strips <NUM> are secured to the frame <NUM> with tethers <NUM>, which can be, for example, sutures, flexible wires, filaments, or similar materials. Alternatively, the strips <NUM> can be secured to the frame <NUM> with adhesive and/or ultrasonic welding in addition to or in lieu of sutures.

In the illustrated embodiment, for each one of the plurality of strips <NUM>, an edge portion 212a can be secured to a strut <NUM> with a tether <NUM> having one end 214a tied off or knotted around the strut <NUM> and the other end 214b tied off to the strip <NUM>. Desirably, the edge 212a of the strip <NUM> is secured to the strut <NUM> that is closest to the unsecured edge 212b of the same strip such that the tether <NUM> extends across the width of the strip <NUM> and the unsecured edge 212b. As such, when the frame <NUM> is in a radially collapsed configuration, the axially extending struts <NUM> are closer together and the strips <NUM> extend in a substantially straight line between the upper and lower edges <NUM>, <NUM> of the skirt <NUM>. However, when the frame <NUM> expands to a radially expanded configuration, the axially extending struts <NUM> move away from each other, pulling the secured edge 212a of each strip <NUM> toward its unsecured edge 212b, thereby decreasing the width of the strip <NUM> between its upper and lower ends (the width of the strip extending in the circumferential direction) and forming longitudinal folds in the strip <NUM>. In this manner, the strips <NUM> form rib-like projections that can also extend radially outward from frame <NUM> due to the foreshortening of the frame <NUM> as it expands radially.

In the illustrated embodiment, the tethers <NUM> are positioned radially outside of the skirt <NUM>. In some embodiments, the tethers <NUM> can be positioned radially inside of the skirt <NUM>. In other embodiments, some of the tethers <NUM> can be positioned outside of the skirt <NUM> while other tethers <NUM> are positioned inside of the skirt <NUM>. When the prosthetic valve (e.g., a valve <NUM> with outer skirt <NUM>) is implanted in a native annulus, the projections formed by the strips <NUM> can contact and form a seal against the surrounding tissue to prevent or minimize perivalvular leakage.

<FIG> show another embodiment comprising a frame <NUM> and an outer skirt <NUM>. The embodiment of <FIG> is the same as the embodiment of <FIG> except for the manner in which the skirt <NUM> is secured to the frame <NUM>. As noted above with respect to the embodiment of <FIG>, the embodiment of <FIG> can include a valvular structure, such as valvular structure <NUM>, and an inner skirt, such as inner skirt <NUM>, as best shown in <FIG>, to form a prosthetic heart valve. For illustrative purposes, <FIG> only show the frame <NUM> and the outer skirt <NUM>.

Referring to <FIG>, the upper and lower edge portions <NUM>, <NUM> of the outer skirt <NUM> can be secured to the frame <NUM> as previously described herein. A first longitudinal edge portion 212a of each strip <NUM> can be secured to a strut 34a that is adjacent to a second longitudinal edge portion 212b of the same strip <NUM> by a first tether <NUM>. The first tether <NUM> extends across the width of the strip <NUM> and has a first end 214a tied off or knotted around the strut 34a and a second end 214b that is secured to the edge portion 212a. The second longitudinal edge portion 212b is secured to a strut 34b that is adjacent the first edge portion 212a by a second tether <NUM>. The second tether <NUM> extends across the width of the strip and has a first end 216a tied off or knotted around the strut 34b and a second end 216b secured to the second edge portion 212b.

The tethers <NUM>, <NUM> desirably are on opposite sides of the skirt <NUM>. As shown in the illustrated embodiment, the first tether <NUM> is positioned radially outside of the skirt <NUM>, while the second tether <NUM> is positioned radially inside of the skirt <NUM>. As such, when the frame <NUM> expands to a radially expanded configuration (causing struts 34a, 34b to move away from each other), the first edge portion 212a is pulled toward the second edge portion 212b by the first tether <NUM> and the second edge portion 212b is pulled toward the first edge portion 212a. The pulling of the tethers <NUM>, <NUM> causes the width of the strip <NUM> to decrease and form longitudinal folds, and also causes the strip <NUM> to become slightly twisted or rotated by virtue of the tethers <NUM>, <NUM> being on opposite sides of the outer skirt <NUM>. As previously described, the strips <NUM> can also project radially away from the frame <NUM> due to frame foreshortening, forming rib-like projections that can help seal the prosthetic valve against the native annulus. In alternative embodiments, the tethers <NUM>, <NUM> can be on the same side of the skirt <NUM> (i.e., both tethers <NUM>, <NUM> can be positioned radially outside the skirt <NUM> or radially inside the skirt <NUM>), in which case the strip <NUM> assumes a similar shape upon expansion of the frame but without twisting of the opposing edge portions 212a, 212b.

<FIG> show another embodiment comprising a frame <NUM> and an outer skirt <NUM>. The embodiment of <FIG> is the same as the embodiment of <FIG> except for the manner in which the skirt <NUM> is secured to the frame <NUM>. As noted above with respect to the embodiment of <FIG>, the embodiment of <FIG> can include a valvular structure, such as valvular structure <NUM>, and an inner skirt, such as inner skirt <NUM>, as best shown in <FIG>, to form a prosthetic heart valve. For illustrative purposes, <FIG> only show the frame <NUM> and the outer skirt <NUM>. In this embodiment, the skirt segments are coupled to each other with tethers (rather than to struts of the frame) to produce movement of the skirt segments upon radial expansion of the frame.

Referring to <FIG>, the upper and lower edge portions <NUM>, <NUM> of the outer skirt <NUM> can be secured to the frame <NUM> as previously described herein. The outer skirt <NUM> comprises a plurality of strips 210a and 210b alternately positioned around an outer surface of the frame <NUM>, which are similar to the strips <NUM> of <FIG> except for how they are secured to the frame <NUM>. A first longitudinal edge portion 212a of each strip 210a can be secured to a longitudinal edge portion 212c of an adjacent strip 210b by a first tether <NUM>. The first tether <NUM> can extend across the width of strips 210a and 210b and can have a first end 218a secured to the edge portion 212c and a second end 218b secured to the edge portion 212a. A second longitudinal edge portion 212b of each strip 210a can be secured to a longitudinal edge portion 212d of an adjacent strip 210b on the other side of the strip 210a by a second tether <NUM>. The second tether <NUM> can extend across the width of strips 210a and 210b and can have a first end 220a secured to the edge portion 212b and a second end 220b secured to the edge portion 212d. In this manner, each strip 210a is coupled to two strips 210b on opposite sides of the strip 210a by tethers <NUM>, <NUM>. Each strip 210b can be coupled to two strips 210a in the same manner.

The tethers <NUM>, <NUM> desirably are on opposite sides of the skirt <NUM>. As shown in the illustrated embodiment, the first tether <NUM> is positioned radially inside of the skirt <NUM>, while the second tether <NUM> is positioned radially outside of the skirt <NUM>. As such, when the frame <NUM> expands to a radially expanded configuration, the edge portions 212a, 212c of strips 210a, 210b, respectively, are pulled inwardly towards each other and the edge portions 212b, 212d of strips 210a, 210b, respectively, are pulled outwardly towards each other. The pulling of strips 210a, 210b causes the width of the strips 210a, 210b to decrease and form longitudinal folds, and also causes the strips 210a, 210b to become slightly twisted or rotated by virtue of the tethers <NUM>, <NUM> being on opposite sides of the outer skirt <NUM>. As previously described, the strips 210a, 210b can also project radially away from the frame <NUM> due to frame foreshortening, forming rib-like projections that can help seal the prosthetic valve against the native annulus. In alternative embodiments, the tethers <NUM>, <NUM> can be on the same side of the skirt <NUM> (i.e., both tethers <NUM>, <NUM> can be positioned radially outside the skirt <NUM> or radially inside the skirt <NUM>), in which case the strips 210a, 210b assume a similar shape upon expansion of the frame but without twisting of the opposing edge portions 212a, 212b, 212c, 212d.

In the embodiment of <FIG>, each edge portion of a strip is coupled to the farthest edge portion of an adjacent strip. In alternative embodiments, each edge portion of a strip can be coupled to the closer edge portion of an adjacent strip. For example, edge portion 212a of a strip 210a can be coupled to edge portion 212d of one strip 210b by tether <NUM>, while edge portion 212b can be coupled to edge portion 212c by tether <NUM> of another strip 210b. In still other embodiments, the different techniques for coupling the skirt strips to the frame struts and to each other described above can be combined in a single prosthetic valve. For example, a skirt <NUM> can have some strips coupled to frame struts in the manner shown in <FIG>, some strips coupled to frame struts in the manner shown in <FIG>, and some strips coupled to each other in the manner shown in <FIG> and/or described above.

In alternative embodiments, instead of having a single skirt mounted on the outside of the frame, the outer sealing member can comprise a plurality of discrete sealing segments positioned side-by-side around the circumference of the frame. For example, instead of cutting slits <NUM> in the skirt <NUM>, the skirt <NUM> can be cut along cut lines extending from the lower edge to the upper edge at the locations of slits <NUM> in <FIG> to form a plurality of rectangular sealing segments. Each discrete sealing segment can be secured to the frame at its upper and lower edge portions. Each discrete sealing segment can be coupled to the frame and/or to one or more other sealing segments by one or more tethers using any of the configurations described above.

The prosthetic valve <NUM> can be configured for and mounted on a suitable delivery apparatus for implantation in a patient. Several catheter-based delivery apparatuses can be used; a non-limiting example of a suitable catheter-based delivery apparatus includes that disclosed in <CIT> and <CIT>.

In one example, to implant a plastically-expandable prosthetic valve <NUM> within a patient, the prosthetic valve <NUM>, including the frame <NUM> and the outer skirt <NUM> can be crimped on an elongated shaft <NUM> of a delivery apparatus, as best shown in <FIG>. The prosthetic valve, together with the delivery apparatus, can form a delivery assembly for implanting the prosthetic valve <NUM> in a patient's body. The shaft <NUM> comprises an inflatable balloon <NUM> for expanding the prosthetic valve within the body. With the balloon <NUM> deflated, the prosthetic valve <NUM> can then be percutaneously delivered to a desired implantation location (e.g., a native aortic valve region). Once the prosthetic valve <NUM> is delivered to the implantation site (e.g., the native aortic valve) inside the body, the prosthetic valve <NUM> can be radially expanded to its functional state by inflating the balloon <NUM>.

Alternatively, a self-expanding prosthetic valve <NUM> can be crimped to a radially collapsed configuration and restrained in the collapsed configuration by inserting the prosthetic valve <NUM>, including the frame <NUM> and the outer skirt <NUM> into a sheath or equivalent mechanism of a delivery catheter. The prosthetic valve <NUM> can then be percutaneously delivered to a desired implantation location. Once inside the body, the prosthetic valve <NUM> can be advanced from the delivery sheath, which allows the prosthetic valve <NUM> to expand to its functional state.

<FIG> and <FIG>show various implantation positions for a prosthetic heart valve <NUM> having outer skirt <NUM> in place of outer skirt <NUM> as discussed above in connection with <FIG>, including implantation within a dock or anchor placed inside the patient's body prior to valve implantation. In the illustrated embodiments of <FIG>, the outer skirt <NUM> is configured in a manner described in connection with <FIG>. In other embodiments, the outer skirt <NUM> of <FIG> can be configured in a manner described in connection with <FIG> or in a manner described in connection with <FIG>. <FIG> shows the prosthetic heart valve <NUM> implanted in the native aortic valve of a patient.

<FIG> shows the prosthetic heart valve <NUM> implanted in the pulmonary artery of a patient for replacing or enhancing the function of a diseased pulmonary valve. Due to the variations in the size and shape of the native pulmonary valve and the pulmonary artery, the prosthetic valve <NUM> can be implanted within a radially expandable outer docking device <NUM>. The docking device <NUM> can comprise a radially expandable and compressible annular stent <NUM> and a sealing member <NUM> that covers all or a portion of the stent and can extend across the inner surface and/or outer surface of the stent. The docking device <NUM> is configured to engage the inner wall of the pulmonary artery and can accommodate variations in patient anatomy. The docking device <NUM> also can compensate for the expanded prosthetic heart valve <NUM> being much smaller than vessel in which it is placed. The docking device <NUM> also can be used to support a prosthetic valve in other areas of the patient's anatomy, such as, the inferior vena cava, superior vena cava, or the aorta. Further details of the docking device <NUM> and methods for implanting the docking device and a prosthetic valve are disclosed, for example, in co-pending <CIT>.

<FIG> shows the prosthetic heart valve <NUM> implanted in the native mitral valve of a patient using a docking device in the form of a helical anchor <NUM>. The helical anchor <NUM> can include one or more coils <NUM> deployed in left atrium and one or more coils <NUM> deployed in the left ventricle and radially outside of the native mitral valve leaflets <NUM>. When the prosthetic valve <NUM> is deployed within the native valve, the native leaflets are compressed or pinched between the prosthetic valve <NUM> and the anchor <NUM> to retain the prosthetic valve in place. Further details of the helical anchor <NUM> and methods for implanting the anchor and a prosthetic valve are disclosed, for example, in co-pending <CIT>.

<FIG> show a docking device <NUM> for a prosthetic heart valve, according to another embodiment. The docking device <NUM> can include a radially expandable and compressible frame <NUM> having an outer portion <NUM>, an inner portion <NUM> disposed coaxially within one end portion of the outer portion <NUM>, and a curved transition portion <NUM> extending between and connecting the inner portion <NUM> and the outer portion <NUM>. The docking device <NUM> can further include a sealing member <NUM> extending over the inner surface of the inner portion <NUM>, a portion of the outer surface of the outer portion <NUM> adjacent the inner portion <NUM>, and the transition portion <NUM>.

<FIG> shows the docking device <NUM> implanted in a vessel <NUM>, which can be, for example, the inferior vena cava, superior vena cava, or the ascending aorta. As shown, a prosthetic valve <NUM> can be deployed within the inner portion <NUM> of the docking device <NUM>. Similar to the docking device <NUM>, the docking device <NUM> can compensate for the expanded prosthetic heart valve <NUM> being much smaller than vessel in which it is placed. The docking device <NUM> is particularly suited for implanting a prosthetic valve in the inferior vena cava for replacing or enhancing the function of the native tricuspid valve. Further details of the docking device <NUM> and methods for implanting the docking device and a prosthetic valve are disclosed, for example, in co-pending <CIT>.

It should be understood that the disclosed valves can be implanted in any of the native annuluses of the heart (e.g., the pulmonary, mitral, and tricuspid annuluses), and can be used with any of various approaches (e.g., retrograde, antegrade, transseptal, transventricular, transatrial, etc.). The disclosed prostheses can also be implanted in other lumens of the body.

For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The disclosed methods, apparatus, and systems should not be construed as being limiting in any way.

As used in this application and in the claims, the singular forms "a," "an," and "the" include the plural forms unless the context clearly dictates otherwise. Additionally, the term "includes" means "comprises.

As used herein, the term "and/or" used between the last two of a list of elements means any one or more of the listed elements. For example, the phrase "A, B, and/or C" means "A", "B", "C", "A and B", "A and C", "B and C", or "A, B, and C".

As used herein, the term "proximal" refers to a position, direction, or portion of a device that is closer to the user and further away from the implantation site. As used herein, the term "distal" refers to a position, direction, or portion of a device that is further away from the user and closer to the implantation site. Thus, for example, proximal motion of a device is motion of the device toward the user, while distal motion of the device is motion of the device away from the user. The terms "longitudinal" and "axial" refer to an axis extending in the proximal and distal directions, unless otherwise expressly defined.

As used herein, the terms "coupled" and "associated" generally mean physically coupled or linked and does not exclude the presence of intermediate elements between the coupled or associated items absent specific contrary language.

As used herein, operations that occur "simultaneously" or "concurrently" occur generally at the same time as one another, although delays in the occurrence of one operation relative to the other due to, for example, spacing, play or backlash between components in a mechanical linkage such as threads, gears, etc., are expressly within the scope of the above terms, absent specific contrary language.

Claim 1:
An implantable prosthetic valve (<NUM>) comprising:
an annular frame (<NUM>) comprising an inflow end and an outflow end and being radially collapsible and expandable between a radially collapsed configuration and a radially expanded configuration, the frame (<NUM>) defining an axial direction extending from the inflow end to the outflow end;
a leaflet structure (<NUM>) positioned within the frame (<NUM>) and secured thereto; and
an annular outer skirt (<NUM>) positioned around an outer surface of the frame (<NUM>), wherein the outer skirt (<NUM>) comprises:
an inflow edge portion (<NUM>) secured to the frame (<NUM>) at a first location;
an outflow edge portion (<NUM>) secured to the frame (<NUM>) at a second location;
an intermediate portion (<NUM>) between the inflow edge portion (<NUM>) and the outflow edge portion (<NUM>), wherein the intermediate portion (<NUM>) comprises a plurality of circumferentially spaced, axially extending slits (<NUM>) that define a plurality of skirt segments (<NUM>) between each pair of slits (<NUM>), wherein each skirt segment (<NUM>) comprises first and second opposing edge portions (<NUM>);
wherein at least one of the first and second opposing edge portions (<NUM>) of each of the plurality of skirt segments (<NUM>) are secured to the frame (<NUM>) and/or to other skirt segments (<NUM>) so as to produce circumferential and/or twisting movement of the skirt segments (<NUM>) upon radial expansion of the frame (<NUM>).