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. For example, <CIT>,<CIT>,<CIT>, and<CIT> describe exemplary collapsible and expandable transcatheter prosthetic heart valves.

<CIT> relates to an implantable prosthetic valve comprising an annular frame. The annular frame comprises 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 further defines an axial direction extending from the inflow end to the outflow end. A leaflet structure is positioned within the frame and secured thereto. An annular outer skirt is positioned around an outer surface of the frame. The outer skirt comprises an inflow edge secured to the frame at a first location, an outflow edge comprising a plurality of alternating projections and notches, the projections being secured to the frame at a second location, and the notches being not directly secured to the frame. An intermediate portion between the inflow edge and the outflow edge comprises a plurality of openings.

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 subject.

The present invention relates to an implantable prosthetic valve as defined in appended claim <NUM> and an assembly for implanting a prosthetic heat valve as defined in appended claim <NUM>.

Embodiments not covered by the claims are illustrative. 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 subject.

In one representative embodiment, an implantable prosthetic heart valve comprises an annular frame comprising an inflow end and an outflow end and being radially collapsible and expandable between a radially collapsed configuration and a radially expanded configuration, and a leaflet structure positioned within the frame and secured thereto. The prosthetic heart valve further comprises an annular inner skirt positioned around an inner surface of the frame, wherein the inner skirt comprises an outflow edge portion secured to the frame and an inflow edge portion secured to the frame. According to the invention, the inflow edge portion wraps around the inflow end of the frame and extends at least partially along an outer surface of the frame. The prosthetic heart valve can also have an outer skirt positioned around the outer surface of the frame, wherein the outer skirt comprises an outflow edge portion secured to the frame and an inwardly folded inflow edge portion that is secured to the inflow edge portion of the inner skirt.

In some embodiments, the inflow edge portion of the inner skirt can be secured to the frame at discrete, spaced-apart locations. In such embodiments, the inflow edge portion of the outer skirt can be secured to the inflow edge portion of the inner skirt only at locations on the inflow edge portion of the inner skirt that are secured to the frame.

In some embodiments, the frame can further comprise a plurality of struts forming a plurality of circumferentially spaced apices at the inflow end of the frame, and the inflow edge portion of the inner skirt can be secured to the frame only at the apices.

In some embodiments, the inflow edge portion of the outer skirt can be secured to the inflow edge portion of the inner skirt only at locations on the inflow edge portion of the inner skirt that are secured to the apices of the frame. In some embodiments, the inflow edge portion of the inner skirt can be secured to the frame with discrete, spaced-apart sutures.

In some embodiments, the outflow edge portion of the outer skirt can comprise a plurality of alternating projections and notches, and the projections can be secured to the frame and the notches can be not directly secured to the frame.

In some embodiments, the outer skirt can further comprise an intermediate portion between the inflow edge portion and the outflow edge portion and the intermediate portion can comprise a plurality of openings. In such embodiments, the openings can be aligned with the projections.

In some embodiments, the inflow edge portion of the outer skirt can comprise a plurality of overlapping portions that are angularly aligned with the openings, wherein the overlapping portions are folded inwardly towards the outflow end of the frame, and wherein the overlapping portions are secured to the inflow edge portion of the inner skirt. In such embodiments, the overlapping portions can be secured to the inflow edge portion of the inner skirt only at locations on the inflow edge portion of the inner skirt that are secured to the frame. In such embodiments, the overlapping portions can be folded such that each of the overlapping portions is radially aligned with a corresponding one of the openings when the overlapping portions are secured to the inner skirt.

In some embodiments, the outer skirt can be secured to the inner skirt by sutures. In some embodiments, the inner and outer skirts can be configured such that when the prosthetic valve is implanted, antegrade blood can flow through a space between the inflow edge portion of the inner skirt and the inflow edge portion of the outer skirt. In some embodiments, the inflow edge portion of the inner skirt can be loosely stitched to the inflow edge portion of the outer skirt.

In another representative embodiment, an assembly for implanting a prosthetic heart valve in a patient's body is provided. The assembly can comprise a delivery apparatus comprising an elongate shaft, and a prosthetic heart valve mounted on the shaft in a radially collapsed configuration for delivery into the body.

As an example application not belonging to the invention, a method of implanting a prosthetic heart valve in a patient's body is provided. The method can comprise radially compressing the prosthetic heart valve to a radially compressed configuration, coupling the prosthetic heart valve to the distal end of a delivery apparatus, inserting the distal end portion of the delivery apparatus and the prosthetic heart valve into a patient's body, positioning the prosthetic heart valve adjacent a native valve of the patient's heart, and radially expanding the prosthetic heart valve so that it engages the native valve. The prosthetic heart valve can comprise an annular frame comprising an inflow end and an outflow end and being radially collapsible and expandable between a radially collapsed configuration and a radially expanded configuration, a leaflet structure positioned within the frame and secured thereto, an annular inner skirt positioned around an inner surface of the frame, wherein the inner skirt comprises an outflow edge portion secured to the frame and an inflow edge portion that wraps around the inflow end of the frame and extends at least partially along an outer surface of the frame, the inflow edge portion being secured to the frame, and an outer skirt positioned around the outer surface of the frame, wherein the outer skirt comprises an outflow edge portion secured to the frame and an inwardly folded inflow edge portion that is secured to the inflow edge portion of the inner skirt.

In some examples, the outer skirt can engage the native valve and antegrade blood can flow through the space between the inflow edge portion of the outer skirt and the inflow edge portion of an inner skirt and enter space between the frame and the outer skirt to help seal the outer skirt against the native valve.

In some examples, the inflow edge portion of the inner skirt can be secured to the frame at discrete, space-apart locations. In such embodiments, the inflow edge portion of the outer skirt can be secured to the inflow edge portion of the inner skirt only at locations on the inflow edge portion of the inner skirt that are secured to the frame.

<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>.

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 is 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 an inner portion <NUM> folded against the inner surface of the leaflet and an outer portion <NUM> folded against the connector <NUM>. The outer 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 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 inner portion <NUM> folding out against the respective outer 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> shows a flattened view of the outer skirt <NUM> prior to its attachment to the frame <NUM>. The outer skirt <NUM> can be laser cut or otherwise formed from a strong, durable material such as PET or various other suitable synthetic or natural materials configured to restrict and/or prevent blood-flow therethrough. The outer skirt <NUM> can comprise a substantially straight lower edge <NUM> and an upper edge portion <NUM> defining a plurality of alternating projections <NUM> and notches <NUM>, or castellations. The outer skirt <NUM> can also comprise a plurality of openings <NUM> (e.g., <NUM> in the illustrated embodiment) disposed on an intermediate portion <NUM> (i.e., the portion between the lower edge <NUM> and the upper edge portion <NUM>) of the outer skirt <NUM>. The openings <NUM> are spaced from the lower edge <NUM> and the upper edge portion <NUM> such that the material of the outer skirt <NUM> separates the openings <NUM> from the lower edge <NUM> and the upper edge portion <NUM>.

As best shown in <FIG>, in some embodiments, a lower edge portion <NUM> of the outer skirt <NUM> can be wrapped around the inflow end <NUM> of the frame <NUM>, and the lower edge <NUM> of the outer skirt <NUM> can be attached to the lower edge <NUM> of the inner skirt <NUM> and/or the frame <NUM> at the inflow end of the prosthetic valve <NUM>. In some embodiments, the outer skirt <NUM> can be attached to the inner skirt <NUM>, for example, with sutures or a suitable adhesive.

In lieu of or in addition to sutures, the outer skirt <NUM> can be attached to the inner skirt <NUM>, for example, by ultrasonic welding. Ultrasonic welding can provide several significant advantages. For example, ultrasonic welding can be relatively less time consuming and less expensive compared to suturing, while also providing improved strength.

As shown in <FIG>, each projection <NUM> of the outer skirt <NUM> can be attached to the third row III of struts <NUM> (<FIG>) of the frame <NUM>. The projections <NUM> can, for example, be wrapped over respective struts <NUM> of row III and secured with sutures <NUM>.

As can be seen in <FIG>, the outer skirt <NUM> is secured to the frame <NUM> such that when the frame is in its expanded configuration (e.g., when deployed in a subject), there is excess material between the lower edge <NUM> and the upper edge portion <NUM> that does not lie flat against the outer surface of the frame <NUM>. The outer skirt <NUM> can be secured directly to frame <NUM> and/or indirectly to frame <NUM>, for example, by securing the outer skirt <NUM> to the inner skirt <NUM>, which is directly secured to the frame <NUM>. In the expanded configuration of the prosthetic valve, the distance between the upper and lower attachment points of the outer skirt <NUM> decreases (foreshortens), resulting in radial expansion of the outer skirt <NUM>. Additionally, the excess material between the lower and upper edges of the outer skirt <NUM> allows the frame <NUM> to elongate axially when crimped without any resistance from the outer skirt <NUM>.

The outer skirt <NUM> can comprise an axial length or height Hs. In some embodiments, Hs is the height of the outer skirt <NUM>, less the lower edge portion <NUM> that is wrapped around the inflow end <NUM> of the frame <NUM>, as best shown in <FIG>, and <FIG>. In some embodiments, the height Hs can be substantially the same as the axial length between the upper attachment point of the outer skirt <NUM> to the frame <NUM> and the inflow end <NUM> of the frame <NUM> when the frame <NUM> is fully crimped. In such embodiments, when the frame <NUM> is fully crimped, the outer skirt <NUM> can lie flat against the outer surface of the frame <NUM>. In other embodiments, the height Hs of the outer skirt <NUM> can exceed the axial length between the upper attachment point of the outer skirt <NUM> to the frame <NUM> and the inflow end <NUM> of the frame <NUM> when the frame <NUM> is fully crimped. In such embodiments, the outer skirt <NUM> can comprise a plurality of creases <NUM> (e.g., twelve in the illustrated embodiment).

As best shown in <FIG>, the creases <NUM> can extend axially from the lower edge <NUM> toward the intermediate portion <NUM> of the outer skirt <NUM>. The creases <NUM> can be aligned circumferentially with respective projections <NUM>, and the outer skirt <NUM> can be oriented with respect to the frame <NUM> such that the creases <NUM> are circumferentially aligned between a respective pair of apices 22a (<FIG>) that are formed by the struts <NUM> at the inflow end <NUM> of the frame <NUM>. For example, the creases <NUM> can be circumferentially aligned along a respective vertical line <NUM> (<FIG> and <FIG>) that is parallel to the longitudinal axis of the frame <NUM> and bisects the frame <NUM> at a location equidistant from each apex 22a of a respective pair of apices 22a. In this manner, the creases <NUM> can cause excess material of the outer skirt <NUM> to retract radially inwardly between the apices 22a and into the inflow end <NUM> of the frame <NUM> when the prosthetic valve <NUM> is crimped from the expanded configuration. As best shown in <FIG>, each crease <NUM> can be circumferentially aligned with a respective opening <NUM> and projection <NUM> along a respective line <NUM>.

Referring to <FIG>, in lieu of or in addition to the creases <NUM> (<FIG>), the outer skirt <NUM> can be attached and/or positioned relative to the frame <NUM> such that the lower edge <NUM> of the outer skirt <NUM> contacts the inflow end <NUM> of the frame <NUM> at locations (e.g., apices 22a) that are offset relative to locations (e.g., the junctions <NUM>) at which the upper edge portion <NUM> of the outer skirt <NUM> contacts the outflow end <NUM> of the frame <NUM>. Configuring the outer skirt <NUM> and the frame <NUM> in this manner can cause excess material of the outer skirt <NUM> to retract inwardly between the apices 22a of the frame <NUM> when the prosthetic valve <NUM> is crimped from the expanded configuration (e.g., <FIG>) to the collapsed configuration (e.g., <FIG>), as shown in <FIG>.

This configuration also spreads the deformed fabric of the collapsed outer skirt <NUM> over a relatively large distance, which reduces the amount of outer skirt material per cross sectional area and flattens the outer skirt <NUM> around the crimped frame <NUM>, thus reducing the crimped profile of the prosthetic heart valve <NUM>. Reducing the crimped profile of the prosthetic heart valve <NUM> can reduce the push force necessary to move the prosthetic heart valve <NUM> relative to a patient's vasculature or a delivery cylinder of a delivery apparatus. It can also reduce the compression force that is exerted upon the leaflets <NUM> to achieve a particular crimp profile, which can reduce and/or eliminate damage to the leaflets <NUM> caused by over compressing the leaflets <NUM> during crimping and/or delivery of the prosthetic heart valve <NUM> to an implantation location.

Retracting the excess material within the frame <NUM> below the leaflets <NUM> when the prosthetic valve <NUM> is crimped advantageously allows the prosthetic valve <NUM> to have a relatively large outer skirt <NUM>, which can significantly reduce perivalvular leakage, while minimizing the radial crimp profile of the prosthetic valve <NUM>. For example, the height Hs of the outer skirt <NUM> can be about <NUM> to about <NUM> or about <NUM> to about <NUM>, with about <NUM> being a specific example. The height Hf of the frame <NUM> in the radially expanded state can be about <NUM> to about <NUM> or about <NUM> to about <NUM>, with about <NUM> being a specific example. The outer skirt <NUM> can be sized such that a ratio Hs:Hf, where Hs (<FIG>) is the height of the outer skirt <NUM>, and Hf (<FIG>) is the height of the frame <NUM> in the expanded state, can be between about <NUM> to about <NUM>. In some embodiments, the ratio Hs:Hf can be between about <NUM> to about <NUM> or about <NUM> to about <NUM>. In one particular embodiment, the ratio Hs:Hf can be <NUM>.

Providing a relatively larger outer skirt <NUM> allows the prosthetic valve <NUM> to be positioned in a wider range of positions relative to the native annulus, while providing adequate perivalvular sealing. This improved range can make the prosthetic valve <NUM> easier to position during the implantation procedure. It also allows the prosthetic valve to adapt to greater variation in native annulus anatomy.

In addition, the creases <NUM> can assist the outer skirt <NUM> in collapsing in a predetermined, uniform manner when the prosthetic valve is crimped and allows the outer skirt <NUM> to expand to its functional state more quickly and consistently when deploying the prosthetic valve <NUM>, as further described below.

Each crease <NUM> can be formed, for example, by overlapping adjacent portions of the outer skirt <NUM> and securing them together. The creases can then be secured in the overlapped state, for example, by sutures, ultrasonic welding, and/or an adhesive. The creases <NUM> can be referred to as permanent creases in that the creases are retained when the prosthetic valve <NUM> is in a radially compressed state and a radially expanded state.

As best shown in <FIG>, the openings <NUM> can be laterally (circumferentially in <FIG>) spaced apart relative to adjacent openings <NUM> and be laterally (circumferentially in <FIG>) aligned with a respective projection <NUM>. The openings <NUM> can also be circumferentially aligned with respective creases <NUM>, as best shown in <FIG>. For example, the projections <NUM>, the openings <NUM>, and the creases <NUM> can be aligned along the respective vertical lines <NUM>, as best shown in <FIG>. Aligning the openings <NUM> and the creases <NUM> can, for example, allow blood to quickly enter, and thus expose much more surface area of the skirt material to blood. In addition, the overlapped portions of the outer skirt <NUM> can expand when the prosthetic valve is initially deployed, as further described below.

The openings <NUM> can comprise various shapes. For example, the openings <NUM> can comprise a tear-drop shape, as shown in the illustrated embodiment. In other embodiments, the openings can be circular, elliptical, rectangular, etc..

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

To implant a plastically-expandable prosthetic valve <NUM> within a patient, the prosthetic valve <NUM> including 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 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 to expand to its functional state.

<FIG> shows an exemplary embodiment of an outer skirt <NUM>. The outer skirt <NUM> can comprise a first end portion <NUM> (i.e., the upper end portion as depicted in <FIG>), a second end portion <NUM> (i.e., the lower end portion as depicted in <FIG>), and an intermediate portion <NUM> disposed between the first and second end portions <NUM>, <NUM>.

The first end portion <NUM> of the outer skirt <NUM> can include a plurality of alternating projections <NUM> and notches <NUM> and can also include a plurality of first openings <NUM>. The first end portion <NUM> can be configured similar to the projections <NUM>, the notches <NUM>, and the openings <NUM> of the outer skirt <NUM>. For example, the first openings <NUM> can be circumferentially aligned with the projections <NUM> and circumferentially offset relative to the notches <NUM>. The first end portion <NUM> can be attached to an inner skirt and/or frame of a prosthetic heart valve, as further described below.

The first openings <NUM> can comprise various sizes and/or shapes. For example, as shown in <FIG>, the first openings <NUM> comprise a "tear-drop" shape. In other embodiments, the first openings <NUM> can be larger (e.g., elongate) or smaller and can comprise various other shapes (e.g., circular, rectangular, or ovular) than those shown in the illustrated embodiment.

The first end portion <NUM> of the outer skirt <NUM> can comprise first outer diameter. In some embodiments, the first, outer diameter of the first end portion <NUM> is at least substantially similar to a second, outer diameter of the second end portion <NUM> and smaller than a third, outer diameter of the intermediate portion <NUM>. In other embodiments, the first diameter of the first end portion <NUM> can be smaller than the second diameter of the second end portion <NUM> and the third diameter of the intermediate portion <NUM>. In yet other embodiments, the first diameter of the first end portion <NUM> can be larger than the second diameter of the second end portion <NUM> and can be smaller than the third diameter of the intermediate portion <NUM>.

The second end portion <NUM> of the outer skirt <NUM> can comprise a substantially straight lower edge <NUM>. The second end portion <NUM> can be attached to an inner skirt and/or frame of a prosthetic heart valve, as further described below. The second diameter of the second end portion can be smaller than the third diameter of the intermediate portion <NUM>.

The intermediate portion <NUM> of the outer skirt <NUM> can comprise a radially outwardly facing surface <NUM>. As shown, in some embodiments, the surface <NUM> can be relatively flat. In other embodiments, the surface <NUM> can be relatively tapered, from the first end portion <NUM> to the second end portion <NUM>, or vice versa. In yet other embodiments, the surface <NUM> can be relatively curved or rounded.

In some embodiments, the surface <NUM> of the intermediate portion <NUM> can comprise a plurality of second openings <NUM>. The second openings <NUM> can be spaced apart relative to each other, circumferentially aligned with the notches <NUM> of the first end portion <NUM>, and circumferentially offset relative to the first openings <NUM> and the projections <NUM> of the first end portion <NUM>. The second openings <NUM> can comprise various shapes and/or sizes, including diamond-shaped (as shown in <FIG>), circular, rectangular, ovular, etc. In alternative embodiments, the surface <NUM> can be formed without the second openings <NUM>.

The intermediate portion <NUM> can also comprise first and second transition sections <NUM>, <NUM> separated relative to each other by the surface <NUM> and disposed adjacent to the first and second end portions <NUM>, <NUM>, respectively. In some embodiments, the transition sections <NUM>, <NUM> can be at least substantially perpendicular to the surface <NUM>. In such embodiments, the outer diameter of the outer skirt <NUM> abruptly transitions from the respective first and second diameters of the first and second end portions <NUM>, <NUM> to the third diameter of the intermediate portion <NUM> in a step- or flange-like manner. In other embodiments, the transition sections <NUM>, <NUM> can be angled between the respective end portions <NUM>, <NUM> and the surface <NUM> such that the outer diameter of the outer skirt <NUM> tapers from the respective first and second diameters of the end portions <NUM>, <NUM> to the third diameter of the intermediate portion <NUM>.

The outer skirt <NUM> can be coupled to a frame and/or an inner skirt of a prosthetic heart valve similar to the manner in which the outer skirt <NUM> is coupled to the frame <NUM> and/or the inner skirt <NUM> of the prosthetic heart valve <NUM>. For example, the outer skirt <NUM> can be attached to a frame and/or inner skirt of a prosthetic heart valve by sutures and/or ultrasonic welding.

The outer skirt <NUM> can be formed of materials such as PET, PTFE, ePTFE, polyurethane, polyester, and/or other suitable materials configured to restrict and/or prevent blood-flow therethrough. In some embodiments, the outer skirt <NUM> can be formed from a generally flat strip (e.g., similar to the outer skirt <NUM> as shown in <FIG>) and formed into a tube by welding the ends together, as shown in <FIG>. In other embodiments, the outer skirt <NUM> can be formed by weaving the outer skirt <NUM> into a tubular shape. The intermediate portion <NUM> can be formed, for example, by shape-setting the material to a desired configuration (e.g., as shown in <FIG>).

The outer skirt <NUM> can be configured to be radially compressed to a delivery configuration and to radially expand from the delivery configuration to a function configuration, in a manner similar to the outer skirt <NUM>. In some embodiments, the outer skirt <NUM> can be self-expandable, such as by including Nitinol threads in the outer skirt <NUM>.

In this manner, the outer skirt <NUM> in conjunction with the inner skirt <NUM> can reduce and/or eliminate perivalvular leakage between a frame of a prosthetic heart valve and a native annulus. As a result, the outer skirt <NUM> can improve functionality of a prosthetic heart valve and thus improve functionality of a patient's heart.

<FIG> show an exemplary embodiment of an outer skirt <NUM>. <FIG> shows a flattened view of the outer skirt <NUM> prior to its attachment to a prosthetic heart valve. <FIG> show the outer skirt <NUM> attached to the prosthetic heart valve <NUM> in lieu of outer skirt <NUM>.

Referring to <FIG>, the outer skirt <NUM> can comprise a first end portion <NUM> (i.e., the upper end portion as depicted in <FIG>), a second end portion <NUM> (i.e., the lower end portion as depicted in <FIG>), and an intermediate portion <NUM> disposed between the first and second end portions <NUM>, <NUM>. The first end portion <NUM> of the outer skirt <NUM> can include a plurality of alternating projections <NUM> and notches <NUM>, or castellations. The second end portion <NUM> of the outer skirt <NUM> can comprise a substantially straight lower edge <NUM> and can have a plurality of openings <NUM>. The openings <NUM> can be laterally spaced apart relative to each other and laterally aligned with the projections <NUM> of the first end portion <NUM> and laterally offset relative to the notches <NUM> of the first end portion <NUM>. The openings <NUM> can comprise various sizes and/or geometric shapes, including circular, ovular, rectangular, and/or combinations of shapes.

Referring to <FIG>, the projections <NUM> of the first end portion <NUM> can be attached to the inner skirt <NUM> and/or the frame <NUM> of the prosthetic heart valve <NUM> using sutures (as shown) and/or ultrasonic welding. As shown in <FIG>, the lower edge <NUM> of the second end portion <NUM> can be attached to the inner skirt <NUM> and/or the frame <NUM> of the prosthetic heart valve <NUM> using sutures (as shown) and/or ultrasonic welding.

The outer skirt <NUM> can be formed of materials such as PET, PTFE, ePTFE, polyurethane, polyester, and/or other suitable materials configured to restrict and/or prevent blood-flow therethrough.

The outer skirt <NUM> can reduce and/or eliminate perivalvular leakage when the prosthetic heart valve <NUM> is implanted in a native heart valve annulus (e.g., a native aortic valve annulus or a native mitral valve annulus). For example, blood flowing from the inflow end portion <NUM> (<FIG>) toward the outflow end portion <NUM> (<FIG>) of the prosthetic heart valve <NUM> (i.e., antegrade blood flow) can enter the outer skirt <NUM> through the openings <NUM> of the second end portion <NUM>, as best shown <FIG>. Similarly, blood flowing from the outflow end portion <NUM> toward the inflow end portion <NUM> of the prosthetic heart valve <NUM> (i.e., retrograde blood flow) can enter the outer skirt <NUM> through the notches <NUM> of the first end portion <NUM>, as best shown in <FIG>. The blood-flow entering the openings <NUM> and/or the notches <NUM> cannot pass directly through the outer skirt <NUM> because the openings <NUM> and the notches <NUM> are circumferentially offset relative to each other.

<FIG> shows an exemplary embodiment of an outer skirt <NUM>. The outer skirt <NUM> can be configured similar to the outer skirt <NUM> of the prosthetic heart valve <NUM> and can be attached to the prosthetic heart valve <NUM> in a manner similar to the outer skirt <NUM>. In some embodiments and in lieu of or in addition to creases at the inflow end portion <NUM> of the prosthetic heart valve <NUM> (e.g., the creases <NUM> of the outer skirt <NUM>), the outer skirt <NUM> can have creases <NUM> extending axially from a first end portion <NUM> of the outer skirt <NUM> to a second end portion <NUM> of the outer skirt <NUM>. The creases <NUM> can be circumferentially aligned with notches <NUM> and circumferentially offset relative to projections <NUM> of the first end portion <NUM>.

In this manner, the outer skirt <NUM> can expand from a compressed configuration to an expanded configuration (and vice versa) in a uniform and/or predictable manner, similar to a bellows or an accordion. As a result, the creases <NUM> facilitate uniform crimping and/or expansion and/or reduce the crimped radial profile of a prosthetic heart valve in compressed delivery configuration.

In some embodiments, the outer skirt <NUM> can comprise one or more reeds or valves configured to allow blood to flow into and/or through the outer skirt <NUM>.

The outer skirt <NUM> can be formed, for example, by shape setting the outer skirt in this manner. In some embodiments, the creases <NUM> can be formed by ultrasonic welding.

<FIG> show cross-sectional views of the frame <NUM>, the inner skirt <NUM>, and the outer skirt <NUM> in an alternative embodiment of the prosthetic heart valve <NUM> in its expanded configuration (e.g., when deployed in a subject). <FIG> shows a cross-sectional view of the frame <NUM>, the inner skirt <NUM>, and the outer skirt <NUM> through vertical line <NUM> (<FIG> and <FIG>) and <FIG> shows a cross-sectional view of the frame <NUM>, the inner skirt <NUM>, and the outer skirt <NUM> through vertical line <NUM> (<FIG> and <FIG>).

Referring to <FIG>, the inner skirt <NUM> comprises an upper edge portion <NUM> and a lower edge portion <NUM>. The upper edge portion <NUM> of the inner skirt <NUM> can be secured to the inside of the frame <NUM>. The upper edge portion <NUM> of the inner skirt <NUM> can be secured to the inside of frame <NUM> via sutures <NUM> as previously described and as best shown in <FIG>. Alternatively, the upper edge portion <NUM> of the inner skirt <NUM> can be secured to the inside of frame <NUM> via adhesive and/or ultrasonic welding in addition to or in lieu of sutures <NUM>. In the illustrated embodiment of <FIG>, the upper edge portion <NUM> of the inner skirt <NUM> is secured to struts <NUM> (not shown in <FIG>) via sutures <NUM> as best shown in <FIG>. Alternatively, the upper edge portion <NUM> of the inner skirt <NUM> can be secured to any other portion or portions of the frame <NUM>. The upper edge portion <NUM> is shown loosely attached to the frame in <FIG> for purposes of illustration, but typically is tightly secured to the frame struts as depicted in <FIG>.

In the illustrated embodiment of <FIG>, the lower edge portion <NUM> of the inner skirt <NUM> is wrapped around the inflow end portion <NUM> of the frame <NUM> and is exposed to the outside of frame <NUM>. Still referring to <FIG>, the upper edge portion <NUM> of the outer skirt <NUM> can be secured to the outside of the frame <NUM> as previously described. The upper edge portion <NUM> of the outer skirt <NUM> can contain projections <NUM> as best shown in <FIG> that can be secured to struts <NUM> (not shown in <FIG>) with sutures <NUM> as best shown in <FIG>, although such projections are not required and the upper edge can be straight.

The lower edge portion <NUM> of the outer skirt <NUM> can be folded inward towards the frame <NUM> such that folded lower edge portion <NUM> of the outer skirt <NUM> is adjacent to the wrapped lower edge portion <NUM> of the inner skirt <NUM>. The folded lower edge portion <NUM> of the outer skirt <NUM> and the wrapped lower edge portion <NUM> of the inner skirt <NUM> can be secured together and/or secured to the frame <NUM>. In the illustrated embodiment of <FIG>, the folded lower edge portion <NUM> of the outer skirt <NUM> and the wrapped lower edge portion <NUM> of the inner skirt <NUM> are secured only to the apices 22a of the frame <NUM> via sutures <NUM>, with each suture extending through the lower edge portion <NUM>, the lower edge portion <NUM> and around a respective apex 22a. These additional layers of material at the inflow end of the valve increase the material surface area at the inflow end of the valve.

In the illustrated embodiment, the lower edge portion <NUM> of the inner skirt <NUM> is shown extending over the lowermost row I of struts <NUM> along the outer surface of the frame. In other embodiments, the lower edge portion <NUM> can extend farther along the outer surface of the frame and can cover additional rows of struts <NUM>, including rows II, III, or IV. Similarly, the folded lower edge portion <NUM> of the outer skirt <NUM> is shown extending axially over the lowermost row I of struts <NUM>, but can extend farther along the outer surface of the frame and can cover additional rows of struts <NUM>, including rows II, III, or IV.

In other embodiments, the folded lower edge portion <NUM> of the outer skirt <NUM> and the wrapped lower edge portion <NUM> of the inner skirt <NUM> can be secured to any other portion of the frame <NUM>. In other embodiments, the folded lower edge portion <NUM> of the outer skirt <NUM> and the wrapped lower edge portion <NUM> of the inner skirt <NUM> can be secured to each other and/or to the frame <NUM> via adhesive or ultrasonic welding in addition to or in lieu of the sutures <NUM>.

In the illustrated embodiment of <FIG>, the lower edge portion <NUM> of the outer skirt <NUM> and the lower edge portion <NUM> of the inner skirt <NUM> are loosely secured together at the inflow end portion <NUM> of the frame <NUM> and these two layers are secured to the frame only at the apices 22a. This loose connection between the skirt layers, along with the discrete (spaced apart) connections to the frame apices, allows antegrade blood to more easily flow into the space between the frame <NUM> and the outer skirt <NUM>, exposing more of the layers of skirt material to blood, which can enhance the sealing properties, thereby reducing or eliminating perivalvular leakage.

In alternative embodiments, the lower edge portion <NUM> of the outer skirt <NUM> and the lower edge portion <NUM> of the inner skirt <NUM> can be tightly sutured or otherwise secured to each other along the entire circumference of both skirts. Also, one or both layers of the skirts <NUM>, <NUM> can be tightly sutured to the frame <NUM> along the entire circumference of the frame <NUM> (e.g., to the lower rung of struts <NUM>), rather than just to the apices 22a.

<FIG> show another embodiment of an outer skirt <NUM>. <FIG> shows a flattened view of the outer skirt <NUM> prior to its attachment to the prosthetic heart valve <NUM>. <FIG> show the outer skirt <NUM> in a folded configuration as discussed further below.

Referring to <FIG>, the outer skirt <NUM> can comprise a first end portion <NUM> (i.e., the upper end portion as depicted in <FIG>), a second end portion <NUM> (i.e., the lower end portion as depicted in <FIG>), and an intermediate portion <NUM> disposed between the first and second end portions <NUM>, <NUM>. The first end portion <NUM> of the outer skirt <NUM> can include a plurality of alternating projections <NUM> and notches <NUM>, or castellations. The second end portion <NUM> of the outer skirt <NUM> can comprise a plurality of overlapping portions <NUM> and can have a plurality of openings <NUM> paired with the overlapping portions. Each pair of an opening <NUM> and an overlapping portion <NUM> can be laterally spaced apart relative to each other and laterally aligned with the projections <NUM> of the first end portion <NUM> and laterally offset relative to the notches <NUM> of the first end portion <NUM>. When placed around the stent, each overlapping portions <NUM> is radially aligned with a corresponding opening <NUM>. The openings <NUM> can comprise various sizes and/or geometric shapes, including circular, ovular, rectangular, and/or combinations of shapes.

Referring to <FIG>, the overlapping portions <NUM> of the second end portion <NUM> can be folded upwards such that each overlapping portion <NUM> covers one of the openings <NUM>. <FIG> shows a view of the outer skirt <NUM> where the overlapping portions <NUM> are folded behind the openings <NUM>, as viewed from the outside of the skirt <NUM>. <FIG> shows a view of the outer skirt <NUM> similar to <FIG>, but as viewed from the inside of the skirt <NUM>. In some embodiments, the outer skirt <NUM> of <FIG> can be used in place of the outer skirt <NUM> in the exemplary embodiment of <FIG>. In such an embodiment, the overlapping portions <NUM> are folded inwards towards the frame <NUM> and are secured to the folded lower edge portion <NUM> of the inner skirt <NUM> with sutures <NUM>.

The overlapping portions <NUM> can cover and seal the openings <NUM> from the inside of the outer skirt <NUM>. In addition, the overlapping portions <NUM> provide an additional layer of material between the frame <NUM> and the rest of the outer skirt <NUM>. These layers provide additional material surface area and the openings expose more of the material to blood, thus enhancing the sealing effect.

It should be noted that, in some embodiments, the outer skirts <NUM>, <NUM>, <NUM> can comprise creases similar to the creases <NUM>, <NUM> of the outer skirt <NUM>. The creases can be configured to facilitate uniform crimping and/or expansion and/or to reduce the crimped radial profile of a prosthetic heart valve in compressed delivery configuration. In some embodiments, the creases can be formed by ultrasonic welding.

<FIG> and <FIG> show various implantation positions for a prosthetic heart valve <NUM>, including implantation within a dock or anchor placed inside the patient's body prior to valve implantation. <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 embodiments can be adapted to deliver and implant prosthetic devices 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 embodiments can also be used to implant prostheses in other lumens of the body. Further, in addition to prosthetic valves, the delivery assembly embodiments described herein can be adapted to deliver and implant various other prosthetic devices such as stents and/or other prosthetic repair devices.

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. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The methods, apparatus, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present or problems be solved. For example, an outer skirt for a prosthetic heart valve can include one or more features disclosed skirt <NUM>, skirt <NUM>, skirt <NUM>, skirt <NUM>, and/or skirt <NUM>.

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. " Further, the terms "coupled" and "associated" generally mean electrically, electromagnetically, and/or physically (e.g., mechanically or chemically) 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, 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 "integrally formed" and "unitary construction" refer to a construction that does not include any welds, fasteners, or other means for securing separately formed pieces of material to each other.

As used herein, the term "coupled" generally means physically coupled or linked and does not exclude the presence of intermediate elements between the coupled 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;
a leaflet structure (<NUM>) positioned within the frame (<NUM>) and secured thereto;
an annular inner skirt (<NUM>) positioned around an inner surface of the frame (<NUM>), wherein the inner skirt comprises an outflow edge portion (<NUM>) secured to the frame (<NUM>) and an inflow edge portion (<NUM>) secured to the frame (<NUM>); and
an outer skirt (<NUM>; <NUM>; <NUM>; <NUM>) positioned around an outer surface of the frame, wherein the outer skirt (<NUM>; <NUM>; <NUM>; <NUM>) comprises an outflow edge portion (<NUM>) secured to the frame and an inwardly folded inflow edge portion (<NUM>) that is secured to the inflow edge portion (<NUM>) of the inner skirt (<NUM>);
wherein the inflow edge portion (<NUM>) of the inner skirt (<NUM>) wraps around the inflow end (<NUM>) of the frame (<NUM>) and extends at least partially along an outer surface of the frame (<NUM>).