Patent Description:
The heart can suffer from various valvular diseases or malformations that result in significant malfunctioning of the heart, and ultimately require replacement of the native heart valve with an artificial valve. Procedures in which radially collapsible transcatheter heart valves are percutaneously introduced in a compressed state on a catheter and expanded at the treatment location are gaining popularity, especially among patient populations for whom traditional surgical procedures pose a high risk of morbidity or mortality.

It can be important to reduce or prevent blood leakage past the prosthetic valve after implantation. Thus, transcatheter heart valves often include a sealing element such as a paravalvular leakage skirt to reduce the amount of leakage past the prosthetic valve. However, differences between the diameter of the prosthetic valve and the native annulus into which the valve is implanted, along with features of a particular patient's anatomy such as calcification, tissue prominences, recesses, folds, and the like, can make it difficult to achieve a seal between the prosthetic valve and the native annulus. Accordingly, there is a need for improved paravalvular sealing elements for prosthetic heart valves.

The invention is directed to an implantable prosthetic valve as defined in claim <NUM>. Particular embodiments are defined in dependent claims <NUM> - <NUM>. Certain embodiments of the disclosure concern prosthetic valves including various embodiments of sealing elements. In a representative embodiment, an implantable prosthetic valve that is radially collapsible to a collapsed configuration and radially expandable to an expanded configuration comprises an annular frame having an inflow end, an outflow end, and a longitudinal axis. A leaflet structure is positioned within the frame and secured thereto, and a sealing element is secured to the frame. The sealing element comprises a first woven portion extending circumferentially around the frame. The first woven portion comprises a plurality of interwoven filaments. The sealing element further comprises a second woven portion extending circumferentially around the frame and spaced apart from the first woven portion along the longitudinal axis of the frame. At least a portion of the filaments exit the weave of the first woven portion and form loops extending radially outwardly from the frame.

In some embodiments, the filaments that form the loops extend from and return to the first woven portion.

In some embodiments, the first woven portion comprises a first row of loops, and the second woven portion comprises a second row of loops. The loops of the second row of loops can comprise filaments that extend from and return to the second woven portion.

In some embodiment, the loops of the second row of loops are circumferentially offset from the loops of the first row of loops.

In some embodiments, the plurality of interwoven filaments of the first woven portion further comprises at least one first filament interwoven with a plurality of second filaments, and a portion of the at least one first filament forms the loops of the first woven portion.

In some embodiments, the sealing element further comprises an intermediate sealing portion between the first and second woven portions. The intermediate sealing portion comprises a plurality of second filaments, and a portion of the at least one first filament extends along the longitudinal axis of the frame between the first woven portion and the second woven portion, and is interwoven with the second filaments of the intermediate sealing portion.

In some embodiments, a portion of the at least one first filament forms the loops of the second woven portion.

In some embodiments, the second filaments are warp yarns and the at least one first filament is a weft yarn.

In some embodiments, at least one of the warp and weft yarns comprise textured yarns.

In some embodiments, the warp and weft yarns comprise fibers having a diameter of from <NUM> to <NUM> to promote thrombus formation around the sealing element.

In some embodiments, the filaments that form the loops originate from the first woven portion and extend curvilinearly along the longitudinal axis of the frame to the second woven portion.

In some embodiments, the filaments that form the loops exit a weave of the first woven portion and are incorporated into a weave of the second woven portion such that the loops form a floating yarn portion between the first and second woven portions.

In some embodiments, the floating yarn portion comprises a first layer of loops and a second layer of loops radially outward of the first layer of loops.

In some embodiments, the sealing element comprises a first fabric strip, a second fabric strip, and a third fabric strip. A plurality of the filaments that form the loops extend between the first fabric strip and the second fabric strip, and a plurality of the filaments that form the loops extend between the second fabric strip and the third fabric strip. The sealing element is folded about the second fabric strip such that the first fabric strip and the third fabric strip are adjacent each other to form the first woven portion, the filaments extending between the first fabric strip and the second fabric strip form the first layer of loops, and the filaments extending between the second fabric strip and the third fabric strip form the second layer of loops.

In some embodiments, the sealing element is secured to the frame such that the filaments that exit the weave of the first woven portion form the loops when the frame is in the expanded configuration, and are pulled straight when the frame is in the collapsed configuration.

In another representative embodiment, a method comprises mounting any of the prosthetic valves herein to a distal end portion of a delivery apparatus, advancing the delivery apparatus through a patient's vasculature to the heart, and expanding the prosthetic valve in a native heart valve of the heart such that the prosthetic valve regulates blood flow through the native heart valve.

In another representative embodiment, a method of making a sealing element for a prosthetic heart valve comprises weaving at least one weft yarn together with a plurality of warp yarns to form a first woven portion, dropping the at least one weft yarn from a weave of the first woven portion, and looping the at least one weft yarn around a removable warp yarn. The removable warp yarn is spaced apart from the first woven portion, and the at least one weft yarn is looped around the removable warp yarn such that the at least one weft yarn extends over, and is not interwoven with, warp yarns disposed between the first woven portion and the removable warp yarn. The method further comprises reincorporating the at least one weft yarn into the weave of the first woven portion such that the at least one weft yarn forms a loop that extends from and returns to the first woven portion, and removing the removable warp yarn from the sealing element to release the loop formed by the at least one weft yarn.

In some embodiments, before removing the removable warp yarn, the method further comprises repeating the weaving, the dropping, the looping, and the reincorporating to form a plurality of loops about a circumference of the sealing element.

In some embodiments, the method further comprises shape-setting the plurality of loops such that the loops extend outwardly from the sealing element.

In some embodiments, the method further comprises before removing the removable warp yarn, weaving the at least one weft yarn together with warp yarns such that the at least one weft yarn extends beyond the removable warp yarn and forms a second woven portion spaced apart from the first woven portion. The method further comprises dropping the at least one weft yarn from a weave of the second woven portion, and looping the at least one weft yarn around a second removable warp yarn that is spaced apart from the second woven portion. The at least one weft yarn can be looped around the second removable warp yarn such that the at least one weft yarn extends over, and is not interwoven with, warp yarns disposed between the second woven portion and the second removable warp yarn. The method can further comprise reincorporating the at least one weft yarn into the weave of the second woven portion such that the at least one weft yarn forms a second loop that extends from and returns to the second woven portion.

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

The present disclosure concerns embodiments of sealing elements for implantable prosthetic devices, such as prosthetic heart valves. The present inventors surprisingly have discovered that effective sealing can be accomplished by sealing elements including a plurality of filaments, such as yarns and/or fibers, that extend from the sealing element and are configured to prompt a biological response at the cellular level to promote thrombogenesis around the sealing element.

For example, the sealing elements described herein can be configured as fabric skirts including woven portions from which filaments or yarns extend, and which can contact and/or conform to the surrounding anatomy to enhance the sealing properties of the skirt. In certain configurations, the filaments are bound at both ends and form loops that extend radially outwardly from the skirt. As used herein, the term "loop" refers to a closed or partially open curve formed by a yarn or other filament. In some embodiments, the yarns that form the loops extend from and return to the same fabric portion of the skirt. In such configurations, the loops can be arranged in one or more rows extending circumferentially around the skirt. In other configurations, the yarns extend from one fabric portion to another spaced-apart fabric portion such that the loops are arrayed circumferentially around the valve and are oriented along a longitudinal axis of the valve. In still other embodiments, the filaments are bound at one end, and have free ends that extend outwardly from the skirt.

In such configurations, the filaments can be configured to slow retrograde blood flow past the valve. Features such as the diameter, shape, surface texturing, coatings, etc., of the filaments can induce thrombus formation around the filaments to enhance the sealing properties of the skirt.

<FIG> illustrates an exemplary embodiment of a radially collapsible and expandable prosthetic valve <NUM> shown in its deployed, expanded configuration. The prosthetic valve can include an annular stent or frame <NUM>, and a leaflet structure <NUM> situated within and coupled to the frame <NUM>. The frame <NUM> can have an inflow end portion <NUM> and an outflow end portion <NUM>. The leaflet structure can comprise a plurality of leaflets <NUM>, such as three leaflets arranged to collapse in a tricuspid arrangement similar to the aortic valve. Alternatively, the prosthetic valve can include two leaflets <NUM> configured to collapse in a bicuspid arrangement similar to the mitral valve, or more than three leaflets, depending upon the particular application. The prosthetic valve <NUM> can define a longitudinal axis <NUM> extending through the inflow end portion <NUM> and the outflow end portion <NUM>.

The frame <NUM> can be made of any of various biocompatible materials, such as stainless steel or a nickel titanium alloy ("NiTi"), for example Nitinol. With reference to <FIG>, the frame <NUM> can include a plurality of interconnected lattice struts <NUM> arranged in a lattice-type pattern and forming a plurality of apices <NUM> at the outflow end <NUM> of the prosthetic valve. The struts <NUM> can also form similar apices at the inflow end <NUM> of the prosthetic valve (which are covered by a skirt <NUM> described in greater detail below). The lattice struts <NUM> are shown positioned diagonally, or offset at an angle relative to, and radially offset from, the longitudinal axis <NUM> of the prosthetic valve. In other implementations, the lattice struts <NUM> can be offset by a different amount than depicted in <FIG>, or some or all of the lattice struts <NUM> can be positioned parallel to the longitudinal axis of the prosthetic valve.

The lattice struts <NUM> can be pivotably coupled to one another. In the illustrated embodiment, for example, the end portions of the struts <NUM> forming the apices <NUM> at the outflow end <NUM> and at the inflow end <NUM> of the frame can have a respective opening <NUM>. The struts <NUM> also can be formed with apertures <NUM> located between the opposite ends of the struts. Respective hinges can be formed at the apices <NUM> and at the locations where struts <NUM> overlap each other between the ends of the frame via fasteners <NUM>, which can comprise rivets or pins that extend through the apertures <NUM>, <NUM>. The hinges can allow the struts <NUM> to pivot relative to one another as the frame <NUM> is expanded or contracted, such as during assembly, preparation, or implantation of the prosthetic valve <NUM>. For example, the frame <NUM> (and, thus, the prosthetic valve <NUM>) can be manipulated into a radially compressed or contracted configuration, coupled to a delivery apparatus, and inserted into a patient for implantation. Once inside the body, the prosthetic valve <NUM> can be manipulated into an expanded state and then released from the delivery apparatus, as described in greater detail below with reference to <FIG>. Additional details regarding the frame <NUM>, the delivery apparatus, and devices and techniques for radially expanding and collapsing the frame can be found in <CIT>.

As illustrated in <FIG>, the prosthetic valve <NUM> can include a sealing element configured as a skirt <NUM>. The skirt <NUM> can be configured to establish a seal with the native tissue at the treatment site to reduce or prevent paravalvular leakage. The skirt <NUM> can include a main body portion <NUM> disposed about an outer circumference of the frame <NUM>. The skirt <NUM> can be secured to the frame by, for example, a plurality of sutures <NUM> extending in a zig-zag pattern along selected strut members <NUM> between a first edge portion (e.g., an inflow edge portion) <NUM> and a second edge portion (e.g., an outflow edge portion) <NUM> of the skirt <NUM>. For example, in certain embodiments the skirt <NUM> can be sutured to the frame <NUM> along a suture line <NUM> corresponding to a scalloped edge defined by the leaflets <NUM>, which can allow the valve to radially expand and contract without interference from, or pinching of, the skirt. Further details regarding transcatheter prosthetic heart valves, including the manner in which the leaflets <NUM> can be coupled to the frame <NUM> can be found, for example, in <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>.

In the illustrated embodiment, the skirt <NUM> can comprise a plurality of outwardly extending filaments configured as loops <NUM> (also referred to as looped filaments). The loops <NUM> can extend from an outer surface <NUM> of the main portion <NUM>. In certain embodiments, the loops <NUM> can be arranged in rows or tiers <NUM> that extend circumferentially around the frame <NUM>, and are spaced apart from one another along the longitudinal axis <NUM>. For example, in the illustrated embodiment, the loops <NUM> are arranged in three rows <NUM>, with a first row 48A being adjacent the inflow edge portion <NUM> of the skirt, and the rows 48B, 48C being located above the first row 48A along the longitudinal axis <NUM> of the valve. In other embodiments, the skirt <NUM> can include more or fewer rows of loops, depending upon the particular characteristics desired. For example, the skirt <NUM> can include a single row of loops <NUM> (e.g., adjacent the inflow end of the frame), or a plurality of rows of loops along substantially the entire height dimension of the skirt <NUM>.

In particular embodiments, the skirt <NUM> can comprise a cloth material, such as a woven or knitted fabric. <FIG> illustrates a portion of a representative embodiment of the skirt <NUM> made from such a fabric in greater detail. The fabric can comprise a plurality of first yarns <NUM> oriented horizontally in <FIG> and one or more second yarns <NUM> oriented vertically in <FIG> and selectively interwoven with the first yarns <NUM> on a loom. In certain configurations, the first yarns <NUM> can be warp yarns, meaning that during the weaving process the yarns <NUM> are held by the loom, while the second yarns <NUM> are weft yarns, which are interwoven with the warp yarns by a moving shuttle or weft-carrying mechanism during the weaving process. However, in other embodiments the first yarns <NUM> may be weft yarns and the second yarns <NUM> may be warp yarns. In the illustrated configuration, the fabric comprises a single weft yarn <NUM> that is selectively interwoven with the warp yarns <NUM> to form the looped filaments <NUM>, although in other embodiments more than one weft yarn may be used.

<FIG> illustrates an exemplary weaving pattern that can be used to produce the skirt <NUM>. With reference to <FIG>, a first portion 52A of the weft yarn can extend over and under the warp yarns in the fabric from the first edge portion <NUM> to the second edge portion <NUM>. At the second edge portion <NUM>, the weft yarn <NUM> doubles back, and a second portion 52B of the weft yarn extends over and under each of the warp yarns in the fabric in a direction back toward the first edge portion <NUM> in the manner of a plain weave. This can define a side edge of the fabric, and prevent the fabric from unraveling when removed from the loom. At the first edge portion <NUM>, the weft yarn <NUM> can double back again such that a third portion 52C extends over and under the warp yarns <NUM> of a first woven portion configured as a fully woven strip 54A of the fabric. In the illustrated configuration, the fabric can include four such woven strips 54A-54D spaced apart from one another between the first and second edge portions <NUM>, <NUM>, and extending parallel to the warp yarns <NUM>. The woven strips 54A-54D can be spaced apart by respective partially or semi-woven portions 55A-55C (also referred to as intermediate sealing portions). In the fully woven strips 54A-54D, every pass of the weft yarn <NUM> can be incorporated into the weave. In contrast, in the semi-woven portions 55A-55C, only a portion of the passes of the weft yarn are incorporated into the weave. In certain examples, in the woven strips 54A-54D, the warp and weft yarns <NUM>, <NUM> are woven together in a plain weave (or another suitable weave). In other embodiments, the skirt <NUM> need not include the woven portion 54D above the last row of loops <NUM>, depending upon the particular application.

Still referring to <FIG>, at an upper edge <NUM> of the woven strip 54A, the portion 52C of the weft yarn can exit the weave (e.g., the yarn portion 52C is "dropped" from the weave) and can extend or "float" above the warp yarns <NUM> of the semi-woven portion 55A for a distance d<NUM>. In <FIG>, portions of the weft yarn <NUM> that are incorporated into the weave are illustrated in solid lines, and portions of the weft yarn <NUM> that are not incorporated into the weave (such as portion 52C) are illustrated in dashed lines. The portion 52C can then loop around a removable warp yarn 50A (also referred to as a selvedge yarn), and a fourth portion 52D can extend back toward the first edge portion <NUM> above the warp yarns and out of the weave. When the weft yarn portion 52D reaches the woven strip 54A, the portion 52D can be reincorporated into the weave such that the warp yarns of the woven strip 54A extend over and under the weft yarn portion 52D.

At the first edge portion <NUM>, the warp yarn <NUM> can double back again, and a fifth portion 52E can extend in a direction toward the second edge portion <NUM>. The fifth portion 52E can be incorporated into the weave through the semi-woven portion 55A and the woven strip 54B until it reaches an upper edge <NUM> of the woven strip 54B, at which point a sixth portion 52F can exit, or be "dropped" from, the weave. The sixth portion 52F can extend or float above the warp yarns <NUM> of the semi-woven portion 55B for a distance d<NUM> in a direction toward the second edge portion <NUM>. The sixth portion 52F can then loop around a removable warp yarn 50B, and a seventh portion <NUM> of the weft yarn can extend in a direction back toward the first edge portion <NUM> outside of the weave.

When the seventh portion <NUM> reaches the upper edge <NUM> of the woven strip 54B, the seventh portion <NUM> can be reincorporated into the weave such that the warp yarns of the woven strip 54B extend over and under the seventh portion <NUM>. When the seventh portion <NUM> reaches a lower edge portion <NUM> of the woven strip 54B, the weft yarn can double back, and an eighth portion <NUM> can extend in a direction toward the second edge portion <NUM>. The eighth portion <NUM> can be incorporated into the weave through the semi-woven portion 55B and the woven strip 54C until the eighth portion reaches an upper edge portion <NUM> of the woven strip 54C. At this point, a ninth portion 52I can exit the weave and extend a distance d<NUM> over the warp yarns <NUM> of the semi-woven portion 55C toward the second edge portion <NUM>. At the woven strip 54D, the ninth portion 52I can loop around a removable warp yarn 50C, and a tenth weft yarn portion 52J can extend back toward the first edge portion <NUM> outside of the weave.

When the tenth portion 52J reaches the upper edge <NUM> of the woven strip 54C, the weft yarn can be reincorporated into the weave such that an eleventh weft yarn portion <NUM> extends back to the first edge portion <NUM> in the weave. When the portion <NUM> reaches the first edge portion <NUM>, the weft yarn can double back, and the foregoing pattern can be repeated along a length of the fabric (e.g., to the right in <FIG> illustrates two complete instances of the foregoing weave pattern.

When the weave pattern has been repeated a selected number of times (e.g., to produce a fabric having length corresponding to the circumference of the prosthetic valve), the removable warp yarns 50A-50C can be removed from the weave. For example, in the embodiment illustrated in <FIG>, the warp yarns 50A-50C can be pulled out of the fabric in the direction of respective arrows 64A-64C. This can cause the portions of the weft yarn <NUM> that are outside the weave to be released from the fabric, thereby forming the loops <NUM>. For example, when the removable warp yarn 50A is removed from the weave, the portions 52C and 52D of the weft yarn are released from the fabric, and can form a looped filament 44A in extending from the woven strip 54A (e.g., in the manner of terrycloth). Likewise, removing the warp yarn 50B can release the weft yarn portions 52F and <NUM> such that they form a looped filament 44B extending from the woven strip 54B, and removing the warp yarn 50C can release the weft yarn portions 52I and 52J such that they form a looped filament 44C extending from the woven strip 54C.

Thus, removing the warp yarns 50A-50C results in a plurality of looped filaments <NUM> arranged in the three rows 48A-48C extending lengthwise along the skirt <NUM>, as described above. <FIG> illustrates the skirt <NUM> with the removable warp yarn 50A removed for purposes of illustration. Returning to <FIG>, and referring to the Cartesian x- and y-axes for reference, the rows 48A-48C of loops <NUM> can be offset from each other in a direction along the y-axis (e.g., parallel to the longitudinal axis of the valve) by a distance equal to the length of the loops plus the width of the woven strip <NUM> from which the loops extend. For example, the first row 48A of loops <NUM> adjacent the first edge portion <NUM> is offset from the second row 48B of loops by a distance equal to a width W of the woven strip 54A plus the distance d<NUM>, the length of the loops <NUM>.

Meanwhile, although the loops <NUM> are shown axially aligned in <FIG> for purposes of illustration, the loops <NUM> can also be spaced apart from one another in a direction along the x-axis (e.g., circumferentially around the prosthetic valve when the skirt <NUM> is secured to the valve). For example, in the embodiment illustrated in <FIG>, a center or apex of the loop 44B is spaced apart from a center or apex of the loop 44A by a distance x<NUM> corresponding to, for example, the distance along the x-axis occupied by the weft yarn portions 52D and 52E in the weave. Thus, in the illustrated configuration, each loop <NUM> is offset from the next sequential loop <NUM> in the neighboring rows in a direction along the x-axis by the distance x<NUM>. Thus, the loop 44A is offset from the loop 44B by the distance x<NUM> in the negative x direction, and the loop 44C is offset from the loop 44B by the distance x<NUM> in the positive x direction. Loops <NUM> in the same row are offset from each other along the x-axis by a distance equal to <NUM>x<NUM>.

In certain embodiments, when the fabric has been removed from the loom and the removable warp yarns 50A-50C have been removed from the weave, the loops <NUM> can be shape-set such that they extend out of the plane of the fabric (e.g., transverse to the longitudinal axis of the valve and, thus, to the direction of flow through the valve). For example, referring again to <FIG>, the loops <NUM> can be shape-set such that they extend radially outwardly from the surface <NUM> of the skirt <NUM> at an angle when the skirt is secured to the frame.

In certain configurations, one or both of the warp and weft yarns <NUM>, <NUM> can also comprise textured yarns. A representative example is illustrated in <FIG>, which shows an exemplary textured yarn <NUM> and a fully drawn yarn <NUM>. The textured yarn <NUM> includes a plurality of constituent fibers <NUM> that have been crimped, coiled, crinkled, looped, etc., such that the fibers are not as tightly bundled as the fibers <NUM> of the fully drawn yarn <NUM>. This can increase the surface area of the textured yarn <NUM>, which can improve the blood clotting properties of the yarn, as further described below. Additionally, the fibers <NUM> from which the yarns <NUM>, <NUM> are formed can be sized to promote a biological response or interaction at the cellular level between the yarns <NUM>, <NUM> and the blood flowing past the skirt.

For example, blood cells typically range in size from <NUM> to <NUM>. For example, the diameter of red blood cells typically ranges from <NUM> to <NUM>, and the diameter of platelets typically ranges from <NUM> to <NUM>. Thus, utilizing fibers <NUM> having a diameter sized to approximately match the diameter of blood cells (e.g., <NUM> to <NUM>) can promote interaction between the fibers and blood cells at the cellular level. For example, the fibers <NUM> can be configured to promote thrombus formation along the skirt <NUM>, and along the looped filaments <NUM> in particular, thereby improving the sealing characteristics of the skirt.

In certain configurations, the warp and weft yarns can comprise a variety of biocompatible materials, such as natural fibers (e.g., silk, cotton, etc.), synthetic polymeric materials (e.g., polyethylene terephthalate (PET), Nylon, polytetrafluoroethylene (PTFE), etc.), or metals (e.g., Nitinol, gold, etc.). In other embodiments, the skirt <NUM> need not comprise a woven fabric, but can comprise a thin polymeric film or laminate with which the looped filaments are integrally formed, or to which the looped filaments are attached.

The skirt <NUM> can provide a number of significant advantages over known skirt embodiments. For example, the loops <NUM> can obstruct the flow of blood past the valve, reducing the velocity and volume of blood that leaks past the valve after implantation. The flow obstruction provided by the loops <NUM> can increase the dwell time of blood near the skirt. This, together with the fiber diameters described above, can induce thrombus formation and promote sealing between the skirt and the surrounding tissue.

Additionally, the loops <NUM> can be flexible, allowing the loops to conform to the shape of the surrounding anatomy. Because the loops <NUM> extend radially outwardly from the surface of the skirt <NUM>, the free end portions of the loops can also extend into folds and crevices in the surrounding anatomy to promote a more complete seal. Moreover, when the prosthetic valve is implanted in the native aortic valve, blood around the exterior of the valve can apply force to the loops <NUM> during ventricular diastole in a direction that is opposite to the direction of blood flow through the valve. This can enhance the bending of the loops <NUM> away from the skirt <NUM>, further enhancing the sealing properties. Additionally, by extending outwardly from the exterior of the valve, the loops <NUM> can also block thrombi from moving past the valve, reducing the likelihood of stroke.

<FIG> illustrates a prosthetic valve <NUM> including another embodiment of a sealing member or skirt <NUM>. In the illustrated embodiment, the skirt <NUM> can comprise a woven portion configured as a fabric strip <NUM>, and a fringe portion <NUM> comprising a plurality of filaments configured as yarns <NUM> extending from an edge portion <NUM> of the fabric strip <NUM>. In certain examples, the yarns <NUM> can be warp yarns extending from the weave of the fabric strip <NUM> which are not interwoven with any weft yarns, or vice versa. In some embodiments, the yarns <NUM> can be frayed yarns. For example, the yarns <NUM> can comprise a plurality of fibers or threads spun together.

<FIG> schematically illustrates a portion of such a skirt <NUM> in greater detail. In the configuration illustrated in <FIG>, the yarns <NUM> can be frayed such that the constituent fibers <NUM> of the yarns are separated from one another and form fan-like structures <NUM>. For example, in some embodiments, the fibers <NUM> of the yarns <NUM> can have diameters of <NUM> to <NUM>, a size at which electro-static forces between the fibers can dominate gravitational forces, causing the fibers to splay apart. This can increase the surface area of the yarns <NUM>, which can promote a biological response at the cellular level between blood and the fibers <NUM> of the skirt, as described above with respect to the embodiment of <FIG>. Thus, the fibers <NUM> can be configured to promote thrombus formation along the fringe portion <NUM>, thereby improving the sealing characteristics of the skirt <NUM>.

In certain embodiments, the yarns <NUM> can comprise any of a variety of hydrophobic surface treatments or coatings in order to promote separation of the fibers <NUM> and increase the surface area of the fringed portion <NUM>. In other embodiments, the yarns <NUM> can comprise hydrophilic surface treatments, such as polyethylene glycol (PEG), or other coatings that covalently bond to the fibers. The yarns <NUM> can also comprise coatings or treatments to promote a biological response (e.g., thrombus formation) from blood in contact with the yarns, and/or lubricious coatings such as Serene™ lubricious coatings available from Surmodics, Inc. In other embodiments, an electrostatic charge can be applied to the yarns <NUM> such that the fibers <NUM> repel each other to increase the separation of the fibers. In still other embodiments, the fibers <NUM> can be textured fibers, as described above with respect to the embodiment of <FIG>, or coated or felted with short-length, small diameter fibers. In other examples, the yarns <NUM> can also form loops.

With reference to <FIG>, in another configuration, the skirt <NUM> can comprise multiple fabric strips <NUM> arranged one on top of the other in a tiered arrangement. For example, in the illustrated embodiment, the skirt <NUM> can comprise three fabric strips 102A-102C arranged such that the frayed edge portion <NUM> of each strip is oriented toward the outflow end <NUM> of the frame. Although the illustrated embodiment includes three fabric strips 102A-102C, the skirt <NUM> can comprise any suitable number of fabric strips <NUM> depending upon, for example, the width of the fabric strips, the length of the prosthetic valve, etc. In other embodiments, both longitudinal edges of the fabric strips <NUM> can comprise yarns <NUM>.

In another configuration illustrated in <FIG>, the skirt <NUM> can be secured to the struts <NUM> such that it extends along the struts and forms a zig-zag shape. Multiple skirts <NUM> can be secured to the strut members <NUM> of the frame in this fashion, depending upon the particular application.

<FIG> illustrates another embodiment of a prosthetic valve <NUM> configured as the Edwards Lifesciences Corporation SAPIEN® <NUM> prosthetic heart valve described in detail in <CIT>. The prosthetic valve <NUM> includes a radially expandable and collapsible frame <NUM> formed by a plurality of angled strut members <NUM>, and having an inflow end <NUM> and an outflow end <NUM>. Although not shown, the prosthetic valve <NUM> can also include a leaflet structure comprising two leaflets, three leaflets, or any other suitable number of leaflets situated within and secured to the frame as described in <CIT>.

The prosthetic valve <NUM> can comprise an inner skirt <NUM> secured to an interior surface of the frame, and an outer sealing element configured as a skirt <NUM> disposed around the exterior of the frame <NUM>. In the illustrated configuration, the skirt <NUM> can comprise a first circumferentially-extending portion <NUM> situated adjacent the inflow end <NUM> of the frame and a second circumferentially-extending portion <NUM>. The circumferential portions <NUM>, <NUM> can be spaced apart from each other along a longitudinal axis <NUM> of the frame, and coupled together by a plurality of filaments <NUM>. The filaments <NUM> can extend longitudinally along the outside of the frame between the portions <NUM>, <NUM>, and can curve outwardly from the frame when the frame is in the expanded configuration to form loops. The looped filaments <NUM> can be configured to promote sealing by obstructing blood flow past the skirt and increasing the dwell time of blood in the vicinity of the filaments, as described above.

In certain configurations, the circumferential portions <NUM>, <NUM> can be configured as one or more strips of woven fabric. The filaments <NUM> can be yarns that are incorporated into the fabric of the portions <NUM> and <NUM>, and extend axially therebetween. The skirt <NUM> illustrated in <FIG> includes a single layer of looped filaments <NUM> for ease of illustration, although the skirt embodiments described herein can include two or more layers of looped filaments, depending upon the number of fabric strips incorporated into the portions <NUM>, <NUM>. Increasing the number of looped filaments (e.g., by increasing the number of fabric strips) can increase the overall surface area of the sealing element available for thrombogenesis.

For example, <FIG> illustrates a representative embodiment of a skirt <NUM> configured to provide two layers of looped filaments <NUM> when secured to the frame, and laid out flat for purposes of illustration. The skirt <NUM> can comprise a main body <NUM> including a first fabric strip 226A, a second fabric strip 226B, and a third fabric strip 226C. The fabric strip 226B can be located between the fabric strips 226A and 226C. The fabric strip 226B can be spaced apart from the fabric strip 226A by a floating yarn portion 228A comprising a plurality of filaments or yarns <NUM>. Likewise, the fabric strip 226C can be spaced apart from the fabric strip 226B by a floating yarn portion 228B comprising a plurality of yarns <NUM>.

In the illustrated configuration, the first fabric strip 226A can comprise warp and weft yarns woven together. At an edge portion <NUM> of the fabric strip 226A, the yarns <NUM> can exit the weave and extend or "float" to the second fabric strip 226B to form the floating yarn portion 228A. When the floating yarns <NUM> reach the second fabric strip 226B, the yarns can be reincorporated into the woven fabric of the strip 226B. At an edge portion <NUM> of the fabric strip 226B, the yarns <NUM> can exit the weave again, and extend or float from the strip 226B to the strip 226C to form the floating yarn portion 228B. When the floating yarns <NUM> reach the fabric strip 226C, they can be reincorporated into the weave of the fabric strip 226C. In certain configurations, the yarns <NUM> are warp yarns, although the yarns <NUM> may also be weft yarns, or a combination of warp and weft yarns, depending upon the particular application.

Referring to <FIG>, the main body <NUM> of the skirt <NUM> can be folded about the fabric strip 226B such that the fabric strip 226C is adjacent the fabric strip 226A, and such that the floating yarn portions 228A and 228B are overlaid or coextensive with each other. The folded skirt <NUM> can then be secured to the frame (e.g., by suturing) such that the fabric strips 226A, 226C form the first portion <NUM>, and the fabric strip 226B forms the second portion <NUM>. In this manner, the longitudinally-extending yarns <NUM> of the floating yarn portion 228A form a first or radially inward layer of curved yarns or loops, and the longitudinally-extending yarns <NUM> of the floating yarn portion 228B form a second or radially outward layer of curved yarns or loops (or vice versa). To produce the single layer of looped filaments <NUM> illustrated in <FIG>, the skirt <NUM> need only include, for example, the woven strips 226A and 226B, and the floating yarn portion 228A.

Referring to <FIG>, which illustrate a portion of the frame <NUM>, the strut members <NUM> can be arranged end-to-end to form a plurality of rows or rungs of strut members that extend circumferentially around the frame <NUM>. For example, the frame <NUM> can comprise a first or lower row I of angled strut members forming the inflow end <NUM> of the frame; a second row II of strut members above the first row; a third row III of strut members above the second row; a fourth row IV of strut members above the third row, and a fifth row V of strut members above the fourth row and forming the outflow end <NUM> of the frame. The structure and characteristics of the rows I-V of strut members <NUM> are described in greater detail in <CIT>. The strut members <NUM> of the frame <NUM> can also be grouped into columns. For example, the frame <NUM> can include a plurality of first or "type A" columns, and second or "type B" columns arranged alternatingly around the circumference of the frame. In the illustrated configuration, the type A columns comprise the strut members <NUM> on the left side of the diamond-shaped windows <NUM> defined by the rows IV and V of strut members, and the strut members extending downwardly therefrom. The type B columns comprise the strut members <NUM> on the right side of the windows <NUM>, and the strut members extending downwardly therefrom.

With reference to <FIG> and <FIG>, the first portion <NUM> of the skirt <NUM> can be secured (e.g., by suturing) to the first row I of strut members <NUM> adjacent the outflow end of the frame. The second portion <NUM> can be secured along the intersection of the second and third rows II and III of struts <NUM>. A length of the yarns <NUM> can be configured such that the yarns curve radially outwardly from the surface of the frame <NUM> when the frame is in the expanded configuration and form loops. For example, when coupled to the frame, the skirt <NUM> can have a length L corresponding approximately to the sum of the lengths of strut members 204A, 204B, and 204C identified in <FIG>. In this manner, when the frame <NUM> is in the radially compressed or crimped configuration (in which the strut members 204A, 204B, and 204C are axially aligned or nearly aligned with one another), the yarns <NUM> can be pulled straight to reduce the crimp profile of the valve for insertion into a delivery sheath.

In the configuration illustrated in <FIG>, the portions <NUM>, <NUM> of the skirt <NUM> extend generally parallel to each other and are not angled with respect to the longitudinal axis <NUM> of the frame. In other configurations, one or both of the portions <NUM>, <NUM> can be attached to the frame such that they are angled relative to the longitudinal axis <NUM> of the frame. For example, <FIG> illustrates a configuration in which the portion <NUM> is secured to the first row I of strut members such that the portion <NUM> extends parallel to the angled strut members <NUM> around the circumference of the frame <NUM>. In other words, the portion <NUM> forms a zig-zag pattern along the first row I of strut members <NUM> that corresponds to the zig-zag pattern of the strut members of the first row I. The portion <NUM> is secured to the third row III of strut members <NUM>, and also extends parallel to the angled strut members of the third row III.

In embodiments in which the portions <NUM>, <NUM> of the skirt <NUM> extend parallel to the strut members <NUM> of the respective row to which they are secured, the skirt <NUM> can extend between even-numbered rows of strut members, odd-numbered rows of strut members, or from an odd-numbered row to an even-numbered row, or vice versa. For example, in the configuration illustrated in <FIG>, the first portion <NUM> is secured to the first row I, and the second portion <NUM> is secured to the third row III such that the skirt extends between two odd-numbered rows of strut members. With respect to the frame <NUM> illustrated in <FIG>, where the skirt extends from an odd-numbered row to another odd-numbered row (e.g., from row I to row III), or from an even-numbered row to another even-numbered row (e.g., from row II to row IV), the portions <NUM>, <NUM> can be arranged such that the yarns <NUM> extend in a direction parallel to the longitudinal axis <NUM> of the frame. Stated differently, where the skirt <NUM> extends between odd-numbered rows or between even-numbered rows, a given yarn <NUM> can extend from a location along the first portion <NUM> that is secured to a type A column to a location along the second portion <NUM> that is also secured to a type A column.

In configurations in which the skirt extends from an odd-numbered row to an even-numbered row (or vice versa), the portions <NUM>, <NUM> can be circumferentially offset from each other such that the yarns <NUM> extend at an angle to the longitudinal axis <NUM>. For example, with reference to <FIG>, the first portion <NUM> is coupled to the first row I of strut members, and the second portion <NUM> is coupled to the fourth row IV of the strut members. As illustrated in <FIG>, the first and second portions <NUM>, <NUM> of the skirt are offset from each other about the circumference of the frame such that a given yarn <NUM> that extends from a location along the first portion <NUM> that is secured to a type A column of strut members is coupled to a location along the second portion <NUM> that is secured to a type B column of strut members. This allows the yarns <NUM> to extend parallel to the longitudinal axis of the frame when the frame is crimped.

<FIG> illustrates another configuration in which the skirt <NUM> is draped between intersections or apices <NUM> of the strut members <NUM> such that the portions <NUM>, <NUM> hang from the frame <NUM>. For example, in the illustrated configuration the portion <NUM> is secured to intersections of strut members of row I, and the portion <NUM> is secured to intersections of the strut members of rows III and IV. One or both of the portions <NUM>, <NUM> can be secured in this manner, depending upon the particular characteristics desired.

In certain examples, the skirt <NUM> can comprise twisted yarns, or non-twisted yarns. The skirt <NUM> can also comprise core-spun yarns, in which wrapper fibers are spun around a core yarn. The wrapper fibers may be wispy or diffuse in order to increase the surface area of the core-spun yarn to promote a biological response, as described above. In certain embodiments, the skirt <NUM> can also include loops similar to the loops <NUM> of <FIG>, in addition to the floating yarn portions <NUM>.

<FIG> illustrate another skirt <NUM> in which the yarns <NUM> extend between the fabric strips 226A, 226B, and 226C at an angle. For example, referring to <FIG>, the yarns <NUM> of the floating yarn portion 228A extend at an angle to the fabric strips 226A and 226B. The yarns <NUM> of the floating yarn portion 228B can also extend at an angle to the fabric strips 226B and 226C. In this manner, when the main body <NUM> is folded, the yarns <NUM> of the floating yarn portion 228A can be at an angle to or "criss-crossed" with the yarns of the floating yarn portion 228B to form a mesh or web as shown in <FIG>. In some embodiments, the yarns can extend at an angle of from <NUM> degrees to <NUM> degrees. In certain configurations, having the yarns of the floating yarn portions 228A and 228B cross each other at an angle can reduce the potential for gaps between the yarns resulting from the yarns clustering together. In some embodiments, the yarns of the floating yarn portion 228A and the floating yarn portion 228B can be parallel to each other.

<FIG> illustrates the prosthetic valve <NUM> and frame <NUM> of <FIG> including another embodiment of a skirt <NUM>. The skirt <NUM> can comprise first and second circumferentially-extending portions <NUM>, <NUM> spaced apart from each other and coupled together by a plurality of filaments configured as yarns <NUM> extending longitudinally along the frame, similar to the skirt <NUM>. In the embodiment illustrated in <FIG>, the portions <NUM>, <NUM> can be relatively wider than the portions <NUM>, <NUM> of the skirt <NUM>, such that edge portions of the portions <NUM>, <NUM> curve outwardly from the frame <NUM> in the expanded configuration, along with the filaments <NUM>. The second portion <NUM> can also include a plurality of connection portions <NUM> extending upwardly (e.g., toward the outflow end <NUM> of the frame) from the portion <NUM> and secured to the struts <NUM> (e.g., by suturing).

In the illustrated configuration, the skirt <NUM> includes a single layer of longitudinally-extending yarns <NUM>. <FIG> illustrates a representative configuration of the skirt <NUM> laid flat before the skirt is attached to the frame. The first and second portions <NUM>, <NUM> can comprise woven fabric strips, similar to the skirt <NUM>. The fabric portions <NUM>, <NUM> can be spaced apart by a floating yarn portion <NUM> through which the yarns <NUM> extend. In some embodiments, the yarns <NUM> can be warp yarns, and the floating yarn portion <NUM> can be formed by omitting the weft yarns from the floating yarn portion, or by removing selected weft yarns from the weave.

When the skirt <NUM> is secured to the frame, the first portion <NUM> can be folded around the inflow end portion <NUM> of the frame <NUM> such that the first portion is partially disposed within the frame. After implantation, blood can flow through the floating yarn portion <NUM> and drain from the skirt. In certain configurations, the skirt <NUM> can have a reduced crimp profile because the skirt is not folded before it is secured to the frame. In other configurations, the portions <NUM>, <NUM> can be sized such that the floating yarn portion <NUM> is located on a lower or distal aspect of the skirt when the frame is expanded. For example, <FIG> is a perspective view of the distal or inflow end portion of the frame <NUM> illustrating the yarns <NUM> located distally of the inflow end portion <NUM>.

<FIG> illustrates another configuration of the skirt <NUM> in which the yarns <NUM> are configured to curve over or around the portions <NUM>, <NUM> before being reincorporated into the weave. For example, referring to <FIG> and <FIG>, the skirt <NUM> can be secured to the frame such that the yarns <NUM> extend from the distal edge portion of the fabric strip 226A, double back and extend proximally and over the fabric strip 226B to the proximal edge portion of the strip 226B such that the yarns form a C-shaped arc. In other embodiments, one or both of the fabric strips 226A, 226B can be omitted, and the yarns <NUM> can be secured to the frame by being looped through the strut members <NUM>.

The disclosed prosthetic valve embodiments can be radially collapsed and delivered to the heart percutaneously using any of a variety of catheter-based delivery systems. For example, <FIG> shows a representative example of a delivery assembly <NUM> configured for use with the prosthetic valve <NUM> of <FIG> and described in detail in <CIT>. The delivery assembly <NUM> can include a handle <NUM>, an elongate shaft <NUM> extending distally from the handle <NUM>, and a plurality of actuation members <NUM> (e.g., in the form of positioning tubes) extending through the shaft and distally outwardly from a distal end <NUM> of the shaft <NUM>. The actuation members <NUM> can be coupled to select apices of the valve frame <NUM>.

Initially, the prosthetic valve <NUM> can be in a radially collapsed configuration within a sheath <NUM> of the shaft <NUM>. When the distal end of the delivery apparatus has been advanced through the patient's vasculature to the treatment site, the prosthetic valve <NUM> can be advanced from the sheath <NUM> using a rotatable actuator <NUM> on the handle <NUM>. The prosthetic valve <NUM> can then be positioned at the treatment site, expanded, and deployed using a release assembly generally indicated at <NUM>. Other delivery systems that can be used in combination with the prosthetic valve embodiments described herein can be found in <CIT> and <CIT>.

<FIG> illustrate additional embodiments of fabric sealing elements that include a plurality of yarns or fibers that extend from the sealing elements to form loops in the manner of a looped pile to increase the surface area available for thrombogenesis and tissue growth. For example, <FIG> schematically illustrates a portion of a sealing element <NUM> including a plurality of first yarns <NUM> interwoven with a plurality of second yarns <NUM>. In certain embodiments, the first yarns <NUM> can be warp yarns, and the second yarns <NUM> can be weft yarns, or vice versa. The warp yarns <NUM> can be configured to form loops <NUM> that extend outwardly from the plane of the page, and extend over one or more weft yarns <NUM>. For example, in the embodiment of <FIG>, the sealing element can comprise warp yarns 502A and warp yarns 502B. The warp yarns 502A can form the loops <NUM>, while one or more warp yarns 502B can be interposed between warp yarns 502A. For example, in the illustrated embodiment, there are two warp yarns 502B between the two warp yarns 502A, although there may be any number of warp yarns 502B depending upon, for example, the desired spacing between the loops <NUM>.

The warp yarns 502A can also change direction where they form the loops <NUM>. For example, in the embodiment of <FIG>, the loops <NUM> can extend across one or more weft yarns <NUM> at an angle to the weft yarns <NUM>. Stated differently, the points where the loops <NUM> originate and return can be offset from each other along the x-axis (note Cartesian coordinate axes shown). The loops <NUM> can alternately extend in the positive x-direction and in the negative x-direction such that straight portions of the yarns 502A between loops <NUM> are offset from each other along the x-axis. This can provide certain advantages, such as preventing movement of or "locking" the warp yarns 502A relative to the weft yarns <NUM>. Additionally, when the sealing member <NUM> is attached to a prosthetic valve with the warp yarns <NUM> extending axially in the direction of a longitudinal axis of the valve, the width W of the loops <NUM> can be oriented perpendicular, or substantially perpendicular, to the direction of blood flow through the valve such that the loops <NUM> present a relatively large flow obstruction. This can promote blood stasis and sealing around the prosthetic valve. The loop density (e.g., the number of loops per inch) of the pile can be varied by, for example, varying the length of the straight portions of the yarns 502A between the loops <NUM>. Shortening the distance between loops <NUM> can increase the loop density of the pile, as shown in <FIG> and <FIG>, while increasing the distance between the loops <NUM> can decrease the loop density of the pile. The width of the loops <NUM> can be determined by, for example, the number of warp yarns over which the loops extend. For example, in <FIG> the loops extend over two warp yarns 502B such that the loops <NUM> of <FIG> are wider relative to the loops <NUM> of <FIG>.

In certain embodiments, the loops <NUM> can be formed using warp-knitting techniques. In certain examples, the first warp yarns 502A can comprise <NUM> denier, <NUM> filament (20d/18f) and/or 30d/18f texturized yarns. The second warp yarns 502B can comprise 20d/18f yarns twisted with <NUM> twists per inch (tpi). In certain examples, the weft yarns <NUM> can be 20d/18f yarns with <NUM> tpi. The warp and weft yarns can be made from any of various biocompatible polymers, such as PET, UHMWPE, PTFE, etc. In other embodiments, the warp and/or weft yarns can have any selected denier and/or filament count, and can be made from any suitable natural or synthetic material.

In some embodiments, loops may be formed on a prosthetic valve skirt by embroidery. In a representative embroidery technique, a yarn or thread is stitched to or through a base or foundation layer (e.g., a fabric), allowing a variety of shapes or patterns to be produced on the surface of the foundation layer. <FIG> illustrates a portion of a skirt <NUM> including a plurality of loops <NUM> embroidered into a base skirt fabric <NUM>, according to one embodiment. The base skirt fabric can comprise a plurality of first yarns <NUM> interwoven with a plurality of second yarns <NUM> in, for example, a plain weave. Referring to <FIG>, the loops <NUM> can be formed using a third yarn configured as an embroidery yarn <NUM>, which may be a relatively high-density yarn or suture. In certain embodiments, in addition to the first or foundation layer <NUM>, the skirt <NUM> may also optionally include a second layer configured as a locking layer <NUM>. In particular embodiments, the locking layer <NUM> can comprise a relatively low-density, light, and/or thin yarn or suture that can be used to lock the embroidery yarn <NUM> on the back of the foundation layer <NUM>.

As noted above, loops may be embroidered on the surface of the prosthetic valve skirt having any specified location, length, width, spacing, shape, and/or pattern. <FIG> illustrate just a few examples of the patterns that may be produced using the embroidery technique described above. For example, <FIG> illustrates a prosthetic valve skirt <NUM> including a plurality of loops generally indicated at <NUM> embroidered onto the skirt and forming a plush portion or pile <NUM>. The plush portion <NUM> can include a plurality of angled portions <NUM> extending circumferentially around the skirt <NUM> in a zig-zag pattern from an end portion <NUM> (e.g., an inflow end portion) of the skirt to midway up the height of the skirt. <FIG> illustrates another variation of the plush portion <NUM> in which the plush portion defines cells <NUM>. In certain embodiments, the cells <NUM> can correspond to openings or cells defined by the struts of the frame, such as the struts <NUM> of the prosthetic valve <NUM> of <FIG>. In other embodiments, the cells of the plush portion <NUM> can correspond to the size and shape of the frame openings defined by the struts of the frame <NUM> of <FIG>. <FIG> illustrates another variation of the plush portion <NUM> including straight portions <NUM> extending between adjacent angled portions <NUM>. In certain embodiments, the loops <NUM> of <FIG> can be formed on the underlying fabric of the skirt <NUM> by embroidery.

<FIG> illustrates a prosthetic heart valve <NUM> including another embodiment of a sealing member or skirt <NUM> on a frame <NUM> configured as the frame of the Edwards Lifesciences Corporation SAPIEN® <NUM> prosthetic heart valve. The skirt <NUM> can comprise a plurality of woven portions configured as fabric strips <NUM> extending circumferentially around the frame. Each of the fabric strips <NUM> can comprise a corresponding fringe portion <NUM> comprising a plurality of filaments <NUM> extending radially outwardly at an angle from a circumferential edge portion (e.g., an inflow or outflow edge portion) of the fabric strip <NUM>, similar to the skirt <NUM> of <FIG> above. In the illustrated embodiment, the skirt <NUM> can comprise three fabric strips 806A-806C having corresponding fringe portions 808A-808C. The fringe portion 808A of the fabric strip 806A can extend from an inflow edge <NUM> of the fabric strip 806A located proximate an inflow end <NUM> of the prosthetic valve. The filaments <NUM> of the fringe portion 808A can extend to about the second row II of strut members (see <FIG>). The filaments <NUM> of the second fabric strip 806B can extend from an inflow edge <NUM> of the fabric strip 806B, and can extend to about the level of the third row III of struts. The filaments <NUM> of the third fabric strip 806C can extend from an outflow edge <NUM> of the fabric strip 806C to about the level of the fourth row IV of struts.

The filaments <NUM> may comprise or originate from frayed yarns, textured yarns, etc. In certain embodiments, the fabric strips <NUM> of the sealing member <NUM> can comprise a yarn density of from <NUM> to <NUM> yarns per inch, <NUM> to <NUM> yarns per inch, <NUM> to <NUM> yarns per inch, or <NUM> to <NUM> yarns per inch. In certain embodiments, the fabric strips of the sealing member <NUM> can have a yarn density of <NUM> yarns per inch, or <NUM> yarns per inch. The yarns may have any suitable filament density, such as <NUM> to <NUM> filaments per yarn, <NUM> to <NUM> filaments per yarn, or <NUM> to <NUM> filaments per yarn. In particular embodiments, the yarns can comprise textured yarns having <NUM> filaments per yarn. The filaments may have thicknesses from <NUM> to <NUM>, <NUM> to <NUM>, or <NUM> to <NUM>. In particular embodiments, the filaments can have a thickness or diameter of <NUM>.

<FIG> show a main cushioning layer, covering, or sealing member <NUM>, according to another embodiment according to the invention. The sealing member <NUM> comprises a fabric body having a plurality of woven portions and a plurality of elastic, stretchable portions configured as floating yarn portions, and can be incorporated into any of the prosthetic valve outer coverings described herein. <FIG> illustrates the sealing member <NUM> in a laid-flat configuration where the x-axis corresponds to the circumferential direction and the y-axis corresponds to the axial direction when the sealing member is attached to a frame of a prosthetic valve. The sealing member <NUM> comprises a plurality of first woven portions <NUM> configured as woven strips or stripes extending along the x-axis, a plurality of second woven portions <NUM> configured as woven strips or stripes extending along the x-axis, and a plurality of floating yarn portions, strips, or stripes <NUM> extending along the x-axis. The various woven and floating yarn portions are spaced apart from each other along the y-axis. In the illustrated configuration, the first woven portions <NUM> comprises a weave pattern that is different from the weave pattern of the second woven portions <NUM>, as described in greater detail below.

For example, in the illustrated configuration, the sealing member <NUM> can comprise a first woven portion 1002A. Moving in a direction along the positive y-axis, the sealing member <NUM> can further comprise a second woven portion 1004A, a floating yarn portion 1006A, a second woven portion 1004B, a floating yarn portion 1006B, a second woven portion 1004C, a floating yarn portion 1006C, a second woven portion 1004D, a floating yarn portion 1006D, a second woven portion 1004E, a first woven portion 1002B, a second woven portion 1004F, a floating yarn portion 1006E, a second woven portion <NUM>, and a first woven portion 1002C at the opposite end of the sealing member from the first woven portion 1002A. In other words, the first woven portion 1002B and each of the floating yarn portions 1006A-1006E can be located between two second woven portions <NUM> such that the first woven portion 1002B and each of the floating yarn portions 1006A-1006E are bounded or edged in a direction along the x-axis by respective second woven portions <NUM>.

Referring to <FIG> and <FIG>, the sealing member <NUM> can comprise a plurality of first yarns <NUM> oriented generally along the x-axis and a plurality of second yarns <NUM> oriented generally along the y-axis. In certain configurations, the first yarns <NUM> can be warp yarns, meaning that during the weaving process the yarns <NUM> are held by the loom, while the second yarns <NUM> are weft yarns, which are interwoven with the warp yarns by a moving shuttle or weft-carrying mechanism during the weaving process. However, in other embodiments the first yarns <NUM> may be weft yarns and the second yarns <NUM> may be warp yarns.

Each of the first yarns <NUM> and the second yarns <NUM> can comprise a plurality of constituent filaments <NUM> that are spun, wound, twisted, intermingled, interlaced, etc., together to form the respective yarns. Exemplary individual filaments <NUM> of the second yarns <NUM> can be seen in <FIG>. In some embodiments, the first yarns <NUM> can have a denier of from about <NUM> D to about <NUM> D, about <NUM> D to about <NUM> D, about <NUM> D to about <NUM> D, about <NUM> D to about <NUM> D, or about <NUM> D to about <NUM> D. In some embodiments, the first yarns <NUM> can have a filament count of <NUM> to about <NUM> filaments per yarn, about <NUM> to about <NUM> filaments per yarn, about <NUM> to about <NUM> filaments per yarn, about <NUM> to about <NUM> filaments per yarn, about <NUM> to about <NUM> filaments per yarn, or about <NUM> to about <NUM> filaments per yarn. In particular embodiments, the first yarns <NUM> can have a denier of about <NUM> D and a filament count of <NUM> filaments per yarn. The first yarns <NUM> may also be twisted yarns or non-twisted yarns. In the illustrated embodiment, the filaments <NUM> of the first yarns <NUM> are not texturized. However, in other embodiments, the first yarns <NUM> may comprise texturized filaments.

The second yarns <NUM> can be texturized yarns comprising a plurality of texturized filaments <NUM>. For example, the filaments <NUM> of the second yarns <NUM> can be texturized, for example, by twisting the filaments, heat-setting them, and untwisting the filaments as described above. In some embodiments, the second yarns <NUM> can have a denier of from about <NUM> D to about <NUM> D, about <NUM> D to about <NUM> D, about <NUM> D to about <NUM> D, or about <NUM> D to about <NUM> D. In some embodiments, a filament count of the second yarns <NUM> can be from <NUM> filament per yarn to about <NUM> filaments per yarn, about <NUM> to about <NUM> filaments per yarn, about <NUM> to about <NUM> filaments per yarn, or about <NUM> to about <NUM> filaments per yarn. In particular embodiments, the second yarns <NUM> can have a denier of about <NUM> D and a filament count of about <NUM> filaments per yarn.

The first yarns <NUM> and the second yarns <NUM> can be woven together to form the woven portions of the sealing member, as noted above. For example, in the first woven portions 1002A-1002C, the first and second yarns <NUM>, <NUM> can be woven together in a plain weave pattern in which the second yarns <NUM> (e.g., the weft yarns) pass over a first yarn <NUM> (e.g., a warp yarn) and then under the next first yarn in a repeating pattern. This weave pattern is illustrated in detail in <FIG>. In some embodiments, the density of the first yarns <NUM> can be from about <NUM> yarns per inch to about <NUM> yarns per inch, about <NUM> yarns per inch to about <NUM> yarns per inch, or about <NUM> yarns per inch to about <NUM> yarns per inch. In certain embodiments, the first woven portion 1002A and the first woven portion 1002C can be configured as selvedge portions, and can have a lower yarn density than the first woven portion 1002B to facilitate assembly on a valve frame. Other weave patterns may also be used, such as over two under two, over two under one, etc. The first woven portions may also be woven in plain weave derivative patterns such as twill, satin, or combinations of any of these.

In the second woven portions 1004A-<NUM>, the first and second yarns <NUM>, <NUM> can be interwoven in another pattern that is different from the weave pattern of the first woven portions 1002A-1002C. For example, in the illustrated embodiment, the first and second yarns <NUM>, <NUM> can be woven together in a leno weave pattern in the second woven portions 1004A-<NUM>. <FIG> illustrates the leno weave of the second woven portion 1004B in greater detail. With reference to <FIG>, the leno weave can comprise one or more leno yarns or "leno ends" <NUM>, and four first yarns 1008A, 1008B, 1008C, and 1008D, also referred to as "warp ends. " The pattern illustrated in <FIG> includes a single leno yarn <NUM> in the manner of a half-leno weave. However, in other embodiments, the leno weave pattern may be a full-leno weave comprising two intertwining leno yarns <NUM>, or other leno-derived weaves. Examples of various leno weaves and associated weaving techniques are illustrated in <FIG>.

In the half-leno weave illustrated in <FIG>, the first yarns 1008A-1008D can extend parallel to the x-axis, and the second yarns <NUM> can be interwoven with the first yarns 1008A-1008D in, for example, a plain weave. The leno yarn <NUM> can weave around the first yarns 1008A-1008D such that the leno yarn <NUM> crosses over, or on top of, the first yarns 1008A-1008D with each pass in the positive y-direction, crosses beneath or behind the next second yarn <NUM> in the x-direction, and extends back over the first yarns 1008A-1008D in the negative y-direction. This pattern can be repeated along the length of the second woven portion 1004B. In this manner, the second woven portions <NUM> can be relatively narrow, strong woven portions spaced axially from each other along the frame when the sealing element is mounted to a frame. The leno yarn <NUM> can serve to keep the first yarns 1008A-1008D and the second yarns <NUM> in place with respect to each other as the prosthetic valve is crimped and expanded, and can impart strength to the second woven portions <NUM> while minimizing width.

In certain embodiments, each of the second woven portions 1004A-<NUM> can comprise the leno weave pattern described above. In other embodiments, one or more of the second woven portions 1004A-<NUM> may be configured differently, such as by incorporating more or fewer first yarns <NUM> in the leno weave, having multiple leno ends woven around multiple groupings of yarns <NUM>, etc. In yet other embodiments, a chemical locking method can be used where the leno weave and/or a plain weave includes warp yarns having core-sheath construction filaments. The sheath of the individual filaments can be made of low-melt temperature polymers such as biocompatible polypropylene, and the core of the filaments be made of another biocompatible polymer such as polyester. After the weaving process, the heat setting process described below can enable the softening and/or melting of the sheath. Upon cooling, the softened sheath polymer can bond the core polyester filaments together. This can create a bonded body enabling locking of the woven structure.

Referring again to <FIG>, the floating yarn portions <NUM> can comprise yarns extending in only one axis between respective second woven portions <NUM> that are spaced apart from each other along the y-axis. For example, taking the floating yarn portion 1006A as a representative example, the floating yarn portion 1006A can comprise a plurality of second yarns <NUM> that exit the leno weave of the second woven portion 1004A, extend across the floating yarn portion 1006A, and are incorporated into the leno weave of the second woven portion 1004B. In some embodiments, the density of the second yarns in the floating yarn portions <NUM> can be from about <NUM> to about <NUM> yarns per inch, about <NUM> to about <NUM> yarns per inch, or about <NUM> to about <NUM> yarns per inch. In particular embodiments, the density of the second yarns <NUM> can be about <NUM>-<NUM> yarns per inch. In other embodiments, the floating yarn portions can include first yarns <NUM> disposed under or over, but not interwoven with, the second yarns <NUM> such that the second yarns float over the first yarns or vice versa. In yet other embodiments, the floating yarn portions may instead be configured as any other elastically stretchable structure, such as elastically stretchable woven, knitted, braided, or non-woven fabrics, or polymeric membranes, to name a few, that is elastically stretchable at least in the axial direction of the prosthetic valve.

In the illustrated embodiment, each of the woven portions 1002A-1002C and 1004A-<NUM>, and each of the floating yarn portions 1006A-1006E can have width dimensions in the y-axis direction. The widths of the constituent portions can be configured such that the overall length L<NUM> (<FIG>) of the sealing member <NUM> generally corresponds to the axial length of a prosthetic heart valve in the expanded configuration. For example, in the illustrated embodiment the first woven portions 1002A and 1002C can each have a width W<NUM>. In certain embodiments, the width W<NUM> can be configured such that portions of the first woven portions 1002A and 1002C can be folded over the inflow and outflow ends of the frame of a prosthetic valve.

The first woven portion 1002B can have a width W<NUM>. With reference to <FIG>, when the sealing member <NUM> is used in combination with the frame of the Edwards Lifesciences SAPIEN® <NUM> prosthetic heart valve, the width W<NUM> can be configured to correspond to the axial dimension of the frame openings defined by the strut members between the fourth row IV and the fifth row V of struts. In some embodiments, the width W<NUM> of the first woven portion 1002B can be about <NUM> to about <NUM>, about <NUM> to about <NUM>, or about <NUM> to about <NUM>. In particular embodiments, the width W<NUM> can be about <NUM>.

The second woven portions 1004A-<NUM> can have widths W<NUM> (<FIG>). In the illustrated embodiment, all of the second woven portions 1004A-<NUM> have the width W<NUM>, but one or more of the second woven portions may also have different widths. In certain embodiments, the width W<NUM> can be relatively short, such as about <NUM> to about <NUM>, about <NUM> to about <NUM>, or about <NUM> to about <NUM>. In particular embodiments, the width W<NUM> can be about <NUM>.

With reference to <FIG> and <FIG>, in certain embodiments the sealing member <NUM>, and in particular the floating yarn portions 1006A-1006E, can be resiliently stretchable between a first, natural, or relaxed configuration (<FIG> and <FIG>) corresponding to the radially expanded state of the prosthetic valve, and a second, elongated, or tensioned configuration (<FIG> and <FIG>) corresponding to the radially compressed state of the prosthetic valve. Thus, the floating yarn portions 1006A-1006E can have initial widths W<NUM> when the sealing member <NUM> is in the relaxed, unstretched state. <FIG> illustrates a portion of the floating yarn portion 1006B in the natural, relaxed state. When the fabric is in the relaxed state, the textured filaments <NUM> of the second yarns <NUM> can be kinked and twisted in many directions such that the floating yarn portion 1006B has a bulky, billowy, or pillow-like quality. When tensioned, the kinks, twists, etc., of the filaments <NUM> can be pulled at least partially straight along the y-axis, causing the second yarns <NUM> to elongate. With reference to <FIG>, the width of the floating yarn portions <NUM> can thus increase to a second width W<NUM> that is larger than the initial width W<NUM>.

The cumulative effect of the floating yarn portions 1006A-1006E increasing in width from the initial width W<NUM> to the second width W<NUM> is that the overall axial dimension of the sealing member <NUM> can increase from the initial length L<NUM> (<FIG>) to a second overall length L<NUM> (<FIG>) that is greater than the first length L<NUM>. <FIG> illustrates the sealing member <NUM> in the stretched configuration with the second yarns <NUM> of the floating yarn portions 1006A-1006E straightened under tension such that the overall length of the sealing member increases to the second length L<NUM>. In certain embodiments, the size, number, spacing, etc., of the floating yarn portions <NUM>, and the degree of texturing of the constituent second yarns <NUM>, can be selected such that the second length L<NUM> of the sealing member <NUM> corresponds to the length of a frame of a prosthetic valve when the prosthetic valve is crimped for delivery on a delivery apparatus. In particular embodiments, the relaxed initial width W<NUM> of the floating yarn portions <NUM> can be about <NUM> to about <NUM>, about <NUM> to about <NUM>, or about <NUM> to about <NUM>. In particular embodiments, the initial width W<NUM> can be about <NUM>.

<FIG> illustrates an edge portion of the sealing member <NUM> gripped between a pair of grippers <NUM>. In certain embodiments the bulky, billowy nature of the texturized yarns <NUM> in the floating yarn portions <NUM> can result in the floating yarn portions <NUM> having a thickness t<NUM> that is greater than a thickness t<NUM> of the woven portions <NUM> and <NUM>. For example, in certain embodiments the thickness t<NUM> of the floating yarn portions <NUM> can be two times, three times, four times, five times, six times, or even ten times greater than the thickness t<NUM> of the woven portions <NUM> and <NUM>, or more, when the sealing member is in the relaxed state. This can allow the floating yarn portions <NUM> to cushion the native leaflets between the valve body and/or against an anchor or ring into which the prosthetic valve is implanted. The floating yarn portions <NUM> can also occupy voids or space in the anatomy, and/or promote tissue growth into the floating yarn portions, as in the embodiments described above. When tension is applied to stretch the floating yarn portions <NUM>, the thickness t<NUM> can decrease as the texturized second yarns <NUM> straighten. In certain embodiments, the thickness t<NUM> can be equal or nearly equal to the thickness t<NUM> of the woven portions <NUM> and <NUM> when the sealing member is in the tensioned state. When the tension on the sealing member <NUM> is released, such as during expansion of the prosthetic valve, the yarns <NUM> can resume their texturized shape and the thickness of the floating yarn portions <NUM> can return to the initial thickness t<NUM>.

In certain embodiments, the floating yarn portions 1006A-1006E can be configured such that the sealing member <NUM> can elongate by about <NUM>% to about <NUM>%, about <NUM>% to about <NUM>%, about <NUM>% to about <NUM>%, about <NUM>% to about <NUM>%, about <NUM>% to about <NUM>%, or about <NUM>% to about <NUM>%. In particular embodiments, the floating yarn portions 1006A-1006E can be configured to allow the sealing member <NUM> to elongate by about <NUM>%, corresponding to the elongation of the frame <NUM> between the expanded and crimped configurations. As noted above, the increase in width of the floating yarn portions 1006A-1006E can also result in a corresponding decrease in thickness of the floating yarn portions, reducing the crimp profile of the prosthetic valve during delivery.

In some embodiments, the first and second yarns <NUM> and <NUM> can comprise any of various biocompatible thermoplastic polymers such as PET, Nylon, ePTFE, UHMWPE, etc., or other suitable natural or synthetic fibers. In certain embodiments, the sealing member <NUM> can be woven on a loom, and can then be heat-treated or heat-set to achieve the desired size and configuration. For example, depending upon the material selected, heat-setting can cause the sealing member <NUM> to shrink. Heat-setting can also cause a texturizing effect, or increase the amount of texturizing, of the second yarns <NUM>. After heat treatment, the openings <NUM> can be created in the first woven portion 1002B (e.g., by laser cutting), and the sealing member can be incorporated into an outer covering such as the covering <NUM> for assembly onto a prosthetic valve. In some embodiments, the openings <NUM> can also be created before heat treatment.

The loops, filaments, floating portions, etc., of the prosthetic sealing members described herein can be configured to promote a biological response in order to form a seal between the prosthetic valve and the surrounding anatomy, as described above. In certain configurations, the sealing elements described herein can be configured to form a seal over a selected period of time. For example, in certain embodiments, the open, porous nature of the loops, filaments, yarns, etc., can allow a selected amount of paravalvular leakage around the prosthetic valve in the time period following implantation. The amount paravalvular leakage past the seal structure may be gradually reduced over a selected period of time as the biological response to the loops, filaments, yarns, etc., causes blood clotting, thrombus formation, etc. In some embodiments, the sealing members, and in particular the loops, filaments, yarns, etc., of the paravalvular sealing structure, may be treated with one or more agents that inhibit the biological response to the sealing structures. For example, in certain embodiments, the loops, filaments, yarns, etc., may be treated with heparin. In certain embodiments, the amount or concentration of the agent(s) may be selected such that the agents are depleted after a selected period of time (e.g., days, weeks, or months) after valve implantation. As the agent(s) are depleted, the biological response to the loops, filaments, yarns, etc., of the sealing structures may increase such that a paravalvular seal forms gradually over a selected period of time. This may be advantageous in patients suffering from left atrial remodeling (e.g., due to mitral regurgitation), by providing an opportunity for the remodeling to reverse as regurgitation past the prosthetic valve is gradually reduced.

<FIG> illustrate various leno weaves and leno weaving techniques that may be used to produce the sealing member <NUM>, or any of the other sealing members described herein. <FIG> is a cross-sectional view illustrating a shed (e.g., the temporary separation of warp yarns to form upper and lower warp yarns) in which a leno yarn, "leno end," or "crossing end" <NUM> forms the top shed on the left of the figure above a weft yarn <NUM> and a standard warp yarn <NUM> forms the bottom shed. <FIG> illustrates a successive shed in which the leno yarn <NUM> forms the top shed on the right of the standard warp yarn <NUM>. In <FIG>, the leno yarn <NUM> may cross under the standard yarn <NUM> in a pattern known as bottom douping. Alternatively, the leno yarn <NUM> may cross over the standard yarn <NUM>, known as top douping, as in <FIG>.

<FIG> illustrates a leno weave interlacing pattern produced when one warp beam is used on a loom, and the distortion or tension of the leno yarns <NUM> and the standard yarns <NUM> is equal such that both the yarns <NUM> and the yarns <NUM> curve around the weft yarns <NUM>. <FIG> illustrates a leno weave lacing pattern produced when multiple warp beams are used, and the leno yarns <NUM> are less tensioned than the standard yarns <NUM> such that the standard yarns <NUM> remain relatively straight in the weave, and perpendicular to the weft yarns <NUM>, while the leno yarns <NUM> curve around the standard yarns <NUM>.

<FIG> illustrates an interlacing pattern corresponding to <FIG>, but in which alternate leno yarns <NUM> are point-drafted (e.g., a technique in which the leno yarns are drawn through heddles) such that adjacent leno yarns <NUM> have opposite lacing directions. <FIG> illustrates an interlacing pattern corresponding to <FIG>, but in which the leno yarns <NUM> are point-drafted such that adjacent leno yarns have opposite lacing directions.

<FIG> is a cross-sectional view of a plain leno weave structure taken through the weft yarns <NUM>.

<FIG> illustrates a representative leno weave as viewed from the reverse side of the fabric.

In a first representative example, an acute animal trial was conducted in which prosthetic heart valves including various skirts of the type shown in <FIG> were implanted in the aortic valves of sheep. A first prosthetic valve that was tested included a sealing member or skirt with a yarn density of <NUM> yarns per inch, in which the yarns had a fringe or filament density of <NUM> filaments per yarn. A second prosthetic valve had a skirt with a yarn density of <NUM> yarns per inch, in which the yarns had a filament density of <NUM> filaments per yarn. A prosthetic valve having no exterior skirt was also implanted as a control.

Prior to implantation, the prosthetic valves were partially crimped, and a stack of annuloplasty rings (e.g., two concentrically stacked annuloplasty rings) were attached around the exterior of the prosthetic valves by suturing. Each stack of annuloplasty rings had a plastic cable tie cinched around the bodies of the annuloplasty rings. The stacks of annuloplasty rings were attached to the prosthetic valves such that the heads of the cable ties were located between the outer skirt of the prosthetic valve and the bodies of the annuloplasty rings. In other words, the heads of the cable ties served to space the bodies of the annuloplasty rings away from the prosthetic valves such that an axially-extending channel was defined between the outer skirt and the annuloplasty rings on both sides of the cable tie head in order to induce paravalvular leakage past the prosthetic valves. For the control prosthetic valve without an exterior skirt, the head of the cable tie spaced the annuloplasty rings away from the exterior surface of the prosthetic valve frame.

The prosthetic valves were implanted in a surgical procedure. A baseline amount of paravalvular leakage through the space between the prosthetic valve frame and the stack of annuloplasty rings was determined using echocardiography and/or angiography while the patient was heparinized. Heparinization was then reversed (e.g., by administration of protamine sulfate), and paravalvular leakage was then assessed using echocardiography and angiography over a period of <NUM> to <NUM> minutes. The prosthetic valves were then surgically retrieved.

For the first prosthetic valve having the skirt with the yarn density of <NUM> yarns per inch, no paravalvular leakage was observed before or after heparin reversal. Upon explant, the space between the outer skirt and the attached annuloplasty rings had become completely sealed by thrombus formation, and the head of the cable tie had become at least partially encapsulated by one or more thrombi.

For the second prosthetic valve having the skirt with the yarn density of <NUM> yarns per inch, paravalvular leakage having an angiographic grade of <NUM>+ was observed by echocardiography, and a grade of <NUM>+ by angiography, before heparin reversal. As used herein, reference to "paravalvular leakage" or "regurgitation" graded at, e.g., <NUM>+, <NUM>+, <NUM>+, or <NUM>+ refers to the angiographic grading guidelines provided by the American Society of Echocardiography using assessment techniques including, for example, echocardiography, angiography, color flow Doppler, fluoroscopy, etc. (<NPL>). After heparin reversal, no paravalvular leakage was detected by either echocardiography or angiography. Upon explant, the space between the outer skirt and the attached annuloplasty rings had become completely sealed by thrombus formation, and the head of the cable tie had become at least partially encapsulated by one or more thrombi.

For both the first and second prosthetic valves including fringed skirts, the immediate acute reduction in paravalvular leakage may be attributable to interaction between blood and the yarn filaments. The continued gradual reduction in paravalvular leakage observed for the second prosthetic valve post-heparin reversal may be attributable to a continued cellular-level biological response resulting in thrombus formation and sealing. For the first prosthetic valve with the yarn density of <NUM> yarns per inch, the sealing of the space between the frame and the annuloplasty rings occurred nearly immediately. For the second prosthetic valve with the yarn density of <NUM> yarns per inch, the time to full closure or sealing of the space between the frame and the annuloplasty rings (e.g., no detectable paravalvular leakage) was <NUM> to <NUM> minutes.

For the control prosthetic valve that had no outer skirt, paravalvular leakage having a grade of <NUM>+ or greater was observed under heparinization. After heparin reversal, paravalvular leakage having an angiographic grade of <NUM>+ to <NUM>+ was observed. Upon explant, the space between the annuloplasty rings and the frame of the prosthetic valve was fully open or patent, and no appreciable biological sealing had occurred.

Any of the sealing element embodiments disclosed herein can be used in combination with any of the disclosed prosthetic heart valve and/or frame embodiments. A prosthetic heart valve can also include any of the sealing elements described herein, or portions thereof, in any combination.

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. " 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.

In the context of the present application, the terms "lower" and "upper" are used interchangeably with the terms "inflow" and "outflow", respectively. Thus, for example, in certain configurations the lower end of the valve is its inflow end and the upper end of the valve is its outflow end.

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.

Unless otherwise indicated, all numbers expressing quantities of components, molecular weights, percentages, temperatures, times, and so forth, as used in the specification or claims are to be understood as being modified by the term "about. " Accordingly, unless otherwise indicated, implicitly or explicitly, the numerical parameters set forth are approximations that can depend on the desired properties sought and/or limits of detection under test conditions/methods familiar to those of ordinary skill in the art. When directly and explicitly distinguishing embodiments from discussed prior art, the embodiment numbers are not approximates unless the word "about" is recited. Furthermore, not all alternatives recited herein are equivalents.

In some examples, values, procedures, or apparatus may be referred to as "lowest," "best," "minimum," or the like. It will be appreciated that such descriptions are intended to indicate that a selection among many alternatives can be made, and such selections need not be better, smaller, or otherwise preferable to other selections.

In the description, certain terms may be used such as "up," "down," "upper," "lower," "horizontal," "vertical," "left," "right," and the like. These terms are used, where applicable, to provide some clarity of description when dealing with relative relationships. But, these terms are not intended to imply absolute relationships, positions, and/or orientations. For example, with respect to an object, an "upper" surface can become a "lower" surface simply by turning the object over. Nevertheless, it is still the same object.

Claim 1:
An implantable prosthetic valve (<NUM>) that is radially collapsible to a collapsed configuration and radially expandable to an expanded configuration, the prosthetic valve (<NUM>) comprising:
an annular frame (<NUM>) having an inflow end (<NUM>), an outflow end (<NUM>), and a longitudinal axis;
a leaflet structure (<NUM>) positioned within the frame (<NUM>) and secured thereto; and
a sealing element (<NUM>) secured to the frame (<NUM>), the sealing element (<NUM>) comprising:
a plurality of first woven portions (<NUM>) configured as woven strips extending circumferentially around the frame (<NUM>);
a plurality of second woven portions (<NUM>) configured as woven strips extending circumferentially around the frame (<NUM>); and
a plurality of elastic, stretchable portions configured as floating yarn portions (<NUM>) extending circumferentially around the frame (<NUM>);
wherein the first woven portions (<NUM>), the second woven portions (<NUM>) and the floating yarn portions (<NUM>) are spaced apart from each other along the longitudinal axis of the frame (<NUM>);
wherein the first woven portions (<NUM>) comprise a weave pattern that is different from a weave pattern of the second woven portions (<NUM>).