Patent Description:
Prosthetic valves are used to replace natural valves in a cardiovascular system when the natural valve no longer functions properly. A flexible leaflet prosthetic valve comprises one or more leaflets that move under the influence of fluid pressure.

Prosthetic leaflets are attached to a support structure to form a valve. In operation, the flexible leaflets open when the inflow fluid pressure exceeds the outflow fluid pressure and close when the inflow fluid pressure drops below the outflow fluid pressure. The free edges of the leaflets coapt under the influence of outflow fluid pressure closing the valve to prevent outflow blood from flowing retrograde through the valve. <FIG> and <FIG> are perspective and axial views, respectively, of a closed prosthetic valve <NUM> that includes a frame <NUM> that supports leaflets <NUM>, in accordance to what is known in the art. The closed prosthetic valve <NUM> represents when the outflow pressure downstream of the prosthetic valve <NUM> is greater than the inflow pressure upstream of the prosthetic valve <NUM>, wherein the leaflets <NUM> close to prevent regurgitant flow through the prosthetic valve <NUM>.

<FIG> and <FIG> are a perspective view and axial view, respectively, of the prosthetic valve <NUM> where the leaflets <NUM> are open such as when the inflow pressure upstream of the prosthetic valve <NUM> is greater than the outflow pressure, wherein the leaflets <NUM> open to allow fluid to proceed in the forward flow direction <NUM> through the prosthetic valve <NUM>.

<FIG> are cross-sectional views of the closed prosthetic valve <NUM> of <FIG> along cutline 1E-1E and the open prosthetic valve <NUM> of <FIG> along cut line 1F--1F, respectively. <FIG> shows the retrograde flow direction <NUM> where the outflow pressure of the prosthetic valve <NUM> is greater than the inflow pressure thus closing the leaflet <NUM>. <FIG> shows the fluid moving in the forward flow direction <NUM> through the prosthetic valve <NUM> where the inflow pressure is greater than the outflow pressure thus opening the flexible leaflet <NUM> away from the valve axis X. Behind the leaflet <NUM> the fluid follows a recirculating direction, referred to as recirculating flow <NUM>, including flow in the retrograde flow direction <NUM> between the leaflet <NUM> and a structure behind the leaflet <NUM>, such as, but not limited to, the frame <NUM>, a prosthetic conduit, and native tissue.

The lack of or insufficient fluid in the retrograde flow direction <NUM> or recirculating flow <NUM> can result in the fluid flow slowing or stagnating behind the leaflet <NUM> and in particular, at the leaflet base <NUM> where the leaflet <NUM> intersects the frame <NUM>. The slowing or stagnation of fluid flow is known to cause the blood to clot and form thrombus. Thrombus is detrimental in that it can hinder the leaflet <NUM> opening and closing dynamics which in turn leads to increased pressure gradients that negatively affect valve performance. Thrombus may also flow downstream which can lead to stroke, heart attack or pulmonary embolism.

There remains a need for a prosthetic valve that reduces or eliminates the reduced or stagnated flow behind an open prosthetic valve leaflet.

<CIT> relates to a prosthetic valve for regulating fluid flow through a body vessel. The valve includes an expandable support frame and a valve leaflet and includes at least one opening that permits a controlled amount of retrograde flow through the valve when the valve is in a closed configuration.

Described embodiments are directed to apparatus, system, and methods for valve replacement, such as cardiac valve replacement. More specifically, described embodiments are directed toward flexible leaflet valve devices having biological or synthetic leaflet material and a support structure, and methods of making and implanting the valve devices. The present invention is disclosed in the appended claims.

According to one example (Example <NUM>), a valve comprises a leaflet moveable between an open position that permits antegrade flow through the prosthetic valve and a closed position that prevents regurgitant flow through the prosthetic valve, the leaflet comprising an aperture or gap, or a separation of portions of the leaflet to allow a flow or exchange of fluid between the front and back of the leaflet, when the leaflet is not in the closed position.

According to another example (Example <NUM>), further to Example <NUM>, the aperture, gap or separation is operable to close to prevent flow of exchange of fluid between the back and the front of the leaflet, when the leaflet is in the closed position.

According to another example (Example <NUM>), further to Examples <NUM> or <NUM>, further comprising a support structure, wherein the leaflet is coupled to the support structure.

According to another example (Example <NUM>), further to Examples <NUM> to <NUM>, the leaflet includes a first leaflet component and a second leaflet component.

According to another example (Example <NUM>), further to Example <NUM>, the first leaflet component is upstream of the second leaflet component, or the first leaflet component is downstream of the second leaflet component.

According to another example (Example <NUM>), further to Examples <NUM> or <NUM>, said flow or exchange of fluid is via an aperture, gap or separation of the first and second components when the leaflet is not in the closed position.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, and in accordance with Example <NUM>, the second leaflet component comprises an inflow free edge and defines a gap between the second leaflet component and the support structure.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, the first leaflet component or the second leaflet component defines an aperture therethrough, and wherein the other of the first leaflet component or the second leaflet component is operable to occlude the aperture.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, the first leaflet component and the second leaflet component partially overlap.

According to another example (Example <NUM>), further to Example <NUM>, the first leaflet component comprises a first overlap region and the second leaflet component comprises a second overlap region, wherein the first and second overlap regions are in sealing engagement with one another when the leaflet is in the closed position.

According to another example (Example <NUM>), further to Example <NUM>, the first and second overlap regions each extend from a free edge of the respective first and second leaflet component.

According to another example (Example <NUM>), further to Example <NUM>, the first overlap region extends from an outflow free edge of the first leaflet component and the second overlap region extends from an inflow free edge of the second leaflet component.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, the first leaflet component comprises apertures in the first overlap region, or wherein the second leaflet component comprises apertures in the second overlap region.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, the first leaflet component is stationary relative to the second leaflet component, or vice versa.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, and in accordance with Example <NUM>, the first leaflet component or the second leaflet component is stationary relative to the support structure.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, the first leaflet component is configured to move more slowly than the second leaflet component.

According to another example (Example <NUM>), further to Example <NUM>, the first leaflet component has a higher bending stiffness than the second leaflet component.

According to another example (Example <NUM>), further to any one of Examples <NUM> or <NUM>, the first leaflet component is upstream of the second leaflet component.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, the second leaflet component is configured to move more slowly than the first leaflet component.

According to another example (Example <NUM>), further to Example <NUM>, the second leaflet component has a higher bending stiffness than the first leaflet component.

According to another example (Example <NUM>), further to any one of Examples <NUM> or <NUM>, the second leaflet component is upstream of the first leaflet component.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, and in accordance with Example <NUM>, the first and second leaflet components overlap and define an overlap region which tapers in width towards the support structure.

According to another example (Example <NUM>), further to Example <NUM>, when the leaflet is in the closed position there is a regurgitant gap or gaps of a predetermined size between the first and second leaflet components extending away from the support structure.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, the leaflet comprises multiple apertures, gaps or separations of portions of the leaflet to allow a flow or exchange of fluid between the front and back of the leaflet when the leaflet is not in the closed position.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, the leaflet comprises multiple first leaflet components and/or wherein the leaflet comprises a first leaflet component comprising multiple outflow free edges.

According to another example (Example <NUM>), further to Example <NUM>, further includes a tether element which couples the multiple first leaflets or multiple outflow free edges to prevent prolapse.

According to another example (Example <NUM>), further to any one of Examples <NUM> or <NUM>, in further of example <NUM>, the second leaflet component comprises multiple inflow free edges defining multiple gaps between the second leaflet component and the support structure corresponding to one of the said multiple first leaflet components or outflow free edges.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, the second leaflet component defines multiple apertures therethrough, wherein the first leaflet component is operable to occlude the apertures, or wherein one said multiple first leaflet components is operable to occlude each said aperture.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, wherein the shape of the shape of the leaflet, and, and in further of Example <NUM>, the shape of a corresponding attachment region to a support structure, is generally that of a parabola or of an isosceles trapezoid.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, the leaflet comprises a porous polymer membrane and a material present in pores of the porous polymer membrane such that the or each leaflet is impermeable.

According to another example (Example <NUM>), further to Examples <NUM>, the porous polymer membrane is expanded polytetrafluoroethylene.

According to another example (Example <NUM>), further to any one of Examples <NUM> or <NUM>, the material present in the pores is an elastomer or an elastomeric material or a non-elastomeric material.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, the material present in the pores is a TFE/PMVE copolymer.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, the leaflet comprises a biological tissue.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, the leaflet comprises, when in further of any one of Examples <NUM> to <NUM>, wherein the or each first leaflet component and/or the second leaflet component comprises said porous polymer membrane and a material present in pores of the porous polymer membrane such that the or each first leaflet component and/or the second leaflet component is impermeable.

According to another example (Example <NUM>), further to Example <NUM>, wherein at least one of the first leaflet component and the second leaflet component comprises a biological tissue.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, the leaflet is coupled to a support structure in the form of a frame.

According to another example (Example <NUM>), further to Example <NUM>, the frame defines a generally open pattern of apertures operable to allow the frame to be compressed and expanded between different diameters.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, wherein the valve further comprises a plurality of leaflets.

According to another example (Example <NUM>), further to Example <NUM>, the valve may comprise three leaflets.

According to another example (Example <NUM>), further to any one of Examples <NUM> or <NUM>, wherein each leaflet comprises a leaflet free edge, wherein leaflet free edges may coapt under the influence of retrograde fluid pressure thereby closing the valve.

According to another example (Example <NUM>), further to any one of Examples <NUM> to <NUM>, wherein the valve is a prosthetic valve.

According to another example (Example <NUM>), further to Examples <NUM>, wherein the prosthetic valve is a prosthetic heart valve.

According to another example (Example <NUM>), a method of making a prosthetic valve, comprising: obtaining a support structure such as a leaflet frame or conduit, obtaining a leaflet including a first leaflet component and a second leaflet component; coupling the first leaflet component adjacent to an inlet portion of the support structure; and coupling the second leaflet component adjacent to an outlet portion of the support structure such that a second overlap region of a second inflow free edge of the second leaflet component overlaps a first overlap region of a first outflow free edge of the first leaflet component such that a portion of a second inflow side of the second leaflet component is in contact and in sealing engagement with a portion of a first outflow side of the first leaflet component when the leaflet is in a closed position defining a leaflet overlap region preventing fluid flow through a lumen in a retrograde direction, and wherein the first overlap region and the second overlap region are not in contact therewith wherein the first outflow free edge and the second inflow free edge define a gap therebetween when the leaflet is not in the closed position, wherein fluid adjacent a second outflow side can pass through the gap during fluid flow in a forward direction.

The foregoing examples are just that, and should not be read to limit or otherwise narrow the scope of any of the inventive concepts otherwise provided by the instant disclosure.

The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments described herein, and together with the description serve to explain the principles discussed in this disclosure.

Persons skilled in the art will readily appreciate that various aspects of the present disclosure can be realized by any number of methods and apparatus configured to perform the intended functions. Stated differently, other methods and apparatus can be incorporated herein to perform the intended functions. It should also be noted that the accompanying drawing figures referred to herein are not necessarily drawn to scale, but may be exaggerated to illustrate various aspects of the present disclosure, and in that regard, the drawing figures should not be construed as limiting.

Although the embodiments herein may be described in connection with various principles and beliefs, the described embodiments should not be bound by theory. For example, embodiments are described herein in connection with prosthetic valves, more specifically cardiac prosthetic valves. However, embodiments within the scope of this disclosure can be applied toward any valve or mechanism of similar structure and/or function. Furthermore, embodiments within the scope of this disclosure can be applied in non-cardiac applications.

The term "leaflet" as used herein in the context of prosthetic valves is a flexible component of a one-way valve wherein the leaflet is operable to move between an open and closed position under the influence of a pressure differential. In an open position, the leaflet allows blood to flow through the valve. In a closed position, the leaflet substantially blocks retrograde flow from passing through the valve. In embodiments comprising multiple leaflets, each leaflet cooperates with at least one neighboring leaflet to block the retrograde flow from becoming regurgitant. The pressure differential in the blood is caused, for example, by the contraction of a ventricle or atrium of the heart, or the drainage of blood from the ventricle or atrium. As the pressure on the inflow side of the valve rises above the pressure on the outflow side of the valve, the leaflets are caused to open and blood flows therethrough. As blood flows through the valve into a neighboring chamber or blood vessel, the pressure on the inflow side equalizes with the pressure on the outflow side. As the pressure on the inflow side of the valve drops below the pressure on the outflow side of the valve, the leaflets are caused to return to the closed position generally preventing regurgitant flow of blood through the valve.

As used herein, "inflow fluid pressure" refers to a fluid pressure at an upstream location of the valve. "Outflow fluid pressure" refers to a fluid pressure at a downstream location of the valve.

As used herein, "retrograde" and "retrograde flow" refers to fluid flow at a downstream location of the valve that is moving toward the valve. Retrograde flow may be encountered, by way of example, but not limited to, in turbulent or recirculatory flow that is downstream of the valve, and during the pressure transition of the inflow fluid pressure dropping below the outflow fluid pressure tending to change the flow pattern away from a forward flow direction.

As used herein, "regurgitant", "regurgitation", and "regurgitant flow" refers to flow through a valve when the leaflets are in the close position. A valve that is exhibiting regurgitation is commonly said to be leaking. Regurgitant flow is differentiated from retrograde flow in that regurgitant flow is fluid flow that passes through the valve from a downstream location to an upstream location whereas retrograde flow is flow in a downstream location that does not necessarily pass through the valve.

The term "biocompatible material" as used herein generically refers to any material with biocompatible characteristics including synthetic, such as, but not limited to, a biocompatible polymer, or a biological material, such as, but not limited to, human, bovine, and pig tissue.

The terms "native valve" orifice and "tissue orifice" refer to an anatomical structure into which a prosthetic valve can be placed. Such anatomical structure includes, but is not limited to, a location wherein a cardiac valve may have been surgically removed. It is understood that other anatomical structures that can receive a prosthetic valve include, but are not limited to, veins, arteries, ducts and shunts. It is further understood that a valve orifice or implant site may also refer to a location in a synthetic or biological conduit that may receive a valve.

As used herein, "couple" means to join, connect, attach, adhere, affix, or bond, whether directly or indirectly, and whether permanently or temporarily.

Embodiments herein include various apparatus, systems, and methods for a prosthetic valve, such as, but not limited to, cardiac valve replacement devices. The valve is operable as a one-way valve wherein the valve defines a valve orifice into which one or more flexible leaflets open to permit flow and close so as to occlude the valve orifice and prevent regurgitant flow in response to a differential fluid pressure. In accordance with embodiments, the leaflet is configured so as to increase the motion of fluid behind an open leaflet so as, but not limited to, reducing the likelihood of fluid stagnation and potential thrombus formation behind the open leaflet.

In accordance with embodiments, each of the one or more flexible leaflets comprise a means for allowing a flow or exchange of fluid between the front and back of the leaflet when the leaflet is not in the closed position through the leaflet via an aperture, gap or separation of portions of the leaflet. This flow or exchange of fluid may include fluid from in front of the leaflet passing through the leaflet to the back of the leaflet which displaces the existing fluid that is behind the leaflet and keeps that fluid in motion. This exchange of fluid may also include fluid from behind the leaflet passing through the leaflet to the front of the leaflet which displaces the existing fluid that is behind the leaflet and keeps it in motion.

In accordance with embodiments, a prosthetic valve includes at least one leaflet and a support structure supporting the leaflet so that it may operate as a one-way valve. As described in the embodiments presented below, the support structure is described as a frame and used herein as an example, and used interchangeably with support structure. It is understood that other support structures are anticipated, including, but not limited to, conduits, that are operable to support the leaflet for its intended function.

<FIG> and <FIG> are perspective and axial views, respectively, of a prosthetic valve <NUM> in a closed position, in accordance with an embodiment. <FIG> and <FIG> are perspective and axial views, respectively, of the prosthetic valve <NUM> in an open position, in accordance with an embodiment. <FIG> are cross-sectional views of the closed prosthetic valve <NUM> of <FIG> along cutline 2E-2E and of the prosthetic valve <NUM> of <FIG> along cutline 2F--2F, respectively.

As shown in <FIG>, a frame <NUM> is operable to hold and support a plurality of leaflets <NUM>. The frame <NUM> is annular, that is, it defines a cylinder having a lumen <NUM> having an axis X and a plurality of commissure posts <NUM> extending parallel to the axis X that are spaced from one another. Between the commissure posts <NUM> is a leaflet attachment region <NUM> that is operable to couple with and support the leaflet <NUM> about a perimeter of the leaflet <NUM> except for a leaflet free edge <NUM>.

The frame <NUM> defines a cylinder having a frame inner side <NUM> and a frame outer side <NUM> opposite the frame inner side <NUM>. The frame <NUM> further defines a plurality of commissure posts <NUM>.

Although the frame <NUM> in the instant embodiment defines a cylinder of constant diameter along the axis X, it is understood that the diameter may vary along the axis X. Such variation may be advantageous, such as, but not limited to, to better fit the anatomy of the tissue orifice and adjacent upstream and downstream anatomy. Similarly, the frame <NUM> may not necessarily be circular along the axis X but, by way of example, but not limited thereto, may be oval and lobed. Such variation may be advantageous, such as, but not limited to, to better fit the anatomy of the tissue orifice and adjacent upstream and downstream anatomy, and/or to control the flow dynamics through the valve and around the leaflets.

In accordance with an embodiment, the frame <NUM> is annular about a central longitudinal axis X of the prosthetic valve <NUM> as shown in <FIG>. The frame <NUM> has an inflow end <NUM> and an outflow end <NUM> opposite the inflow end <NUM> and defines a lumen <NUM> therebetween along an axis X. The frame <NUM> has at least one leaflet attachment region <NUM> for each leaflet <NUM>. The leaflet attachment region <NUM> has an inflow portion <NUM> and an outflow portion <NUM>.

The frame <NUM> can be etched, cut, laser cut, stamped, three-dimensional printed, among other suitable processes, into an annular structure or a sheet of material, with the sheet then formed into an annular structure. Wires and strands may also be used to form into an annular structure.

The frame <NUM> can comprise, such as, but not limited to, any metallic or polymeric material that is generally biocompatible. The frame <NUM> can comprise a shape-memory material, such as Nitinol, a nickel-titanium alloy. Other materials suitable for the frame <NUM> include, but not limited to, other titanium alloys, stainless steel, cobalt-nickel alloy, polypropylene, acetyl homopolymer, acetyl copolymer, other alloys or polymers, elastomers and elastomeric materials, other shape memory and/or superelastic materials, polymers, and composite materials, or any other material that is generally biocompatible having adequate physical and mechanical properties to function as a leaflet frame <NUM> as described herein. Suitable frames can be made from a variety of materials and need only be biocompatible or able to be made biocompatible.

It is appreciated that <FIG> shows a frame <NUM> that is operable to be used in a surgical procedure, wherein the frame <NUM> has a fixed diameter both pre- and post-implant. It is appreciated that the frame <NUM> may be configured for use in a transcatheter procedure, wherein the frame <NUM> can be expanded from a smaller pre-deployment diameter to a larger deployed diameter.

A wide variety of frames are known in the medical technology arts, and any suitable frame can be utilized. One requirement is that the frame provide a surface to which the leaflet can be attached and function as described herein.

As described below, in accordance with an embodiment, the frame has radially compressed and radially expanded configurations. Such a frame can be implanted at a point of treatment within a body vessel by minimally invasive techniques, such as delivery and deployment with an intravascular catheter. The frame can optionally provide additional function to the medical device. For example, the frame can provide a stenting function, i.e., exert a radially outward force on the interior wall of a vessel in which the medical device is implanted. By including a frame that exerts such a force, a medical device according to the invention can provide both a stenting and a valving function at a point of treatment within a body vessel.

The stent art provides numerous frames acceptable for use in the present invention, and any suitable stent can be used as the frame. The specific frame chosen will depend on numerous factors, including the body vessel in which the medical device is being implanted, the axial length of the treatment site within the vessel, the number of valves desired in the medical device, the inner diameter of the vessel, the delivery method for placing the medical device, and other considerations. Those skilled in the art can determine an appropriate frame based on these and other considerations.

The frame can be self-expandable or balloon expandable. The structural characteristics of both of these types of frames are known in the art, and are not detailed herein. Each type of frame has advantages and for any given application, one type may be more desirable than the other based on a variety of considerations. For example, in the peripheral vasculature, vessels are generally more compliant and typically experience dramatic changes in their cross-sectional shape during routine activity. Medical devices for implantation in the peripheral vasculature should retain a degree of flexibility to accommodate these changes of the vasculature. Accordingly, medical devices according to the invention intended for implantation in the peripheral vasculature, such as prosthetic venous valves, advantageously include a self-expandable frame. These frames, as is known in the art, are generally more flexible than balloon-expandable frames following deployment.

Suitable frames can also have a variety of shapes and configurations, including being comprised of wire, strands, braided strands, helically wound strands, ring members, consecutively attached ring members, zig-zag members, tubular members, and frames cut from solid tubes and flat sheets. Frames may define a generally open pattern of apertures operable to allow the frame to be compressed and expanded between different diameters, in accordance with embodiments.

As shown in <FIG>, the leaflet <NUM> is coupled to each of the at least one leaflet attachment region <NUM> of the frame <NUM>.

The leaflet <NUM> includes a first leaflet component <NUM> and a second leaflet component <NUM>, in accordance with an embodiment. The first leaflet component <NUM> has a first inflow side <NUM> and a first outflow side <NUM> opposite the first inflow side <NUM> that defines a first thickness. The term "inflow side" is that side which is facing the inflow end <NUM> of the frame <NUM> when the leaflet <NUM> is in the closed position. The term "outflow side" is that side which is facing the outflow end <NUM> of the frame <NUM> when the leaflet <NUM> is in the closed position. The first leaflet component <NUM> has a first frame attachment edge <NUM> and a first outflow free edge <NUM>.

The second leaflet component <NUM> has a second inflow side <NUM> and a second outflow side <NUM> opposite the second inflow side <NUM> defining a second thickness. The second leaflet component <NUM> has a plurality of second frame attachment edges <NUM>, a second inflow free edge <NUM> and a second outflow free edge <NUM> opposite the second inflow free edge <NUM>. The second leaflet component <NUM> is configured to be movable between an open position to allow fluid flow in a forward flow direction through the lumen <NUM> and a closed position in cooperative engagement with the first leaflet component <NUM> that prevents regurgitant flow.

The first frame attachment edge <NUM> of the first leaflet component <NUM> is coupled to the inflow portion <NUM> of the leaflet attachment region <NUM> with the first inflow side <NUM> facing the axis X. The inflow portion <NUM> is that portion adjacent to the inflow end <NUM> of the frame <NUM>.

The second frame attachment edges <NUM> of the second leaflet component <NUM> is coupled to the outflow portion <NUM> of the leaflet attachment region <NUM> with the second inflow side <NUM> facing the axis X. The outflow portion <NUM> is that portion adjacent to the outflow end <NUM> of the frame <NUM>.

The first leaflet component <NUM> and the second leaflet component are arranged on the frame <NUM> such that they at least partially overlap. A second overlap region <NUM> adjacent to the second inflow free edge <NUM> overlaps a first overlap region <NUM> adjacent to the first outflow free edge <NUM> such that a portion of the second inflow side <NUM> of the second leaflet component <NUM> is in contact and in sealing engagement with a portion of the first outflow side <NUM> of the first leaflet component <NUM> when the leaflet <NUM> is in the closed position defining a leaflet overlap region <NUM> operable to prevent regurgitant flow through the leaflet <NUM> at the leaflet overlap region <NUM>, as shown in <FIG>.

During fluid flow in the forward flow direction <NUM> when the leaflet <NUM> is not in the closed position, as shown in <FIG>, when the inflow pressure is greater than the outflow pressure, the first overlap region <NUM> and the second overlap region <NUM> move away from each other wherein the first outflow free edge <NUM> and the second inflow free edge <NUM> define a gap <NUM> therebetween. The gap <NUM> formed between the first leaflet component <NUM> and the second leaflet component <NUM> when the leaflet <NUM> is not in the closed position allows fluid adjacent the first outflow side <NUM> and the second outflow side <NUM> to pass through the gap <NUM> when the fluid is moving in the forward flow direction <NUM> through the lumen <NUM>. That is, recirculating flow <NUM> from behind the leaflet <NUM> may pass through the gap <NUM> preventing the recirculating flow <NUM> from stagnating behind the leaflet <NUM>. Further, the gap <NUM> also allows fluid flow in the forward flow direction <NUM> to pass through the gap <NUM> from the first inflow side <NUM> and the second inflow side <NUM> further disrupting and displacing the recirculating flow <NUM> behind the leaflet <NUM> to downstream of the leaflet <NUM>. Thus, blood behind the leaflet <NUM> is less likely to clot or form thrombus, particularly at the leaflet base <NUM> and where it attaches to the frame <NUM>.

In accordance with an embodiment, the first leaflet component <NUM> is stationary relative to the second leaflet component <NUM> such that the gap <NUM> may be formed between the second leaflet component <NUM> moving away from the first leaflet component <NUM> under fluid pressure during fluid flow in the forward flow direction <NUM>.

In accordance with another embodiment, the first leaflet component <NUM> has a bending stiffness that is greater than the second leaflet component <NUM> such that the second leaflet component <NUM> may move more quickly relative to the first leaflet component <NUM> such that the gap <NUM> may be formed between the second leaflet component <NUM> moving away from the first leaflet component <NUM> under fluid pressure during fluid flow in the forward flow direction <NUM>. Examples of providing a predetermined bending stiffness include, but not limited to, using a material having a predetermined modulus and providing a component of predetermined thickness.

In accordance with another embodiment, <FIG> and <FIG> are perspective and axial views, respectively, of a prosthetic valve <NUM> in a closed position. <FIG> and <FIG> are perspective and axial views, respectively, of the prosthetic valve <NUM> in an open position, in accordance with the embodiment of <FIG> and <FIG>. <FIG> are cross-sectional views of the closed prosthetic valve <NUM> of <FIG> along cutline 3E-3E and of the prosthetic valve <NUM> of <FIG> along cutline 3F--3F, respectively. The first overlap region <NUM> comprises a plurality of apertures <NUM> extending from the first inflow side <NUM> to the first outflow side <NUM> operable to allow upstream flow to pass through the apertures <NUM> from the first inflow side <NUM> to the first outflow side <NUM> during fluid flow in the forward flow direction <NUM> when the leaflet <NUM> is not in the closed position. The apertures <NUM> in the first overlap region <NUM> provides, in part, that the first leaflet component <NUM> moves to the open position at a slower rate than the second leaflet component <NUM> ensuring that the gap <NUM> is formed therebetween. During retrograde flow, the second overlap region <NUM> is in sealing engagement with the apertures <NUM> when the leaflet <NUM> is in the closed position preventing fluid flow through the apertures <NUM> in the retrograde flow direction <NUM>. Leakage of the fluid when the leaflet <NUM> is closed is known as regurgitation, or regurgitent flow.

In accordance with another embodiment, <FIG> and <FIG> are perspective and axial views, respectively, of a prosthetic valve <NUM> in a closed position. <FIG> and <FIG> are perspective and axial views, respectively, of the prosthetic valve <NUM> in an open position, in accordance with the embodiment of <FIG> and <FIG>. <FIG> are cross-sectional views of the closed prosthetic valve <NUM> of <FIG> along cutline 4E-4E and of the prosthetic valve <NUM> of <FIG> along cutline 4F--4F, respectively. The second overlap region <NUM> comprises a plurality of apertures <NUM> extending from the second inflow side <NUM> to the second outflow side <NUM> operable to allow fluid adjacent the second outflow side <NUM> to pass through the apertures <NUM> from the second outflow side <NUM> to the second inflow side <NUM> during fluid flow when the leaflet <NUM> is not in the closed position.

The apertures <NUM> in the second overlap region <NUM>, in part, augments the benefit of the gap <NUM> to further allow the flow of the fluid adjacent the second outflow side <NUM> to pass to the second inflow side <NUM>. During reverse flow, the second overlap region <NUM> is in sealing engagement with the apertures <NUM> when the leaflet <NUM> is in the closed position preventing fluid flow through the apertures <NUM> in the retrograde flow direction <NUM>, preventing regurgitation.

In the embodiments of <FIG>, <FIG>, and <FIG>, the leaflet overlap region <NUM> has a relatively uniform width. The first overlap region <NUM> and the second overlap region <NUM> defines a leaflet overlap region <NUM> that is relatively consistent in width from adjacent the frame <NUM> to away from the frame <NUM>. <FIG> is a perspective view of a prosthetic valve <NUM> wherein the leaflet overlap region <NUM> has a non-uniform width, in accordance with an embodiment. In the embodiment of <FIG>, the first overlap region <NUM> and the second overlap region <NUM> defines a leaflet overlap region <NUM> that tapers in width from a minimum adjacent the frame <NUM> to a maximum farthest away from the frame <NUM>. As shown in <FIG>, the leaflet overlap region <NUM> defines a width and a length, wherein the width has a non-uniform dimension along the width as defined by the first outflow free edge <NUM> having a concave profile. It is understood that the width of the overlap region <NUM>, as defined by the degree of overlap between first overlap region <NUM> and the second overlap region <NUM> is predetermined for, among other things, to prevent prolapse of the second inflow free edge <NUM> and to ensure a sufficient sealing engagement between the first overlap region <NUM> and the second overlap region <NUM> when the leaflet <NUM> is in the closed position to prevent regurgitant flow due to downstream fluid pressure. Under certain downstream fluid pressure conditions, the first overlap region <NUM> and the second overlap region <NUM> may slip relative to each other with the potential of slipping out of engagement, or prolapsing, if the overlap region <NUM> is not sufficiently wide. It is understood that the frame <NUM> and/or the leaflet <NUM> will elastically deform under fluid pressure. Further, it is understood that the elastic deformation at the first outflow free edge <NUM> and the second inflow free edge <NUM> may be greater away from the attachment point to the frame <NUM>. Therefore, the width of the overlap region <NUM> is predetermined to accommodate for the increase in deformation further away from the support provided by the frame <NUM>.

As will be described later in reference to the embodiment of <FIG>, the first overlap region <NUM> and the second overlap region <NUM> define a leaflet overlap region <NUM> that tapers in width such that there is no overlap between the first leaflet component <NUM> and the second leaflet component <NUM> adjacent to and a predetermined distance away from the frame <NUM> which defines a regurgitant gap <NUM> of a predetermined size.

It is also understood that the degree of overlap between first overlap region <NUM> and the second overlap region <NUM> will also affect the size of the gap <NUM> and the degree of separation between the first outflow free edge <NUM> and the second inflow free edge <NUM> when the leaflet <NUM> is not in the closed position.

The relative size of the first leaflet component <NUM> and the second leaflet component <NUM> is predetermined for a particular purpose. In accordance with an embodiment, the first leaflet component <NUM> is made relatively small so as to not excessively extend into the lumen <NUM> of the frame <NUM>, particularly if the first leaflet component <NUM> is relatively inflexible, so as to minimize the impediment to flow in the forward flow direction <NUM> through the prosthetic valve <NUM> when in the open position. It is understood that the relative size of the first leaflet component <NUM> and the second leaflet component <NUM> will determine, in part, the characteristics of the pattern of flow in the forward flow direction <NUM> and the pattern of flow in the recirculating direction, that is, recirculating flow <NUM>, which will also, in part, determine the dynamics of the first leaflet component <NUM> and the second leaflet component <NUM>. It has been found in some embodiments that as the first leaflet component <NUM> extends further into the lumen <NUM>, the second leaflet component <NUM> may begin to flutter when in the open position during forward flow conditions.

Related to the relative size of the first leaflet component <NUM> and the second leaflet component <NUM> is the axial location X1 of the overlap region <NUM> relative to the upstream-most location of the leaflet base <NUM>. In general, wherein the axial location X1 increases away from the inflow end <NUM> and closer to the outflow end <NUM>, the first leaflet component <NUM> will extend further into the lumen <NUM> of the frame <NUM> and thus affect the characteristics of the flow in the forward flow direction <NUM>.

The shape of the leaflets <NUM> are defined, at least in part, by the shape of the frame <NUM> at the leaflet attachment region <NUM> and the leaflet free edge <NUM>, as shown in <FIG>. In the embodiments of the prosthetic valve <NUM> shown in <FIG>, <FIG>, <FIG>, and <FIG>, the shape of the leaflet <NUM>, and corresponding leaflet attachment region <NUM> of the frame <NUM>, is substantially that of a parabola. The leaflet <NUM> may define a shape that is predetermined for a particular purpose. <FIG> is a perspective view of a prosthetic valve <NUM> having a frame <NUM> and a plurality of leaflets <NUM> each having a first leaflet component <NUM> and a second leaflet component <NUM> defining a shape substantially that of an isosceles trapezoid, in accordance with an embodiment. It has been found that leaflets <NUM> defining a shape substantially that of an isosceles trapezoid has improved bending dynamics as compared to that of a parabola. Improved bending dynamics of thin, flexible leaflets may include, but are not limited to, reduced creasing and wrinkling and faster opening and closing response to fluid pressure changes.

<FIG> is a perspective view of a prosthetic valve <NUM> having a frame <NUM> and a plurality of leaflets <NUM> each having a first leaflet component <NUM> and a second leaflet component <NUM> defining a shape substantially that of an isosceles trapezoid, in accordance with an embodiment. The first overlap region <NUM> and the second overlap region <NUM> define a leaflet overlap region <NUM> that tapers in width such that there is no overlap adjacent to and a predetermined distance away from the frame <NUM> defining a regurgitant gap <NUM> of a predetermined size. The regurgitant gap <NUM> allows a predetermined amount of retrograde flow to pass through the regurgitant gap <NUM> when the prosthetic valve <NUM> is closed. The regurgitant gap <NUM> is operable to prevent pinching or creasing of the first outflow free edge <NUM> and the second inflow free edge <NUM> at the frame attachment location adjacent the regurgitant gap when the leaflet <NUM> is in the closed position. Additionally, the regurgitant gap <NUM> may assist in preventing fluid stagnation at the location of the regurgitant gap <NUM> so at to prevent thrombus formation.

<FIG> is a plan view of a frame <NUM> unrolled to a flat profile to better visualize the shape of the frame components, in accordance with the embodiment of <FIG>. The frame <NUM> comprises a leaflet attachment region <NUM> that has substantially the shape of three sides of an isosceles trapezoid having two leaflet attachment sides <NUM>, and a leaflet attachment base <NUM>.

The leaflets <NUM> comprising the first leaflet component <NUM> and the second leaflet component <NUM> may be made in a number of different ways. In accordance with an embodiment, each leaflet <NUM> is made as a single pair including a first leaflet component <NUM> and a second leaflet component <NUM>. In accordance with another embodiment, as shown in <FIG>, a plurality of leaflets <NUM>, and in particular, a plurality of second leaflet components <NUM>, may be made from a single leaflet pattern. By way of example, a leaflet pattern comprising a plurality of leaflets can be made by starting with a cylinder of biological or synthetic material and cutting the cylinder into a pattern that defines the leaflets.

<FIG> is a plan view of a leaflet pattern <NUM> comprising a plurality of first leaflet components <NUM> and second leaflet components <NUM>, in accordance with an embodiment. The leaflet pattern <NUM> may be made from a flat sheet of material cut into a leaflet pattern <NUM> and subsequently rolled into a cylindrical shape or cut from a cylindrical component to correspond to the cylindrical shape of the frame <NUM>. In accordance with another embodiment, the leaflet pattern <NUM> may be formed is by compression or injection molding. The second leaflet components <NUM> may be linked together via second tabs <NUM>.

Referring to <FIG>, the first leaflet component <NUM> comprises a first frame attachment edge <NUM> and a first outflow free edge <NUM>. The first frame attachment edge <NUM> includes a plurality of first tabs <NUM> that couple to components of the frame <NUM> in a wrap-around fashion in accordance with an embodiment, as shown by way of example in <FIG>. The second leaflet component <NUM> comprises a second inflow free edge <NUM>, a second outflow free edge <NUM>, and second frame attachment edges <NUM>. The second frame attachment edge <NUM> includes a plurality of second tabs <NUM> that couple to components of the frame <NUM> in a wrap-around fashion.

Although some of the embodiments described herein provide, by way of example, attachment edges including tabs that couple to the frame, it is understood and appreciated that the leaflets may be coupled to the frame in many ways known in the art. By way of example, but not limited thereto, the leaflets may be coupled to the frame using mechanical elements, such as, but not limited to, those associated with posts, hooks, and suture, and using other means such as, but not limited to, heat bonding, gluing, molding and crimping. Embodiments presented herein are not limited by the particular coupling means used to couple the leaflet, and corresponding leaflet components, to the frame or other support structure.

As provided above, the shape of the leaflets <NUM> are defined, at least in part, by the shape of the frame <NUM> at the leaflet attachment region <NUM> and the leaflet free edge <NUM>. The shape of the leaflets <NUM> can also be defined by the processes used to manufacture the prosthetic valve <NUM>, such as, but not limited, those described below. For example, in accordance with an embodiment, the shape of the leaflets <NUM> depends in part on making the leaflets <NUM> using molding and trimming processes to impart a predetermined shape to the leaflets <NUM>.

<FIG> are plan views of a leaflet pattern <NUM> comprising a first leaflet component <NUM> and a second leaflet component <NUM>, respectively, in accordance with an embodiment. The first leaflet component <NUM> comprises a first frame attachment edge <NUM> and a first outflow free edge <NUM>. The first frame attachment edge <NUM> includes a plurality of first tabs <NUM> that are operable to couple to components of the frame <NUM> adjacent the leaflet attachment base <NUM> and at least a portion of the two leaflet attachment sides <NUM>, as shown in <FIG>, <FIG> and <FIG>. The first frame attachment edge <NUM> defines a shape of a portion of the leaflet sides <NUM> and the leaflet base <NUM>, in that the two leaflet sides <NUM> diverge from the leaflet base <NUM>. <FIG> shows two alternative embodiments for the leaflet base <NUM> in dashed lines, a straight first frame attachment edge 319a, corresponding to the frame <NUM> of <FIG>, and a parabolic first frame attachment edge 319b, suitable for a parabolic leaflet attachment base <NUM> corresponding to the frame <NUM> of <FIG>. During the opening and closing of the leaflet <NUM>, the first leaflet component <NUM> will bend about the leaflet base <NUM>. Bending about the straight first frame attachment edge 319a may be in a more controlled manner that may reduce wrinkling and/or fluttering of the first leaflet component <NUM> as compared with bending about the parabolic first frame attachment edge 319b.

The second leaflet component <NUM> comprises a second inflow free edge <NUM>, a second outflow free edge <NUM>, and two second frame attachment edges <NUM> that diverge from the second inflow free edge <NUM>. The second frame attachment edges <NUM> include a plurality of second tabs <NUM> that couple to components of the frame <NUM> adjacent each of the two leaflet attachment sides <NUM>. The first outflow free edge <NUM> of the first leaflet component <NUM> is operable to overlap the second inflow side <NUM> of the second inflow free edge <NUM> of the second leaflet component <NUM> to define an overlap region <NUM>, as shown in the embodiment of <FIG>, and similarly for the embodiment of <FIG>. The shape of the second inflow free edge <NUM> is predetermined by the shape of the first outflow free edge <NUM> and the desired width of the overlap region <NUM>, suitable for a particular purpose.

In accordance with embodiments, as exemplified in <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, wherein the second leaflet component <NUM> has a second inflow free edge <NUM> being not coupled to the leaflet attachment base <NUM> of the frame <NUM>, it has been found that the second leaflet component <NUM> has improved bending dynamics as compared to that of a parabolic leaflet <NUM> such as shown in <FIG>. The benefits of improved bending dynamics of the leaflet second component <NUM> may include, but are not limited to, reduced creasing and wrinkling, reduced fluttering, faster opening and closing response to fluid pressure changes, and an increase in durability.

In the previous embodiments, the first leaflet component <NUM> and the second leaflet component <NUM> are generally located upstream and downstream on the frame <NUM>, respectively, defining a single gap <NUM> generally extending across the leaflet <NUM> perpendicular to the axis X of the prosthetic valve <NUM>, as shown in <FIG>. It may be advantageous to provide a leaflet with more than one gap <NUM> for a predetermined flow dynamic behind the leaflet.

<FIG> is a perspective view a prosthetic valve <NUM> having a frame <NUM> and a plurality of leaflets <NUM> each having a plurality of first leaflet components <NUM> that overlap a second inflow side <NUM> of a second leaflet component <NUM>, in accordance with an embodiment. Similarly to the embodiment of <FIG>, a gap <NUM> formed between the first leaflet component <NUM> and the second leaflet component <NUM> when the leaflet <NUM> is not in the closed position allows fluid adjacent the first outflow side <NUM> and the second outflow side <NUM> to pass through the gap <NUM> during fluid flow in the forward flow direction <NUM> through the lumen <NUM>. That is, the recirculating flow <NUM> behind the leaflet <NUM> may pass through the gap <NUM> preventing the recirculating flow <NUM> from slowing down or stagnating behind the leaflet <NUM>. Further, the gap <NUM> also allows fluid flow in the forward flow direction <NUM> to pass through the gap <NUM> from the first inflow side <NUM> and the second inflow side <NUM> further disrupting and displacing the recirculating flow <NUM> behind the leaflet <NUM> to downstream of the leaflet <NUM>. Thus, fluid behind the leaflet <NUM> is less likely to clot or form thrombus, particularly at the leaflet base <NUM> and where it attaches to the frame <NUM>. In this embodiment, the first leaflet component <NUM> comprises a material with a high modulus such that it resists bending under the anticipated flow conditions. Since the first leaflet component <NUM> is not supported by the second leaflet component <NUM> at the overlap region <NUM> when in the closed position, the first leaflet component <NUM> must resist the back pressure of the fluid when in the closed position to prevent prolapse.

<FIG> and <FIG> are plan views of a leaflet pattern <NUM> comprising a plurality of first leaflet components <NUM> and second leaflet components <NUM>, respectively, in accordance with an embodiment. Referring to <FIG>, each of the first leaflet components <NUM> comprise a first frame attachment edge <NUM> and a first outflow free edge <NUM>. The first frame attachment edge <NUM> includes a plurality of first tabs <NUM> that couple to components of the frame <NUM>.

The second leaflet component <NUM> comprises a plurality of second inflow free edges <NUM>, a second outflow free edge <NUM>, and three second frame attachment edges <NUM>. The second frame attachment edges <NUM> include a plurality of first tabs <NUM> that couple to components of the frame <NUM>. Alignment of each of the first leaflet components <NUM> relative to the second leaflet component <NUM> is provided by locating first tab apertures <NUM> on first tabs <NUM> with second tab apertures <NUM> on second tabs <NUM>.

The leaflets <NUM> comprise multiple first leaflet components <NUM>, in this embodiment, two first leaflet components <NUM>, and a second leaflet component <NUM> defining two second inflow free edges <NUM>. The second leaflet component <NUM> is coupled to the frame <NUM> along second frame attachment edges <NUM>. A first leaflet component <NUM> is coupled to the frame <NUM> along the first frame attachment edge <NUM> adjacent each of the second inflow free edges <NUM> so as to define a gap <NUM> therebetween when the leaflet <NUM> is open. In accordance with an embodiment, the first outflow free edge <NUM> of the first leaflet component <NUM> is located adjacent to and overlaps the second inflow side <NUM> of the second inflow free edge <NUM> to define the overlap region <NUM>. Because of the specific location of the gap <NUM>, the gap <NUM> will close in sealing engagement at the overlap region <NUM>, shown in <FIG>, to prevent regurgitent flow when the leaflet <NUM> is in the closed position.

In accordance with the embodiment of <FIG>, the upstream-most second frame attachment edge 629a provides additional support to the second inflow free edges <NUM> such that they do not prolapse when in the closed position resisting downstream flow pressure. The length of the upstream-most second frame attachment edge 629a is sized for a particular purpose.

<FIG> is a perspective view a prosthetic valve <NUM> having a frame <NUM> and a plurality of leaflets <NUM> each having a plurality of first leaflet components <NUM> that overlap a second outflow side <NUM> of a second leaflet component <NUM>, in accordance with an embodiment. The first outflow free edge <NUM> of the first leaflet component <NUM> is located adjacent to and overlaps with the second outflow side <NUM> of the second inflow free edge <NUM> to define the overlap region <NUM>. The gap <NUM> will close in sealing engagement at the overlap region <NUM> to prevent regurgitent flow when the leaflet <NUM> is in the closed position. <FIG> is a cross-sectional view along cut-line 11C of the embodiment of <FIG> when the leaflet <NUM> is in the closed position. <FIG> is a cross-sectional view along cut-line 11C of the embodiment of <FIG> when the leaflet <NUM> is in the open position. A gap <NUM> formed between the first leaflet component <NUM> and the second leaflet component <NUM> when the leaflet <NUM> is not in the closed position allows fluid flow in the forward flow direction <NUM> to pass through the gap <NUM> from the first inflow side <NUM> and the second inflow side <NUM> disrupting and displacing the recirculating flow <NUM> behind the leaflet <NUM>. Thus, blood behind the leaflet <NUM> is less likely to clot or form thrombus, particularly at the leaflet base <NUM> and where it attaches to the frame <NUM>. Under certain flow conditions, the gap <NUM> also allows fluid adjacent the first outflow side <NUM> and the second outflow side <NUM> to pass through the gap <NUM> during fluid flow in the forward flow direction <NUM> through the lumen <NUM>. That is, the recirculating flow <NUM> behind the leaflet <NUM> may pass through the gap <NUM> preventing the recirculating flow <NUM> from slowing down or stagnating behind the leaflet <NUM>.

<FIG> is another embodiment of a first leaflet component <NUM> that may be used in cooperation with the second leaflet component <NUM> of <FIG>. The first leaflet component <NUM> comprises two a first frame attachment edges <NUM> and two first outflow free edges <NUM>. The first frame attachment edges <NUM> includes a plurality of first tabs <NUM> that couple to components of the frame <NUM>. This embodiment is similar to the embodiment of <FIG> wherein the two first leaflet components <NUM> are coupled together as one component.

<FIG> is another embodiment of a first leaflet component <NUM> that may be used in cooperation with the second leaflet component <NUM> of <FIG>. This embodiment is similar to the embodiment of <FIG> wherein the two first leaflet components <NUM> are coupled together as one component. The first leaflet component <NUM> comprises two a first frame attachment edges <NUM> and two first outflow free edges <NUM>. The first frame attachment edges <NUM> includes a plurality of first tabs <NUM> that couple to components of the frame <NUM>. The first leaflet component <NUM> further comprises a tether element <NUM> that couples the two first outflow free edges <NUM> to the frame via a plurality of first tabs <NUM>. The tether element <NUM> is operable to prevent prolapse of the two first outflow free edges <NUM> when the leaflets are in the closed position.

<FIG> is a perspective view a prosthetic valve <NUM> having a frame <NUM> and a plurality of leaflets <NUM> each having a plurality of first leaflet components <NUM> that overlap a second leaflet component <NUM>, in accordance with an embodiment. The second leaflet component <NUM> has a relatively narrow upstream-most second frame attachment edge 629a providing the benefit of providing relatively large gaps between the two first leaflet components <NUM> and the second leaflet component <NUM> when the leaflet is not in the closed position while providing tethered support of the second inflow free edges <NUM> that prevents prolapse when in the closed position resisting downstream flow pressure.

<FIG> is a perspective view a prosthetic valve <NUM> having a frame <NUM> and a plurality of leaflets <NUM> each having one first leaflet component <NUM> that overlaps a second leaflet component <NUM> that defines two second inflow free edges <NUM>, in accordance with another embodiment. The second leaflet component <NUM> is similar to the embodiment of <FIG> in that the second leaflet component <NUM> has a relatively narrow upstream-most second frame attachment edge 629a providing the benefit of providing relatively large gaps between the first leaflet component <NUM> and the second leaflet component <NUM> when the leaflet is not in the closed position while providing tethered support of the second inflow free edges <NUM> that prevents prolapse when in the closed position resisting downstream flow pressure.

It is appreciated that embodiments of the prosthetic valve having one or more first leaflet components and one or more second leaflet components, and where the overlap region is on the inflow side or outflow side of the second leaflet component, are predetermined for a particular purpose to provide flow through the gap therebetween when the leaflet is in the open position and to prevent regurgitent flow through the gap therebetween when the leaflet is in the closed position. The gap formed between the first leaflet component and the second leaflet component when the leaflet is not in the closed position allows fluid adjacent the first outflow side and the second outflow side to pass through the gap during fluid flow in the forward direction through the lumen. That is, the recirculating flow behind the leaflet may pass through the gap <NUM> preventing the recirculating flow from slowing down or stagnating behind the leaflet. Further, the gap also allows forward flow to pass through the gap from the first inflow side and the second inflow side further disrupting and displacing the recirculating flow behind the leaflet to downstream of the leaflet. Thus, blood behind the leaflet is less likely to clot or form thrombus, particularly where the leaflet attaches to the frame.

In accordance with another embodiment, as shown in <FIG>, a prosthetic valve <NUM> comprises a leaflet <NUM> having a second leaflet component <NUM> defining a second leaflet aperture <NUM> therethrough and a first leaflet component <NUM> operable to close the second leaflet aperture <NUM> when the leaflet <NUM> is in the closed position. <FIG> and <FIG> are perspective and axial views, respectively, of a prosthetic valve <NUM> in a closed position, in accordance with an embodiment. <FIG> and <FIG> are perspective and axial views, respectively, of the prosthetic valve <NUM> in an open position, in accordance with an embodiment. <FIG> are cross-sectional views of the closed prosthetic valve <NUM> of <FIG> along cutline 16E-16E and of the prosthetic valve <NUM> of <FIG> along cutline 16F-16F, respectively.

As shown in <FIG>, a frame <NUM> is operable to hold and support a plurality of leaflets <NUM>. The frame <NUM> is annular, that is, it defines a cylinder having a lumen <NUM> having an axis X and a plurality of commissure posts <NUM> extending parallel to the axis X that are spaced from one another. Between the commissure posts <NUM> is a leaflet attachment region <NUM> that is operable to couple with and support the leaflet <NUM> about a perimeter of the leaflet <NUM>.

The leaflet <NUM> includes a first leaflet component <NUM> and a second leaflet component <NUM>, in accordance with an embodiment. The first leaflet component <NUM> has a first inflow side <NUM> and a first outflow side <NUM> opposite the first inflow side <NUM> that defines a first thickness. The first leaflet component <NUM> has a first frame attachment edge <NUM> and a first outflow free edge <NUM>. The first leaflet component <NUM> defines a second leaflet aperture <NUM> adjacent the leaflet base <NUM>.

The second leaflet component <NUM> has a second inflow side <NUM> and a second outflow side <NUM> opposite the second inflow side <NUM> defining a second thickness. The second leaflet component <NUM> has a plurality of second frame attachment edges <NUM> and an aperture occluder <NUM> therebetween that is operable to occlude the second leaflet aperture <NUM> when the leaflet <NUM> is in the closed position. The first leaflet component <NUM> and the second leaflet component <NUM> are configured to be movable between an open position to allow fluid flow in a forward flow direction through the lumen <NUM> and a closed position in cooperative engagement that prevents regurgitant flow.

During fluid flow in the forward flow direction <NUM> when the leaflet <NUM> is not in the closed position, as shown in <FIG>, when the inflow pressure is greater than the outflow pressure, the first overlap region <NUM> and the second overlap region <NUM> move away from each other wherein the first leaflet component <NUM> uncovers the second leaflet aperture <NUM> allowing fluid to flow therethrough. The second leaflet aperture <NUM> in the second leaflet component <NUM> when the leaflet <NUM> is not in the closed position allows fluid adjacent the second inflow side <NUM> to pass through the second leaflet aperture <NUM> when the fluid is moving in the forward flow direction <NUM> through the lumen <NUM>. The aperture occluder <NUM> to move downstream from the second leaflet aperture <NUM>. Recirculating flow <NUM> from behind the leaflet <NUM>, including the first leaflet component <NUM> may pass in front of the aperture occluder <NUM> so as to prevent the recirculating flow <NUM> from stagnating behind the leaflet <NUM>. Thus, blood behind the leaflet <NUM> is less likely to clot or form thrombus, particularly at the leaflet base <NUM> and where it attaches to the frame <NUM>.

In accordance with some embodiments herein, the leaflet <NUM> can comprise a biocompatible material that is not of a biological source and that is sufficiently compliant and strong for the particular purpose, such as a biocompatible polymer. In accordance with some embodiments, the first leaflet component <NUM> and the second leaflet component <NUM> comprise the same material and exhibit the same material properties. In accordance with other embodiments, the first leaflet component <NUM> has a bending stiffness that is greater than the second leaflet component <NUM>. Examples of providing a predetermined bending stiffness include, but not limited to, using a material having a predetermined modulus and providing a component of predetermined thickness.

In an embodiment, the leaflet <NUM> comprises a membrane that is combined with an elastomer or elastomeric material to form a composite material. In accordance with other embodiments, the biocompatible material that makes up the leaflet <NUM> comprises a biological material, such as, but not limited to, human, bovine, and pig tissue.

The leaflet <NUM> can comprise any biocompatible material sufficiently compliant and flexible, such as a biocompatible polymer. Either one or both of the first leaflet component <NUM> and the second leaflet component <NUM> can comprise a membrane that is combined with an elastomer or elastomeric material to form a composite material. The leaflet <NUM> can comprise, according to an embodiment, a composite material comprising an expanded fluoropolymer membrane, which comprises a plurality of spaces within a matrix of fibrils, and an elastomeric material. It should be appreciated that multiple types of fluoropolymer membranes and multiple types of elastomeric materials can be combined to form a composite material while remaining within the scope of the present disclosure. It should also be appreciated that the elastomeric material can include multiple elastomers, multiple types of non-elastomeric components, and include such things as inorganic fillers, therapeutic agents, radiopaque markers, and the like while remaining within the scope of the present disclosure.

In accordance with an embodiment, the composite material includes an expanded fluoropolymer material made from porous ePTFE membrane, for instance as generally described in <CIT> to Bacino.

The expandable fluoropolymer, used to form the expanded fluoropolymer material described, can comprise PTFE homopolymer. In alternative embodiments, blends of PTFE, expandable modified PTFE and/or expanded copolymers of PTFE can be used. Non-limiting examples of suitable fluoropolymer materials are described in, for example, <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>.

The expanded fluoropolymer membrane can comprise any suitable microstructure, such as pores, for achieving the desired leaflet performance. Other biocompatible polymers which can be suitable for use in leaflet include but are not limited to the groups of urethanes, silicones (organopolysiloxanes), copolymers of silicon-urethane, styrene/isobutylene copolymers, polyisobutylene, polyethylene-co-poly(vinyl acetate), polyester copolymers, nylon copolymers, fluorinated hydrocarbon polymers and copolymers or mixtures of each of the foregoing.

In accordance with embodiments, the first leaflet component and the second leaflet component may be formed of at least one of Polyether ether ketone (PEEK), expanded Polytetrafluoroethylene (ePTFE), Fluorinated ethylene propylene (FEP), copolymers of tetrafluoroethylene (TFE) and perfluoromethyl vinyl ether (PMVE) (TFE-PMVE copolymer), urethanes, polyimides, thermoplastics, thermosets, 3D printable metals and polymers (stainless steel, titanium, etc.) nylon, or any other biocompatible material suitable for long term blood contact that is dimensionally stable, and does not leech contaminates.

Further examples of leaflet construct materials include: wherein the leaflet construct comprises at least one fluoropolymer membrane layer; wherein the leaflet construct comprises a laminate having more than one fluoropolymer membrane layer; wherein the at least one fluoropolymer membrane layer is an expanded fluoropolymer membrane layer; wherein an elastomer, elastomeric, non-elastomer, or a copolymer of TFE-PMVE material is contained within the expanded fluoropolymer membrane layer; wherein the elastomer or elastomeric material comprises perfluoromethyl vinyl ether and tetrafluoroethylene; wherein the expanded fluoropolymer membrane layer comprises ePTFE; wherein the leaflet construct comprises a composite material having at least one fluoropolymer membrane layer having a plurality of pores and an elastomer or elastomeric material present in the pores of at least one of the fluoropolymer membrane layers; wherein the composite material comprises fluoropolymer membrane by weight in a range of about <NUM>% to <NUM>%; wherein the elastomer comprises (per)fluoroalkylvinylethers (PAVE); wherein the elastomer or elastomeric material comprises a copolymer of tetrafluoroethylene and perfluoromethyl vinyl ether; wherein the elastomer is silicone; wherein the elastomer is a fluoroelastomer; wherein the elastomer is a urethane; and wherein the elastomer or elastomeric material is a TFE/PMVE copolymer; wherein the TFE/PMVE copolymer comprises essentially of between about <NUM> and <NUM> weight percent perfluoromethyl vinyl ether and complementally <NUM> and <NUM> weight percent tetrafluoroethylene; and wherein the leaflet construct comprises silicone.

The leaflet comprises a section of material, such as a sheet, that is attached to the frame. The leaflet can be formed of any suitable material, and need only be biocompatible or be able to be made biocompatible. The material can advantageously be formed of a flexible material. Examples of suitable materials for the valve leaflet include natural materials, synthetic materials, and combinations of natural and synthetic materials. Examples of suitable natural materials include extracellular matrix (ECM) materials, such as small intestine submucosa (SIS), and other bioremodellable materials, such as bovine pericardium. Other examples of ECM materials that can be used in the prosthetic valves of the invention include stomach submucosa, liver basement membrane, urinary bladder submucosa, tissue mucosa, and dura mater. Examples of suitable synthetic materials include polymeric materials, such as expanded polytetrafluoroethylene and polyurethane. ECM materials are particularly well-suited materials for use in the leaflet, at least because of their abilities to remodel and become incorporated into adjacent tissues. These materials can provide a scaffold onto which cellular in-growth can occur, eventually allowing the material to remodel into a structure of host cells.

In accordance with an embodiment, the first leaflet component and the second leaflet component comprise a porous polymer membrane and an elastomeric material present in pores of the porous polymer membrane such that the first leaflet component and the second leaflet components are impermeable. Further, in another embodiment, the porous polymer membrane is expanded polytetrafluoroethylene. Further, in another embodiment, the elastomeric material is an elastomer. Further, in another embodiment, the elastomeric material is TFE/PMVE copolymer. Further, in another embodiment, the elastomer is TFE/PMVE copolymer.

In accordance with an embodiment, the first leaflet component and the second leaflet component comprise a porous polymer membrane and an elastomer present in pores of the porous polymer membrane such that the first leaflet component and the second leaflet components are impermeable. Further, in another embodiment, the porous polymer membrane is expanded polytetrafluoroethylene. Further, in another embodiment, the elastomer is TFE/PMVE copolymer.

In accordance with an embodiment, the first leaflet component or the second leaflet component comprise a porous polymer membrane and an elastomeric material present in pores of the porous polymer membrane such that the first leaflet component or the second leaflet component, respectively, is impermeable.

In accordance with an embodiment, the first leaflet component and the second leaflet component comprise expanded polytetrafluoroethylene membrane and TFE/PMVE copolymer present in pores of the expanded polytetrafluoroethylene membrane such that the first leaflet component and the second leaflet component, respectively, are impermeable.

In accordance with an embodiment, at least one of the first leaflet component and the second leaflet component comprise a biological tissue.

In accordance with an embodiment, a prosthetic valve comprises a frame and a plurality of leaflets each including one or more first valve components that overlap a second valve component. The frame includes an inflow end and an outflow end and leaflet attachment portions. Each first leaflet component includes a first inflow end portion and a first outflow end portion wherein the first inflow end portion is coupled to a leaflet attachment portion adjacent the inflow end of the frame. The second leaflet portion has a second inflow end portion, a second outflow end portion, a plurality of side attachment portions, a lumen facing side and a frame facing side. At least two side attachment portions are coupled to the leaflet attachment portions of the frame. A portion of the first leaflet outflow end portion overlaps with a portion of the second leaflet inflow end portion of the leaflet on the lumen facing side defining an overlap region. The leaflet being movable between an open position to allow fluid flow in a forward direction through the lumen and a closed position in cooperative engagement with the valve component in sealing engagement at the overlap region that prevents fluid flow in a retrograde direction through the frame. A gap is formed between the overlap region to allow fluid flow therethrough during fluid flow in a forward direction through the frame.

In accordance with another embodiment, a prosthetic valve comprises a first leaflet component and a second leaflet component. The second leaflet component being disposed downstream of the first leaflet component. The first leaflet component and the second leaflet component are in operable engagement configured to allow forward fluid flow through the prosthetic valve in a first direction extending downstream and prevent retrograde fluid flow through the prosthetic valve in an opposite direction extending upstream, and in operable engagement configured to allow fluid flow between a gap defined by the first leaflet component and the second leaflet component during forward fluid flow through the prosthetic valve.

In accordance with another embodiment, a prosthetic valve comprises a frame and a leaflet component coupled to the frame being moveable between a first position that permits fluid to forward flow in a first direction through the prosthetic valve and a second position that hinders retrograde flow in a second direction opposite the first direction through the prosthetic valve. The leaflet component includes a means for opening an aperture during forward flow to enable fluid flow therethrough during forward flow and to close the aperture during retrograde flow.

In accordance with another embodiment, a prosthetic valve, comprises a frame and a leaflet coupled to the frame being moveable between a first position that permits antegrade flow through the prosthetic valve and a second position that prevents retrograde flow through the prosthetic valve. The leaflet component includes a recirculation aperture operable to open to enable recirculation flow therethrough during antegrade flow through the prosthetic valve and operable to close to prevent retrograde flow therethrough through the prosthetic valve.

In accordance with another embodiment, a prosthetic valve comprises a frame, a first leaflet component coupled to the frame, and a second leaflet component coupled to the frame and at least partially overlapping the first leaflet component defining an overlap region. The second leaflet component being moveable between a first position that brings the first leaflet component and the second leaflet component into sealing engagement at the overlap region that prevents retrograde flow through the prosthetic valve and moveable between a second position that allows antegrade flow through the prosthetic valve and separates the first leaflet component and the second leaflet component at the overlap region defining a recirculation aperture that allows recirculation flow through the recirculation aperture.

In accordance with another embodiment, a prosthetic valve comprises a frame and at least one leaflet. The frame has an inflow end and an outflow end opposite the inflow end and defining a lumen therebetween defining an axis, the frame having at least one leaflet attachment region having an inflow portion and an outflow portion. A leaflet is coupled to each of the at least one leaflet attachment regions. Each leaflet includes at least one first leaflet component and a second leaflet component. Each first leaflet component has a first inflow side and a first outflow side opposite the first inflow side, a first frame attachment edge and a first outflow free edge. The second leaflet component has a second inflow side and a second outflow side opposite the second inflow side. The second leaflet component has a plurality of second frame attachment edges, at least one second inflow free edge and a second outflow free edge opposite the at least one second inflow free edge. The second leaflet component being movable between an open position to allow fluid flow in a forward direction through the lumen and a closed position in cooperative engagement with the at least one first leaflet component that prevents fluid flow in a retrograde direction through the lumen. The first frame attachment edge of the at least one first leaflet component being coupled to the inflow portion of the leaflet attachment region with the first inflow side facing the axis. The frame attachment edges of the second leaflet component being coupled to at least the outflow portion of the leaflet attachment region with the second inflow side facing the axis. Wherein a second overlap region of the second inflow free edge overlaps a first overlap region of the first outflow free edge of the at least one first leaflet component when the leaflet is in the closed position defining a leaflet overlap region preventing fluid flow through the lumen in the retrograde direction. Wherein the first overlap region of the at least one first leaflet component and the second overlap region are not in contact therewith wherein the first outflow free edge of the at least one first leaflet component and the second inflow free edge define a gap therebetween when the leaflet is not in the closed position, wherein fluid adjacent the second outflow side can pass through the gap during fluid flow in the forward direction.

In accordance with another embodiment, a prosthetic valve comprises a frame and a plurality of leaflets. The frame has an inflow end and an outflow end opposite the inflow end and defines a lumen therebetween defining an axis. The frame has at least one leaflet attachment region having an inflow portion and an outflow portion. Each leaflet being coupled to each of the at least one leaflet attachment regions. The at least one leaflet includes at least one first leaflet component and a second leaflet component. The at least one first leaflet component has a first inflow side and a first outflow side opposite the first inflow side. The at least one first leaflet component has a first frame attachment edge and a first outflow free edge, The second leaflet component has a second inflow side and a second outflow side opposite the second inflow side. The second leaflet component has a plurality of second frame attachment edges, at least one second inflow free edge and a second outflow free edge opposite the at least one second inflow free edge. The second leaflet component being movable between an open position to allow fluid flow in a forward direction through the lumen and a closed position in cooperative engagement with the at least one first leaflet component that prevents fluid flow in a retrograde direction through the lumen. The first frame attachment edge of each first leaflet component being coupled to the inflow portion of the leaflet attachment region with the first inflow side facing the axis. The frame attachment edges of the second leaflet component being coupled to at least the outflow portion of the leaflet attachment region with the second inflow side facing the axis. Wherein a second overlap region of the second leaflet component adjacent the second inflow free edge overlaps a first overlap region of the first leaflet component adjacent the first outflow free edge such that they are in sealing engagement therewith when the leaflet is in the closed position defining a leaflet overlap region preventing fluid flow through the lumen in the retrograde direction. Wherein the first overlap region of each first leaflet component and the second overlap region are not in contact therewith wherein the first outflow free edge of the each of the first leaflet component and the second inflow free edge define a gap therebetween when the leaflet is not in the closed position, wherein fluid adjacent the second outflow side can pass through the gap during fluid flow in the forward direction.

In accordance with embodiments, the valve may comprise the following properties, singularly or in combination.

The leaflet may comprise a means for allowing a flow or exchange of fluid between the front and back of the leaflet when the leaflet is not in the closed position. Said flow or exchange of fluid may be through the leaflet via an aperture, gap or separation of portions of the leaflet. Said aperture, gap or separation may be operable to close to prevent flow of exchange of fluid between the back and the front of the leaflet, when the leaflet is in the closed position.

The valve may comprise a support structure, such as a frame or a conduit; wherein the leaflet is coupled to the support structure.

The leaflet may include a first leaflet component and a second leaflet component.

The first leaflet component and the second leaflet component may be coupled to the support structure.

The first leaflet component may be upstream of the second leaflet component.

The first leaflet component may be downstream of the second leaflet component.

Said flow or exchange of fluid may be via an aperture, gap or separation of the first and second components, when the leaflet is not in the closed position.

In some embodiments, the second leaflet component comprises an inflow free edge, and defines a gap between the second leaflet component and the support structure. In some embodiments, the first leaflet component or the second leaflet component defines an aperture therethrough, and wherein the other of the first leaflet component or the second leaflet component is operable to occlude the aperture.

The first leaflet component and the second leaflet component may be partially overlapping.

Respective first and second overlap regions of the first leaflet component and the second leaflet component may be in sealing engagement with one another, when the leaflet is in the closed position. The first leaflet component may comprise a first overlap region and the second leaflet component may comprise a second overlap region, wherein the first and second overlap regions together define a leaflet overlap region, when the first and second leaflet components are in sealing engagement with one another.

The first and second overlap regions may extend from a free edge of the respective leaflet component.

The first overlap region may extend from, and typically upstream from, an outflow free edge. The second overlap region may extend from, and typically downstream from, an inflow free edge.

The first and second leaflet components may be brought into sealing engagement with one another by fluid pressure, under the action of retrograde flow.

The first leaflet component may be stationary relative to the second leaflet component, or vice versa. The first leaflet component, or the second leaflet component may be relatively stationary relative to the support structure.

The first leaflet component may be configured to move more slowly than the second leaflet component, or vice versa. In some embodiments, the first leaflet component is downstream of the second leaflet component and the second leaflet component is configured to move more slowly than the first leaflet component. In some embodiments the first leaflet component is upstream of the second leaflet component and the first leaflet component is configured to move more slowly than the second leaflet component.

In some embodiments, the first leaflet component may have a higher, or a lower, bending stiffness than the second leaflet component.

The first leaflet component may comprise apertures in the first overlap region. In some embodiments, the second leaflet component may comprise apertures in the second overlap region. During forward flow (i.e. downstream flow) the apertures in the first or second overlap region may provide, at least in part, that the respective first or second leaflet component moves to the open position at a slower rate than the other said leaflet component, such that a gap is formed therebetween.

In some embodiments, apertures are provided in the first or second overlap regions to augment regurgitant blood flow. In some embodiments, the leaflet component configured to move more slowly is provided with apertures in its overlap region. In some embodiments, the leaflet component configured to move more quickly is provided with apertures in its overlap region.

The apertures in the first or second overlap region may be sealed by the other said overlap region, during retrograde blood flow when the leaflet is in the closed position.

The leaflet overlap region may be of any suitable shape or configuration. In some embodiments, the leaflet overlap regions tapers in width towards the support structure. For example, in some embodiments there is no overlap at and optionally to a predetermined distance away from the support structure.

In some embodiments, when the leaflet is in the closed position, there is a regurgitant gap or gaps of a predetermined size between the first and second leaflet components, for example extending away from the support structure. The regurgitant gap or gaps allow a predetermined amount of retrograde flow to pass therethrough, when the valve is closed.

The relative sizes of the first and second leaflet components may determine the axial location of the leaflet overlap region.

The leaflet may provide for flow or exchange of fluid may be via multiple (e.g. two, or three or more) apertures, gaps or separations, when the leaflet is not in the closed position.

The leaflet may comprise multiple first leaflet components. The leaflet may comprise a first leaflet component comprising multiple outflow free edges.

In some embodiments, the second leaflet component may comprise multiple inflow free edges, defining multiple gaps between the second leaflet component and the support structure, corresponding to one of the said multiple first leaflet components or free edges.

In some embodiments, the second leaflet component defines multiple apertures therethrough. The first leaflet component may be operable to occlude the apertures, or one of the said multiple first leaflet components may be operable to occlude each said aperture.

Where there are multiple outflow free edges (either of multiple first leaflet components or of a first leaflet component having multiple outflow free edges), the leaflet may comprise a tether element, which couples said outflow free edges. The tether element may prevent prolapse.

The leaflet may comprises a porous polymer membrane and a material present in pores of the porous polymer membrane such that the or each leaflet is impermeable.

The porous polymer membrane may for example be a fluoropolymer such as expanded polytetrafluoroethylene, or may be a polymer such as polyethylene.

The material present in the pores may be an elastomer or an elastomeric material or may be a non-elastomeric material. The material present in the pores may be a TFE/PMVE copolymer.

The leaflet may alternatively or in addition comprise a biological tissue, such as native valve tissue, or porcine tissue.

Where the valve comprises one or more first leaflet components and a second leaflet component, the or each first leaflet component and/or the second leaflet component may comprise said porous polymer membrane and a material present in pores of the porous polymer membrane such that the or each first leaflet component and/or the second leaflet component is impermeable.

In some embodiments, wherein at least one of the first leaflet component (or components) and the second leaflet component comprises a biological tissue.

The leaflet may have any suitable shape or configuration. For example, the shape of the leaflet, and of a corresponding attachment region to a support structure, may be generally that of a parabola or of an isosceles trapezoid.

The valve may comprise a plurality of leaflets, for example two leaflets, three leaflets or four leaflets. The valve may comprise three leaflets.

Each leaflet may comprise a leaflet free edge. The leaflet free edges may coapt under the influence of outflow (i.e. retrograde) fluid pressure; thereby closing the valve.

The valve may be a prosthetic valve. The valve may be a prosthetic heart valve.

The valve may comprise a leaflet including a first leaflet component and a second leaflet component being disposed downstream of the first leaflet component, the first leaflet component and the second leaflet component are in operable engagement configured to allow forward fluid flow through the prosthetic valve in a first direction extending downstream and prevent regurgitant fluid flow through the prosthetic valve in an opposite direction extending upstream, and in operable engagement configured to allow fluid flow between a gap defined by the first leaflet component and the second leaflet component during forward fluid flow through the prosthetic valve.

The valve may comprise a frame; and a leaflet including a first leaflet component coupled to the frame and a second leaflet component coupled to the frame and at least partially overlapping the first leaflet component defining an overlap region, the second leaflet component being moveable between a first position that brings the first leaflet component and the second leaflet component into sealing engagement at the overlap region that prevents regurgitant flow through the prosthetic valve and moveable between a second position that allows antegrade flow through the prosthetic valve and separates the first leaflet component and the second leaflet component at the overlap region defining a recirculation aperture that allows recirculation flow through the recirculation aperture.

The valve may comprise a frame; and a leaflet including a leaflet component coupled to the frame being moveable between a first position that permits fluid to forward flow in a first direction through the prosthetic valve and a second position that hinders regurgitant flow in a second direction opposite the first direction through the prosthetic valve, the leaflet component including a means for opening an aperture during forward flow to enable fluid flow therethrough during forward flow and to close the aperture during retrograde flow.

The valve may comprise a frame; and a leaflet coupled to the frame being moveable between a first position that permits antegrade flow through the prosthetic valve and a second position that prevents regurgitant flow through the prosthetic valve, the leaflet including a recirculation aperture operable to open to enable recirculation flow therethrough during antegrade flow through the prosthetic valve and operable to close to prevent retrograde flow therethrough through the prosthetic valve.

A method for treating a human patient with a diagnosed condition or disease associated with valve insufficiency or valve failure of a native valve, the method comprising implanting a prosthetic valve at the location of the native valve. The prosthetic valve comprises a frame and a plurality of leaflets. The frame has an inflow end and an outflow end opposite the inflow end and defines a lumen therebetween defining an axis. The frame has at least one leaflet attachment region having an inflow portion and an outflow portion. Each leaflet being coupled to each of the at least one leaflet attachment regions. The at least one leaflet includes at least one first leaflet component and a second leaflet component. The at least one first leaflet component has a first inflow side and a first outflow side opposite the first inflow side. The at least one first leaflet component has a first frame attachment edge and a first outflow free edge, The second leaflet component has a second inflow side and a second outflow side opposite the second inflow side. The second leaflet component has a plurality of second frame attachment edges, at least one second inflow free edge and a second outflow free edge opposite the at least one second inflow free edge. The second leaflet component being movable between an open position to allow fluid flow in a forward direction through the lumen and a closed position in cooperative engagement with the at least one first leaflet component that prevents fluid flow in a retrograde direction through the lumen. The first frame attachment edge of each first leaflet component being coupled to the inflow portion of the leaflet attachment region with the first inflow side facing the axis. The frame attachment edges of the second leaflet component being coupled to at least the outflow portion of the leaflet attachment region with the second inflow side facing the axis. Wherein a second overlap region of the second leaflet component adjacent the second inflow free edge overlaps a first overlap region of the first leaflet component adjacent the first outflow free edge such that they are in sealing engagement therewith when the leaflet is in the closed position defining a leaflet overlap region preventing fluid flow through the lumen in the retrograde direction. Wherein the first overlap region of each first leaflet component and the second overlap region are not in contact therewith wherein the first outflow free edge of the each of the first leaflet component and the second inflow free edge define a gap therebetween when the leaflet is not in the closed position, wherein fluid adjacent the second outflow side can pass through the gap during fluid flow in the forward direction.

A method for reducing incidents of thrombus or reducing thrombus formation associated with treating a human patient with a diagnosed condition or disease associated with valve insufficiency or valve failure of a native valve, the method comprising implanting a prosthetic valve at the location of the native valve. The prosthetic valve comprises a frame and a plurality of leaflets. The frame has an inflow end and an outflow end opposite the inflow end and defines a lumen therebetween defining an axis. The frame has at least one leaflet attachment region having an inflow portion and an outflow portion. Each leaflet being coupled to each of the at least one leaflet attachment regions. The at least one leaflet includes at least one first leaflet component and a second leaflet component. The at least one first leaflet component has a first inflow side and a first outflow side opposite the first inflow side. The at least one first leaflet component has a first frame attachment edge and a first outflow free edge, The second leaflet component has a second inflow side and a second outflow side opposite the second inflow side. The second leaflet component has a plurality of second frame attachment edges, at least one second inflow free edge and a second outflow free edge opposite the at least one second inflow free edge. The second leaflet component being movable between an open position to allow fluid flow in a forward direction through the lumen and a closed position in cooperative engagement with the at least one first leaflet component that prevents fluid flow in a retrograde direction through the lumen. The first frame attachment edge of each first leaflet component being coupled to the inflow portion of the leaflet attachment region with the first inflow side facing the axis. The frame attachment edges of the second leaflet component being coupled to at least the outflow portion of the leaflet attachment region with the second inflow side facing the axis. Wherein a second overlap region of the second leaflet component adjacent the second inflow free edge overlaps a first overlap region of the first leaflet component adjacent the first outflow free edge such that they are in sealing engagement therewith when the leaflet is in the closed position defining a leaflet overlap region preventing fluid flow through the lumen in the retrograde direction. Wherein the first overlap region of each first leaflet component and the second overlap region are not in contact therewith wherein the first outflow free edge of the each of the first leaflet component and the second inflow free edge define a gap therebetween when the leaflet is not in the closed position, wherein fluid adjacent the second outflow side can pass through the gap during fluid flow in the forward direction.

The prosthetic valve of the embodiments provided herein can be used as a prosthetic heart valve. In this capacity, the prosthetic valve is placed in an orifice collocated with a native heart valve or in place of an excised heart valve to regulate the flow of blood through the heart. It is believed that the leaflet moves to the first position, for example, as illustrated in <FIG>, during systole in which the heart forces blood through the artery or vein in a forward flow direction <NUM>. During diastole, the leaflet <NUM> moves to the closed position, illustrated in <FIG>, to substantially prevent fluid flow in the second, opposite direction referred to as retrograde flow. It is believed that a pressure change and reversal of flow direction occurs during the change from systole to diastole, and the leaflet <NUM> changes position in response to these changes.

The prosthetic valve of the embodiments provided herein can also be used as a prosthetic venous valve. In this capacity, the prosthetic valve is placed in a vein to regulate the flow of blood through the vein.

In accordance with an embodiment, a method of making a prosthetic valve comprises obtaining a leaflet frame, and a leaflet including a first leaflet component and a second leaflet component. Coupling the first leaflet component adjacent to an inlet portion of the leaflet frame. Coupling the second leaflet component adjacent to an outlet portion of the leaflet frame such that a second overlap region of a second inflow free edge of the second leaflet component overlaps a first overlap region of a first outflow free edge of the first leaflet component such that a portion of a second inflow side of the second leaflet component is in contact and in sealing engagement with a portion of a first outflow side of the first leaflet component when the leaflet is in a closed position defining a leaflet overlap region preventing fluid flow through the lumen in the retrograde direction. And wherein the first overlap region and the second overlap region are not in contact therewith wherein the first outflow free edge and the second inflow free edge define a gap therebetween when the leaflet is not in the closed position, wherein fluid adjacent the second outflow side can pass through the gap during fluid flow in the forward direction.

Claim 1:
A valve (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) having a leaflet (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) moveable between an open position that permits antegrade flow through the valve and a closed position that prevents regurgitant flow through the valve, the leaflet comprising an aperture or gap, or a separation (<NUM>, <NUM>, <NUM>) of portions of the leaflet to allow a flow or exchange of fluid between a front and back of the leaflet, when the leaflet is not in the closed position; and
wherein the aperture, gap or separation is operable to close to prevent flow of exchange of fluid between the back and the front of the leaflet, when the leaflet is in the closed position.