JP2016510645A - Improved leaflet and valve device - Google Patents

Abstract

The present invention provides a leaflet (140) for use in a prosthetic valve (100) that stabilizes the movement of the leaflet as it moves between an open position and a closed position. In certain embodiments, the prosthetic valve comprises a leaflet (140) that includes a reinforcing member (150) between the layers of film that comprise the leaflet.

Description

  The present invention relates generally to prosthetic valves, specifically valve leaflets such as prosthetic heart valves, and devices and systems having such valve leaflets.

  Bioprosthetic valves that try to imitate the function and performance of natural valves have been developed. Flexible leaflets are made from biological tissue such as bovine pericardium. In some prosthetic valve designs, biological tissue is sewn into a relatively rigid frame that supports the leaflet, providing dimensional stability upon implantation. Prosthetic valves provide superior hemodynamic and biomechanical performance in the short term, but are prone to failure, particularly calcification and leaflet tears, requiring reoperation and replacement.

  There has been an attempt to provide a more durable flexible leaflet prosthetic valve (referred to herein as a “synthetic leaflet valve” (SLV)) by using a synthetic material such as polyurethane as an alternative to biological tissue. Has been made. However, synthetic leaflet valves are not an effective valve replacement option because they fail prematurely, especially due to the suboptimal design and lack of durable synthetic materials.

  To connect the leaflets to the frame, numerous manufacturing techniques are used, such as injection molding or dip coating the polymer to the frame, only in the case of synthetic leaflets, where individual leaflets are sewn to the (biological and synthetic) frame. In many cases, the resulting leaflet is supported on a frame to define a flap having an attachment edge, where the leaflet is connected to the frame and the free edge, allowing the flap to move. The flap moves under the influence of fluid pressure. In operation, the leaflet opens when the upstream fluid pressure exceeds the downstream fluid pressure and closes when the downstream fluid pressure exceeds the upstream fluid pressure. The free edge of the leaflet joins under the influence of the downstream fluid pressure and closes the valve to prevent downstream blood from going back through the valve.

  The durability of a valve under load that repeatedly opens and closes the leaflet depends in part on the dynamic properties of the leaflet. In the case of a thin leaflet, the valve is repeatedly opened and closed, so that a crease is strongly formed in the central portion of the leaflet, and there are often holes in the leaflet where bending stress is repeatedly applied.

  One reason why the development of synthetic leaflet valves has not been successful to date is that the synthetic leaf is bent in a chaotic process. Each leaflet has a characteristic bending shape, and the shape is repeated in each cycle. However, the characteristic bending shape for each leaflet is different from the adjacent leaflet. The leaflet bending profile may be a continuous three-dimensional curve with a large radius. However, especially in the case of a very thin material, the bending in the radial direction is dense and the shape may be buckled out of the plane, and a strong tensile force is applied, which may cause a failure of the leaflet.

  Therefore, there is a need for a thin leaflet prosthetic valve that has comparable or improved hemodynamic performance while having a longer life compared to valves developed to date.

  In some embodiments, the present invention includes devices and systems for valve replacement or valvuloplasty, such as heart valve replacement. The present invention relates to a leaflet design or modification, and more particularly to a leaflet heart valve that not only improves the hemodynamics of a conventional prosthetic valve, but also reduces the premature occurrence of leaflet failure. In other words, the leaflet design presented herein improves the performance and life of valve leaflets that would otherwise show tight buckling in the radial direction.

  According to another embodiment, the leaflet comprises a guide member that improves lifespan and hemodynamic performance by stabilizing the movement of the leaflet. The guide member is operable to control the bending pattern or shape estimated by the leaflet as it moves between the open and closed positions. In addition, the guide member can be manipulated to minimize or eliminate dense radial bends, bucklings, wrinkles, and other undesirable folds in the center of the leaflet, so both hemodynamic performance and lifetime Improved.

  According to another embodiment, a leaflet for a prosthetic valve comprises a plurality of layers of films connected to each other and configured in the form of a leaflet. One or more guide members are connected between two of the multi-layer films, wherein the guide members are relatively stiffer than the multi-layer films.

  According to another embodiment, the prosthetic valve comprises a frame, at least one leaflet, and a guide member. Each leaflet comprises a plurality of layers of films that are connected to each other. Each leaflet defines a leaflet base, a leaflet edge opposite the leaflet base, and a central portion between the leaflet base and the leaflet edge. The leaflet is coupled to the frame along at least a portion of the leaflet base. The guide member is connected between two sheets of the multilayer film forming the leaflet. The guide member is located in the central portion and is separated from the frame. The guide member is relatively more rigid than the multi-layer film.

  According to another embodiment, the prosthetic valve comprises a frame, at least one leaflet, and a guide member. Each leaflet comprises a plurality of layers of films connected to each other. Each leaflet defines a leaflet base, a leaflet edge opposite the leaflet base, and a central portion between the leaflet base and the leaflet edge. Each leaflet is coupled to the frame along at least a portion of the leaflet base. Each leaflet is pivotable between an open position and a closed position. The central portion is more rigid than at least one of the leaflet edge and the leaflet base.

  According to another embodiment, a leaflet for a prosthetic valve includes a plurality of layers of films connected together and configured in the form of leaflets, and one or more guides connected between two of the layers of film. A member is provided. The leaflet defines a leaflet edge, a leaflet base opposite the leaflet edge, and a central portion between the leaflet edge and the leaflet base. The guide member is located in the central portion. The guide member is relatively more rigid than the multi-layer film. The one or more guide members are removed from the leaflet base such that when the leaflet is deployed within the prosthetic valve and the prosthetic valve is manipulated to bend the leaflet, the leaflet substantially pivots from the leaflet base. The length is aligned radially outward, but is spaced from the leaflet base.

  Each embodiment will be described with reference to the accompanying drawings. In the drawings, the same numbered elements indicate similar elements.

FIG. 1A is a top view of an embodiment of a valve in a closed configuration according to one embodiment.

FIG. 1B is an axial view of the embodiment of the valve of FIG. 1A in an open configuration according to one embodiment.

FIG. 2 is a perspective view of an embodiment of a valve in a closed configuration according to one embodiment.

FIG. 3 is a perspective view of an embodiment of a valve frame according to one embodiment.

FIG. 4A is a perspective view of an embodiment of a valve in a closed configuration with a leaflet including a guide member, according to one embodiment.

FIG. 4B is an axial view of the embodiment of the valve of FIG. 4A.

4C is an axial view of the embodiment of the valve of FIG. 4A.

FIG. 5 is an axial view of an embodiment of a valve in which the leaflet comprises a guide member, according to one embodiment.

FIG. 6 is an axial view of an embodiment of a valve in which the leaflet comprises a guide member, according to one embodiment.

FIG. 7 is an axial view of an embodiment of a valve in which a leaflet comprises one guide member and two guide members, according to one embodiment.

FIG. 8 is an axial view of an embodiment of a valve in which the leaflet comprises five guide members, according to one embodiment.

FIG. 9 is an axial view of an embodiment of a valve in which the leaflet comprises one central guide member and two side guide members, according to one embodiment.

FIG. 10 is an axial view of an embodiment of a valve in which the leaflet comprises a guide member, according to one embodiment.

FIG. 11 illustrates a side view of a leaflet frame coupled to a mandrel in the process of winding a film around a mandrel and including a guide member between at least two film layers to define the layer and the guide member, according to one embodiment. It is a perspective view.

FIG. 12 is a cross-sectional view of a guide member between layers of a film, according to one embodiment.

  Those of skill in the art will readily recognize that the various aspects of the present disclosure can be implemented by any number of methods and devices configured to perform the intended functions. In other words, other methods and apparatus may be incorporated herein to perform the intended function. It should also be noted that the accompanying drawings referred to in this specification are not all drawn to scale, but may be exaggerated to illustrate various aspects of the invention. In this respect, these drawings should not be construed as limiting.

  Although the embodiments described herein may be described in the context of various principles and views, the described embodiments are not bound by theory. For example, embodiments are described herein in the context of a prosthetic valve, more specifically in the context of a cardiac prosthetic valve. However, embodiments within the scope of this disclosure may be applied to any valve or mechanism of similar structure or function. Furthermore, embodiments within the scope of the present disclosure can be applied to uses other than the heart.

  As used herein in the context of a prosthetic valve, the term “leaflet” refers to a plastic component of a one-way valve, where the leaflet is in the open and closed positions under the influence of differential pressure. Can operate to move between. When in the open position, the leaflet allows blood flow through the valve. When in the closed position, the leaflet substantially blocks blood flow through the valve. In embodiments comprising multiple leaflets, each leaflet cooperates with at least one adjacent leaflet to prevent blood backflow. The differential pressure of blood is generated, for example, by contraction of the ventricle or the atrium, and such differential pressure is usually generated by fluid pressure accumulation on one side of the leaflet when the leaflet is closed. When the pressure on the inflow side of the valve is higher than the pressure on the outflow side of the valve, the leaflet opens and blood flows through the open leaflet. As blood flowing through the valve flows into a nearby chamber or blood vessel, the pressure on the inflow side is equal to the pressure on the outflow side. When the pressure on the outflow side of the valve becomes higher than the blood pressure on the inflow side of the valve, the leaflet returns to the closed position and generally prevents backflow of blood through the valve.

  As used herein, the term “membrane” refers to a sheet-like material comprising a single composition of a stretched fluoropolymer and a synthetic polymer having a structure defining fibers, such as, but not limited to, porous polyethylene. .

  As used herein, the term “composite material” refers to the combination of a membrane (eg, including but not limited to an expanded fluoropolymer) and an elastomer (eg, including but not limited to a fluoroelastomer). . The elastomer may be absorbed within the porous structure of the membrane, may be coated on one or both sides of the membrane, or may be a combination of coating and absorption on the membrane.

  As used herein, the term “laminate” refers to multiple layers of membranes, composites, or other materials (eg, elastomers), and combinations thereof.

  As used herein, the term “film” generally refers to one or more of a membrane, composite, or laminate.

  The term “leaflet window” is defined as the space defined by the leaflet frame from the root of the leaflet. The leaflets may extend from the leaflet frame element or may be spaced apart in the vicinity of the leaflet frame element.

  The terms “natural valve opening” and “tissue opening” refer to an anatomical structure in which the prosthetic valve may be placed. Examples of such anatomical structures include, but are not limited to, locations where the heart valve has been surgically removed or not removed. It will be understood that other anatomical structures that may be prosthetic valve placement include (but are not limited to) veins, arteries, ducts, and shunts. A valve opening or implantation site is understood to refer to any location within a synthetic or biological conduit where the valve may be placed.

  As used herein, the term “coupled” refers to connecting, connecting, attaching, adhering, affixing, or joining, whether directly or indirectly, and whether persistent or temporary. Means.

  Embodiments described herein include prosthetic valve devices, systems, and methods suitable for, but not limited to, heart valve replacement and the like. The valve can operate as a one-way valve, and when the leaflet is opened, flow to the valve opening defined by the valve is allowed, and when the leaflet is closed, the valve opening is blocked and backflow is prevented.

  This embodiment relates to an apparatus and system for valve replacement and augmentation, such as heart valve replacement. This embodiment relates to leaflet design or modification, and to leaflet heart valves that not only improve the hemodynamics of conventional prosthetic valves, but also reduce leaflet fatigue and failure. In other words, the leaflet embodiments shown herein improve leaflet bending, thereby improving lifespan and hemodynamics.

  Embodiments defined herein relate to a prosthetic heart valve leaflet that includes one or more guide members that allow control of leaflet movement, such as but not limited to control of leaflet bending features.

  According to the embodiments shown herein, the prosthetic valve comprises a plurality of polymer leaflets. Polymer leaflets include laminates composed of multiple layers of membranes, composite materials, or other materials such as elastomers, and combinations thereof. One or more guide members are connected to and contained within the laminate between the two layers of the multi-layer membrane or composite material. The guide member is operable to have a structural effect on the leaflet so as to control the leaflet bending characteristics. Since the guide member is completely contained within the layer of the laminate, the guide member remains permanently connected to the leaflet. Furthermore, since the guide member is completely contained within the layer of the laminate, the guide member is not exposed to the blood flow.

  Another embodiment relates to a leaflet support member and a prosthetic valve comprising at least one of the previously described leaflets, wherein the leaflet is connected to the support member along a leaflet base. The leaflet is between a first position and a second position such that in the first position the valve is a flow closure and in the second position the valve is a flow opening. Can move. The valve further comprises a guide member connected to the at least one leaflet as described herein. Similarly, in an embodiment of a valve 140 that includes a plurality of leaflets, at least one leaflet 140 includes a guide member 150, where at least one leaflet 140 does not necessarily include a guide member 150.

  In a further embodiment, the valve consists of a compression configuration and an expansion configuration. As such, the valve can be compressible or crushed under the application of restraining or compressive forces to obtain a compressed configuration. However, as soon as the force is removed, the expanded configuration of the valve, as before compression, is substantially maintained. For this purpose, the support member may comprise a shape memory material. The compressible valve is now known or may be implanted via endovascular techniques obtained below.

Valves FIGS. 1A and 1B are axial views of a valve 100 in a closed state and an open state, respectively, according to one embodiment. FIG. 2 is a perspective view of the valve 100 in a closed state. The valve 100 includes a frame 130 and a film 160 covering the frame 130 that form a leaflet 140 coupled with the frame 130 according to one embodiment. FIG. 3 is a perspective view of the frame 130 according to an embodiment.

The film 160 constituting the film leaflet 140 may comprise any biocompatible material having sufficient compatibility and flexibility, such as a biocompatible polymer. The film 162 may include a membrane that is combined with an elastomer to form a composite material. The film 160 according to one embodiment includes a composite material that includes an expanded fluoropolymer membrane having a plurality of spaces in a fibril matrix and an elastomeric material. It should be understood that multiple types of fluoropolymer membranes and multiple types of elastomeric materials can be combined to form a laminate without departing from the scope of the present disclosure. Without departing from the scope of the present disclosure, the elastomeric material may include a plurality of elastomers, a plurality of types of non-elastomers (eg, inorganic fillers, therapeutic agents, radiopaque markers, or the like). Should be understood.

  Film 160 generally refers to one or more of a membrane, a composite material, or a laminate, as defined above. The leaflet 140 includes a film 160. Details of the various types of film 160 are discussed below. In one embodiment, the film 160 may be formed from a generally tubular material to connect the frames 130 and form the leaflet 140. As discussed below, the laminate comprises multiple layers of membranes and / or composite materials, and also includes a guide member 150 connected and contained between at least two layers of membranes and / or composite materials.

  In one embodiment, the film 160 includes a biocompatible polymer combined with an elastomer, referred to as a “composite material”. The material according to one embodiment includes a composite material comprising an expanded fluoropolymer membrane that includes a plurality of spaces within a fibril matrix and an elastomeric material. It should be understood that multiple types of fluoropolymer membranes and multiple types of elastomeric materials can be combined to form a laminate without departing from the scope of the present disclosure. Also, the elastomeric material may include multiple elastomers without departing from the scope of the present disclosure, and multiple types of non-elastomeric components (eg, inorganic fillers, therapeutic agents, radiopaque markers, or the like) It should also be understood that may be included.

  According to one embodiment, the composite material includes an expanded fluoropolymer material made, for example, of a porous ePTFE membrane as outlined in Bacino US Pat. No. 7,306,729.

  The stretchable fluoropolymer used to form the stretched fluoropolymer material may comprise a PTFE homopolymer. In another embodiment, blends of expanded copolymers of PTFE, stretchable modified PTFE, and / or PTFE may be used. Non-limiting examples of suitable fluoropolymer materials include, for example, Branca U.S. Patent No. 5,708,044, Baillie U.S. Patent No. 6,541,589, Sabol et al. U.S. Patent No. 7,531,611, Ford U.S. Patent Application No. 11 / 906,877. And Xu et al., US patent application Ser. No. 12 / 410,050.

  The stretched fluoropolymer membrane may include any suitable microstructure to achieve the desired leaflet performance. According to one embodiment, the expanded fluoropolymer comprises a microstructure consisting of nodes interconnected with fibrils, as described, for example, in US Pat. No. 3,953,566 to Gore. From the nodes, fibrils extend radially in multiple directions, and the membrane has a generally homogeneous structure. Films with this microstructure can exhibit a matrix tensile strength ratio in two orthogonal directions typically less than 2 and possibly less than 1.5.

In another embodiment, the expanded fluoropolymer has a microstructure consisting essentially of fibrils, as outlined in Bacino US Pat. No. 7,306,729. An expanded fluoropolymer membrane having substantially only fibrils can have a surface area as great as greater than 20 m ² / g, or even greater than 25 m ² / g, and in some embodiments, the expanded fluoropolymer membrane is orthogonal Highly balanced strength with a product of matrix tensile strength in two directions of at least 1.5 × 10 ⁵ MPa ² and / or a ratio of orthogonal matrix tensile strengths in two directions of less than 4 and possibly less than 1.5 Can provide material.

To achieve the desired leaflet performance, the stretched fluoropolymer film can be adjusted to any suitable thickness and mass. For example, in a non-limiting example, the leaflet 140 includes an expanded fluoropolymer membrane that is about 0.1 μm thick. The expanded fluoropolymer membrane can also have a mass per unit area of about 1.15 g / m ² . The membrane according to an embodiment of the present invention may have a matrix tensile strength of about 411 MPa in the longitudinal direction and 315 MPa in the transverse direction.

Additional materials may be incorporated into the membrane pores, within the membrane material, or between the membrane layers to enhance the desired leaflet properties. To achieve the desired leaflet performance, the composite materials described herein may be adjusted to any suitable thickness and mass. The composite material according to the embodiment may include a fluoropolymer film, and may have a thickness of about 1.9 μm and a mass per unit area of about 4.1 g / m ² .

  Expanded fluoropolymers that are combined with elastomers to form composite materials provide the performance characteristics required for high cycle bendable implant applications (such as heart valve leaflets) in various ways for the various elements of the present disclosure. . For example, the addition of elastomers can eliminate or reduce the cure seen in ePTFE-only materials and improve the leaflet fatigue properties. In addition, it is possible to reduce the possibility of permanent strain deformation (wrinkles, folds, etc.) occurring in the material that may result in performance degradation. In one embodiment, the elastomer occupies substantially all of the pore volume or space within the porous structure of the expanded fluoropolymer membrane. In another embodiment, the elastomer is present in substantially all of the pores of at least one fluoropolymer layer. When the elastomer fills the pore volume or the elastomer is present in substantially all of the pores, the space in which foreign matter can be unnecessarily taken into the composite material is reduced. The foreign material is calcium that can be drawn into the membrane by contact with blood, for example. For example, when calcium is incorporated into a composite material used in heart valve leaflets, mechanical damage can occur during the opening and closing cycle, resulting in holes in the leaflets and poor hemodynamics.

  In one embodiment, the elastomer combined with ePTFE is a thermoplastic copolymer of tetrafluoroethylene (TFE) and perfluoromethyl vinyl ether (PMVE), as described, for example, in Chang et al. US Pat. No. 7,462,675. As described above, the elastomer is combined with the stretched fluoropolymer membrane to occupy substantially all of the gaps or pores in the stretched fluoropolymer membrane to form a composite material. Various methods can be used to fill the pores of the stretched fluoropolymer membrane with the elastomer as described above. In one embodiment, the method of filling the pores of the expanded fluoropolymer membrane includes dissolving the elastomer in a solvent and evaporating the solvent to leave a filler, the solvent comprising the expanded fluoropolymer membrane. It is a suitable solvent for preparing a solution having a viscosity and surface tension suitable for flowing into part or all of the pores.

  In one embodiment, the composite material comprises a total of three layers, two ePTFE outer layers and one fluoroelastomer inner layer disposed therebetween. Other fluoroelastomers may also be suitable and are described in Chang et al. US Patent Application Publication No. 2004/0024448.

  In another embodiment, the method of filling the pores of the expanded fluoropolymer membrane includes delivering the filler by dispersion to fill some or all of the pores of the expanded fluoropolymer membrane.

  In another embodiment, the method of filling the pores of the stretched fluoropolymer membrane comprises the step of sheeting the porous stretched fluoropolymer membrane under thermal and / or pressure conditions that allow the elastomer to flow into the pores of the stretched fluoropolymer membrane. Contacting with the elastomer.

  In another embodiment, the method of filling the pores of the expanded fluoropolymer membrane comprises first filling the pores with an elastomeric prepolymer and then at least partially curing the elastomer, thereby extending the expanded fluoropolymer membrane. A step of polymerizing the elastomer in the pores.

  After the elastomer reached the minimum weight percent, the performance of leaflets made of fluoropolymer material or ePTFE generally improved as the proportion of elastomer increased, resulting in a significant increase in cycle life. In one embodiment, the elastomer combined with ePTFE is a thermal of tetrafluoroethylene and perfluoromethyl vinyl ether, as described, for example, in Chang et al. US Pat. No. 7,462,675 and other documents known to those skilled in the art. It is a plastic copolymer. Examples of other biocompatible polymers that may be suitable for use in the leaflet 140 include urethanes, silicones (organopolysiloxanes), silicon-urethane copolymers, styrene / isobutylene copolymers, polyisobutylene, polyethylene- Co-poly (vinyl acetate), polyester copolymers, nylon copolymers, fluorinated hydrocarbon polymers and copolymers, and mixtures of each of these include, but are not limited to.

Frame FIG. 3 is a perspective view of the frame 130 of the embodiment of FIGS. 1A and 1B. The frame 130 is a generally tubular member that defines the valve opening 102 and provides structural load bearing support to the leaflet 140. Further, the frame 130 can be configured to securely engage the receiving tissue at the implantation site.

  The frame 130 can comprise any metal or polymer biocompatible material. For example, the frame 130 may be Nitinol, cobalt nickel alloy, stainless steel, and polypropylene, acetyl homopolymer, acetyl copolymer, expanded PTFE (polytetrafluoroethylene), other alloys or polymers, etc. (but not limited to) or book Any other biocompatible material having suitable physical and mechanical properties to function as described in the application can be included.

  For example, as shown in FIGS. 1A-B, 2 and 3, a stent having a frame 130 and an opening 122 is defined. The open framework of the stent can form any number of reproducible or non-reproducible features such as geometric and / or linear or sinusoidal serpentine continuums. The open framework can be formed into a tube or sheet of material by etching, cutting, laser cutting or stamping, and the sheet can then be formed into a substantially cylindrical structure. In another embodiment, the frame 130 can have a solid wall. Alternatively, an elongated material such as a wire, a bendable strip or a continuum thereof can be folded or knitted to form a substantially cylindrical structure. For example, the frame 130 can comprise a stent or stent-graft type structure known in the art.

  According to embodiments, the frame 130 can be configured to securely engage the implantation site. In another embodiment, the valve 100 further includes a sewing cuff coupled around a frame 130 that is operable to receive a suture to sew into a tissue opening known in the art. (Not shown). It should be appreciated that the valve 100 can be implanted using conventional surgical techniques for implanting a prosthetic valve.

  The frame 130 can include three U-shaped portions 132 that are interconnected. Each U-shaped portion 132 defines a base 134. U-shaped portion 132 intersects adjacent U-shaped portions to define post 131. The frame 130 shown in FIG. 3 includes three U-shaped portions 132 and three posts 131, and a leaflet 140 is connected to each of them as shown in FIG.

  The frame 130 can include any metal or polymer biocompatible material that can be elastically deformed, but is not limited thereto. The frame 130 may include a shape memory material such as nitinol or nickel titanium alloy. Other materials suitable for the frame 130 include other titanium alloys, stainless steel, cobalt nickel alloys, polypropylene, acetyl homopolymers, acetyl copolymers, other alloys or polymers, etc. (but not limited to) or described in this application. Including any other biocompatible material having suitable physical and mechanical properties to function as a frame 130 to perform.

Each of the U-shaped portions 132 of the leaflet frame 130 comprises a biocompatible material, such as a film 162 coupled to the frame outer surface 133a and the frame inner surface 133b of the frame 130; where the film 162 forms the leaflet 140. To do. Each leaflet 140 forms a leaflet free edge 142 that is not connected to the frame 130.

  According to one embodiment, the leaflet 140 can include a biocompatible material that is not biologically derived and that is well adapted and strong for a particular purpose, such as a biocompatible polymer. In one embodiment, the leaflet 140 includes a membrane combined with an elastomer to form a composite material.

  The shape of the leaflet 140 is formed in part by the shape of the frame 130 and the leaflet free edge 142. The shape of the leaflet 140 is also defined at least in part by the guide member 150, as described below. The shape of the leaflet 140 can also be defined by the structure and process used to manufacture the valve 100, such as, but not limited to, a molding and trimming process to give the leaflet 140 a set shape.

  Fluid flow can pass through the valve opening 102 when the leaflet 140 is in the open position as shown in FIG. The leaflet 140 generally bends around the base 134 of the U-shaped portion 132 when the leaflet 140 opens and closes. In one embodiment, when the valve 100 is closed, approximately half of each leaflet free edge 142 abuts the adjacent half of the adjacent leaflet 140 leaflet free edge 142 as shown in FIG. The three leaflets 140 of the embodiment of FIGS. 1A and 2 meet at a triple point 148. The valve opening 102 is closed when the leaflet 140 is in the closed position to stop fluid flow.

  The leaflet 140 can be configured to operate, for example, by a blood differential pressure caused by ventricular or atrial contraction, and this type of differential pressure is typically a fluid that increases on one side of the valve when the valve 100 is closed. As a result of pressure. When the pressure on the inflow side of the valve 100 exceeds the pressure on the outflow side of the valve 100, the leaflet 100 opens and blood flows through the valve. As blood flows through the valve and into adjacent chambers or blood vessels, the pressures are equal. When the pressure on the outflow side of the valve 100 exceeds the pressure on the inflow side of the valve 100, the leaflet 140 returns to the closed position, preventing blood from flowing back through the inflow side of the valve 100.

  The frame 130 can include any number of U-shapes that are suitable for a particular purpose, and thus can include leaflets. A frame 130 comprising one, two, three or more U-shaped portions 132 is understood.

  The film 160 can be coupled to the frame 130 in various ways suitable for a specific purpose. For example, without limitation, the frame 130 can be wrapped with an overlapping layer of film 160. The film 160 can be connected to the outer surface 133a of the frame 130 or the frame inner surface 133b. In another embodiment, the film 160 can be coupled to either the frame outer surface 133a or the frame inner surface 133b of the frame 130.

  The film 160 can be configured to prevent blood from flowing through or across the valve 100 in addition to passing through the valve opening 102 when the leaflet 140 is in the open position. Thus, the film 160 creates a barrier to blood flow in the interstitial space such as the opening 122 shown in FIG. 3 of the frame 130 that the film 160 covers.

  Film 160 can be secured or bonded at a single or multiple locations on frame outer surface 133a and inner surface 133b of frame 130 using, for example, one or more of taping, heat shrinking, bonding, and other processes known in the art. . In some embodiments, multiple membrane / composite layers or laminates can be used and bonded to frame 130 and frame 130 to form at least a portion of film 160.

Leaflet dynamics The leaflet 140 according to this embodiment, used in the context of a heart valve, flows between an open position and a closed position that allows blood to flow when opened and substantially blocks reversal of blood flow when closed. Configured to move. In embodiments comprising a plurality of leaflets 140, the leaflets 140 cooperate with at least one adjacent leaflet 140 to block blood backflow, and each leaflet is pivotally or pivotably attached to the frame 130. It is connected to a support member provided (but not limited to).

  As shown in FIG. 1B, when the leaflet 140 is in the open position, fluid flow is allowed to pass through the valve opening 102. As shown in FIG. 3, the leaflet 140 generally bends around the base 134 of the U-shaped portion 132 when the leaflet 140 is opened and closed. In one embodiment, when the valve 100 is closed, generally about half of each leaflet free edge 142 borders the adjacent half of the leaflet free edge 142 of the adjacent leaflet 140, as shown in FIG. . The three leaflets 140 of the embodiment of FIGS. 1A and 2 meet at a triple point 148. The valve opening 102 is blocked when the leaflet 140 is in the closed position and stops fluid flow.

  The leaflet 140 may be configured to operate, for example, with a blood differential pressure generated by a contraction of the heart's ventricle or atrium, and such differential pressure is typically a fluid pressure generated on one side of the valve 100 when closed. Caused by. When the pressure on the inflow side of the valve 100 is higher than the pressure on the outflow side of the valve 100, the leaflet 140 opens and blood flow passes through it. As blood flows through valve 100 into a nearby chamber or vessel, the pressure is equal. When the pressure on the outflow side of the valve 100 becomes higher than the inflow side blood pressure of the valve 100, the leaflet 140 returns to the closed position and generally prevents backflow of blood through the inflow side of the valve 100.

  For heart valve purposes, the leaflet thickness can range from about 10 μm to about 100 μm, while such thickness varies from the above range depending on the size, material, and desired function of the leaflet. May be. As discussed below, the improvements according to this embodiment may provide leaflet thicknesses outside the range of conventional thicknesses.

  FIG. 5 is an axial view representing the valve 101. Leaflet edge portion 113 includes a junction region 146 of leaflet 140. Central portion 147 includes a region between leaflet base 135 and leaflet edge 113. The joining area | region 146 is an area | region containing the confluence | merging point formed between the two leaflets 140 in a closed position. The leaflet 140 also includes the vertical axis X1. The height of the leaflet 140 is the length of the leaflet 140 along a parallel line to the longitudinal axis X1. The width of the leaflet 140 is the length of the leaflet 140 along the normal to the longitudinal axis X1, and it may vary between the leaflet base 135 and the leaflet free edge 142. The guide member defines the length of the guide member, and the leaflet defines the length of the leaflet extending from the leaflet base and the edge, the length of the guide member being shorter than the length of the leaflet.

Guide Member The leaflet embodiment shown herein includes one or more part guides operable to control the movement of the leaflet in a predetermined path.

  The guide member improves both lifespan, such as (but not limited to) service life, and hemodynamic performance of the valve.

  According to one embodiment, the leaflet further includes a guide member 150, as shown in FIGS. The guide member 150 stabilizes the movement of the leaflet 140 and / or affects the bending pattern or shape assumed by the leaflet 40 when moving between the open and closed positions shown in FIGS. 4B and 4C. It is a member inside. Similarly, the guide member 150 may be a load distribution member operable to distribute the load more evenly through the central portion 147 of the leaflet 40.

  According to the embodiment, the guide member 150 is a member disposed in the central portion 147 of the leaflet 140 that is spaced from the leaflet base 135 and spaced from the frame 130, and is along the longitudinal axis X <b> 1 that includes the guide member 150. It can be manipulated to resist deformations such as bends or close bends, and therefore the majority of the bends shift from the central portion 147 toward the leaflet edge portion 113 of the leaflet 140 and the leaflet base 135. By resisting such deformation, the central portion 147 pivots in a substantially more predictable manner substantially between the closed position and the open position, and vice versa. The guide member 150 according to this embodiment may facilitate pivoting of the central portion 147 relative to the leaflet base 135 in a substantially planar manner as opposed to a “rolling” open. By doing so, problems such as tight radial bending, buckling, undesirable creases or wrinkles, or the like, and other occurrences of service life and lifetime reduction are minimized or eliminated. . In various embodiments, the movement of the central portion 147 of the leaflet 140 between the first position and the second position substantially follows the guide member 150.

  With reference to FIG. 5, the guide member 150 is spaced from the leaflet base 135 and disposed in the central portion 147 of the leaflet 140 spaced from the frame 130. Guide member 150 is operable to stabilize, minimize or prevent leaflet deformation during movement of the leaflet between the open and closed positions, as shown in FIGS. 4B and 4C. . In one embodiment, most of the guide member 150 can be placed on or in the central portion 147 or coincides with the longitudinal axis X1. In one embodiment, the guide member 150 has a height that is less than the height of the leaflet and has a width through the same point that is shorter than the width of the leaflet through the point along the longitudinal axis X1. In other words, the guide member 150 in the embodiment does not extend to the full edge of the leaflet 140, such as but not limited to the leaflet base 135. In one embodiment, leaflet edge portion 113 and / or leaflet base 35 are not coupled to any portion of guide member 150. In one embodiment, the leaflet 140 includes a guide member 150 that substantially coincides with the longitudinal axis X1 and spans a range up to the connecting line of the shaft and at least half of the distance to the leaflet base 135 as a lower limit. . In various embodiments, the guide member 150 may have an orthogonal dimension that is longer or shorter than the longitudinal dimension.

  With the addition of the guide member 150, the size or number of S-shaped or S-shaped curves formed on the leaflet around the transitional longitudinal axis X1 may be reduced and most of such curves Are formed in a more controlled manner closer to the leaflet edge portion 113 and the leaflet base 135 of the leaflet 140.

  For example, some movement of the guide member 150 is substantially in a plane, substantially in an arc when the leaflet 140 moves from a first position to a second position, and in one embodiment It exists in an elliptical arc substantially. Overall, the movement of the guide member 150 follows a substantially planar swivel plane while moving between the first position and the second position.

  In one embodiment, the guide member 150 has any shape configured to resist leaflet deformation as described above, around the longitudinal axis, and according to one embodiment, on the majority of the central surface. Any configuration or any material may be included. For example, with reference to FIGS. 4B, 6-10, the guide member 150 may include at least one wire, or may include a region that is more rigid than a region without the guide member 150.

  Despite the presence of additional mass added to the leaflet 40, the leaflet 140, including the guide member 150, is more sensitive to changes in fluid pressure, which is the case if the bend does not include a guide member. It is believed that it is primarily because it occurs primarily at the leaflet edge portion 113 and the leaflet base 135 of the leaflet 140, rather than first due to undesirable bending and buckling at the center of the leaflet. Furthermore, as previously mentioned, the likelihood of leaflet failure is reduced by minimizing planar buckling.

  According to an embodiment, as shown in FIG. 12, the leaflet base 135 and the leaflet edge by at least one extra layer of film, fibers, and filaments located between two of the multi-layer film 160 including the leaflet 140. The rigidity of the central portion 147 is higher than that of the central portion 147.

  In one embodiment, the shape of the guide member 150 is a wire formed into an elliptical shape such as, but not limited to, a parallel-sided oval as shown in FIG. including. Alternative configurations are understood to include but are not limited to polygons, wavy shapes, S-shapes, straight wire, and figure 8 also known as a chain bead.

  FIG. 6 is an axial view of one embodiment of a valve 100b with a leaflet 140 that includes a second guide member 150b. Guide member 150b is spaced from frame 130 and is substantially V-shaped occupying a significant portion of leaflet 140.

  Similarly, leaflets need not be limited to one guide member per leaflet. FIG. 7 shows an embodiment of the second valve 100c with a leaflet 140 including a first guide member 150a with a third guide member 150c on each side of the first guide member 150a disposed aside. FIG. The first guide member 150a and the third guide member each have a substantially oval shape and are spaced from the frame and occupy a significant portion of the leaflet 140 relative to each other in the leaflet 140. Be placed.

  FIG. 8 is an axial view of one embodiment of a valve 100d with a leaflet 140 that includes a plurality of fourth guide members 150d. Each of the fourth guide members 150d is essentially a straight wire or a small diameter rod. The plurality of fourth guide members 150d are spaced from the frame and disposed relative to each other in the leaflet 140 so as to occupy a significant portion of the leaflet 140. The fourth guide member 150d extends from the adjacent leaflet base toward the leaflet free edge in a fan-like pattern.

  FIG. 9 is an axial view of one embodiment of a valve 100e that includes a leaflet 140 that includes a sixth guide member 150f disposed aside on a fifth guide member 150e on each side of the sixth guide member 150f. is there. The sixth guide member 150f is essentially a straight wire or a small-diameter rod with one end bent into a round shape. The fifth guide member 150e is essentially a wire or a small-diameter rod bent into a V or U shape with each end bent into a round shape. The round shape of the end can help to prevent the end from penetrating through the leaflet, causing the failure as compared to the sharp pointed end of the end that is not rounded. The plurality of sixth guide members 150f and the fifth guide member 150e are disposed with respect to each other in the leaflet 140 so as to occupy a substantial part of the leaflet 140. The sixth guide member 150f and the fifth guide member 150e are spaced from the frame 130 and extend from the adjacent leaflet base 135 of FIG. 5 toward the leaflet free edge 142 in a fan-like pattern.

  FIG. 10 is an axial view of one embodiment of a valve 100g with a leaflet 140 that includes a seventh guide member 150g. As shown in FIG. 5, the seventh guide member 150 g has a substantially triangular shape that is spaced from the frame 130 and occupies a part of the leaflet 140 having one side of the triangle adjacent to the leaflet base 135. .

  There can be any number of guide members and this embodiment stabilizes the movement of the leaflet over or around the longitudinal axis and the majority of the central portions or resists leaflet deformation. Any guide member is contemplated that includes any leaflet modification in any shape or configuration using any material in combination.

  According to embodiments, the one or more guide members 150 are substantially against a predetermined stress line corresponding to a stress line of the leaflet when the leaflet is deployed with the valve and the valve is operated to bend the leaflet. And has a length that is vertically aligned. The stress line of the leaflet 140 is substantially perpendicular to the line representing the fourth guide member 150d shown in FIG.

  The guide member 150 may include any material including a biocompatible material. For example, the guide member 150 may include a metallic material, a polymer material, or a ceramic material. The guide member 150 may be made of the same material as that of the leaflet 140 or may be made of a different material. Such materials may include shape memory materials such as nitinol. Other contemplated materials include PTFE such as ePTFE or other fluoropolymers, elastomers, polyurethane, stainless steel, or other biocompatible materials. According to this embodiment, the guide member 150 may be connected to the surface of the leaflet or embedded in the leaflet, such as between layers of leaflet material or components thereof.

  In one embodiment, the guide member 150 may include a plurality of materials, thereby providing resistance that may vary with respect to deformation along the length or width.

  According to embodiments, the guide member defines one of a polygonal shape, a rectangular elliptical shape, a wave shape, a continuous bead shape, and an S-shape.

Example 1
Referring again to FIGS. 4A-4C, the guide member 150 adds mass to the leaflet 140 in an embodiment. Therefore, the expected effect is a slower movement of the leaflet 140 compared to the leaflet 140 that does not include the guide member 150. Surprisingly, in an embodiment, a leaflet 140 that includes a guide member 150 has better hemodynamics than substantially the same leaflet that does not include a guide member. For example, 1.5-3.3 fold improvements in various performance parameters used to assess hemodynamics were observed. As pointed out above, such performance parameters include closing volume, back flow fraction (%), elapsed time to open and close, and crossing the open valve while the forward flow pressure is positive. A pressure drop can be mentioned. The following values suggest better performance. By adding a guide member 150, the closed volume and the backflow fraction can be reduced by at least a factor of two, and similarly, the change in pressure can be reduced by nearly a half. The following Table 1 is an example of actual improved hemodynamics observed by adding a guide member 150.

  Since the valve opening area at the open position was larger with the guide member 150 than without the guide member, the improved hemodynamics were confirmed visually. It was visually confirmed that the valve having the guide member 150 has a substantially more circular shape in its open position. More specifically, the shape formed along the outer periphery of the heart valve opening in the open position is substantially more circular due to the addition of the guide member 150 compared to the same valve without the guide member. It has also been observed that the leaflet 140 with the guide member 150 opens and closes in a manner that is less wrinkled and the center of the leaflet is more planar than the leaflet 140 without the guide member.

Example 2
The valve 100a of FIG. 4A with a polymer leaflet 140 is formed in the form of a composite material having an expanded fluoropolymer membrane and an elastomeric material, and is connected to a semi-rigid, unfoldable frame, and the following process Configured according to.

  A hard MP35N cobalt chrome tube with a diameter of 26.0 mm and a wall thickness of 0.6 mm was laser processed to produce a valve frame having the shape shown in FIG. Electropolishing the frame 130 removed 0.0127 mm of material from each surface, leaving a rounded edge. By performing the roughening operation on the frame 130, the adhesion of the leaflet to the frame 130 was improved without reducing the fatigue durability performance. The frame was cleaned by placing in an acetone ultrasonic bath for about 5 minutes. For cleaning, plasma treatment of the entire surface of the frame was performed as is generally known in the art. This treatment also serves to wet with a fluorinated ethylene propylene (FEP) adhesive.

  FEP powder (Daikin America, Orangeburg NY) was applied to the frame, but first the powder was agitated in a standard kitchen blender into an air-borne “cloud” and then the powder was spread over the entire surface of the frame The frame was suspended in the cloud until a uniform layer of was attached. Next, heat treatment was performed by placing the frame 130 in a forced air furnace set at 320 ° C. for about 3 minutes. By doing so, the powder melted and adhered to the entire frame 130 as a thin coating. The frame 130 was removed from the furnace and left to cool to room temperature.

  A stress relief and a sewing ring (not shown) were attached to the frame 130 as follows: a single layer of Kapton® (DuPont) polyimide film wrapped around a cylindrical mandrel with a diameter of 23 mm, overlapping seams Was held in place by an adhesive strip consisting of Kapton® tape over the entire length of the tape. A two-layer laminate having an ePTFE membrane bonded to a 25.4 μm thick fluoroelastomer layer as described below and shown in FIG. 11 along the axis of a mandrel 710 covered with Kapton®. It was wound once in the high strength direction so as not to substantially overlap at the position of the seam. The frame 130 was coaxially aligned on the wrapped mandrel 710. Another two-layer laminate was wound around the mandrel one more time with the seam facing 180 ° from the seam of the two-layer laminate wound once inside, sealing the entire frame 130. The end of the resulting four-layer laminate was cut at a position of about 135 mm from the base of the frame 130 sealed inside. The four-layer laminate having a length of 135 mm was manually wound axially toward the base of the frame to form a ring having an outer diameter of about 3 mm next to the base of the frame. After cutting the end of the four-layer laminate at a position about 20 mm from the top of the frame, the assembly is compressed, from two sacrificial layers consisting of ePTFE membrane that has absorbed polyimide, and from unsintered ePTFE membrane These four layers and about 100 turns of ePTFE fiber were spirally wound. The entire assembly was placed in a forced air furnace set at 280 ° C. for 5 minutes and heat treated, and then immediately removed from the furnace and rapidly cooled with water to return to room temperature. The sacrificial layer was removed, and the four-layer laminate located at the upper end of the frame was cut so that a length of 2 mm was extended beyond the periphery of the top of the frame. Next, when the mandrel and Kapton were removed from the inside of the frame, a frame assembly having a stress relaxation portion and a sewing ring in which the frame was laminated inside was obtained.

  A single female mold (not shown) was created that defined the shape of the three leaflets. Three identical male molds that match the shape and contour of the female mold, together with a mechanism that allows the male molds to pivot in the radial direction with respect to each other while maintaining both axial and rotational spacing Retained. One layer of ePTFE membrane that is substantially non-porous and has FEP on one side, wrapped with a single layer of ePTFE membrane that has not been sintered to act as a cushion layer, female mold and male mold The films are bonded to each other using a soldering iron, and are bonded to a mandrel using a soldering iron. The sacrificial layer ensures that when the male and female molds are compressed together, all surfaces that contact them have a cushion layer. Another function of the sacrificial layer is as a release layer, preventing the leaflet material from adhering to the mold. The male and female molds are initially joined together to form a single cylindrical structure that can be easily attached to the frame with the stress relief and suture ring through the process of winding the leaflet and winding the tape. To be.

  Next, a leaflet material was prepared. ePTFE membranes were prepared according to the general teachings described in US Pat. No. 7,306,729. The ePTFE membrane has a mass per unit area of 1.0 g / m 2, a matrix tensile strength of 447 MPa in the longitudinal direction, and 421 MPa in the transverse direction.

  The above membrane was imbibed with the copolymer fluoroelastomer. The copolymer consists essentially of about 65 to 70 weight percent perfluoromethyl vinyl ether and a supplementary about 35 to 30 weight percent tetrafluoroethylene. Additional fluoroelastomers may be suitable and are described in US Patent Application Publication No. 2004/0024448. The fluoroelastomer was dissolved in Novec HFE7500 (3M, St Paul, Minn.) At a concentration of 2.5%. The ePTFE membrane (supported by a polypropylene release film) was coated with this solution using a Mayer bar, and then dried in a convection oven set at 145 ° C. for 30 seconds. After two coating steps, the final ePTFE / fluoroelastomer or composite had a mass per unit area of 6.92 g / m 2, 14.4% by weight of fluoropolymer, and a thickness of 3.22 μm.

  Five layers of composite material are aligned around the combined mold by aligning the membrane so that the matrix tensile strength of 447 MPa is axially oriented and the elastomer-rich surface of the composite faces outward as viewed from the mold Wrapped around.

  A subassembly including a frame 130 with stress relief and stitching rings was aligned axially and pivotally to match the characteristics of the female mold beyond the three layers of inner wrap. An additional 10 layers of composite material, aligned with the membrane oriented so that the matrix tensile strength of 410.9 MPa is axially oriented and the elastomer-rich surface of the composite faces towards the mold Wound around.

  FIG. 11 is a simplified version of the above method showing a mandrel 710 with a frame 130 disposed thereon. The guide member of FIG. 4A included between two multi-layered films 160 as shown in FIG. 12, with the film 60 having a region 137 finally formed in the leaflet in the form of a composite. A mandrel 710 is wrapped around a frame 130 that forms a multi-layer film 160 having 150. The leaflet 140 includes a multi-layer film 160 connected together with an elastomeric material 164 therebetween. FIG. 12 is a cross section of a leaflet 140 showing a layer of film 160 between which elastomeric material 164 is bonded together and a guide member 150 between two multi-layer films 160.

  Next, the male mold was extracted from the lower part of the 15-layer composite material laminated tube. Each of the male molds expanded from one another around their base pivot. The male mold assembly was coaxially aligned with the female mold, making it easier for the male mold to press the overhanging 15 layer composite laminate tube against the female 3 leaflet mold surface. Compression was applied both in the radial and axial directions by applying a hose clamp to the male mold and simultaneously applying an axial load using the translation end of the lathe machine.

  Two sacrificial layers consisting of a supple ePTFE membrane that absorbs polyimide while applying compressive force to an assembly consisting of a male mold and a female mold, four layers of unsintered ePTFE membrane, and about 100 turns ePTFE fiber was spirally wound. The entire assembly was removed from the lathe and heat treated by placing it in a C-clamp fixture and maintaining axial compression for 30 minutes in a forced air oven set at 280 ° C. The assembly was removed from the furnace and immediately returned to room temperature by quenching with water. Removal of the sacrificial layer, male mold, and female mold left the well-adhered valve in a closed three-dimensional form.

  As shown in FIG. 4A, excess leaflet material was cut with scissors from the top of the frame column toward the triple point common to each leaflet to create three seams or interface areas. The leaflet was opened using an ePTFE mandrel that gradually thickened from 10 mm to 25 mm. A Branson ultrasonic compression welding apparatus with a valve assembly disposed in the fixture illustrated in FIGS. 28a and 28b, with a welding time of about 0.8 seconds and a holding time of about 3.0 seconds, with an air pressure of about 0.35 MPa. (# 8400, Branson ultrasonics, Danbury CT) was used to mold an annular suture ring at the base of the frame into a flange. Ultrasonic welding was performed twice to create a flange on the suture ring with a thickness of about 2 mm and an outer diameter of 33 mm.

  The final leaflet contained 14.4% by weight of fluoropolymer and had a thickness of 58 μm. Each leaflet was equipped with 15 layers of composite and the thickness / number of layers ratio was 3.87 μm.

  The resulting valve assembly is formed of a composite material having two or more fluoropolymer layers having a plurality of pores and an elastomer present in substantially all the pores of the two or more fluoropolymer layers. Equipped with a leaflet. Each leaflet circulates between a closed position shown in FIG. 4B, which prevents blood from flowing through the valve assembly, and an open position, shown in FIG. 4C, where blood can flow through the valve assembly. be able to. Thus, the leaflets of the valve assembly generally move repeatedly between a closed position and an open position to adjust the direction of blood flow in a human patient.

Typical anatomical pressure and flow across the valve were measured with a real-time pulse reproduction device to characterize the leaflet performance of each valve assembly. Flow performance was characterized in the following way:
1) The valve assembly was fitted into a silicone annular ring (support structure), and the valve assembly was evaluated with a real-time pulse reproduction device. The fitting was performed according to the instructions of the manufacturer of the pulse reproduction device (ViVitro Laboratories Inc., Victoria BC, Canada).
2) Next, the fitted valve assembly was placed in a real-time left heart blood flow pulsation reproduction system. This flow pulse reproduction system was equipped with the following parts supplied by VSI Vivitro Systems Inc., Victoria BC, Canada: Super Pump, Servo Power Amplifier, Part No. SPA3891; Super Pump Head, Part No. SPH 5891B, Cylinder 38.320 cm2; valve station / stationary; waveform generator, TriPack, part number TP 2001; sensor interface, part number VB 2004; sensor amplification part, part number AM 9991; square wave electromagnetic flow meter, Carolina Medical Electronics Inc. , East Bend, NC, USA. In general, flow pulse reproduction devices utilize a fixed displacement piston pump to generate a desired fluid flow through the valve under test.
3) The cardiac blood flow pulsation reproduction device was adjusted to generate the desired flow, average pressure, and simulated pulse rate. The valve under test was then operated repeatedly for about 5-20 minutes.
4) Pressure and flow data were measured and collected during the test period. The data includes ventricular pressure, aortic pressure, flow velocity, and pump piston position.
5) The parameters used to characterize the valve and to compare with the valve after the fatigue test are the pressure drop across the open valve while the forward flow pressure is positive, the effective area of the orifice , The backflow rate. The values recorded for this valve are shown in Table X below. All data contained in this table was recorded at 37 ° C. with a cardiac output of 5 liters / minute.

Example 3
As shown in FIG. 7, a first guide member 150a in which a third guide member 150c on each side of the first guide member 150a is disposed aside is completely included in each of the three leaflets 140. As described above, the second valve 100c was constructed as described above, except that it was incorporated into a laminated leaflet construct. The first guide member 150a and the third guide member 150c were constructed of 0.151 mm nitinol wires as elliptical members. The first guide member 150a and the third guide member 150c extend radially from the leaflet base 135 of the leaflet 140 as shown in FIGS. 5 and 7, but are arranged in a pattern spaced from the leaflet base 135 of the leaflet 140. And not attached to the frame 130. The first guide members 150a are 11.66 mm in length, and the third guide members 150c are each 10 mm in length. The first guide member 150a and the third guide member 150c were formed using pins and jigs, placed in an oven at 450 ° C. for 10 minutes, removed, and quenched with water. As described above, the valve was subjected to a real-time heart valve tester to measure performance characteristics (see Table 2).

Example 4
A third valve was similarly constructed as described above in Example 3 using three 0.151 mm guide members 150a, 150c (see FIG. 7) made of Nitinol. Although the center guide member 150a was comprised, it was the same as the center guide member 150a of Example 3, and the length was 11.43 mm. Each of the two side guide members or the third guide member 150c had a length of 8.26 mm. None of the three guide members 150 a and 150 c are directly attached to the frame 130 and are separated from the frame 130. These guide members 150a and 150c were formed as described in Example 3. As described above, the valve was subjected to a real-time heart valve tester to measure performance characteristics (see Table 2).

Example 5
Another valve identical to that of Example 1 was constructed and tested.

Example 6
In this embodiment, application of a non-metallic guide member is illustrated. An additional composite was formed from a composite material comprising a film of ePTFE imbibed with a fluoroelastomer as shown in leaflet 140 of FIG. A piece of film 160 in the form of a composite material about 10 cm wide is wrapped around a circular mandrel to form a tube. The composite material contained three layers: two outer layers of ePTFE and an inner layer of fluoroelastomer disposed therebetween. ePTFE membranes were prepared according to the general teaching described in US Pat. No. 7,306,729. The fluoroelastomer was as in Example 2.

  The ePTFE membrane had the following properties: thickness = about 15 μm; MTS in the strongest direction = about 400 MPa; MTS strength in the orthogonal direction = about 250 MPa; density = about 0.34 g / cm 3; IBP = about 660 KPa.

  The weight percent of fluoroelastomer relative to ePTFE was about 53%.

  The multilayer composite had the following properties: thickness = about 40 pm; density = about 1.2 g / cm3; force / width required for breaking in the strongest direction = about 0.953 kg / cm; strongest direction Tensile strength = about 23.5 MPa (3400 psi); required for break in the orthogonal direction / width = about 0.87 kg / cm; tensile strength in the orthogonal direction = about 21.4 MPa (3100 psi), and mass / area = about 14 g / m2.

  Ten layers of the composite were heated and compressed together to bond and form a single composite. A dart-shaped (not shown) side member was cut from a 10-layer sheet and subsequently bonded to a leaflet as in Examples 3 and 4. The test results are illustrated below in Table 3. With a slight increase in the degree of pressure drop, a decrease in reflux, leakage volume, and closed volume was observed.

Example 7
The purpose of this example is to show whether the guide member of one embodiment can be used with a valve provided via a catheter. Another valve, except that the utilized valve frame is of the kind that can be diametrically collapsed to a small diameter (6 mm) and then re-expanded to the original diameter of 26 mm by use of a balloon. This was constructed as in Example 3. In this case, the material used to form the leaflet had a weight / area of 0.3 gm / meter 2 and each layer was 30% ePTFE and 70% PMVE / PTFE copolymer. Using 50 layers, a leaflet with a final thickness of about 50 micrometers was formed. A guide member was formed and laminated to a leaflet as in Example 3.

  The results demonstrate that as shown in Table 4, the hemodynamic values are only slightly different (within the measurement error) after collapse / re-expansion before the collapse.

  The above disclosure is merely illustrative of the invention and is not intended to be construed as limiting the invention. While one or more embodiments of the invention have been described, those skilled in the art will readily appreciate that many modifications can be made without departing from the belief and scope of the invention. Accordingly, it should also be understood that all such modifications are intended to be included within the scope of the present invention.

Claims (68)

A leaflet for a prosthetic valve comprising: a plurality of layers of films connected to each other and configured in the form of leaflets; and one or more guide members connected between two of the layers of film;
Here, each guide member is a leaflet for artificial valves, which is relatively higher in rigidity than the multi-layered film. The leaflet of claim 1, wherein the one or more guide members have a length that is aligned substantially perpendicular to a predetermined stress line.
Here, the predetermined stress line corresponds to a stress line in the leaflet when the leaflet is deployed in the valve and the valve is operated to bend the leaflet.   The leaflet of claim 1, wherein the one or more guide members are spaced a predetermined distance from the frame. The leaflet defines a leaflet edge, a leaflet base opposite the leaflet edge, and a central portion between the leaflet edge and the leaflet base;
The leaflet according to claim 1, wherein the guide member is located in the central portion. The guide member defines a length of the guide member;
The leaflet defines a length of the leaflet extending from the leaflet base and leaflet edge;
The artificial valve according to claim 4, wherein a length of the guide member is shorter than a length of the leaflet.   The prosthetic valve according to claim 4, wherein the leaflet further comprises a longitudinal axis, and the guide member intersects the longitudinal axis.   The prosthetic valve of claim 4, wherein the leaflet further comprises a longitudinal axis, and the guide member is in a position substantially coincident with at least a portion of the longitudinal axis.   The artificial valve according to claim 1, wherein the guide member includes a shape memory material.   The artificial valve according to claim 1, wherein the guide member includes a metal material.   The artificial valve according to claim 8, wherein the guide member includes a shape memory material.   The artificial valve according to claim 8, wherein the guide member is formed of a wire.   The prosthetic valve of claim 8, wherein the leaflet comprises a polymeric material.   The prosthetic valve of claim 12, wherein the leaflet is formed from a composite material having a plurality of fluoropolymer layers.   The prosthetic valve according to claim 13, wherein the guide member is located between two fluoropolymer layers.   The prosthetic valve of claim 14, wherein the fluoropolymer layer comprises a plurality of pores.   The prosthetic valve of claim 15, wherein substantially all of the pores contain an elastomer.   The prosthetic valve of claim 16, wherein the elastomer comprises a fluoroelastomer.   The prosthetic valve of claim 16, wherein the elastomer comprises a TFE / PMVE copolymer.   The prosthetic valve of claim 17, wherein the fluoropolymer comprises PTFE.   The prosthetic valve according to claim 19, wherein the PTFE is ePTFE.   The prosthetic valve of claim 1, wherein the guide member defines one of a polygon, a square-side oval, a wavy shape, a continuous bead shape, and an S-shape. Frame; and
At least one leaflet comprising multiple layers of films coupled together; and
A prosthetic valve comprising: a guide member connected between two sheets of the multilayer film comprising the leaflet;
Where each leaflet defines a leaflet base, a leaflet edge opposite the leaflet base, and a central portion between the leaflet base and the leaflet edge;
The leaflet is coupled to the frame along a portion of the leaflet base;
The artificial valve, wherein the guide member is located in the central portion and spaced from the frame.   The artificial valve according to claim 22, wherein the guide member has a relatively higher rigidity than the multi-layer film. The guide member defines a length of the guide member;
The leaflet defines a length of the leaflet extending from the leaflet base and leaflet edge;
The prosthetic valve according to claim 23, wherein a length of the guide member is shorter than a length of the leaflet.   24. The prosthetic valve of claim 23, wherein the leaflet further comprises a longitudinal axis, and the guide member intersects the longitudinal axis.   24. The prosthetic valve of claim 23, wherein the leaflet further comprises a longitudinal axis, and the guide member is in a position substantially coincident with at least a portion of the longitudinal axis. The leaflet is operable to move between an open position and a closed position;
The guide member is relatively stronger than the multi-layer film,
23. The prosthetic valve of claim 22, wherein movement of the guide member between the open and closed positions by the leaflet follows a substantially planar swivel surface.   28. The prosthetic valve of claim 27, wherein movement of the central portion of the leaflet between the open and closed positions substantially follows the guide member.   23. The prosthetic valve of claim 22, wherein the guide member includes a shape memory material.   The artificial valve according to claim 22, wherein the guide member includes a metal material.   23. The prosthetic valve of claim 22, wherein the guide member includes a shape memory material.   The artificial valve according to claim 22, wherein the guide member is formed of a wire.   24. The prosthetic valve of claim 22, wherein the leaflet comprises a polymeric material.   34. The prosthetic valve of claim 33, wherein the leaflet is formed from a composite material having a plurality of fluoropolymer layers.   35. The prosthetic valve of claim 34, wherein the guide member is located between two fluoropolymer layers.   36. The prosthetic valve of claim 35, wherein the fluoropolymer layer comprises a plurality of pores.   37. The prosthetic valve of claim 36, wherein substantially all of the pores contain an elastomer.   38. The prosthetic valve of claim 37, wherein the elastomer comprises a fluoroelastomer.   38. The prosthetic valve of claim 37, wherein the elastomer comprises a TFE / PMVE copolymer.   40. The prosthetic valve of claim 38, wherein the fluoropolymer comprises PTFE.   41. The prosthetic valve of claim 40, wherein the PTFE is ePTFE.   38. The prosthetic valve of claim 37, wherein the guide member defines one of a polygon, a square oval, a wavy shape, a continuous bead, and an S-shape. Frame; and
A prosthetic valve comprising: at least one leaflet connected to the frame;
Here, each leaflet includes a plurality of layers of films connected to each other,
The leaflet defines a leaflet base, a leaflet edge opposite the leaflet base, and a central portion between the leaflet base and the leaflet edge;
The leaflet is coupled to a frame along a portion of the leaflet base;
A prosthetic valve, wherein each leaflet is pivotable between an open position and a closed position, and the central portion has a higher stiffness than at least one of the leaflet edge and the leaflet base.   44. The prosthetic valve of claim 43, wherein the average stiffness within the central portion varies.   44. The average stiffness within the central portion varies so that the leaflet changes between a substantially concave shape and a substantially convex shape as it pivots between the open position and the closed position. The artificial valve described in 1.   Due to at least one extra layer of film, fiber, and filament located between two of the multi-layer films comprising the leaflet, the rigidity of the central portion is relative to the leaflet base and the leaflet edge. 44. The prosthetic valve of claim 43, which is high. 44. The prosthetic valve of claim 43, further comprising a guide member connected between two of the multiple layers of film comprising the leaflet.
Here, the guide member is located in the central portion and is spaced apart from the frame, and the guide member has relatively high rigidity as compared to the multi-layer film.   48. The prosthetic valve of claim 47, wherein the guide member is selected from the group consisting of one extra layer of film, sheet, fiber, filament, and wire.   The guide member defines a length of the guide member, the leaflet defines a length of a leaflet extending from the leaflet base and a leaflet edge, and the length of the guide member is shorter than the length of the leaflet; The artificial valve according to claim 47.   48. The prosthetic valve of claim 47, wherein the leaflet further comprises a longitudinal axis, and the guide member intersects the longitudinal axis.   48. The prosthetic valve of claim 47, wherein the leaflet further comprises a longitudinal axis, and the guide member is in a position substantially coincident with at least a portion of the longitudinal axis.   48. The prosthetic valve of claim 47, wherein the guide member includes a shape memory material.   The artificial valve according to claim 47, wherein the guide member includes a metal material.   48. The prosthetic valve of claim 47, wherein the guide member includes a shape memory material.   48. The prosthetic valve of claim 47, wherein the guide member is formed from a wire.   48. The prosthetic valve of claim 47, wherein the leaflet comprises a polymeric material.   57. The prosthetic valve of claim 56, wherein the leaflet is formed from a composite material having a plurality of fluoropolymer layers.   58. The prosthetic valve of claim 57, wherein the guide member is located between two fluoropolymer layers.   59. The prosthetic valve of claim 58, wherein the fluoropolymer layer comprises a plurality of pores.   60. The prosthetic valve of claim 59, wherein substantially all of the pores contain an elastomer.   61. The prosthetic valve of claim 60, wherein the elastomer comprises a fluoroelastomer.   61. The prosthetic valve of claim 60, wherein the elastomer comprises a TFE / PMVE copolymer.   62. The prosthetic valve of claim 61, wherein the fluoropolymer comprises PTFE.   64. The prosthetic valve of claim 63, wherein the PTFE is ePTFE.   48. The prosthetic valve of claim 47, wherein the guide member defines one of a polygon, a square oval, a wavy shape, a continuous bead, and an S-shape. Multiple layers of films joined together and configured in the form of leaflets; and
A leaflet for a prosthetic valve comprising one or more guide members connected between two sheets of the multi-layer film,
Wherein the leaflet defines a leaflet edge, a leaflet base opposite the leaflet edge, and a central portion between the leaflet edge and the leaflet base;
Each guide member is located in the center,
The one or more guide members are leaflet such that when the leaflet is deployed within the prosthetic valve and the prosthetic valve is operated to bend the leaflet, the leaflet substantially pivots from the leaflet base. A leaflet for a prosthetic valve, which has a length aligned from the base toward the outside in the radial direction, but having a length spaced from the leaflet base.   68. The leaflet of claim 66, wherein the guide member is relatively stiffer than the multi-layer film.   68. The leaflet of claim 67, wherein the one or more guide members are spaced a predetermined distance from the frame.

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