Artificial heart valve and method of manufacturing the same

Abstract

The present invention relates to a prosthetic heart valve (100) for implantation into a patient's heart, comprising a stent frame (102), a plurality of cells arranged in a circumferentially aligned array, a valve element (120) attached to said prosthetic heart valve (100) and including at least two, preferably three, leaflets (121), and a skirt (130) attached to said stent frame (102), said skirt (130) including a skirt body (131) and at least two, preferably three, skirt flaps (132) integral with or attached to said skirt body (131). the skirt body (131) covers at least the proximal-most cell row (110) of the stent frame, each skirt flap forming a decoupling element (99) in a folded state, each skirt flap (132) covers one commissure cell (117) of the distal-most cell row (114) of the stent frame, and each leaflet (120) is attached to the prosthetic heart valve (100) within the commissure cell (117) of the distal-most cell row (114) via the decoupling element (99).

Description

[Technical field]

[0001] The present invention relates to a prosthetic heart valve for implantation in a body lumen, and in particular to a prosthetic heart valve for implantation in a body lumen via transluminal delivery. The prosthetic heart valve described herein is particularly suited for replacement of a native heart valve in a patient, as well as a method for manufacturing the prosthetic heart valve. [Background technology]

[0002] Valvular heart disease remains a significant cause of morbidity and mortality, and replacement of a patient's native diseased heart valve with a prosthetic heart valve has become a common surgical procedure for patients with valvular regurgitation or calcific stenosis of the valve leaflets.

[0003] Heart valve replacement is a procedure that is required when the body's natural heart valves are damaged, or are in a state of non-function or incapacity. In the heart, the valves open and close in response to the pressure difference on either side of the valve, maintaining one-way blood flow. The mammalian heart is made up of four chambers, two atria that store blood, and two ventricles that pump blood. The mammalian heart has four heart valves that allow blood to flow in only one direction, and each valve opens and closes in response to the pressure difference on either side of the valve.

[0004] Of the four main valves in the heart, the bicuspid mitral and tricuspid valves are located between the upper atrium and the lower ventricle, and are therefore called atrioventricular (AV) valves. The aortic and pulmonary valves are located in the arteries leaving the heart. The mitral and aortic valves are located in the left heart, and the tricuspid and pulmonary valves are located in the right heart.

[0005] Each valve has leaflets or cusps, each of which has three cusps except the mitral valve, which has two. For example, the aortic valve is made up of three leaflets, each leaflet / cusp called the right coronary cusp (RCC), left coronary cusp (LCC), and non-coronary cusp (NCC). Each cusp has two commissures, which are shared between adjacent cusps. The commissures are the spaces or areas where the two leaflets meet and fuse with the aortic wall. The commissures act as supports for the underlying structure of the valve cusp.

[0006] Ideally, the natural leaflets of a heart valve are separated when the valve is open and touch, or "coapt," when the valve is closed. Thus, heart valves can be affected by a variety of diseases that may necessitate heart valve replacement surgery. The valve may leak sideways, or regurgitate, or not close properly, in which case the aortic valve does not function and blood passively flows in the wrong direction back into the heart. The valve may also become partially closed, or stenotic, in which case it does not open completely and does not pump blood out of the heart. These two conditions often occur together.

[0007] Until recently, the majority of heart valve replacement procedures required a full median sternotomy and placement of the patient on a cardiopulmonary bypass. Traditional open-chest surgery can cause significant trauma and discomfort to the patient, require a long recovery period, and can lead to life-threatening complications. To address these concerns, efforts have been made over the past two decades to perform heart valve replacement using less invasive techniques, such as percutaneous entry via transluminal delivery. In such percutaneous heart valve replacement therapies, a catheter is used to deliver an artificial valve through a lumen in the patient's vasculature to the site of the disease.

[0008] Two types of prosthetic heart valve devices are generally used in cardiac surgery to replace damaged native heart valves: mechanical and bioprosthetic valve devices. Bioprosthetic valve devices typically use natural tissue obtained from a mammal, e.g., a pig or a cow, to form collapsible valve leaflets.

[0009] Although a great deal of effort has been invested in the development of prosthetic heart valves, existing prosthetic heart valves suffer from many shortcomings, including premature failure due to wear, manufacturing complexity, and suboptimal performance, which are attributable to both the valve elements and the frame of the prosthetic heart valve. For example, suboptimal leaflet designs can result in poor sealing of the flow passage when the prosthetic valve is in a closed state, undesirable leaflet overlap, and / or wrinkles in the folded leaflets. Additionally, frames that can act as stent elements when inserted into the heart often lack sufficient structure to support the commissures and / or the appropriate geometry to adequately secure the valve elements. A major shortcoming of most percutaneously placed prosthetic heart valves is the inflexibility of the leaflet attachment to the support structure, i.e., the stent frame. In light of this, surgically implanted prosthetic valves have been developed incorporating flexible regions in the area of ​​the commissure attachment points. This feature has been shown to improve the overall durability of the prosthetic valve by reducing leaflet stresses that cannot be dissipated by the flexible support structure. Incorporating such features is difficult in percutaneously placed heart valves, and especially in percutaneously placed balloon-expandable heart valves, as compared to surgically implanted prosthetic valves.

[0010] For a prosthetic heart valve to function perfectly, it is important that all components play their role. First, the valve must be properly attached to the frame / stent support; otherwise, the valve is prone to failure, and valve failure in the circulatory system will have serious consequences for the patient. On the other hand, the stent support must be fully expanded to ensure a secure fixation within the cardiac vessel.

[0011] Furthermore, loading of a prosthetic heart valve into a deployment system for minimally invasive surgery is by its nature very challenging as the prosthetic heart valve must be carefully loaded and at the same time compressed to fit snugly into the deployment system.

[0012] Thus, there is a need for improved prosthetic heart valve devices and methods for their manufacture. Summary of the Invention [Means for solving the problem]

[0013] According to the present invention, the above and other objects are achieved by: 1. A prosthetic heart valve for implantation in a patient's heart, comprising: a stent frame including a lumen, luminal and abluminal surfaces, and a plurality of cells arranged in circumferentially aligned rows; a valve element attached to the prosthetic heart valve and including at least two, preferably three, leaflets; a skirt attached to the stent frame; Including, the plurality of cells includes at least a proximal-most row of cells, at least one, and preferably two, three, four or five, intermediate rows of cells, and a distal-most row of cells; The skirt includes a skirt body and at least two, preferably three, skirt flaps integral with or attached to the skirt body; the skirt body covers at least the proximal-most row of cells, preferably at a luminal surface; each skirt flap covering a corresponding one of the commissure cells of the distal-most row of cells to form a decoupling element; the leaflets are attached to the prosthetic heart valve within the commissure cells of the distal-most cell row via respective decoupling elements; This can be solved by artificial heart valves.

[0014] By using the prosthetic heart valve of the present invention, more specifically by using a specific design, i.e. a decoupling element with a defined flexibility, provided in the prosthetic heart valve of the present invention, a commissure with a defined flexibility can be formed, i.e. the prosthetic heart valve can be flexibly attached via the commissures of the leaflets. Compared to known prosthetic heart valves, in which the commissures are usually fixed / sewn to a stent frame, the design of the present invention is superior due to the functionality of high flexibility of the whole valve. Furthermore, due to the controlled flexibility of the commissures, the tensile stress applied to the valve is reduced by being dissipated by the flexible decoupling element, which results in a longer life of the prosthesis / prosthetic heart valve.

[0015] As used herein, a "decoupling element" refers to an element having a degree of flexibility that decouples the fixation of the leaflets from the stent frame and stent struts and is not directly attached or fixed (e.g., sewn) to the stent frame or any part thereof, thereby decoupling the commissures and leaflets from mechanical loading from the stent frame.

[0016] According to one embodiment of the invention, the decoupling elements are formed by each skirt flap in a folded state, i.e. by folding the skirt flap so that one part of the skirt flap overlaps another part of itself.

[0017] Thus, a given or defined flexibility of the decoupling element can be achieved, for example, by using a particular material for the skirt flap.

[0018] Therefore, in one embodiment, the skirt flap has a predetermined flexibility, which is defined as a Young's modulus / tensile modulus of elasticity of 50-3000 MPa, preferably 100-500 MPa, as tested by a uniaxial tensile tester conforming to ISO 527-1. The mechanical loads experienced by the leaflets can be separated from the stent frame by this predetermined flexibility.

[0019] As generally understood herein, Young's modulus is understood to be the tensile or compressive modulus (e.g., negative stress), and is a mechanical property that indicates the tensile or compressive stiffness of a solid material when a force is applied longitudinally. Thus, Young's modulus indicates a defined flexibility. Young's modulus is a mechanical material property that is widely known in engineering design, especially in material science / material development. For example, one method for measuring Young's modulus / tensile modulus is to apply a tensile test standard in which Young's modulus is defined as the ratio of stress to strain under elastic load, and can be measured in accordance with ISO527-1 or ISO13934-1. In one embodiment, Young's modulus can be measured, for example, by the following method. The decoupling element is attached to a uniaxial tensile tester and pulled to the elastic limit, i.e., the yield strength. The modulus of elasticity, i.e., Young's modulus, is obtained from the coefficient of the obtained stress-strain ratio.

[0020] Said predetermined flexibility can be achieved, for example, by using a specific material for the skirt flaps, as defined below, which may be the same as or different from the material of the skirt body, and which may further comprise additional material to locally reinforce the decoupling element formed by the skirt flaps.

[0021] In one embodiment of the prosthetic heart valve of the present invention, the skirt flaps have a predetermined flexibility, and therefore the decoupling elements also have a defined flexibility. The flexibility of the decoupling elements can also be expressed in terms of Young's modulus, which is similar to or equal to the Young's modulus of the skirt flaps (when no reinforcement is provided between the skirt flaps) and / or the Young's modulus of the decoupling elements is preferably 50-3000 MPa, preferably 100-500 MPa, more preferably 150-300 MPa.

[0022] The decoupling or non-interlocking elements provide a mechanism for the leaflets to be flexibly attached to the prosthetic heart valve device, thereby improving the overall functionality of the valve. When the flexible valve element is closed, the mechanical loads on the valve element, which the valve element itself cannot dissipate to the rigid stent frame, can be dissipated to the stent frame via the decoupling elements. By reducing the stress levels on the leaflets, the useful life of the valve can be extended.

[0023] As used herein, and as generally understood, terms relating to the anatomical structure of the heart have the same meaning as generally understood in the art, and some of such terms are explained at the beginning of this specification.

[0024] The term "skirt" as used herein, as commonly understood in the art, refers to a sealing system consisting of a thin layer / film, usually made of biological or artificial material, attached to a stent frame with the aim of preventing paravalvular leakage. Attachment of the skirt to the stent frame is usually accomplished by sewing or chemically bonding the skirt to the stent frame.

[0025] As defined in accordance with the present invention, a "stent" or "stent frame" refers to a structural element that can be fixed in the annular heart valve tissue space. Typically, the stent frame is preferably made of a biocompatible metal frame, such as stainless steel or nitinol, and may be formed, for example, by laser cutting or braiding, or may be formed from braided wire filaments. Other stents suitable for use in the prosthetic heart valve of the present invention include rigid rings, helically wound tubes, or other tubes that fit snugly into the annular valve space and define an orifice through which blood can flow. Typically, the stent frame is preferably tubular or hollow cylindrical in shape.

[0026] In accordance with the present invention, a "valve" or "valve member / element," as generally understood, refers to a cardiac valve element that has a fluid-occluding surface that allows blood to flow in one direction while preventing blood flow in another direction, as described above. Valve members of various configurations can be utilized, including valve members with flexible leaflets, valve members with rigid leaflets, or valve members with a ball and cage configuration. The leaflets may be constructed of biological materials, synthetic materials, metallic materials, or other suitable means.

[0027] In this specification, the term "about" or "approximately" applies to any numerical value, whether or not the term is explicitly stated. This term generally refers to a numerical range that is considered equivalent to the stated numerical value by a person skilled in the art (i.e., a numerical range that achieves the same function or result as the numerical value). In many cases, this term may include numerical values ​​that are rounded to the nearest significant figure. Also, in this specification, the terms "substantially" and "substantially" or "essentially" mean that when various elements are compared to each other, the compared elements are equivalent or are sufficiently close in dimension that one skilled in the art can consider them to be equivalent. In this specification, the terms "substantially", "substantially" and "essentially" are not limited to a single dimension, but include a specific numerical range for the compared elements. This numerical range includes an acceptable variation that is considered reasonable by a person skilled in the art for the elements mentioned, such as a numerical value above the upper limit or a numerical value below the lower limit (e.g., as a numerical value more / less than, or larger / smaller than).

[0028] As used herein, the terms "integrally formed" or "integral" and "unitary construction" refer to a construction that does not include welds, fasteners, or other means for fastening separately formed pieces together.

[0029] Also, as used herein, "directly attached" with respect to a skirt body and a skirt flap means a direct connection between the skirt body and the skirt flap. For example, a skirt body made of a first material may be attached to a skirt flap made of a different material. Thus, the term "attached" includes means for fastening separately formed members of the same or different materials together.

[0030] In the context of the present invention, the terms "proximal" and "distal" are used interchangeably with "inflow" and "outflow", respectively, e.g., the "proximal" cells of the stent frame are the cells at the (blood) inflow end and the distal-most cells are the cells at the (blood) outflow end of the stent frame. In other words, the proximal-most row of cells is the row of cells at the most proximal end of the stent frame and the distal-most row of cells is the row of cells at the most distal end of the stent frame. Similarly, the stent frame has a proximal end (inflow end) and a distal end (outflow end). Thus, for example, the prosthetic heart valve shown in FIG. 1 is shown in an orientation related to implantation of this prosthetic heart valve, and the proximal-most row of cells of the stent frame are the cells located at the inflow end of the stent frame and the distal-most row of cells of the stent frame are the cells located at the outflow end of the stent frame.

[0031] As used herein, the term "cell" refers to a closed section of the stent frame that (when not covered by prosthetic material attached to the stent frame) forms a "hole" in the stent frame. Each cell can be formed into a variety of shapes by surrounding it with stent material or stent struts. A cell row is a series of cells immediately adjacent to one another circumferentially around the tubular stent frame, with adjacent cells sharing an end or strut with the adjacent cell to the left or right.

[0032] For purposes of this invention, a "skirt flap" is a portion of the skirt that extends from the skirt body and has only one end attached to and integral with the skirt body, the other end extending as a free end.

[0033] According to a preferred embodiment of the present invention, the decoupling elements function to attach the leaflets to the prosthetic heart valve in the commissure cells of the distal-most row of cells covered by the skirt flap, whereby the skirt flap covering the cells functions as the decoupling elements.

[0034] In this embodiment, the skirt flap has a defined flexibility and the leaflets attached to this skirt flap can also have that flexibility, so that the skirt flap covering the commissure cells of the distal-most cell row can be advantageously used as an attachment area.

[0035] Also, with the present invention, the leaflets do not contact the stent frame at the commissures.

[0036] According to one embodiment of the prosthetic heart valve of the present invention, each skirt flap includes an opening disposed within a commissure cell covered by the respective skirt flap.

[0037] This embodiment has the advantage that the leaflets can be attached to the skirt flap through this opening and still maintain flexibility of and attachment to the skirt flap.

[0038] In one embodiment of the prosthetic heart valve of the present invention, the skirt body is attached to the luminal surface of the stent frame.

[0039] In one embodiment of the prosthetic heart valve of the present invention, the skirt body is preferably attached to the luminal surface of the stent frame, and each skirt flap includes a first portion and a second portion, the first portion being preferably attached to the luminal surface of the stent frame and having an opening disposed in at least one commissure cell, and the second portion being preferably designed to cover at least a portion of the opening by being attached to the abluminal surface of the stent frame by folding back at the distal-most end of the commissure cell from the luminal surface side of the stent frame to the abluminal surface side of the stent frame.

[0040] In this embodiment, the skirt flap is also used as an attachment means for the leaflets. Each leaflet can be guided from the luminal surface of the stent frame through the opening of the first portion of the skirt flap covering the commissure cell, and the second portion of the skirt flap can be folded back at the most distal end of the commissure cell to cover the opening and at least a part of the commissure cell. In this way, the second portion of the skirt flap is folded back from the luminal surface side to the abluminal surface side of the stent frame. Thus, the leaflets can be more firmly attached while maintaining their flexibility.

[0041] Thus, in one embodiment, a first portion of the skirt flap is attached to the luminal surface of the stent frame and a second portion of the skirt flap is attached to the abluminal surface of the stent frame.

[0042] In another embodiment, each skirt flap comprises a first portion and a second portion, the first portion being attached to the luminal surface, the first portion including an opening disposed in at least one commissure cell, and preferably the second portion of each skirt flap being attached to the abluminal side of the stent frame by folding back from the luminal surface of the stent frame around a lateral strut of the commissure cell and designed to cover at least a portion of the opening.

[0043] In another embodiment, the skirt body is attached to the luminal surface of the stent frame, and each skirt flap includes a first portion and a second portion, the first portion being attached to the abluminal surface and the second portion being designed to be folded from the abluminal surface of the stent frame around a lateral strut of the commissure cell to the luminal surface of the stent frame such that the second portion is attached to the luminal side of the stent frame and an opening is formed in the luminal surface.

[0044] Thus, in one embodiment of the prosthetic heart valve of the present invention, each leaflet includes a leaflet body and a leaflet flap, the leaflet body being disposed within the lumen of the stent frame, and the leaflet flap being guided from the luminal surface to the abluminal surface of the stent frame through openings disposed in the commissure cells covered by the skirt flaps and fixed in position via decoupling elements.

[0045] In one embodiment of the prosthetic heart valve of the present invention, the distal-most cell row includes at least two, and preferably three, commissure cells separated from one another by separate cells, each commissure cell being longer than the separate cells and thus protruding in the distal direction D.

[0046] This embodiment, and more specifically the particular form of the commissure cells, allows for adaptation to the anatomical structure of the heart: since only two or three long commissure cells are provided, the vascular site in which the prosthetic heart valve is placed is not uniformly covered circumferentially by the most distal end of the prosthetic heart valve, and the short, separate cells provide spaces between the long commissure cells, allowing branch arteries, such as the coronary arteries, to remain open.

[0047] Thus, in one preferred embodiment, the distal-most cell row includes three commissure cells each separated from the others by three separation cells, the commissure cells being longer than the separation cells.

[0048] In the present invention, the term "long" means that the commissure cells protrude distally by a certain length x compared to the shorter separated cells, which may be from about 2 mm to about 8 mm, and is preferably 5 mm or less.

[0049] Also, for purposes of the present invention, the term "commissure cells" refers to cells that form the commissures of a valve element because they function as areas of attachment for the leaflets of the valve element, and "isolation cells" therefore refers to the distal-most row of cells that separate the commissure cells from one another.

[0050] In one embodiment of the invention, the commissure cells may be substantially diamond shaped and the separation cells may be substantially triangular shaped.

[0051] The special design of the commissure cells and separation cells provides a stent frame design that can securely anchor the distal portion of the prosthetic heart valve to the native valve area while ensuring that the replacement valve element is fully functional without the prosthetic heart valve occluding the branch arteries.

[0052] In one embodiment of the prosthetic heart valve of the present invention, the proximal-most row of cells includes substantially heart-shaped cells.

[0053] The design of the proximal-most cell row shape allows the entire prosthetic heart valve to be well adjusted to the heart wall, achieving a good seal, and the special heart-shaped cells have the advantage of reducing radial forces, preventing problems caused by irritation.

[0054] In one embodiment of the prosthetic heart valve of the present invention, the stent frame includes at least one intermediate row immediately adjacent the distal-most row, which intermediate row preferably includes substantially triangular cells.

[0055] The provision of triangular cells allows for an asymmetric cell design, which may also allow branch arteries, such as coronary arteries, to remain open.

[0056] According to one preferred embodiment, the number of cells in the intermediate row immediately adjacent to the distal-most row is between 6 and 16, i.e., 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 or 16 cells, preferably 12 cells.

[0057] In one embodiment of the prosthetic heart valve of the present invention, the stent frame includes a first intermediate row immediately adjacent the proximal-most row, which first intermediate row preferably includes substantially hexagonal cells.

[0058] In one embodiment of the prosthetic heart valve of the present invention, the stent frame includes a second intermediate row immediately adjacent to the first intermediate row, the second intermediate row preferably including substantially hexagonal cells.

[0059] The stent frame preferably includes a second intermediate row immediately adjacent the first intermediate row, the second intermediate row preferably including substantially hexagonal cells.

[0060] In one embodiment of the present invention, the first intermediate row and the second intermediate row each include 6 to 16 cells, preferably 10 to 12 cells, and more preferably 12 cells each.

[0061] In one embodiment of the prosthetic heart valve of the present invention, the first intermediate row and the second intermediate row include symmetric cells.

[0062] One embodiment of the prosthetic heart valve of the present invention includes a stent frame having five cell rows, i.e., a distal-most cell row, three intermediate cell rows, and a proximal-most cell row, the distal-most and proximal-most cell rows containing cells of the shape defined above, and the three intermediate cell rows, an intermediate row immediately adjacent (proximally) to the distal-most row, a first intermediate row immediately adjacent (distally) to the proximal-most row, and a second intermediate row adjacent (distally) to the first intermediate row, also containing cells of the shape defined above.

[0063] In one embodiment of the prosthetic heart valve of the present invention, the skirt, i.e., the skirt flap and / or the skirt body, comprises a fabric, film or tissue material having a predetermined flexibility, preferably a uniform predetermined flexibility, and preferably comprises a material selected from polyester, polyurethane, and polytetrafluoroethylene (PTFE).

[0064] By providing a material with a uniform, defined flexibility, the decoupling element described above can also ensure that defined flexibility, thereby allowing the leaflets to be securely attached while retaining a given flexibility.

[0065] The valve element, and in particular the leaflets of the valve element, are preferably constructed from mammalian pericardium.

[0066] In one embodiment of the prosthetic heart valve of the present invention, the stent frame is a balloon-expandable stent frame or a self-expanding stent frame.

[0067] A self-expanding stent frame can be folded or compressed to fit into a narrow tube and has sufficient elasticity to self-expand when the constraint of an external sheath or the like is removed. In contrast, a balloon-expandable stent frame is made of a material with little elasticity and must plastically expand from the inside to assume a shape when expanded from a reduced diameter state. The term "balloon-expandable stent frame" is intended to include a plastically expandable stent frame, whether or not it is actually expanded using a balloon (e.g., the stent frame can also be expanded with a device having mechanical fingers). The stent frame material plastically deforms after application of a deforming force, such as by an inflatable balloon or expandable mechanical fingers. Thus, the term "balloon-expandable stent" is understood to refer to the material or type of stent frame, rather than a specific expansion means.

[0068] The present invention further provides a method of producing a prosthetic heart valve, comprising the steps of: providing a stent frame including a plurality of cells arranged in circumferentially aligned rows, the plurality of cells including at least a proximal-most row of cells, a middle row of cells, and a distal-most row of cells, a lumen, and a luminal surface and an abluminal surface; a step of attaching, preferably by sewing, a skirt comprising a skirt body and at least two, preferably three, skirt flaps integral with the skirt body to the stent frame, such that the skirt body covers at least the proximal-most cell row on the luminal surface of the stent frame, a first portion of each skirt flap including an opening covers cells of the distal-most cell row on the luminal surface of the stent frame, and a second portion of each skirt flap is positioned to extend beyond the distal-most end of the cell covered by the first portion; attaching at least two, preferably three, leaflets, including a leaflet body and a leaflet flap, to the stent frame, such that the leaflet body is disposed within the lumen of the stent frame, and the leaflet flap is guided from the luminal surface to the abluminal surface of the stent frame through an opening in a first portion of the skirt flap; folding back a second portion of each skirt flap at a distal-most end of the cell covered by the first portion of the corresponding skirt flap to cover the leaflet flap and at least a portion of the opening with the second portion; Attaching a second portion of the skirt flap to the stent frame and securing the leaflets to the stent frame via a decoupling element. A method comprising: Regarding.

[0069] Using the methods provided herein, the valve element can be securely and reliably mounted within the stent frame while still allowing the valve element to be flexibly mounted, optimizing the distribution of stresses so that the valve element operates and functions as naturally as possible.

[0070] In the context of the prosthetic heart valve and its manufacturing method of the present invention, the expression "attaching the valve leaflets to the stent frame via the decoupling elements" means that the valve leaflets are not directly attached to the stent frame, but rather are directly attached to the decoupling elements (and thereby indirectly attached to the stent frame), such that the decoupling elements are integral with and connected to the stent frame.

[0071] In one embodiment of the method of the invention, each leaflet comprises two flaps that are guided through the opening in a folded state, unfolded after passing through the opening, and then covered by a second portion of the skirt flap.

[0072] Moreover, in one embodiment of the method of the present invention, the prosthetic heart valve disclosed above is produced.

[0073] The prosthetic heart valve / prosthetic heart device of the present invention is suitable for and is used to replace mammalian heart valves, preferably human, preferably adult, heart valves, i.e. aortic, pulmonary, mitral and tricuspid valves, with aortic valve replacement being preferred.

[0074] Accordingly, the present invention further provides a method for treating a damaged native valve of a mammalian heart, preferably a human heart, to replace the function of the damaged native valve, comprising the steps of: The bioprosthetic valve is preferably an aortic valve; The method of treatment comprises: advancing a prosthetic heart valve as disclosed above through a patient's vascular system and along a vessel wall to a treatment site; (i) expanding an expansion member within the stent frame to expand the stent frame into contact with the vessel wall; or (ii) withdrawing the sheath housing the compressed prosthetic heart valve, thereby allowing the stent frame to self-expand and contact the vessel wall; The present invention relates to a method comprising the steps of:

[0075] The features described hereinbefore and hereinafter may be included in the scope of the present invention not only in the combinations specified, but also in other different combinations or alone. It should therefore be recognized that the present disclosure also relates to other embodiments having any other possible combinations of features recited in the dependent claims. For example, for purposes of claim disclosure, if a multiple dependent claim format is permitted in a jurisdiction, each subsequent dependent claim should be construed as being alternatively written in a multiple dependent claim format dependent on all preceding claims with all antecedents referenced in each dependent claim (e.g., each claim directly dependent on claim 1 should be construed alternatively as being dependent on all preceding claims). In jurisdictions where the multiple dependent claim format is limited, each subsequent dependent claim should be construed as being alternatively written in a single dependent claim format dependent on a preceding claim with an antecedent other than the specific claim recited in each dependent claim.

[0076] Preferred embodiments are illustrated in the drawings and are explained in more detail below. [Brief description of the drawings]

[0077] The figures are as follows:

[0078] [Figure 1] 1 shows a schematic diagram of a stent pattern with a flattened stent frame in a tubular form in one embodiment of the prosthetic heart valve of the present invention. (A) shows the first view without showing the external shape of the prosthetic heart valve. (B) shows a schematic view of the external shape of the attached prosthetic heart valve. (C) shows the tubular stent frame.

[0079] [Diagram 2] FIG. 2 shows a schematic diagram of a skirt element used in one embodiment of the prosthetic heart valve of the present invention, shown flat and unattached to a stent frame.

[0080] [Diagram 3]1A-1B show schematic diagrams of leaflets of a valve element of one embodiment of a prosthetic heart valve of the present invention, illustrating two different shapes of a single leaflet (A) and (B).

[0081] [Figure 4] 1 shows a partially enlarged view of a stent frame, illustrating a part of a method for manufacturing a prosthetic heart valve of the present invention. (A) A skirt is attached to a stent frame of one embodiment of a prosthetic heart valve of the present invention, such that the skirt body covers the most proximal and middle rows of the stent frame and a first portion of the skirt flap covers the cells of the most distal cell row of the stent frame, but before the second portion of the skirt flap is folded back and before the leaflets are guided through the opening. (B) A portion of the leaflets is guided through the opening, but before the second portion of the skirt flap is folded back. (C) The second portion of the skirt flap is folded back at the end of the cell covered by the first portion.

[0082] [Diagram 5] 1A-1C are schematic diagrams of a cross section of a portion of a stent frame of an embodiment of a prosthetic heart valve of the present invention, showing a portion of a leaflet flap being guided through an opening in a first portion of a skirt flap covering the distal-most row of cells of the stent frame; (A) shows an embodiment in which a second portion of the skirt flap is folded over the distal-most end of the commissure cell, but does not surround the struts of the commissure cell of the stent frame; (B) shows an embodiment in which a second portion of the skirt flap is folded over the distal-most end of the commissure cell, the skirt flap surrounds the struts of the commissure cell of the stent frame; and (C) shows an embodiment in which a second portion of the skirt flap is folded over the distal-most end of the commissure cell, the skirt flap surrounds the struts of the stent frame commissure cell, and the second portion of the skirt flap is split and overlaps each other.

[0083] [Figure 6]1 shows a schematic diagram of the mechanism of the decoupling element, (A) is a front view, and (B) is a cross-sectional view cut at the stent frame.

[0084] [Figure 7] FIG. 1 shows a perspective view of one embodiment of an assembled prosthetic heart valve of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0085] The accompanying drawings, which are incorporated in and form a part of this specification, serve to explain the principles of the invention and to enable one of ordinary skill in the art to make and use the invention, although the drawings are not drawn to scale.

[0086] Specific embodiments of the present invention are now described with reference to the figures, in which like reference numbers indicate identical or functionally similar elements. The following detailed description is merely exemplary in nature and is not intended to limit the invention itself or its uses. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.

[0087] 1A and 1B show schematic diagrams of a stent pattern of a stent frame 102 in a closed tubular configuration in an embodiment of a prosthetic heart valve 100 of the present invention, laid flat. As shown in Fig. 1A, the stent frame 102 includes a plurality of circumferentially arranged rows 110, 111a, 111b, 112, and 114. More specifically, the stent frame 102 includes a proximal-most row 110, a distal-most row 114, an intermediate row 112 immediately adjacent to the distal-most row 114 (in the proximal direction P), a first intermediate row 111a immediately adjacent to the proximal-most row 110 (in the distal direction D), and a second intermediate row 111b immediately adjacent to the first intermediate row 111a.

[0088] 1A, 1B, and 1C, the proximal-most row 110 includes a plurality of substantially heart-shaped cells. In the embodiment shown in this figure, each cell of the proximal-most row 110, being heart-shaped, is larger and has a larger opening than each cell of the first intermediate row 111a and the second intermediate row 111b.

[0089] The heart shape is provided as an example, and other shapes that serve the same purpose, i.e., that provide good attachment to the heart wall and are sealable, may be used.

[0090] Each cell of the first intermediate column 111a and the second intermediate column 111b is substantially hexagonal and, in the embodiment shown in Fig. 1, is smaller than each cell of the most proximate column 110. As a result, the first intermediate column 111a and the second intermediate column 111b contain a larger number of cells. In the embodiment shown in Fig. 1, and particularly with reference to Fig. 1C, the most proximate column contains 6 cells, and the first intermediate column 111a and the second intermediate column 111b contain 12 cells each. However, these numbers of cells are provided as an example, and other numbers or ranges of numbers can be used to achieve the same purpose.

[0091] In the embodiment shown in FIG. 1, the distal-most cell row 114 includes a plurality of cells, including three large cells, also designated as commissure cells 117, each separated from the other by a separate cell 118. In the embodiment shown in FIG. 1, the three commissure cells 117 are separated from the other by three separate cells 118. The commissure cells 117 are larger and longer than the separate cells 118, and therefore protrude in the distal direction D compared to the shorter separate cells 118. The length L of the commissure cells is longer than the shorter separate cells, in other words, protrudes from the shorter separate cells by about 2 mm to about 2 cm, preferably 2 mm to 8 mm.

[0092] These three commissure cells 117 are the commissure-attached (via a skirt, described below) cells 117. The two middle rows 111b and 111a apply radial force to secure the prosthetic heart valve at the implantation site.

[0093] In the embodiment shown in Figure 1, the proximal-most cell row 110 includes six heart-shaped cells, which reduces radial forces and increases flexibility, thereby better conforming to the annulus of the native heart valve being replaced. The different shapes of the cells in each row result in different inclinations of the struts interconnecting each cell. The different inclinations reduce radial forces and can prevent problems caused by irritation.

[0094] 1B also shows a schematic of the attachment points of the commissures (attached via skirt 130; not shown in FIG. 1; described below) and the coaptation profile of the semilunar valve consisting of the leaflets (VL), indicated by three crosses. The uppermost point indicated by the cross is located within the commissure cell 117, and the lowermost point 111c is located between the most proximal cell 110, i.e., the two cells of the first middle cell row 111a aligned above the inflow row 110.

[0095] The commissure cells 117 of the distal-most cell row 114 of the prosthetic heart valve 100 shown in FIG. 1 are substantially diamond shaped and the separation cells 118 are substantially triangular shaped.

[0096] 1C, the stent frame 102 is shown in a tubular configuration and, as such, has a lumen 103, a luminal surface 104, and an abluminal surface 105. As can be further seen in this figure, the stent frame 102 in this embodiment includes five rows of cells, with the proximal-most row being the inflow end of the stent frame 102 and the distal-most row 114 being the outflow end of the stent frame 102.

[0097] Fig. 2 shows a schematic diagram of the skirt 130. In the assembled state of the prosthetic heart valve 100, the skirt 130 is attached / mounted to the luminal surface 104 of the stent frame 102 via the skirt body 131 and the first portion 133 of the skirt flap 132. For ease of understanding, the stent frame 102 in Fig. 1A and 1B is shown without the skirt 130 in Fig. 2 attached to the stent frame 102 and in an open / flat state rather than in a tubular configuration.

[0098] 2, the skirt includes a skirt body 131 and three skirt flaps 132, each of which is integrally formed with and extends from the skirt body 131 in a distal direction D. In the assembled state of the prosthetic heart valve of the present invention, the three skirt flaps 132 cover three commissure cells 117 of the distal-most row 114 of the stent frame 102.

[0099] Each skirt flap 132 includes a first portion 133 and a second portion 134. Each first portion 133 includes an opening 135 (window or hole) that is located within a cell 117, i.e., a commissure cell, when the prosthetic heart valve of the present invention is assembled, i.e., when the skirt 130 is attached to the stent frame 102. To assemble the prosthetic heart valve of the present invention, the skirt 130 is attached to the luminal surface 104 of the stent frame 102 such that the skirt body 131 covers at least the most proximal cell row 110 from the inside of the lumen 103. The second portion 134 of each skirt flap 132 is designed to be folded back from the luminal surface 104 at the most distal end 116 (see FIG. 1) of the commissure cell 117, so that the second portion 134 is attached to the abluminal side of the stent frame 102. The attachment of the skirt 130 to the stent frame is shown in more detail in FIG. 4 and will be described in more detail below.

[0100] The schematic diagram of skirt 130 shown in FIG. 2 shows that the proximal-most contour 136, ie, the shape of skirt 130, matches the contour of the proximal-most contour 113 of stent framework 102.

[0101] Thus, in the assembled state of the prosthetic heart valve 100 of the present invention, the skirt is attached to the entire height of the stent frame 102 .

[0102] FIG. 3 shows a schematic diagram of a leaflet 121 of a valve element 120 (see FIG. 7 ) in one embodiment of a prosthetic heart valve 100 of the present invention, illustrating, by way of example, two different shapes (A) and (B) of a single leaflet 121 when not attached to a stent frame 102.

[0103] As shown in FIG. 3, each leaflet 121 includes a leaflet body 123 and two leaflet flaps 122 or wings. The leaflet body 123 is disposed in the lumen 103 of the stent frame 102. The leaflet flaps 122 are guided from the luminal surface 104 to the abluminal surface 105 of the stent frame 102 through the openings 135 of the skirt flaps 132, which are located in the respective commissure cells 117 covered by the respective skirt flaps 132, thereby fixing each leaflet 121 to the stent frame 102 via the decoupling elements 99. The leaflet flaps 122 are shaped and designed so that they can be guided through the openings 135 of the skirt flaps 132, as will be described below with reference to FIG. 4.

[0104] 3A and 3B, the leaflet flap 122 is shaped with a rounded free end that is located below the flap 122. The leaflet flap 122 has a beveled edge 125 that matches the cells of the stent framework.

[0105] FIG. 4 shows an enlarged partial view of the stent frame 102 and illustrates a step in a method for manufacturing a prosthetic heart valve 100 according to an embodiment of the present invention. FIG. 4A illustrates the alignment of the skirt 130 on the luminal surface 104 of the stent frame, with the skirt body 131 aligned in the lumen 103 to cover the proximal-most row 110, the first intermediate row 111a, and the second intermediate row 111b. As shown in FIG. 4, the first portion 133 of the skirt flap 132 is positioned to cover the commissure cells 117 of the distal-most row 114 of the stent frame 102 such that the opening 135 is located within the commissure cell 117. In this step, the second portion 134 of the skirt flap 132 extends in the distal direction D beyond the proximal-most end 116 of the commissure cell 117. In other words, the second portion 134 of the skirt flap 132 is in a state before being folded back toward the proximal-most end 116 of the commissure cell. Also, the leaflets 121 , and more specifically the leaflet flaps 122 or wings, are shown prior to being guided through the openings / holes 135 located in the commissure cells 117 .

[0106] In the next step shown in FIG. 4B , the leaflet 121, or more specifically the leaflet flap 122, is guided or pushed from the luminal surface 105 of the stent frame 102 through the openings 135 located in the commissure cells 117, folded back to the right and left sides of the openings 135, and guided to the abluminal surface 105 of the stent frame 102.

[0107] 4C, the second portion 134 of the skirt flap 132 is folded back over the proximal-most end 115 of the commissure cell 117 to at least partially cover the opening 135 and the leaflet flap 122. The second portion thus positioned can then be attached, for example by suturing, to the abluminal surface 105 of the stent frame 102, thereby securing the leaflets within the prosthetic heart valve. This unique method of securing allows the leaflets to be configured to not come into contact with the stent frame 102.

[0108] As defined in the claims, the leaflet attachment method shown in Fig. 4 increases the flexibility of the valve element since the leaflets are not coupled to the stent frame. In this way, the decoupling element 99 is formed by combining the skirt 130, the first part 133 of the skirt flap 132 covering the commissure cell 117 and including the opening 115, and the second part 134 of the skirt flap 132 folded over the leaflet flap 122 guided through the opening 115 (see Fig. 6).

[0109] FIG. 5 shows various embodiments for forming a decoupling element 99 with a skirt flap 132 relative to a stent frame 102 and attaching the skirt / skirt flap to the stent frame.

[0110] 5A-5C each show a schematic cross-sectional view of a portion of a stent frame 102 in one embodiment of a prosthetic heart valve 100 of the present invention, showing a portion of a leaflet 121 / leaflet flap 122 being guided through an opening 135 in a skirt flap 132 covering a commissure cell 117 in the distal-most row 114 of the stent frame 102. In FIG. 5, reference numeral 138 indicates a cross-section of a strut of a commissure cell in the distal-most row.

[0111] 5A shows an embodiment in which a first portion 133 of the skirt flap 132 covers the luminal side of the stent frame 102 and a second portion 134 of the skirt flap 132 covers the abluminal side of the stent frame 102. The skirt flap 132 is not guided to wrap around the struts 138 of the commissure cells. In this embodiment, the skirt body 131 is also attached to the luminal surface 104 of the stent frame 102.

[0112] 5B shows another embodiment for attaching the skirt elements to form the decoupling element 99. In this embodiment, a first portion 133 of the skirt flap 132 (and thus also the body 131 of the skirt 130 (not shown in FIG. 5)) is attached to the abluminal surface 105 of the stent frame 102, and a second portion 134 of the skirt flap 132 surrounds the struts 138 of the commissure cells. An opening 135 is formed in the luminal surface 104 of the stent frame 102, for example by not joining the two ends of the second portion 134 of the skirt flap 132 at the luminal surface 104.

[0113] FIG. 5C illustrates yet another embodiment for attaching the skirt elements to form the decoupling element 99. In this embodiment, a skirt body 131 is attached to the luminal surface 104 of the stent frame, and a first portion 133 of a skirt flap 132 is also attached to the luminal surface 104, and the first portion 133 of the skirt flap 132 is provided with an opening 135 located in the commissure cell 117. A second portion 134 of the skirt flap 132 is attached to the abluminal side of the stent frame 102 and surrounds the struts 138 of the commissure cell, covering the opening 135 on the abluminal side. As shown in FIG. 5C, the ends 134a and 135b of the second portion can overlap each other.

[0114] FIG. 6 shows a schematic diagram of the mechanism of the decoupling element 99. FIG. 6A shows a front view, and FIG. 6B shows a cross-sectional view cut through the stent frame 102. As shown diagrammatically, the decoupling element 99 (see above) provides a flexible "suspension" for the leaflets of the prosthetic heart valve 100 of the present invention, and is representatively shown by the spring element 90. In the embodiment shown in FIG. 4, the decoupling element is provided by attachment of the leaflets via a skirt flap 132 covering the commissure cell 117. Thus, in this embodiment, the skirt (more specifically the skirt portion) covering the commissure cell 117 serves as a suspension for the commissure spring element. In this way, as described above, flexible commissures can be provided by decoupling the leaflets from the stent frame 102 itself and the movement of the stent frame 102, resulting in increased flexibility of the valve element compared to direct attachment to the stent frame and its struts.

[0115] FIG. 7 shows a diagram of one embodiment of the assembled prosthetic heart valve of the present invention. In the embodiment shown in FIG. 7, a valve element 120 having three leaflets 121 is shown. The valve element 120 is mounted in the lumen 103 of the stent frame 102. A skirt 130 with a skirt body 131 is mounted in the lumen 103 of the stent frame 120 and covers the proximal-most row 110, the first intermediate row 111a, and the second intermediate row 111b from the luminal side. The separated cells 118 of the distal-most cell row 114 are not covered by the skirt, but the commissure cells 117 of the distal-most row 114 are covered from the luminal surface 103 by a first portion 133 of a skirt flap 132 and from the external surface by a second portion 134 of the skirt flap 132, which is folded back at the distal-most end of the commissure cells 117. The skirt is attached to the struts that form the cells of the stent frame by being sewn to the stent frame with sutures. The cells of the distal-most cell row 114 that are not covered by the skirt, as well as the intermediate row 112 immediately adjacent to the distal-most row 114, provide sufficient space for outflow.

Claims

1. 1. A prosthetic heart valve (100) for implantation in a patient's heart, comprising: a stent frame (102) including a lumen (103), luminal and abluminal surfaces (104; 105), and a plurality of cells arranged in circumferentially aligned rows (110; 111; 112; 114); a valve element (120) attached to the prosthetic heart valve (100) and including at least two, and preferably three, leaflets (121); A skirt (130) attached to the stent frame (102); Including, the plurality of cells includes at least a proximal-most row of cells (110), at least one intermediate row of cells (112), and a distal-most row of cells (114); The skirt (130) includes a skirt body (131) and at least two, preferably three, skirt flaps (132) that are integral with or attached to the skirt body (131); the skirt body (131) covers at least the proximal-most cell row (110); each skirt flap (132) covering a corresponding one of the commissure cells (117) of the distal-most cell row (114) to form a decoupling element (99); the leaflets (121) are attached to the prosthetic heart valve (100) within the commissure cells (117) of the distal-most cell row (114) via respective decoupling elements (99); Artificial heart valve.

2. 2. The prosthetic heart valve of claim 1, wherein each skirt flap (132) includes an opening (135) disposed within a commissure cell (117) covered by each skirt flap (132).

3. 3. The prosthetic heart valve of claim 1, wherein each skirt flap (132) comprises a first portion (133) and a second portion (134), the first portion (133) having an opening (135) disposed in the at least one commissure cell (117), and the second portion (134) is attached to the abluminal side of the stent frame (102) by being folded back at a distal-most end (116) of the commissure cell (117) and designed to cover at least a portion of the opening (135).

4. 4. The prosthetic heart valve according to claim 1, wherein the skirt body (131) is attached to the luminal surface (104) of the stent frame (102), each skirt flap (132) comprising a first portion (133) and a second portion (134), the first portion (133) being attached to the abluminal surface (105) of the stent frame and the second portion (134) being attached to the luminal side of the stent frame (102) by folding back from the abluminal surface (105) of the stent frame around a lateral strut (138) of a commissure cell (117), and the opening (135) is designed to be formed in the luminal surface (104).

5. 4. The prosthetic heart valve according to claim 1, wherein each skirt flap (132) comprises a first portion (133) and a second portion (134), the first portion (133) being attached to the luminal surface (104) and comprising an opening (135) arranged in the at least one commissure cell (117), and the second portion (134) being designed to cover at least a portion of the opening (135) by being folded back from the luminal surface (104) of the stent frame (102) around a lateral strut (138) of the commissure cell (117) and attached to the abluminal side of the stent frame (102).

6. 10. The prosthetic heart valve according to claim 1, wherein each leaflet (121) comprises a leaflet body (123) and a leaflet flap (122), the leaflet body (123) being disposed within the lumen of the stent frame (102), the leaflet flap (122) being guided from the luminal surface to the abluminal surface (105) of the stent frame (102) through an opening (135) disposed within the commissure cell (117) covered by the skirt flap (132), and each leaflet (121) is fixed to the stent frame (102) via the decoupling element.

7. 11. The prosthetic heart valve of claim 1, wherein the distal-most cell row (114) includes at least two, and preferably three, commissure cells (117), which are separated from each other by separation cells (118), and the commissure cells (117) are longer than the separation cells (118) and therefore protrude in the distal direction D.

8. 8. The prosthetic heart valve of claim 7, wherein the commissure cells (117) are substantially diamond shaped and the separation cells (118) are substantially triangular shaped.

9. 10. The prosthetic heart valve of any one of the preceding claims, wherein the proximal-most row of cells (110) comprises substantially heart-shaped cells (119).

10. 10. The prosthetic heart valve of claim 1, wherein the stent frame includes an intermediate row (112) immediately adjacent the distal-most row (114), the intermediate row (112) preferably including substantially triangular cells.

11. 10. The prosthetic heart valve of claim 1, wherein the stent frame comprises a first intermediate row (111a) immediately adjacent to the proximal-most row (110), the first intermediate row (111a) preferably comprising substantially hexagonal cells, and wherein the stent frame comprises a second intermediate row (111b) immediately adjacent to the first intermediate row (111a), the second intermediate row (111b) preferably comprising substantially hexagonal cells.

12. 10. The prosthetic heart valve of any one of the preceding claims, wherein the skirt (130) comprises a fabric, film or tissue material having a predetermined flexibility, preferably a material selected from polyester, polyurethane and PTFE.

13. 10. The prosthetic heart valve of claim 1, wherein the skirt body (131) of the skirt (130) is provided on the luminal surface (104) of the stent frame (102), each first portion (133) of the skirt flap (132) is provided on the luminal surface (104) of the stent frame (102), and each second portion (133) of the skirt flap (132) is provided on the abluminal surface (105) of the stent frame (102).

14. 10. The prosthetic heart valve of any one of the preceding claims, wherein the stent frame (102) is a balloon-expandable stent frame or a self-expandable stent frame.

15. A method of manufacturing a prosthetic heart valve (100), comprising the steps of: providing a stent frame including a plurality of cells arranged in circumferentially aligned rows, the plurality of cells including at least a proximal-most row of cells, a middle row of cells, and a distal-most row of cells, a lumen, and a luminal surface and an abluminal surface; a step of attaching, preferably by sewing, a skirt comprising a skirt body and at least two, preferably three, skirt flaps integral with the skirt body to the stent frame, such that the skirt body covers at least the proximal-most cell row on the luminal surface of the stent frame, a first portion of each skirt flap including an opening covers cells of the distal-most cell row on the luminal surface of the stent frame, and a second portion of each skirt flap is positioned to extend beyond the distal-most end of the cell covered by the first portion; attaching at least two, preferably three leaflets, including a leaflet body and a leaflet flap, to the stent frame, such that the leaflet body is disposed within the lumen of the stent frame, and the leaflet flap is guided from the luminal surface to the abluminal surface of the stent frame through an opening in a first portion of the skirt flap; folding back a second portion of each skirt flap at a distal-most end of the cell covered by the first portion of the corresponding skirt flap to cover the leaflet flap and at least a portion of the opening with the second portion; Attaching a second portion of the skirt flap to the stent frame to secure the leaflets to the stent frame via a decoupling element. A method comprising:

16. 16. The method of claim 15, wherein each leaflet includes two flaps that are guided through the opening in a folded state, unfolded after passing through the opening, and then covered by the second portion of the skirt flap.

17. The method according to claim 15 or 16, wherein a prosthetic heart valve according to any one of claims 1 to 14 is produced.

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