Balloon dilation type pediatric surgery heart valve

Abstract

The present disclosure describes a prosthetic surgical heart valve for smaller patients, particularly pediatric patients. The heart valve is smaller and more flexible, and can incrementally expand to accommodate growth of the patient. The heart valves are particularly useful at pulmonary valve locations where opening and closing pressures are much lower than at other native valve locations. The heart valves are formed from a thinner and more flexible material than the aortic or mitral valve, which enables them to be opened and closed more efficiently when subjected to lower pulmonary blood flow pressures. Incremental expansion of the heart valve is achieved by a stiffener coupled to plastic expansion of the valve member.

Description

Technical Field

[0001] This application generally relates to expandable surgical pulmonary valves for adolescents, children and infants. Background Technology

[0002] In vertebrates, the heart is a hollow muscular organ with four pumping chambers: the left and right atria and the left and right ventricles, each with its own one-way valve. Natural heart valves are identified as the aortic valve, mitral valve (or bicuspid), tricuspid valve, and pulmonary valve, each with flexible leaflets extending inward from a fibrous annulus, which interlock to prevent backflow.

[0003] Prostheses exist to correct problems associated with damaged heart valves. For example, mechanical and tissue-based heart valve prostheses can be used to replace damaged natural heart valves. Efforts have been made to develop replacement heart valves, particularly tissue-based replacement heart valves. Recently, pediatric heart valve replacement surgery has become increasingly common, typically for the pulmonary valve (pulmonary artery), located between the right ventricle and the pulmonary artery. Pulmonary valve problems in children can occur alone or in conjunction with other heart conditions present at birth (congenital heart defects), such as tetralogy of Fallot.

[0004] However, because most heart valve replacements are required for advanced heart disease in older patients, particularly the mitral and aortic valves, the most common valve implants and technological advancements are too advanced and not well-suited for pediatric patients with smaller annular or vessel diameters. For example, a retrospective review of all patients who underwent pulmonary valve replacement with stented bioprosthetics from 1992 to 2008 was reported in "Bioprosthetic pulmonary valve replacement: Contemporary analysis of a large, single-center series of 170 cases," Chen et al., Vol. 146, No. 6, 2013, *Journal of Thoracic and Cardiovascular Surgery*. One conclusion drawn was that common techniques that result in oversized stented bioprosthetics would be disadvantageous in smaller, younger patients. In younger patients, even the smallest available stented bioprosthetic valve (19 mm) would be too large, as a 19 mm pulmonary valve has a body surface area greater than 1 m². 2 The normal valve diameter of the patient is approximately the average for a 10-year-old child.

[0005] Therefore, a better understanding of the technical challenges in pediatric heart valve replacement surgery is needed, and valves should be improved accordingly. Summary of the Invention

[0006] This application provides exemplary prosthetic heart valves designed for smaller patients, particularly pediatric patients. The prosthetic heart valves are manufactured to be smaller and more flexible, and can be incrementally expanded to accommodate the patient's growth. The heart valves are particularly useful at the pulmonary valve location, where the opening and closing pressures are much lower than at other natural valve locations. Therefore, the heart valves are formed from thinner and more flexible materials, which allows them to open and close more effectively under lower pulmonary blood flow pressures.

[0007] A first embodiment of a prosthetic heart valve suitable for surgical delivery and implantation at a natural valve annulus includes a valve member having a leaflet support structure defining a plurality of upright commissures alternating with an equal number of arched tips to define a wavy outflow edge. The valve member has a plurality of flexible leaflets extending along and attaching to the wavy outflow edge, the flexible leaflets merging with each other to form a unidirectional valve across an internal flow orifice defining a central axis. The support structure is formed of a malleable expandable material. A reinforcing band juxtaposed against the inflow end of the valve member defines a generally annular shape having an initial diameter sufficient for the valve to function. The reinforcing band is formed of a malleable expandable material that cannot be compressed to less than the initial diameter but is capable of expanding in diameter by at least 2 mm. Finally, a fabric covering is disposed around the valve member and the reinforcing band, wherein the fabric covering and / or the stitches connecting the fabric covering to the valve member and the reinforcing band provide a unique connection structure between the valve member and the reinforcing band, and there are no other non-fabric components between them.

[0008] A second exemplary prosthetic heart valve suitable for surgical delivery and implantation at a natural valve annulus has a valve member having a leaflet support structure defining a plurality of upright commissures alternating with an equal number of arched tips to define a wavy outflow edge. The valve member also has a plurality of flexible leaflets extending along and attached to the wavy outflow edge, the leaflets merging with each other to form a unidirectional valve across an internal flow orifice defining a central axis. The support structure is formed of a malleable expandable material, and each leaflet has a thickness t between about 0.004 and 0.013 inches (0.10 to 0.33 mm). A reinforcing band juxtaposed against and coupled to the inflow end of the valve member defines a generally annular shape having an initial diameter sufficient for the valve to function. The reinforcing band is formed of a malleable expandable material that cannot be compressed to less than the initial diameter but is capable of expanding in diameter by at least 2 mm. Finally, a fabric covering is placed around the valve member and the reinforcing band.

[0009] Another exemplary prosthetic heart valve suitable for surgical delivery and implantation at a natural valve annulus includes a valve member having a leaflet-supporting linear structure defining a plurality of upright commissures alternating with an equal number of arched tips to define a wavy outflow edge. The linear structure has a line diameter d between about 0.009 and 0.019 inches (about 0.23 to 0.48 mm). The valve member has a plurality of flexible leaflets extending along and attached to the wavy outflow edge, the flexible leaflets merging with each other across an internal flow orifice defining a central axis to form a unidirectional valve. The linear structure is formed of an expandable material. A reinforcing band juxtaposed against and coupled to the inflow end of the valve member defines a generally annular shape having an initial diameter sufficient for the valve to function. The reinforcing band is formed of a malleable expandable material that cannot be compressed to a size smaller than the initial diameter, but can expand in diameter by at least 2 mm. Similarly, a fabric covering is disposed around the valve member and the reinforcing band.

[0010] The method disclosed in this article for surgically implanting a prosthetic heart valve at the natural pulmonary valve annulus and enlarging the size of the implanted prosthetic heart valve includes the following steps:

[0011] Provide a prosthetic heart valve, said prosthetic heart valve having:

[0012] A valve assembly having a leaflet support structure defining a plurality of upright junctions alternating with an equal number of arched tips to define a wavy outflow edge; the valve assembly having a plurality of flexible leaflets extending along and attached to the wavy outflow edge; the plurality of flexible leaflets merging with each other and forming a one-way valve through an internal flow orifice defining a central axis; the support structure being formed of a malleable expandable material.

[0013] A reinforcing band, juxtaposed against the inflow end of the valve member, defines a generally annular shape having an initial diameter sufficient for the valve to function, and is formed of a malleable expandable material and cannot be compressed to a size smaller than the initial diameter; the reinforcing band is capable of expanding in diameter by at least 2 mm.

[0014] A fabric covering surrounding the valve member and the reinforcing band, wherein the fabric covering or the seam connecting the fabric covering provides a unique connection structure between the valve member and the reinforcing band;

[0015] The prosthetic heart valve is surgically delivered and implanted at the natural pulmonary valve annulus by dilating the prosthetic heart valve;

[0016] After implanting the prosthetic heart valve at the natural pulmonary valve annulus, the patient's incision was sutured.

[0017] Periodically measure the size of the natural pulmonary valve annulus or an analogue of said size; and

[0018] When the size or similar reaches a threshold value, an expansion balloon is advanced within the prosthetic heart valve and the balloon is inflated to plastically expand the valve assembly and reinforcing band and to expand the internal flow orifice by at least 2 mm.

[0019] This application also discloses a method for surgically implanting a first prosthetic heart valve at a natural pulmonary valve annulus and then implanting a second prosthetic heart valve within the first prosthetic heart valve, the method comprising:

[0020] A first prosthetic heart valve is provided, the first prosthetic heart valve having:

[0021] A valve assembly having a leaflet support structure defining a plurality of upright junctions alternating with an equal number of arched tips to define a wavy outflow edge; the valve assembly having a plurality of flexible leaflets extending along and attached to the wavy outflow edge; the plurality of flexible leaflets merging with each other and forming a one-way valve through an internal flow orifice defining a central axis; the support structure being formed of a malleable expandable material.

[0022] A reinforcing band, juxtaposed against the inflow end of the valve member, defines a generally annular shape having an initial diameter sufficient for the valve to function, and is formed of a malleable expandable material and cannot be compressed to a size smaller than the initial diameter; the reinforcing band is capable of expanding in diameter by at least 2 mm.

[0023] A fabric covering surrounding the valve member and the reinforcing band, wherein the fabric covering or the seam connecting the fabric covering provides a unique connection structure between the valve member and the reinforcing band;

[0024] The first prosthetic heart valve is surgically delivered and implanted at the natural pulmonary valve annulus by dilating the first prosthetic heart valve;

[0025] After the first prosthetic heart valve was implanted at the natural pulmonary valve annulus, the patient's incision was sutured.

[0026] Periodically monitor the valvular function of the first prosthetic heart valve; and

[0027] When the valve function weakens to below the threshold performance, an expansion balloon is advanced together with the second prosthetic heart valve into the position within the first prosthetic heart valve, and the balloon is inflated to plastically expand the second prosthetic heart valve outward and expand the internal flow orifice of the first prosthetic heart valve by at least 2 mm, while the second prosthetic heart is installed inside the first prosthetic heart valve.

[0028] Some examples include prosthetic heart valves with a linear structure made of cobalt-chromium alloy (or other malleable metals such as titanium alloys, stainless steel, etc.) covered with polyester fabric. Flexible bioprosthetic leaflets are attached to the linear structure in a conventional manner. For example, the frame is smaller than a conventional aortic valve, and the diameter of the wire used is much smaller than that of traditional surgical linear structures. Reducing the wire diameter, stiffness, and mass allows the frame to bend at pulmonary valve closure pressures at least five times lower than those of the aortic valve, thereby improving valve performance. Examples of valve leaflets are made from porcine or bovine pericardium with a thickness of less than about 0.35 mm (about 0.014"). The reduced mass and thickness of the leaflets also increase the valve response at low pressures.

[0029] The valve may also have an expandable reinforcing band that can increase the valve inflow diameter by more than 8 mm at a pressure of 6 atm, similar to a balloon. In some cases, the diameter of the reinforcing band can be incrementally expanded to accommodate the patient's growth or to accommodate a percutaneous valve subsequently implanted in a so-called valve-in-valve procedure. This feature will enable the valve size to be percutaneously increased by at least two valve sizes prior to replacement; for example, 2 mm then 4 mm, etc. Thus, an exemplary valve diameter may initially be 13 mm and can be expanded to 15 mm at different times, and then to 19 mm. The reinforcing band may be as small as 10 mm ID (11 mm OD) and expandable to accommodate a transcatheter valve of approximately 20 mm.

[0030] A further understanding of the properties and advantages will become apparent by referring to the remainder of the instruction manual and the diagrams. Attached Figure Description

[0031] The features and advantages will become clearer with reference to the specification, claims, and drawings, in which:

[0032] Figure 1 It is a cross-sectional view of the heart's circulatory system, showing all four natural valves;

[0033] Figure 2 This is an enlarged cross-sectional view of a current-tech prosthetic heart valve implanted at the aortic valve annulus;

[0034] Figure 3 This is a perspective view of an exemplary prosthetic heart valve in the prior art;

[0035] Figures 4A to 4D yes Figure 3 Cross-sectional views and detailed diagrams of a prosthetic heart valve illustrate certain exemplary construction aspects;

[0036] Figure 5 This is an enlarged cross-sectional view of the prosthetic heart valve of this application implanted at the natural pulmonary valve annulus;

[0037] Figure 6 This is a front view of the prosthetic heart valve of this application;

[0038] Figure 7 yes Figure 6 A front view of the two main structural components of a prosthetic heart valve;

[0039] Figure 8 It is formed Figure 6 A perspective view of an exemplary leaflet support linear structure of one of the structural components of a prosthetic heart valve;

[0040] Figure 9 It is formed Figure 6 A perspective view of an exemplary expandable reinforcing band in another of the structural components of a prosthetic heart valve;

[0041] Figures 10A to 10C This is a front view of the reinforcing bands at different stages of expansion;

[0042] Figure 11A yes Figure 6 A cross-sectional view of a prosthetic heart valve, showing certain exemplary construction aspects, and Figure 11B It is an enlarged view of one of its connected columns; and

[0043] Figure 12A and 12B yes Figure 6 The image shows a front view of a prosthetic heart valve with the outer fabric covering and sealing ring removed, and also shows its initial and subsequent expansion states. Detailed Implementation

[0044] Currently, for pediatric valve replacement surgery, and particularly for pulmonary valve placement, there is typically a limited number of options or no options at all. Most valves used for pediatric valve replacement are designed for adult aortic valve replacement. These valves are usually too large and designed to withstand closing pressures exceeding 120 mmHg, at least five times the closing pressure of the pulmonary valve. Because of their size and design for higher pressures, these valves perform poorly when used to replace the pulmonary valve in infants.

[0045] Figure 1 This is an overall cross-sectional view of the circulatory system of the heart in diastole, showing all four natural valves. The right ventricle (RV) and left ventricle (LV) are separated from the right atrium (RA) and left atrium (LA) by the tricuspid valve (TV) and mitral valve (MV), respectively (e.g., atrioventricular valves). Additionally, the aortic valve (AV) separates the left ventricle (LV) from the ascending aorta (AA), and the pulmonary valve (PV) separates the right ventricle from the pulmonary artery (PA) (commonly referred to as the pulmonary trunk). Each of these valves has flexible leaflets that extend inward from the fibrous annulus across a corresponding orifice, which converge or “clasp” together in the flow to form a one-way fluid-blocking surface. The prosthetic heart valve of this application is primarily intended for replacement of the pulmonary valve (PV), but it should be understood that the device described herein can also be used to replace other valves.

[0046] The cardiac cycle involves collecting deoxygenated or venous blood from the right side of the heart and forcing it into the lungs, then transporting the now-oxygenated blood from the lungs through the left side of the heart and back into the circulatory system. The right atrium (RA) receives deoxygenated blood from the venous system via the superior vena cava (SVC) and inferior vena cava (IVC), as well as other veins (shown as shallower). During diastole or relaxation, such as Figure 1 As observed, venous blood collected in the right atrium (RA) is drawn through the tricuspid valve (TV) by the expansion of the right ventricle (RV). Similarly, oxygenated blood (shown as lighter) is drawn through the mitral valve (MV) by the expansion of the left ventricle (LV). During systole (not shown), the myocardium compresses and the right ventricle (RV) collapses to force venous blood through the pulmonary valve (PV) and pulmonary artery (PA) into the lungs. Likewise, the left ventricle (LV) collapses to force oxygenated blood through the aortic valve (AV), through the ascending aorta (AA), and into the circulatory system. During systole, the leaflets of the four valves are positioned relative to... Figure 1 The positions shown are relative.

[0047] Figure 2 This is an enlarged cross-sectional view of a prior art prosthetic heart valve 20 implanted at the aortic valve annulus, and... Figure 3 This is a perspective view of an exemplary bioprosthetic heart valve. Heart valve 20 is shown as a so-called "hybrid" prosthetic heart valve 20, comprising an upper valve member 22 attached to a fabric-covered anchoring skirt 24. The anchoring skirt 24 is typically a malleably expandable metal frame formed by struts, but it can also be self-expanding. Details of such hybrid valves are found in more detail in U.S. Patent Publication No. 2017 / 0000604, which is expressly incorporated herein for all purposes. Although a hybrid prosthetic heart valve is shown for comparison with the prior art, conventional bioprosthetic surgical valves are constructed in a similar manner but without the anchoring skirt.

[0048] The valve component 22 of the hybrid prosthetic heart valve 20 has three upright commissural posts 28 projecting toward the outflow end along the flow axis, which alternate with three arched tips 30 curving toward the inflow end. As shown, blood flows upward from the left atrium LA through the aortic valve and the ascending aorta AA, thus the inflow end is downward and the outflow end is upward. Three flexible leaflets 32 are supported by the commissural posts 28 and tips 30 and extend across a generally cylindrical flow orifice defined therein to form a unidirectional occlusion surface. While three leaflets and three corresponding commissural posts 28 and tips 30 are conventional, two or more are possible, and therefore the valve described herein can have multiple flexible leaflets. Furthermore, the flexible leaflets 32 are ideally biological prostheses, such as bovine or porcine, but other biomaterials and synthetic materials may also be used.

[0049] In the illustrated example, the heart valve 20 also includes a highly fitted sealing ring 36 that extends outward from the heart valve at approximately the interface between the valve member 22 and the anchoring skirt 24. The sealing ring 36 may be a fabric-covered silicone or fabric cuff, which, once implanted, helps prevent leakage around the valve. Furthermore, the sealing ring 36 is suture-permeable and can be used to secure the valve in place within the natural valve annulus or blood vessel. In the illustrated example, the natural aortic leaflets have been removed so that the sealing ring 36 is positioned on the ring above the fibrous flange defining the aortic valve annulus. Alternatively, the aortic leaflets are sometimes left in place and simply compressed between the valve and the valve annulus.

[0050] Figures 4A to 4D yes Figure 3 The cross-sectional and detailed views of the prosthetic heart valve 20 illustrate certain exemplary construction aspects. Three flexible leaflets 32 are partially supported by a wavy linear structure 40 and a structural scaffold 42. The linear structure 40 may be formed of a metal such as a cobalt-chromium alloy or nitinol, while the structural scaffold 42 may be metal, plastic, or a combination of both. The linear structure 40 and the structural scaffold 42 are conventionally covered with polyester fabric to facilitate assembly and reduce direct blood exposure after implantation.

[0051] Figure 4C and 4D An exemplary internal structural scaffold 42 is shown in exploded and assembled views. The structural scaffold 42 specifically illustrated is used in pericardial heart valves manufactured by Edwards Lifesciences of Irvine, CA. Edwards' Perimount® heart valve family utilizes a bovine pericardial leaflet 32 ​​with a two-part internal scaffold 42 comprising an assembly or complex of two concentric bands (outer band 46 surrounding inner band 48). Bands 46 and 48 are relatively thin in the radial dimension compared to their axial dimension, and both have overlapping lower edges that undulate axially around the circumference. The outer band 46 exhibits three truncated peaks 50 between three downward-curving valleys or tips 52, while the inner band 48 has a generally similar shape but also extends upward at the commissural post 54. The outer band 46 of the Edwards valve is metallic and can be formed from strips connected by suturing 56, while the inner band 49 is a molded polymer piece, so that the syndesm 54 is highly flexible and facilitates inward movement of the leaflet. Sutures can be used to join the two bands 46, 48 together.

[0052] Other commercially available surgical prosthetic heart valves of the prior art utilize an internal, one-piece stent formed of polymer or metal and typically covered with fabric. For example, valves sold by Medtronic, Inc. of Minneapolis, MN, under the trademarks Hancock I™ or Hancock II™ and Mosaic™ and MosaicUltra™, have a polymer internal stent. On the other hand, the Trifecta™ stented tissue valve sold by St. Jude Medical, Inc. of St. Paul, MN, has a titanium stent. The internal, one-piece stent again provides the main structural framework of the valve and, like Edwards' valve, includes a thin-walled tubular member having a lower circular band extending around the periphery of the stent, and multiple upright syndesm columns. As with other conventional valves, there are three syndesm columns, each supporting two adjacent leaflets. It should be understood that leaflet and support structure constructions other than those shown can be used in the prosthetic valves described herein.

[0053] A particularly useful leaflet support is found in Edwards' Perimount® heart valve series, which results in lower stress in the pericardial leaflet 32. For example... Figure 4B As seen, the outer flaps 58 of adjacent leaflets 32 are wrapped around the flexible connecting post 54 of the structural support 42 at the valve suture. Specifically, each leaflet 32 ​​has an outwardly pointing flap 58 that passes under the U-shaped upright post of the linear structure 40 and radiates from the adjacent flap 58 around the corresponding connecting post 54. The flaps 58 are then secured in this position using sutures, which may pass through the pores in the connecting post 54, such as... Figure 4C As seen, other commercial valves omit the linear structure, and therefore the bioprosthetic leaflets are supported only by the synaptic columns of the internal scaffold.

[0054] Figure 4BThe thickness t of the leaflet 32 ​​and the line diameter d of the elongated line of the linear structure 40 are indicated. Conventional prosthetic surgical heart valves have a total diameter of 19–33 mm, typically in 2 mm increments. The leaflet 32 ​​used in such valves has a varying thickness, usually due to the variability of the xenogeneic porcine or bovine material used. However, for leaflets 32 made from bovine pericardial sheets of more uniform thickness, the thickness t is typically in the range of 0.014–0.023 inches. The linear structure 40 may have a line diameter d between 0.020–0.026 inches. These dimensions are suitable for heart valves used in aortic or mitral valve locations where blood flow pressures are relatively high, but not for pulmonary locations where pressures are several orders of magnitude lower. The relatively bulky and rigid surgical valves of the prior art, even the smallest diameter versions, tend to perform poorly in pulmonary valve replacement.

[0055] Figure 5 This is an enlarged cross-sectional view of the prosthetic heart valve 120 of this application implanted at the location of the natural pulmonary valve. Various aspects of the prosthetic heart valve 120, particularly its overall dimensions and the dimensions of certain components, are particularly useful at the natural pulmonary valve annulus, but the valve can also be used at other natural annulus locations. The heart valve 120 is configured similarly to a “hybrid” prosthetic heart valve 120 and has an upper valve member 122 coupled to a fabric-covered reinforcing band 124 juxtaposed against the inflow end of the valve member. The reinforcing band 124 is typically a malleably expandable metal frame formed by struts. If a malleably expandable metal frame is used, the reinforcing band 124 can be expanded by inflating a balloon therein. Preferably, the balloon is inserted all the way into the flow orifice of the heart valve 120, causing both the valve member 122 and the reinforcing band 124 to expand radially in equal proportions.

[0056] like Figure 6 As seen, the valve assembly 122 has three upright syndesmates 128 projecting toward the outflow end along the flow axis, which alternate with three arched tips 130 curving toward the inflow end. As illustrated, blood flows upward from the right ventricle (RV) through the pulmonary valve (PV) and pulmonary artery (PA), thus the inflow end is downward and the outflow end is upward. The three flexible leaflets 132 are supported by the syndesmates 128 and tips 130 and extend across a generally cylindrical flow orifice defined therein to form a unidirectional occlusion surface. While three leaflets and three corresponding syndesmates 128 and tips 130 are conventional, two or more are possible, and therefore the valve described herein can have multiple flexible leaflets. Furthermore, the flexible leaflets 132 are ideally biological prostheses, such as those from cattle or pigs, but other biomaterials and synthetic materials may also be used.

[0057] In the illustrated example, the heart valve 120 also includes a highly fitted sealing ring 136 that extends outward from the heart valve at approximately the interface between the valve member 122 and the reinforcing band 124. The sealing ring 136 may be a fabric-covered silicone or fabric cuff, which, once implanted, helps prevent leakage around the valve. Furthermore, the sealing ring 136 is suture-permeable and can be used to secure the valve in place within the natural valve annulus or blood vessel. In the illustrated example, the natural pulmonary valve leaflet has been removed so that the sealing ring 136 is positioned on the ring above the fibrous flange defining the pulmonary valve annulus. Alternatively, the leaflet is sometimes left in place and simply compressed between the valve and the valve annulus.

[0058] The reinforcing band 124 shown has a plurality of (preferably three) downwardly projecting connecting posts 140, which alternate with a plurality of upwardly curved pointed edges. These shapes are formed by an internal member that defines the reinforcing band 124 covered in fabric 144, as will be described in more detail below. The fabric cover 144 may surround only the internal member, or it may be shared by both the sealing ring 136 and the internal member.

[0059] Figure 7 yes Figure 6 A front view of the two main structural components of a prosthetic heart valve; that is, Figure 8 An exemplary leaflet support linear structure 150 is shown, and Figure 9 The internal components defining an expandable reinforcing band 124 are shown, which is juxtaposed against the inflow end of a linear structure. The linear structure 150 has an exaggerated wavy shape, having multiple (e.g., three) upright ferrules 152 alternating with the same number of arched tips 154. The linear structure 150 defines the outflow end of a heart valve 120, with the ferrules 152 extending toward the outflow end and the tips 154 curving toward the inflow end of the valve. The linear structure 150 is composed of elongated, continuous linear elements such that both the ferrules 152 and the tips 154 define a U-shaped portion, wherein the ferrules are significantly narrower and higher in the axial dimension than the tips. When rotated about a central axis, the linear structure 150 defines a tubular or slightly conical surface of rotation.

[0060] Linear structure 150 represents an annular support within valve member 122, providing a wavy structural shape around which flexible leaflets 132 are attached. This shape allows leaflets 132 to function as a one-way fluid-blocking surface within the flow orifice defined by valve member 122. As mentioned above, prior art prosthetic valves, such as those available from Edwards Lifesciences, Medtronic, Inc., and St. Jude Medical, Inc., have different styles of internal leaflet support members, and linear structure 150 can be replaced by many different structures. However, an advantageous aspect is that regardless of the annular leaflet support member used, it is flexible together with reinforcing band 124 to allow for radial expansion. For example, U.S. Patent No. 10,543,085, explicitly incorporated herein, describes many such valve support members that can expand to facilitate valve-in-valve surgery. In addition to enabling valve-in-valve surgery, the expandability of the Heart Valve 120 also provides the ability to expand the valve in stages after implantation to accommodate the patient's structural growth. This becomes even more important when the patient is initially an infant or child and growth is inevitable. More information on this type of incremental valve expansion will be provided below.

[0061] Figure 7 Several small inserts 156, which can be used to fix the valve leaflet 132, are also shown in dashed lines. The inserts 156 are shown in dashed lines to emphasize that they provide only one means of fixing the leaflet 132. As... Figure 4D Similar to the flexible synaptic column 54 on the inner band 48 of the stent 42 seen in the diagram, the leaflet 132 may have a similar Figure 4B The leaflet flaps 58 are outwardly pointing flaps. They can be inserted below the U-shaped junction 152 and wrapped around and secured to the insert 156. However, because the insert 156 is a disconnecting element, they do not increase the annular stiffness of the valve 120.

[0062] One problem associated with pediatric heart valve replacement surgery is that when a valve is implanted in a child or adolescent, the patient's subsequent growth may cause the heart valve to become too small to perform its intended function, thereby abnormally constricting the valve annulus or blood vessel. Subsequent surgery is required to replace the initially implanted heart valve with a larger heart valve appropriate for the patient's size at that time. Therefore, a beneficial aspect of the heart valves 120 described herein is that they are expandable.

[0063] The reinforcing band 124 has an annular shape that defines a tubular rotating surface when rotated. The reinforcing band 124 includes an alternating series of solid plate segments and expandable segments around its periphery. That is, the band 124 has a series of plate segments 160 connected by expandable struts or linear elements. In the illustrated example, each expandable segment has an inflow peak 162 opposite to an outflow peak 164, the inflow peak and the outflow peak being connected to adjacent plate segments 160 via arched struts 166, 168, respectively. The combination of peaks 162, 164 and struts 166, 168 forms a slightly diamond-shaped arrangement of struts between the plate segments 160. A hole 170 may be provided through each of the plate segments 160 to facilitate the outer fabric covering 144 (…). Figure 6 ) is attached.

[0064] The plate segment 160 creates nodes or regions where the reinforcing band 124 cannot expand, with expansion occurring only within segments having expandable peaks 162, 164 and struts 166, 168. Preferably, the expanding segment is circumferentially centered or aligned with the U-shaped junction 152 of the linear structure 150, such that the junction 152 expands uniformly as the reinforcing band 124 expands. Conversely, the tip 154 ​​of the linear structure 150 is centered or aligned with the plate segment 160 and therefore does not experience expansion forces. The leaflets 132 are configured to function within the diameter range of the linear structure 150, for example, providing slightly larger or looser leaflets for the initial valve size, which can then accommodate some expansion while still being mated to each other. For example, the initial valve size may increase incrementally by 2 mm over time, and then by another 2 mm, and the leaflets 132 still serve to provide a unidirectional blood flow occlusion surface. The example is an initial size of 13 mm (“size” is the marked valve size or diameter corresponding to the measured flow orifice diameter), which can be increased to 15 mm over time, and then eventually to 19 mm.

[0065] The reinforcing band 124, which connects to the valve member 122 throughout the valve 120, can be as small as 10 mm ID (11 mm OD) and can be expanded to accommodate a 20 mm transcatheter valve. Depending on the design of the leaflet 132, there may be practical limitations on the extent of expansion, and for some patients, complete prosthetic valve resection and replacement may be required. Alternatively, because the valve 120 is expandable, it can indicate subsequent valve-in-valve procedures.

[0066] In the example shown, the plate segment 160 extends less around the circumference of the reinforcing band 124 than the interventional dilatation segment. For example, each plate segment 160 may extend around a span of approximately 30°, while each dilatation segment, including peaks 162, 164 and struts 166, 168, extends around approximately 90°. Typically, the angular span of each plate segment 160 is between approximately 17% and 75% of the span of one of the dilatation segments, and the absolute value is between approximately 15° and 50° over the entire circumference. This balance achieves significant dilatation while providing sufficient stiffness to the band 124 to maintain a specific diameter against the physiological forces associated with pulsating blood circulation and accompanying orifice bending. As mentioned, peaks 162, 164 and struts 166, 168 ideally form a rhomboid shape below each U-shaped junction 152 of the linear structure 150, wherein the upper peak or outflow peak 164 extends upward within the linear junction 152. In practice, the curvature of the arcuate peak 164 preferably mimics the curvature of the U-shaped commissure 152. The lower peak or inflow peak 162 is preferably a mirror image of the upper peak 164. Of course, as mentioned, the dilation segment can be configured in different ways, such as having multiple rows of dilatational struts, just like a conventional transcatheter valve stent.

[0067] As mentioned above, the structural components within valve assembly 122 are expandable, even if they can be incorporated with annular components, such as linear structure 150. It is noteworthy that valve 122 omits any rigid annular components, such as… Figure 4D The internal stent 42 shown is for Edwards's pericardial valve. The linear structure 150 is expandable and can be made of a malleable expandable material, such as a cobalt-chromium alloy, such as Elgiloy® alloy (or other malleable metals such as titanium alloys, stainless steel, etc.). Alternatively, the linear structure 150 can be formed of a flexible material, such as a flexible metal or polymer like nitinol, in which case the linear structure expands along the malleable expandable band 124. The internal components of the reinforcing band 124 are formed of a continuous strip of malleable expandable material such as stainless steel, titanium alloy, or cobalt-chromium alloy. Due to the expandable segments in the reinforcing band 124, it can expand to many different sizes.

[0068] Figures 10A to 10C This is a front view of the reinforcing band 124 at different stages of expansion. Figure 10A The reinforcing band 124 is shown before any expansion. Figure 10B It indicates an outward expansion to define the modified reinforcing band 124'. And finally, Figure 10C Further outward expansion is indicated to define another modified reinforcing band 124''. At each stage of expansion, the U-shaped peaks 162, 164 and connecting struts 166, 168 straighten slightly. By distributing the expandable segments around the reinforcing band 124, and particularly in the region corresponding to the commissural struts of the valve member 122, the heart valve 120 maintains its roundness and functionality.

[0069] It is important to understand that, unlike transcatheter valves which are compressed into a small profile and delivered through a catheter or other access tube, the prosthetic heart valve 120 of this application is configured for surgical delivery. That is, the reinforcing band 124 is formed of a malleable expandable material capable of expanding from its initial shape without compressing, such as… Figure 10A As shown. Of course, although excessive force could indeed pull the reinforcing band 124 from... Figure 10A The size of the tube can be compressed, but the tube will wrinkle and therefore become ineffective. Therefore, the term "suitable for surgical delivery" means that the heart valve cannot be compressed to pass through the tube and must be delivered with the patient in a cardiopulmonary shunt.

[0070] Figure 11A yes Figure 6 A cross-sectional view of the prosthetic heart valve 120, showing the side without the outer fabric covering 144, and Figure 11B This is an enlarged view of one of its connecting columns. Like the previously described surgical heart valves, the heart valve 120 incorporates the bovine pericardium into three individual leaflets 132, which are supported by three connecting portions 152 and tips 154 of a wavy linear structure 150. Each leaflet 132 has an outwardly extending tab 158 at an opposite end of its upper free edge 133. Figure 11B The leaflets 154 are slightly semi-circular in shape. The edge of the arcuate tip of each of the leaflets 132 is secured around the arcuate tip 154 ​​by stitching through the fabric covering 138 surrounding the linear structure 150. The tabs 158 of adjacent leaflets 132 extend below one of the linear junctions 152 and wrap around the insert 156. Stitches (not shown) are used to secure the tabs 156 to the insert 156.

[0071] Figure 11A The location of the sealing ring 136 is shown, situated radially outside the junction between the valve member 122 and the reinforcing band 124. The sealing ring 136 may be slightly undulating to match the wavy shape of the upper edge of the linear structure 150 and the reinforcing band 124. The sealing ring 136 also has a fabric cover 137, which may be shared with the valve member cover 138 or the reinforcing band cover 144, or the three covers may be separate pieces. In any case, the stitching between the fabric covers 137, 138, 144, or the individual covers, constitutes the structural connection between the valve member 122 and the reinforcing band 124. That is, Figure 7A linear structure 150 is shown above and structurally separated from the reinforcing band 124, with no other structural (e.g., non-woven) components between them. This flexible component facilitates the ability of the valve member 122 to bend inward and outward, and also helps to make the entire valve 120 more flexible when expansion to a larger diameter is required.

[0072] Figure 11B The thickness t of one of the leaflets 132 is indicated. For the pulmonary position, the total diameter of the valve 120 is reduced from that of a typical aortic or mitral valve, and the leaflets 132 are also reduced in thickness to allow for opening and closing from lower fluid pressure pulses. For example, the pulmonary valve closing pressure is at least 5 times lower than the pressure experienced at the aortic valve, between 4 and 6 atm. As mentioned above, the typical leaflet thickness of the aortic or mitral valve ranges from approximately 0.014 to 0.023 inches (approximately 0.36 to 0.58 mm). In contrast, the thickness t of one of the leaflets 132 of the pulmonary valve 120 is less than 0.014 inches, for example, between about 0.004 and 0.013 inches (about 0.1 to 0.33 mm). Similarly, the linear structure 150 has a smaller line diameter d between about 0.009 and 0.019 inches (about 0.23 to 0.48 mm), while the diameter of the linear structure used for the larger aortic or mitral valve is between about 0.02 and 0.026 inches (about 0.5 to 0.66 mm).

[0073] Figure 12A and 12B yes Figure 6 A front view of the prosthetic heart valve 120 without the outer fabric coverings 137, 138, 144 and the sealing ring 136 shows the initial state and the subsequent expanded state. The initial state may have a total diameter of 13 mm, while the expanded state may be 15 mm, or 19 mm after a second expansion. Considering the smaller pulmonary valve, the initial state is reached with a diameter of 11 mm. Due to the connection of the fabric coverings 137, 138, 144, the valve assembly 122 expands together with the reinforcing band 124, such as by inflating a balloon within the reinforcing band 124.

[0074] A method is proposed for surgically implanting a prosthetic heart valve at the natural pulmonary valve annulus and enlarging the size of the implanted prosthetic heart valve. The method involves procuring and preparing (e.g., providing) any prosthetic heart valve described herein. The prosthetic heart valve is surgically delivered and implanted at the natural pulmonary valve annulus by dilation, followed by suturing the patient's incision. Periodically, the size of the natural pulmonary valve annulus or an analogue of said size is measured. The analogue of size may be the size of one of other natural valve annulus that typically grows proportionally to the pulmonary valve annulus. When the size or analogue reaches a threshold value, such as when the size or analogue grows 2 mm or more, the prosthetic heart valve dilates. For example, a dilation balloon is advanced within the prosthetic heart valve, and the balloon dilates to plastically expand the valve components and reinforcing bands and dilate the internal flow orifice by at least 2 mm.

[0075] A method is also considered for surgically implanting a first prosthetic heart valve at the natural pulmonary valve annulus and then implanting a second prosthetic heart valve within the first prosthetic heart valve. The method involves procuring and preparing (e.g., providing) any prosthetic heart valve described herein. The prosthetic heart valve (first valve) is surgically delivered and implanted at the natural pulmonary valve annulus by dilating the prosthetic heart valve, followed by suturing the patient's incision. Valve function of the first prosthetic heart valve is periodically monitored, for example by echocardiography. If valve function deteriorates below a threshold performance level, such as when regurgitation is detected, the second valve is implanted in a valve-in-valve procedure. The valve-in-valve procedure begins by advancing an expansion balloon along with the second prosthetic heart valve to a position within the first prosthetic heart valve, and inflating the balloon to plastically dilate the second prosthetic heart valve outwards. This dilates the internal flow orifice of the first prosthetic heart valve by at least 2 mm while the second prosthetic heart is mounted within the first prosthetic heart valve.

[0076] While the foregoing is a complete description of preferred examples, various alternatives, modifications, and equivalents may be used. Furthermore, it will be apparent that certain other modifications may be practiced within the scope of the appended claims.

Claims

1. A prosthetic surgical heart valve suitable for surgical delivery and implantation at a natural annulus, comprising: A valve assembly having a leaflet support structure defining a plurality of upright junctions alternating with an equal number of arched tips to define a wavy outflow edge; the valve assembly having a plurality of flexible leaflets extending along and attached to the wavy outflow edge; the plurality of flexible leaflets merging with each other and forming a one-way valve through an internal flow orifice defining a central axis; the support structure being formed of a malleable expandable material. A reinforcing band is juxtaposed against the inlet end of the valve member, the reinforcing band defining a generally annular shape having an initial diameter sufficient to enable the valve to function, the reinforcing band being juxtaposed against the inlet end of the valve member, the reinforcing band being formed of a malleable expandable material and not compressible to a size smaller than the initial diameter, the reinforcing band being capable of expanding in diameter by at least 2 mm. as well as A fabric covering surrounding the valve member and the reinforcing band, wherein the fabric covering and / or the stitches connecting the fabric covering to the valve member and the reinforcing band provide a unique connection structure between the valve member and the reinforcing band, and there are no other non-fabric components between them.

2. The heart valve of claim 1, wherein the reinforcing band comprises an alternating series of solid plate segments and expandable segments surrounding its periphery.

3. The heart valve of claim 1, wherein the reinforcing band has a series of plate segments connected by expandable struts or linear elements.

4. The heart valve of claim 3, wherein each expandable segment has an inflow peak opposite to the outflow peak, the inflow peak and the outflow peak being connected to adjacent segments via an arcuate strut.

5. The heart valve of claim 4, wherein the inflow peak and outflow peak and the struts form a rhomboid arrangement of struts between the plate segments.

6. The heart valve of claim 3, wherein each of the plate segments has a plurality of holes therethrough for attachment of the fabric covering.

7. The heart valve of claim 1, wherein both the valve component and the reinforcing band are formed of a cobalt-chromium alloy.

8. The heart valve of claim 1, further comprising a sealing ring attached radially to the outer side of the junction between the valve member and the reinforcing band, the sealing ring having a fabric cover.

9. A prosthetic surgical heart valve suitable for surgical delivery and implantation at a natural annulus, comprising: A valve assembly having a leaflet support structure defining a plurality of upright commissures alternating with an equal number of arched tips to define a wavy outflow edge; the valve assembly having a plurality of flexible leaflets extending along and attached to the wavy outflow edge; the plurality of flexible leaflets merging with each other and crossing an internal flow orifice defining a central axis to form a unidirectional valve; the support structure being formed of a malleable expandable material; and each leaflet having a thickness t between approximately 0.004 and 0.013 inches (0.10 to 0.33 mm); A reinforcing band, which is juxtaposed against and connected to the inflow end of the valve member, defines a generally annular shape having an initial diameter sufficient to enable the valve to function. The reinforcing band is formed of a malleable expandable material and cannot be compressed to a size smaller than the initial diameter. The reinforcing band is capable of expanding in diameter by at least 2 mm. as well as A fabric covering that surrounds the valve component and the reinforcing band.

10. The heart valve of claim 9, wherein the reinforcing band comprises an alternating series of solid plate segments and expandable segments surrounding its periphery.

11. The heart valve of claim 9, wherein the reinforcing band has a series of plate segments connected by expandable struts or linear elements.

12. The heart valve of claim 11, wherein each expandable segment has an inflow peak opposite to the outflow peak, the inflow peak and the outflow peak being connected to adjacent plate segments via an arcuate strut.

13. The heart valve of claim 12, wherein the inflow peak and outflow peak and the struts form a rhomboid arrangement of struts between the plate segments.

14. The heart valve of claim 11, wherein each of the plate segments has a plurality of holes therethrough for attachment of the fabric covering.

15. The heart valve of claim 9, wherein both the valve component and the reinforcing band are formed of a cobalt-chromium alloy.

16. The heart valve of claim 9, further comprising a sealing ring attached radially to the outer side of the junction between the valve member and the reinforcing band, the sealing ring having a fabric cover.

17. A prosthetic heart valve surgery suitable for surgical delivery and implantation at the natural valve annulus, comprising: A valve assembly having a leaflet-supporting linear structure defining a plurality of upright commissures alternating with an equal number of arched tips to define a wavy outflow edge, the linear structure having a line diameter d between about 0.009 and 0.019 inches (about 0.23 to 0.48 mm), the valve assembly having a plurality of flexible leaflets extending along and attached to the wavy outflow edge, the plurality of flexible leaflets merging with each other and crossing an internal flow orifice defining a central axis to form a one-way valve, the linear structure being formed of an expandable material; A reinforcing band, which is juxtaposed against and connected to the inflow end of the valve member, defines a generally annular shape having an initial diameter sufficient to enable the valve to function. The reinforcing band is formed of a malleable expandable material and cannot be compressed to a size smaller than the initial diameter. The reinforcing band is capable of expanding in diameter by at least 2 mm. as well as A fabric covering that surrounds the valve component and the reinforcing band.

18. The heart valve of claim 17, wherein the reinforcing band comprises an alternating series of solid plate segments and expandable segments surrounding its periphery.

19. The heart valve of claim 17, wherein the reinforcing band has a series of plate segments connected by expandable struts or linear elements.

20. The heart valve of claim 19, wherein each expandable segment has an inflow peak opposite to the outflow peak, the inflow peak and the outflow peak being connected to adjacent plate segments via an arcuate strut.

21. The heart valve of claim 20, wherein the inflow peak and outflow peak and the struts form a rhomboid arrangement of struts between the plate segments.

22. The heart valve of claim 19, wherein each of the plate segments has a plurality of holes therethrough for attachment of the fabric covering.

23. The heart valve of claim 17, wherein both the valve component and the reinforcing band are formed of a cobalt-chromium alloy.

24. The heart valve of claim 17, further comprising a sealing ring attached radially to the outer side of the junction between the valve member and the reinforcing band, the sealing ring having a fabric cover.

25. A method for surgically implanting a prosthetic heart valve at the natural pulmonary valve annulus and enlarging the size of the implanted prosthetic heart valve, comprising: Provide a prosthetic heart valve, said prosthetic heart valve having: A valve assembly having a leaflet support structure defining a plurality of upright commissures alternating with an equal number of arched tips to define a wavy outflow edge, the valve assembly having a plurality of flexible leaflets extending along and attached to the wavy outflow edge, the plurality of flexible leaflets being opposed to each other to form a one-way valve across an internal flow orifice defining a central axis, the support structure being formed of a malleable expandable material; A reinforcing band is placed against the inflow end of the valve member, the reinforcing band defining a generally annular shape having an initial diameter sufficient to enable the valve to function, and the reinforcing band is formed of a malleable expandable material and cannot be compressed to a size smaller than the initial diameter, the reinforcing band being capable of expanding in diameter by at least 2 mm. as well as A fabric covering surrounding the valve member and the reinforcing band, wherein the fabric covering or the seam connecting the fabric covering provides a unique connection structure between the valve member and the reinforcing band; The prosthetic heart valve is surgically delivered and implanted at the natural pulmonary valve annulus by dilating the prosthetic heart valve; After implanting the prosthetic heart valve at the natural pulmonary valve annulus, the patient's incision was sutured. Periodically measure the size of the natural pulmonary valve annulus or an analogue of the size; as well as When the size or similar reaches a threshold value, an expansion balloon is advanced within the prosthetic heart valve and the balloon is inflated to plastically expand the valve assembly and reinforcing band and to expand the internal flow orifice by at least 2 mm.

26. A method of surgically implanting a first prosthetic heart valve at a natural pulmonary valve annulus and then implanting a second prosthetic heart valve within the first prosthetic heart valve, comprising: A first prosthetic heart valve is provided, the first prosthetic heart valve having: A valve assembly having a leaflet support structure defining a plurality of upright commissures alternating with an equal number of arched tips to define a wavy outflow edge, the valve assembly having a plurality of flexible leaflets extending along and attached to the wavy outflow edge, the plurality of flexible leaflets being opposed to each other to form a one-way valve across an internal flow orifice defining a central axis, the support structure being formed of a malleable expandable material; A reinforcing band is placed against the inflow end of the valve member, the reinforcing band defining a generally annular shape having an initial diameter sufficient to enable the valve to function, and the reinforcing band is formed of a malleable expandable material and cannot be compressed to a size smaller than the initial diameter, the reinforcing band being capable of expanding in diameter by at least 2 mm. as well as A fabric covering surrounding the valve member and the reinforcing band, wherein the fabric covering or the seam connecting the fabric covering provides a unique connection structure between the valve member and the reinforcing band; The first prosthetic heart valve is surgically delivered and implanted at the natural pulmonary valve annulus by dilating the first prosthetic heart valve; After the first prosthetic heart valve was implanted at the natural pulmonary valve annulus, the patient's incision was sutured. Periodically monitor the valve function of the first prosthetic heart valve; as well as When the valve function weakens to below the threshold performance, an expansion balloon is advanced together with the second prosthetic heart valve into the position within the first prosthetic heart valve, and the balloon is inflated to plastically expand the second prosthetic heart valve outward and expand the internal flow orifice of the first prosthetic heart valve by at least 2 mm, while the second prosthetic heart is installed inside the first prosthetic heart valve.

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