Valve prosthesis with a rotatable holding member

Abstract

A valve prosthesis for the heart comprises a prosthesis member (16) and a retaining member (18) for at least partially fixing the prosthesis member (16) to a part of the heart tissue in the implanted state of the valve prosthesis (10). The retaining member (18) comprises at least one component (22) having a main portion (24) coupled at an end (24a) to at least one connecting element (26) via a pivotable connection (30) for connecting the retaining member (18) to the prosthesis member (16). The connecting element (26) and the main portion (24) are pivotably connected to each other from a first position with minimal space requirements adapted for passage within a catheter to at least one second position taken at least in the implanted state of the prosthesis. Connecting members (34, 39; 54, 56) are provided to stably connect the main portion (24) and the connecting element (26) at the second position so as to limit the stress received by the flexible section under the operating conditions of the valve prosthesis.

Description

Technical Field

[0001] The present invention relates to the field of valve prostheses for cardiovascular valves.

[0002] The present invention has been developed with particular consideration for atrioventricular heart valves, i.e., mitral or tricuspid valve prostheses, which allow blood flow from the atrium to the ventricle during diastole and prevent backflow of blood in the reverse direction during systole, although not exclusively.

[0003] More specifically, the present invention relates to a valve prosthesis that can be implanted by a catheter-based percutaneous technique.

[0004] The present invention has been developed with particular consideration for a valve prosthesis having a rotatable retaining member.

Background Art

[0005] A prosthesis is an artificial device that is typically used to replace or at least integrate the function of a part of a defective or damaged organ and is implanted in a homologous position, i.e., placed in the natural position of a part of this organ. A heart valve prosthesis is used to direct the flow of blood in the heart in one direction. Atrioventricular heart valve prostheses, i.e., mitral or tricuspid valve prostheses, are used to regulate the flow of blood from the atrium to the ventricle of the heart during diastole and prevent backflow of blood in the reverse direction from the ventricle to the atrium of the heart during systole.

[0006] Heart valves can fall into a dysfunction that hinders their proper operation. Typically, the main dysfunctions of heart valves are valve regurgitation due to incomplete closure of the valve (e.g., insufficient healing between the valve leaflets due to prolapse of the valve annulus) and stenosis that limits the corresponding opening (e.g., due to calcification of the valve annulus). These dysfunctions can be caused by a variety of pathological conditions related to the same heart valve and / or the heart as a whole (e.g., degenerative diseases, ischemia, cardiomyopathy, congenital abnormalities, etc.). In this case, when the dysfunction cannot be treated by pharmacological routes or surgical repair of the heart valve, a corresponding replacement prosthesis is implanted in the heart.

[0007] The implantation of a heart valve prosthesis is a rather complex intervention. The open-chest implantation procedure of a cardiovascular prosthesis is particularly invasive and often requires interruption of the heartbeat and extracorporeal circulation of blood. Therefore, if possible and desirable, a percutaneous transcatheter method of accessing the heart through a minimally invasive peripheral access, such as the femoral artery, and implanting the prosthesis is preferred. For this purpose, the prosthesis is initially compressed radially. Generally, a guide system or delivery system including one or more catheters guides the prosthesis to the implantation site in the heart. When the prosthesis is placed in the correct position, it is released by the guide system and expands, for example, by the elastic return or inflation of a balloon disposed therein, and recovers to its operating dimensions.

[0008] Cardiovascular prostheses have been proposed that include a prosthesis member that supports the prosthesis valve leaflets and a retaining member that at least partially surrounds the prosthesis member to secure the prosthesis to a portion of the heart tissue. Some of these prostheses include a retaining member that cooperates with the prosthesis member to capture the native leaflets of the heart valve and thereby ensure secure fixation of the prosthesis. One of these prostheses is described in WO2012 / 063228 and WO2014 / 080339.

[0009] There is known a valve prosthesis in which a holding member is fixed to a prosthesis member when the prosthesis member is in a radially compressed configuration before being expanded into an operating configuration. Such a prosthesis is described in WO2015 / 118464. In one embodiment described in this document, the holding member of the prosthesis is constituted by sub-components, each of which has an articulation mechanism that allows elastic deformation until a configuration with minimal radial space requirements is achieved. In this way, the components of the holding member can be introduced and deployed into the implantation site within a small-diameter catheter, thereby making the procedure safer and minimizing invasiveness. More specifically, each sub-component comprises a central portion coupled to two ends via a transition zone that functions as a unidirectional joint, allowing re-alignment of the ends in the same plane as the rest of the sub-component in one direction, but preventing large deflections at a predetermined angle between the main plane of the sub-component and the axis of the prosthesis member in the opposite direction when the sub-component is reconnected to the prosthesis member.

[0010] A transseptal implantation procedure using such a prosthesis is described, for example, in WO2021 / 014400.

[0011] The structure of the retaining member of the prosthesis described in WO2015 / 118464 has been found to be particularly effective in avoiding the risk that segments of the retaining member (or containment portion) deflect excessively towards the inside of the ventricular cavity. In this way, when the prosthesis is finally released, both the fact that the retaining member continues to contact the native valve annulus and the correct mutual alignment between the retaining member and the central member of the prosthesis are guaranteed. However, when the prosthesis is implanted, a variable load related to the heartbeat is always applied to the transition region that functions as a joint or hinge between the central part and each of the ends of the sub-components, resulting in the generation of a periodic stress state, and the transition region needs to meet specific requirements regarding fatigue resistance for the large number of cycles applied over the expected operating years of the prosthesis. Therefore, with respect to what is described in WO2015 / 118464, there is a need to develop an improved solution that enables the same function of the retaining member, particularly its sub-components, while at the same time guaranteeing an increase in resistance to fatigue stress to improve its performance level and reliability. SUMMARY OF THE INVENTION

[0012] An object of the present invention is to overcome the drawbacks of the prior art with a valve prosthesis for a heart valve that is resistant and durable to the periodic stress due to the activity of the heart.

[0013] Another object of the present invention is to provide a valve prosthesis with a high level of durability and reliability over a long period.

[0014] Another object is to provide a heart valve with a retaining member that guarantees effective fixation and retention of the heart valve in the desired position.

[0015] Another object is to provide a heart valve with a retaining member that simultaneously has resistance, reliability, and durability with respect to the fatigue stress at a large number of cycles resulting particularly from the heartbeat and the pressure applied to the prosthesis by the blood flow generated by the opening and closing of the valve tips of the prosthesis valve.

[0016] Another object of the present invention is to provide a holding member for a heart valve prosthesis that is easy to install in a catheter-based procedure, particularly with respect to the placement of the holding member on atrioventricular valves such as the mitral valve and the tricuspid valve.

[0017] Another object of the present invention is to provide a holding member for a heart valve that is easy to manufacture, assemble, and use.

[0018] These and other objects and advantages are achieved by the present invention as defined in the appended claims.

[0019] In a first aspect, a valve prosthesis for a heart valve is described. The valve prosthesis includes a prosthesis member that supports a prosthesis valve cusp capable of reproducing the function of the cusp of the original heart valve. The valve prosthesis includes a holding member intended to at least partially fix the prosthesis member to a portion of heart tissue in a state where the prosthesis is implanted. In this state, the prosthesis is subjected to continuous stress due to the heartbeat that causes the opening and closing of the valve cusp, particularly to direct the blood flow in one direction.

[0020] The holding member described may comprise one or more components. Each component may have at least one connecting element. By one or more of these connecting elements, the holding member may be connected to the prosthesis member at least in a state where the valve prosthesis is implanted. Each component of the holding member may have at least one main portion, and this main portion is coupled at one end thereof to the at least one connecting element via a pivotable connection for connecting the holding member to the prosthesis member. A method of angularly orienting the connecting element with respect to the main portion of the component of the holding member is further described by the pivotable connection between the connecting element and the main portion of the component.

[0021] More specifically, an explanation will be given as to how this pivotable connection defines a joint or hinge between the connecting element and the main part of the component. By means of the joint, the connecting element can move, in particular by pivoting relative to the main part, in order to move from a first position to at least one second position. The first position can be defined, for example, as the position in which the connecting element and the main part of the component take on a configuration with minimal space requirements adapted for passage within the catheter. The term "minimal space requirements" is intended to be understood as meaning the lateral space requirements with respect to the sliding direction within this catheter, or more generally within the delivery device used in the transcatheter implantation procedure. A particularly effective configuration with minimal space requirements is one in which the connecting element is substantially aligned with the corresponding end of the main part, i.e., a configuration in which the longitudinal axis of the connecting element coincides substantially with the longitudinal axis of the main part at the connection end with respect to the connecting element itself.

[0022] The second position may be the position occupied by the holding member in the implanted state of the prosthesis, or more generally a position close to the implanted state of the prosthesis. This second position may coincide with the maximum deflection position of the joint, i.e., the limit angular position beyond which the connecting element can deflect relative to the end of the main part, but not necessarily so. In other words, the range in which the joint defined between the connecting element and the end of the main part moves from the initial position with minimal space requirements is preferably in a straight line but not necessarily so, is determined and predefined, and is located at the maximum limit that functions for correct implantation of the prosthesis.

[0023] In the above-described second position taken by the holding member in the implanted state of the prosthesis, the connecting element is oriented substantially transversely thereto in a manner that, for example, but not limited to, deflects relative to the corresponding end of the main part. The joint can be configured, preferably with an integral connection, such that the connecting element is substantially blocked relative to the main part at least in this second position, which may in some cases be a connection by a mechanical connection or an interlocking connection. In this regard, an explanation will be given as to how a connecting member can be provided to stably connect the main part and the connecting element at least in the above-described second position so as to limit the stress that the flexible section undergoes under the operating conditions of the valve prosthesis by the components of the holding member. The connecting member serves to provide an additional mechanical connection between the main part and the connecting element at the implantation position, which may be a position close to or substantially coinciding with the position where the connecting element is deflected maximally relative to the main part. This solution thus functions as a hinge and, therefore, strengthens the pivoting system of the connecting element so as to reduce the stress on the flexible section of the pivoting connection provided such that the components of the holding member are relatively elastic or flexible at the position occupied in the implanted configuration of the valve prosthesis, achieving a significant improvement over the prior art. Advantageously, this results in a structurally stable and robust configuration for the transition zone that functions as a hinge or joint of the holding member at the implantation position, guaranteeing requirements including robustness and resistance to the periodic stresses arising from heart activity, with its duration being significantly extended, and thus improving the reliability of the entire valve prosthesis over the long term.

[0024] The joint may be connected, for example, by the aforementioned integral connection, and in some cases, by a mechanical connection or an interlocking connection. When the connecting element is substantially blocked at a second position relative to the main part, the block can be released, for example, during the positioning procedure of the retaining member or, more generally, during the implantation procedure of the valve prosthesis, by an operation performed on the retaining member, one or more of its components, one or more main parts of the components, and / or one or more connecting elements, for example, after applying rotation and / or a predetermined pressing to one or more of them. Further, or alternatively, the joint may be configured such that it is necessary to apply rotation and / or a predetermined pressing to the retaining member, one or more of its components, one or more main parts of the components, and / or one or more connecting elements to block the connecting element. These features ensure a certain degree of freedom of operation for correctly positioning the retaining member during the implantation procedure, and the joint can be blocked in the final implant position only when its correct position has been confirmed.

[0025] In a particular aspect, although not necessarily dependent on the above, it is also explained that the pivotal connection defining the joint between the connecting element and the main part can comprise at least one flexible section. The flexible section thereby maintains the physical continuity between the main part and the connecting element. According to a particular aspect, the flexible section is arranged in the outer region of the joint, i.e., in the region of the component of the retaining member that takes a larger radius of curvature when the joint is bent and the connecting element is deflected. In this way, the physical continuity between the main part and the connecting element is arranged in the region that most contributes to the robustness of the joint and thus to its reliability and resistance over time.

[0026] In certain embodiments, the flexible section that can define a joint may be in the form of a flexible plate and includes a first portion having a first cross-section and a second portion having a second cross-section larger than the first cross-section, and a method for defining a relatively less resistant portion and a relatively more resistant portion respectively is described. Different cross-sections can be accurately and easily constructed by cuts made to the structure of the components of the retaining member.

[0027] In another particular embodiment, a method in which the flexible section is non-extensible is described. In particular, the flexible section may be integrally configured with the components of the retaining member so as to integrally form a main portion and a connecting element.

[0028] In certain embodiments, although not necessarily dependent on one or more of the above embodiments, the connecting member may comprise a system of wings that project laterally from the flexible section. The wings may be configured to engage at least one corresponding cavity formed in the connecting element. The wings may be supported within the cavity in an implanted configuration to create an additional mechanical connection between the connecting element and the main portion, which protects, and in fact eliminates, the deformable and vulnerable portions of the pivotable connection, particularly the flexible section, from the periodic exchange of loads between the elements of the annular structure.

[0029] In another particular embodiment, although not necessarily dependent on one or more of the above embodiments, a method in which the connecting element can pivot elastically is described. In particular, a method for elastically connecting the connecting element to the main portion of the components of the retaining member is described. Elastic pivoting is pivoting such that when the retaining member moves away from a first position, it is elastically pressed towards the first position. Elastic pivoting provides a particular feedback during the placement of the valve prosthesis when the retaining member exhibits resistance to the surrounding heart tissue, for example in the region of the annulus. Elastic pivoting may be blocked if the connecting member intervenes between the main portion and the connecting element at the implantation position of the valve prosthesis, for example, blocking the connecting element from pivoting relative to the main portion.

[0030] In another specific embodiment, which is not necessarily dependent on one or more of the above embodiments, the pivotable connection of the retaining member can be constructed by means of a cut and an opening in the tubular element. In this way, the structural continuity between the connecting element and the main part is advantageously maintained, enabling the use of a highly reliable processing technique based on laser cutting and the creation of a generally simple and economical manufacturing process. Preferably, the tubular element can completely define the component, resulting in economy and ease of manufacture. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Further features and advantages will be understood from the following detailed description of the preferred embodiments with reference to the accompanying drawings, which are provided purely by way of non-limiting example.

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

BEST MODE FOR CARRYING OUT THE INVENTION

[0032] In the following embodiments, features for implementing the present invention are described. The described features can be combined with each other in various ways and are not necessarily limited to the exact embodiments referred to in the drawings and the related description. In other words, those skilled in the art who read the following description can obtain useful information on how to implement one or more of the described features in combination with one or more of the other described features, but a particular expression in the description, paragraph, sentence, or drawing does not limit the possibility of separating one or more of the described and illustrated features and combining them with one or more of the other described and illustrated features. More specifically, in this specification, even if a feature is obtained individually from a particular context and combined or combined with other different features, any combination of any two explicitly described features should be understood to be explicitly described, considering the capabilities and knowledge of those skilled in the art in the relevant field who understand the possibility of functionally combining features without the need to functionally apply other different features. Unless otherwise specified, each and every element, member, means, system, component, object described and illustrated in this specification should be understood to be capable of autonomous change, separation, and / or combination from each and every other element, member, means, system, component, object described and illustrated. The materials, shapes, and functions described and illustrated are not intended to limit the present invention and are specified only to enable those skilled in the art to understand and implement the present invention according to preferred but non-exclusive embodiments.

[0033] Referring now to the drawings, FIG. 1 shows a valve prosthesis 10 for a heart valve. The valve prosthesis 10 is preferably used to replace the function of an atrioventricular valve, such as the mitral valve or the tricuspid valve. This type of valve prosthesis and methods for its implantation are described, for example, in WO2021 / 014400, the entire content of which is incorporated herein by reference.

[0034] The valve prosthesis 10 comprises a prosthesis structure 12 for supporting and connecting to a biological valve. A group of flexible prosthesis valve tips 14 are disposed within the prosthesis structure 12. The group of flexible prosthesis valve tips 14 are fixed to the prosthesis structure 12. The prosthesis structure 12 particularly comprises a prosthesis member 16, which is preferably tubular and supports the prosthesis valve tips 14 disposed within a tubular cavity. The prosthesis member 16 is surrounded by a retaining member 18 for at least partially fixing the prosthesis member 16 to a heart tissue portion in a state where the valve prosthesis 10 is implanted. In the illustrated exemplary embodiment, the retaining member completely surrounds the prosthesis member 16, forming a substantially closed ring, with the prosthesis member 16 disposed inside thereof. In a variant not shown, the retaining member may partially surround the prosthesis member, for example, forming an open C-shaped ring, or forming a plurality of turns to form a helical winding around the prosthesis member.

[0035] The retaining member 18 is stably fixed to the prosthesis member 16 via a connecting member 20. The retaining member 18 surrounds the original valve tip of the heart valve and is configured to oppose the radially expanding pressing force of the prosthesis member 16, such that in the final implanted configuration, the original heart valve remains captured between the outer surface of the prosthesis member 16 and the retaining member 18 in order to stably fix the valve prosthesis at a desired position within the heart.

[0036] The prosthesis structure 12 is configured to be foldable for each of its elements without any impact on the safety and functionality of the valve prosthesis. Thus, it is possible to temporarily reduce the radial space requirements of the valve prosthesis 10 to enable introduction into the heart cavity through an access port with a reduced opening, which is compatible with minimally invasive surgical techniques, catheter positioning and heart prosthesis implantation techniques, particularly catheter techniques involving transapical or transseptal access. Thus, the valve prosthesis 10 can be inserted into a catheter with a small radial outer shape and capable of transporting the prosthesis into the heart cavity near the implantation site through minimally invasive access, and deployed and implanted in place to functionally replace the original valve.

[0037] More specifically, the prosthesis member 16 is a part of the prosthesis structure 12 that defines a prosthesis conduit 13 for blood to pass through the device. Inside the prosthesis member 16, a flexible prosthesis valve tip 14 parallel to the longitudinal axis Z-Z of the prosthesis conduit 13 and directing the blood flow in the prosthesis conduit 13 in one direction is fixed. The prosthesis member 16 is preferably an elastic structure foldable radially with respect to the axis Z-Z, and for example, as a result of elastic recovery, attempts to expand to a diameter larger than the maximum diameter that maintains the junction, i.e., contact, between the free ends of the closed prosthesis valve tip 14. The radial expansion of the prosthesis member 16 with respect to the axis Z-Z is restricted by the retaining member 18 such that the original valve tip of the heart valve is captured between the outer surface of the prosthesis member 16 and the retaining member 18 as described above. In a variant, the prosthesis member 16 does not expand as a result of elastic recovery, but instead is forced to expand, for example, by inflating a balloon therein or by other techniques of a generally known type.

[0038] From the prosthesis member 16, a connecting member 20 that fixes the retaining member 18 to the prosthesis member 16 extends outwardly even when in a position still folded radially with respect to the axis Z-Z within the heart cavity.

[0039] The retaining member 18 is part of the prosthesis structure 12, resists and limits the free expansion of the prosthesis member 16, and prevents it from exceeding the maximum diameter compatible with maintaining the junction between the prosthesis valve tips 14. In other words, the retaining member 18 defines the perimeter of the maximum expansion of the prosthesis member 16, and when the prosthesis member 16 reaches this perimeter, it applies a force directed radially against the surrounding retaining member so that the native valve of the heart valve is captured and held clamped between the outer surface of the prosthesis member 16 and the retaining member 18. The retaining member 18 preferably has a substantially annular shape with a substantially non-extensible perimeter, that is, when a radial force is applied to the retaining member, the prosthesis member 16 expands and, even when the native valve tips are interposed, this does not significantly alter the deployment of its peripheral portion. The retaining member 18 can generally assume any two-dimensional or three-dimensional shape, either in accordance with or not in accordance with the anatomical structure of the native atrioventricular valve. In this second case, the retaining member can be elastically re-closed or can comprise a closing element, or can also maintain a partially open annular structure without the complete annular integrity being reconfigured in the implanted configuration of the valve prosthesis 10.

[0040] The retaining member 18 is composed of one or more components. Each component of the retaining member 18 can be provided and introduced into the heart cavity separately from the prosthesis valve 16 and then stably connected before expansion, whereby the valve prosthesis is stabilized in its final implanted configuration.

[0041] In another embodiment of the present invention, at least one component of the retaining member 18 can be pre-connected to the body of the prosthesis member 16 at one end via the connecting member 20, and the other end of the component can be left free. In this way, at least one component of the retaining member is introduced into the heart cavity together with the prosthesis member 16. Since it is introduced with an open end configuration, at least one component of the retaining member can be arranged to surround the natural valve leaflets of the heart valve. Thereafter, the free end of at least one component can be connected to the corresponding connecting member 20 to reconfigure the implanted annular structure.

[0042] In the non-limiting exemplary embodiment of FIG. 1, the retaining member 18 is formed by two components 22 that are independent of each other. The components 22 are provided with connecting members 26, and the connecting members 26 engage with the connecting members 20, and the connecting members 20 extend from the prosthesis member 16 and are adapted to fix it to the retaining member 18. The components 22 preferably each have an elongated shape with a main arcuate portion 24, and the main arcuate portion 24 is in the form of substantially two half-rings located in the same plane, and the plane is substantially perpendicular to the axis Z-Z. However, it is not excluded that the retaining member may be formed by a single component such as, for example, a closed ring, a helix, a partially open ring, or a ring that is initially open and can then close again around the prosthesis member 16. Similarly, it is not excluded that the retaining member 18 may be composed of more than three components. When the retaining member 18 is formed by a plurality of components, they may have the same length, dimensions, for example, cross-section and / or thickness, and / or configuration, for example, curvature and / or in-plane or in-space deployment, for all or only some of the components of the retaining member 18, and they may be the same as each other or all or part of them may be different.

[0043] In a non-limiting exemplary embodiment of FIG. 1, each component 22 has two respective connection elements 26 at its ends. Each connection element 26 preferably has a hollow structure, more preferably is constituted by a hollow structure, but in a particularly non-limiting manner, is substantially a hollow cylinder, and more preferably is a hollow cylinder having a circular cross-section. The hollow structure of the connection element 26 is configured such that a guide wire can pass through it freely.

[0044] The connection element 26 has a shape and dimensions such that it enables a stable connection to the connection member 20. The connection member 20 is preferably integrated with the prosthesis member 16 and protrudes outwardly around it, and for this purpose, a pair of pins 23 are respectively provided. The pins 23 are preferably parallel to each other and spaced sufficiently apart from each other, and are substantially aligned with the axis Z-Z of the prosthesis itself, such that the connection with the connection element 26 is enabled, particularly by being stably inserted into its hollow structure. Each pin 23 is also preferably hollow, such that a guide wire can slide freely through it, and preferably the same guide wire can also slide within the corresponding connection element 26.

[0045] In the final implanted configuration of the valve prosthesis 10 shown in FIG. 1, the connection elements 26 of each component 22 are oriented substantially perpendicular to the main plane in which the main part 24 is located. In other words, the connection elements 26 are parallel to the axis Z-Z. In this way, the holding member 18 is generally arranged in the same plane substantially perpendicular to the axis of the conduit 13 without harming the connection elements 26, and thus is substantially parallel to the native valve's annular plane (i.e., the plane defined by the annulus) when the structural unit of the valve prosthesis 10 is reconfigured. Engagement members such as plates, teeth, or other surface discontinuities that can increase friction or block the connection between the pin and the hollow structure of the connection element in a snap-fit manner can be provided on both the connection element 26 and the pin 23 present on the connection member 20 to improve the stability of the connection.

[0046] The structure of each component 22 of the retaining member 18 can have a passage for the guide wire along its entire length or at least a part thereof, preferably most of its entire length. In this way, the placement of the component 22 is made easier within the ventricular cavity behind the original valve tip. In fact, with known intervention techniques currently used clinically, it is sufficient to place the guide wire along the path defined by the desired placement of the segment and introduce this member by sliding it over the guide wire itself.

[0047] Figure 2 shows an enlarged view of one possible embodiment of the component 22 of the retaining member 18 in a preferred form of the elongated component. This embodiment is particularly suitable for the implantation procedure performed by transcatheter techniques. In particular, the embodiment of the component 22 shown in Figure 2 refers to the case where the retaining member 18 is divided into two components. In any case, the following description is equally applicable when the retaining member 18 includes a different number of components 22, such as a single component or two or more components.

[0048] To simplify the figures, Figure 2 shows a single structural part of component 22 that forms the retaining member 18 of valve prosthesis 10. This structural part is substantially obtained by tubular element 27, the walls of which are formed with openings 28 in dimensions and positions such as to impart to the structure a desired elastic behavior that is anisotropic and can vary from section to section according to the position along the deployment of component 22. In the embodiment shown in Figure 2, the openings 28 of tubular element 27 define a set of two opposing ribs or backbones 29. One function of the backbones 29 is to impart to the component structural characteristics of longitudinal non-extensibility and rigidity with respect to out-of-plane deformation, which are advantageous for a particular application. Of course, it is possible to form different types of openings 28 than those shown. For example, in order to impart to the part particular characteristics of elastic response, it is possible to form openings 28 having a different shape and / or different dimensions and / or different positions than those shown. In an exemplary variant not shown, it is possible to form a single set of ribs 29.

[0049] The structure of the component 22 thus formed can then be formed as schematically shown in FIG. 2, where the main portion 24, in particular the backbone 29, is curved in order to take the shape selected for the retaining member 18. The connecting element 26 can be bent at an angle with respect to the main portion 24. The material most suitable for this type of structural component, which requires an optimum mechanical performance level due to the operation within the elastic range including large deformations, is in the range of superelastic alloys, such as equiatomic alloys of nickel and titanium, which is commercially known under the name Nitinol. During the construction process, this structure can be readily obtained from a tube of a selected alloy such as Nitinol, where openings 28 are formed, for example, by laser cutting. For example, the final shape, such as that shown in FIG. 2, can be specified by a heat treatment operation applied to the workpiece fixed in the die. In the completed component 22, in order to reduce the risk of damage to the original valve tip in the connection region to the valve prosthesis, the structure may be completely or only partially covered with a tissue of biological nature, such as an animal pericardium, or a tissue of artificial nature, such as PET fibers or PTFE fibers, or a polymeric material, such as a polyurethane or a silicone-containing elastomeric material, or a combination of two, such as a polymeric material covered on the inside with fibers.

[0050] Figure 2 clearly shows two preferably cylindrical connection elements 26 that are deflected outside the main plane in which the main part 24 of the component 22 is located. These connection elements 26 are involved in the connection mechanism of the prosthetic structure 12 of the valve prosthesis and are, in particular, preferably integrated with the prosthetic member 16 as described above and connected to the connecting member 20 that protrudes outward with respect to its periphery, which is an element of the component 22. The connection elements 26 are also referred to here as joints or hinges and are pivotally coupled to the main part 24 of the structure of the component 22 by a pivotable connection, generally denoted by 30. The joint 30 defines a connection that enables mutual pivoting between the connection element 26 and the corresponding end 24a of the main part 24. In the specific example of the figure, each joint 30 is defined in particular by the transition region between the main part 24 and each of the connection elements 26. In other words, in the preferred embodiment shown in the figure, since the joint 30 is formed integrally with the structural part of the main part 24 and the connection element 26, there is material continuity between the end 24a of the main part 24 of the component 22 and the corresponding connection element 26. Due to the joint 30, the connection element 26 can be articulated from a position where the longitudinal axis of the connection element 26 is located substantially in the same plane as the main part 24 of the component 22 and preferably substantially in line with the adjacent end 24a of the main part 24 to a position where the connection element 26 is deflected outside the main plane as shown in Figure 2. The joint 30 can bring the connection element 26 back into alignment with the plane of the main part 24, but is formed so that it cannot be deflected beyond a predetermined angle, such as about 90°, for example, in a non-limiting manner, with respect to this plane. This solution prevents a greater deflection with respect to this predetermined angle between the main plane of the component 22 and the axis Z-Z of the prosthesis when the component 22 is reconnected to the prosthetic member 16 of the valve prosthesis 10. In this way, when the valve prosthesis 10 is finally released, both the continuity of the contact of the holding member 18 with the original valve annulus and the correct mutual alignment between the holding member 18 and the prosthetic member 16 are ensured.

[0051] Figures 3 - 8 show in more detail a first embodiment of the joint 30, which in this particular case is shown as joint 30a. This embodiment is shown by way of example and does not limit the generality of the present invention in any way. The joint 30a is formed by a cut and an opening in the tubular element 27, whereby the structural continuity of the component 22 is maintained via a flexible plate 32 arranged in the region of the outer side of the joint 30a, i.e., the zone of the component 22 where the radius of curvature increases when the joint 30a is bent. In other words, the flexible plate 32 is the part of the tubular element 27 that provides a physical continuity between the main part 24 and the connecting element 26 via the corresponding joint 30a for any deflection angle of the connecting element 26.

[0052] The plate 32 can have different thicknesses and / or shapes at different lengths, thereby defining different functional purposes for each section or part of the plate itself. As a non-limiting example, in the embodiments shown in FIGS. 3-8, the flexible plate 32 has a constant thickness corresponding to the thickness of the tubular element 27 in which it is formed, and has a narrow section 32a coupled to the tubular section of the connecting element 26 and a wide section 32b coupled to the tubular section of the main portion 24. Between the narrow section 32a and the wide section 32b of the flexible plate 32, two wings 34 having arcuate edges 35 directed towards the wide section 32b extend laterally. The narrow section 32a is the most deformable part of the plate 32, i.e., the part that allows the flexion of the joint 30a with an acceptable level of stress of the material, thereby enabling the connecting element 26 to move between two extreme configurations, i.e., an extended configuration that is in the same plane as the main portion 24 and preferably aligned with its end 24a as shown in FIGS. 6-8, and a terminal deflection angle that is allowed by the shape of the joint 30a and, more generally, by any of the joints 30 described, in which region the joint can no longer deflect and has a substantially infinite angular rigidity, enabling movement from one to the other. The part having the two wings 34 has the purpose of engaging stably with the connecting element 26 by engaging in a shaped recess 37 formed in the edge of the connecting element 26 itself, thereby allowing the wings 34 to be connected to the shoulders 39 delimiting this recess. For this purpose, the radius of the main part of the contour 35 of the wings 34 is of the same order as the inner radius of the tubular element 27. The part having the two wings 34 is successively and firmly connected to the main portion 24 of the component 22 via the widest part 32b of the plate 32, which is characterized by a larger resistant section and is therefore more suitable for supporting and transmitting the periodic stresses applied to the holding member 18 during the operation of the prosthesis 10.

[0053] More specifically, when the joint 30a can assume the deflected configuration as shown in FIGS. 4 and 5, for example, when the valve prosthesis 10 is finally implanted, the arcuate edge 35 is intended to move and / or engage so as to abut against the corresponding inner wall 36 of the tubular element 27 in the region inside the joint 30a. In this position, the end lip 38 of the main part 24 is supported against the corresponding part of the wall 40 of the connecting element 26 arranged diametrically opposite to the plate 32. The same rear wall 40 or more generally the connecting element 26 may be formed with one or more tongue-like portions 42 for engaging with one of the pins 23 on the connecting member 20 as described above. The axial positioning of the lip 38 relative to the plate 32 defines a mechanical lock that results in the bending limit of the joint 30a and functions as an angular limit stopper. The connection between the wing 34 and the shoulder 39 of the forming recess 37 is supported by the inner wall 36 of the tubular element 27 and cooperates with the width of the cross-section of the most resistant part 32b of the plate 32, and sequentially moves so that its inner side abuts against the upper end of the wall 40 to also provide firm torsional stability to the joint 30a. Accordingly, the part of the joint 30a constituted by the part of the wing 34 and the most resistant part 32b of the plate 32 defines a resistant structural connecting element between the main part 24 of the component 22 and the connecting element 26.

[0054] FIGS. 9 and 10 show a variant of the joint 30b, also shown as a non-limiting example. In the figures, the same reference numerals correspond to the same elements as those described above. Also in this case, the joint 30b is formed by a cut and an opening in the tubular element 27 and maintains the structural continuity of the flexible plate 44 arranged in the region outside the joint 30b, that is, in the zone of the component 22 having the maximum radius of curvature when the joint 30b is bent. In other words, the flexible plate 44 is the part of the tubular element 27 that integrally couples the main part 24 to the connecting element 26 of the corresponding joint 30b.

[0055] In this variant, the flexible plate 44 preferably has the same width or thickness throughout, from the end joined to the tubular section of the connecting element 26 to the end joined to the tubular section of the main part 24. In a variant not shown, the flexible plate 44 is shaped in portions of different widths or thicknesses in order to impart a bending behavior with non-uniform curvature according to the method and characteristics shown in relation to the joint 30a above.

[0056] On the side opposite to the flexible plate 44, the tubular part of the connecting element 26 and the tubular part of the main part 24 are cut mirror-like, i.e., obliquely with respect to the axis of the tubular section, like the mouthpiece of a flute, so that two opposing support edges 46, 47 are defined. The two support edges 46, 47 are joined to each other by a narrow flexible section 48 obtained by enlarging with a slot 49 a longitudinal cut portion that defines the flexible plate 44 and separates it from the remaining part of the wall of the tubular element 27, near the flexible plate 44.

[0057] When the joint 30b is bent from the extended configuration shown by the solid line in FIG. 10 to the configuration adopted in the implanted prosthesis 10, the main part 24 rotates according to the arrow A so as to be brought to the broken line position 24', the two support edges 46, 47 move so as to abut against each other, defining a mechanical locking operation that limits the bending of the joint 30b and functioning as an angular limit stopper. At the same time, the two flexible sections 48, arranged transversely spaced on the transverse rotation axis of the main part 24 with respect to the connecting element 26, provide a robust torsional stability to the joint 30b. The transverse dimension of the section of the flexible plate 44 that at least partially counteracts the pivoting movement between the main part 24 and the connecting element 26 also contributes to this.

[0058] Figures 11 and 12 show another modification of the joint 30c, which is also shown as a non-limiting example. In the figures, the same reference numbers correspond to the same elements as described above. Also in this case, the joint 30c is formed by the cut and the opening of the tubular element 27 and maintains structural continuity through a flexible plate 50 arranged on the outside of the joint 30c, that is, in the region of the component 22 having the maximum radius of curvature when the joint 30c is bent. In other words, the flexible plate 50 is the part of the tubular element 27 that forms the physical continuity between the main part 24 of the corresponding joint 30c and the connecting element 26 for any deflection angle of the connecting element 26.

[0059] In this modification, the flexible plate 50 may have the same width or thickness throughout so as to exhibit the behavior and characteristics described above with respect to the joint 30a, or may be shaped with sections of different widths, thicknesses, or in any case different resistances in order to impart a bending behavior with non-uniform curvature. In the example of the figure, it is shown that the flexible plate 50 comprises a section 50a that is narrower and longer than the section 50b, thereby imparting different bending behaviors to the plate 50.

[0060] On the side opposite to the flexible plate 50, the tubular part of the connecting element 26 and the tubular part of the main part 24 are cut mirror-like, like the mouthpiece of a flute, that is, obliquely with respect to the axis of the tubular section, so that two support edges 52, 53 are defined. The support edge 52 formed at the end of the main part 24 extends until it is connected to the edge of the cut 54 that defines the part of the flexible plate 50 extending from the main part 24. The support edge 53 extends from the two parts of the connecting element 26 until it is connected to the two lateral recesses 54, forming two respective peaks 58. In the region of the recess 54, two wings 56 project from both sides of the flexible plate 50 towards the connecting element 26 and face each other in the direction of the recess 54.

[0061] When the joint 30c is bent from the extended configuration shown by the solid line in FIG. 12 so as to reach the configuration employed in the implanted prosthesis 10, the main portion 24 rotates according to arrow A so as to be brought to the broken line position 24', the two support edges 52, 53 move so as to abut against each other, defining a mechanical locking operation that limits the bending of the joint 30c and functioning as an angle limiting stopper. The design of the wing 56 is such that it slides within the recess defined by the edge of the notch 54 during this rotation of the joint 30c, but in any case remains supported at the peak 58, dispersing the stress transmitted from the main portion 24 of the component 22 to the connecting element 26 during the operation of the implanted prosthesis 10 to a larger resistance section. Thus, the wing 56 greatly contributes to the stability including the robustness, fatigue resistance, and torsional stability of the joint 30c. The flexible plate 50 that also counteracts the pivoting movement between the main portion 24 and the connecting element 26 also contributes to the overall robustness of the joint 30c.

[0062] In another variant of this embodiment of the invention, the design of the joint is such that, in the extended position shown by the solid line in FIG. 12, the end of the wing 56 interferes with each peak 58, preventing the joint 30c from bending in the direction opposite to arrow A, thereby stabilizing the fixing action, preventing errors during the assembly or installation of the component 22 and thus of the retaining member 18 of the valve prosthesis 10, or preventing the joint from bending excessively in a direction without angular mechanical locking means and subjecting the plate 50 itself to excessive stress.

[0063] In another variant of this embodiment of the invention, the design of the wing 56 and the notch 54 is such that, in the configuration employed in the prosthesis 10 in which the joint 30c is implanted, the wing 56 is fixed within each notch 54, blocking the joint 30c in the bent position and similarly improving the robustness and fatigue resistance, but also preventing the joint 30c from re-expanding to the extended position.

[0064] Figures 13 and 14 show another variant of the joint 30d, also shown as a non-limiting example. In the figures, the same reference numerals correspond to the same elements as described above. Also in this case, the joint 30d is constituted by a cut and an opening of the tubular element 27 that maintains the structural continuity of the flexible plate 60 located outside the joint 30d, as defined above. Also in this case, the flexible plate 60 is the part of the tubular element 27 that forms the physical continuity between the main part 24 of the corresponding joint 30d and the connecting element 26 for any deflection angle of the connecting element 26.

[0065] In this variant, the flexible plate 60 has the same width or thickness throughout. Of course, also in this case, the flexible plate 60 may be shaped in sections of different widths or thicknesses in order to impart a bending behavior with non-uniform curvature so as to take on the behavior and characteristics described above with respect to the joint 30a. On the opposite sides of the flexible plate 60, the tubular section of the connecting element 26 is shaped to have two protrusions 61 that respectively define hooks 62 on each side of the flexible plate 60. The protrusions 61 define each recess 64 connected to the edge 66 of the connecting element 26. At positions diametrically opposite on the flexible plate 60, the edge 66 has a protruding support lip 68.

[0066] At the ends of the main part 24, two protrusions 70 are formed, each provided with a hook 72 shaped to engage with each hook 62 and be inserted into its recess 64 at a position bent at approximately 90° of the joint 30d (not shown). At this bent position, the lip 68 moves to a state supported by a part of the rear wall 74 of the main part 24 at a position diametrically opposite to the flexible plate 60. The support between the lip 68 and the rear wall 74 forms a mechanical lock that defines the bending limit of the joint 30d and functions as an angular limit stopper. The engagement of the hooks 70 of the protrusions 61 with the hooks 62 gives the joint 30d a firm torsional rigidity, and the load transmitted to the connecting element 26 by the main part 24 of the component 22 is more dispersed.

[0067] The designs of the protrusions 61 and 70 and the contours of the recesses and hooks 62 and 72 can be changed to form different engagement methods between the two elements of the joint 30d and / or to enhance the supporting ability obtained by the surface connection.

[0068] Figures 15 and 16 show another variant of the joint 30e, also shown as a non-limiting example. In the figures, the same reference numerals correspond to the same elements as described above. Also in this case, the joint 30e is formed by a cut and an opening in the tubular element 27. In this embodiment, no flexible joint plate is provided, and the structural continuity between the main part 24 and the connecting element 26 is provided by two S-shaped wall sections 78 that are symmetric with respect to a longitudinal plane that faces and is orthogonal to the axis of rotation of the joint 30e. Each S-shaped wall section 78 is formed to form a first loop 80 on the connecting element 26. After forming the first loop 80, the S-shaped wall section 78 is bent to form a second loop 82, and at its end the S-shaped wall section 78 is joined to the main part 24. Extensions 84 are formed extending from the main part 24 and shaped to be respectively connected to one of the first loops 80 of the S-shaped wall sections 78 at a position bent approximately 90° of the joint 30e (not shown). At the bent position, the support lip 88 of the connecting element 26 is supported against a part of the rear wall 90 of the main part 24 located on the side of the extension 84. The support between the lip 88 and the rear wall 90 forms a mechanical locking action that defines the bending limit of the joint 30e and functions as an angular limit stopper. The engagement of the fingers 86 with the first loops 80 gives the joint 30e a robust torsional rigidity, and in particular, the load on the deformable part of the joint is significantly reduced with respect to the fatigue load transmitted by the main part 24 of the component 22 to the connecting element 26.

[0069] The proper design of the lateral fingers 86 and the contour of the loop 80 with geometric discontinuities, such as generating an undercut, can prevent the joint from returning from the bent position shown to the extended position by a permanent mechanical connection between the two elements, so that the joint can be made irreversible.

[0070] However, in FIGS. 15 and 16, despite the fact that the main part 24 with the finger 86 provided on the right side and the connecting element 26 with the first loop 80 formed on the left side are shown in the conventional manner, the possibility of reversing the joint 30e and forming the finger 86 on the connecting element 26 and the first loop 80 on the main part 24 is not excluded.

[0071] Of course, the principles of the present invention remain the same, and the details of the form and structure of the embodiments can be widely changed with respect to those described and illustrated without departing from the scope of the present invention.

Claims

1. A prosthetic member (16) supporting a prosthetic leaflet (14) capable of reproducing the function of the leaflet tip of a native heart valve, and A holding member (18) intended to at least partially fix the prosthetic member (16) to a part of the heart tissue in the implanted state of the valve prosthesis (10), and A valve prosthesis for a heart valve comprising: The holding member (18) comprises at least one component (22) having a main portion (24) coupled to at least one connecting element (26) at an end (24a) via a pivotable connection (30) for connecting the holding member (18) to the prosthetic member (16), The connecting element (26) and the main portion (24) are pivotably connected to each other so as to pivot from a first position to a second position, and the connecting element (26) is deflected with respect to the end (24a) of the main portion (24) in the second position, The component (22) further comprises connecting members (34, 39; 54, 56) for stably connecting the main portion (24) and the connecting element (26) in the second position so as to limit the stress received by the pivotable connection (30) under the operating conditions of the valve prosthesis, Valve prosthesis.

2. The pivotable connection (30) between the connecting element (26) and the main portion (24) comprises at least one flexible section (32, 44, 50, 60, 78) maintaining physical continuity between the main portion (24) and the connecting element (26), the valve prosthesis according to claim 1.

3. At least one flexible section (32, 44, 50, 60) is arranged outside the pivotable connection (30). The valve prosthesis according to claim 2.

4. A prosthetic member (16) supporting a prosthetic leaflet (14) capable of reproducing the function of the leaflet tip of a native heart valve, and A holding member (18) intended to at least partially fix the prosthetic member (16) to a part of the heart tissue in the implanted state of the valve prosthesis (10), and A valve prosthesis for a heart valve comprising: The holding member (18) comprises at least one component (22) having a main portion (24) coupled to at least one connecting element (26) at one end (24a) via a pivotable connection (30) for connecting the holding member (18) to the prosthetic member (16), The connecting element (26) and the main part (24) are pivotally connected to each other from a first position to at least one second position, and the connecting element (26) is deflected with respect to the end (24a) of the main part (24) in the second position. The pivotable connection (30) between the connecting element (26) and the main part (24) comprises, in its outer region, flexible sections (32, 44, 50, 60) that maintain the physical continuity between the main part (24) and the connecting element (26). Valve prosthesis. **Claim 5** The flexible section comprises a low-resistance part (32a, 50a) that provides a predetermined flexibility to the pivotable connection (30) during the movement from the first position to the second position, and a high-resistance part (32b, 50b) that defines the resistance to the stress received by the pivotable connection (30) with the valve prosthesis implanted. The valve prosthesis according to any one of claims 2 to 4. **Claim 6** The flexible section is a flexible plate (32, 50) comprising a first part (32a, 50a) having a first cross-section that respectively defines a low-resistance part and a high-resistance part, and a second part (32b, 50b) having a second cross-section larger than the first cross-section. The valve prosthesis according to claim 5. **Claim 7** The flexible section (32, 44, 50, 60) is non-extensible. The valve prosthesis according to any one of claims 2 to 6. **Claim 8** The flexible section (32, 44, 50, 60) is integrally formed with the component (22) and forms a single part together with the main part (24) and the connecting element (26). The valve prosthesis according to any one of claims 2 to 7. **Claim 9** The flexible section (32, 44, 50, 60) is arranged in the outer region of the pivotable connection (30) between the connecting element (26) and the main part (24). The valve prosthesis according to any one of claims 2 to 8. **Claim 10** When dependent on claim 3, the component (22) further comprises connection members (34, 39; 54, 56) for stably connecting the main part (24) and the connection element (26) in a second position so as to limit the stress received by the pivotable connection (30) under the operating conditions of the valve prosthesis, the connection members comprising wings (34) configured to project laterally from a flexible section and engage at least one corresponding recess (37) formed in the connection element (26), the valve prosthesis according to any one of claims 1 to 9.

11. The valve prosthesis according to any one of claims 1 to 10, wherein at least one connection element (26) is elastically connected to the main part (24) of the component (22) such that a thrust is applied to the component (22) in the direction of the first position.

12. The valve prosthesis according to any one of claims 1 to 11, wherein the pivotable connection (30) is formed by a cut and an opening in a tubular element (27) that maintains the structural continuity between the connection element (26) and the main part (24) of the component (22).

13. The valve prosthesis according to claim 12, wherein the tubular element (27) integrally defines the component (22).

14. The second position corresponds to at least the position of maximum deflection taken in the implanted state of the prosthesis, and the connection element (26) is deflected by a maximum angle such that it cannot be further deflected with respect to the end (24a) of the main part (24), the valve prosthesis according to any one of claims 1 to 13.

15. A method of implanting a valve prosthesis for a heart valve, comprising: - providing a prosthesis member (16) that supports a prosthesis valve tip (14) capable of reproducing the function of the valve tip of the original heart valve; - providing a holding member (18) intended to at least partially fix the prosthesis member (16) to a part of the heart tissue in the implanted state of the valve prosthesis (10), the holding member (18) comprising at least one component (22) having a main part (24) coupled to at least one connection element (26) at one end (24a) via a pivotable connection (30) for connecting the holding member (18) to the prosthesis member (16). - A step of configuring the connection element (26) and the main part (24) of the holding member (18) in a first position, wherein the connection element (26) and the main part (24) of the component (22) are configured with a minimum space requirement adapted to the passage in the catheter. - A step of introducing the component (22) into the heart cavity through the passage in the catheter. - A step of configuring the connection element (26) and the main part (24) of the holding member (18) in a second position, wherein the connection element (26) is deflected with respect to the end (24a) of the main part (24). - A step of stably connecting the main part (24) and the connection element (26) in the second position by connection members (34, 39; 54, 56) so as to limit the stress received by the pivotable connection (30) under the operating conditions of the valve prosthesis. - A step of introducing the prosthesis member (16) into the heart cavity. - A step of at least partially fixing the prosthesis member (16) by the holding member (18) to a part of the heart tissue to achieve the implanted state of the valve prosthesis (10). A method comprising the above steps.

Images