DE102022133681A1 - Minimally invasive implantable valve prosthesis and valve stent for connecting artificial valve leaflets - Google Patents

Abstract

The present invention relates to a valve stent for minimally invasive implantation in the human or animal body, comprising at least a tubular, mechanically compressible and deployable stent framework with an inflow opening and an outflow opening and one or more receiving frames for one or more valve leaflets integrated in the stent framework, wherein the receiving frames for the valve leaflets are aligned axially in the lateral surface of the tubular stent framework and the total axial length H of the receiving frames is less than or equal to the distance from the inflow opening to the outflow opening of the valve stent, wherein an area of greater than or equal to 25% of the maximum length H of the receiving frame in the direction of the outflow opening is not arranged on the stent framework and is freely movable radially relative to the stent framework. The present invention further relates to a valve prosthesis made of a valve stent according to the invention and one or more valve leaflets made of textile fabric.

Description

The present invention relates to a valve stent for minimally invasive implantation in the human or animal body, comprising at least a tubular, mechanically compressible and deployable stent framework with an inflow opening and an outflow opening and one or more receiving frames for one or more valve leaflets integrated in the stent framework, wherein the receiving frames for the valve leaflets are aligned axially in the lateral surface of the tubular stent framework and the total axial length H of the receiving frames is less than or equal to the distance from the inflow opening to the outflow opening of the valve stent, wherein an area of greater than or equal to 25% of the maximum length H of the receiving frame in the direction of the outflow opening is not arranged on the stent framework and is freely movable radially relative to the stent framework. The present invention further relates to a valve prosthesis made of a valve stent according to the invention and one or more valve leaflets made of textile fabric.

Medical progress, particularly in the last few decades, has made it possible to significantly extend the period of time available with an almost unchanged quality of life. A significant contribution to improving quality of life has been made by artificial replacement materials and parts made from them, which are able to temporarily or permanently take over the functions of body parts that are not working at all or only working inadequately. Examples include prostheses, which can be designed either in the form of static supports, for example in the hip area, or as movable functional supports, for example in the form of knee prostheses or heart valves. The latter prostheses in particular are subject to high technical requirements, as movable parts are exposed to a changing biomechanical load spectrum. This applies even more to heart valve prostheses, which must provide sufficient fatigue strength under mechanical stress for an estimated 200 million load cycles over a period of more than 5 years. Animal substitute materials in the form of porcine heart valves or porcine and bovine pericardial patches are usually used as valve leaflets to take over the functions. After decellularization, these materials consist essentially of collagen, which was designed by nature to provide the required long-term stability in the form of strength and elasticity. However, these inherently biocompatible materials tend to accumulate and deposit calcium under in-vivo conditions in the human body, which inevitably contributes to the stiffening and embrittlement of the valve leaflets over time. This disadvantage usually leads to a reduced service life of the prostheses used. For this reason, alternative materials would be desirable that have suitable mechanical and biological properties and can be manufactured in a standardized and reproducible manner. These materials should therefore not consist of animal materials, should not incorporate or deposit any of the body's own substances that impair function, and, ideally, should only have small variations in terms of mechanical properties. Furthermore, it would be desirable if these prostheses could be used in minimally invasive procedures to protect the patient group in question. The latter could, for example, avoid open-heart surgery and significantly shorten recovery times.

Different technical solutions for valve prostheses are also described in the patent literature.

For example, the WO 2010 124 219 A2 an expandable stent for use in implanting a prosthetic valve using a delivery system. The self-expandable stent comprises a tubular lattice structure defined by longitudinally aligned rods connected to V-shaped struts to form a plurality of interconnected zigzag-shaped six-sided polygons defining a distal end zone and a midzone of the tubular lattice structure. A flare or bend may be defined along opposite ends of each rod to properly position the stent and prosthetic valve during deployment and placement of the stent within the lumen and to prevent undue torsion.

Furthermore, the WO 2010 020 660A1 an implantable valve prosthesis, comprising at least one valve leaf and made from a material structure of unidirectional reinforcing elements made of stretched ultra-high molecular weight polyolefin, running in at least two directions, wherein the reinforcing elements consisting of polyolefin have a modulus of elasticity of at least 60 GPa, characterized in that the material structure consists of exactly one woven or knitted mesh of the reinforcing elements made of stretched ultra-high molecular weight polyolefin.

A further design is in the EP 1 804 726 B1 This describes a prosthetic heart valve for the functional replacement of a previously implanted prosthetic heart valve, wherein the prosthetic heart valve comprises a support structure (22); valve leaflets attached to the support structure; characterized by a device for coupling the prosthetic heart valve to a previously implanted prosthetic heart valve, wherein the device for coupling is connected to the support structure.

Such state-of-the-art solutions can still offer further potential for improvement. This particularly applies to the functional and long-lasting connection of valve materials to stent framework structures.

It is therefore the object of the present invention to at least partially overcome the disadvantages known from the prior art. It is in particular the object of the present invention to provide a valve stent which is reversibly compressible and expandable and which fixes artificial valve structures reliably and mechanically gently over longer periods of time. Furthermore, it is the object of the present invention to provide a valve prosthesis which can be implanted in a minimally invasive manner and which, due to the gentle connection of the valve structures, can provide a longer service life of the valve leaflets under cyclic load.

The problem is solved by the features of the independent claims, directed to the valve stent according to the invention and the valve prosthesis according to the invention. Preferred embodiments of the invention are specified in the subclaims, in the description or in the figures, whereby further features described or shown in the subclaims, in the description or in the figures can represent an object of the invention individually or in any combination, as long as the context does not clearly indicate the opposite.

According to the invention, a valve stent for minimally invasive implantation in the human or animal body is therefore provided. The valve stent comprises at least one tubular, mechanically compressible and deployable stent framework with an inflow opening and an outflow opening and one or more receiving frames for one or more valve leaflets integrated in the stent framework, wherein the receiving frames for the valve leaflets are aligned axially in the outer surface of the tubular stent framework and the total axial length H of the receiving frames is less than or equal to the distance from the inflow opening to the outflow opening of the valve stent, wherein an area of greater than or equal to 25% of the maximum length H of the receiving frame in the direction of the outflow opening is not arranged on the stent framework and is freely movable radially relative to the stent framework.

Surprisingly, it was found that the above-mentioned structure can be used to provide valve stents with valve leaflets that can be implanted minimally invasively and in which the valve tissue can withstand a significantly higher number of load changes without mechanical wear. This results in long-lasting valve prostheses that can be used with as little stress on the patient as possible and that can remain in the human or animal body for a very long time without losing their original functionality. A further advantage of this structure can be that the connection of the valve tissue to the stent is so advantageous that the valve tissue remains intact without the occurrence of tears in individual tissue components and therefore offers no further storage or deposition points for the body's own tissue or calcification. The reduced tendency for deposition can also increase the longevity of the valve stent. The structure of the stent for fixing the valve leaflets is also compatible with the conventional manufacturing methods of stents, so that the usual stent manufacturing methods can be used for the improved connection of the valve leaflets. The design of the stents also allows many different valve leaflets to be securely fixed, so that solutions adapted to the respective application situations are possible. Overall, this is more advantageous than the currently existing solutions, which either cannot be implanted minimally invasively or which show traces of mechanical stress and calcium deposits on the valve leaflet after periods of time that can still be improved.

The valve stent according to the invention is a valve stent for minimally invasive implantation in the human or animal body. A valve stent in the sense of the invention is a stent which additionally has the function of a valve. The valve function means that the stent is designed to open and close the stent passage for liquids. This valve function is carried out in the human body by heart or vein valves, for example. The valves are usually designed in the form of valve leaflets, which, depending on the flow through the valve, lie against one another with the leaflet edges and close the passage or, in an open configuration, allow the flow of liquids through the valve. The valve function is therefore carried out by movable parts which, as a function of the opening frequency, are exposed to very frequent mechanical load changes. The A stent as such is usually a tubular structure which is inserted into the human or animal body with its outer surface in contact with the vessel wall for mechanical stabilization. Stents are available in different designs and are offered, for example, in the form of coated or uncoated laser-cut metal tubes. Stents and in particular the valve stent that can be used according to the invention can be implanted minimally invasively. This means that for the valve stent to be inserted into the respective body, the stent can be mechanically compressed (compressible) and only unfolded again at the site of use. The compression and unfolding of the stent, including the valve tissue arranged on the stent, can therefore be carried out reversibly. The first step in stent implantation can be carried out, for example, by creating an external access to the patient. For this purpose, a cannula is inserted into a vessel that is close to the surface of the skin. Under X-ray control, a guide catheter is then advanced towards the site of use and the stent is placed at this point. The valve stent can therefore be mechanically reduced in size so that it can be inserted into the human or animal body through a catheter.

The valve stent comprises at least one tubular, mechanically compressible and deployable stent framework with an inflow opening and an outflow opening. The valve stent essentially has a cylindrical geometry and the internal volume of the stent can be reversibly reduced and increased. The compressibility of the stent framework is usually achieved by the fact that the stent is not made entirely of one material. The stent can be provided, for example, in the form of a wire mesh or a laser-cut bar framework. The stent cylinder has two round or oval openings on its front sides. Depending on the use of the stent in the fluid flow under in-vivo conditions, one opening of the stent is first flowed through with a volume of fluid. This first opening is the inflow opening. After flowing through the stent volume, the same volume of fluid reaches the second opening and leaves the stent from this second opening. This second opening is the outflow opening of the stent.

The valve framework contains one or more integrated mounting frames for one or more valve leaflets. To design a stent in the sense of a valve stent, the stent must contain additional devices that enable the connection of one or more valve leaflets. For this purpose, the valve stent according to the invention has one or more mounting frames in the valve framework, which interact with the material of the valve leaflets and fix it to the stent framework. The valve leaflet extends from the inside to the outside of the valve stent through the stent framework on the mounting frames. Essentially flat structures made of different materials can be used as valve leaflets. For example, the use of natural materials such as collagen from the pericardium of pigs or cattle is known. However, synthetic materials, such as plastic, can also be used. In addition, it is also possible for woven, knitted or crocheted materials in the form of textile leaflets to be used as valves. Textile ribbon fabrics can preferably be used for the valve stent according to the invention. The support frames for the valve leaflet(s) are integrated into the stent framework in that they are firmly connected to the framework of the stent. This can be done by firmly anchoring the support frames to the stent framework or, particularly preferably, by designing a part of the stent framework in such a way that it can serve as a support frame for the valve leaflets. In addition to fixing the valve leaflets in the support frames, the valve leaflets can of course also be arranged further along the stent framework, for example by means of sutures. The valve leaflets have a surface area that is mechanically fixed to the stent framework. Another part of the valve leaflets, however, is not fixed to the stent framework and is freely movable, so that this part can perform the function of opening and closing the valve. The stent framework can preferably have at least two, further preferably in particular three support frames for fastening the valves. This higher number of receiving frames can be particularly advantageous in cases where the valve is made up of several, for example three, individual valve parts, each of which is individually fixed to one another and to the stent framework. A receiving frame can, for example, be in the form of a narrow rectangle. The elongated connection points can then receive the valve leaflets in the form of more or less thin layers for fixing to or in the stent framework. To do this, the valve leaflets are guided from the inside through the receiving frames and fixed to one another and to the stent framework outside the stent framework. This connection can be used advantageously if several independently present valve leaflet parts are fixed to one another and to the stent framework.

The support frames for the valve leaflets are aligned axially in the outer surface of the tubular stent framework. The cylindrical design of the tubular stent framework results in a stent outer surface that corresponds to a cylinder surface. The support frames for the valves are located in this outer or cylindrical surface. This means in particular that the support frames do not protrude significantly inwards or outwards from the outer surface of the stent framework when not mechanically loaded. For example, it is possible for the support frames to extend a maximum of 5 mm, preferably a maximum of 2.5 mm and further preferably a maximum of 1 mm cyclically into the interior of the stent when the valve is closed and outwards, towards the vessel wall, when the valve is opened. The support frames extend parallel to the symmetry axis of the stent framework, i.e. are essentially aligned along the stent framework from the inflow opening to the outflow opening.

The total axial length H of the receiving frame is less than or equal to the distance from the inflow opening to the outflow opening of the valve stent. The axial length H of the receiving frame is the maximum extension of the receiving frame from the inflow opening to the outflow opening. Thus, according to the invention, the receiving frame does not take up the entire distance from the inflow opening to the outflow opening of the valve stent.

An area of greater than or equal to 25% of the maximum length H of the receiving frame in the direction of the outflow opening is not arranged on the stent framework and can move freely radially relative to the stent framework. Although the receiving frame is part of the stent framework and is arranged in the tubular outer surface of the stent framework, it is not mechanically connected to the stent framework evenly by struts over its axial extent. While part of the receiving frame is firmly connected to the stent framework, part of the receiving frame is not connected to the stent framework. This area not connected to the stent framework is located in the direction of the outflow opening of the stent and this part can move freely radially relative to the stent framework. According to the invention, at least a quarter of the maximum length H of the receiving frame is therefore not connected to the stent framework. In this case, the connection to the stent framework is made via the remaining maximum 75% of the support frame, which can be connected to the stent framework at certain points in the direction of the inflow opening or by means of transverse struts. The part not connected to the stent framework can therefore be almost freely movable relative to the stent framework. The free mobility arises in particular from the cyclic tensile load on the valve leaflet ends enclosed in the support frame when the valve is closed. The support frame can then be freely deflected radially inwards relative to the stent framework, in the direction of the main axis of the forces occurring.

In particular, this part of the support frame can be radially deflected in the direction of the stent interior and partially also in the direction of the vessel wall. This part can therefore flexibly absorb forces from the moving valve leaflets and pass them on to the stent framework at the connection points. This arrangement can mechanically compensate for the cyclical load peaks acting on the valve leaflets when the valve closes and protect the valve leaflet material in the area of the connection to the support frame and the stent framework. By flexibly cushioning the mechanical forces occurring at the valve supports, the overall load can be reduced and in particular the peak load on the valve leaflets can be reduced. This protects the connection point and significantly higher fatigue strength, i.e. a higher number of load cycles, of the valve leaflets can be achieved.

In a preferred embodiment of the valve stent, an area of greater than or equal to 50% of the length H of the support frame in the direction of the outflow opening cannot be arranged on the stent framework. For a particularly flexible and valve-friendly connection of the valve leaflets, free mobility of the upper 50% of the support frame has proven to be particularly suitable. In this area, the support frame lies in the outer surface of the stent framework, but is not connected to the stent framework by longitudinal struts oriented outflow or tangential or oblique struts. The forces that occur when the valve leaflets are opened and closed can be safely diverted to a large extent into the stent framework without causing too much force to act on the upper part of the connection of the valve leaflets to the support frame and thus also on the stent framework. A significant portion of the support frame can swing freely radially and thus help reduce the mechanical forces on the valve leaflets.

In a further preferred embodiment of the valve stent, the receiving frame can be at least partially coated with a plastic or a textile. Furthermore, it has proven to be particularly advantageous that the contact point between the valve leaflet and the stent is not designed as a metal contact. In particular, the connections of different valve leaflets materials to metal framework parts of the support frame or stent can contribute to the valve leaflet materials being subjected to high mechanical stress over time and giving way. By flexibly connecting the valve leaflets to the stent framework in conjunction with a textile or polymer buffer layer, a synergistic effect and thus longer service life of the valve stent under load can be achieved.

In a further preferred aspect of the valve stent, the support frame can be arranged in only one height position at the height of the stent frame center on the stent frame. In order to connect the valve leaflets to the stent frame as flexibly as possible, a design in which the support frame is fixed to the stent frame at only one point has proven to be effective. In this design, the upper part can swing freely against the stent frame in the direction of the outflow opening. The lower part of the valve leaflet ends can be fixed to the stent frame by sutures. The latter can in particular help to ensure that the cells that make up the stent frame open evenly when expanded, thus extending the longevity of the stent-valve combination.

According to a preferred characteristic of the valve stent, the support frame can be arranged in two height positions on the stent framework, with the first height position being at the height of the inflow opening and the second height position being at the height of the stent framework center. In order to safely and stably absorb the forces exerted on the valve leaflets, it has proven particularly advantageous that the support frame is connected to the stent framework at two points in particular. One of the points is located approximately in the direction of or near the inflow opening and the other connection point is approximately in the middle of the stent framework. The stent framework center in this context means the circumferential position on the cylinder, which is located on the circumference in the middle between the inflow and outflow opening.

A positional deviation of approximately 10% in both directions relative to the total stent height is still feasible. Any additional connections between the receiving frame and the stent framework can, for example, be located between the two height positions described.

In a further preferred embodiment of the valve stent, the receiving frame can have a reversible maximum vibration amplitude of greater than or equal to 0.01 and less than or equal to 0.2 relative to the inner diameter of the stent frame relative to the stent frame. The above-mentioned range of possible vibration amplitudes of the outflow-side edge of the receiving frame has proven to be particularly suitable for mechanically secure, but nevertheless material-friendly connection of the valve material to the stent frame. The maximum amplitudes of this edge are not too small, so that a relevant derivation of the forces from the valve leaflets to the stent frame is ensured. The amplitudes are not too large, however, so that reliable and reproducible mobility (opening and closing) of the valve leaflets is guaranteed. The maximum amplitude results from the maximum deflection of the uppermost tip of the receiving frame on the outflow side relative to the tubular surface of the stent frame. For a flap to function for a good five years, the support frame must be able to be moved 200 million times with this amplitude without breaking. The deflection of the support frame tip can be 0.5 mm/s, for example.

In a preferred aspect of the valve stent, the shape of the receiving frame can at least partially accommodate the symmetry of the stent framework at the same height position of the stent. In order to ensure particularly favorable dissipation of the forces exerted by the valve on the stent, it has proven to be particularly advantageous that the valve frame not only has a symmetry suitable for connecting the valve leaflets. A rectangular frame or a slot in the stent framework is generally suitable for simply accommodating the valve leaflet materials, which are usually flat. This symmetry of the reception and fixation of the valve leaflets can, however, advantageously be modified in such a way that a non-slot-shaped symmetry is formed in certain areas of the receiving frame. For example, the lower part of the receiving frame in the direction of the inflow opening can preferably have a diamond or honeycomb symmetry. This is particularly advantageous in cases in which the stent also has a diamond or honeycomb symmetry in the stent framework in these areas. In conjunction with additional seams made of non-absorbable suture material, preferably by connecting two adjacent cells (honeycombs) of the stent framework with the valve leaflet ends, this design can hold the valve leaflets securely on the one hand and ensure a particularly symmetrical introduction of force into the further stent framework for compression and re-expansion during implantation on the other. Examples of the design of this embodiment are given further down in the figures.

Furthermore, the invention relates to a valve prosthesis comprising a valve stent according to the invention and at least one valve leaflet. The advantages of the valve prosthesis according to the invention arise in particular from the interaction according to the invention and the connection of the valve leaflets to the stent framework to form a valve prosthesis. In this context, reference is made to the advantages of the valve stent in connection with the insertable valve leaflets. These advantages can be particularly high in cases in which the valve leaflets are not made from a single piece. The valve can consist of several valve leaflets, which can be fixed to one another on several support frames and, if necessary, also on the stent framework. By fixing the valve parts to one another, which mainly takes place on the support frames, a mechanically stable structure can be created that can withstand high forces and, in particular, frequent load cycles much better.

In a preferred embodiment of the valve prosthesis, the valve leaflet can comprise a ligamentous fabric. The inventive structure of a valve stent and valve leaflet made of a ligamentous fabric has proven to be particularly advantageous. Due to their mechanical structure, ligamentous fabrics are particularly suitable for connection to the stent framework using partially freely swinging support frames. This allows a large degree of freedom to be achieved for the physical properties of the ligamentous fabrics, which would not otherwise be possible due to the mechanical stress at the stent connection points. This makes it possible to develop other ligamentous fabric types and to significantly extend the fatigue strength under cyclic load for existing ligamentous fabric types.

In a further preferred embodiment of the valve prosthesis, the valve leaflet can be made of at least two band fabrics arranged next to one another and the valve stent can have at least two receiving frames, with two band fabric ends each being enclosed in a receiving frame and arranged against one another. Embodiments with several band fabrics arranged next to one another can have particularly favorable mechanical properties in connection with partially freely swinging receiving frames. The individual band fabrics can be securely fixed against one another on the receiving frames and the loads are transferred particularly well from the individual band fabrics in the valve area to the stent framework. Both can significantly improve the longevity of the prostheses under in-vivo conditions.

In a further preferred aspect of the valve prosthesis, the band tissues can be sewn together. In addition to a possible mechanical fixation against the stent framework, it has proven particularly advantageous that the band tissues are sewn against or to each other at their band tissue ends in the area of the receiving frame. Due to the mutual mechanical fixation, the individual band tissues can move at least partially independently of each other and only maintain mechanical cohesion in the area of the receiving frame. Suturing has proven advantageous in this context, as it is flexible and secure enough to absorb the mechanical forces that occur.

According to a preferred characteristic of the valve prosthesis, the band tissues can be glued to one another. In addition to a possible mechanical fixation against the stent framework, it has proven particularly advantageous that the band tissues are glued to one another or to one another at the respective band tissue ends in the area of the receiving frame. Due to the mutual chemical fixation, the individual band tissues can move at least partially independently of one another and only maintain cohesion in the area of the receiving frame. Gluing has proven advantageous in this context, as it is flexible and secure enough to absorb the mechanical forces that occur.

In a preferred aspect of the valve prosthesis, one or more axially extending plastic or metal reinforcements can be attached in or at the contact point of the ligamentous tissue outside the stent's internal volume. In order to flexibly adapt the stiffness of the contact surfaces of the individual valve leaflet components in the area of the receiving frame, it has proven advantageous to insert reinforcements in the form of rods or tubes adjacent to the outer surface of the stent framework. The rods or tubes can be attached between or at the fixation or direct contact point of different valve parts before the valve leaflets are fixed to one another. The reinforcements can have a homogeneous stiffness across the entire reinforcement. In principle, however, it is also possible for the reinforcements to have an inhomogeneous stiffness, with, for example, the upper part of the reinforcement being more elastic in the direction of the outlet opening than the lower part of the reinforcement. This allows the force absorption and force transmission to be adjusted particularly precisely, regardless of the valve leaflet material used.

Further advantages and advantageous embodiments of the inventive objects will be which is illustrated by the figures and explained in the examples below. It should be noted that the figures are only descriptive and are not intended to limit the invention in any way.

• 1 ein Stent-Gerüst für einen Klappen-Stent nach dem Stand der Technik;
• 2 schematisch eine erfindungsgemäße Ausführungsform eines Klappen-Stents im entfalteten Zustand in einem Ausschnitt;
• 3 schematisch eine erfindungsgemäße Ausführungsform eines Klappen-Stents im komprimierten Zustand in einem Ausschnitt;
• 4 schematisch eine erfindungsgemäße Ausführungsform eines Klappen-Stents im entfalteten Zustand in einem Ausschnitt;
• 5 schematisch eine erfindungsgemäße Ausführungsform eines Klappen-Stents im komprimierten Zustand in einem Ausschnitt.

The

• 1 a stent framework for a valve stent according to the state of the art;
• 2 schematically shows an embodiment of a valve stent according to the invention in the unfolded state in a detail;
• 3 schematically shows an embodiment of a valve stent according to the invention in the compressed state in a detail;
• 4 schematically shows an embodiment of a valve stent according to the invention in the unfolded state in a detail;
• 5 schematically shows an embodiment of a valve stent according to the invention in the compressed state in a detail.

The 1 shows a stent framework 2 for a valve stent according to the state of the art as in the US2020/0146815 disclosed. The stent framework 2 has the shape of a tube. The inflow opening 4 is located on the lower side of the stent framework 2 and the outflow opening 5 is located on the other, upper side. The stent framework 2 has a receiving frame 3 to which the valve leaflets (not shown) can be attached. The receiving frame 3 is connected to the stent framework 2 both in the direction of the inflow opening 4 and in the direction of the outflow opening 5.

The 2 shows schematically an embodiment of a valve stent 1 according to the invention in the unfolded state in a detail. For example, the stent framework can be unfolded in a vessel. A part of the stent framework 2 is shown. The stent framework 2 can be made from a metal tube by laser cutting, for example, so that a framework 2 made of metal bars results. Due to the structure, the stent framework 2 is reversibly compressible and unfoldable and can be implanted minimally invasively by means of a catheter in the human or animal body. The stent framework 2 has an inflow opening 4 and an outflow opening 5. The definition of the entry and exit results from the flow direction of the liquid that flows through the stent. To attach a valve leaflet 6, for example in the form of one or more valve leaflets 6 (here in the form of two valve leaflet ends arranged next to one another, for example) made of a fabric, the stent framework 2 has a receiving frame 3 (shown in dashed lines) to which parts of the valve leaflet 6 or the valve leaflets 6 can be attached. The stent framework 2 can have one, two, preferably three or more receiving frames 3. A part of the valve leaflet material can be guided to each of these receiving frames 3 from the inside of the stent through the receiving frame 3 to the outside of the stent and fixed to the stent framework 2 from the outside. If the valve is formed from several valve leaflets 6, the individual valve leaflet ends can be attached to the receiving frame 3 against one another and/or to the stent framework 2. The attachment can be made, for example, by sewing 7 or by gluing. The receiving frame 3 is axially aligned in the outer surface of the stent framework 2 and does not extend over the entire length from the inflow opening 4 to the outflow opening 5. In the axial alignment, the receiving frame 3 assumes a maximum length H. In the 2 it can be seen that the mounting frame 3 is not evenly arranged on the stent framework 2. The mounting frame 3 is only arranged in the lower area in the direction of the inflow opening 4 and in the middle area on the stent framework 2. The upper quarter of the mounting frame 3 in the direction of the outflow opening 5 is not arranged on the stent framework 2 and is more freely movable than the attached part. Due to the fact that the valve leaflet 6 is exposed to mechanical forces when opening and closing, if the valve leaflet 6 is rigidly connected to the stent framework 2, the valve leaflet material can tear if subjected to too much stress. The freely swinging connection of the valve leaflets 6 by the upper mounting frame 3 relative to the stent framework 2 partially compensates for the mechanical forces that occur and prevents mechanical failure of the valve leaflets 6 in the area of the connection to the stent framework 2. This can extend the fatigue strength of the valve stent 1 under load. Preferably, the valve material 6 can be made from several, for example three separate, band fabrics, the ends of which are fixed to three receiving frames 3 in pairs against each other and to the stent framework 2.

The 3 schematically shows an embodiment of a valve stent according to the invention in a compressed state in a detail. This figure shows a valve stent 1 with the same structure as the 2 In this figure, as in the 2 the stent framework 2, the inflow opening 4, the outflow opening 5, the receiving frame 3, the valve leaflet 6 are shown. The valve stent 1 can be placed in this compressed form in a catheter and introduced into the body through this in a minimally invasive manner. In addition, this figure shows that the valve leaflet 6 is attached to two further suture positions 7 to the stent framework 2.

The 4 shows schematically a further embodiment of a valve stent 1 according to the invention in the unfolded state in a detail. In this figure, as in the 2 the stent framework 2, the inflow opening 4, the outflow opening 5, the receiving frame 3 and the valve leaflets 6 are shown. The receiving frame 3 extends axially in the outer surface of the stent framework 2 and is only connected to the stent framework 2 at two positions. The receiving frame 3 does not extend to the inflow opening 4 of the stent framework 2. Just as in the 2 the receiving frame 3 is firmly connected to two points of the stent framework 2.

The 5 shows schematically an embodiment of a valve stent according to the invention in a compressed state in a detail. In this figure, as in the 4 the stent framework 2, the inflow opening 4, the outflow opening 5, the receiving frame 3 and the valve leaflets 6 are shown.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• WO 2010124219 A2 [0004]
• WO 2010020660 A1 [0005]
• EP 1804726 B1 [0006]
• US20200146815 [0034]

Claims (13)

Valve stent (1) for minimally invasive implantation in the human or animal body, comprising at least one tubular, mechanically compressible and deployable stent framework (2) with an inflow opening (4) and an outflow opening (5) and one or more receiving frames (3) integrated in the stent framework (2) for one or more valve leaflets, characterized in that the receiving frames (3) for the valve leaflets (6) are aligned axially in the lateral surface of the tubular stent framework (2) and the total axial length H of the receiving frames (3) is less than or equal to the distance from the inflow opening (4) to the outflow opening (5) of the valve stent (1), wherein an area of greater than or equal to 25% of the maximum length H of the receiving frame (3) in the direction of the outflow opening (5) is not arranged on the stent framework (2) and is free with respect to the stent framework (2) is radially movable. Valve stent after Claim 1 , wherein an area of greater than or equal to 50% of the length H of the receiving frame (3) in the direction of the outflow opening (5) is not arranged on the stent frame (2). Valve stent according to one of the preceding claims, wherein the receiving frame (3) is at least partially coated with a plastic or a textile. Valve stent after Claim 2 , wherein the receiving frame (3) is arranged in only one height position at the height of the stent frame center on the stent frame (2). Valve stent after Claim 2 , wherein the receiving frame (3) is arranged in two height positions on the stent framework (2), the first height position being at the height of the inflow opening (4) and the second height position being at the height of the stent framework center. Valve stent according to one of the preceding claims, wherein the receiving frame (3) has a reversible maximum vibration amplitude of greater than or equal to 0.01 and less than or equal to 0.2 relative to the inner diameter of the stent framework (2) relative to the stent framework (2). Valve stent according to one of the preceding claims, wherein the shape of the receiving frame (3) at least partially accommodates the symmetry of the stent framework (2) in the same height position of the valve stent (1). Valve prosthesis consisting of a valve stent (1) according to one of the Claims 1 until 7 and at least one valve leaflet (6). Valve prosthesis after Claim 8 , wherein the valve leaflet (6) comprises a ligamentous tissue. Valve prosthesis after Claim 9 , wherein the valve leaflet (6) is formed from at least two band fabrics arranged next to one another and the valve stent (1) has at least two receiving frames (3), wherein two band fabric ends are each enclosed on a receiving frame (3) and arranged against one another. Valve prosthesis after Claim 10 , with the band fabrics sewn together. Valve prosthesis after Claim 10 , whereby the band fabrics are glued together. Valve prosthesis according to one of the Claims 10 - 12 , wherein one or more axially extending plastic or metal reinforcements are arranged in or at the contact point of the band tissues outside the stent's inner volume.