Heart valve prosthesis

Description

[0001] The invention relates to a heart valve prosthesis which is attached to a support frame, in particular a mitral valve prosthesis which can be implanted transvenously in a minimally invasive manner by means of a catheter into the passage opening between the atrium and the main chamber.

[0002] The incidence of acquired heart valve defects increases with age. Aortic valve stenosis is now predominantly treated with transcatheter valve replacement (TAVI). TAVI valves are easily anchored due to the calcium deposits usually present in the native aortic valve.

[0003] In acquired mitral valve diseases, leaks (insufficiencies) play a major role. However, calcification of the mitral valve is usually insufficient to anchor an artificial heart valve. Furthermore, the mitral valve, which controls blood flow between the left atrium and the left ventricle, is difficult to access using minimally invasive techniques due to its location. Tight bends and curves must be negotiated, making catheter-based implantation very difficult. Furthermore, the function of the mitral valve is significantly more complex than that of the aortic valve.

[0004] Clinically significant mitral valve leakage (mitral valve regurgitation) affects approximately 8% of the population over 75 years of age in Western industrialized nations and, like aortic valve stenosis, is associated with a significantly increased mortality (Nkomo VT, Gardin JM, Skelton TN, Gottdiener JS, Scott CG, Enriquez-Sarano M. Burden of valvular heart diseases: a population-based study. Lancet 2006;368:1005-11). Nevertheless, only 2% of patients undergo surgical treatment (Head SJ, van Leeuwen WJ, Van Mieghem NM, Kappetein AP. Surgical or transcatheter mitral valve intervention: complex disease requires complex decisions. EuroIntervention 2014;9:1133-5). The high surgical risk and the lack of a simple and safe catheter-based valve replacement are likely the reasons for the inadequate treatment.

[0005] Currently, reparative procedures such as the MitraClip are predominantly used. A difficult learning curve and lack of effectiveness are among the main limitations. Transcatheter implantable mitral valves have been in development since 2012. Most systems attempt to transfer the technology (TAVI) that has proven successful in the aortic valve to the mitral valve, even though the two valves have completely different structures and functions. Other disadvantages include the fact that the systems either require a transapical access route (open surgery), require the initial insertion of an anchoring structure in the area of ​​the mitral valve annulus, lead to obstruction of the left ventricular outflow tract, have leaflets that are too thick (optimized for the aortic valve), or alter the natural anatomy due to non-physiological designs.All of these factors lead to increased complications during implantation and, even in cases of technical success, to an increased risk of thrombosis (Head SJ, van Leeuwen WJ, Van Mieghem NM, Kappetein AP. Surgical or transcatheter mitral valve intervention: complex disease requires complex decisions. EuroIntervention 2014;9:1133-5.). An 'ideal' system should be implantable via a transvenous / transseptal access route alone, have a slim design that fits into the natural anatomical features of the mitral valve annulus and support structures, and feature a slim, preferably bicuspid valve with a flow profile analogous to the natural mitral valve. The left ventricular outflow tract should be minimally compromised, which is a disadvantage of most currently proposed concepts.

[0006] Round, oval, or D-shaped cross-sections have been described in the literature. None of these cross-sections allows the stent to precisely adapt to the natural shape of the mitral valve orifice. For example, WO 2013 / 075215 describes a catheter-implantable mitral valve prosthesis consisting of a D-shaped stent-like support ring with attached leaflets. The support ring has a D-shaped cross-section. This results in an unphysiological alteration of the natural valve apparatus.

[0007] From US 2016 / 0331527 A1 a heart valve prosthesis is known in which the heart valves are attached to a wire-shaped tube with an inner and outer wall.

[0008] The cross-section of the tubular wire shape can be round, kidney-shaped or even in the shape of a large D.

[0009] EP 3 456 293 A1 describes an implantation system for a heart valve prosthesis. The heart valves are attached to an expandable, lattice-like anchor system that has a collar-shaped, extended radius on the atrium side.

[0010] US 2017 / 065409 A1 discloses a heart valve prosthesis for minimally invasive intravenous implantation.

[0011] The invention therefore aims to provide a heart valve, particularly a mitral valve, that can be easily administered or applied transvenously and is simple and easy to implant. Furthermore, the invention aims to provide a simple way to improve existing ventricular dilatation caused by overstretching of the valve filaments.

[0012] Furthermore, a very slim and flexible implantation set should preferably be provided for implanting the heart valve prosthesis, allowing it to be easily positioned and deployed, ensuring it is already in the correct anatomical alignment upon deployment from the catheter, and also capable of self-alignment. The heart valve prosthesis should ideally mimic the shape and function of the natural mitral valve and, in particular, modify the natural chords in such a way that negative remodeling of the left ventricle occurs. It should also preferably not lead to obstruction of the left ventricular outflow tract, and its flow profile, with its two leaflets, should correspond to the natural flow profile, thus avoiding thrombotic complications.

[0013] These objectives are achieved by the features defined in the claims.

[0014] According to the invention, it is proposed to attach a heart valve leaflet or a heart valve system to a stent-like holder, hereinafter also referred to as a stent, with a shape optimally adapted to the heart anatomy, which can be introduced into the location of the heart valve and deposited there via an implantation catheter optimized for this purpose. According to the invention, it has proven advantageous if the cylindrical stent is not completely circular, but has a cross-section that deviates from this in the direction of flow, having the shape of a kidney, bean, or banana. The cross-section has a maximum length a, a maximum width b, and a minimum width c. Here, a is greater than b and b is greater than c. The size a corresponds to the diameter of a circle that surrounds the heart valve.

[0015] The kidney shape, in particular the outer curve, can be conveniently described by a circumference similar to a circle around the end point of the small width c. In the simplest case, the curve represents a circle with a center point that lies inside the kidney shape at the end of the middle small width c, i.e. in the depth of the kidney-shaped indentation. This center point can fluctuate with respect to the width a by + / - 20%, in particular by + / - 10%, with + / - 5% being preferred. This can result in an oval or elliptical cross-section. If this is the case, the length a is divided unequally and the two parts are no longer the same length.

[0016] The kidney-shaped cross-section preferred according to the invention has a maximum length a, typically 20-45 mm, in particular 25-40 mm, and preferably 28-38 mm. The large width b is typically 10-30 mm, with 13-28 mm to 15-25 mm being preferred. The central small width c is typically 5-25 mm, with 7-23 mm or 9-20 mm being preferred. In this case, a is greater than b, and b is always greater than c.

[0017] According to the invention, a cross-section is preferred which has the shape of two opposing D letters, in which one D is arranged laterally inverted, the straight vertical lines of the two Ds lying next to one another and the cross-sectional edge is formed by different curvatures or curves of the D. In this shape, the length c defined in the previously described cross-sectional shapes is omitted and is replaced by the sum d of the respective maximum distances (maximum belly curvature) of the two opposing D letters, which consists of the sum of the large distance (maximum belly curvature) d 1 and the small distance (maximum curvature) d 2, each measured from the imaginary straight vertical line of the D. In this case, a is greater than d. This distance d 1 (large curvature or large arc) then corresponds to the length b of the previously described cross-sectional shapes.At the point where the curved line of the two Ds touches, the curves merge without a kink. In a special design, this area can even be briefly straight for a short length.

[0018] The dimensions described above apply to the cross-sectional lengths a and d 1 . For the smaller curvature of the smaller D, the maximum distance d 2 from the imaginary upstroke or straight line of the letter D is at least 0.5 mm, preferably at least 0.75 mm, with at least 1 mm, in particular at least 2.5 mm or 3.0 mm being particularly preferred. In an expedient embodiment, the curvature is at least 7.5 mm. The ratio of the two heights from the imaginary straight d-line between the large d 1 (smaller radius) and the small d 2 (larger radius), i.e. d 1 to d 2, is at most 20:1, in particular at least 2:1, with ratios of at most 5:1, at most 10:1 and in particular at most 15:1 being preferred. The height of the respective imaginary D-back line a is 15 mm to 50 mm, in particular 20 to 45 mm, depending on the desired heart valve size.

[0019] In a further preferred embodiment, the stent has a smaller web width on the side of the smaller curvature with the distance d 2 (large radius) than on the side of the larger curvature (with the distance d 1 ). The web side on the larger curvature is typically 0.3 mm to 0.6 mm, but preferably at least 0.35 mm and at most 0.4 mm or 0.55 mm. This web side is designed to be thinner on the side of the flatter curvature (large radius) and is at most 55% of the web width on the side with the larger curvature. The minimum web width in a preferred embodiment is 10%, in particular 20 or 25% of the web width on the more strongly curved side (in Fig. 8 shown on the right).

[0020] With the prosthesis according to the invention, particularly due to the different thicknesses of the stent bridges, it is possible for the implanted heart valve prosthesis, especially in its stent area, to adapt to the beating heart. It has been shown that the design with the thinner or narrower bridge width allows the mobile heart muscle to move the stent prosthesis during contraction and does not remain relatively rigid due to the strong counterpressure of the stent. This allows the stent to adapt to the natural movement of the heart muscle and to securely seal the opening even in its mobile form.

[0021] Preferably, the cross-sectional area of ​​the stent-like mesh initially decreases in the direction of flow from the atrium and then increases again after passing through the opening to the main chamber, creating a possibly slight waist-like constriction that is encompassed by the heart muscle. In this way, the stent-like mesh or framework of the prosthesis sits firmly in the heart's opening.

[0022] The one like in Fig. 6 The cross-section shown is preferably a cylinder constricted on the atrial side. It is represented by two different truncated cones. The height of the upper truncated cone is between 51 and 80%, and the lower truncated cone is between 49 and 20%, based on the total length of the stent.

[0023] The stent-like valve leaflet holder according to the invention has a shape that adapts to the natural shape of the mitral valve, which deviates significantly from a circular shape and forms a bean-shaped, kidney-shaped or banana-shaped cross-section, which can be symmetrical or asymmetrical in all cross-sectional planes (relative to the flow direction).

[0024] In a preferred embodiment, the stent has a larger dimension or surface area in the area of ​​the passage opening between the antechamber and the main chamber than the natural surroundings, whereby dilated valve threads are re-tensioned if necessary.

[0025] In a further preferred embodiment, the stent-like mesh or holding device has small, outwardly directed holding elements or barbs on the side facing the atrium and / or the side facing the ventricle. This makes it possible to firmly anchor the stent-like holding element to the valve opening.

[0026] Fig. 1 shows a stent with circumferential atraumatic retaining elements. The number of retaining elements ranges from 2 to 15, typically at least four, with at least 8 being preferred.

[0027] The valve leaflets are attached to the holding element or the stent-like holding device.

[0028] In the area of ​​the natural posterior leaflet, the stent or the heart valve support or framework shows a curved course with different curve radii (PML; P1 section to the anterior commissure, P2 middle section of the PML and P3 segment to the posterior commissure) ( Figur 7 ), whereby the curve radii can differ from one another; in particular, there is no complete mirror symmetry between the P1 and P3 segments. The curvature has the largest radius in the P2 segment region, while P1 and P3 have a smaller radius. According to the invention, the radius of P1 is smaller than P3 or of P1 is larger than P3. Identical curve radii in the P1 and P3 regions are also possible.

[0029] In a further preferred embodiment, the shape of the heart valve holder in the region of the anterior leaflet (AML) is adapted to the natural anatomy of the mitral valve.

[0030] Relative to the imaginary curve curved towards the native PML, which extends between the commissures of the natural mitral valve, the shape of the stent or heart valve support or scaffold in the commissure-proximal regions of the A1 and A3 segments is a curve directed outwards towards the LVOT, which then crosses the imaginary curve between the commissures inwards towards the native PML in the middle section of the A1 and A3 segments or at the respective transition to the A2 segment and continues this in an arcuate curve shape. The respective curve radii are typically not symmetrical between the A1 and A3 segments, and the curve shape within the A2 segment is also not mirror-symmetrical. The respective radii can be the same, larger, or smaller.

[0031] The physiological function of the mitral valve also includes movement in the third dimension depending on the cardiac cycle. The mitral valve presented here allows for deformability during the cardiac cycle, both at the level of the valve annulus and toward the left atrium and left ventricle. Adapting to the natural anatomy of the native mitral valve also enables a better fit and retention of the prosthesis. Furthermore, this shape has been shown to be self-centering.

[0032] With the prosthesis according to the invention, the valve's natural support structure remains intact, as the prosthesis is attached to the natural valve opening without significantly altering the other anatomical features. Furthermore, it has proven particularly advantageous to select a stent to which the actual valve leaflets are attached that is larger than the existing diameter of the opening. This makes it possible to re-tension dilated or overstretched valve sutures that hold the actual valves.

[0033] This also leads to increased pretension of the natural tendon threads and their associated papillary muscles, resulting in, in the best case, negative remodeling of the left ventricle. This is facilitated by the fact that the inventive shape and function of the valve prosthesis mimics the natural mitral valve, thus leading to uniformly improved pretension of the natural tendon threads across all planes.

[0034] The positioning, which is adapted to the natural anatomy, prevents obstruction of the left ventricular outflow tract in all cases, even in cases where the anatomy is unfavorable.

[0035] The valve leaflets are typically bicuspid, but valve prostheses with 3 or even 4 individual leaflets can also be used.

[0036] Retaining sutures integrated into and attached to the valve framework mimic the natural tendon sutures and prevent the leaflets from piercing the atrium during ventricular contraction. The number of retaining sutures per leaflet ranges from 1 to 15, typically at least three, with at least four being preferred. The maximum number of retaining sutures is 15, with a maximum of 9 or 7 being preferred.

[0037] The valve leaflets form an adaptation line in their contact surface, along which the leaflets rest against each other and prevent / close backflow. The adaptation line of the leaflets is typically based on the shape of the stent, but can also deviate from this. Typically, the adaptation line runs from the location of the natural commissure between A1 / P1 to the location of the natural commissure between A3 / P3, but can also be shifted by up to 5 mm, in particular 4 mm or 3 mm, in anterior or posterior direction. The curvature of the adaptation line follows the adaptation line of the natural valve, but can also be shifted by up to 5 mm, in particular 4 mm or 3 mm, in anterior or posterior direction. In a preferred embodiment, the leaflets on the atrium side are continued on the inside of the stent towards the ventricle for lateral sealing, as is the case, for example, in Figur 6 b is shown.

[0038] To insert such a heart valve system, it is first necessary to load it into an application set / catheter system, which is introduced transvenously, either via an anatomically caudal vein (typically percutaneously the femoral vein or surgically exposed veins in the pelvis, but not limited to these) or a cranially located vein (typically percutaneously or surgically a jugular vein or the subclavian or axillary vein, but not limited to these).The application set has the necessary dimensions and, above all, flexibility to follow the path to the mitral valve via a transseptal access route from the right to the left atrium and further towards the left ventricle through the natural mitral valve via a previously placed guide wire, even if the distance between the transseptal puncture level and the mitral valve level is typically no more than 4 cm, typically no more than 3 cm, preferably no more than 2 cm.

[0039] To position the prosthesis according to the invention, a so-called steerable catheter is expediently used. The distal end of such a catheter can be bent into a curve. This curve then forms a plane with the similarly curved supply vein. Looking at the cross-section of the vein, the outer side of the curve, i.e., the side facing the other, right chamber of the heart, describes a 12:00 o'clock position, and the point on the inner side of the curve describes a 6:00 o'clock position.

[0040] The design of the application set is slim and flexible, with the distal section being controllable in its curvature. The catheter shaft is a maximum of 14 French, typically between 8 and 12 French. The distal part of the application set carries the stent with the attached valve, which is only a few millimeters larger than the catheter shaft, typically 2 mm, but also between 0.5 and 4 mm. mm. The curvature of the catheter shaft or the distal portion of the delivery system is controllable, typically within a range of -20 to approximately 210 degrees. The delivery system allows the valve to be loaded in a predefined orientation, delivered to the target site, and released in a defined anatomical position.

[0041] In a preferred embodiment, the stent of the prosthesis according to the invention has a positioning aid, the application of which can only be loaded at one designated location. Only at this location does the positioning aid fit into the instrument, like a key into a keyhole. It has proven expedient to position the positioning aid at the 6-8 o'clock position, preferably at the 6.5-7.5 o'clock position, as described above. Furthermore, it has also proven expedient to place radiopaque and / or ultrasound-visible markings on the stent, which allow the physician using the device to monitor the position of the stent and thus the valve leaflets.

[0042] The invention will be explained by way of example using the following figures.

[0043] They show: Fig. 1 shows a stent-like heart valve holder or heart valve holding element 1.0. The stent-like holder or grid contains a fixing element 1.1 for fixing the stent-like element in the heart. Such a fixing element 1.1 is preferably designed in the form of an eyelet. The eyelet itself is bent outwards from the central axis of the stent-like, grid-shaped element (direction of blood flow) so that it anchors itself in the heart muscle. In addition, it has a constriction 1.2 around its cylindrical outer surface. Along this constriction 1.2, the stent or stent-like grid has a smaller circumference than at its two distal ends. At its other distal end, opposite the fixed elements, the grid of the holder has holding eyelets 1.3 for fastening the holder to a location provided for this purpose in the application set or catheter, wherein at least one holding element is provided with a marker 1.4 to check the position of a valve support or stent opened in the heart. Such markers are preferably radiopaque. In principle, it is also possible to provide such markers using materials that are particularly well visible on ultrasound.

[0044] Fig. 2 shows a front view or cross section of the stent-like holding grid or element of Figur 1 As can be seen, such a stent is preferably not completely round, but is flattened on at least one side. This allows it to adapt to the natural shape of the opening in the heart between the atrium and the ventricle.

[0045] Fig. 1 and 2show the basic structure of the valve's stent framework. The shape is adapted to the natural shape of the mitral valve. One or more positioning eyelets (1.4) for loading the prosthesis are located, preferably on the atrium side, which only have a predefined position in the holding system of the application set / catheter system ( Fig. 3 , Fig. 4 ) and serve to retract the heart valve back into the delivery set until shortly before deployment, should this be necessary for retrieval or repositioning, or if final deployment is not yet desired. The positioning eyelet is held firmly in place at one point on the catheter.

[0046] Furthermore, at the level of the native mitral annulus, there is a constriction (1.2) of the stent-shaped heart valve holder, which allows a defined height and at the same time serves to ensure stability in the anatomically correct position.

[0047] On the ventricular side, there are round shapes or fixation elements of the stent (1.1), which also serve to ensure the correct anatomical height and stability of the system.

[0048] Fig. 3 shows a catheter system for placing the inventive heart valve with a loaded stent / implant 3.3, which is held in the catheter system 3.1 by the stent holder 3.2. The catheter system is closed at the front by a flexible tip 3.4, guided by a guidewire 3.5.

[0049] The catheter system 3.1 and the holder for the stent-like support frame 3.2 are therefore preferably constructed such that, when viewed from above, a recess for receiving the centering element or the centering eyelet 2.1 is located at the "7 o'clock" position of the catheter tip, so that the stent-like support element can only be loaded into the catheter in this position. The centering element 2.1 is located on the stent / implant 3.3. The centering element has two specific functions: first, to load the stent exclusively and only in the correct position, and second, to fix the stent-like holder or the entire implant. The holding eyelets 1.3 and 1.4 on the stent-like support frame 1.0 also have the task of fixing the prosthesis to the holder 3.2 so that the stent can be released or positioned evenly and without "jumping." The holding eyelets 1.3 and 1.43 are additionally equipped with markers, the markers show the position and location of the stent after positioning, as well as the control of the opened stent / implant.

[0050] The defined anatomical position largely corresponds to the natural shape of the mitral valve. During deployment, the valve realigns itself again to the natural anatomy in a range of between -30 and +30 degrees, typically between 15 and 25 degrees, and particularly up to 20 + / - 3 degrees of rotation.

[0051] The orientation of the catheter system relative to the native mitral valve is defined by the plane defined by the curved catheter system perpendicular to the atrial septum, which also intersects the valve plane perpendicularly. This virtual plane intersects an imaginary clock lying on the mitral valve at 12 and 6 o'clock. The position of the stent with the valve is rotated 30 degrees to the right in the catheter, so that the position marker points to the 7 o'clock position ( Fig. 2 ).

[0052] Fig. 4 shows a partially deployed stent / implant 3.3, with the positioning eyelets 2.2 indicating the position or location of the stent / implant during fluoroscopy. The positioning eyelets indicate the correct position of the stent / implant. Furthermore, the positioning eyelets also serve as a holding eyelet, i.e., the holding eyelet acts as a stop on the old valve. The fixation eyelets 1.1 additionally secure the stent / implant in the deployed position.

[0053] The horizontal cross-section of the valve holder 1.0 according to the invention is preferably shaped like a bean or kidney. Due to this shape and the loaded "7 o'clock" position in the catheter system 3.1, the valve holder (stent / implant) 1.0 already has the predetermined optimal direction regarding position and location in the heart upon discharge from the catheter system 3.1.

[0054] Fig. 2 shows the top view of the stent / implant 3.3, here the centering eyelet 2.1 is clearly visible at the "7 o'clock" position.

[0055] Thanks to the inventive measures of predefined loading in the application set, its controllable and defined bending behavior and the alignment of the valve plane, as well as the self-aligning properties of the valve (rotation and height), implantation is possible using standard imaging techniques and with the usual imaging expertise of the examiner. Conventional X-ray fluoroscopy with continuous flow angiography or right ventricular angiography or venocardiography, as well as transthoracic and transesophageal echocardiography in two-dimensional or multi-dimensional resolution, is sufficient for imaging. Alternatively, intracardiac ultrasound (ICE) can also be used.

[0056] It has also proven useful to add different positioning aids. It has also proven advantageous to design these positioning aids differently, so that during implantation, the attending physician can always see how to safely and easily rotate the stent-like holder into the correct position for implantation.

[0057] Such positioning aids are, for example, radiopaque. In principle, they can also be used with other materials, such as those that are clearly visible in an ultrasound.

[0058] Fig. 5 shows a stent-like holding element in the shape of a bean, kidney or banana in a top view in the direction of blood flow as well as in a side view.

[0059] This side view shows a stent-like retaining element featuring two opposing cones, each with a constriction 1.2 at its narrowest point. This constriction serves to center and position the deployed stent within the valve plane. Furthermore, the constriction also locks the stent / implant 3.3 in place, thus securing it upwards and downwards.

[0060] Fig. 6 a shows a section through the mitral valve prosthesis 1.0 according to the invention with leaflets 6.1 and the tendons or leaflet threads 6.2 holding them and the constriction 1.2.

[0061] The adaptation line between A1 / P1 to the site of the natural commissure between A3 / P3 is the Fig. 6 c can be found.

[0062] Fig. 7 shows segmental anatomy of a natural mitral valve with location of the anterior A1 - A3 commissure and the posterior P1 P3 commissure.

[0063] Figur 8 shows a particularly preferred embodiment of the web of the heart valve prosthesis according to the invention. As can be seen therefrom, the cross section is formed by two shapes lying opposite one another on their vertical side, each representing a capital D. The larger part of the cross section with the capital D shape has a maximum distance from the imaginary straight D line d 1 . The curve of the (smaller left) D has a maximum distance d 2 from the imaginary straight line. The total width of the stent (from the maximum D curvature on the left side to the maximum D curvature on the right side) is therefore d 1 + d 2 . The maximum length of the D (corresponds to the imaginary vertical D line of the letter D) is represented by the length a. Figur 8b shows the preferred shape of the stent cross-section of the heart valve prosthesis according to the invention. Fig. 8 The form shown has a smaller bridge width, especially on its left side. List of reference symbols

[0064] 1.0 Heart valve holder 1.1 Fixing element 1.2 Constriction 1.3 Holding eyelet 1.4 Positioning eyelet 2.1 Centering eyelet 2.2 Positioning eyelets 3.1 Catheter system 3.2 Fixing holder 3.3 Implant (stent mesh and leaflet) 3.4 Catheter tip 3.5 Guide wire 6.1 Mitral valve leaflet 6.2 Mitral valve suture

Claims

1. A heart valve prosthesis for minimally invasive intravenous implantation, comprising a biocompatible flexible material having at least one movable valve leaf for opening and closing a passage opening between the atrium and the ventricle of the heart, which opening is fastened to a retaining member of a stent-like cylindrical mesh made of a radially expandable material, wherein the stent-like mesh has a cross-section in the form of a double D contacting at its rear side when viewed from the valve apparatus, characterized in that the cross-section formed by a double D is such that one of the Ds comes to lie laterally opposite the straight line of the back of the other D with its imaginary straight back line, wherein one of the two Ds has a greater curvature than the other D.

2. The heart valve prosthesis of claim 1, characterized in that the stent-like mesh on the side of the D with the smaller curvature has webs with a smaller web width than the webs on the stent side with the greater curvature.

3. The heart valve prosthesis of claim 1, characterized in that the ratio of the maximum distance of the greater curvature from the imaginary straight back line of the D to the corresponding maximum distance of the other D with the smaller curvature is 20:1 mm to 2:1 mm.

4. The heart valve prosthesis of claim 1, characterized in that the stent-like mesh comprises circumferential atraumatic retaining members for fixing to the damaged mitral valve.

5. The heart valve prosthesis of any one of the preceding claims, characterized in that the stent-like mesh has a positioning aid.

6. The heart valve prosthesis of any one of the preceding claims, characterized in that the stent-like mesh has a height of 20-50 mm.

7. The heart valve prosthesis of any one of the preceding claims, characterized in that the compatible material is a biological tissue selected from autograft, human graft, xenograft, or collagen cultures.

8. The heart valve prosthesis of any one of the preceding claims, characterized in that the length of the mesh is selected such that it projects at least 2 mm into the atrium.

9. The heart valve prosthesis of any one of the preceding claims, characterized in that the stent-like mesh material is nitinol.

10. The heart valve prosthesis of any one of the preceding claims, characterized in that the stent-like mesh has outwardly directed retaining members.

11. The heart valve prosthesis of any one of the preceding claims, characterized in that the stent-like mesh has a cross-section which decreases from the atrium to the passage opening and increases again in the flow direction after the passage opening.

12. The heart valve prosthesis of any one of the preceding claims, characterized in that the prosthesis comprises two mitral-shaped bicuspid flaps.

13. A kit of parts comprising a prosthetic heart valve of any one of claims 1 - 12 and an implantation device for implanting such heart valve prostheses, characterized in that the device comprises a controllable catheter and has an element exclusively for accommodation as a positioning aid.

14. The kit of parts of claim 13, characterized in that the positioning aid is arranged in the "7 o'clock" position.