Stent for the positioning and anchoring of a valvular prosthesis in an implantation site in the heart of a patient

[0001] The invention relates to a stent for positioning and anchoring a valve prosthesis at an implantation site in a patient's heart. In particular, the invention relates to an expandable stent for an endoprosthesis used to treat cardiac valve stenosis (stenosis) and / or cardiac valve failure.

[0002] Document DE 20 2007 005 491 U1 relates to an expandable stent comprising a plurality of positioning arches as well as a plurality of retaining arches. Retaining arches are provided with slotted holes through which the cardiac valve prosthesis can be attached to the stent. The conventional stent known from this prior art is further equipped with a plurality of connecting webs for joining positioning arches to holding arches.

[0003] Document WO 2008/035337 A relates to a prosthesis for implantation in a native crescent valve of a native valve assembly. The prosthesis comprises a distal attachment, configured for placement in the distal artery, and shaped to define exactly three proximal coupling arms that are configured to be positioned at least partially in the respective crescent sinus and, in combination, for use in tissue, which determines the crescent sinus, the first axial force directed toward the ventricle of the heart. The prosthesis additionally comprises a proximal attachment member connected to the distal attachment member, a proximal attachment member configured to place at least partially on the ventricular side of the native crescent valve, and for application to the ventricular side of the native valve assembly, a second axial force toward the distal artery. , such that the application of the first and second forces engages the prosthesis with the native valve assembly.

[0004] The expression "stenosis (stenosis) of the heart valve and / or heart valve failure" is intended to include a functional defect in one or more heart valves that is either genetic or has developed. This type of heart defect can also affect each of the four heart valves, although it often affects the left ventricular valves (aortic valve and mitral valve) much more than the right ventricle (pulmonary and tricuspid valve). A functional defect may result in narrowing (stenosis), inability to close (failure) or a combination of both (combined vitium). The invention relates to a expandable stent for introducing a heart valve stent into a patient's body for the treatment of such a heart valve defect.

[0005] In the current treatment of severe cardiac valve stenosis and / or cardiac valve insufficiency, the narrowed or diseased heart valve is replaced by a prosthetic valve. For this, biological and mechanical valve models are used, which are usually surgically sewn into the heart valve bed through the chest opening after removal of the diseased heart valve. This operation requires the use of a cardiopulmonary device to maintain the patient's circulation, during the procedure and cardiac arrest is induced during implantation of the prosthesis. It is a risky surgical procedure related to the risks to the patient as well as long postoperative treatment and recovery phase. Such surgery may often not be considered with justified risk in the case of polypatic patients.

[0006] Recently, minimally invasive forms of treatment have been developed that are characterized by enabling the procedure under local anesthesia. One approach involves the use of a catheter system to implant a self-evolving stent to which a foldable valve prosthesis is attached. This self-evolving endoprosthesis can be introduced through a catheter system into the implant site in the heart through an artery or inguinal vein. After reaching the implantation site, the stent can then be developed.

[0007] In this regard, it is known that a stent may comprise, for example, a plurality of self-evolving longitudinal stent segments, segments articulated with respect to each other. To anchor the stent securely in a suitable blood vessel near the heart, anchor burrs are often used to engage the vessel wall.

[0008] A stent Expandable for fixing and anchoring a valve prosthesis is known from printed publication DE 10 010 074 A1, wherein the valve is essentially formed of wire-shaped segments joined together. DE 10 010 074 A1 proposes a stent for fixing and anchoring a valve prosthesis, a stent with various arcuate elements that assume the function of securing and supporting the valve prosthesis at the implantation site. In particular, three identically configured positioning arches are used, respectively 120 ° apart. These positioning arches are connected to each other by means of fixed body joints. In addition to the positioning arches, the complementary curved attachment arches are used to anchor the endoprosthesis by pressing radially on the vessel wall after unfolding the stent.

[0009] However, by using the solutions described above, there is a risk of inaccurate or incorrect implantation of the valve prosthesis. Put differently, there is a need for accurate positioning and longitudinal alignment of the implanted valve prosthesis. This is especially possible when using high skills on the part of the attending physician or cardiologist - if any - to position the stent accurately sufficiently, both transversely and longitudinally, to ensure that the combined valve prosthesis is located in the right area of ​​the diseased heart valve the patient. [0010] Among other things, inaccurate implantation of a sub-optimally positioned valve prosthesis can lead to valve leakage or failure, resulting in significant ventricular stress. For example, if a valvular prosthesis is implanted too far above the plane of the native cardiac valve, this can lead to closure and blockage of coronary artery (coronary artery inlet) orifices, and thus fatal coronary ischemia and myocardial infarction.

[0011] Therefore, for optimal treatment of the narrowed heart valve or heart valve failure, it is necessary to place the stent to which the valve prosthesis is attached as accurately as possible at the site of implantation of the heart valve to be treated.

[0012] Endoprosthesis for the treatment of aortic valve insufficiency is known from DE 20 2007 005 491 U1. The endoprosthesis includes a valve prosthesis and a stent for positioning and anchoring the valve prosthesis at the implantation site in the patient's heart. This endoprosthesis uses a stent with several (many, usually three, but two in the case of a mitral valve) positioning arches. In the implanted stent condition, these positioning arches extend radially and serve to attach in the pockets of the native (diseased) heart valve to be treated. The valve prosthesis attached to the stent can then automatically position itself in the plane of the heart valve. The fastening arches adhere to the aortic vascular wall in the implanted state of the endoprosthesis, forming a force-fit connection and are used to anchor the endoprosthesis.

[0013] While the positioning arches allow the stent of this endoprosthesis to be optimally positioned at the implant site in the patient's heart, it cannot be guaranteed that the valve prosthesis attached to the proximal end of the stent is also correctly positioned in the plane of the heart valve. In particular, significant forces act on the valve prosthesis during the filling phase of the heart cycle (diastole), which can lead to the valve prosthesis moving longitudinally relative to the stent. Due to this longitudinal displacement of the implanted valve prosthesis that occurs in the heart and blood vessels, particularly due to peristaltic movement of the heart, the implanted valve prosthesis may not be able to provide a secure seal.

[0014] Furthermore, there is the danger that due to the longitudinal displacement of the valve prosthesis relative to the stent, occurring in peristaltic movement, the threads or fibers used to attach the valve prosthesis to the stent may rub against the stent. It cannot therefore be ruled out that the fastening threads may fray over time and thus lose their fastening function. This could lead to at least partial separation of the valve prosthesis from the stent, which in turn may lead to leakage, incorrect positioning or even complete detachment of the valve prosthesis.

[0015] Based on the problems described above, certain embodiments of the invention address the issue of providing a self-evolving endoprosthesis for treating a narrowed cardiac valve or heart valve failure that realizes the optimal positioning and anchoring accuracy of an implantable valve to be implanted. In addition, treatment of narrowed heart valve or heart failure should be carried out by a simple procedure allowing routine treatment of narrowed heart valve or heart failure without much stress for the patient.

[0016] A further task of some embodiments of the invention is to determine an endoprosthesis for treating a constricted heart valve or heart valve failure, wherein the endoprosthesis can be safely anchored at the implantation site in the patient's heart. In addition, some embodiments of the invention generally also address the issue of preventing the implanted valve prosthesis from moving from its ideal implantation site, despite the forces acting on the endoprosthesis during the filling phase of the heart cycle. [0017] According to one example, a Expandable stent is proposed according to some embodiments of the invention, a stent comprising at least one attachment portion by which the valve prosthesis is connected to the stent. In addition, the stent includes positioning arches and retaining arches. At least one positioning arch of the stent is connected to the at least one retaining arch of the stent by means of a first connecting web. In addition, the stent includes at least one additional arch that connects the arms of the respective retaining arches to each other.

[0018] The at least one attachment portion extends along the longitudinal axis of the stent and comprises a plurality of attachment holes arranged in the longitudinal direction at separate locations along the length of the at least one attachment portion. Thread or thin wire may be passed through each attachment hole for attaching the valve prosthesis to the stent. The advantage of this feature is that the longitudinal displacement of the valves relative to the stent is substantially minimized when the implanted prosthesis is not excessively disturbed or weakened due to peristaltic movement of the heart.

[0019] In addition to the attachment holes, the attachment portion may include one or more notches to aid the deposition and retention of the seam material. The notches also help to evenly attach the prosthesis to the stent and, like the mounting holes, minimize the longitudinal displacement of the prosthesis.

[0020] Depending on and between the pair of fastening parts, there is a fastening arch over which valve tissue is laid. The fastening arch is located inside the perimeter of the stent. Therefore, the denture tissue is separated and kept away from the positioning and holding arches, thereby reducing the probability of these arches rubbing the tissue, which in turn can lead to damage and weakening of the prosthesis. The fastening arch is used to anchor the lower edge of the valve prosthesis and to tension the material making the prosthesis effective as a valve. Due to the presence of the fastening part and the fastening arches, the denture is fully supported and anchored within the stent. The combination of these two attachment mechanisms also ensures safety in the event of failure of one attachment mechanism. This is particularly important when sewing because a poorly sewn denture will not be as effective as it should be because of additional stresses and deformations transferred to the prosthesis through the sutures. Thus, the arches allow the prosthesis to be attached in such a way that it is not based solely on the sutures.

[0021] In the implanted configuration, the at least one positioning arch of the stent extends from the circumference of the stent in a substantially radial direction. These positioning arches are intended for attachment in the pockets of the native (diseased) heart valve to be replaced, which in turn allows accurate positioning of the stent. In addition, after implantation, the positioning arch settles between the vascular wall and the native heart valve leaflet. The positioning arch then cooperates with the respective holding arch, which results in trimming the native leaflet between the two arches. Thus, the positioning and holding arches together hold the stent in position and substantially eliminate axial rotation of the stent.

[0022] In a preferred embodiment, the positioning arch may be shaped to a substantially convex shape. In other words, the end of the arch that is located in the native valve leaflet may be curved inwardly in the stent, or in the direction of the longitudinal axis of the stent. Thus, the shape of each positioning arc provides additional shear force to the native valve flap.

[0023] At least one supporting arch is connected to the positioning arch via a connecting web. The holding arch extends radially in the implanted state of the stent so that at least one holding arch is pressed against the wall of the blood vessel in which the stent is arranged with a radially acting tension force. In place, the ends of each retaining arch also fit below the aortic annulus, providing additional means for locating and anchoring the stent. In addition to at least one retaining arch, some embodiments of the invention provide a stent further comprising at least one additional arch that connects the respective arms of the arch to at least one retaining arch connected to at least one positioning arch. As with at least one retaining arch, the at least one auxiliary arch also extends radially in the expanded state of the stent so that at least one auxiliary arch also presses against the wall of the blood vessel in which the stent is arranged with a radially acting tension force.

[0024] The stent may further include radial arches sandwiched between each positioning arc, with each radial arc extending upward towards the distal end of the stent. Radial arches provide additional means by which the stent can be held in the catheter before and during implantation, and provide means by which the stent can be recovered after implantation. Arches also add radial strength to the distal end of the stent.

[0025] In at least one stent attachment portion, by means of which the valve prosthesis can be attached to the stent, a plurality of attachment holes and, optionally, one or more notches are provided. Such attachment holes and cutouts are longitudinally arranged at given positions on the attachment portion and direct at least one thread or thin wire to fix the valve prosthesis on the stent, thereby allowing precise positioning of the valve prosthesis on the stent. Each individual attachment hole and notch provided in at least one attachment portion is used to guide threads or a thin wire with which the valve prosthesis is attached or stitched to the attachment portion of the stent. [0026] The means provided to attach the valve prosthesis to the stent fastening portion (thread or thin wire) is guided by means of mounting holes and cutouts so that the longitudinal displacement of the valve prosthesis relative to the stent is substantially minimized. It also enables accurate positioning of the valve prosthesis relative to the stent.

[0027] The secure and defined attachment of the valve prosthesis to at least one stent fastening portion furthermore effectively protects the means used to secure the valve prosthesis on the stent (threads or thin wires) against rubbing against the stent and thereby degradation after prolonged use.

[0028] To configure the plurality of attachment holes and any notches in the attachment portion, at least one attachment portion is preferably configured as - compared to the respective arms of the positioning arch, holding arch, auxiliary holding arch - the widened segment. Thus, the attachment portion is a segment of the stent that contains a relatively large amount of material, which facilitates the analysis of movement and position when the stent is implanted. For example, when fluoroscopy (cardiac catheterization = LHK) or ultrasound (trans-esophageal echocardiogram = TEE) is used to monitor the insertion procedure, the stent fastening portion is particularly recognizable.

[0029] The preferred implementation of the stent according to a particular embodiment of the invention provides for the attachment portion to be configured within each of the arms of the retaining arch of the stent.

[0030] To reinforce the respective arches supporting the stent, an auxiliary arch is provided as already mentioned above. The auxiliary arch extends from the lower ends of the fastening part and connects the respective arms of two adjacent holding arches. [0031] In the manufacture of the stent used in the endoprosthesis according to a particular embodiment of the invention, it is possible that the stent has a structure integrally cut from a part of the tube, especially a small metal tube, which includes positioning arches, retaining arches and auxiliary retaining arches, such as also at least one attachment part with defined attachment holes and cutouts. In particular, it is possible to use a laser to cut out the stent structure from a small metal tube, the structure then being subjected to the applied molding and heat treatment process so that the stent can transform from a collapsed state during implantation in a developed state at the implantation site. This shaping and heat treatment process is preferably carried out gradually to avoid damage to the stent structure.

[0032] It is particularly advantageous for the stent to exhibit a structure integrally cut from a small metal tube in which each positioning arc is assigned to one retaining arch, and in which each part of the upper end of the positioning arch towards the upper end of the stent is connected to the upper part of the stent the end of the associated retaining arc through the first connecting web. The at least one attachment part, in which a plurality of attachment holes are provided, is thus preferably configured inside the arm of the holding arch.

[0033] The stent preferably has an integrally formed structure that can transform from a first predetermined shape to a second predetermined shape, wherein the stent has a first predetermined shape (collapsed shape) when entering the patient's body and a second predetermined shape (expanded shape ) after implantation. Due to the construction of the stent, when the stent passes from the first predetermined shape to the second predetermined shape, the positioning arches, holding arches and auxiliary arches are radially developed depending on the expansion of the stent cross-section. The second shape of the stent is thus preferably chosen so that when the stent is unrolled, the holding arch and the auxiliary arch adjoin the wall of the blood vessel in which the stent is used. In addition, the ends of the holding arches are located below the native valve ring, thereby providing additional anchoring of the stent.

[0034] To achieve secure anchoring of the stent at the implantation site, both the retaining arches and the auxiliary arches should press the vessel wall with radial force, this radial force can be set by subjecting the stent structure to an appropriate shaping and thermal treatment process.

[0035] It should be understood that the term "upper" refers to the stent viewed in its implanted state. In other words, the term "upper" refers to the distal end of the stent, which, after implantation, is located away from the heart. Similarly, the use of the term "lower" refers to a proximal position on the stent that is placed toward the ventricular side when the stent is viewed in its implanted position.

[0036] A preferred embodiment of the stent according to the invention provides that the positioning arches and associated retaining arches, as well as the auxiliary arches, each have a substantially U, T or V-shaped structure which is closed towards the lower end of the stent. Particularly preferred for each positioning arc is the cutting out from a portion of the material of a small metal tube from which a substantially U, T or V-shaped structure is taken from the associated retaining arch. Suitable auxiliary arches are preferably cut from a portion of the material of a small metal tube located between the substantially U, T or V-shaped structures of the holding arch.

[0037] This preferred embodiment of the stent structure thus provides suitable retaining and support stent arches to form the lower endoprosthesis region, the positioning arches being configured symmetrically with respect to the retaining arches, although preferably located slightly further towards the upper endoprosthesis area.

[0038] The respective upper ends of the positioning arches are connected to the respective upper ends of the associated retaining arches by means of a first connecting web in the upper region of the endoprosthesis. The fastening parts are configured with appropriate arms of the holding arch. In the expanded state of the stent, both the lower area with fastening parts, as well as the connecting web located at the upper end of the stent, between the respective positioning and holding arches, spread so that the radially acting force is exerted on the wall of the lower vessel area of ​​the stent, as well as the upper end of the stent, thus enabling safe anchoring of the stent at the implantation site.

[0039] In a preferred embodiment, the stent has in its first shape (rolled up) an outer diameter of approximately 4 to 8 mm and a length between mm and 40 mm, preferably between 34.0 and 39.0 mm, and more preferably between 34, 37 mm and 38.37 mm. This allows the stent to be easily inserted into the patient's body, for example using a 21F delivery system, and used with a prosthetic valve with a diameter between 19 mm and 28 mm. The abovementioned length specifications are currently the preferred dimensions on the basis of which the stent becomes suitable for most patients treated.

[0040] To achieve particularly secure anchoring of the implanted stent with the expanded valve prosthesis attached thereto, it is also conceivable that the stent is an object in the process of shaping and heat treatment during its manufacture, so that the end stent has a slightly concave configuration, narrowing towards its lower end in its second shape.

[0041] In other words, the lower end part of the stent, i.e., the region in which the prosthetic valve is attached, has a slightly conical diameter compared to the upper end part. Specifically, it has been observed that when the stent is in the second shape and the upper end of the stent has a diameter approximately 10-25% larger than the diameter of its lower end, radial forces are generated particularly at the upper end of the stent. This allows a secure connection of the stent in the blood vessel without damaging the artery wall. This configuration also provides a secure anchorage that is able to withstand the peristaltic movement of the heart and artery wall. The slightly smaller radial force exerted by the lower end of the stent is not only used to anchor the stent in a blood vessel, but also stretches the valve prosthesis attached at the lower end and reliably seals the prosthesis against the wall of the artery. It is of course also possible to design a concave configuration of the stent in its second shape of greater or smaller concavity.

[0042] This is advantageous for the area of ​​the lower end of the stent, when placed in a second shape, having a diameter between 22 mm and 33 mm, preferably between 25 mm and mm. It is possible for the stent to have two or more differently dimensioned sizes, with the optimal stent size selected depending on the individual patient. In addition, accurate and patient-specific stent dimensions - starting from a specific stent size - can be accomplished by properly curing the stent, especially through a heat treatment process.

[0043] In a particularly preferred embodiment, the stent comprises a valvular prosthesis, preferably a biological or pericardial valvular prosthesis, which is attached to at least one securing part of the stent by means of threads or the like.

[0044] The shape memory material is preferably used as the material for the stent, the material is designed so that the stent can transform from a temporary shape to a permanent shape under the influence of an external stimulus. The temporary shape is consequently the first shape of the stent (i.e., the collapsed state of the stent), while the permanent shape is assumed in the second shape of the stent (i.e., in the expanded state of the stent). In particular, the use of a shape memory material such as nitinol, i.e. an equimolar alloy of nickel and titanium, allows for particularly gentle implantation procedures after stent implantation.

[0045] During manufacture, the stent is preferably made of shape memory material, the stent structure is preferably formed after being cut from the tube. After the desired shape has been formed, the shape is "fixed", this process is known as "programming". Programming can be done by heating the stent structure, forming the stent to the desired shape and then cooling the stent. Programming can also be accomplished by forming and shaping the stent structure at a lower temperature, which is known as "cold stretching". The permanent shape is therefore remembered, allowing stent storage and implantation in a temporary, unformed shape. If the external stimulus then acts on the stent structure, the shape memory effect is activated and the remembered, permanent shape is restored.

[0046] A particularly preferred embodiment provides an external stimulus as a definable temperature switching. It is therefore understood that the stent material requires heating to a temperature higher than the switching temperature to activate the shape memory effect and thereby regenerate the stored permanent shape of the stent. The specific switching temperature can be set by proper selection of the chemical composition of the shape memory material.

[0047] It is particularly preferred to set the switching temperature in the range between room temperature and the patient's body temperature. This is convenient, especially for a medical device used as an implant in a patient's body. Accordingly, all that needs to be provided in this regard for implanting a stent is to heat the stent to the patient's body temperature (36 ° C) at the implant site to activate the shape memory effect of the stent material.

[0048] In the following, reference will be made in more detail to the attached figures in the description of preferred embodiments of the stent according to the invention.

[0049] Shown are:

Fig. 1a a perspective side view of the cardiac valve stent according to the first embodiment of the invention, wherein the cardiac valve stent is shown in its collapsed state;

Fig. 1b a perspective side view of the cardiac valve stent according to the first embodiment of the invention, wherein the cardiac valve stent is shown in its expanded state;

Fig. 1c a perspective top view of the proximal end of the cardiac valve stent according to the first embodiment of the invention, wherein the cardiac valve stent is shown in its expanded state;

Fig. 1d a perspective side view of an endoprosthesis for treating a narrowed heart valve or heart valve failure, wherein the endoprosthesis comprises a heart valve stent according to a first embodiment of the invention for supporting a valve prosthesis;

Fig. 1e, a two-dimensional projection of a cutting pattern for use in the manufacture of a cardiac valve stent according to a first embodiment of the invention for cutting a cardiac valve stent based on Fig. 1a integrally from a portion of a tube, especially a small metal tube;

Fig. 2a a perspective side view of the cardiac valve stent according to a second embodiment of the invention, wherein the cardiac valve stent is shown in its collapsed state;

Fig. 2b a first perspective side view of a cardiac valve stent according to a second embodiment of the invention, wherein the cardiac valve stent is shown in its expanded state;

Fig. 2c a second perspective side view of the cardiac valve stent according to the second embodiment of the invention, wherein the cardiac valve stent is shown in its expanded state;

Fig. 2d a perspective side view of an endoprosthesis for treating a narrowed heart valve or heart valve failure, wherein the endoprosthesis comprises a heart valve stent according to a second embodiment of the invention for supporting a valve prosthesis;

Fig. 2e, a two-dimensional projection of a cutting pattern for producing a cardiac valve stent according to a second embodiment of the invention to allow cutting of the cardiac valve stent based on Fig. 2a integrally from a portion of the tube, especially a small metal tube;

Fig. 3 a two-dimensional projection of a cutting pattern for producing a cardiac valve stent according to a third embodiment of the invention to allow cutting of the cardiac valve stent integrally from a portion of the tube, especially a small metal tube;

Fig. 4 a two-dimensional projection of a cutting pattern for producing a heart valve stent according to the fourth embodiment of the invention to allow cutting of the heart valve stent integrally from a portion of the tube, especially a small metal tube;

Fig. 5a a first perspective side view of the cardiac valve stent according to the fifth embodiment of the invention by which the cardiac valve stent is shown in its expanded state;

Fig. 5b a second perspective side view of the cardiac valve stent according to the fifth embodiment of the invention by which the cardiac valve stent is shown in its expanded state;

Fig. 5c a top view of the upper end of the heart valve stent according to the fifth embodiment of the invention by which the heart valve stent is shown in its expanded state;

Fig. 5d, a two-dimensional projection of a cutting pattern for use in the manufacture of a cardiac valve stent according to the fifth embodiment of the invention for cutting a cardiac valve stent based on Fig. 5a integrally with a portion of a tube, especially a small metal tube;

Fig. 6a a first perspective side view of the cardiac valve stent according to the sixth embodiment of the invention by which the cardiac valve stent is shown in its expanded state;

Fig. 6b a second perspective side view of the cardiac valve stent according to the sixth embodiment of the invention by which the cardiac valve stent is shown in its expanded state;

Fig. 6c a third perspective side view of the cardiac valve stent according to the sixth embodiment of the invention by which the cardiac valve stent is shown in its expanded state;

Fig. 6d

Fig. 6e

Fig. 6f

Fig. 6g

Fig. 6h

Fig. 6i Fig. 7a

Fig. 7b

Fig. 7c

Fig. 8a

Fig. 8b

Fig. 8c

Fig. 9a

Fig. 9b

Fig. 10

Fig. 11 a two-dimensional projection of a cutting pattern for use in the manufacture of a cardiac valve stent according to a sixth embodiment of the invention for cutting a cardiac valve stent based on Fig. 6a integrally from a portion of a tube, especially a small metal tube;

perspective side view of an endoprosthesis for treating a narrowed heart valve or heart valve failure, wherein the endoprosthesis comprises a heart valve stent according to an embodiment of the invention for supporting a valve prosthesis with which the heart valve stent is shown in a partially expanded state;

perspective side view of an endoprosthesis for treating a constricted heart valve or heart valve failure, wherein the endoprosthesis comprises a heart valve stent according to a sixth embodiment of the invention for supporting a valve prosthesis with which the heart valve stent is shown in its expanded state;

a perspective perspective view of a part of the head of the retaining arch belonging to the cardiac valve stent of the endoprosthesis shown in Fig. 6f; a perspective perspective view of an additional attachment portion belonging to the cardiac valve stent of the endoprosthesis shown in Fig. 6f;

a top view of the lower end of the endoprosthesis shown in Fig. 6f;

a two-dimensional projection of a cutting pattern for producing a cardiac valve stent according to a seventh embodiment of the invention to allow cutting of the cardiac valve stent integrally from a portion of the tube, especially a small metal tube;

a first perspective side view of the cardiac valve stent according to the seventh embodiment of the invention by which the cardiac valve stent is shown in its expanded state;

a second perspective side view of the cardiac valve stent according to the seventh embodiment of the invention by which the cardiac valve stent is shown in its expanded state;

a two-dimensional projection of a cutting pattern for producing a cardiac valve stent according to an eighth embodiment of the invention to allow cutting of the cardiac valve stent integrally from a portion of the tube, especially a small metal tube;

a first perspective side view of the cardiac valve stent according to the eighth embodiment of the invention by which the cardiac valve stent is shown in its expanded state;

a second perspective side view of the cardiac valve stent according to the eighth embodiment of the invention by which the cardiac valve stent is shown in its expanded state;

a two-dimensional projection of a cutting pattern for producing a cardiac valve stent according to a ninth embodiment of the invention to allow cutting of the cardiac valve stent integrally from a portion of the tube, especially a small metal tube;

a perspective side view of the cardiac valve stent according to the ninth embodiment of the invention by which the cardiac valve stent is shown in its expanded state;

a two-dimensional projection of a cutting pattern for producing a heart valve stent according to the tenth embodiment of the invention to allow cutting of the heart valve stent integrally from a portion of the tube, especially a small metal tube;

a two-dimensional projection of a cutting pattern for producing a cardiac valve stent according to an eleventh embodiment of the invention to allow cutting of the cardiac valve stent integrally from a portion of the tube, especially a small metal tube; and

Fig. 12a-c. A process flow illustrating the transarterial implantation of an endoprosthesis comprising a cardiac valve stent according to some embodiments of the invention.

[0050] Both right and left halves of the human heart consist of a ventricle and an atrium. These cavities are separated by a septum of the heart, divided into an atrial septum (septum interatriale) and a ventricular septum (septum interventriculare).

[0051] Blood can only flow in one direction through the chambers of the heart because of the heart valves located between the atria and the ventricles of the heart, and in the blood vessels connected to the ventricles that act mechanical valves. The upper and lower vena cava (vena cava superior et inferior) connects to the right atrium. They supply oxygen depleted (venous) blood from the systemic circulation to the heart. The tricuspid valve, which, like a mechanical valve, prevents backflow of blood to the atrium after ventricular contraction (systole) is located between the right atrium and the right ventricle. It contains three segments that are attached like flaps to the ventricular musculature via ligaments (hence also called the "flap valve"). Both pulmonary arteries leave the right ventricle through the common trunk (truncus pulmonalis). There is also a valve between the ventricle and the pulmonary trunk, the so-called pulmonary valve. This type of valve is also called crescent valve because of its shape. The pulmonary arteries supply oxygen depleted blood to the pulmonary circulation.

[0052] Oxygen-rich (arterial) blood then flows through the four pulmonary veins from the pulmonary circulation to the left atrium. From there, it reaches the left ventricle through the distal flap valve, mitral valve. The outflow occurs through the aorta, which, like the pulmonary artery, has a crescent valve (aortic valve).

[0053] During the cardiac cycle, the atria fill up first, while the ventricles simultaneously discharge blood into the arteries. When the ventricular musculature relaxes, the flap valves open due to a decrease in ventricular pressure and blood flows from the atria (auricular systole). This is supported by atrial contraction. The ventricular contraction is as follows: the ventricular muscle contracts, the pressure increases, the flap valves close and blood can now only flow into the arteries through the now open crescent valves. Backward blood flow from the arteries during the relaxation phase (diastole) is prevented by closing these crescent valves so that the flow direction is determined solely by the valves.

[0054] Four heart valves act as mechanical valves in the heart and prevent reverse flow of blood in the wrong direction. Each half of the heart has an atrioventricular valve and a crescent valve. Atrioventricular valves are located between the atrium and the ventricle and are called a mitral / mitral valve and a tricuspid valve. The crescent valves are located between the ventricle and the outflow of vessels and are called pulmonary artery and aortic valves, respectively.

[0055] Valve defect; i.e. heart valve dysfunction may affect any of the four heart valves, although it is more common for the valves on the left side of the heart (aortic and mitral valve) than those on the right side of the heart (pulmonary and tricuspid valve). Dysfunction may include stenosis, failure or a combination of both (combined vitium).

[0056] In medicine, the term "aortic valve insufficiency" or "aortic insufficiency" in brief refers to defective cardiac valve closure and results in diastolic backflow of blood from the aorta to the left ventricle. Depending on the severity of aortic insufficiency and the extent of resistance to aortic collapse, the amount of retrograde flow may be up to two-thirds of left ventricular ejection volume (normal cardiac output 40 to 70 ml). This results in a characteristically high blood pressure amplitude. This retrograde blood flow increases the diastolic filling of the left ventricle and leads to volume overload of this part of the heart resulting in eccentric hypertrophy.

[0057] Aortic stenosis is a valve disease of the heart caused by incomplete opening of the aortic valve. When the aortic valve narrows, it causes a pressure gradient between the left ventricle and the aorta. The more narrowed the valve, the greater the gradient between the left ventricle and the aorta. For example, with mild aortic stenosis, the gradient may be 2.67 kPa (20 mmHg). This means that at peak contraction, when the left ventricle can produce a pressure of 18.7 kPa (140 mmHg), the pressure that is transmitted to the aorta will be only 16.0 kPa (120 mmHg).

[0058] In subjects with aortic valve stenosis, the left ventricle must generate increased pressure to overcome growth after loading caused by the aortic stenosis and to push blood out of the left ventricle. The more severe the aortic stenosis, the higher the gradient between left ventricular and aortic systolic pressures. Due to the increased pressure generated by the left ventricle, myocardium (muscle) of the left ventricle undergoes hypertrophy (increase in muscle mass).

[0059] Angina in aortic stenosis position is secondary to left ventricular hypertrophy, which is caused by the constant generation of increased pressure required to overcome the pressure gradient caused by aortic stenosis. While the myocardium (i.e. myocardium) of the left ventricle becomes thicker, the arteries supplying the muscle do not become significantly longer or larger, so the muscle may be ischemic (i.e. not receiving adequate blood supply). Ischemia may first be seen during exercise, when the heart muscle requires an increased blood supply to compensate for the increase in load. The subject may complain of exertional angina. At this stage, an imaging exercise test may suggest ischemia.

[0060] Mitral valve failure (also called mitral failure) is often a heart valve defect in the treatment of humans and also at least several animal species. This is associated with a defect in occlusion or "leakage" of the mitral heart valve, which leads to retrograde blood flow from the left ventricle to the left atrium during the ejection phase (contraction).

[0061] The mitral valve acts as a mechanical valve between the left atrium and the left ventricle. It opens during the ventricular filling phase (diastole) and thus allows blood to flow from the atrium. At the beginning of the ejection (contraction) phase, a sudden increase in ventricular pressure leads to valve closure and thus to "sealing" the atrium. Therefore, the pressure of only about 1.07 kPa (8 mmHg) occurring in the atrium, while at the same time the systolic pressure of about 16.0 kPa (120 mmHg) in the chamber displaces the blood along its usual path to the main artery (aorta). [0062] In cases of severe mitral insufficiency, however, the ejection opening is larger than 40 mm² and the volume of ejection is greater than 60 ml, which can lead to serious and sometimes life-threatening changes.

[0063] In the acute phase with the normal size of the left ventricle and left atrium, there is a significant increase in pressure in the atrium and thus also in the pulmonary veins. This can be up to 13.3 kPa (100 mmHg), which, given normal pulmonary conditions, leads to immediate pulmonary edema. First of all, retrograde blood flow may then lead to insufficient drainage to the aorta and thus reduced flow to all organs.

[0064] In the treatment of severe cardiac valve stenosis or valve insufficiency, the valve prosthesis must necessarily function as a constricted valve, diseased or diseased heart valve. Important in this regard is that the valve prosthesis is securely positioned and anchored at the implant site in the heart; i.e. in the plane of the (diseased) cardiac valve requiring replacement so that the prosthetic valve is not displaced or displaced despite the sometimes significant forces acting on it. Effective sealing during shrinkage is also important.

[0065] A cardiac valve stent 10 is used to which a valve prosthesis 100 according to at least some embodiments of the invention is appropriately attached to position and anchor this valve prosthesis. A medical device for treating a constricted heart valve or heart failure comprising a heart valve stent 10 and a valve prosthesis 100 attached to the stent 10 will hereinafter be referred to simply as endoprosthesis 1 in this specification.

[0066] Fig. 1d shows a perspective side view of such an endoprosthesis 1 for the treatment of cardiac valve stenosis or cardiac valve insufficiency, wherein the endoprosthesis 1 comprises a cardiac valve stent 10 for holding the valve prosthesis 100 according to the first embodiment of the invention. FIG. 2d also shows a perspective side view of the distal endoprosthesis 1 for the treatment of cardiac valve stenosis or cardiac valve insufficiency, wherein the cardiac valve stent 10 of the second embodiment of the invention is used.

[0067] The following description will refer to figures describing in detail the preferred embodiments of the invention. The cardiac valve stent 10 according to some embodiments of the invention (hereinafter simply referred to as "stent") has an expandable structure that is capable of transforming from a first predetermined shape in which the stent 10 is in a collapsed state into a second predetermined shape, wherein stent 10 is in the expanded state. FIG. 1a shows a side view of the stent 10 according to the first embodiment of the invention, the stent 10 being rolled up. Fig. 2a shows the wound stent 10 according to the second embodiment according to the invention.

[0068] In both embodiments, the stent 10 is introduced minimally invasively into the patient's body in its first shape (cf. Fig. 1a and Fig. 2a) using a catheter insertion system (this is not clearly shown in the figures). During insertion, the valve prosthesis 100 attached to the stent 10 is also in its rolled up state. For the sake of clarity, however, both Figures 1a and 2a depart from representing the valve prosthesis 100 attached to the stent 10.

[0069] Upon reaching the implantation site in the patient's heart, the stent 10 is transformed, through increments, into its second (developed) shape, in which also the valvular prosthesis 100 attached to the stent 10 also unfolds and expands. The second expanded shape is a permanent shape that has been set by programming. The fully developed stent 10 according to the first / second embodiment of the invention with a similarly fully unfolded and unfolded valve prosthesis 100 attached thereto is shown in Fig. 1d and Fig. 2d.

[0070] Figs. 1b and 1c show the fully developed stent 10 according to the first embodiment of the invention from different perspectives without valve prosthesis 100. Figures 2b and 2c show the fully developed stent 10 according to the second embodiment according to the invention, also without valve prosthesis 100, from different perspectives.

[0071] The following description will refer to Figures 1a to 1e when describing the first embodiment of stent 10.

[0072] The stent 10 of the first embodiment has a structure integrally cut from a portion of the tube, especially a small metal tube. The cutting pattern used to form the stent design is depicted in the two-dimensional projection in Fig. 1e.

[0073] In detail, the stent 10 comprises three positioning arches 15a, 15b, 15c that assume the function of self-positioning the stent in the plane of the pulmonary valve (valva trunci pulmonalis) or the aortic valve (valva aortae). The positioning arches 15a, 15b, 15c show a rounded head portion 20 that is secured in the pockets of the T (diseased) heart valve to be treated during positioning of the stent 10 at the implant site in the heart (cf. Fig. 12a).

[0074] As well as providing symmetry that fits the native valve, providing three positioning arches 15a, 15b, 15c also provides rotational accuracy, symmetry and stability. Stent 10 is obviously not limited to use together with three positioning arches.

[0075] The head portions 20 of the positioning arches 15a, 15b, 15c, respectively, facing the lower end 2 of the stent 10 are rounded so that the vessel wall will not be damaged when the positioning arches 15a, 15b, 15c fixed in the heart valve T pockets will be mentioned. To improve flow and position analysis during implantation of the stent 10, reference markers 21 are provided on or in the head portions 20 of the positioning arches 15a, 15b, 15c. X-ray contrast markers or markers that can be activated by infrared or ultrasound are particularly well suited for this.

[0076] The positioning arches 15a, 15b, 15c, respectively, generally have a U or V-shaped structure which is closed at the lower end of the stent 10. Accordingly, each positioning arch 15a, 15b, 15c has a total of two arms respectively 15a ', 15a ", 15b ', 15b", 15c', 15c ", extending from the head portion 20 of the associated positioning arc 15a, 15b, 15c towards the upper end 3 of stent 10. As a result, each two adjacent arms of two adjacent positioning arches are connected to each other via a connecting portion 22.

[0077] For implantation and implantation of the stent 10 by means of a suitable catheter system, the stent 10 comprises means 23 holding the catheter at its upper end 3. The connecting parts 22 are respectively connected to the means 23 holding the catheter through the connecting web 25. The connecting webs 25 will be further referred to as "the second connecting web 25".

[0078] The catheter retaining means 23 comprise oval shaped heads, each of which has a respective oval shaped eyelet 24. The shape of the catheter retaining means 23 completes the crown at the tip of the catheter of the catheter system used for implantation / explantation of the stent 10. The crown of the catheter tip has protruding elements that are configured opposite to the catheter retaining means 23. Alternatively, the protruding elements are shaped complementary to the meshes 24 and are configured as heads holding the catheter. This implementation allows the protruding crown elements to form a detachable coupling with the upper region 3 of the stent 10 to allow detachable attachment of the stent 10 to the catheter tip.

[0079] The first connecting web 17 extends substantially in the longitudinal direction L of the stent 10 and has an upper end portion 17d and a lower end portion 17p. The upper end portion 17d opens to the connecting portion 22 between the two arms 15a ', 15a ", 15b', 15b", 15c ', 15c "of two adjacent positioning arches 15a, 15b, 15c, in addition to the aforementioned second connecting web 25. As can be seen in fig. 1b, the first connecting webs 17 have a substantially inverted Y-shaped configuration and each has a structure that differs in its lower end 17p giving way to the respective arms 16a ', 16a ", 16b', 16b", 16c ', 16c "two adjacent supporting arches 16a, 16b, 16c.

[0080] Between each positioning arch 15 and the utilizing arch 16 is a fastening arch 19. As shown particularly clearly in Fig. 1b, the fastening arch depends on the proximal end of the fastening part 11 and has a generally U-shaped or V-shaped structure which closes to the lower end of the stent 10. As shown in Figure 1d, the fastening arches serve to support the lower end of the valve prosthesis 100. The prosthesis 100 is shaped so that the fastening arches 191, 19b and 19c are located in the pockets of the valve material. The fastening arches 19a, 19b and 19c have an elongated shape that allows the arches to lie in line with the circumference of the stent 10. Hence, when the arches 19 are seated inside the positioning and holding arches, thereby keeping the valve material away from the stent structure. This reduces the wear of the valve material by the stent after implantation of the prosthesis 1.

[0081] This stent design achieves an axially symmetrical structure, each positioning arch 15a, 15b, 15c being assigned to one attachment arch 19a, 19b, 19c and one retaining arch 16a, 16b, 16c. The stent 10 of the first embodiment depicted in Figs. 1a to 1d thus includes a total of three retaining arches 16a, 16b, 16c, which constitute the retaining segment of the stent 10 for placing valve prosthesis 100, as illustrated, for example, in Fig. 1d.

[0082] In the condition of the stent 10 shown in Fig. 1a, in which the stent 10 is in its first (rolled up) condition, the respective arms 15a ', 15a ", 15b', 15b", 15c ', 15c "positioning arches 15a, 15b , 15c are directly adjacent to the respective arms 19a ', 19a ", 19b', 19b", 19c ', 19c "fastening arches 19a, 19b, 19c, which in turn are directly adjacent to the respective arms 1a', 16a", 16b ', 16b ", 16c ', 16c" associated holding arches 16a, 16b, 16c.

[0083] Reference is made to Fig. 1b, in which the stent 10 according to the first embodiment is shown in a second expanded shape. It can in particular be recognized from this representation that each positioning arch 15a, 15b, 15c and correspondingly associated mounting arch 19a, 19b, 19c and holding arch 16a, 16b, 16c generally have a U or V-shaped structure, which is closed towards the lower end of 2 stent 10. Specifically, each positioning arc 15a, 15b, 15c is cut from the material of the cross section of the tube part from which the U or V-shaped structure is generally made, the associated fastening arch 19a, 19b, 19c, as shown by the cutting pattern depicted in Fig. 1e.

[0084] The comparison of Fig. 1a to Fig. 1b shows that after expanding the stent 10; i.e., when the stent 10 passes from its first shape to its second shape, the stent 10 shortens in the longitudinal direction L while simultaneously expanding in cross-section. In the expanded state of stent 10, the positioning arches 15a, 15b, 15c are more developed in the radial direction at the lower end of 2 stent 10 compared to the upper end of 3 stent 10. Because they project in the radial direction, the positioning arches 15a, 15b, 15c can be arranged in the heart pockets T of the heart valve, which can be exchanged particularly easily.

[0085] Even when some anchoring of the stent 10 is achieved at the implant site in the heart due to the positioning arches 15a, 15b, 15c already protruding radially from the stent 10 in the expanded state of the stent 10, it is noted that the pressure force acting on the vessel wall from positioning arches 15a, 15b, 15c is insufficient to securely anchor stent 10 at the implantation site. For this reason, the abovementioned retaining arches 16a, 16b, 16c are provided, which form the lower end 2 of the stent 10. The retaining arches 16a, 16b, 16c protrude radially from the circumference of the stent 10 in their expanded state such that the retaining arches 16a, 16b, 16c press against the wall of the blood vessel in which the stent is deployed by means of a radial pressure force. In addition, the closed ends of the retaining arches 16a, 16b, 16c flicker outward, projecting radially further from the perimeter of the stent 10. This shape allows the ends of the retaining arches 16a, 16b, 16c to position below the native valve ring or to position at least native valve ring, which provides additional anchoring for stent 10.

[0086] In addition to the retaining arches 16a, 16b, 16c, the stent 10 further includes auxiliary arches 18a, 18b, 18c, which also exert a radial pressure on the wall of the blood vessel in the implanted state of the stent 10, thereby further improving anchoring of the stent 10 at the implantation site .

[0087] As can be seen from Fig. 1b, the stent 10 contains a total of three, generally U or V-shaped, auxiliary arches 18a, 18b, 18c, which are closed towards the lower end of the 2 stent 10. Each auxiliary arch 18a, 18b, 18c connects the first holding arch 16a, 16b, 16c to the second holding arch adjacent the first holding arch.

[0088] In a top view of the lower end region 2 of the expanded stent 10 (cf. Fig. 1c), the lower end region 2 has a structure of a 12-sided polygon formed of individual arms 16a ', 16a ", 16b', 16b", 16c ', 16c "supporting arches 16a, 16b, 16c and individual arms 18a ', 18a", 18b', 18b ", 18c ', 18c" auxiliary arches 18a, 18b, 18c. This stent design especially provides a total of six arches 16a, 16b, 16c, 18a, 18b, 18c evenly developed around the lower region 2 of the end of the stent 10, each of which presses against the vessel wall and effectively holds the stent 10 in the expanded and implanted state of the stent 10.

[0089] To sum up, providing supporting arches 16a, 16b, 16c on one side and on the other auxiliary arches 18a, 18b, 18c results in a radial force exerted on the vessel wall by the respective lower end portions of these arches. This ensures both secure sealing of the valve prosthesis 100 attached to the stent 10 relative to the vessel wall, as well as secure anchorage of the stent 10 at the implant site in the heart.

[0090] In addition to the pressure exerted on the vessel wall by the holding arches 16a, 16b, 16c and auxiliary arches 18a, 18b, 18c, it is possible, in the area of ​​the upper end 3 of the stent 10, to develop in a radial direction from 10% to 25% more - in the expanded state of the stent 10 - compared to the lower 2 end region. This gives the stent 10 a slightly concave structure that tapers toward the lower end 2 region. This ensures that the stent 10 is securely anchored to the vessel through the upper region 2 of the end of the stent 10 pressing against the vessel wall.

[0091] To ensure that minimal longitudinal displacement of the valvular prosthesis attached to the stent 10 can occur relative to the stent 10, even during peristaltic movement of the heart and blood vessels in which the stent 10 is used, the embodiment of the stent 10 according to the invention illustrated in the figures provides that the stent 10 includes a plurality of attachment parts 11 extending in the longitudinal direction L of the stent 10 with which the valve prosthesis 100 is attached to the stent 10. Reference is made to Figure 1d which shows a perspective side view of an endoprosthesis 1 for the treatment of narrowed heart valve or heart valve failure. The endoprosthesis 1 comprises a stent 10, according to a first embodiment of the invention, supporting the valve prosthesis 100. The valve prosthesis 100 includes at least one valve flap 102 made of biological or synthetic material.

[0092] It should be understood that the valve prosthesis may be made of any suitable material, including biological valves removed from animals such as pigs and horses, artificial biological valves formed from connective tissue such as pericardium, tissue cultured from cell cultures and artificial materials and textiles such as nitinol. [0093] In detail, the first connecting webs 17 of the stent 10 connect to the connecting parts 22 via the upper ends 17d and with the upper ends 13 of the attachment parts 11 via their lower ends 17p. The respective lower ends 14 of the attachment parts that are connected to one and the same connecting web 17 are thereby connected to each other via a substantially U or V-shaped auxiliary arch 18a, 18b, 18c which is closed towards the lower end 2 stent 10.

[0094] In particular, the first embodiment of the stent 10 according to the invention is shown in Fig. 1d in its expanded state, as a result of which the valve prosthesis 100 is attached to the stent 10 by means of a thread 101 or a thin wire and stretched through the stent 10. It is easy to see that the widening of the central area and lower region 2 of the end of the stent 10 in which the valve prosthesis 100 is located implements the valve prosthesis. At the same time, when the lower end portions of the supporting arches 16a, 16b, 16c and auxiliary arches 18a, 18b, 18c exert a radial force on the vessel wall (not shown in Fig. 1d).

[0095] As can be seen from Fig. 1d, the defined series of fastening holes 12 are configured in the respective fastening parts 11 of the stent 10 and they are adapted to be arranged in predetermined positions along the fastening parts 11. Thread 101 or thin wire, by means of whose valve prosthesis 100 is attached to the stent 10 is guided through each respective mounting hole 12.

[0096] Both components make up the endoprosthesis 1, namely the stent 10 and the prosthesis

100 the valves are preferably not associated with each other until immediately prior to the surgical procedure. This is advantageous in terms of transport and storage, since stent 10 is a relatively mechanically strong element and can be stored for a long time without degradation. This is especially true when the stent 10 is stored in its second state; ie. in the expanded state, not reduced to its first (rolled up) shape right before the surgical procedure. [0097] It can be seen in Figures 1b and 1d that the respective fastening parts 11 are configured in the respective arms 16a ', 16a ", 16b', 16b", 16c ', 16c "of the holding arches 16a, 16b, 16c of the stent 10 The size of the fastening holes 12 configured in the fastening parts 11 should be adapted to the thickness of the thread

101 or wire used to attach the valve prosthesis 100 to the stent 10.

[0098] The cross-sectional shape of the attachment holes 12 may also be adapted to the cross-sectional shape of the thread 101 or wire used to attach the valve prosthesis 100. This allows the valve prosthesis 100 to be attached to the stent 10 at a predetermined position relative to the stent 10. By providing a plurality of attachment holes 12 for anchoring the valve prosthesis 100 relative to the 10, accurate positioning of the valve prosthesis on the stent 10 is achieved.

[0099] Because the attachment holes 12 are adapted to the thickness and / or cross-sectional shape of the thread 101 or wire used to attach the valve prosthesis 100 to the stent 10, relative displacement between the stent 10 and the valve prosthesis 100 can be effectively prevented due to the peristaltic movement of the heart when endoprosthesis 1 is implanted. The valve prosthesis 100 is therefore attached to the stent 10 with minimal mobility, based on which the consumption of the thread 101 or wire used to secure the valve prosthesis is minimized. As shown in the figures, the attachment holes 12 have a round shape in cross-section.

[0100] As already mentioned, the fastening holes 12 configured in the respective fastening parts 11 may be of different diameter, in different numbers or in cross-sectional shapes (oval, square, etc.) depending on the diameter of the thread 101 used to secure the valve prosthesis 100 to stent 10 and / or depending on the sewing techniques used to attach the valve prosthesis 100 to the stent 10. The diameter, number and / or cross-sectional shape of at least one of the attachment holes 12 may also serve as an indication of the type of endoprosthesis 1, i.e. a medical device used in the treatment of cardiac valve stenosis and / or cardiac valve insufficiency. Therefore, the diameter, number and / or cross-sectional shape of the at least one mounting hole 12 can be used to identify a distinction between different sizes or types of valve prostheses 100 adapted to be attached to a stent 10, or can be used to identify a distinction between different sizes or endoprosthesis types 1 if the valve prosthesis 100 is already attached to the stent 10. For example, small-sized stent 10 having a small-sized prosthetic valve 100 or small-sized stent 10 adapted and configured to carry a small-sized prosthetic valve 100 may have round mounting holes 12, while large-sized stent 10 having a large fixed prosthesis 100 valve size 100 or large stent 10 adapted and configured to carry a large size 100 valve prosthesis, may have triangular fixing holes

12. This allows surgical / cardio personnel to easily and visually distinguish between different valve sizes, types of stents and / or types of endoprostheses without measuring. [0101] The fastening parts 11 of the stent 10 (on which the valve prosthesis 100 is sewn or suture) do not change their shape when the stent 10 is compressed, e.g. when the stent 10 is in its first (rolled up) shape shown in Fig. 1a. This phenomenon occurs when standard tubular stents are used. Therefore, the risk of thread wear is minimal.

[0102] The stent 10 according to the second embodiment is depicted in figures 2a to 2c and is similar in structure and function to the first embodiment stent 10 depicted in figures 1a to 1c. The same applies to the cutting pattern shown in Fig. 2e, which is, in principle, comparable to the cutting pattern according to Fig. 1e. A detailed description of the common features will therefore not be provided.

[0103] A visible difference is in the configuration of the catheter retaining means 23 provided at the distal end 3 of the stent 10. Unlike the first embodiment of the stent 10 of the invention, the heads of the substantially circular configuration are used as the catheter retaining means 23 in the second embodiment in in each case they are equipped with essentially oval eyelets 24. Due to the round configuration of the heads, the risk of injury or damage is reduced. Hence, the generally round head configuration is more atraumatic.

[0104] As already indicated, the stent 10 according to some embodiments of the invention preferably has a structure integrally cut from a portion of the tube, especially a small metal tube. Attachment arch 19a, 19b, 19c and retaining arch 16a, 16b, 16c are assigned to each positioning arch 15a, 15b, 15c, and each retaining arch 16a, 16b, 16c is connected to the adjacent retaining arch by an auxiliary arch 18a, 18b, 18c. The fastening portion 11 with the specified number of fastening holes 12 is configured in each arm 16a ', 16a ", 16b', 16b", 16c ', 16c "of the holding arch 16a, 16b, 16c.

[0105] Figs. 1e and 2e show a two-dimensional projection of a cutting pattern that can be used to manufacture the stent 10 of the first or second embodiment of the invention. This allows one-piece stent 10 to be cut from a portion of the tube, especially a small metal tube. It is obvious that, on the one hand, the stent 10 according to the invention does not have fixed joints of the body or other similar connecting devices between the individual elements of the stent 10 (positioning arch, holding arch, auxiliary arch). On the other hand, a stent 10 is provided that has, with minimal longitudinal expansion, the positioning functionality provided by the positioning arches 15a, 15b, 15c on one side and on the other, the functionality of the specific attachment of the prosthetic valve 100 provided by the attachment parts 11, configured in respective arms 16a ', 16a ", 16b', 16b", 16c ', 16c "holding arch 16a, 16b, 16c.

[0106] In addition to its holding arches 16a, 16b, 16c, the stent 10 further includes auxiliary arches 18a, 18b, 18c, which allow particularly secure anchoring of the stent 10 at the implantation site in the heart.

[0107] The stent 10 of the third embodiment of the invention also includes a one-part structure cut from a portion of the tube, especially a small metal tube. The notching pattern used to form the stent design is shown in the two-dimensional projection in Fig. 3. The differences between the third embodiment of the stent and the first or second embodiment can be seen by reference to the two-dimensional notch pattern shown in Fig. 3. As is also the case with the first or second embodiment, the third embodiment of the stent 10 has a total of three positioning arches 15a, 15b, 15c that perform the function of automatically positioning the cardiac valve stent in the plane of the pulmonary valve or aortic valve.

[0108] Stent 10 is made of nitinol and the positioning arches 15a, 15b, 15c are programmed during manufacture, by appropriate heat treatment of the positioning arches 15a, 15b, 15c so that in the expanded state of the stent, i.e. when the permanent shape has been adopted After exceeding the switching temperature, the positioning arches not only diverge in the radial direction, as illustrated in Figs. 1b, 1d and 2b, 2d, but at the same time bend slightly convex towards stent 10. This measure allows parts 20 of the positioning arches 15a, 15b, 15c to lie perfectly parallel to the longitudinal axis L of the expanded stent 10. As a result, during implantation of the stent 10 of the heart valve, parts 20 of the positioning arches of the 15a, 15b, 15c can be particularly easily inserted into the T pocket of the native H heart valve (see Fig. 12a). This particularly minimizes damage to the surrounding tissue when the positioning arches 15a, 15b, 15c are inserted into the pockets T of the native heart valve H. The shape also allows the positioning arches 15a, 15b, 15c to exert an additional cutting force of the native valve flakes by squeezing the native petal at the bottom of each arch.

[0109] In addition, the convex curvature of the positioning arches 15a, 15b, 15c allows particularly secure support of the stent 10 at the implantation site because the positioning arches 15a, 15b, 15c are better adapted to the anatomy of the T pockets of native H valves and their surroundings.

[0110] As in the stent 10 according to the first and second embodiment (see, for example, Figures 1b, 1c, 1d and 2b, 2c, 2d), the stent 10 according to the third embodiment has a catheter retaining means 23 with eyelets 24. Similar to in the case of the previously described embodiments, a suitable catheter system may be detachably connected to the catheter retaining means 23 to facilitate minimally invasive, intravascular implantation and explantation of the stent 10.

[0111] Because with the stent 10 according to the first or second embodiment, the retaining arches 16a, 16b, 16c and the auxiliary arches 18a, 18b, 18c serve to secure the radial attachment of the stent 10 at the implantation site and to stretch the valve prosthesis attached to the stent by means of arches 19a, 19b, 19c. No further discussion is needed to clarify that the retaining arches 16a, 16b, 16c and the auxiliary arches 18a, 18b, 18c according to this embodiment of the stent also act as sealing of the implanted valve prosthesis. Similarly, retaining arches 16a, 16b, 16c and positioning arches 15a, 15b, 15c clamp the native H heart valve like a paper clip and consequently contribute to secure anchoring of stent 10 at the implant site in the heart.

[0112] The stent 10 of the third embodiment differs from the first and second embodiments in that the respective arms 16a ', 16a ", 16b', 16b", 16c ', 16c "of each holding arch 16a, 16b, 16c extend from the fastening portion 11 to the lower end 2 of the heart valve stent and are connected to each other by a connecting portion 30. The connecting portion 30 has a different shape compared to the U or V-shaped connecting parts 30 in the embodiments of Fig. 1b, 1c, 1d and 2b, 2c, 2d. In particular, the connecting portion 20 has an indentation just above the respective connecting portion 30 'of the fastening arch. The indentations in the holding and fixing arches accommodate the enlarged head 31 at the lower end of each auxiliary arch 18a, 18b, 18c.

[0113] Looking in detail in Figure 3, each connecting portion 30 that connects the two arms 16a ', 16a ", 16b', 16b", 16c ', 16c "of the holding arch 16a, 16b, 16c has a configuration in almost O-shaped. This shape provides more space for attaching the prosthetic valve 100 to the stent 10 and also effectively prevents peak loads that may occur in the implanted endoprosthesis state when transferring loads between the prosthetic valve and the stent.

[0114] The alternative shape of the connecting portion 30 further increases the effective contact surface between the lower end of the holding arch 16a, 16b, 16c and the vessel wall when the stent is positioned at the implantation site in its expanded state. Therefore, a better seal can be obtained between the stent with the attached prosthetic valve and the vessel wall. In addition, the radial forces acting in the expanded state of the stent, which are transferred by the retaining arches 16a, 16b, 16c to the vessel wall, are distributed on a separate contact surface, thus preventing the creation of peak loads. The risk of damage to the holding arches 16a, 16b, 16c of the vessel walls is also reduced.

[0115] Each connecting portion 30 'that connects two arms 19a', 19a ", 19b ', 19b", 19c', 19c "with the mounting arch 19a, 19b, 19c has a more angular shape that helps anchoring the prosthesis 100 valves for stent 10.

[0116] Alternative shapes of the closed ends of the holding and fixing arches (16, 19) accommodate enlarged heads 31 of shortened auxiliary arches 18a, 18b, 18c. The enlarged head 31 allows auxiliary arches to assist the valve material 100, also providing additional radial force. The heads 31 include mounting holes 12 for additional attachment of the prosthesis valve 100, which is further stabilized by the prosthesis valve 100 attached to the stent. These additional attachment holes 12 also reduce the likelihood of misalignment of valve 100 within stent 10 and minimize any longitudinal movement of valve 100 after implantation of endoprosthesis 1. In addition, and as already described in relation to the retaining arches 16a, 16b, 16c, an enlarged contact surface is provided by the widened portions of the head 31, which improves the attachment of the stent 10 at the implantation site, while minimizing the risk of vessel wall damage.

[0117] As can be seen from the cutting pattern in Fig. 3, the upper arms parts of the respective retaining arch 16a, 16b, 16c are attached to the lower region 14 in the associated attachment part 11, while the upper arms parts of the auxiliary arches 18a, 18b, 18c are attached to the central area of ​​the associated fastening part 11. By this it is possible to form a secure connection between the arms 16a ', 16a ", 16b', 16b", 16c ', 16c "and the arches 16a, 16b, 16c and between the arms 18a', 18a", 18b ', 18b ", 18c' , 18c "auxiliary arches 18a, 18b, 18c and fastening part 11 without having to increase the total size of the stent 10.

[0118] Still a further difference between the stent according to the third embodiment and the stents according to the first and second embodiment is the inclusion of notches 26. As shown in Fig. 3, the notches 26 are located at the lower end of the attachment part 11 and are formed in the arms of the auxiliary arches 18a , 18b, 18c and holding arches 16a, 16b, 16c. To ensure that the stent strength is maintained, the cutouts are shaped in the shoulders rather than cut from the shoulders. The cut-outs 26 function as additional guides and fastening points for sewing thread or wire.

[0119] To accommodate the notches 26, the auxiliary arches 18a, 18b, 18c extend from the fastening portion 11 halfway along the length of the fastening portion 11 rather than from the bottom end of the fastening portion 11. This provides each additional arch 18a, 18b, 18c with sufficient flexibility that would otherwise lack a shorter auxiliary arc.

[0120] Fig. 4 shows a two-dimensional projection of a cutting pattern suitable for the manufacture of the stent 10 according to the fourth embodiment of the invention.

[0121] The fourth embodiment of the stent 10 is similar to the third embodiment. However, the stent of the fourth embodiment includes additional attachment holes 12a provided to secure the valve prosthesis. Specifically, additional fastening holes 12a are at the lower end 17p of the first connecting webs 17. Additional fastening holes 12a are configured as eyelets on the first connecting webs 17 between the fastening portion 11 and the connecting portion 22. It is of course understood that the additional fastening holes 12a are not configured as eyelets but are directly formed in the first connecting webs. These additional attachment holes 12a allow additional attachment of the upper region of the valvular prosthesis to the stent 10.

[0122] The size of the additional attachment holes 12a may be adapted to the thickness of the particular thread or wire used to attach the valve prosthesis to the stent 10. The cross-sectional shape of the additional attachment holes 12a may also be adapted to the cross-sectional shape of the thread or wire used to attach the prosthesis valve. Due to the presence of several additional attachment holes 12a for attaching the valve prosthesis to the cardiac valve stent, the attachment of the position of the valve prosthesis to the cardiac valve stent can be accurately determined.

[0123] As an alternative to attachment holes 12a, the same area of ​​the stent 10 may be provided with one or more additional notches. The cut-outs perform the same function as the mounting holes 12a and help by additional anchoring of the valve prosthesis inside the stent 100.

[0124] The stent 10 according to the fifth embodiment of the invention is shown in figures 5a-c with the stent 10 in its expanded state. Figs. 5a and 5b show side views of the stent 10, while Fig. 5c shows a top view of the upper end 3 of the stent 10. Fig. 5d shows a two-dimensional projection of a cutting pattern suitable for producing the stent according to the fifth embodiment of the invention, the stent for cutting integrally from a part of the tube, especially a small metal tube.

[0125] The stent 10 of the fifth embodiment is structurally and functionally comparable to the stent of the third embodiment. In particular, the stent 10 of the fifth embodiment similarly has a total of three positioning arches 15a, 15b, 15c that again perform the function of automatically positioning the stent 10 in the plane of the pulmonary valve or aortic valve. As in other embodiments of stent 10, the positioning arches 15a, 15b, 15c have a portion with a rounded head 20 that attaches to the pockets of the (inefficient) H heart valve for treatment when positioning the stent 10 at the implant site in the heart (see Fig. 12a).

[0126] A total of three retaining arches 16a, 16b, 16c and three attachment arches 19a, 19b, 19c are also provided.

[0127] The fifth embodiment of the stent 10 differs from the stent according to the third embodiment in that, in addition to the attachment holes 12, further cut-outs 26a are provided in the attachment part 11. As can be seen in Fig. 5d, a series of notches 26a are provided that serve as additional anchoring elements for the valve prosthesis 100 and guide the sewing thread or wire. These additional cut-outs 26a also minimize displacement of the sewing thread or wire, thereby reducing wear of the thread or wire by rubbing against the first connecting web 17 when the endoprosthesis 1 is implanted. Additional cuts 26a also ensure that the upper region of the valvular prosthesis can be attached tightly to the cardiac valve stent 10, allowing minimal displacement of the prosthesis which further minimizes the likelihood of wear caused by friction of sewing thread or wire.

[0128] It is of course possible that the additional cut-outs 26a are adapted to the thickness of the sewing thread or wire. In particular, additional cut-outs 26a may be rounded to minimize damage to the sewing thread or wire.

[0129] The fifth embodiment of the stent 10 also includes radial arches 32a, 32b, 32c extending from the positioning arches 15a, 15b, 15b towards the upper end 3 of the stent 10. As shown most clearly in Figs. 5a and 5b, stent 10 has three radial arches 32a, 32b, 32c, with each arc 32a, 32b, 32c sandwiched between two arms 15a, 15a ', 15b, 15b', 15c, 15c 'of each positioning arc 15a, 15b, 15c. Each radial arc 32a, 32b, 32c has a shape that is roughly inverse to each positioning arc 15a, 15b, 15c and extends in the opposite direction to each of the positioning arches 15a, 15b, 15c.

[0130] As can be seen especially in the notch pattern shown in Fig. 5d, each arm 32 ', 32 "of the radial arc 32 merges about the mid-point length of the stent 10 with the arm 15a', 15a", 15b ', 15b ", 15c ', 15c "of the opposite positioning arc 15a, 15b, 15c.

[0131] These two arms 32 ', 32 "of each radial arc 32a, 32b, 32c are connected together at the upper end 3 of the stent 10 by means of a rounded connecting part or head 33. This head 33 is not only rounded but also widens at tip so that the head 33 rests against the inner wall of the vessel on as large a contact surface as possible when the stent 10 is in its expanded and implanted state.

[0132] The heads 33 of each radial arc 32a, 32b, 32c also serve as additional means by which the stent 10 can be held in the catheter before and during implantation and / or to recover the stent after implantation.

[0133] Fig. 5c shows a perspective top view of the upper end 3 of the stent 10 and illustrates that the radial arches 32a, 32b, 32c are programmed so that they extend in a radial direction outside the perimeter of the stent 10 when the stent 10 is in its developed state. Thus, an increased pressure force can be applied to the vessel wall through the upper end region of the stent 10. This, in turn, allows increased security in attaching the stent 10 in place, thereby reducing the likelihood of stent migration. Thus, in the expanded state, in addition to the clamping effect of the positioning arches, the stent 10 according to the fifth embodiment is fixed at the implantation site by means of radial forces exerted by the holding arches 16a, 16b, 16c, auxiliary arches 18a, 18b, 18c and radial arches 32a , 32b, 32c, which all protrude outward in a radial direction from the perimeter of stent 10.

[0134] It can be seen from the notch pattern shown in Fig. 5d that the radial arches 32a, 32b, 32c do not protrude in the longitudinal direction L of the stent 10 beyond the plane in which the catheter retaining means 23 or the eyebolt fasteners are located 24. This ensures that the catheter retaining means 23 can mate with the respective components within the appropriate implantation catheter without interference from the heads 33 of radial arches 32a, 32b, 32c. Indeed, as explained above, the heads 33 as such can be used as additional catheter retaining means or additional means to perform the flattening of the stent 10.

[0135] In principle, the stent 10 may have more than three radial arches 32 to further increase the radial pressure. It is also possible to provide barb elements on all or some of the radial arches 32a, 32b, 32c, for example to allow even better anchoring of the stent 10 at the implantation site.

[0136] The stent 10 according to the sixth embodiment of the invention is shown in Figs. 6a-d and Figs. 6f-i. Figs. 6a-c show different perspective side views of the stent 10 in its expanded state, while a two-dimensional projection of the cutting pattern suitable for producing the stent according to the sixth embodiment is shown in Fig. 6d.

[0137] Fig. 6e shows a perspective side view of an endoprosthesis for treating a constricted cardiac valve or heart valve failure, wherein the endoprosthesis includes a cardiac valve stent that is similar to the sixth embodiment of the invention for supporting valve prosthesis. In detail, Fig. 6e shows the valve prosthesis 100 attached to the stent 10 an example of how to attach the valve prosthesis 100 to the stent 10. This example applies to the embodiments of the stent described herein.

[0138] Fig. 6f shows a perspective side view of an endoprosthesis for treating a constricted heart valve or heart valve failure, wherein the endoprosthesis comprises a heart valve stent according to a sixth embodiment of the invention for supporting a valve prosthesis.

[0139] Figs. 6g and 6h show different detailed perspective views of the endoprosthesis shown in Fig. 6f. Fig. 6i shows a top view of the lower end of the endoprosthesis shown in Fig. 6f;

[0140] As in the embodiments previously described, the stent 10 according to the sixth embodiment is again configured as a one-part structure cut from a part of the tube, especially a small metal tube, the cutting pattern is shown as a two-dimensional projection in Fig. 6d.

[0141] The sixth embodiment of the stent 10 is substantially similar in structure and function with respect to the fifth embodiment. To avoid repetition, reference is therefore made to the above description of the fifth embodiment. Especially radial arcs

32a, 32b, 32c, generally U or V-shaped, are also provided to increase the radially acting pressure force in the upper region of the stent 10.

[0142] The sixth embodiment differs from the fifth embodiment in that attachment bridges 27 with additional attachment parts 11a are provided for additional attachment of the valve prosthesis or valve prosthesis part. The presence of attachment bridges 27 with additional attachment parts 11a is particularly advantageous when a valve made of a sheet of biological material, such as pericardium, is used as a valve prosthesis, i.e. valve prosthesis, which is made of several parts of the material. When pericardial valves are used, care must be taken to ensure that the pericardial material can be securely attached to the stent 10. For this reason, the stent 10, according to the sixth embodiment, has a total of three attachment bridges 27, each of which includes additional attachment parts 11a . Each fastening bridge 27 is attached to one of the first connecting webs 17 and extends towards the lower end 2 of stent 10. [0143] Additional attachment parts 11a provided on attachment bridges 27 have even more attachment holes 12b and / or other attachment means, for example cutouts 26b, for anchoring threads or thin wire that are used to attach pericardial material or prosthesis valves for stent 10 allowing minimal, preferably no, displacement of the valve prosthesis. Of course, it is acceptable to provide mounting holes or mounting eyes whose diameter matches the thickness of the thread or wire used to secure the valve prosthesis. In general, the mounting holes 12b or cutouts 26b should be rounded to minimize wear of the thread or wire caused by friction as much as possible.

[0144] Reference should be made to Figs. 6e and 6f, which show a perspective side view of an endoprosthesis 1 for the treatment of narrowed heart valve or heart valve failure. In the embodiment depicted in Fig. 6f, the stent 10 corresponds to the stent according to the sixth embodiment of the invention for supporting valve prosthesis 100. The description of how the valvular prosthesis 100 is attached to the stent 10 with reference to the sixth embodiment is also applicable to the stent 10 according to the other embodiments described herein.

[0145] The valve prosthesis 100 includes at least one valve flap 102 (see Fig. 6h) made of biological or synthetic material. In particular, Fig. 6e shows a perspective side view of the endoprosthesis 1 with which the heart stent 10 is shown in a partially expanded state. Fig. 6f shows a perspective side view of the endoprosthesis 1 with which the heart stent 10 is shown in its fully expanded state. FIG. 6g-i show different detailed perspective views of the endoprosthesis 1 depicted in fig. 6f. More specifically, Fig. 6g is a detailed perspective view of a portion of the head 30 of the retaining arch 16a, and Fig. 6h is a detailed perspective view of the additional fastening portion 11a. Fig. 6i is a top view of the lower end 2 of the endoprosthesis 1 shown in Fig. 6f.

[0146] To ensure that minimal longitudinal displacement of the valve prosthesis 100 attached to the stent 10 can occur relative to the stent 10, even during peristaltic movement of the heart and blood vessel in which the stent 10 is used, the stent 10 according to the sixth embodiment of the invention comprises a plurality of fixation parts 11 extending in the longitudinal direction L of stent 10. Furthermore, the stent 100 according to the sixth embodiment is provided with additional fastening parts 11a, each of which is attached to one of the first connecting webs 17 and extends towards the lower end of the 2 stent 10. By means of both fastening parts 11 and additional parts fasteners 11a the valve prosthesis 100 is attached to the stent 10.

[0147] In detail, the valve prosthesis 100 is attached to the stent 10 by means of a thread 101 or a thin wire that is guided through each respective attachment hole 12, 12b, respectively, attachment parts 11 and additional attachment parts 11a. This enables the valve prosthesis 100 to be attached to the stent 10 at a predetermined position relative to the stent 10. By providing a plurality of attachment holes 12 for anchoring the valve prosthesis 100 to the stent 10, accurate positioning of the valve prosthesis 100 on the stent 10 is achieved.

[0148] Reference is here made to Fig. 6e, which shows an endoprosthesis 1 with a stent 10, which is a variant of the stent according to the sixth embodiment of the invention. The stent 10 shown in Fig. 6e is not yet fully developed. An endoprosthesis 1 with a fully developed stent 10 according to the sixth embodiment of the invention is shown in Fig. 6f.

[0149] The stent 10 of the invention is - as will be described in detail below with reference to the illustrations in Figs. 12a-c - shifted minimally invasively through the catheter insertion system either from the heart tip (i.e. transapical) or through the femoral artery and aortic arch (i.e. transfemoral) to the implant site in the heart. During the insertion procedure, the stent 10 with the prosthetic valve attached 100 is placed in the catheter system K tip in the collapsed state (cf. Fig. 12a). Upon reaching the implantation site in the heart, the stent 10 with the attached prosthetic valve 100 is sequentially released by selectively manipulating parts of the catheter's K tip. [0150] In detail, in the first release step, the catheter tip K of the catheter insertion system is manipulated such that the positioning arches 15a-c of the stent 10 are released, while the remaining parts of the stent 10, especially the retaining arches 16a-c, the auxiliary arches 18a these radial arches 32a-c are still in their folded state (cf. Fig. 12a). The positioning arches 15a-c released during the first release stage expand and spread radially outward. The expanded positioning arches 15a-c can then be inserted into the pockets T of the patient's native cardiac valve H by shifting the catheter K tip appropriately (cf. Fig. 12a).

[0151] In the second release step that follows, the catheter tip K of the catheter insertion system is operated so that the arches forming the lower end of the 2 stent 10 (auxiliary arches 18a-c holding arches 16a-c) are released when the upper end of the 3 stent 10 however, it is still firmly attached to the catheter tip K and is not released (see Figure 12b).

[0152] The positioning arches 15a-c disposed on stent 10 and also the holding arches 16a-c can be curved convex and arcuate in the proximal direction; i.e. towards the lower end 2 of stent 10, wherein such rounded forms may reduce arterial injury as well as facilitate disintegration during self-development. Such a design may allow for easier insertion of positioning arches 15a-c into the pockets of the native heart valve without injury to adjacent tissues and blood vessels, respectively. [0153] In Fig. 6e, the endoprosthesis 1 having the stent 10 according to one embodiment of the invention with the valve prosthesis 100 attached to the stent 10 is shown in a state after the second release stage in which only the upper end 3 with the catheter retaining means 23 is firmly connected to the tip K of the delivery system the catheter, while the remaining parts of the stent 10 have already been released and radially unfolded. This may result from the illustration in fig. 6e, due to self-expanding retaining arches 16a-auxiliary arches 18a-c, the valve prosthesis 100 attached to it is already unfolded (at least partially).

[0154] As shown in Fig. 6e, the distal portion of the stent 10 is still positioned in the sleeve-like portion P within the K-tip of the catheter. This case remains until the valve prosthesis 100 is unfolded and positioned to the extent that it can be checked for functionality.

[0155] If the functional test shows that the valve prosthesis 100 is working satisfactorily, the sleeve-like portion P may be, as shown in Figure 12c, distally pushed further in the proximal direction, so that also the distal portion of the stent 10 with the catheter retaining means 23 is completely released (see Fig. 12c).

[0156] It can further be seen from the illustration in Fig. 6e how the valve prosthesis 100 can be attached to the stent 10 by means of the thread 101. The pericardial valve prosthesis 100 is used in the illustrated embodiment which is sewn to the attachment holes 11a and 11b from fastening bridge 27, extending between two adjacent supporting arches 16a, 16b. See Fig. 6c and Fig. 6f. The valve prosthesis 100 may be substantially cylindrical with a substantially circular cross-section. At the lower end of stent 10, the valve prosthesis 100 has a lip 105. This lip 105, which is annular in plan view of the endoprosthesis 1, is formed by folding the lower end of the valve prosthesis 100 by curling it over itself. As shown in Fig. 6e, ring ring 105 is bound by thread 101. Ring ring 105 may have a different configuration.

[0157] The annular bar 105 at the lower end of the valvular prosthesis 100 can provide secure anchoring to the peripheral region of the valvular prosthesis 100 to the blood vessel in the implanted state of the endoprosthesis 1, even with peristaltic movement, and therefore can provide secure sealing against the vessel wall.

[0158] The annular ring 105 can achieve secure sealing of the valve prosthesis 100 in the vessel wall despite the basic triangular structure of the stent 10 in the top view of the developed endoprosthesis 1. After implantation of the endoprosthesis 1 in the native blood vessel, any leakage between the peripheral area of ​​the annular strip 105 and the vessel wall it is sealed by naturally occurring accretion, especially calcification. Accordingly, the bar-shaped surface 105 provides a secure seal, especially also during the filling phase of the heart cycle (diastole).

[0159] Fig. 6i also shows a top view of the lower end 2 of the endoprosthesis 1 illustrated for example in Fig. 6f, where the stent 10 for the endoprosthesis 1 is shown in its fully developed state.

[0160] As shown in Fig. 6i, the segments 102 of the valve prosthesis valves 100 are closed in a top view according to Fig. 6i, as is the case during diastole of the heart.

[0161] As shown in detail in Figs. 6f and 6g, the attachment bridges 27 with the additional attachment parts 11a also have cutouts 26b for anchoring the thread or thin wire that are used to attach the pericardial material or prosthesis 100 to the stent 10 to allow minimal, preferably no, displacement of the valve prosthesis. In addition, auxiliary arches 18a-c are used as fasteners for anchoring the valve prosthesis 100 to the stent 10.

[0162] It can also be seen from Figures 6f and 6g that the lower part of the valve prosthesis 100 is turned inside out so as to form a peripheral flap in which the individual parts of the heads 30 'of the arches securing 19a are attached heads 31 auxiliary arches 18a-c. The valve prosthesis 100 is therefore attached to the stent 10 with minimal mobility so that relative displacement between stent 10 and the valve prosthesis 100 due to peristaltic movement of the heart after implantation of the endoprosthesis 1 can be effectively prevented.

[0163] A seventh embodiment of the stent 10 according to the invention will be described below with reference to Figs. 7a-c. Here, Figs. 7b and 7c each show perspective side views of a fully developed stent 10, while Fig. 7a shows a two-dimensional projection of the notch pattern used in the manufacture of a heart valve stent according to the seventh embodiment of the invention to allow the heart valve stent according to e.g. Figure 7b or FIG. 7c be integrally cut from a tube section, especially a small metal tube.

[0164] In addition to the lower end section, the stent 10 according to the seventh embodiment substantially corresponds to the stent according to the sixth embodiment of the invention described above with reference to Figs. 6a-d and Figs. 6f-i.

[0165] Hence, the stent 10 according to the seventh embodiment also has a total of three positioning arches 15a, 15b, 15c that again perform the function of automatically positioning the stent 10 in the pulmonary or aortic valve plane. As with other embodiments of stent 10, the positioning arches 15a, 15b, 15c have a portion with a rounded head 20 that attaches to the pockets of the (inefficient) H heart valve for treatment when positioning the stent 10 at the implantation site in the heart (see Fig. 12a).

[0166] A total of three retaining arches 16a, 16b, 16c and three attachment arches 19a, 19b, 19c are also provided.

[0167] Also, attachment bridges 27 with additional attachment parts 11a are provided for additional attachment of the valve prosthesis or valve prosthesis part. Each fastening bridge 27 is attached to one of the first connecting webs 17 and extends towards the lower end 2 of stent 10. Additional attachment parts 11a provided on attachment bridges 27 have even more attachment holes 12b and notches 26b for anchoring thread or thin wire that are used to attach pericardial material or prosthetic valve to stent 10 allowing minimal, preferably no, displacement valve prostheses. It is of course acceptable that the provision of attachment holes or attachment eyes whose diameter is matched to the thickness of the thread or wire used to secure the valve prosthesis.

[0168] The seventh embodiment of the stent 10 also includes radial arches 32a, 32b, 32c extending from the positioning arches 15a, 15b, 15b towards the upper end 3 of the stent 10. As shown most clearly in FIGS. 7b and 7c, stent 10 has three radial arches 32a, 32b, 32c, with each arc 32a, 32b, 32c positioned between two arms 15a, 15a ', 15b, 15b', 15c, 15c 'of each positioning arc 15a, 15b, 15c. Each radial arc 32a, 32b, 32c has a shape that is roughly inverse to each positioning arc 15a, 15b, 15c and extends in the opposite direction to each of the positioning arches 15a, 15b, 15c.

[0169] Because in the implanted state of the endoprosthesis 1, the valve prosthesis 100, during the filling phase of the heart cycle (diastole), there are significant forces that are transmitted to the stent attached to the valve prosthesis 100, secure anchoring of the stent 10 with the valve 100 attached implant site may be of particular importance. The seventh to eleventh embodiments of the stent 10 described below include further measures that can be provided in addition to the above described embodiments of the retaining arches, auxiliary arches and radial arches, which can more securely anchor stent 10, endoprosthesis 1 at the implant site, and which can prevent positional displacement of the endoprosthesis 1.

[0170] In detail, at least one annular flange 40 is provided that forms the lower end 2 of the stent 10 according to the seventh embodiment as an additional anchoring means for the stent 10 depicted in Figs. 7a-c. This annular flange 40 can be connected to each or part of the lower end sections of the respective retaining arms 16a ', 16a ", 16b', 16b", 16c ', 16c "of the retaining arches 16a and the lower end sections of the respective arms 19a', 19a ", 19b ', 19b", 19c', 19c "fastening arches 19a-c, as can be seen especially from the cutting pattern according to Fig. 7a. Also, the lower end sections of the respective arms 18a ', 18a ", 18b', 18b", 18c ', 18c "auxiliary arches 18a, 18b 18c may be connected to the annular flange 40.

[0171] The annular flange 40 has a plurality of support ribbons 41, which run parallel to the longitudinal axis of the stent 10 in the unfolded state of the stent 10 and are connected to each other by transverse ribbons 42 (cf. Fig. 7a). In the expanded state of the stent 10, the support ribbons 41 and the transverse ribbons 42 form a serrated, rhomboidal or serpentine annular collar 40 that adheres to the vessel wall in the implanted state of the endoprosthesis 1, stent 10, respectively. 7b and 7c show the annular flange 40 in the expanded state.

[0172] The annular flange 40 serves as a supporting body through which the radial forces, developing through self-expansion, are transferred to the vessel wall.

Because the relatively large contact surface of the stent 10 acts on the vessel wall, and because of the toothed, rhomboidal or serpentine structure to the annular flange 40, the risk of damage to the artery or tissue can be reduced despite increased radial forces.

[0173] Accordingly, not only the stiffness of the stent 10 can be increased after self-expansion by providing the annular flange 40, but also the anchoring of the stent 10 in the implanted state can be improved or strengthened. In addition, the shape of the annular cross-section to the annular flange 40 increases the seal between the vessel wall and the endoprosthesis 1.

[0174] Such annular flange 40 is preferably configured as a self-expanding support structure that positively affects the even improved anchorage of the stent 10 at the implant site due to its radially outward contact pressure and its design that can be further prevented shifting or rotating the stent 10 with the valve prosthesis 100.

[0175] An eighth embodiment of the stent 10 according to the invention is shown in Figs. 8a-c. In detail, FIGS. 8b and 8c each show the stent 10 according to the eighth embodiment in a side perspective view, with the stent 10 fully unfolded. Fig. 8a shows a two-dimensional projection of a cutting pattern for use in producing a cardiac valve stent according to an eighth embodiment of the invention for cutting a cardiac valve stent according to Fig. 8b or Fig. 8c integrally with a part of the tube, especially a small metal tube.

[0176] In addition to the upper end section, the stent 10 of the eighth embodiment essentially corresponds to the stent of the fifth embodiment of the invention described above with reference to Figs. 5a-d.

[0177] Hence, the stent 10 of the eighth embodiment likewise has a total of three positioning arches 15a, 15b, 15c that again perform the function of automatically positioning the stent 10 in the plane of the pulmonary valve or aortic valve. As with other stent 10 embodiments, the positioning arches 15a, 15b, 15c have a portion with a rounded head 20 that is secured in the pockets of the (inefficient) heart valve H for treatment when positioning the stent 10 at the implantation site in the heart (see Fig. 12a ).

[0178] A total of three retaining arches 16a, 16b, 16c and three attachment arches 19a, 19b, 19c are also provided.

[0179] Furthermore, in the eighth embodiment of the stent 10, further cutouts 26a are provided, in addition to the attachment holes 12 in the attachment portion 11, which serve as additional anchoring means for valve prosthesis 100 and guides for sewing thread or wire. These additional cutouts 26a also minimize displacement of the sewing thread or wire, thereby reducing the wear of the thread or wire by rubbing against the first connecting web 17 when the endoprosthesis 1 is implanted. Additional cutouts 26a also ensure that the upper area of ​​the valvular prosthesis can be attached tightly to the cardiac valve stent 10, allowing minimal displacement of the prosthesis thereby further minimizing the likelihood of wear caused by friction of sewing thread or wire.

[0180] A total of three retaining arches 16a, 16b, 16c and three attachment arches 19a, 19b, 19c are also provided.

[0181] Unlike the seventh embodiment (cf. Figs. 7a-c), however, the lower (proximal) end 2 of stent 10 remains unchanged in the eighth embodiment, while the upper annular collar 40 'is formed in the upper (distal) end 3 of the stent 10. As shown in Figures 8b and 8c, the annular flange 40 'is made of support webs 41 and crossbands 42 and forms a diamond-shaped support structure in its expanded state.

[0182] From the illustration of the cutting pattern according to Fig. 8a, it can be seen that the upper annular flange 40 'used in the eighth embodiment is attached to the upper parts of the radial arc heads 32a, 32b, 32c. On the other hand, the upper annular flange 40 'is attached to the second connecting web 25 so that it is spaced from the plane in which the means 23 for holding the catheter in the expanded state are arranged (see Figs. 8b, 8c). Specifically, the annular flange 40 'in the eighth embodiment is disposed between the plane in which the catheter retaining means 23 lies and the plane in which the connecting portion 22 of two arms adjacent the positioning arches 15a-c lies. Up to this end, the connecting web 25 is configured as slightly longer compared to the connecting web in the fifth embodiment.

[0183] Since the upper annular flange 40 'used in the eighth embodiment is comparable to the lower annular flange 40 used in the seventh embodiment in terms of function, it is not further described for the purposes of explanation.

[0184] Reference will now be made to Figs. 9a and 9b in the description of the ninth embodiment of the stent 10 according to the invention. Fig. 9b thus shows a perspective view of the stent 10 in its expanded state. Fig. 9a shows a two-dimensional projection of a cutting pattern for use in the manufacture of a cardiac valve stent according to the ninth embodiment of the invention for cutting a cardiac valve stent according to Fig. 9b integrally from a portion of a tube, especially a small metal tube;

[0185] Since the upper annular collar 40 'is also formed at the upper end 3 of the stent 10, the stent 10 according to the ninth embodiment is similar to the previously described stent according to figures 8a-c (eighth embodiment). In contrast to the eighth embodiment, the upper annular flange 40 'in the ninth embodiment is configured to be longer in the longitudinal direction of the stent 10. Specifically, a comparison of Fig. 9b and Fig. 8b shows that in the ninth embodiment, two annular diamond bodies lying on top of each other are used as a 40 'annular flange. This can increase the radial pressure force that the stent 10 exerts from its upper end 3. The correspondingly elongated connecting web 25 is again used in the embodiment of Figs. 9a-b.

[0186] Fig. 10 shows a two-dimensional projection of an excision pattern that can be used to exclude a cardiac valve stent 10 according to the tenth embodiment of the invention as one integral element from a portion of the tube, especially a small metal tube.

[0187] As well as with the eighth embodiment described above with reference to Figures 9a-b and the ninth embodiment described above with reference to Figures 8a-b, the tenth embodiment of the stent 10 according to the invention substantially corresponds to the embodiment described with reference to Figures 5a-d.

[0188] In contrast, for example, to the eighth embodiment (cf. Figs. 8a-c), however, the upper (distal) end 3 of the stent 10 remains unchanged in the tenth embodiment, while the lower annular flange 40 is formed in the lower ( proximal) end 2 of the stent 10. As shown in Fig. 10, the annular (lower) flange 40 is also constructed of support webs 41 and crossbands 42 and forms a diamond-shaped support structure in its expanded state.

[0189] From the illustration of the cutting pattern according to Fig. 10, it can be seen that the lower annular flange 40 used in the tenth embodiment is connected to the lower parts of the heads of the retaining arches 16a, 16b, 16c, the securing arches 19a, 19b, 19c and the auxiliary arches 18a , 18b, 18c. On the other hand, the lower annular flange 40 is attached to the retaining arches 16a, 16b, 16c, retaining arches 19a, 19b, 19c and auxiliary arches 18a, 18b, 18c so that it is arranged at a distance from the plane in which the catheter retaining means 23 is in the expanded state.

[0190] Since the lower annular flange 40 used in the tenth embodiment is comparable to the lower annular flange 40 used in the seventh embodiment in terms of function, it is not further described for the purposes of explanation.

[0191] Fig. 11 shows a two-dimensional projection of a cutting pattern that can be used to cut a cardiac valve stent 10 according to the eleventh embodiment of the invention as one integral element from a portion of the tube, especially a small metal tube.

[0192] In addition to the upper end section, the stent 10 of the eleventh embodiment is similar to the stent of the fifth embodiment of the invention described above with reference to Figs. 5a-d.

[0193] Hence, the stent 10 according to the eleventh embodiment also has a total of three positioning arches 15a, 15b, 15c that again assume the function of automatically positioning the stent 10 in the plane of the valve, pulmonary valve or aortic valve. As with other embodiments of the stent 10, the positioning arches 15a, 15b, 15c have a portion with a rounded head 20 that attaches in the pockets of the (inefficient) heart valve H for treatment when positioning the stent 10 at the implantation site in the heart (see Fig. 12a ).

[0194] A total of three retaining arches 16a, 16b, 16c and three attachment arches 19a, 19b, 19c are also provided.

[0195] The eleventh embodiment of the stent 10 also includes radial arches 32a, 32b, 32c extending from the positioning arches 15a, 15b, 15c towards the upper end 3 of the stent 10. As shown in Figure 11, the stent 10 has three radial arches 32a, 32b, 32c, with each arc 32a, 32b, 32c positioned between two arms 15a, 15a ', 15b, 15b', 15c, 15c 'of each positioning arc 15a, 15b, 15c. Each radial arc 32a, 32b, 32c has a shape that is roughly inverse to each positioning arc 15a, 15b, 15c and extends in the opposite direction to each of the positioning arches 15a, 15b, 15c.

[0196] The eleventh embodiment of the stent (cf. Fig. 11) differs from the fifth embodiment of the invention described above with reference to Figs. 5a-d in that two annular flanges 40, 40 'are provided that form the upper and lower the ends 2, 2 'of the stent 10 according to the eleventh embodiment as an additional anchoring means for the stent 10. As in the seventh embodiment described above with reference to Fig. 7a-c, the lower annular flange 40 may be attached to the lower end sections of the respective holding arms 16a ', 16a ", 16b', 16b", 16c ', 16c "arches holding the 16a-lower bottom sections of the respective arms 19a', 19a" , 19b ', 19b ", 19c', 19c" fastening arches 19a-c, as can be seen especially from the cutting pattern according to Fig. 11. On the other hand, the upper annular flange 40 'used in the eleventh embodiment is attached to the upper parts of the radial arc heads 32a, 32b, 32c. More specifically, the annular flange 40 'in the eleventh embodiment is disposed between the plane in which the catheter retaining means 23 lies and the plane in which the connecting portion 22 of the two arms adjacent the positioning arches 15a-c lies.

[0197] As already described with reference to the seventh to the tenth embodiment according to the invention, the upper and lower annular flanges 40, 40 'have a plurality of support webs 41 that run parallel to the longitudinal axis of the stent 10 in the unmounted state of the stent 10 and are with each other joined by crossbands 42 (see Figure 11). Again, in the expanded state of the stent 10, the supporting webs 41 and the transverse webs 42 form serrated, rhomboid or serpentine ring flanges 40, 40 'that adhere to the vessel wall in the implanted state of the endoprosthesis 1, stent 10, respectively.

[0198] Comparison of Fig. 11 with the cutting patterns according to Figs. 8a and 9a shows that the stent 10 according to the eleventh embodiment according to the invention essentially passes from the stent 10 according to the eighth embodiment (cf. Figs. 8a-c), but for better Anchored, an additional (bottom) ring flange 40 is formed at the bottom end of the 2 stent 10. This additional lower annular collar essentially corresponds to the lower annular collar used in the seventh embodiment (cf. Figs. 7a-c). To avoid repetition, refer to the previous comments regarding the seventh and eighth embodiment.

[0199] Naturally, the annular collar 40 or 40 'may in principle also be located in the plane in which the valve prosthesis is placed. Furthermore, it is not necessary for the annular flange 40 to connect to all end sections respectively the retaining arches 16a-c or the auxiliary retaining arches 19a-c. The upper ring flange 40 'need not necessarily be connected to all end sections of the radial arches 32.

[0200] Stent 10 is preferably made of shape memory material. The condition of the stent 10 shown in Fig. 1a or Fig. 2a, in which the stent 10 is in its first state, thus in its collapsed state, is the so-called "temporary" shape of the stent structure made of shape memory material. When the external stimulus acts on the structure of the stent according to Fig. 1a or Fig. 2a, the shape memory effect is activated and thus the predetermined solid shape recorded during the production of the stent 10, e.g. according to Fig. 1b or Fig. 2b, is restored.

[0201] This external stimulus is preferably a defined switching temperature, wherein to activate the shape memory effect and thereby regenerate the saved shape of the permanent stent 10, the stent material is heated to a temperature higher than the switching temperature. By choosing the appropriate chemical composition of the material for stent 10, a particular switching temperature can be predetermined. In a preferred embodiment of the solution of the invention, the switching temperature ranges from between about 20 ° C and the patient's body temperature.

[0202] After implantation of the stent 10, it is acceptable that the stent 10 will be cooled during the insertion procedure. After directing the stent 10 to the desired implantation site, i.e. to the native H valve (see Fig. 12a), preferably using an appropriate catheter insertion system, cooling can be stopped. The stent 10 is then allowed to warm to the patient's body temperature (36 ° C) and the stent material shape memory effect is thus activated. Due to the triggering of the self-expanding properties of stent 10, radial forces are generated that act on individual components of the stent, especially on positioning arches 15a, 15b, 15c, holding arches 16a, 16b, 16c and auxiliary arches 18a, 18b, 18c stent 10.

[0203] The stent 10 of the invention, as well as the catheter insertion system used to implant the stent, are preferably configured so that the stent 10 with the attached prosthetic valve 100 can be introduced through the arteries into the patient's body. In one example, the stent 10 is located at the catheter tip of the catheter insertion system, the catheter tip is inserted into the body, for example, by puncture of A. femoris communis (inguinal artery). A suitable catheter system is described in WO2006 / 076890 and PCT / EP2008 / 003803.

[0204] Alternatively, the stent 10 according to some embodiments of the invention is also suitable for transabdominal implantation, in which - from the tip of the heart - the catheter tip of the catheter insertion system is moved to the aortic valve, for example through the left ventricle. With the help of a suitably modified catheter tip, analogous implantation of stent 10 with valve prosthesis 100 is therefore possible. A suitable catheter system is described in PCT / EP2008 / 003803.

[0205] Regardless of whether the stent 10 is delivered to the implantation site via an arterial or transbranch approach, the catheter tip of the catheter insertion system is preferably moved to the implantation site using angiographic (angiography) and echocardiographic (ultrasonic) control. This is followed by actual implantation of the stent 10 with the valve prosthesis 100 attached.

[0206] Figs. 12a to 12c schematically show a sequence of processes to illustrate the arterial implantation of an endoprosthesis 1 comprising a stent 10 according to some embodiments of the invention. As shown, the implantation of the stent 10 with the valve prosthesis 100 attached occurs in such a way that the individual components of the stent 10 positioned in the catheter tip K are successively released by appropriate guiding of the catheter tip K of the catheter insertion system.

[0207] The catheter system used for implanting the stent 10 of the invention is ideally configured so that liquid coolant can be fed through the empty interior of the catheter system to the catheter tip K. The liquid coolant, for example in the form of a physiological saline solution, supports the stent 10 placed in the catheter tip K at a temperature below the switching temperature, while the catheter tip K is moved to the implantation site. This is particularly advantageous when a shape memory material is provided as is the material of the stent 10. This is because the stent 10 transforms from a temporary shape to a permanent shape upon the influence of an external stimulus. The temporary shape is the first shape of the stent 10 (in the collapsed state when the stent 10 is positioned at the K tip of the delivery system catheter) and the "permanent shape" is the second shape of the stent 10 (expanded state of stent 10 after releasing the stent 10 from the K tip of the catheter).

[0208] It should be noted that the "permanent shape" of the expanded stent 10 corresponds to the native shape of its environment. This allows changes in the shape of the environment at the implantation site, which will vary from patient to patient. This property of the stent 10, associated with the "permanent shape" of the expanded stent 10, automatically adapting completely to the native shape of its environment, will therefore always ensure that the valve prosthesis 100 is implanted optimally.

[0209] Since a shape memory material such as nitinol, i.e. an equimolar alloy of nickel and titanium, can be applied to the stent 10 of the invention, a particularly gentle implantation procedure is achievable when implanting the stent 10 with the valve prosthesis 100 attached.

[0210] The stent 10 disposed in the catheter tip K may be cooled by flushing the catheter insertion system with a suitable coolant while the catheter tip K is moved to maintain the stent material temperature below the critical transition temperature. When the catheter tip K with the cooled stent 10 has been moved to the implantation site, cooling of the stent 10 should be stopped, as a result of which the stent 10 heats up to the patient's body temperature (36 ° C) and the shape memory effect of the stent material is therefore activated.

[0211] As soon as the self-expansion property of the individual elements of the stent 10 has been activated, radial forces are generated, which acts on the individual elements of the stent 10, especially on the positioning arches 15a, 15b, 15c, holding arches 16a, 16b, 16c and auxiliary arches 18a, 18b, 18c stent 10. Because the respective components of the stent 10 are still located at the K-tip of the catheter, the radial forces created by the critical switch-on temperature are lengthened and the operating individual components of the stent 10 are still compensated by the wall by the K-tip of the catheter so that despite activating the shape memory effect - the stent 10 is kept in its first (rolled) shape by force.

[0212] By subsequent manipulation of the catheter's K tip - by appropriate increasing release of the stent 10 - the individual components of the stent 10 are then removed from the catheter's K tip. As shown in Fig. 12a, the positioning arches 15a, 15b, 15c of the stent 10 expand radially by the action of radial forces. The expanded positioning arches 15a, 15b, 15c can then be positioned into the pockets T of the native heart valve H.

[0213] From now on - as shown in Figure 12b - the remaining components of the stent 10 are sequentially released from the catheter tip K. The remaining components of the stent 10 are released, especially the auxiliary arches 18a, 18b, 18c and retaining arches 16a, 16b, 16c with the valve prosthesis 100, then radially flared and the valve prosthesis 100 attached to the mounting parts 11 unfolds like an umbrella.

[0214] Radial forces act on both retaining arches 16a, 16b, 16c and auxiliary arches 18a, 18b, 18c of stent 10, as well as as radial forces acting in the upper region 3 of stent 10, resulting in pressing the stent radially to the vascular wall (cf. Fig. 12c). This affects the secure anchorage of the stent 10 with the developed prosthesis 100 of the implant site on one side, and on the other hand the reliable sealing of the prosthesis valve 100 at the lower end of the 2 stent 10.

[0215] The catheter tip K of the catheter insertion system is then further maneuvered to extend the eyes 24 of the stent 10, while allowing the area 3 of the stent 10 to expand. In doing so, the valve leaflets, the native H heart valve, are stretched between the respective positioning and retaining arches and the valve prosthesis 100, located at the lower end of the 2 stent 10, can expand.

[0216] After successful implantation of the stent 10 and valve prosthesis 100, the catheter is then removed from the patient.

[0217] Stent 10 is not limited to making it from a shape memory material that itself expands from its first (rolled up) shape to its second (expanded) shape in response to an external stimulus. Rather, the stent 10 is categorically conceivable using a conventional balloon system.

[0218] It will be appreciated that the method of the invention is not limited to the specific embodiments as described with reference to the attached drawing. Rather, the invention includes combinations of the individual features listed in the described embodiments.

[0219] Regarding the attachment of the upper area 3 of the stent 10 to the wall of the blood vessel in which the stent 10 is placed, it would be conceivable for the stent 10 to include spaced spike elements, for example on the eyelets 24, the spike peaks toward the lower end 2 of the stent 10.

[0220] In addition, an insert or sheath, typically a fabric, polymer or pericardial sheet, membrane, or the like may be provided over at least the outer portion of the stent 10 to cover all or most of the outer surface of the stent 10 protruding from a near-proximal location to a near - remote location. The insert may be attached to the stent 10 at at least one end, as well as at multiple locations between these ends, thereby forming an outer covering. This outer covering provides a peripheral seal on the inner wall of the lumen of the blood vessel to thereby inhibit leakage of blood flow between the stent 10 and the lumen wall and to prevent blood flow from bypassing the endoprosthesis 1.

[0221] For example, the insert may be sewn or otherwise attached to the stent 10 along a plurality of circumferentially separated axial lines. This attachment allows the insert to fold along a plurality of axial fold lines when the stent 10 is radially compressed. The insert will also be able to open and adapt to the wall from the light side of the tubular frame as the frame unfolds. Alternatively, the insert may be heat-welded or ultrasonically welded to the stent 10. In the exemplary embodiment where the stent 10 is provided with a plurality of independent attachment parts 11, 11a, the insert may be attached to these attachment parts 11, 11a. In the second exemplary embodiment, where multiple independent arches are provided (positioning arches 15a, 15b, 15c, holding arches 16a, 16b, 16c, auxiliary arches 18a, 18b, 18c and / or mounting arches 19, 19a, 19b, 19c) the insert is attached to these arches preferably along axial lines. The insert will preferably be circumferentially welded on the stent 10 at at least one end.

[0222] By covering at least a portion of the outer surface of the stent 10 with an insert or sheath, the thrombogenicity of the endoprosthesis 1 resulting from the exposure of the stent component is greatly reduced or eliminated. This reduction in thrombogenicity is achieved while maintaining the benefit of the stent structure that is used to develop the valve prosthesis 100 and to anchor the valve prosthesis 100 in place.

[0223] As already mentioned, the stent 10 can be compressed from the expanded large diameter configuration to the small diameter configuration to facilitate insertion. Of course, it is necessary that the outer insert remains attached to the stent 10 both in its radially compressed configuration and in its expanded, expanded configuration.

[0224] The insert is composed of pericardial material or conventional biological implant materials, such as polyesters, polytetrafluoroethylenes (PTFE's), polyurethanes and the like, usually being in the form of woven fabrics, non-woven fabrics, polymeric sheets, membranes and the like. Currently, the preferred fabric insert material is plain woven polyester, such as Dacron® fiber (Dupont, Wilmington, Delaware).

List of reference numbers [0225] endoprosthesis lower end of the stent / endoprosthesis upper end of the stent / endoprosthesis stent cardiac valve / stent fastening part of the stent 11 additional fastening part of the stent fastening holes 12 additional fastening holes 12b auxiliary fastening holes upper end fastening part lower end fastening part 15a-15c positioning arches

15a'-15a "arms of the first positioning arc 15b'-15b" arms of the second positioning arc 15c'-15c "arms of the third positioning arc 16a-16c holding arches

16a'-16a "arms of the first holding arch 16b'-16b" arms of the second holding arch 16c'-16c "arms of the third holding arch 17 first connecting web

17 the upper end of the first connecting web 17 the bottom end of the first connecting web 18a-18c auxiliary arches

18a'-18a "arms of the first auxiliary arch 18b'-18b" arms of the second auxiliary arch 18c'-18c "arms of the third auxiliary arch 19, 19a-19c fastening arches

19a'-19a "arms of the first securing arch 19b'-19b" arms of the second securing arch 19c'-10c "arms of the third arch securing the part of the arch head positioning the reference marker the connecting part between the arms of adjacent arches positioning means securing the second eye catheter ribbon connecting notches

26 additional notches

26 auxiliary bridges connecting the head part / connecting part of the holding arch

30 'head part / connecting part of the bow securing head part / connecting part of the auxiliary bow

32a-32c radial bends head / connecting part of a radial bend an annular flange

40 'upper collar annular web supporting transverse band

100 valve prosthesis

101nić

102 lobe segment of the valve prosthesis

105 Valve ring prosthesis

H native heart valve

K catheter tip of the catheter insertion system

L longitudinal direction of the stent

T native heart valve pocket

P sleeve-like valve prosthesis