Device for implanting and fastening heart valve prostheses

ES 2 355 583 T3

DESCRIPTION

The present invention relates to a device for the transvascular implantation and fixation of heart valve prostheses, with an expandable heart valve stent that presents a heart valve prosthesis at its proximal end.

Such a device is known in principle from the medical art. Models of biological or mechanical valves are now available for the replacement of human heart valves, which are usually sewn into the heart valve bed after surgical removal of the diseased heart valve, through a hole in the heart valve. rib cage. For this intervention, it is necessary to support the patient's circulation by means of a heart-lung machine, inducing cardiac arrest during implantation of the heart valve prosthesis. It is a high-risk surgical procedure with corresponding dangers for the patient and a long postoperative treatment phase. In particular, an intervention of this kind can no longer be performed in patients with heart failure.

Very recently, minimally invasive therapy procedures have been developed, which are particularly characterized in that only a remarkably reduced anesthesia time is already required for the intervention. In one approach, it is envisaged to implant in the human body a self-expanding heart valve prosthesis with an artificial heart valve and with a collapsible and expandable stent connected to the heart valve, by means of the corresponding catheter system. Such a self-expanding heart valve prosthesis can be guided by a catheter system to the implantation site in the heart, via an inguinal artery or vein. Once the implantation site has been reached, the stent can be successively deployed, which in its longitudinal direction is composed, for example, of several self-expanding stent segments bent relative to one another. After deployment, the heart valve prosthesis can be anchored in the corresponding blood vessel, for example using anchoring hooks, at least in the area close to the heart. The heart valve prosthesis itself is located in the direct vicinity of the stent for this purpose.

The publication DE 100 10 074 A1 discloses, for example, a device for fixing and anchoring prosthetic heart valves, which essentially consists of wire-shaped elements connected to one another. In this case, it is envisaged that different stirrups are used to achieve secure fixation and support of the heart valve prosthesis. The device described in this publication uses for this purpose three pairs equal to each other of stirrups, arranged respectively with a spacing of 120 ° from each other. These stirrups are connected to each other by means of solid joints, the solid joints fulfilling the function of rotation bearings. Additionally, there are stirrups bent in the opposite direction that form lever arms, ideally of equal length, in order to achieve a secure seat of the stirrups even during peristaltic movements in the heart and in the blood vessel as well as a secure sealing of the an implanted and fixed heart valve prosthesis.

The closest state of the art is that disclosed in the publication WO2005 / 062980, which refers to a heart valve prosthesis composed of a position stent and a heart valve stent, the stent of the heart valve being not expandable. heart valve.

Publication WO 2006/127756, which according to Art. 54 (3) EPÜ has to be taken into account for the character of novelty, discloses a heart valve prosthesis composed of a position stent and a heart valve stent , the stent of the heart valve being expandable.

In known solutions, however, there is a risk of an implantation error of the heart valves. This primarily refers to the exact angular position and orientation of the heart valve prosthesis to be implanted. In particular, it is only possible with great operator skill, if at all, to position a stent having the prosthesis of the heart valve at its proximal end, with such precision in the vicinity of the diseased heart valve of the patient that Both a sufficient lateral position accuracy as well as an optimal suitable angular position of the heart valve prosthesis can be ensured. Known solutions are also only conditionally suitable for re-explanting heart valve prostheses that are not positioned correctly or are incorrectly positioned; this can usually only be done with great complexity, and in particular another operative intervention is required for this.

An erroneous implantation of a heart valve prosthesis that is not optimally positioned, for example, can lead, among other things, to valve leakage or insufficiency, which entails considerable loads on the ventricle. If, for example, a heart valve implantation is carried out too far above the plane of the heart valve itself, it can lead to the closure of the coronary outlets, and thus to a fatal coronary ischemia with heart infarction. It is therefore absolutely necessary that both the lateral position accuracy and also the angular position of an implanted heart valve prosthesis meet the requirements.

ES 2 355 583 T3

In conventional implantation techniques in which self-expanding heart valve prostheses are conducted, for example through an inguinal artery of the patient, minimally invasively to the implantation site in the heart, the insertion of the prosthesis is generally performed by a guide wire and using catheters, for which conventional balloon catheters can also be used. Although in such an intervention the introduction can be monitored and controlled for example by fluoroscopy (cardiac catheter laboratory = HKL) or using ultrasound (transesophageal echocardiogram = TEE), it is often not possible to ensure the necessary precision of position and in particular the angular position of the prosthesis of the heart valve to be implanted with the corresponding fixation elements attached to it, due to the limited maneuverability of the heart valve prosthesis which is still folded during the insertion process, and which, despite its folded state, has relatively large dimensions. In particular, an angular dislocation of the implanted heart valve prosthesis from the optimal implantation site may represent a risk for the respective patient, due to a possible obstruction of the coronary vessels.

During the design of the heart valve prosthesis, the considerable forces acting on the prosthesis during the filling phase of the cardiac cycle (diastole) must also be taken into account in particular, whereby a secure anchorage is required in order to prevent detachment of the implanted heart valve prosthesis.

For this reason, it is necessary that, on the one hand, the prosthesis of the heart valve can be maneuvered as well as possible during the implantation process in the corresponding coronary vessel in order to ensure in this way an optimal positional precision, and on the other hand it is It is necessary that the implanted prosthesis can be firmly anchored in its implantation site in order to effectively prevent further dislocation of the prosthesis.

The present invention starts from the problem that known devices for transvascular implantation and fixation of prosthetic heart valves are often not suitable for simply implanting with the necessary positional precision a prosthetic heart valve in a ventricle of the heart of a patient. In particular the necessary lateral position accuracy and the angular position of the heart valve prosthesis can generally only be sufficiently ensured if the operator has corresponding experience. On the other hand, until now it was only possible with great difficulty, if at all, to explant an already implanted heart valve prosthesis by minimally invasive intervention, or to properly correct a defectively positioned heart valve prosthesis.

Starting from this problem, the present invention sets the objective of describing a device that allows a heart valve prosthesis to be implanted in the simplest way possible in a patient with a minimal invasive intervention, where a superior precision of position of the the prosthesis in the ventricle of the patient's heart. In particular, the aim is to reduce as much as possible the risk of performing a defective implantation by means of a device of this kind.

According to the invention, this objective is solved by a device according to claim 1.

The device according to the invention has a whole series of essential advantages over the heart valve prostheses known from the state of the art and described above. Due to the design of the device in two parts, in the form of the heart valve stent and the positioning stent produced independently of the latter, the positioning precision of the heart valve prosthesis in the ventricle of the heart can be notably increased in particular. of the patient. In this case, the positioning stent first assumes the function of determining the position of the heart valve prosthesis in the ventricle of the patient's heart as well as the function of anchoring or fixing the prosthesis in its implantation site. optimal. The heart valve prosthesis is not made in particular on the positioning stent but on the heart valve stent produced independently of the positioning stent. This has the advantage that the dimension of the positional stent in the folded state is extremely small, which increases the maneuverability of the stent.

In the device according to the invention, the heart valve stent serves primarily only as a supporting structure for the heart valve prosthesis to be implanted. Through this division of functions, it is possible to make both the positioning stent and the heart valve stent relatively simple. In particular, it can be achieved that compared to a stent in which not only a heart valve prosthesis but also the means for positioning and fixing the heart valve prosthesis are arranged, the positioning stent present in its folded state only relatively small dimensions. Insertion of the positioning stent into the patient's artery is therefore considerably easier, due to the better maneuverability thus achieved. The direct consequence of this is a higher positioning accuracy of the positioning stent.

The device according to the invention is designed in such a way that only after the positioning stent has been introduced into the patient's artery and the stent has been aligned in relation to a predetermined axial rotation and a horizontal position in relation to a heart valve (old) patient, the heart valve stent made independently of the positional stent is introduced into the artery or vein. The stent of the

ES 2 355 583 T3 heart valve, which carries the heart valve prosthesis at its proximal end, is automatically oriented during the insertion process thanks to the positioning stent that is precisely positioned and fixed to the artery wall. In particular, the heart valve stent expanded to its predetermined implantation position is automatically guided into the positioning stent by the positioning stent, where the heart valve prosthesis is optimally positioned relative to the heart valve. old of the patient. Once the heart valve stent has assumed its predetermined position with the aid of the positioning stent, relative to the old heart valve within the coronary vessel, the complete expansion of the heart valve stent is induced for example by external manipulation, consequently, the heart valve stent interacts according to the invention with the positioning stent, such that the heart valve stent, and therefore also the heart valve prosthesis provided at its proximal end, is fixed in position at the implantation site. Therefore, the position stent fulfills, not only the aforementioned function of determining the position of the heart valve prosthesis in the ventricle of the patient's heart as well as the function of anchoring or fixing the prosthesis in this position, but also during the implantation process the stent conduction function of the heart valve, to the optimal position for the heart valve prosthesis. The advantages that can be achieved with the device according to the invention are obvious: in particular, it is possible to carry out an optimal positioning of the heart valve prosthesis in its definitive implantation position, the alignment and fixation of the heart valve prosthesis taking place automatically. due to the interaction of the heart valve stent with the positioning stent. On the one hand, it can thus be ruled out that a defective implantation of the position-dependent heart valve prosthesis results. On the other hand, the device is characterized in that the implantation and fixation of the heart valve prosthesis can be carried out in a particularly simple way.

Due to the fact that according to the invention the positioning stent is designed as a self-expanding component that can be inserted into a patient's blood vessel, it can be placed beforehand, that is to say before the actual implantation of the heart valve prosthesis. provided at the proximal end of the heart valve stent. It could therefore be imagined that the positioning stent is pre-introduced into the aorta and optimally positioned and fixed there, then introducing the heart valve stent with the heart valve prosthesis, optimally fixing it by the stent. position that is already positioned and fixed there.

In accordance with the invention, both the heart valve stent and the positioning stent are self-expanding, which facilitates the respective insertion of these components. Due to the fact that the positioning stent, which assumes the task of determining the position for the stent of the heart valve or the prosthesis of the heart valve arranged therein, can be realized in a considerably smaller way, compared to prostheses. of current self-expanding heart valves, the maneuverability of the positioning stent is markedly increased, which ultimately results in the position in which the positional stent is anchored relative to the heart valve can be chosen by optimally adapting it with utmost precision to the respective needs. The advantage of the exact positioning of the stent, which is relatively easy to maneuver and of reduced dimensions, manifests itself during the subsequent implantation of the heart valve prosthesis, since the heart valve stent at the proximal end of which the valve prosthesis is provided cardiac is held in the predetermined position by the optimally positioned positioning stent.

With a view to inserting the heart valve stent, it is provided in accordance with the invention that the heart valve stent is designed in a reversible, collapsible and deployable manner. For this, it is conceivable that the heart valve stent can be folded, for example by external manipulation, and removed using an explantation catheter. For this, the heart valve stent can be housed in folded form in a cartridge that can be attached to a positioning stent catheter or an explantation catheter.

Advantageous developments of the device according to the invention are described in the dependent claims.

In order for the heart valve stent to be optimally inserted into a patient's blood vessel and positioned there in a predetermined position relative to the heart valve, the positioning stent needs to be as small as possible in its position. folded state, in order to thus allow optimal stent navigation with the least possible influence on the heart valve. This is achieved because the heart valve prosthesis to be implanted is not placed on the positioning stent but on the heart valve stent. Furthermore, the positioning stent is made in such a way that all the parts of the stent present in the folded state a certain degree of initial tension acting radially outwards, which after being released from a cartridge causes self-expansion. The positioning stent with the cartridge can then be implanted in a conventional way with the aid of a positioning stent catheter, for example through an inguinal artery. In the event that a positioning stent implantation defect occurs, for example if the positioning stent is not in the exact position in the patient's aorta or if for other reasons it is necessary to do the explantation of the positioning stent, it is provided that the positioning stent can be brought back from its expanded state back to the folded state. This takes place, for example, by external manipulation using an implantation catheter. Therefore, the positioning stent can be fully reversibly removed into the catheter, allowing for

ES 2 355 583 T3 complete removal of the stent.

In an advantageous form of the device according to the invention intended for transvascular implantation and fixation of heart valve prostheses, provision can be made for the positioning stent to have an anchor at its proximal end, in particular an anchor support, this support being made of anchoring such that the positioning stent is automatically positioned in its expanded state in a predetermined position relative to the patient's heart valve, being held with the help of the anchoring support. To this end, the positioning stent is made such that the anchoring post can be foldedly accommodated within a cartridge that can be attached to a catheter. For this, the anchoring support should be compressed in such a way that it presents an initial tension that acts radially outwards, and that when released from the cartridge it causes self-expansion. Due to the realization of the positioning stent in such a way that in its expanded state it automatically positions itself in a predetermined position relative to the heart valves of the patient, being held there with the aid of the anchoring support, it is possible that it can be determined in advance accurately position the stent position and thus the stent position of the heart valve, so that cases of erroneous implantation can be excluded, such as were possible with known solutions.

In order to facilitate self-expansion of the positioning stent, the positioning stent can advantageously have prestressing elements for pretensioning the positioning stent in a radial direction in its position determined by the anchor. To this end, the prestressing elements are also made reversible, in such a way that their prestressing function can be canceled by external manipulation, which makes it possible to fold the position stent and therefore have the possibility of removing the positioning stent piece into a catheter, or the complete removal of the positioning stent.

In an advantageous embodiment of the last-mentioned embodiments, provision is made for the anchoring support to have at least one support bracket which is designed in such a way that in the expanded state the positioning stent automatically seats itself in the cavities of the patient's heart valve, and thereby determine the orientation of the positioning stent in the axial and horizontal direction relative to the heart valve. For this, it could be imagined, for example, that the support stirrups made on the proximal side of the positioning stent are automatically placed during the implantation process of the positioning stent in the cavities of the heart valves of the respective patient, thereby constituting the cavities of the heart valves a counter-support that acts against the proximal movement of introduction, so that the anchor bearing with the positioning stent can be accurately positioned laterally. At the same time, it is ensured that the anchoring bearing and the positioning stent can adopt an exact angular position, since the cavities during the insertion act to a certain extent as a guide for the bearing stirrups. Only after the support stirrups have been inserted into the cavities of the heart valve of the respective patient and the final position for the positioning stent has been reached, the heart valve stent made independently of the positioning stent is implanted. using, for example, a heart valve catheter. The heart valve stent, which at its proximal end presents the heart valve prosthesis, is then optimally implanted in the most convenient and best location, thanks to the positioning stent that has already been precisely positioned and fixed. Another advantage that can be cited is that the positioning stent support stirrups seat after implantation of the positioning stent on the heart valve of the patient. Due to the fact that the positioning stent is produced in a relatively simple way, since, for example, it does not carry the heart valve prosthesis, which is provided in the heart valve stent made independently of the positioning stent, the stirrups of the Positioning stents can have a relatively large radius, which means a lower risk of causing heart valve injury.

The supporting stirrups on an anchor bearing or an anchor should be curved proximally in a convex and arc-shaped direction, as this rounded shape can prevent injury to the blood vessel in the heart and can facilitate deployment during self-expansion. With this configuration, the support stirrups can also be inserted more easily into the cavities of the old heart valve, without corresponding damage to the tissue or blood vessels existing there.

However, additional stabilizing stirrups can also be present in the anchoring supports, by means of which an increase in strength can be achieved after the anchoring support already anchored has self-expanded. These stabilization stirrups can be advantageous since to take advantage of the necessary self-expanding effect in an anchoring support to achieve a secure fixation of the anchoring support with the positioning stent, taking into account the fact that during the phase of introduction of a Anchoring support folded inside a cartridge, it is necessary to achieve the smallest possible volumes, it is necessary to maintain reduced sections for the respective stirrup.

For this, all the stirrups of an anchoring support should be arranged, configured and dimensioned in such a way that the successive release of supporting stirrups and of the other stirrups, as well as possibly other elements existing in an anchoring support, can be achieved. by means of the corresponding manipulation of the cartridge and / or the catheter. For this, of course, the configuration of the cartridge or

ES 2 355 583 T3 at least a part of the cartridge.

According to the anatomy, there should be three supporting stirrups arranged at equal angular intervals to each other on the anchor bearing. However, there is also the possibility that the support brackets on an anchor support are arranged with an angular offset relative to each other. In this case, in the implanted state, the supporting stirrups are inserted with their proximal parts into the cavity of an old heart valve, the old heart valve can then be clamped by pressing with the supporting stirrups.

The stability of an implanted and fixed positional stent can be optimally increased by at least one annular support, which may be an element of an anchor pad. Thus, it is possible to join the different stirrups present in an anchoring support by means of an annular support of this type, preferably at their foot points. For this, it is not absolutely necessary to provide a connection between the angle support and all the stirrups of an anchoring support.

Once the positioning stent has been positioned in the heart and secured there using the anchor pad, the heart valve stent is inserted. For this, it is advantageously provided that the heart valve stent is designed in such a way that the heart valve prosthesis presses the patient's heart valve against the wall of the aorta in its expanded state, the at least one anchor being located of the stent position between the wall of the aorta and the heart valve that has been deployed by means of the heart valve prosthesis.

In order to ensure that the stent of the heart valve can be held with the aid of the positioning stent in a position that can be predetermined by the positioning stent in relation to the patient's heart valve, the positioning stent has at its distal end at least one element interlocking. For this, the heart valve stent should have at its distal end a fastening element made in a corresponding complementary manner, where in the expanded state of the position stent and in the fully expanded state of the heart valve stent the at least one element of the at least one interlocking element of the positioning stent forms a force-fit connection with the at least one interlocking element. In this way it is possible to achieve that the heart valve prosthesis is positioned in the coronary vessel, in the position predetermined by the positioning stent, and is held there with the positioning stent. In this case, it could be imagined that interlocking stirrups are provided on the heart valve stent. The interlocking stirrups are part of the elements of the heart valve stent that are only released for expansion once the heart valve stent has been inserted through the position stent already implanted in the correct position at its implantation site in a patient's heart valve. As the heart valve stent locking stirrups are deployed, they engage the positioning stent locking elements and thereby secure the heart valve stent in the position predetermined by the positioning stent. At the same time, parts of the old heart valve of the respective patient are then placed between respective anchoring stirrups of the positioning stent and of the expanded heart valve prosthesis, so that the respective parts of the old heart valve are subjected to pressure between them. elements after the deployment of the heart valve prosthesis has taken place, similar to what happens with a paper between the stirrups of a paper clip.

The positioning stent is designed in particular in such a way that it only assumes its fully expanded state, in which both the prosthesis of the heart valve and also the holding element are released, when the stent of the heart valve is in the position predetermined by the stent position.

The heart valve stent is advantageously realized, like the positioning stent, in a reversible, collapsible and deployable manner, where in the retracted state the force-fit connection with the positioning stent is released. This enables the heart valve prosthesis provided in the heart valve stent to be re-explanted, for example in the event of a defective implantation, without also removing the positioning stent. .

In order to facilitate the explantation of the heart valve stent, explantation elements can be provided at the distal end of the heart valve stent which interact with the heart valve stent in such a way that, for example, by external manipulation The force-fit connection between the heart valve stent and the positioning stent is released from the explantation elements, and the heart valve stent is retracted. In an advantageous embodiment of the explantation elements, it is provided that they can be clamped using, for example, an explantation catheter, in which case by withdrawing the explantation elements into the explantation catheter the force-coupled connection between the heart valve stent and the positioning stent, and the heart valve stent is retracted.

Advantageously, the heart valve stent is housed in a collapsed state in a cartridge that can be attached to a heart valve stent catheter and / or to an explantation drive, the stent being able to be released from the heart valve by movement cartridge default. In particular, it is planned so

ES 2 355 583 T3 advantageous that by means of a first specified movement of the cartridge only the prosthesis is released from the heart valve to carry out its deployment, while by means of at least one subsequent movement of the cartridge or of the catheter the element is released. holding the heart valve stent.

Especially for subsequent movements to be performed by the cartridge and catheter, which result in the sequential release of the various elements of the stent from the heart valve, it may be advantageous to use a multi-part cartridge, in which at least least two individual parts can each move relative to the other. Thus, for example, the movements of a cartridge or of different parts of a cartridge that have to be carried out for self-expansion can be a proximal and / or distal movement, which can take place in several stages that have to be carried out successively, going through in each case different ways to release the corresponding parts in succession for their expansion at the respective moment of an implantation.

Thus, for example, the first movement may be a distal withdrawal of the cartridge or of a part of a cartridge. In order to avoid a defective implantation, in this case, if necessary, a proximal movement of the cartridge or a part of the cartridge can be used in order to retract the fasteners or the prosthesis of the heart valve of the stent. heart valve already deployed and acting radially outward with initial tension, housing them again in the cartridge so that it is possible to effect removal of the device from the patient. As an actuating element for handling and therefore for carrying out a displacement movement of the cartridge or of different parts of a cartridge, control cables or flexible push tubes can be used which lead to the cartridge or through the interior of the catheter. a part of the cartridge. Such actuating elements can, however, also engage fastening elements, for example eyelets, which exist on the anchoring bearing.

In the solution according to the invention there is therefore the possibility of interrupting an implantation of a heart valve prosthesis that is not going to be successful, and removing the device again by removing the catheter, for which the heart valve stent that is already has been deployed, it can be retracted and removed into a cartridge or part of a cartridge.

In an advantageous development of the device according to the invention, provision is made for the positioning stent to also have anchoring elements, in particular hooks for anchoring the positioning stent to the heart in its predetermined position. It would also be possible that, additionally or alternatively to the positioning stent, the heart valve stent has anchoring elements such as, for example, hooks, to anchor the heart valve stent in the aorta in the predetermined position by means of the positioning stent. . Both solutions ultimately serve to securely fix the implanted heart valve prosthesis at its implantation site predetermined by the positioning stent.

In order to facilitate orientation in space when inserting the positioning stent, markers, in particular X-ray markers, can be provided on the positioning stent. But of course other solutions are also possible. For example, the positioning stent can also be monitored and controlled using fluoroscopy (cardiac catheter laboratory = HKL) or ultrasound (transesophageal echocardiogram = TEE).

The positioning stent and / or the heart valve stent may also have conduction means that are designed in such a way that the heart valve stent is led to the position predetermined by the positioning stent inside the stent of position automatically expanded. For this, it could be imagined that the conduction means are made as elements that gradually reduce in section towards the distal end of the positioning stent or of the heart valve stent, so that an automatic adjustment of the heart valve stent can take place. within the positioning stent and therefore in the position predetermined by the positioning stent.

The device according to the invention can also be used in conjunction with a balloon catheter. With the balloon catheter, the old heart valve can be pushed aside before self-expanding the anchor pad.

Preferred embodiments of the device according to the invention for implantation and fixation of heart valve prostheses are described in greater detail below, using the accompanying drawings.

These show:

FIG. 1 a preferred embodiment of a positioning stent of the device according to the invention, in the positioned and expanded state;

FIG. 2A a preferred embodiment of a heart valve stent of the device according to the invention, in an expanded state;

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Fig. 2B the heart valve stent shown in Fig. 2A, in the implanted state;

Fig. 3A, B respective schematic representations to explain the explantation process of a preferred embodiment of the heart valve stent, and

FIG. 4 a detailed representation of the explantation elements provided in the heart valve or in the positioning stent, as well as their operation.

Fig. 1 shows a preferred embodiment of a position stent 20 of the device according to the invention, in the placed state. In the embodiment shown, the position stent 20 is in its expanded state. As shown, the positioning stent 20 has at its proximal end an anchoring segment 21 'with anchoring pads 21. The anchoring pads 21 are made in such a way that they are automatically optimized in the T chambers of the old heart valve with respect to axial rotation as well as horizontal position. For this, the positioning stent 20 is supported by means of the anchoring supports 21 in the cavities T of the old heart valve. The anchor supports 21 themselves are connected via bridges 22 with a coupling segment 23. The coupling segment 24 'of the position stent 20, which is provided at its distal end, has a plurality of position elements 24 by means of which a heart valve stent to be implanted is fixed (not explicitly shown in Fig. . 1).

The position stent 20 is made as a self-expanding component. Of bido to the simple structure of the positioning stent 20, which consists essentially only of the anchoring segment 21 ', of the coupling segment 24' and the bridges 22, the positioning stent 20 has in its folded state a reduced extremely dimensions. By introducing the position 20 stent, for example by using a position stent catheter, the position 20 stent can therefore be maneuvered very well into the aorta A. Once the position 20 stent has been inserted into the aorta A, this is deployed which takes place for example by external manipulation of the catheter of the positioning stent. The anchoring posts 21 of the expanded position stent 20 automatically engage in the cavities T of the patient's heart valve whereby the alignment of the position stent 20 relative to the heart valve, in the axial and horizontal directions, is determined. In order for the deployment of the positioning stent 20 to take place automatically, suitable pretensioning elements may (optionally) be provided. In the embodiment shown there are prestressing elements made in the form of the anchoring supports 21.

Once the position stent 20 has been introduced into the aorta A and is positioned and fixed there in the manner described above, a heart valve stent 10 is inserted into the position stent 20, which at its proximal end comprises a stent prosthesis. heart valve 11. This unfolds after release and compresses the old valve against the wall of the aorta or against the 20 position stent.

In FIG. 2A, a heart valve stent 10 is shown in an expanded state. As shown, the heart valve stent 10 carries at its proximal end the heart valve prosthesis 11 and at its distal end an anchoring segment 12 'which has at least one clamping element 12.

FIG. 2B depicts how the heart valve stent 10 is attached to the position stent 20 that is already positioned and secured. The heart valve stent 10 is guided by means of conduction elements 17, 27 in the position stent 20 in such a way as to axial rotation and position that the new heart valve is in an optimal position. Once this has happened, and by continuing to release the stent from the heart valve 10, its anchoring segment 12 'is inserted into the engagement segment 24' of the position stent 20. The anchoring segment 12 'has clamping elements 12 that form a force-coupled connection with the locking elements 24 of the position stent 10, in order to position the heart valve prosthesis 11 in the coronary vessel in the predetermined position. by position stent 20, holding it there by means of position stent 20.

Unlike a conventional heart valve stent, the heart valve stent 10 of the present device does not have retaining brackets that fit behind the old heart valve but instead interlocking brackets in the form of retaining elements 12 in the anchoring segment. 12 of the heart valve stent 10. These interlocking stirrups interact with the interlocking elements 24 which are provided in the coupling segment 24 'of the position stent 20. The advantage of this is that the heart valve stent 10 is anchored in the position stent 20 interchangeably. Due to its self-localization which is achieved by the conduction elements 17, 27 the heart valve stent 10 automatically slides into the position stent 20 and cannot continue to slide any further. The conduction means 17, 27 are realized as elements that taper towards the distal end of the position stent 20 and / or the heart valve stent 10. By means of the special configuration of the locking elements 23 of the position stent 20 and of the fastening elements 12 of the heart valve stent 10, in the form of zig-zag stirrups (period Z stirrups), it is possible to carry out in particular, a more precise angular position of the heart valve stent 10. Both the position stent 20 and the heart valve stent 10 can be made up of individual segments, with the individual segments being twisted relative to each other. This increases the flexibility by which the

ES 2 355 583 T3 two stents can be placed in the aorta. In particular, it is possible to carry out a more precise angular positioning of the heart valve stent 10. Thus, for example, it is possible to imagine that the heart valve prosthesis 11 has been placed by the doctor randomly rotated. Also with a view to refolding the heart valve stent and the positioning stent, the segment-shaped structure has advantages, since the stents can be accommodated in a catheter folded twisted into segments.

FIG. 3A shows a schematic representation of how heart valve stent 10 can be explanted into position stent 20 already positioned and implanted. In the event of valve dysfunction, the above-described fixed mechanical connection between position stent 20 and heart valve stent 10 can be re-released by external manipulation. This is done for example by collecting the explantation elements 13 with a catheter 30 and a cartridge 33 attached thereto. After collecting the explantation elements 13 inside the explantation catheter 30 made with a variable funnel shape, the stent of the heart valve 10 is introduced by pulling it inside it, thus being able to replace it with a new one. The position stent 20 remains as a mark and anchor base for a new heart valve stent 10. Of course, the stent at position 20 can also be explanted in a similar way.

The coupling segment 23 'of the positioning stent may have rings or protrusions in which the explantation catheter 30 must be attached to achieve such explantation. Ring attachment can preferably be done by means of three to six rings and three to six loops, which are then removed by pulling the rings out. In particular, the positioning stent 20 and also the heart valve stent 10 can be completely reversibly collected inside the catheter, which allows the total removal of the positioning stent and / or the stent from the heart valve.

It is possible to loosen the firm mechanical connection between the position stent 20 and the heart valve stent 10 by external manipulation, for example in the event of valve dysfunction, since for this purpose the stent The previously implanted heart valve 10 has a suitable retrieval design. This consists of several connecting bridges that protrude from the outer end of the stent medially into the vascular lumen, and meet there in an anchoring device (ring, hook, protrusion, etc.). If this anchoring device is now secured by the retrieval wire of the catheter 30, the stent of the heart valve 10 can be collected in its distal part towards the lumen, pulling it into a flexible catheter tube 33. There is then the possibility of using the position stent 20 that remains in place again, as a mark and anchor base for a new heart valve stent 10.

The position stent 20 is made of a firm braid (wire, polymer, etc.) or produced by a laser cutting process. Suitable materials for the positioning stent include NiTi, stainless steel or biocompatible plastics. For orientation in space, radiographic markings can also be placed on the position stent 20.