Catheter for the transvascular implantation of prosthetic heart valves

[0001] The present invention relates to a catheter for transvascular implantation of a heart valve prosthesis with self-expanding anchor supports with which minimally invasive implantation of heart valve prostheses is possible.

[0002] Publication WO 2004/019825 A1, presenting the closest prior art, relates to an apparatus for implanting and fixing heart valve prostheses together with a heart valve prosthesis attached to a self-expanding anchor support. The self-expanding anchor support is placed in a complex form in a cartridge that can be connected to the catheter. On the proximal self-expanding anchor support, support brackets have been made that can be inserted into the patient's heart valve pockets. The support holders are released from the cartridge by means of a predetermined first cartridge movement. By at least one subsequent movement of the cartridge and / or catheter, the subsequent elements of the anchor support are released together with the heart valve prosthesis until they are completely expanded and anchored.

[0003] Document US 6273876 relates to a flexible catheter, in particular for precise drug delivery.

[0004] Document US 2004/0243143 relates to a catheter delivery system which is also characterized by increased flexibility. [0005] Document WO 1999/53987 A1 relates to a flexible catheter guide system in a sleeve, which consists of at least one, guided and operated using a flexible sleeve running along the axis, having a longitudinal recess for placing and guiding catheters or similar longitudinal surgical instruments .

[0006] Document EP 0 411 118 B1 relates generally to a cylindrical stent made of shape memory material and which can be inserted by means of a catheter into the patient's body.

[0007] Patients are increasingly being required to implant heart valves, with both artificial and biological heart valve prosthesis implants being used.

[0008] Until now, such operations have been carried out in such a way that an anesthetized patient had to use a heart-lung apparatus. It is an expensive surgery during which the patient experiences a high mental and physical load. Mortality should be kept below 3%. In the elderly and with advanced damage to the heart valves, the patient requiring surgery cannot undergo surgery. Because surgical replacement of heart valves is not possible in these patients, they complain of reduced quality of life, and its length is significantly reduced. However, the risk associated with the procedure would be extremely high.

[0009] This situation also applies to operations in which cardiac valve prostheses with anchoring systems are implanted using so-called balloon catheters.

[0010] In this way, positioning errors may occur, which may have significant consequences for the patient, which may even lead to his death.

[0011] Therefore, in the recent past, attempts have been made to implant heart valve prostheses during procedures with minimal invasiveness, where such prostheses together with anchoring supports are guided through the patient's aorta and through it to the heart. After reaching the place of implantation in the heart, the automatic expansion of this type of anchor supports was initiated, to which the heart valve prosthesis is attached, which expansion would lead to a secure attachment and precise location of the heart valve prosthesis. Such anchoring supports were previously made of shape memory alloys, for example nitinol, the alloy selected so that its transformation temperature was about 37 ° C, and when the transformation temperature was reached, the automatic expansion process was triggered.

[0012] Due to this type of expansion, the anchoring support unfolds so that it can adhere to the wall of the aorta and can be securely fixed there, possibly using additional elements with a curved hook. At the same time, the heart valve prosthesis is folded out so that it can take over its function.

[0013] Such an anchoring support with a heart valve prosthesis is described, for example, in document WO 2004/019825 A1.

[0014] Supporting brackets have been made on this type of anchor support from the proximal side, which can be inserted into the patient's heart valve pockets so that the anchor supports can be positioned very precisely during surgery using these support handles. The anchor support should also be equipped with a commissioning grip, which, together with support grips, clamps parts of the patient's old heart valve after the anchor support has been unfolded, which means that the anchor support can be securely placed and secured as a result of this clamping.

[0015] The support and commissioning brackets in this known anchoring support should be arranged in such a way and have such dimensions that it can occur in the sequential self-expansion. This means that the anchoring support during implantation is placed inside the cartridge. It is guided through the catheter through the aorta to the patient's heart.

After reaching the implantation site, the cartridge should be handled so that the support handles can be released for their automatic expansion. Then the cartridge with the anchoring support is displaced and directed so that the support grips are inserted into the patient's heart valve pockets. Thanks to this, very precise placement can be ensured.

[0016] Then, the given cartridge is further manipulated, whereby the commissioning handles are also released and can be self-expanding. The old heart valve is clamped between the support handle and the commissioning handle, and the heart valve prosthesis is expanded, assuming a distributed functional position.

[0017] After implantation of the anchor support together with the heart valve prosthesis, the catheter can then be removed from the patient's body with the cartridge back through the aorta.

[0018] Although, as mentioned earlier, the simplified and improved positioning of the implantable heart valve prosthesis to be implanted can be provided with the aid of the anchor support, it is possible that the implantation will fail and the heart valve prosthesis will not be able to function or only insufficiently. Removal of such an inoperable or unsatisfactory cardiac valve prosthesis in some cases is then no longer possible or there is an increased risk of patient death.

[0019] Another problem in this type of surgery is also the aortic arch in the human body that must be passed through when the instrument is inserted through the aorta. During the movement of the cartridge and the given catheter, the direction should be changed by approximately 180 ° with a relatively small radius of approximately 50 mm, without damaging the vessel wall.

[0020] Accordingly, the object of the invention is to reduce the risk during implantation of heart valve prostheses.

[0021] This object is achieved as stated in claim 1. Advantageous further embodiments of the invention are described in the dependent claims.

[0022] In connection with a catheter according to the invention, a heart valve prosthesis with a self-expanding anchor support as known from WO 2004/019825 A1, to which the disclosure relates, can be used in accordance with a preferred embodiment.

[0023] The anchor supports with the cardiac valve prosthesis attached thereto during implantation are temporarily positioned inside the cartridge unit in a folded form.

[0024] The cartridge unit thus prepared can be detachably attached to the guide system from the proximal side. The outer diameter of the cartridge unit and the guide system has been kept to a minimum, to the extent that they can easily be guided through the aorta of the operated patient, while the entire free cross section accessible inside the aorta should not be completely filled.

[0025] The guide system is of sufficient length so that the cartridge unit together with the guide system can be guided by entering through the opening in the patient's groin, through the aorta, into the patient's heart.

[0026] The guide system has a flexible, flexible area that allows obtaining a bend radius and bend angle that corresponds to the aortic arch and allows it to be included.

[0027] Actuators are guided through the hollow guide system to the cartridge unit. With the help of the actuating element, the parts of the cartridge units can be manipulated and moved. Thus, radial as well as lateral movement of parts of the cartridge unit can be realized with the use of actuating elements. By using the intentional movement of a portion of the cartridge unit, sequential release of the anchor support portion can be achieved, whereby implantation can occur along with the anchoring, as mentioned at the beginning of this description and in WO 2004/019825 A1.

[0028] Thus, for example, the support brackets of the anchor support can be released by rotating or lateral movement in the proximal or distal direction of a part of the cartridge unit, but at the same time other parts, e.g. the commissioning handles, remain inside the cartridge unit in a folded form and then can be released to expansion by appropriate movement of the next part of the cartridge unit or further movement of the same part of the cartridge unit, which previously held the support handles in a folded form inside the cartridge unit.

[0029] The unfolding of the cardiac valve prosthesis which has been attached to the anchor support, for example by suturing, then proceeds simultaneously with the expansion of the respective anchor support holders on which the heart valve prosthesis is attached.

[0030] In a preferred embodiment, in addition to the actuating elements intended for parts of the cartridge unit, further actuating elements are guided through the hollow guide system to engage the flexible area to affect its curvature.

[0031] In particular, by generating tensile forces using actuators, a deliberate curvature of the flexible area can be achieved during implantation as it passes through the aortic arch. Thus, as pulling elements you can lead pulling cables or pulling wires through the hollow guide system up to the proximal edge of the flexible area, where you can attach them to the guide system, where the points of application of force of two such actuating elements should be located on opposite sides, and the 90 ° position relative to the bending axis is chosen, with respect to which the flexible area should be curved.

[0032] In this way, the curvature of the flexible area can be deliberately influenced by the action of a tensile force through one of the current actuating elements when the guide system is moved along with the flexible area through the aortic arch, or is removed from it after implantation.

The flexible area of ​​the guide system can be made in the form of a chain link in which the individual members are connected to each other by individual joints. The individual joints attach to the adjacent members forming a shaped connection. They are made so that the curvature of the flexible area above 180 ° can be maintained with a bending radius, which ensures that at least an aortic radius can be obtained.

[0034] The individual joints at the individual links of the link chain should be made in pairs on opposite sides on the individual members and at the same time parallel to the axis of rotation of the flexible area.

[0035] The guide system used in the catheter of the invention should preferably be made so that it will be possible to guide the liquid coolant or drugs through the hollow system leading to the cartridge unit. By using this kind of liquid coolant, for example sodium chloride solution, the anchoring support can be kept below the transformation temperature of the shape memory alloy. In addition, it can also be avoided that body fluid could penetrate into the interior of the guide system, while maintaining adequate fluid pressure that sufficiently prevents the ingress of body fluid or other components contained in the body fluid.

[0036] With the proper introduction of a liquid cooling agent, however, gas, in particular air, cannot enter the aorta and blood.

[0037] To this end, the entire guide system should be made in a liquid impermeable manner. Accordingly, the flexible flexible area, which is made in the form of a chain link, can be sealed from the outside using a plastic hose in a liquid-tight manner.

[0038] The parts of the cartridge unit that are movable to release the anchor support handles are preferably made as sleeve-shaped elements whose inner and outer diameter are so fitted that they can telescope into each other, at least two of the elements in the shape of the sleeves have internal and external diameters matched so that between them a folded anchor support with a heart valve prosthesis is placed and can be kept there in a folded form.

[0039] When inserting the catheter, the cartridge unit should be closed and for easier guiding through the aorta have a proximal side on the proximal side, which in turn is particularly preferably made of flexible material, for example silicone.

[0040] Once the cartridge unit has reached the patient's heart, appropriate manipulation can be carried out, i.e., the movement of the cartridge body / parts in such a way that the individual holders of different types of anchor support are released sequentially and at the same time the heart valve prosthesis attached to them is unfolded. .

[0041] The anchor support remains here still attached to the cartridge unit. For this purpose, anchor elements are made on the sleeve-shaped element of the cartridge unit, which engage from the distal side, for example, on eyelets made there on the anchor support. These anchoring elements are in this position together with the distally located part of the anchor support covered by the sleeve-shaped element of the cartridge unit, so that the distally located part of the anchor support is still kept in the folded form. [0042] In this position, it is possible to check the function of the already unfolded heart valve prosthesis. After positive verification of the correct operation of the heart valve prosthesis, you can proceed to further manipulation by appropriate movement of the sleeve-shaped element that previously covered the anchoring elements with a distal part of the anchor support, which manipulation leads to the complete release of the distal part of the anchor support, and thus to complete distribution.

[0043] If it is found during the inspection that the implanted heart valve prosthesis cannot perform its function or may not do it sufficiently, according to a particularly advantageous solution there is a possibility of displacement by means of the opposite opposing movement of the sleeve-shaped parts / elements anchoring support with heart valve prosthesis inside the cartridge unit as well as removing all parts, i.e. the entire catheter, through the aorta from the patient's body, whereby the risks associated with surgery can be significantly reduced, and then re-implantation attempted in the same patient.

[0044] In a preferred embodiment of the catheter of the invention, a guide wire can also be passed through the entire catheter. These types of guides are already being used in similar operations, but they are guided through the patient's aorta up to the heart before the catheter is inserted. The catheter can then be threaded through the cartridge unit and guide system onto the guide and along it inserted into the aorta to the patient's heart.

[0045] To control the course of the catheter insertion, as well as to manipulate the flexible area, in particular in the aortic arch, preferably on the guide system and / or cartridge unit, marker elements are made of a material that absorbs X-rays, so that during surgery recognize their location on an x-ray.

[0046] A protective filter may also be used on the catheter of the invention to prevent particles from entering the patient's bloodstream. This type of protection filter can be attached to the guide system so that it surrounds it completely. It should be elastically pre-tensioned, which adheres to the vessel wall to the aorta and is able to provide protection against the ingress of particles.

[0047] The catheter according to the invention can additionally be made together with a conventional balloon, which is located inside the guide system or cartridge unit and there it can be co-guided there, or it can be guided through the interior of the guide system up to the expanded anchor support. By using this type of balloon, which can be appropriately enlarged, for example by liquid under pressure, the expansion of the anchor support can be further assisted.

[0048] The aforesaid actuating elements guided inside the guiding system, which can be made as pulling or pressure elements, can be advantageously manipulated by the operating part. The operating part can be made in the form of a handle, with which the operator can then make the catheter insertion movement.

[0049] Further operating elements are arranged on this type of operating part, with which a given movement of the actuating elements can be triggered. It must be possible to make the appropriate movement in the most metered manner possible, for example using the appropriate ratio, as well as the possibility of restricting the movement at least by means of end stops or latching positions. In this way, the maximum sections or angles to be overcome can be kept to be considered for the purposes of sequential expansion of the anchor support or specific influence on the curvature of the flexible area. It should be possible to fine-tune the end stops or individual latches.

[0050] All parts of the catheter of the invention, or at least those that are in direct contact with the patient, or are also introduced into the aorta, should be made of biocompatible materials that are tolerated by the body. In addition, it should be possible to sterilize them, with the possibility of using at least one conventional sterilization method.

[0051] The invention will be explained in more detail below with an example.

[0052] The drawings show:

figures 1 to 4 schematically show an example of a catheter according to the invention in various possible phases of the implantation process;

Fig. 5 shows an example of a catheter with an operating part;

Figure 6 is an exploded view of the operating part according to Figure 5.

[0053] Figs. 1-4 show an example of a catheter according to the invention, the purpose of which figures is to make it more understandable. The individual drawings show the various phases that may occur during implantation of the anchor support 10 together with the heart valve prosthesis.

[0054] Fig. 1 shows an example of a catheter according to the invention such that in the cartridge unit 4, which is still completely closed, the anchor support 10 is placed together with the heart valve prosthesis in an unstressed and suitably folded form, in which form empty guiding system 1 this catheter can be inserted through the appropriate entrance to the aorta and through it to the appropriate implantation site in the patient's heart.

[0055] On the cartridge unit 4 on the proximal side is a flexible silicone tip that facilitates insertion and reduces the risk of injury.

[0056] Part 5 of the cartridge unit is removably connected to other parts of the guide system 1, for example by a bolted connection.

[0057] The cartridge unit 4 is adjacent a flexible area 9, which is made in such a way that is dimensioned so that it allows unhindered movement within the patient's aortic arch.

[0058] The possibilities of making this type of flexible area 9 will be discussed later.

[0059] Furthermore, further parts of the hollow guide system 1 are shown, wherein in Figs. 1 to 4 two actuating elements 2 and 3 are guided through the guide system 1 to the cartridge unit 4, the guide element 2 being guided to the cartridge unit 4 through the hollow actuator 3 as well.

[0060] The actuating elements 2 and 3 are made here in the form of compression springs, which are preferably reinforced with pull wires. This type of wire can increase safety when removing the catheter from the patient's body after surgery.

[0061] On the left side further parts 11 of the guide system 1 are shown, which can for example be made of more or less flexible sleeve-shaped parts, while it must be ensured that they will be of a sufficiently high quality for entering the aorta and re-emerging from it. compressive and tensile strength. Suitably rigid plastic hoses can be used here, for example PTFE hoses or PTFE-based hoses, since they are sufficiently tolerated by the body and can be sterilized.

[0062] Fig. 2 shows how to proceed in the first stage of surgery after reaching the implantation site in the patient's heart. By the distal movement of one of the actuating elements 2 and / or 3, the sleeve-shaped part / element 7 of the cartridge unit 4 can be retracted in the distal direction, whereby the selected anchor support brackets 10, and, for example and preferably also support brackets, which should be present in the case of heart valve prostheses known from WO 2004/019825 A1, expand and decompose radially outward.

[0063] Thus, the entire catheter together with the guiding system 1 and the cartridge unit 4 can be moved in the proximal direction, and in this way these handles (support handles) are inserted into the pockets of the patient's old heart valve. If the operator senses a clear resistance, it is likely that the process of inserting support brackets, anchor support 10 into the pockets of the old heart valve, was successful. [0064] The sleeve-shaped part / element 5 of the cartridge unit 4 can be moved further distally forward, whereby the subsequent anchor support handles are also released, which results in their self-expansion and the heart valve prosthesis is folded out.

[0065] The initial stage of this process is shown in Figure 3, whereby the heart valve prosthesis has not yet fully unfolded and the anchoring support 10 has not yet been completely anchored.

[0066] In Fig. 3 it is further seen that the distal portion of the anchor support 10 is still inside the cartridge unit 4, under the sleeve-shaped part / element 7 in the cartridge unit 4. This is until the unfolding and positioning of the heart valve prosthesis is advanced enough that the prosthesis can be checked for functionality.

[0067] If, as a result of such inspection, a malfunction or incorrect position is detected, the sleeve-shaped part / element 7 can be moved proximal again by means of one of both actuating elements 2 or 3, whereby the anchoring support 10 together with the heart valve prosthesis at least in part it will be back in cartridge unit 4, and then the entire catheter can be removed from the patient's body by pulling it out of the aorta, the vessel wall will not be damaged.

[0068] If, when checking the operation of the heart valve prosthesis, it appears that it can perform its function at least sufficiently, the sleeve-shaped part / element 7 can, as shown in Figure 4, be retracted further distally and / or the distal part / element The sleeve-shaped cartridge unit 4 can be moved in the proximal direction, whereby also the distal portion of the anchoring support 10 can be released completely and can expand completely.

[0069] In addition, it can be clearly seen in Fig. 4 that in the distal end region of the anchor support 10 there are eyelets or other suitable elements which have previously engaged the anchor elements 8 which are made on the sleeve-shaped part / element 6. By means of these eyelets together with the anchoring elements 8, it can be ensured that in the event of unsuccessful or incorrect implantation of the anchor support 10 together with the cardiac valve prosthesis, certain retraction and removal can be ensured, while the anchor support 10 and the cardiac valve prosthesis are removed from the patient.

[0070] By means of the anchoring elements 8 and possibly also further guiding elements 16, which can be made on the sleeve-shaped part / element 6 of the cartridge unit 4, it is also possible to provide radial rotation to be able to insert the anchor support brackets 10 into, for example, pockets of an old heart valve prosthesis also in exact angular orientation, during implantation, the entire catheter can be easily rotated about its longitudinal axis by the operator.

[0071] In particular, in detail view A in Fig. 4, cannula 12 is also recognized, which is guided through the cartridge unit 4 along its longitudinal axis. With the cannula 4, for example, the guide mentioned in the general part of the description can be guided through the cartridge unit 4.

[0072] Fig. 5 shows an example of a catheter with an additional operating part 13, in which further operating elements for handling are provided.

[0073] The guide system 1 together with the cartridge unit 4 shown previously in Figs. 1 to 4 also corresponds to the example shown here.

[0074] Detail A, however, shows a possible solution for the flexible area 9, which is here made in the form of a chain link.

[0075] The individual members 9.1 have essentially the same shape and dimensions.

The facing front sides of the individual members 9.1 are arranged in such a way that they form individual joints 9.2, which in each case engage, forming a form connection, on adjacent individual members 9.1, with the result that sufficient slots are provided in each case the width of the gap between the individual members 9.1, these joints allow flexing of the flexible area at the aforementioned angle of at least 180 °, with a radius of about 50 mm.

[0077] The individual joints 9.2 are thereby made by appropriately shaping the facing sides of the individual members 9.1, the single joint 9.2 being formed by a corresponding recess on one face side and a corresponding, rounded, matching elevation on the facing side facing it. adjacent individual members 9.1.

[0078] The flexible area 9 may be surrounded by a liquid impermeable plastic hose, which is not shown in the drawing.

[0079] Fig. 5 further illustrates how the operating part 13 for inserting and manipulating the catheter according to the invention can be made.

[0080] A handle 13.1 was used to insert and withdraw the catheter with the guide system 1 and the cartridge unit 4. [0081] In the proximal area of ​​the operating part 13, a liquid-impermeable closure in the form of a plate 17 is provided, on which the flange connection of the guide system 1 is provided by means of a union nut 23 and sealing elements not shown here.

[0082] In addition, a standardized Luer connection 30 was used through which the cooling liquid can be fed. [0083] With the help of the handle 19, which can be rotated about an axis, a certain curvature of the flexible area 9 can be obtained by means of a pulling rope (not shown in the drawing), more detailed explanations on this subject being given when discussing Fig. 6.

[0084] The entire operating part 13 should be sealed, not passing liquid and / or gas, to the environment and the guide system 1.

[0085] By means of the lever 20 catching on the handle 13.1, a transverse movement of the pipe 28 can be made in the proximal direction, as a result of which the corresponding movement and the resulting tensile force or pressure force on one of both actuating elements 2 and / or 3 can be transferred, so that individual parts / components can be handled

5, 6 in the form of sleeves and / or 7 cartridge unit 4, as already described, for example, with precise dosing of the pumping movements of the levers 20.

[0086] With the aid of the push-in handle 25, the position of the cartridge unit 4 part 4 in relation to the sleeve-shaped part 4 of the cartridge unit 4 with the fastening hook as the anchoring element 8. can be manipulated by the position of the cartridge part 8 is coupled by a compression spring to the threaded teeth 28.1 of the pipe 28. In this way, the push-in handle 25 follows the proximal movement of the pipe 28, which is connected to the cartridge part 6 via a spring as an actuating element 3.

[0087] After reaching the end stop in the first release step, one can achieve by turning the push handle 25 by a thread pitch of 28.1, a precise axial displacement of the part 5 of the cartridge unit 4 relative to the part 6 of the cartridge unit 4.

[0088] To actuate the push handle 25, it can move part 5 of the cartridge unit 4 without additional fine adjustment.

[0089] Thanks to this type of manipulation, the anchoring support 10 can be released (see Fig. 3), while the anchoring support 10 in this position can still be retracted.

[0090] After releasing the stop 29 by the adjusting member 31, which is, for example, made in the form of an adjusting screw, the cartridge unit 4 can be extended by actuating the lever system 20, as already described, until the anchor support eyelets 10 release the cartridge unit 4 and the anchor support 10 can jump away from the anchor elements 8 due to the expansion forces.

[0091] The elements of the cartridge unit 4 can be retracted gradually. Whereby part 5 of the cartridge unit 4 can be retracted by pulling the push handle 25 (engaged lock) up to the part 6 of the cartridge unit 4.

[0092] By actuating the unlocking bolt 32, it is also possible to retract the part 6 of the cartridge unit 4 connected to the pipe 28 to its initial position by further pulling the push handle 25 back, so that the cartridge unit 4 is completely closed again. In this condition, the catheter can be removed from the patient.

[0093] Fig. 6 is an exploded view of the operating portion 13 used in this example in more detail. [0094] It can be seen here that by turning the hand wheel 19 on the shaft 14 it is possible to cause two toothed racks 24 to be displaced in parallel. One toothed bar 24 moves in the proximal direction and the toothed bar 24 parallel to it moves in the distal direction.

[0095] To the clamping jaws 24 coupled to the toothed bars 24, pulling lines not shown here can also be attached, which are guided into the flexible area 9 through the hollow guide system 1 and are preferably attached in its proximal area.

[0096] By properly rotating the handle 19, at least one of the two pulling cables can be subjected to a tensile force that leads to a corresponding curvature of the flexible area 9 in a gradual manner, whereby the guide system 1 can be guided together with the cartridge unit 4 in a certain form through the aortic arch .

[0097] In Fig. 6 it is further seen that the lever 20 connected to the handle 13.1 through the toothing 28.1 engages with the pipe 28, which can then be manipulated via actuators 2 and / or 3 for the sequential release of the anchor support 10.