Method for robotic repositioning of pre-crimped drug-coated stents

Abstract

The present invention relates to a method for repositioning a drug-coated stent (2), wherein the drug-coated stent (2) is pre-curled on a balloon (30) of a balloon catheter (3) extending in an axial direction (z) so that an inner surface (2a) of the stent (2) abuts against an outer surface (30b) of the balloon (30), the method comprising the following steps: moving the stent (2) in an axial direction (z) relative to the balloon (30) of the balloon catheter (3) by at least one contact element (40, 41, 42) to reposition the stent (2) relative to the balloon (30), and in order to reposition the stent (2), at least one contact element (40, 41, 42) clamps the stent (2) with a protective device (60, 61, 62; 70) therebetween to prevent contact between the stent (2) and at least one contact element (40, 41, 42).

Description

Technical Field

[0001] The present invention relates to a method for repositioning a stent pre-crimped on a balloon of a balloon catheter. Background Art

[0002] Typically, such repositioning of the stent is performed so that the stent sits in a precisely defined position relative to the balloon of the balloon catheter so that its position can be identified during implantation, for example using X-ray markers arranged on the balloon catheter, and defined expansion of the stent by the balloon is possible.

[0003] In the prior art, such repositioning of stents by manual means is known, the stent in question being manually moved or repositioned, for example, by gloves. Furthermore, machine repositioning of non-drug coated stents is known, which involves contacting and moving the stent by a mechanical clamping mechanism.

[0004] Furthermore, EP 1807021 describes a method in which a stent is arranged between two films which substantially surround the stent as it is crimped onto a catheter.

[0005] Furthermore, EP 2590601 discloses a method for deploying a stent on a balloon using a fork to protrude into the proximal end of the stent and push the stent forward over the balloon.

[0006] During the automated processing of drug-coated stents, cross contamination needs to be prevented. To this end, the parts of the device used for repositioning that come into contact with the stent must be cleaned or replaced after each production run. This makes machine repositioning of the stent very laborious and therefore cost-intensive. Summary of the invention

[0007] Starting herefrom, therefore, the present application has the object of providing a method for repositioning a pre-crimped drug coated stent which prevents cross contamination of the balloon catheter.

[0008] This is achieved by a method having the features of claim 1. Advantageous embodiments of this aspect of the application are indicated in the corresponding dependent claims and are described below.

[0009] A method for repositioning a drug-coated stent is proposed, wherein the drug-coated stent is pre-crimped on a balloon of a balloon catheter extending in an axial direction so that the inner surface of the stent abuts against the outer surface of the balloon, the method having at least the following steps:

[0010] - The stent is moved in an axial direction relative to the balloon of the balloon catheter by at least one contact element to reposition the stent relative to the balloon, and in order to reposition the stent, at least one contact element clamps the stent, wherein a protective device is therebetween to prevent contact between the stent and the at least one contact element.

[0011] During angioplasty procedures, such stents are used, for example, to keep a patient's blood vessel open, the stent being delivered to the implantation site by a balloon catheter and anchored in the vessel by inflating the balloon. In addition, drug coating refers to stents being coated with at least one drug that is delivered to the patient's body, for example, after the stent is implanted.

[0012] One embodiment of the method provides that at least one contact element is moved away from a first position toward the balloon catheter to a second position so that at least one contact element reaches behind the surface of the stent with a protective device in between, or in order to clamp the stent, the contact element is pressed against the stent with the protective device between the contact element and the stent.

[0013] One embodiment of the method also provides that, in order to reposition the stent, at least one contact element located in the second position moves along the balloon catheter in the axial direction with the stent, and the balloon catheter is fixed in the axial direction. Another embodiment of the method provides that, in order to reposition the stent in the axial direction along the balloon catheter, the balloon catheter is pulled in the proximal direction by at least one contact element, and the at least one contact element holds the stent in place in the axial direction, preferably at the distal section of the stent, thereby fixing it.

[0014] One embodiment of the method also provides that, in order to reposition the stent, the stent is moved in the axial direction until the distance in the axial direction from one end of the stent to an X-ray marker arranged on the balloon catheter corresponds to a predetermined distance. Preferably, this end of the stent is the distal end of the stent. In addition, the X-ray marker is preferably a distal X-ray marker. Here, the distal side refers to a component called the distal side that is arranged away from a person who manipulates the balloon catheter during implantation, and the person operates the balloon catheter from the proximal end of the balloon catheter. Therefore, the proximal end of the stent is arranged to be closer to the aforementioned person along the balloon catheter than the distal end. This also holds true for the position of the proximal X-ray marker that may exist relative to the distal X-ray marker.

[0015] An embodiment of the method also provides that the protective device has at least one flexible membrane, the at least one contact element clamping the support, wherein the at least one membrane is between them to prevent contact between the support and the at least one contact element. The membrane can have, for example, PTFE or can consist of PTFE.

[0016] An embodiment of the method also provides that after the at least one membrane has been brought into contact with the support, the at least one membrane is moved such that the support, which is subsequently to be repositioned by the at least one contact element, comes into contact with a section of the at least one membrane which has not previously been in contact with the support.

[0017] An embodiment of the method also provides that at least one membrane is moved in an axial direction of the balloon catheter, or that the membrane is moved in a direction orthogonal to the axial direction.

[0018] One embodiment of the method also provides that at least one film is moved by unwinding the film from a feed roll and winding it onto a take-up roll.

[0019] One embodiment of the method also provides that, in order to reposition the stent relative to the balloon, the stent is moved in an axial direction relative to the balloon of the balloon catheter by a plurality of contact elements, and in order to reposition the stent, each of the contact elements clamps the stent, wherein an associated membrane (for example, made of PTFE) is between the contact element and the stent to prevent contact between the stent and the corresponding contact element, in particular, the corresponding contact element is moved away from the first position toward the balloon catheter to a second position so that the corresponding contact element reaches behind the face of the stent, wherein the associated membrane is therebetween, or in order to clamp the stent, the contact element presses against the stent (so as to clamp the stent, for example, at the middle or distal section of the stent), wherein the associated membrane is therebetween, in particular, in order to reposition the stent, the corresponding contact element located in the second position moves along the balloon catheter with the stent.

[0020] It is advantageous to reposition the stent by at least one contact element at the intermediate section of the stent, preferably at the distal section of the stent. The stent can be repositioned by pulling the stent in the distal direction, or by keeping the stent and pulling the balloon catheter in the proximal direction to reposition the stent in the distal direction of the catheter. Contrary to the compression that will occur when the stent is held by the contact element at the front side of the proximal section or the stent, such a repositioning mode causes the stretching of the stent when repositioning. The compression stent will cause the irreversible interlacing of the stent struts, which may damage the balloon during the subsequent curling process. Therefore, it is beneficial to reposition in a manner that causes the stretching of the stent, because the catheter abandonment caused by the defect can be reduced, which is further cost-effective.

[0021] In this case, the respective film can also be displaced after the contact with the support, so that the support to be subsequently repositioned comes into contact with a section of the respective film which was not previously in contact with the support.

[0022] The corresponding film can be moved in the axial direction of the balloon catheter, or in a direction orthogonal to the axial direction. In addition, the corresponding film can be moved again by unwinding the corresponding film from a feed roll and rolling it onto a take-up roll.

[0023] An embodiment of the method also provides that the distance is monitored with a camera. Alternatively, a capacitive sensor or an inductive sensor may be used.

[0024] The output signal of the camera or sensor can be used to control the movement of at least one of the support or multiple contact elements in the axial direction by open-loop control or closed-loop control. Here, it is advantageous if at least one or more contact elements move and the balloon catheter remains stationary (i.e., if it is static). If a camera is used, the distance between the support and the X-ray marker can be calculated, for example, from the number of pixels between the feature support and the X-ray marker recognized by the camera, calculated by multiplying the number of pixels by the "mm / pixel" value known from the camera calibration. The distance between the marker and the support, defined in this way as the actual distance, is compared with the expected distance. The difference determines the travel of the contact element, and thereby determines the travel of the support.

[0025] A preferred method of calculating the desired distance is by having a camera measure the distance of the X-ray markers from each other and the length of the stent.

[0026] Furthermore, before repositioning the stent, it is preferably pre-curled so that it has a defined directional offset so that when the stent is repositioned it only has to move in the opposite direction, which corresponds to the direction of movement of at least one contact element or multiple contact elements.

[0027] After repositioning the stent, it can be fixed in the final position by crimping it again onto the balloon of the balloon catheter.

[0028] One embodiment of the method also provides that the protective device is formed by a protective sheath arranged on and around the stent, and at least one contact element clamps the stent with the protective sheath therebetween to prevent contact between the stent and the at least one contact element. The protective sheath preferably covers the outer surface of the stent, and in particular the end or face of the stent.

[0029] One embodiment of the method also provides that, in order to reposition the stent relative to the balloon, the stent is moved in an axial direction relative to the balloon of the balloon catheter by a plurality of contact elements, and in order to reposition the stent, the contact elements clamp the stent with a protective sheath therebetween to prevent contact between the stent and the contact elements, in particular, the corresponding contact elements are moved away from the first position toward the balloon catheter to a second position so that the corresponding contact elements reach behind the surface of the stent with the protective sheath therebetween, or in order to clamp the stent, the contact elements are pressed against the stent with the protective sheath therebetween (so as to clamp the stent, for example, in the middle section of the stent), in particular, in order to reposition the stent, the corresponding contact elements located in the second position are moved along the balloon catheter with the protective sheath and the stent therewith.

[0030] An embodiment of the method also provides that the position of the support is determined by means of a capacitive or inductive sensor.

[0031] Capacitive or inductive sensors are particularly preferred when a protective sheath is used as the protective device. Assuming that the stent within the protective sheath cannot be visually detected, the capacitive or inductive sensor provides a means of identifying the position of the stent within the protective sheath. A camera cannot be used in this case. Therefore, for the method proposed herein, a capacitive or inductive sensor is preferably provided when a protective sheath is used.

[0032] One embodiment of the method further provides that, before the stent is moved in the axial direction, the balloon catheter is moved in the axial direction until the sensor detects the aforementioned X-ray marker and the aforementioned end of the stent. Alternatively, the sensor can also be moved until it detects the aforementioned X-ray marker and the aforementioned end of the stent. That is, only after this detection, in order to reposition the stent, the stent is moved in the axial direction until the distance from the end of the stent to the X-ray marker in the axial direction corresponds to the predetermined distance.

[0033] Here again, before repositioning the stent, the stent is preferably pre-curled so that it has a defined directional offset so that when repositioning the stent it only has to move in the opposite direction, which corresponds to the direction in which at least one contact element or multiple contact elements move.

[0034] After repositioning the stent, the stent can be re-secured in the final position by crimping it again onto the balloon of the balloon catheter.

[0035] Another aspect of the present invention relates to a device for repositioning a drug-coated stent, which is pre-curled on a balloon of a balloon catheter extending in an axial direction so that the inner surface of the stent abuts against the outer surface of the balloon, the device having at least one contact element, which is configured to move the stent in an axial direction relative to the balloon of the balloon catheter so as to reposition the stent relative to the balloon, and in order to reposition the stent, the at least one contact element is configured to clamp the stent, wherein a protective device is used therebetween to prevent contact between the stent and at least one contact element.

[0036] One embodiment of the device provides that, if the balloon catheter is arranged in the desired manner relative to at least one contact element, the at least one contact element is configured to move away from a first position toward the balloon catheter to a second position so that the at least one contact element reaches behind the surface of the stent with the protective device in between, or in order to clamp the stent, the contact element is pressed against the stent with the protective device in between.

[0037] An embodiment of the device also provides that, in order to reach behind the support, at least one contact element has a tapered end section.

[0038] Furthermore, in order to reposition the stent, at least one contact element is preferably designed such that if it is in the second position, it moves in the axial direction along the balloon catheter in order to move the stent along with it (if the balloon catheter is fixed with respect to the axial direction).

[0039] One embodiment of the device also provides that, to reposition the stent, the device is configured to move the stent in an axial direction until a distance in the axial direction from one end of the stent to an X-ray marker disposed on the balloon catheter corresponds to a predetermined distance.

[0040] A further embodiment of the device provides that the protective device has at least one membrane and that the at least one contact element is designed as a clamping support with the at least one membrane therebetween to prevent contact between the support and the at least one contact element.

[0041] One embodiment of the device also provides that the at least one membrane is designed to move after contact with the stent so that the stent to be subsequently repositioned comes into contact with a section of the at least one membrane which has not previously been in contact with the stent.

[0042] One embodiment of the device provides that the at least one membrane is configured to move in an axial direction of the balloon catheter or in a direction orthogonal to the axial direction.

[0043] One embodiment of the device also provides that the device for moving at least one film has a feed roller and a take-up roller, at least one film can be unwound from the feed roller, and at least one film can be rolled onto the take-up roller. This can also be achieved by moving the contact element.

[0044] Another embodiment of the inventive device provides that the device is configured to move a stent in an axial direction relative to the balloon of a balloon catheter by means of a plurality of contact elements so as to reposition the stent relative to the balloon, each of the contact elements for repositioning the stent being configured to clamp the stent, wherein each of the contact elements has a membrane of the device between it and the stent to prevent contact between the stent and the contact elements, in particular, when the balloon catheter is arranged in the manner it should be relative to the contact elements, the corresponding contact element is designed to move away from the first position toward the balloon catheter to a second position so that the corresponding contact element reaches behind the face of the stent, wherein the membrane of the device is therebetween, or in order to clamp the stent, the contact element presses against the stent, wherein a protective device is therebetween, in particular, in order to reposition the stent, the corresponding contact element located in the second position is designed to move so as to move with the stent (if the balloon catheter is fixed relative to the axial direction).

[0045] An embodiment of the device also provides that the device has a camera to monitor the aforementioned distance between the end of the stent and the X-ray marker. Instead of a camera, an inductive or capacitive sensor can be used, especially when the position of the stent cannot be determined visually, for example if the field of view of the stent is blocked.

[0046] An alternative embodiment of the device also provides that the protective device is formed by a protective sheath to be arranged on and around the stent, and at least one contact element is configured to clamp the stent, wherein when the protective sheath is arranged in the desired manner relative to the stent, the protective sheath is therebetween to prevent contact between the stent and the at least one contact element.

[0047] One embodiment of the device also provides that, in order to reposition the stent, the contact element is configured to clamp the stent, wherein when the protective sheath is arranged on the stent in the manner it should be, the protective sheath is between the contact element and the stent to prevent contact between the stent and the contact element, in particular, when the balloon catheter is arranged in the manner it should be relative to the contact element, the corresponding contact element is designed to move away from the first position toward the balloon catheter to a second position so that the corresponding contact element reaches behind the surface of the stent, with the protective sheath in between, or in order to clamp the stent, the contact element is pressed against the stent, with the protective device in between, in particular, in order to reposition the stent, the corresponding contact element located in the second position is designed to move so as to move with the stent (if the balloon catheter is fixed relative to the axial direction).

[0048] One embodiment of the device also provides that the means for determining the distance between the end of the stent and the X-ray marker has a capacitive or inductive sensor (especially if a protective sheath is used).

[0049] Capacitive or inductive sensors are particularly preferred when a protective sheath is used as the protective device. Assuming that the stent inside the protective sheath cannot be visually detected, the capacitive or inductive sensor provides a means of identifying the position of the stent inside the protective sheath. A camera cannot be used in this case. Therefore, for the device proposed herein, when a protective sheath is used, the device preferably comprises a capacitive or inductive sensor.

[0050] One embodiment also provides that the device is designed to move the balloon catheter in an axial direction relative to the sensor until the sensor detects the aforementioned X-ray marker and the aforementioned end of the stent, and to do so before the stent is moved in the axial direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The following uses the accompanying drawings to explain exemplary embodiments of the present invention as well as the features and advantages of the present invention. The accompanying drawings are as follows:

[0052] Figure 1An embodiment of the inventive method or the inventive device for repositioning a drug-coated stent relative to a balloon of a balloon catheter, wherein direct contact between the contact element and the stent is prevented by a membrane;

[0053] Figure 2 Figure 1 A variation of the embodiment of the method or apparatus for repositioning a drug coated stent as shown in;

[0054] Figure 3 Schematic illustration of the arrangement of contact elements and membranes relative to each other or relative to a support to be repositioned;

[0055] Figure 4 Figure 3 A variation of the arrangement shown in ;

[0056] Figure 5 A schematic cross-sectional view of two contact elements facing each other in a plane perpendicular to the axial direction of the balloon catheter;

[0057] Figure 6 according to Figure 5 Another schematic cross-sectional view of a contact element;

[0058] Figure 7 A schematic illustration of an embodiment of the method or the device, wherein the support is clamped or held in between by contact elements; and

[0059] FIG. 8 is a schematic illustration of an alternative embodiment of the inventive method or the inventive device, wherein here the drug-coated stent is protected from direct contact with the contact element by a protective sheath. DETAILED DESCRIPTION

[0060] Figures 1 to 7 Different embodiments of the method or device for repositioning a drug-coated stent 2 are shown, the stent 2 being pre-crimped on a balloon 30 of a balloon catheter 3. The stent 2 may have a circumferential wall structure (not shown in detail here), which is formed by, for example, a plurality of struts connected to each other, so that the wall structure has a plurality of cells bordered by the struts. The balloon catheter 3 preferably has X-ray markers 31, 32 so that the position of the balloon catheter 3 can be determined during implantation.

[0061] Prior to such a repositioning method, the stent 2 is guided (e.g., by a delivery system) to a pre-crimping head or tool. The position of the stent 2 in the head is defined, for example, by a mechanical stop. The balloon catheter 3 is then moved into the head and through the stent 2. The position of the stent 2 relative to the X-ray markers 31, 32 is now roughly defined by the travel path of the catheter 3. The stent 2 is preferably positioned with an offset to the proximal side. The stent 2 is then pre-crimped on the balloon 30 so that the inner surface 2a of the stent 2 is tightly against the outer surface 30b of the balloon 30, yet the stent 2 can still move relative to the balloon 30. In addition, the stent 2 has an outer surface 2b away from the inner surface 2a, and the drug coating on the outer surface 2b must be protected from cross contamination.

[0062] For example, from Figure 1 As can be seen, one embodiment of the inventive method provides that at least one contact element, in this case for example two contact elements 40, 41, moves the stent 2 relative to the balloon 30 in the axial direction z of the balloon catheter 3 in order to reposition the stent 2 in a defined manner. It is provided here that, in order to reposition the stent 2, the contact elements 40, 41 clamp the stent 2 with at least one flexible membrane (which can be composed of PTFE, for example) between each contact element 40, 41 and the stent to prevent direct contact between the stent 2 and the respective contact element 40, 41.

[0063] In order to move or reposition the support 2, the contact elements 40, 41 (see Figure 1 ) first move towards each other until they reach behind the face 2c of the stent 2. Then, the contact elements 40, 41 move downwards in the axial direction z, touching the face 2c of the stent 2 with the membranes 60, 61 between them and taking the stent 2 along with them, so that the stent is moved into a final position defined relative to the balloon 30. The corresponding distance between the stent end 2d and the distal X-ray marker 31 can be monitored by the camera 4 (or by an inductive or capacitive sensor).

[0064] Figure 2 Shows Figure 1 A variation of the arrangement shown in Figure 1 In contrast, the contact elements 40 , 41 have tapered end sections 40 a , 41 a in order to reach behind the support 2 .

[0065] As from Figures 1 to 7 It can also be seen that it is preferably provided that after the corresponding membrane 60, 61, 62 contacts the bracket 2, the membrane 60, 61, 62 moves so that the bracket to be repositioned subsequently contacts the section of the corresponding membrane 60 that has not previously been in contact with the bracket 2, so that cross contamination of the bracket 2 is prevented in a simple manner.

[0066] Figure 3 and Figure 4 The embodiment shown provides that the respective membrane 60 , 61 , 62 is moved in the axial direction z of the balloon catheter 3 . Figure 3 An embodiment is shown with three contact elements 40 , 41 , 42 which can be moved in the direction towards the catheter 3 to reach behind the face 2 c of the support 2 with the respective membrane 60 , 61 , 62 therebetween. Figure 4 A plurality of contact elements are shown, which abut against each other in the peripheral direction of the support 2, forming a structure surrounding the support 2 in the peripheral direction or surrounding the support 2 in the cross section. Each of the three contact elements 40, 41, 42 is covered with a membrane 60, 61, 62, which, when the contact elements move toward each other, approach each other, and ultimately result in no contact element being able to make direct contact with the support 2, but only reaching behind the support or clamping the support 2 with the membrane 60, 61, 62 between them (see Figure 7 ).

[0067] also, Figure 5 and Figure 6 An embodiment is shown in which the respective membrane 60, 61 moves in a direction orthogonal to the axial direction z. Here, for example, the respective membrane 60, 61 can be turned around the edge 40b, 41b of the contact element 40, 41 under consideration so that the edge 40b, 41b can be used to reach behind the support 2 (see Figure 6 ).

[0068] In order to move the respective film 60, 61, 62, it can be provided that the respective film 60, 61, 62 is unwound from the feed roller 600 and rolled onto the take-up roller 601. This can involve the respective take-up roller 601 being rotated or driven by a drive. In addition, the film can also be unwound by moving the contact element. Such a sequence of events can be supported, for example, by a spring ratchet system.

[0069] Instead of the contact elements 40, 41 and 42 reaching behind the support 2, these contact elements 40, 41 and 42 can also be designed to clamp, for example, the middle section 2e of the support 2 (the corresponding membrane 60, 61, 62 is located between them), such as Figure 7 shown.

[0070] After the stent 2 has been repositioned, the stent 2 can be fixed in the final position by crimping it again onto the balloon 30 of the balloon catheter 3 .

[0071] Furthermore, FIG. 8 shows an alternative embodiment of the inventive method or the inventive device, wherein here cross contamination of the drug-coated stent 2 is avoidable by encapsulating the stent 2 in a protective sheath 70 to protect the stent 2 from direct contact with the contact elements 40 , 41 .

[0072] The aforementioned encapsulation should preferably be maintained throughout the entire process chain (in particular, delivering the stent, mounting the stent on the balloon, pre-crimping the stent, repositioning the stent, crimping the stent, embedding the stent) in order to avoid additional process steps for removing the encapsulation or the protective sheath 70 .

[0073] As shown in Figure 8(A), it is provided that the corresponding contact elements 40, 41 move away from the first position toward the balloon catheter 3 to the second position, so that the corresponding contact elements 40, 41 reach behind the surface 2c of the stent 2, with the protective sheath 70 therebetween, or opposite to the stent 2 in the axial direction z (see Figure 8(B)).

[0074] Then, the contact elements 40, 41 are moved in the axial direction z relative to the balloon 30 of the balloon catheter 3, the contact elements 40, 41 touch the stent with the protective sheath 70 between them, and the contact elements 40, 41 move the stent to its final position (see FIG. 8(C)). Thereafter, the catheter 3 can be removed from the contact elements 40, 41 (see FIG. 8(D)). Such movement can also be achieved by a system in which the contact elements 40 and 41 can be designed to clamp, for example, an intermediate section with the protective sheath 70 between them, similar to Figure 7 The system shown in .

[0075] As the stent 2 moves, the distance A between the stent end 2 d and the distal X-ray marker 31 is monitored, preferably by a capacitive or inductive sensor 5 .

[0076] Preferably, this involves first fixing the catheter 3 so that it can only move in the axial direction z in order to receive a sensor signal that is as stable as possible. Thereafter, the balloon catheter 3 is moved in the axial direction z or the sensor 5 is moved until the X-ray marker 31 (in particular its proximal edge) and the distal stent end 2d are detected. The balloon catheter 3 is then fixed in the axial direction z. Thereafter, the contact elements 40, 41 perform the above-mentioned repositioning of the stent 2 in the axial direction z until the distance A between the stent end 2d and the X-ray marker 31 reaches the desired value (the distance between the two X-ray markers 31, 32 and the length of the stent 2 in the axial direction z are known).

[0077] The present application advantageously allows for machine repositioning of the pre-crimped drug coated stent 2 and prevents contamination thereof during the process.

[0078] The inductive or capacitive sensor 5 makes it possible to avoid the sensitivity to errors of the optical detection which must be carried out in the presence of a protective sheath, in particular in the case of an opaque protective sheath. For example, contamination on the balloon 30 may lead to optical measurement errors. In addition, the balloon folds of the balloon 30 are located near the X-ray markers 31, 32 and they may lead to reflections which may make the optical detection of the markers 31, 32 difficult. Therefore, the non-optical detection by the inductive or capacitive sensor 5 is advantageous even for non-encapsulated stents 2.

Claims

1. A method for repositioning a drug-coated stent (2), the drug-coated stent (2) being pre-crimped on a balloon (30) of a balloon catheter (3) extending in an axial direction (z), so that an inner surface (2a) of the stent (2) abuts against an outer surface (30b) of the balloon (30), the method comprising the following steps: - By means of at least one contact element (40, 41, 42), the stent (2) is moved in the axial direction (z) relative to the balloon (30) of the balloon catheter (3) to reposition the stent (2) relative to the balloon (30) and reposition the stent (2), wherein the at least one contact element (40, 41, 42) clamps the stent (2) at the middle section or distal section of the stent (2), wherein a protective device (60, 61, 62; 70) is between the at least one contact element (40, 41, 42) and the stent (2) to prevent contact between the stent (2) and the at least one contact element (40, 41, 42).

2. The method according to claim 1, wherein: The at least one contact element (40, 41, 42) is moved away from the first position toward the balloon catheter (3) to a second position such that the at least one contact element (40, 41, 42) reaches behind the surface (2c) of the stent (2), wherein the protective device (60, 61, 62; 70) between the at least one contact element (40, 41, 42) and the surface (2c) of the support (2), or in order to clamp the support (2), the contact element is pressed against the support (2), wherein the protective device (60, 61, 62; 70) between the contact element and the bracket (2).

3. The method according to claim 2, wherein: The at least one contact element (40, 41, 42) has a tapered end section (40a, 41a) to reach behind the support (2).

4. The method according to claim 2 or 3, wherein: In order to reposition the stent (2), the at least one contact element (40, 41, 42) located in the second position moves along the balloon catheter (3) in the axial direction (z) with the stent (2), and the balloon catheter (3) is fixed relative to the axial direction (z).

5. The method according to any one of claims 1 to 3, wherein: To reposition the stent (2), the stent (2) is moved in the axial direction (z) until the distance (A) from one end (2d) of the stent (2) to an X-ray marker (31) arranged on the balloon catheter (3) in the axial direction (z) corresponds to a predetermined distance.

6. The method according to any one of claims 1 to 3, wherein: The protective device comprises at least one membrane (60, 61, 62), and the at least one contact element (40, 41, 42) clamps the bracket (2), wherein the at least one membrane (60, 61, 62) is between the at least one contact element (40, 41, 42) and the bracket (2) to prevent contact between the bracket (2) and the at least one contact element (40, 41, 42).

7. The method according to claim 6, wherein: After the at least one membrane (60, 61, 62) comes into contact with the support (2), the at least one membrane (60, 61, 62) is moved so that the support to be subsequently repositioned comes into contact with a section of the at least one membrane (60, 61, 62) that has not previously come into contact with the support.

8. The method according to claim 7, wherein: The membrane (60, 61, 62) moves in the axial direction (z) of the balloon catheter (3), or the membrane (60, 61, 62) moves in a direction orthogonal to the axial direction (z).

9. The method according to claim 7, wherein: The at least one film (60, 61, 62) is moved by unwinding the at least one film (60, 61, 62) from a feed roll (600) and winding it onto a take-up roll (601).

10. The method according to any one of claims 1 to 3, wherein: In order to reposition the stent (2) relative to the balloon (30), the stent (2) is moved in the axial direction (z) relative to the balloon (30) of the balloon catheter (3) by a plurality of contact elements (40, 41, 42), and in order to reposition the stent (2), each of the contact elements (40, 41, 42) clamps the stent (2), wherein a membrane (60, 61, 62) is between the contact elements and the stent (2) to prevent contact between the stent (2) and the contact elements (40, 41, 42).

11. The method according to claim 10, wherein: The corresponding contact element (40, 41, 42) is moved away from the first position toward the balloon catheter (3) to a second position so that the corresponding contact element (40, 41, 42) reaches behind the surface (2c) of the support (2), wherein the membrane (60, 61, 62) is between the corresponding contact element (40, 41, 42) and the surface (2c) of the support (2), or so that in order to clamp the support (2), the contact element is pressed against the support (2), wherein the membrane (60, 61, 62) is between the contact element and the support (2).

12. The method according to claim 11, wherein: In order to reposition the stent (2), the corresponding contact element (40, 41, 42) located in the second position is moved along the balloon catheter (3) carrying the stent (2) together with it.

13. The method according to any one of claims 1 to 3, wherein: The protective device is formed by a protective sheath (70) arranged on the bracket (2) and surrounding the bracket (2), and the at least one contact element (40, 41, 42) clamps the bracket (2), wherein the protective sheath (70) is between the at least one contact element (40, 41, 42) and the bracket (2) to prevent contact between the bracket (2) and the at least one contact element (40, 41, 42).

14. The method according to claim 13, wherein: In order to reposition the stent (2) relative to the balloon (30), the stent (2) is moved in the axial direction (z) relative to the balloon (30) of the balloon catheter (3) by a plurality of contact elements (40, 41, 42), and in order to reposition the stent (2), the contact elements (40, 41, 42) clamp the stent (2), wherein the protective sheath (70) is between the contact elements and the stent to prevent contact between the stent (2) and the contact elements (40, 41, 42).

15. According to the method according to claim 14, the corresponding contact element (40, 41, 42) is moved away from the first position toward the balloon catheter (3) to the second position, so that the corresponding contact element (40, 41, 42) reaches behind the surface (2c) of the bracket (2), wherein the protective sheath (70) is between the corresponding contact element (40, 41, 42) and the surface (2c) of the bracket (2), or in order to clamp the bracket (2), the contact element is pressed against the bracket (2), wherein the protective sheath (70) is between the contact element and the bracket (2).

16. The method according to claim 15, wherein the corresponding contact element (40, 41, 42) located at the second position is moved along the balloon catheter (3) with the protective sheath (70) and the stent (2) therewith in order to reposition the stent (2).

17. The method according to claim 5, wherein: The distance is monitored with a camera (4) or with a capacitive sensor or with an inductive sensor.

18. The method according to claim 17, wherein: Before the stent (2) moves in the axial direction (z), the balloon catheter (3) moves in the axial direction (z) relative to the capacitive sensor or the inductive sensor until the capacitive sensor or the inductive sensor detects the aforementioned X-ray marker (31) and the aforementioned end (2d) of the stent (2).

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