Arrangement for feeding a medical implant, wire and catheter

Abstract

The invention relates to an arrangement for feeding a medical implant into a hollow organ of the body comprising a wire (10) and a compressible and expandable medical implant (11) which is in the form of a tube, - wherein the implant (11), in the compressed state, is releasably connected to the wire (10) by at least one engagement element (12) for the transfer of force in the axial direction, wherein the engagement element (12) has at least one projection (13) which extends radially outwardly and engages in the implant (11), and - wherein the implant (11), in the at least partially expanded state, can be released by a relative movement between the engagement element (12) and the implant (11) in a release direction, characterised in that the engagement element (12) has at least one sliding surface (14) which is inclined and / or curved in the release direction and interacts with the projection (13) to release the implant (11).

Description

[0001] Arrangement for delivering a medical implant, wire and catheter

[0002] Description

[0003] The invention relates to an arrangement for delivering a medical implant into a hollow body organ, comprising a wire and a compressible and expandable medical implant that is tubular in shape. In the compressed state, the implant is releasably connected to the wire by at least one engagement element for transmitting force in the axial direction, wherein the engagement element has at least one projection that extends radially outward and engages the implant. In the at least partially expanded state, the implant can be released in a release direction by a relative movement between the engagement element and the implant. The invention further relates to a wire for delivering a medical implant into a hollow body organ and to a catheter.

[0004] The arrangement mentioned above is known, for example, from WO 2013 / 107783 A1, which originates from the applicant. A wire having the features of the preamble of claim 14 is also known from this prior art.

[0005] This arrangement, or rather, this wire, has proven extremely effective in practice and enables the safe delivery of an implant, such as a stent or flow diverter, to the treatment site through a catheter. Upon release from the catheter, the implant is detached from the wire and remains at the treatment site. The wire is retracted through the catheter.

[0006] The implant is deployed by a relative axial movement between the catheter and the implant at the treatment site. The implant emerging from the catheter unfolds or expands, with the expansion movement progressively progressing proximal to the implant as the release progresses. As the implant expands in the area of ​​the engagement element, the radial outward movement releases the implant from the wire, and the implant and engagement element are separated. The implant is fully deployed and expanded at the desired location in the vessel to be treated.

[0007] If the radial outward movement of the implant is restricted, for example, by patient-specific vascular properties in the area of ​​the treatment site, so that the radial distance between the implant and the interventional element is small, the release of the implant can be made more difficult.

[0008] The invention is therefore based on the object of improving the known arrangement so that the implant can be released as safely as possible, even under difficult conditions. The invention is further based on the object of providing a corresponding wire and catheter.

[0009] According to the invention, the object is achieved with regard to the arrangement by the subject matter of claim 1, with regard to the wire by the subject matter of claim 14 and with regard to the catheter by the subject matter of claim 15.

[0010] Specifically, the problem is solved by an arrangement for introducing a medical implant into a hollow body organ, comprising a wire and a compressible and expandable medical implant that is tubular in shape. In the compressed state, the implant is releasably connected to the wire by at least one engagement element for transmitting force in the axial direction. The engagement element has at least one projection that extends radially outward and engages the implant. In the at least partially expanded state, the implant can be released by a relative movement between the engagement element and the implant in a release direction. According to the invention, the engagement element has at least one sliding surface that is inclined and / or curved in the release direction. The sliding surface interacts with the projection to release the implant.

[0011] The invention has the advantage that the engagement element and the implant can be safely released even when the distance between the engagement element and the implant is relatively small, because the implant can slide on the sliding surface during release, thereby assisting in the decoupling of the implant from the wire. Hooking of the implant with the engagement element is avoided, and the wire can be safely retracted into the catheter. This is achieved by the inclined and / or curved sliding surface.

[0012] The sliding surface interacts with the projection to release the implant. The sliding surface is therefore suitable or adapted to assist in the release of the implant. Advantageously, the sliding surface and the projection are formed as a single piece or monolithic component. It is also possible to form the sliding surface and the projection in two parts. In this case, the sliding surface and the projection are two separate components, e.g., two sleeves arranged axially directly one behind the other, although other embodiments are possible.

[0013] The projection and the sliding surface interact in that the sliding surface causes, or at least contributes to, the implant reaching the height required to overcome the projection. The height can, but does not have to, be the radial outer surface of the projection. The sliding surface and the projection are arranged in the axial direction of the implant or wire in such a way that a transition of movement of the implant is possible, e.g., if the sliding surface and the projection are connected or connectable, so that the sliding surface transitions directly into the projection. Other designs are possible.

[0014] Due to the inclination and / or curvature, the sliding surface extends in a direction deviating from a vertical side of the projection. Since the inclination or curvature runs in the release direction, the sliding surface assists the release process.

[0015] The release direction is the direction in which the implant is released by the relative movement between the engaging element or wire and the implant. For example, if the wire is retracted proximally into the catheter while the implant is still in place, the release direction of the implant is distal. The implant is located proximal to the catheter tip before release and distal to the catheter tip after release. The sliding surface is then also oriented distally, allowing the implant to slide along the sliding surface when the engaging element is moved proximal.

[0016] The release direction is not limited to the longitudinal direction of the implant.

[0017] Rather, the release direction generally refers to the relative movement between the engagement element and the implant, which occurs in addition to the expansion movement of the implant to disengage the implant and the engagement element in the radial direction. The release direction can be in the longitudinal direction of the implant or in the circumferential direction of the implant. Both alternatives are the subject of preferred embodiments of the invention, which are described in more detail below.

[0018] The sliding surface even allows the implant to be decoupled from the wire even in a partially expanded state, where the implant and the engaging element overlap, thus remaining partially engaged. This is achieved by tilting and / or curving the sliding surface in the release direction. When the wire is retracted proximally into the catheter, the implant slides on the sliding surface and is pushed radially outward. The implant is thus released from the wire.

[0019] The mechanism described above for the partially expanded state with partial engagement applies equally to a partially expanded state in which the radial distance between the engagement element and the implant is so small that engagement can occur upon release.

[0020] The invention is suitable for self-expanding medical implants. The medical implant of the arrangement can therefore be self-expanding. Such implants are known and are usually made of a shape-memory material.

[0021] The implant can preferably have a lattice structure, in particular a tubular wall made of a lattice structure. The lattice structure can be a mesh of braided filaments or wires, or of a braided single filament or wire. The mesh forms meshes. The lattice structure can also be a monolithic lattice structure made of webs, for example, a laser-cut lattice structure. The monolithic lattice structure forms cells.

[0022] The invention is not limited to a specific type of intervention. The wire can be connected to the implant in various ways. For example, the engagement element can engage the lattice structure. It is also possible for the engagement element to be detachably connected to end loops, end meshes, or end diamonds of the implant. Detachable connections between the implant and the engagement element can also be provided by additional components, in particular X-ray markers. These can be, for example, crimped marker sleeves.

[0023] The engagement element may have several projections. Each projection interacts with a sliding surface to release the implant.

[0024] The inventive arrangement comprising an implant and a wire is treated as an assembly that is disclosed and claimed independently of the catheter used to transport the arrangement to the treatment site. In addition, the combination of a catheter and the inventive arrangement is also disclosed and claimed. Within the scope of the invention, the wire for delivering the medical implant as such, i.e., without an implant and without a catheter, is also disclosed and claimed. The wire is suitable for achieving the advantages explained above in connection with the delivery of an implant and, for this purpose, has an engagement element modified according to the invention, which is described above. Such a wire is also referred to as a transport wire.

[0025] Preferred embodiments of the invention are claimed or specified in the subclaims.

[0026] The sliding surface can be inclined and / or curved in the longitudinal direction of the implant, particularly in the distal longitudinal direction. This embodiment has the advantage that the release direction runs parallel to the wire. This allows the wire to be retracted into the catheter during a relative movement between the axially moved wire and the stationary implant. This corresponds to the usual release process when the implant is anchored stationary at the treatment site and the wire is retracted in the proximal direction. The inclination of the sliding surface in the distal longitudinal direction means that a spatial component of the sliding surface runs in the distal direction. This is not the case with a surface orthogonal to the longitudinal axis of the wire.When the wire with the engagement element is pulled in the proximal direction, the sliding surface moves relative to the implant, resulting in a relative movement between the engagement element and the implant, which separates the engagement element and the implant from each other and prevents a further unwanted engagement.

[0027] Preferably, the inclined sliding surface comprises a chamfer formed at least in the region of the outer edge of the projection. The chamfer can be easily manufactured, since only the outer edge of the projection needs to be machined. It is not necessary to machine the entire side of the projection. It is sufficient if a portion of the projection is provided with the chamfer or is chamfered, specifically in the region of the outer edge of the projection, i.e., where snagging with the implant can occur if the distance between the engagement element and the implant is insufficient.

[0028] In another embodiment, the chamfer can be positioned at the base of the projection. The chamfer thus extends across the entire side of the projection. This has the advantage of creating a maximum-length sliding surface. Security against snagging is increased.

[0029] The engagement element can have a conical profile at least at one axial end with the correspondingly inclined projection, which forms the inclined sliding surface. This embodiment has the advantage that the engagement element including the projection is inclined, so that practically no edges are formed in the release direction that could hinder decoupling. This minimizes the risk of snagging. The projection and thus the sliding surface are part of the conical surface of the engagement element and are therefore inclined according to the conicity of the axial end of the engagement element. In a further preferred embodiment, the engagement element is curved in the axial direction of the implant, in particular in the distal direction of the implant, wherein the projection is formed on the outer curvature of the engagement element with a corresponding curvature and forms the curved sliding surface.This means that the entire engagement element, including the projection, is curved and therefore also has no edges that could hinder the release process. This minimizes the risk of snagging. The projection is part of the curved engagement element and is therefore also curved accordingly. The engagement element can, for example, be cut from a tube and profiled accordingly.

[0030] In another particularly preferred embodiment, the inclined and / or curved sliding surface comprises a tube that encloses the engagement element. This embodiment has the advantage of particularly simple and flexible production. Mechanical processing of the engagement element is eliminated. The tube can be, for example, a flexible tube or a shrink tube.

[0031] The sliding surface is created by an additional element, namely the hose, which is arranged over and encloses an engagement profile core. The hose, together with the engagement profile core, forms the engagement element—specifically, the projection(s) with the sliding surface. The encased engagement profile core forms the core of the hose and stabilizes it. The outer contour of the engagement element is determined by the shape of the hose.

[0032] For the engagement profile core, conventional engagement elements can be used, which are modified by combining them with the hose to create a projection or projections (depending on the engagement profile core) that have inclined and / or curved sliding surfaces through the hose. Manufacturing is therefore simple and can be carried out flexibly using conventional engagement elements.

[0033] The hose encloses the engagement element in a geometrically undefined manner. It is essentially adapted to the contour of the engagement element, i.e., it does not directly follow the contour and does not lie tightly against the engagement element. The outer edges of the engagement element are covered by the hose, which forms a rounded sliding surface or a rounded sliding surface section there. In the radially outer region of the engagement element, the hose lies more closely against the contour than in the radially inner region. The hose thus represents the rough contour of the engagement element. The sliding surface forms a flowing or continuous transition from the radial inside to the radial outside.

[0034] If several engagement elements are arranged on the circumference of the wire, the tube follows the resulting height profile in the circumferential direction so that the engagement elements can engage in the implant, e.g. in the lattice structure.

[0035] The tube forms the inclined and / or curved sliding surface by extending essentially at an angle, deviating from the vertical relative to the tubular shape of the implant or deviating from the vertical flank or side of the engagement profile core. Sections of the tube can be inclined and curved to varying degrees. Along its entire extension in the release direction, the tube forms an inclined freeform surface for releasing the implant. The freeform surface acts as a sliding surface.

[0036] In contrast, the chamfer forms a geometrically defined, particularly straight, sliding surface that is inclined. The basic idea is the same as with the chamfer or the curved shape of the engagement element: namely, by orienting the sliding surface in a direction deviating from the vertical, it supports the release process between the implant and the wire.

[0037] The hose can be flexible or compliant, such as a polymer hose. This flexibility allows the hose to stretch over the engagement profile core, adapting to its rough contour. Alternatively, the hose can be a shrink hose, which, through heat treatment or other treatment, stretches over the engagement profile core and thus adapts to its rough contour.

[0038] The shrink tube can be brought from an initial state into a compressed state, in particular by heat treatment. The ratio between the outer diameter of the tube in the initial state and the outer diameter of the tube in the compressed state is preferably between 2:1 and 6:1, in particular between 3:1 and 6:1, in particular between 4:1 and 6:1, in particular between 5:1 and 6:1. The outer diameter of the tube in the initial state is preferably at least twice as large, in particular at least three times as large, in particular at least four times as large, as the outer diameter of the tube in the compressed state.

[0039] The tube, in particular the shrink tube, is preferably made of plastic, for example, PTFE, PE, PVC, and / or FEP. Other materials are possible. In particular, the tube is made of a material that allows a ratio of 2:1 to 6:1 between the outer diameter of the tube in its initial state and the outer diameter of the tube in its compressed state.

[0040] The thickness of the tube, in particular the shrink tube, or the thickness of the tube in the radial direction, is preferably between 20 pm and 200 pm, in particular at least 50 pm, in particular at least 100 pm, in particular at least 150 pm. A different thickness of the tube is conceivable.

[0041] Alternatively or additionally, the length of the projection in the radial direction of the engagement element can be at least 1.5 times, in particular at least 2 times, in particular at least 2.5 times, the thickness of the tube, in particular of the shrink tube, or the thickness of the tube in the radial direction.

[0042] It is possible for several engagement elements to be arranged at a distance from one another on the transport wire. The engagement elements can have a different outer diameter and / or be spaced from one another by intermediate elements that have a different outer diameter than the engagement elements. The inner diameter of the shrink tube is preferably designed such that it can be adapted to the outer diameter of all engagement elements and / or intermediate elements arranged on the transport wire, or to the transport wire itself, even if the engagement elements, intermediate elements, and the transport wire have different outer diameters. It is possible for several tubes, in particular several shrink tubes, to be arranged on the transport wire. The number of engagement elements and the number of shrink tubes can be the same or different.For example, it is possible for a hose to extend over all engagement elements. Alternatively, one hose can be provided for each engagement element.

[0043] The shrink tubing is advantageously adaptable to the contour of the engagement element in such a way that the shrink tubing does not directly follow the contour and does not fit tightly against the engagement element. This is preferably understood to mean that gaps are created between the engagement element and the shrink tubing. Such gaps can be filled with UV and / or heat-curing adhesive.

[0044] In a further embodiment of the invention, the sliding surface is inclined and / or curved in the circumferential direction of the implant. This ensures that the release process is actively supported by rotating the wire. Rotating the wire results in a relative movement between the implant and the engagement element in the circumferential direction. The implant slides circumferentially on the sliding surface and is pushed radially outwards by the inclination or curvature. If the distance between the implant and the engagement element is too small due to insufficient expansion movement and an overlap occurs, the physician can force the decoupling by rotating the wire. Once the implant and the wire are disengaged due to the rotation, the wire can be retracted proximally into the catheter as usual.

[0045] It is possible to combine embodiments in which the sliding surface is inclined and / or curved in the circumferential direction and in the longitudinal direction of the implant. For example, the sliding surface can be arranged spirally with increasing diameter. This results in a screw effect in which the engagement element rotates and simultaneously executes a feed movement relative to the implant. The height of the implant and, at the same time, the relative position between wire and implant in the axial direction are changed. In a further embodiment, it is possible for several, in particular two, engagement elements to be arranged axially spaced from one another, each with at least one sliding surface in the longitudinal direction of the wire, wherein the sliding surfaces of the engagement elements are oriented in the same direction. This increases the security when coupling the implant to the wire through the multiple connection. The release functionality is retained.For this purpose, the sliding surfaces are provided on both engagement elements and oriented in the same direction so that they support the release process in the event of a relative movement between the wire and the implant in the same direction.

[0046] A proximal stop (also called a pushing sleeve) can be assigned to the engagement element, which is arranged axially spaced from the engagement element in the longitudinal direction of the wire, forming a free space. This basic structure of the arrangement is designed to accommodate an additional component, e.g., an X-ray marker, and is described in the aforementioned prior art publication, but with the difference that the engagement element is modified in the present case for easier release. This embodiment can be combined with all other embodiments or examples of this application and is also disclosed and claimed in this combination.

[0047] Preferably, the engagement element has a plurality of projections distributed around the circumference of the engagement element, each having at least one sliding surface and forming an engagement section. This improves the security of the connection and ensures uniform force transmission from the wire to the implant across the circumference of the engagement element. The sliding surfaces of the projections are each oriented in the same direction. This does not preclude the provision of additional sliding surfaces oriented in other directions.

[0048] The engagement element can have multiple engagement sections in the longitudinal direction of the wire, wherein the projections of the various engagement sections are arranged offset in the circumferential direction. This improves both the coupling security due to the increased number of projections and the uniform force transmission because the projections of the various engagement sections are arranged offset in the circumferential direction. The projections of a first engagement section can have sliding surfaces at least in the proximal direction, and the projections of a second engagement section can have sliding surfaces at least in the distal direction. The engagement element therefore enables a release process in both axial directions. This can be advantageous if the decoupling of the implant is to be particularly strongly supported by an axial movement of the wire and thus of the engagement element.

[0049] In general, each projection engages in its own mesh or cell of the grid structure.

[0050] The invention will be explained in more detail below using exemplary embodiments with reference to the accompanying drawings.

[0051] Fig. 1 is a perspective view of an arrangement according to an embodiment of the invention with two engagement elements (without implant);

[0052] Fig. 2 is a perspective view of an engagement element for an arrangement according to Fig. 3;

[0053] Fig. 3 is a view of an arrangement according to a further embodiment of the invention with an engagement element and a stop (without implant);

[0054] Fig. 4 is a side view of the engagement element according to Fig. 3;

[0055] Fig. 5 is a perspective view of an engagement element of an arrangement according to a further embodiment of the invention with a plurality of engagement sections;

[0056] Fig. 6 is a perspective view of an engagement element of an arrangement according to a further embodiment of the invention with two engagement sections; Fig. 7 is a perspective view of an engagement element of an arrangement according to a further embodiment of the invention with rounded sliding surfaces;

[0057] Fig. 8 is a perspective view of an arrangement according to a further embodiment of the invention with a stocking tube (without implant);

[0058] Fig. 9 is a side view of an arrangement with the engagement element according to claim 8 (without implant);

[0059] Fig. 10 is a front view of an arrangement according to a further embodiment of the invention, in which the release direction runs in the circumferential direction of the implant;

[0060] Fig. 11 the arrangement according to Fig. 10 during release of the implant;

[0061] Fig. 12 is a perspective view of an engagement element for an arrangement according to Fig. 1 and

[0062] Fig. 13 is a perspective view of an engagement element for an arrangement according to Fig. 3 with a greater curvature than Fig. 2.

[0063] Fig. 1 shows an embodiment of an arrangement according to the invention for introducing a medical implant 11 into a hollow body organ, which is particularly, but not exclusively, suitable for the treatment of neurovascular diseases, such as, for example, stroke treatment.

[0064] The arrangement comprises a wire 10, which can also be referred to as a transport wire or a holding wire, and the implant 11. The arrangement of wire 10 and implant 11 forms an assembly that is preloaded in a catheter (not shown). The assembly is disclosed and claimed within the scope of the application, as is the wire 10 without the implant 11. In addition, the combination of catheter and arrangement or assembly is disclosed and claimed, which usually forms the economic unit that is placed on the market. The implant 11 is tubular and compressible and expandable in a manner known per se in order to be transported through the catheter to the lesion to be treated. The implant 11 is preferably self-expandable. This can usually be achieved by making the implant 11 from a shape memory material, such as nitinol.The invention is not limited to specific implant materials. Other implant materials are possible.

[0065] The tubular implant 11, specifically its wall, is formed from a lattice structure. The lattice structure can be designed as a mesh or as a monolithic lattice structure. Reference is made to the explanations in the introduction to the description of the application. Examples of such implants are stents or flow diverters. Other implants 11 are possible that can be detachably connected to the wire 10.

[0066] The wire 10 is designed in a conventional manner and comprises, for example, coils arranged on a core (see Fig. 3). Other designs of the wire 10 are possible.

[0067] In the pre-loaded state, i.e. in the catheter, the implant 11 is compressed and detachably connected to the wire 10. For this purpose, the arrangement according to Fig. 1 comprises several, specifically two, engagement elements 12 which engage in the lattice structure of the implant 11 in order to thereby effect a force transmission in the axial direction from the wire 10 to the implant 11. The connection between the wire 10 and the implant 11 is detachable in order to decouple the implant 11 from the wire 10 when the implant 11 is released from the catheter at the treatment site. In the at least partially expanded state, the implant 11 can be released by a relative movement between the engagement elements 12 and the implant 11 in a release direction.

[0068] The relative movement between the engagement elements 12 and the implant 11 must be distinguished from the radial expansion of the implant 11, in which the implant 11 moves radially outwards. The implant 11 is initially detached from the wire 10 and its engagement element 12 by the radial expansion and then finally decoupled by a further movement of the wire 10 relative to the implant 11. The relative movement thus occurs when the wire 10 is moved relative to the implant. The relative movement occurs in the longitudinal direction of the implant and / or in the circumferential direction of the implant 11. In the examples according to Figures 1 to 9, the relative movement occurs in the longitudinal direction of the implant 11. In the examples according to Figures 10, 11, the relative movement occurs at least initially in the circumferential direction of the implant 11. A combination is possible. This will be explained in more detail below.

[0069] The engaging element 12, or the two engaging elements 12, which are modified for safe detachment from the implant 11, are described in more detail below with reference to Figures 1 and 12.

[0070] In Fig. 1, both engagement elements 12 are essentially identical in design. Deviations are due to manufacturing processes. Other combinations are possible. The following explanations apply to both engagement elements 12.

[0071] The engagement element 12 is sleeve-shaped. This also applies to the exemplary embodiments according to Figures 3 to 11. The engagement element 12 has a central opening through which the wire 10, specifically the core of the wire 10, extends in the installed state. This is clearly visible in Figures 1 and 3. The engagement element 12 can be connected to the wire 10 in a rotatable or rotationally fixed manner.

[0072] The engagement element 12 has several, specifically three, projections 13 that extend radially outward. The function of these projections 13 is to engage the implant 11, specifically the lattice structure of the implant 11, when the implant 11 is arranged in the compressed state on the wire 10. The projections 13 can also be referred to as the points of a crown, as noses, wings, or teeth. A different number of projections 13, in particular more than three projections 13, is possible.

[0073] The projections 13 each have a sliding surface 14 in the form of a chamfer 15, which is inclined in the release direction. In the example according to Fig. 1, the sliding surfaces 14 of the two engagement elements 12 are inclined in the same direction.

[0074] The release direction results from the relative movement between the

[0075] The engagement element 12 or the wire 10 and the implant 11 when the implant 11 is released. For the release direction, please refer to the explanations and definitions in the introduction to the description.

[0076] In the example according to Fig. 1, the bevels 15 are inclined in the distal direction (from right to left in Fig. 1). In other words, the distance between the sliding surface 14 and the wire 10 increases in the distal direction. The bevels 15 or the sliding surfaces 14 form essentially straight surfaces and act as bevels on which the implant 11, specifically its lattice structure, can slide if the implant 11 overlaps with the engagement elements 12 during release. The wire 10 can thus be pulled further in the proximal direction without the implant blocking the movement. Rather, the implant 10 is pushed radially outward by the inclined sliding surfaces 14 and is released from the engagement element 12.

[0077] As can be seen in Fig. 12, the entire proximal end face of the engagement element 12, including the inner ring 20 on which the projections 13 are arranged, is inclined. The engagement element 12 thus has a conical profile at its proximal axial end with correspondingly inclined projections 13. This profile can also be described as frustoconical. The sliding surface 14 begins at the level of the wire 10 and continues to the outer edge of the respective projection 13, which is formed on the outer diameter of the conical profile. Following the conical profile, the engagement element 12 continues with a cylindrical body (inner ring 20) and the toothed outer profile, as shown in Figures 1 and 12.

[0078] The sliding surface 14 has at least two sections: a first common sliding surface section 14a in the region of the end face of the inner ring 20 and a second sliding surface section 14b, which forms the transition from the inner ring 20 to the projection 13. Both sections 14a, 14b merge into one another.

[0079] The projections 13 and sliding surface 14 can be formed in one piece, as shown in Fig. 1, 12. Alternatively, the engagement element 12 can be formed in two parts. The first common sliding surface section 14a can be formed as a separate sleeve that rests against the end face of the inner ring 20. The transition between the two sections 14a, 14b corresponds to Fig. 12. Alternatively, only the proximal end face of the projection 13 can be formed as a sliding surface 14. The sliding surface 14 starts at the base of the projection 13, i.e., at the outer diameter of the inner ring 20. The end face of the inner ring 20 is vertical.

[0080] It is also possible that the sliding surface 14 ends below the upper edge or radial outer edge of the projection 13.

[0081] The embodiment according to Figures 2, 3, and 4 is constructed similarly to the embodiment according to Figures 1 and 2. The main difference is that the sliding surfaces 14 in the embodiment according to Figures 2, 3, and 4 are curved, as is the case in Figure 13 with a different curvature. With regard to the engagement element 12, the other features of the above embodiment according to Figures 1 and 2 are transferable.

[0082] Specifically, the entire engagement element 12 is curved in the axial direction of the implant 11. The proximal front side of the engagement element 12 is convexly curved.

[0083] During production, the engagement element is cut, in particular laser-cut, from the side of a tube or hollow cylinder. The convex curvature results from the outer diameter of the tube. The opposite concave curvature of the engagement element on its distal side results from the inner diameter of the tube. The engagement means or projections are also cut laterally from the tube or hollow cylinder.

[0084] The convex curvature is clearly visible in Fig. 13.

[0085] The manufacture and orientation of the projections 13 or wings result in different curvatures.

[0086] The upper projection 13 in Fig. 13 is the most curved. It has a sharp edge on the distal side, which is ground down to form a counter-bevel 21. The other two, less curved projections 13 do not require a counter-bevel. Alternatively, the engagement element 12 can be formed as a convex disc or a hollow spherical segment that is uniformly curved around the center with a radius r. This results in a uniform outer curvature of the engagement element 12, which forms the curved sliding surface 14. The projections 13 are provided, as in the previous embodiments, on the outer diameter of the engagement element 12 and form the engagement means required for anchoring the implant 11. The outer curvature of the engagement element 12 continues in the region of the projections

[0087] 13 evenly, so that the desired curved sliding surfaces are also

[0088] 14 are trained.

[0089] The embodiment according to Fig. 3 shows how the engagement element 12 can be used for different connection types. In the example according to Fig. 3, the engagement element 12 is combined with a stop 17, which is arranged proximally of the engagement element 12 and serves to push the implant 11 distally within the catheter or to hold the implant 11 stationary when the catheter is withdrawn. A free space 18 is formed between the engagement element 12 and the stop 17, in which, for example, X-ray markers are arranged. These markers are provided at the proximal end of the implant 11 and are used as locking means in addition to positioning the implant.

[0090] Other connection types are possible. For example, the curved engagement element 12 according to Figs. 2, 3, 4, and 13 can be used as a double connection for a mesh or, more generally, a lattice structure of the implant 11, as in the example shown in Fig. 1.

[0091] Figures 5, 6, and 7 show various embodiments of an engagement element 12, in particular a sleeve-shaped engagement element 12 with a plurality of projections 13, each forming an engagement section 19, 19a, 19b, 19c. The engagement sections 19, 19a, 19b, 19c form connected rings arranged axially one behind the other along the longitudinal axis of the engagement element 12. The projections 13 of the respective engagement sections 19, 19a, 19b, 19c are arranged offset in the circumferential direction. This achieves particularly secure locking and uniform force transmission to the implant 11.

[0092] In the example according to Fig. 5, three engagement sections 19a, 19b, 19c are provided, which are arranged one behind the other in the longitudinal direction of the implant 11. The projections 13 of each engagement section 19a, 19b, 19c are offset from the projections 13 of the other two engagement sections 19a, 19b, 19c in the circumferential direction of the engagement element 12.

[0093] The embodiments according to Figures 5, 6, and 7 have in common that the projections 13 of the first engagement portion 19a have sliding surfaces 14 in the proximal direction, and the projections 13 of the second engagement portion 19b have sliding surfaces 14 in the distal direction. The first and second engagement portions 19a, 19b are arranged at the proximal and distal ends of the engagement element 12, respectively.

[0094] The respective sliding surfaces 14 on the projections 13 of the first and second engagement sections 19a, 19b thus form the axially outer contact surfaces that come into contact with the implant, specifically with the lattice structure of the implant. This allows the implant to move in both axial directions, i.e., in the proximal and distal directions, on the sliding surfaces 14. In other words, the wire 10, and with it the engagement element 12, can be moved in both the proximal and distal directions to press the implant radially outward on the sliding surfaces 14.

[0095] In the example according to Fig. 5, the inward-facing end faces of the projections 13, which are opposite the sliding surfaces 14, are arranged perpendicular to the wire 10. This is unproblematic because the respective opposite sliding surfaces 14 are inclined and thus enable the implant to be lifted off the engagement element 12.

[0096] In the example according to Fig. 5, a third engagement section 19c is provided, which is arranged between the first and second engagement sections 19a, 19b. The projections 13 of the third engagement section 19c have vertical end faces, i.e., no sliding surfaces 14. Furthermore, the projections 13 of the third engagement section 19c are shorter in the axial direction than the projections 13 of the first and second engagement sections 19a, 19b, specifically approximately shorter by the longitudinal component of the sliding surface 14. This provides the release function (with an approximately constant lattice structure of the implant 11), as explained above for the inner end faces.

[0097] In the example according to Fig. 5, the sliding surfaces 14 are designed as straight chamfers 15.

[0098] A similar embodiment is shown in Fig. 7. There, too, three engagement sections 19a, 19b, 19c are provided, in which the projections 13 are offset from one another. However, only the projections of the middle, third engagement section 19c are offset from the other two engagement sections 19a, 19b, which are again aligned with one another. Another difference is that the sliding surfaces 14 are formed as a combination of straight chamfers 15 and curved sections. The projections 13 are in the shape of hills with a straight plateau.

[0099] The embodiment according to Fig. 6 has two engagement sections 19a, 19b, i.e., exactly two engagement sections 19a, 19b. In contrast to the example according to Fig. 5, each projection 13 has a sliding surface 14 on both end faces, i.e., both proximal and distal. The sliding surfaces 14 are designed in the form of chamfers 15. Here, too, the advantage is that the engagement element 12 can be moved in both axial directions to release the implant.

[0100] The engagement elements 12 of Figures 5, 6 and 7 can be manufactured, for example, by mechanical processing such as milling, laser material processing or by additive manufacturing processes such as 3D printing.

[0101] Another embodiment is shown in Figures 8 and 9, which can be manufactured particularly flexibly.

[0102] In this embodiment, the sliding surfaces 14 are formed by a shrink tube 16 that encloses the engagement element 12 in the circumferential and axial directions. The engagement element 12 can comprise a known ring or sleeve with engagement means that have vertical end faces. The engagement means can be designed as in the prior art. The engagement means act as a core for the shrink tube 16 and, together with it, form the projections 13. The engagement means can also be referred to as an engagement profile core.

[0103] The outer contour of the engagement element 12 required for the desired effect is determined by the shape of the shrink tube 16. The engagement means or the engagement profile under the shrink tube 16 stabilizes it and is responsible for the rough contour of the engagement element 12. The shape of the outer contour in the axial direction of the implant 11 can be adjusted by the preconditioned shrink tube 16 and the heat treatment so that the sliding surfaces 14 have the desired inclination or curvature. This is shown in Figs. 8 and 9.

[0104] It is understood that the sliding surfaces 14 in the shrink tube 16 are geometrically less precisely definable than, for example, in the case of a bevel according to Fig. 1. In any case, in contrast to the vertical end face, a smooth transition is formed from the wire 10 to the upper side of the projection 13 through the shrink tube 16, which serves as the sliding surface 14. The sliding surface 14 of the shrink tube 16 can also be regarded as inclined and / or curved, in the sense that no geometrically exact inclination or curvature is required, but rather a free-form surface deviating from the vertical end face of the projection, which functionally serves as a run-on bevel for the lattice structure of the implant 11.

[0105] Preferably, the shrink tube 16 is adapted to the lateral contour of the engagement means or core, ie it lies somewhat more closely there than on the end surfaces where the sliding surfaces 14 are formed.

[0106] As shown in Fig. 9, the shrink tubing 16 can enclose multiple engagement elements 12 or one engagement element 12 and a stop 17 (Fig. 3). In the latter example, a free space 18 is provided for the reception of X-ray markers. Other connection types are also possible here. Instead of the shrink tubing, a flexible tube, e.g., a polymer tube, can be used.

[0107] The above-described embodiments according to Figures 1 to 9 have in common that the release direction runs in the longitudinal direction of the implant 11. The examples according to Figures 10 and 11, in contrast, show another embodiment of the invention in which the release direction, at least the initial release direction, runs in the circumferential direction of the implant 11. In the example according to Figures 10 and 11, the implant 11 is shown in cross-section (highly schematic).

[0108] The sliding surface 14 is inclined and / or curved in the circumferential direction of the implant 11. In the case of multiple projections, as shown in Fig. 10, the sliding surface 14 of the respective projections 13 is inclined and / or curved in the circumferential direction of the implant 11. The respective sliding surfaces 14 are oriented in the same circumferential direction, i.e., clockwise or counterclockwise. In the example according to Figs. 10 and 11, the sliding surfaces 14 are oriented counterclockwise.

[0109] The sliding surfaces 14 are formed as chamfers 15. Other shapes of the sliding surfaces 14, for example, curved sliding surfaces 14 or spiral-shaped sliding surfaces 14, are possible.

[0110] The engagement element 12 is connected to the wire 10 in a rotationally fixed manner. To actuate the engagement element 12, a torque is introduced via the wire 10 into the engagement element 12, which rotates with the wire 10, as shown in Fig. 11. The rotation of the engagement element 12 causes the sliding surfaces 14 to move relative to the implant 11, specifically to the lattice structure. The implant 11 is thereby pushed radially outward and lifted, with the lattice structure causing the implant to be lifted as a whole.

[0111] Once the implant 11 is sufficiently raised, the wire 10, together with the engagement element 12, is pulled out of the implant 11 in the proximal direction. The arrangement according to the examples explained above is used with a catheter as follows.

[0112] The implant 11 is released through an axial relative movement between the catheter and the implant. There are various ways to do this. For example, the catheter can be retracted proximally at the treatment site until the implant 11 emerges from the catheter. The wire 10 holds the implant 11 stationary at the desired location. Alternatively, the catheter can be stationary, and the implant is gently pushed distally out of the catheter using the wire.

[0113] The implant 11 thereby unfolds or expands successively in the proximal direction with increasing release. When the implant 11 expands in the region of the engagement element 12, the implant 11 is released from the wire 12 due to the radial expansion and is separated from the engagement element 12. If the separation is not complete and the implant 11 and the engagement element 12 overlap, the implant 11, in the examples according to Figures 1 to 9, is pressed radially outwards by the sliding surfaces 14 by a movement of the wire 10 in the proximal direction. The wire 10 is safely released. In the examples according to Figures 10 and 11, the wire 10 and the engagement element 12 are rotated so that the implant is pressed outwards by the sliding surfaces 14. The wire 10 can then be withdrawn here too.

[0114] The implant is completely released and positioned at the desired location in the vessel to be treated.

[0115] List of reference symbols

[0116] 10 Wire (transport wire)

[0117] 11 Implant

[0118] 12 engagement element (sleeve)

[0119] 13 lead

[0120] 14 Sliding surface

[0121] 14a first sliding surface section

[0122] 14b second sliding surface section

[0123] 15 Chamfer 16 Shrink tubing

[0124] 17 stop

[0125] 18 open space

[0126] 19 engagement section 19a first engagement section

[0127] 19b second intervention section

[0128] 19c third intervention section

[0129] 20 inner ring

[0130] 21 Counter bevel

Claims

CLAIMS 1. Arrangement for delivering a medical implant into a hollow body organ, comprising a wire (10) and a compressible and expandable medical implant (11) which is tubular in shape, - wherein the implant (11) in the compressed state is detachably connected to the wire (10) by at least one engagement element (12) for transmitting force in the axial direction, wherein the engagement element (12) has at least one projection (13) which extends radially outwards and engages the implant (11), and - wherein the implant (11) in the at least partially expanded state can be released by a relative movement between the engagement element (12) and the implant (11) in a release direction, characterized in that the engagement element (12) has at least one sliding surface (14) which is inclined and / or curved in the release direction and cooperates with the projection (13) to release the implant (11).

2. Arrangement according to claim 1, characterized in that the sliding surface (14) is inclined and / or curved in the longitudinal direction of the implant (11), in particular in the distal longitudinal direction.

3. Arrangement according to claim 1 or 2, characterized in that the inclined sliding surface (14) comprises a chamfer (15) which is formed at least in the region of the outer edge () of the projection (13).

4. Arrangement according to claim 3, characterized in that the chamfer (15) starts at the base of the projection (13).

5. Arrangement according to one of the preceding claims, characterized in that the engagement element (12) has at least at one axial end a conical profile with the correspondingly inclined projection (13) which forms the inclined sliding surface (14).

6. Arrangement according to claim 1 or 2, characterized in that the engagement element (12) is curved in the axial direction of the implant (11), wherein the projection (13) is formed on the outer curvature of the engagement element (12) with a corresponding curvature and forms the curved sliding surface (14).

7. Arrangement according to claim 1 or 2, characterized in that the inclined and / or curved sliding surface (14) comprises a tube, in particular a shrink tube (16), which envelops the engagement element.

8. Arrangement according to one of the preceding claims, characterized in that the sliding surface (14) is inclined and / or curved in the circumferential direction of the implant (11).

9. Arrangement according to one of the preceding claims, characterized in that several, in particular two, engagement elements (12) are arranged, each with at least one sliding surface (14), axially spaced from one another in the longitudinal direction of the wire (10), the sliding surfaces (14) being oriented in the same direction.

10. Arrangement according to one of claims 1 to 9, characterized in that the engagement element (12) is assigned a proximal stop (17) which is arranged at an axial distance from the engagement element (12) in the longitudinal direction of the wire (10) to form a free space (18).

11. Arrangement according to one of the preceding claims, characterized in that the engagement element (12) has a plurality of projections (13) which are arranged distributed over the circumference of the engagement element (12), each having at least one sliding surface (14) and forming an engagement section (19).

12. Arrangement according to claim 11, characterized in that the engagement element (12) has a plurality of engagement sections (19a, 19b, 19c) in the longitudinal direction of the wire (10), wherein the projections (13) of the various engagement sections (19a, 19b, 19c) are arranged offset in the circumferential direction.

13. Arrangement according to claim 11 or 12, characterized in that the projections (13) of a first engagement section (19a) have sliding surfaces (14) at least in the proximal direction and the projections (13) of a second engagement section (19b) have sliding surfaces (14) at least in the distal direction.

14. Wire for delivering a tubular medical implant (11) into a hollow body organ, with at least one engagement element (12), wherein the implant (11) is compressible and expandable, - wherein the implant (11) in the compressed state is connectable to the wire (10) by the engagement element (12) for transmitting force in the axial direction, wherein the engagement element (12) has at least one projection (13) which extends radially outwards and engages the implant (11) in use, and - wherein the implant (11) in the at least partially expanded state can be released by a relative movement between the engagement element (12) and the implant (11) in a release direction, characterized in that the projection (13) has at least one sliding surface (14) for releasing the implant (11), which is inclined and / or curved in the release direction.

15. A catheter having an arrangement according to claim 1.

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