Medical implant and set

Abstract

The invention relates to a medical implant for treating a local lesion (100) in a vessel, in particular for aneurysm treatment, with a tubular support body (10) that is compressible and expandable, wherein the support body (10) in a resting state has a proximal section (11) and a distal section (12) which are connected to each other by a central segment (13), wherein the length of the central segment (13) is variable in the axial direction, wherein a cover (14) spans the central segment (13) and the length of the central segment (13) is variable upon release from a delivery device (50) such that the lesion (100) can be at least partially covered by the cover (14).

Description

The invention relates to a medical implant for treating a local lesion in a vessel, in particular for aneurysm treatment, having a tubular support body which is compressible and expandable, wherein the support body in a rest state has a proximal section and a distal section which are connected to one another by a central segment, wherein the length of the central segment can be changed in the axial direction. An implant according to the preamble of claim 1 is known, for example, from WO 002008070423 A1.Medical implants are used for the treatment of vascular lesions, such as aneurysms, which reduce the blood flow into the aneurysm so that the blood located in the aneurysm can coagulate. The position of the implant can limit the blood flow in the vessel, in particular in branch vessels. It is therefore expedient to adapt the implant geometry to the anatomy. From WO 002008070423 A1 mentioned at the beginning, for example, a medical implant with variable geometry is known. However, it is disadvantageous that the treatment of a lesion, such as in particular an aneurysm, is only possible to a limited extent.The object of the invention is therefore to specify a medical implant which, on the one hand, enables the treatment of a lesion, in particular an aneurysm, and, on the other hand, ensures the blood flow in the vessel, in particular in branching vessel arms. Furthermore, the object of the invention is to specify a set with such a medical implant.According to the invention, this object is achieved by the subject matter of claim 1. With regard to the kit, this object is achieved by the subject matter of claim 13.Specifically, this object is achieved by a medical implant for the treatment of a local lesion in a vessel, in particular for aneurysm treatment, having a tubular supporting body which is compressible and expandable. In this case, in a rest state, the supporting body has a proximal section and a distal section which are connected to one another by a central segment, wherein the length of the central segment can be changed in the axial direction. A cover spans the central segment. The length of the central segment can be changed when it is discharged from a delivery device in such a way that the lesion can be covered at least partially by the cover.The invention has the advantage that the implant on the one hand enables good treatment of a lesion and on the other hand ensures the blood flow in the vessel, in particular in branching vessel arms.In order to achieve a good treatment of the lesion, the length of the medically effective region of the implant, i.e. the central segment with the cover, can be adapted to the anatomy of the patient. The cover is adapted to the central segment in such a way that the cover can follow the change in length of the central segment.For this purpose, the cover can be designed differently. For example, the cover can span over the central segment in such a way that it rests loosely on the central segment in the shortened state of the central segment. In other words, the cover can be arranged on the central segment in such a way that the cover is compressed or, in particular, forms a corrugated surface if the length of the central segment is reduced. Furthermore, the cover can be designed in such a way that the cover contracts upon shortening of the central segment. Alternatively, it is possible for the cover to span the central segment such that the cover is stretched as the length of the central segment is increased. The aim is thereby followed with the change in length of the cover that the cover covers the lesion in such a way that the blood flow into the lesion is reduced, so that the blood located in the lesion can coagulate.It is furthermore advantageous that the lesion alone is covered by changing the length of the central segment or of the cover. Diverging vessels located near the lesion may be kept free. This is achieved in that the change in length of the central segment or of the cover enables an adaptation of the region of the implant free of a corner to the vascular branches. Consequently, an unimpeded blood flow and thus the supply of subsequent tissue areas is ensured.Specifically, the length of the central segment is variable upon discharge from a feeder. This is to be understood in such a way that the length of the central segment can be adjusted by exerting tension or pressure on the delivery device, for example on a catheter. For this purpose, for example, the distal section of the implant is initially released from the delivery device and anchored distally in relation to the lesion in the vessel. The length adjustment of the central segment or of the cover can then take place. For this purpose, tension or pressure is exerted on the central segment with the aid of the feed device in order to shorten or lengthen the latter. The proximal portion of the implant can then be released from the delivery device and anchored proximally with respect to the lesion in the vessel. As a result, the length of the central segment or of the cover can be fixed.Furthermore, the change in length of the central segment or of the cover is advantageously substantially reversible during the release from a supply device. This means that an operator can change the length of the central segment until the implant is anchored in the vessel by the proximal and distal sections or is completely released from the delivery device. It is particularly advantageous here that the length of the central segment or of the cover can be changed continuously or continuously.Preferred embodiments of the invention are set forth in the dependent claims.Preferably, the covering comprises at least one electrospun portion, the electrospun portion being porous such that blood flow in the implanted state is partially deflected from the lesion by the covering. In particular, the cover can be designed as an electrospun cover. In other words, the cover can be formed completely as an electrospun cover or can have only one or more electrospun sections. In other words, the cover advantageously comprises at least one section of an electrospun fleece. Particularly preferably, the cover is formed by a plastic material, in particular by a polymer, and preferably by thermoplastic polyurethane. Such materials can be produced particularly well in fine filaments by an electro-spinning process. Consequently, the cover can be formed from irregularly netlike arranged filaments. The plastic material thus makes it possible to produce a particularly fine or thin cover.The thread diameter is preferably less than 2500 nm, in particular less than 800 nm. The covering can have a total layer thickness of less than 150 μm. Further, the cover may have at least 10 pores with a size of at least 15 μm 2 on an area of 100,000 μm 2.Further, the at least one electrospun portion may be formed slightly porous to reduce blood flow into the lesion through the covering. In other words, the covering of an aneurysm can be made possible, wherein at the same time a certain permeability for blood can be ensured. This permeability is advantageous for feeding the cells of the aneurysm wall with nutrients. As a result, degeneration of the cells and a possibly resulting rupture of the aneurysm can be avoided.In general, for an electrospun nonwoven, the pores are irregularly shaped. The production method does not in any case allow a pattern-like arrangement or design of pores to be produced. However, the pore sizes can be set on the basis of the process parameters at least to such an extent that it is ensured that at least some of the pores have a certain minimum size. Thus, the minimum size of the pores can be adjusted, for example, by the process duration during electro-spinning.Furthermore, the cover is advantageously firmly connected to the proximal and / or distal section of the support body. In other words, the cover is fixed to the proximal and / or distal section and only rests on the central segment. As a result, a relative mobility between the cover and the central segment can be achieved. The process of electro-spinning can take place directly on the support body or the proximal and distal section, so that a connection to the support body is simultaneously produced during the formation of the cover. The cover can alternatively be connected to the supporting body in a materially integral manner. For example, the cover can be connected to the supporting body by an adhesive connection. The adhesive connection can be produced by an adhesion promoter. The adhesion promoter can comprise polyurethane or consist thereof, for example.In a preferred embodiment, the cover is fixedly connected to the central segment at least partially, in particular at local locations. This is to be understood in such a way that the cover can optionally be fastened at individual points on the central segment. This ensures secure retention of the cover on the central segment, wherein a certain relative mobility between the central segment and the cover can be obtained.Furthermore, the central segment preferably has a grid structure made of webs which are connected to one another and form closed, in particular diamond-shaped, cells, wherein the cells are firmly connected to one another in the circumferential direction of the grid structure. In other words, the basic shape of the cells is substantially diamond-shaped. The diamond-shaped cells can be bounded by a plurality of webs, in particular four webs. The webs can be connected to one another via different web connectors, in particular X-shaped web connectors. Furthermore, the cells can be immovable with respect to one another in the circumferential direction of the central segment. It is advantageous that a grid structure of webs and consequently the central segment can be produced simply by laser cutting from a tube.Preferably, in each case two cells are connected to one another in the axial direction of the grid structure by a connecting element, in particular a connecting sleeve, in such a way that the distance between the two cells can be changed in the axial direction of the grid structure in order to change the length of the central segment. In other words, the change in distance between the cells advantageously brings about the change in length of the central segment. In this case, the diamond-shaped cells can each have, at their proximal and distal ends, an extension in the form of an, in particular straight, connecting web which extends in the axial direction of the grid structure. The connecting web of a cell can be connected via a connecting element to the connecting web of an adjacent cell. An undercut can thereby form between two connecting webs of two adjacent cells. In other words, the connecting webs of two adjacent cells can move past one another. A connecting element can in this case enclose two connecting webs over the full circumference. Furthermore, the connecting webs can have a shoulder or a stop for the connecting element at their ends in order to ensure a secure cohesion of the cells in the axial direction. Here, it is advantageous that the axial displaceability of the cells and consequently the change in length of the central segment are made possible by a simple structural design of the lattice structure.The connecting element is furthermore preferably formed from an X-ray-visible material, in particular from platinum or a platinum alloy. This ensures good X-ray visibility of the implant. A correct positioning of the central segment in the region of an aneurysm can be facilitated.In a particularly preferred embodiment, two webs of a cell which are connected to one another in the circumferential direction of the central segment form a first and a second web pair, wherein the first web pair has a lower strength than the second web pair, such that the first web pair is deformable in such a way that the central segment is compressible in the axial direction. In other words, the first pair of webs together with the second pair of webs can form the boundary of the cell. It is not excluded here that the cell is bounded by further webs. Furthermore, the first pair of webs can have a different structural design than the second pair of webs. This can make it possible for the first pair of webs to be deformable in such a way that the lattice structure is compressible in the axial direction. Specifically, the first pair of webs can be designed to be plastically deformable in order to change the length of the central segment in the axial direction.Furthermore, the webs of the first web pair advantageously have a different, in particular smaller, web width than the webs of the second web pair. This can ensure that only the first pair of webs undergoes deformation and the second pair of webs remains undeformed.Preferably, the webs of the first web pair have a curvature, in particular an S-shaped curvature. Here, it is advantageous that bending points of the web can be defined by the curvature. It is thus possible to define at which locations the webs of the first web pair are deformed when the central segment is compressed.Alternatively, the webs of the first pair of webs can have a smaller web width in the region of the ends in a region which extends between the ends of the webs. In this way, it is possible to generate defined curvature points of the webs.In a further preferred embodiment, the central segment has a grid mesh of wires which are each wound about a longitudinal axis of the central segment and cross over and under, wherein the wires are at least partially displaceable relative to one another in the axial direction of the grid mesh in order to change the length of the central segment. It is advantageous here that the mesh braid can be produced simply by braiding wires, for example on a braiding mandrel.Furthermore, the wires are preferably wound in such a way, in particular in a zig-zag pattern, that the wires are displaceable relative to one another until the wires interlock. This is to be understood in such a way that the wires can be displaced in the axial direction from a position in which the wires merely overlap into a further position in which the wires interlock. The entanglement of the wires thus forms the maximum deflection or length of the central segment. In this way, the length of the central segment can be changed particularly easily.Preferably, the wires are formed from an radiopaque core material encased in a shape memory material. The shape memory material can be, for example, a nickel-titanium alloy, such as nitinol, or another biocompatible alloy. Such wires are, for example, wires of this type. Known as DFT wires. In other words, the wires are a composite material which has a radiopaque moiety. The radiopaque portion may be formed of platinum or a platinum alloy. As a result, the implant is readily visible under X-ray control.According to an independent claim, the invention relates to a set comprising a medical implant according to one of the preceding claims and a delivery device, in particular a catheter system, for delivering and releasing the implant in the region of a local lesion in a vessel, in particular for the treatment of an aneurysm.The invention is explained in more detail with reference to exemplary embodiments in conjunction with the schematic drawings.These show FIG. 1 shows a set according to the invention comprising a medical implant and a delivery device; FIG. 2 shows a set according to the invention according to FIG. 1, wherein the length of the central segment of the implant is changed; FIG. 3 shows a medical implant according to the invention in the implanted state in the vessel; FIG. 4 shows an exemplary embodiment of a medical implant according to the invention with a braid structure of wires; FIG. 5 shows a further exemplary embodiment of a medical implant according to the invention having a lattice structure of webs and a connecting element; and FIG. 6 shows a further exemplary embodiment of a medical implant according to the invention with a lattice structure of webs and a deformable web pair.The same reference numbers are used below for identical or identically functioning parts.FIGS. 1 to 3 show an exemplary embodiment of a medical implant according to the invention for the treatment of a local lesion 100. This is the use of the medical implant for the treatment of aneurysms 100. Other applications are conceivable. Generally, the implant is suitable for treating vascular lesions such as stenosis.It is furthermore shown in FIGS. 1 to 3 that the medical implant has a tubular support body 10 which is compressible and expandable. It can be seen that the supporting body 10 is substantially cylindrical and is suitable for insertion into a vessel. For this purpose, the supporting body 10 is compressible and expandable.It can also be seen from FIGS. 1 to 3 that the support body 10 has a proximal and a distal section 11, 12. The two sections 11, 12 serve to anchor the support body 10 in the vessel. It can be seen in FIG. 3 that the proximal and distal sections 11, 12 are positioned in the vessel in such a way that the treatment of an aneurysm 100 or the covering of an aneurysm 100 is made possible. In other words, in the implanted state, the proximal and distal sections 11, 12 are respectively arranged proximally and distally with respect to the aneurysm 100.As shown in Figs. 1-3, the proximal and distal sections 11, 12 are interconnected by a central segment 13. In this case, the central segment 13 serves to cover the lesion 100 or the aneurysm 100. The proximal and distal sections 11, 12 anchor or position the implant in the vessel in such a way that the aneurysm 100 is covered by the central segment 13.FIG. 2 also illustrates that the length of the central segment 13 can be changed in the axial direction. This means that the length of the central segment 13 can be increased or reduced. In other words, the central segment 13 is compressible or extensible in the axial direction. It can be seen here that by changing the length of the central segment 13, the length of the implant itself or of the support body 10 can be changed, wherein the length of the proximal and distal sections 11, 12 is constant.It can also be seen from FIGS. 1 to 3 that a cover 14 spans the central segment 13. It can be seen that the cover 14 extends from the proximal to the distal end of the central segment 13. Alternatively, it is conceivable that the cover 14 extends as far as the proximal and / or distal section 11, 12 of the support body 10. In Figures 1 to 3, the proximal and distal portions 11, 12 are largely free of cover. Furthermore, the cover can span the entire implant or the supporting body.In FIG. 2, it is shown that the length of the central segment 13 can be changed when it is discharged from a delivery device 50 or from a catheter 50. Specifically, the central segment 13 is compressible by applying pressure to the catheter 50. By pulling on the catheter 50, the central segment 13 is stretchable. In this case, an operator adjusts the length of the central segment 13 when it is discharged from the catheter 50 by alternately pulling and pressing the catheter 50 such that the central segment 13 partially or completely covers a lesion 100. This allows the length of the middle segment 13 to be adjusted correctly during surgery to ensure efficient treatment of the lesion 100.It can also be seen in FIG. 2 that a change in the length of the cover 14 is effected by the change in the length of the central segment 13. In other words, the change in length of the central segment 13 is accompanied by a change in length of the cover 14. As a result, the length of the cover 14 is adapted to the lesion 100 to be treated or to the aneurysm 100 in such a way that the blood flow is deflected from the lesion 100. It can be seen that the cover 14 is formed or arranged so as to be relatively movable with respect to the central segment 13.As shown in FIG. 3, the length of the central segment 13 or of the cover 14 in the implanted state is fixed by anchoring the proximal and distal sections 11, 12 in the vessel. This is to be understood in such a way that the proximal and distal sections 11, 12 have a fixed length and delimit the length-adjustable middle segment 13. Thus, a stationary positioning of the proximal and distal sections 11, 12 in the vessel results in the length of the central segment 13 being maintained in the implanted state.Furthermore, FIGS. 1 to 3 show that the cover 14 is designed in the form of an electrospun cover 14. Here, the cover 14 is formed of a plastic material such as polyurethane. Another configuration of the cover 14 is conceivable. For example, the cover 14 may be formed of textile materials.The electrospun cover 14 shown in FIGS. 1 to 3 is also porous. Here, the cover 14 has at least 10 pores having a size of at least 15 μm 2 on an area of 100,000 μm 2. This combination of a certain minimum number of pores and a minimum size of these pores has been shown in practice to be particularly favourable for an adequate blood permeability of the cover 14 with simultaneously good covering action. Alternatively, it is conceivable that the electrospun cover 14 has a different number of pores or pores of a different size. For example, the cover 14 can have a porosity of at most 70%, in particular at most 50%. It is likewise possible for the covering 14 to have a porosity of at least 5%, in particular at least 10%, in particular at least 20%, in particular at least 30%, in particular at least 40%, in particular at least 45%.It can also be seen in FIGS. 1 to 3 that the cover 14 is firmly connected to the proximal and distal sections 11, 12 of the supporting body 10. This is to be understood in such a way that the cover 10 is fastened to the proximal and distal sections 11, 12 and only rests on the central segment 13. The fixed connection of the cover 14 to the proximal and distal sections 11, 12 results from the process of electro-spinning being carried out directly on the two sections 11, 12. Alternatively, the cover 14 can be connected to the proximal and distal sections 11, 12 by adhesion promoters in a materially integral manner.Furthermore, it can be seen in FIGS. 1 to 3 that the connection of the cover 14 to the proximal and distal sections 11, 12 results in a relative mobility of the cover 14 with respect to the central segment 13. Specifically, the cover 14 is stretched or compressed over the center segment 13 when the length of the center segment 13 is changed. The porosity of the cover 14 increases when it is stretched. Conversely, the porosity decreases when the cover 14 is compressed. The cover 14 is thus compressed or stretched upon itself when the central segment 13 undergoes a change in length. In other words, the threads of the cover contract into themselves or stretch. Alternatively or additionally, it is conceivable that the cover 14 strikes waves when the length of the central segment 13 is reduced.In the exemplary embodiment according to FIGS. 1 to 3, the cover 14 is furthermore fixedly connected to the central segment 13 at local locations. In this case, the cover 14 is fixed or fastened at a plurality of points on the central segment 13. Alternatively, the cover 14 lies only on the middle segment 13 or spans the middle segment 13.In FIGS. 5 a, 5 band 6, it is shown that the central segment 13 has a lattice structure 15 made of webs 16 a- 16 dwhich are connected to one another and form closed cells 17. Specifically, the cells 17 are diamond-shaped. It can be seen that the cells 17 are each bounded by four webs 16 a- 16 d. In this case, two cells 17 adjacent in the axial direction are shown in FIGS. 5 a, 5 band 6.Furthermore, the cells 17 are firmly connected to one another in the circumferential direction of the grid structure 15 (not shown). This means that a change in length of the grating structure 15 takes place only in the axial direction.In the exemplary embodiment according to FIGS. 5 aand 5 b, two cells 17 are connected to one another in each case in the axial direction of the grid structure 15 by a connecting element 18. Specifically, all cells 17, with the exception of the boundary cells of the central segment 13, each have an additional connecting web at their proximal and distal ends. The connecting webs of two adjacent cells 17 are connected via the connecting element 18. The connecting element 18 is designed in the form of a connecting sleeve 18. A connecting sleeve 18 encloses two connecting webs over the full circumference. Furthermore, the connecting sleeve 18 is arranged displaceably on the connecting webs. Furthermore, the connecting sleeve 18 is arranged in each case centrally between two cells 17. Other configurations and arrangements of the connecting element 18 are conceivable.Furthermore, it can be seen from FIGS. 5 aand 5 b that the cells 17 adjacent in the axial direction are connected to one another by the connecting elements 18 in such a way that the distance between the two cells 17 can be changed in the axial direction of the grid structure 15. This is to be understood in such a way that the cells 17 can move towards one another or away from one another in the axial direction. By this change in distance between the cells 17 of the grating structure 15, the length of the central segment 13 can be changed.FIG. 5 ashows the smallest possible distance between two cells 17 adjacent in the axial direction. It can be seen that the distance between the cells 17 can be reduced until the connecting web of one cell 17 meets the webs 16 a- 16 dof the other, diamond-shaped basic cell. If the distance between all cells 17 adjacent in the axial direction is set as small as possible, the middle segment 13 has its smallest possible length.FIG. 5a shows the largest possible distance between two cells 17 adjacent in the axial direction. It can be seen that the distance between the cells 17 can be increased until the connecting element 18 or the connecting sleeve 18 meets the stops of the connecting webs. If the distance between all the cells 17 of the middle segment 13 adjacent in the axial direction is set as large as possible, the middle segment 13 has its greatest possible length.Furthermore, it can be seen in FIGS. 5 aand 5 b that the distance between the cells 17 can be continuously changed in the axial direction. Consequently, the length of the center segment 13 is continuously variable. This means that any distance between the cells 17 that is between the distance shown in Figs. 5a and 5b is adjustable.Furthermore, the connecting element 18 shown in FIGS. 5 aand 5 bis formed from an X-ray-visible material. Specifically, the connecting element 18 or the connecting sleeve 18 is formed from platinum or a platinum alloy. Other materials are conceivable.In the exemplary embodiment according to FIG. 6, two webs 16 a- 16 dof a cell 17, which are connected to one another in the circumferential direction of the central segment, form a first and a second web pair 16 a- 16 d. In this case, the first pair of webs 16 a, 16 bhas a lower strength than the second pair of webs 16 c, 16 d, such that the first pair of webs 16 a, 16 bis deformable in such a way that the central segment 13 is compressible in the axial direction. The first pair of webs 16 a, 16 bis illustrated at the top in FIG. 6 in the idle state, i.e. in the undeformed state. FIG. 6 shows the first pair of webs 16 a, 16 bin the deformed state. It can be seen here that the first pair of webs 16 a, 16 bis deformed in such a way that the shape of the cell 17 deviates from the diamond-shaped basic structure of the cell 17. In other words, the cell 17 is compressed. This compression of the cell 17 leads to a change in the length of the central segment 13.It can be seen in FIG. 6 that the webs of the first web pair 16 a, 16 bhave a smaller web width than the webs of the second web pair 16 c, 16 d. This ensures that only the first pair of webs 16 a, 16 bis deformed when pressure is exerted on the cells 17 via a delivery device 50 such as a catheter 50.FIG. 6 also illustrates that the webs of the first pair of webs 16 a, 16 bhave an S-shaped curvature. This curvature ensures that the webs of the first pair of webs 16 a, 16 bdeform as shown in FIG. 6 when the central segment 13 is compressed.In the exemplary embodiment according to FIG. 4, the central segment 13 has a grid mesh 19 of wires 20 which are each wound about a longitudinal axis of the central segment 13 and cross over and under. It can be seen that the wires 20 are at least partially displaceable relative to one another in the axial direction of the grid mesh 19. By displacing the wires 20 with the aid of a catheter 50, the length of the central segment 13 is changed.Furthermore, it can be seen from FIG. 4 that the wires 20 are wound in a zig-zag pattern, so that the wires 20 are displaceable relative to one another until the wires 20 interlock.On the left in FIG. 4, it can be seen that the wires 20 of the zig-zag pattern are close to one another. This arrangement of wires 20 is achieved by pressing on catheter 50. If the wires 20 are close to one another on the left as in FIG. 4, the central segment 13 is compressed or the central segment 13 has a short length.On the right in FIG. 4, it can be seen that the wires 20 of the zig-zag pattern are arranged at a distance from one another. This arrangement of wires 20 is achieved by pulling on catheter 50. If the wires 20 are arranged or hooked into one another at a right distance from one another as in FIG. 4, the central segment 13 consequently has a greater length. Figure 4 on the right thus illustrates the maximum deflection of the wires 20.Furthermore, the wires 20 shown in FIG. 4 are formed of an X-ray-visible core material sheathed with a shape memory material. Specifically, the wires 20 are formed as DFT wires.Referring now to Figures 1 and 2, there is shown a kit according to the invention comprising a medical implant and a catheter system 50 for delivering and releasing the implant. In this case, the catheter system 50 is used to position the implant in the region of the lesion 100 in such a way that the central segment 13 or the cover 14 of the implant covers the lesion 100 in such a way that the blood flow into the lesion 100 is reduced. For this purpose, the distal section 12 of the implant is first released from the catheter 50 and positioned distally with respect to the lesion 100 or at the distal edge of the aneurysm neck 100 and anchored in the vessel (FIG. 1 ). The length adjustment of the middle segment 13 is then carried out (FIG. 2 ). For this purpose, tension or pressure is exerted on the central segment 13 with the aid of the catheter 50 in order to shorten or lengthen the latter. The change in length can be effected according to different principles. At this point, reference is made to the various embodiments of the implant according to FIGS. 4 to 6. Next, the proximal portion 11 of the implant is released from the catheter 50 and anchored proximally in the vessel with respect to the lesion 100 (Fig. 3). As a result, the length of the central segment 13 is fixed.List of reference characters10 Support body 11 proximal portion 12 distal portion 13 central segment 14 cover 15 mesh structure 16 a- 16 dbridges 16 a, 16 bfirst pair of bars 16 c, 16 dsecond pair of bars 17 cell 18 connector 19 mesh 20 wires 50 delivery device 100 lesionReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedWO 002008070423 A1 [0001, 0002]

Claims

Medical implant for treating a local lesion (100) in a vessel, in particular for aneurysm treatment, having a tubular support body (10) which is compressible and expandable, wherein the support body (10), in a rest state, has a proximal section (11) and a distal section (12) which are connected to one another by a central segment (13), wherein the length of the central segment (13) can be changed in the axial direction, characterized in that a cover (14) spans the central segment (13) and the length of the central segment (13) can be changed on discharge from a supply device (50) in such a way that the lesion (100) can be at least partially covered by the cover (14).Medical implant according to claim 1, characterised in that the cover (14) has at least one electrospun section, in particular is formed in the form of an electrospun cover, wherein the electrospun section is porous such that the blood flow is partially deflected from the lesion by the cover (14) in the implanted state.Medical implant according to claim 1 or 2, characterised in that the cover (14) is firmly connected to the proximal and / or distal section (11, 12) of the support body (10).Medical implant according to one of the preceding claims, characterized in that the cover (14) is fixedly connected at least partially, in particular at local locations, to the central segment (13).Medical implant according to one of the preceding claims, characterized in that the central segment (13) has a lattice structure (15) made of webs (16a - 16d), which are connected to one another and form closed, in particular diamond-shaped, cells (17), wherein the cells (17) are firmly connected to one another in the circumferential direction of the lattice structure (15).Medical implant according to claim 5, characterised in that in each case two cells (17) are connected to one another in the axial direction of the lattice structure (15) by a connecting element (18), in particular a connecting sleeve, in such a way that the distance between the two cells (17) can be changed in the axial direction of the lattice structure (15) in order to change the length of the central segment (13).Medical implant according to claim 6, characterised in that the connecting element (18) is formed from an X-ray-visible material, in particular from platinum or a platinum alloy.Medical implant according to claim 5, characterised in that two webs (16a - 16d) of a cell (17) which are connected to one another in the circumferential direction of the central segment (13) form a first web pair (16a, 16b) and a second web pair (16c, 16d), wherein the first web pair (16a, 16b) has a lower strength than the second web pair (16c, 16d), such that the first web pair (16a, 16b) is deformable in such a way that the central segment (13) is compressible in the axial direction.Medical implant according to claim 8, characterised in that the webs of the first pair of webs (16a, 16b) have a different, in particular smaller, web width than the webs of the second pair of webs (16c, 16d).Medical implant according to claim 8 or 9, characterised in that the webs of the first web pair (16a, 16b) have a curvature, in particular an S-shaped curvature.Medical implant according to one of claims 1 to 4, characterised in that the central segment (13) has a mesh (19) made of wires (20), which are each wound around a longitudinal axis of the central segment (13) and cross over and under, wherein the wires (20) are at least partially displaceable relative to one another in the axial direction of the mesh (19) in order to change the length of the central segment (13).Medical implant according to claim 11, characterised in that the wires (20) are wound in such a way, in particular in a zig-zag pattern, that the wires (20) are displaceable relative to one another until the wires (20) interlock.Medical implant according to claim 11 or 12, characterized in that the wires (20) are formed from an X-ray-visible core material which is sheathed by a shape memory material.A kit comprising a medical implant according to any one of the preceding claims and a delivery device (50), in particular a catheter system, for delivering and releasing the implant in the region of a local lesion (100) in a vessel, in particular for treating an aneurysm.

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