DE102015122678A1 - Medical implant - Google Patents

Abstract

The invention relates to a medical implant having a tubular lattice structure (10) which can be converted into a radially compressed state and a radially expanded state, wherein the lattice structure (10) has lattice cells (12) delimiting webs (11) and at least one metallic cover element (20). has, which is closed in the circumferential direction of the grid structure (10). The invention is characterized in that the cover element (20) has at least one annular edge portion (21) and an annular or tubular cover portion (23) which adjoins the edge portion (21) and loosely rests on the lattice structure (10) the edge section (21) is connected in one piece, in particular monolithically, to the webs (11) of the lattice structure (10) which are arranged in the region of the edge section (21).

Description

The invention relates to a medical implant according to the preamble of claim 1. Such an implant is for example made EP 1 620 047 B1 known.

In general, stents are known from the prior art, which have a metal cover. Such metal covers are relatively inflexible and therefore complicate the compression of the stent. Especially when inserting the stent into a catheter, the rigidity of the metal cover impedes folding and thus limits the degree of compression. Moreover, the relatively rigid metal cover makes it difficult to insert the stent into tight vessel bends.

The aforementioned EP 1 620 047 B1 suggests applying a thin, perforated metal foil to a support framework. By the perforation of the film increased flexibility should be provided so that the film can easily adapt to vessel curvatures. As a disadvantage, the connection between the film and the stent has proven to be disadvantageous. The arrangement of the film on the grid structure is particularly complex and requires additional manufacturing steps. Moreover, there is a risk that the film will curl due to the proposed perforation, thereby increasing the risk of thrombosis and making it difficult to deliver the stent through a catheter. Specifically, it is provided in the known stent that the film has longitudinal slots which are aligned parallel to the longitudinal axis of the stent. These slots stretch more than the stent itself when compressing the stent. Because of this mismatch, the corrugation of the sheet may occur.

The object of the invention is to further develop a medical implant with a tubular lattice structure and a metallic cover such that the production is simplified and the handling is improved.

According to the invention, this object is achieved by the subject matter of patent claim 1.

Thus, the invention is based on the idea of specifying a medical implant with a tubular grid structure, which can be converted into a radially compressed and a radially expanded state. The lattice structure has lattice-limiting webs and at least one metallic cover element, which is closed in the circumferential direction of the lattice structure. The cover element has at least one annular edge portion and an annular or tubular cover portion which adjoins the edge portion and rests loosely on the lattice structure. The edge portion is integrally, in particular monolithically, connected to webs of the lattice structure, which are arranged in the region of the edge portion.

The one-piece design of the edge portion or generally of the cover with the grid structure, the manufacturing cost is significantly reduced. In addition, in this way, at least in the region of the edge portion, the wall thickness of the lattice structure can be reduced. In addition, a particularly strong and stable coupling is achieved with the integral connection between the grid structure and edge portion, which has a positive effect on the crimpability of the implant.

The metallic cover element is closed in the circumferential direction of the lattice structure. In other words, the cover element, in particular the annular edge section, surrounds the tubular grid structure in its entirety. The cover element can thus be designed to be cylindrical overall, wherein the cross-sectional diameter of the cover preferably corresponds to the cross-sectional diameter of the expanded lattice structure.

The cover element, in particular the cover section and / or the edge section, preferably has a multiplicity of pores, so that the cover element can follow an expansion and / or a longitudinal axial bending of the lattice structure. By the perforation or the arrangement of pores in the cover, the flexibility of the cover is increased. As a result, the cover element can adapt to different cross-sectional diameters of the lattice structure, which can be adjusted during the transition from the compressed state to the expanded state, or vice versa. Thus, in particular, it is avoided that the cover element curls strongly in the compressed state of the lattice structure, which would make it more difficult to feed the implant through a catheter.

Under pores are generally understood recesses in the cover, which have a defined geometry. The pores or recesses can lead to a porosity of at least 10%. The upper limit of porosity can be 90%. Preferably, the porosity is in a range of 20% -80%, more preferably 30% -50% and 50% -70%.

The pores can each be identically shaped, in particular diamond-shaped. In particular, the pores can be longer in the circumferential direction of the lattice structure than in the longitudinal direction of the lattice structure in a rest state of the cover element. In other words, the pores preferably have a diamond shape, with the diagonals running through the diamond being of different lengths. The longer diagonal runs in the circumferential direction of the lattice structure, whereas the relatively shorter diagonal runs in the longitudinal direction of the lattice structure. This increases the flexibility of the cover element in the circumferential direction of the lattice structure, so that the cover element can easily adapt to a change in diameter of the lattice structure. In this context, it is particularly preferred if the pores each have a ratio between the circumferential length and the axial length, which is greater than the ratio between the circumferential length and the axial length of the grid cells of the grid structure.

In principle, the cover element, which may be cylindrical overall, has two longitudinal ends. Both longitudinal ends may comprise an annular edge portion, which is connected to the lattice structure or proceeds integrally from the lattice structure. Between the edge portions extends the cover portion which rests loosely on the lattice structure.

For example, the cover portion may extend between two edge portions, which are each connected at a longitudinal end of the cover member with the webs of the lattice structure, which are arranged in the region of the associated edge portion. In this case, the cover, which is preferably cylindrical, at its longitudinal ends in each case emerge in one piece from the grid structure. In this way, a stable connection between the cover and the grid structure is ensured. At the same time, the cover section resting loosely on the lattice structure makes it possible for the cover element to adapt well to the curved lattice structure, particularly when the implant is inserted into a curved blood vessel. In particular, the cover section can compress longitudinally on a side facing the center of curvature and stretch longitudinally on a side averted from the center of curvature. This is facilitated by the fact that the cover section rests loosely on the lattice structure, ie can slide on the lattice structure.

Alternatively, it is possible that the cover member has a single annular edge portion which is integrally connected to the grid structure. By contrast, the cover section, which forms the cover element in one piece with the edge section, is arranged loosely on the grid structure. In other words, the cover portion forms an unconnected portion of the cover member or a free portion. The cover portion may thus slide on the lattice structure when transferred from the compressed state to the expanded state, or vice versa, or when the lattice structure is inserted into a curved blood vessel.

It can be provided that the cover has a free longitudinal end. The cover element can thus have on one side, in particular exclusively at one longitudinal end, an edge section formed in one piece with the grid structure, wherein the opposite longitudinal end is free or rests loosely on the grid structure or slides.

In particular, the free longitudinal end may form a point which is arranged radially inside the tubular lattice structure. The free longitudinal end may be closed, so that the cover has a total of a funnel-like shape. This allows the formation of a longitudinal-axial filter.

In general, the cover can form a radial and / or a longitudinal axial filter. A radial filter is formed when the cover member extends at least in sections over the circumference of the grid structure and has pores in this area. For example, when used in blood vessels, blood clots are filtered that can otherwise penetrate the lattice cells of the lattice structure. A longitudinal axial filter spans across the passageway provided by the grid structure. For example, it is possible to filter thrombi which drive with the blood flow through the blood vessel. A longitudinal-axial filter may be formed by the cover member when the cover member extends at least partially radially through the grid structure and has pores in this area. Preferably, the longitudinal-axial filter is formed by the cover portion of the cover member.

In preferred embodiments, the cover member may be disposed on an inside or outside of the grid structure. The arrangement of the cover on the inside has the advantage that the grid structure comes into contact with the vessel wall, which can lead to an improved anchoring of the implant in the blood vessel. The arrangement of the cover element on an outer side of the lattice structure may be advantageous if an aneurysm is to be shielded with the cover and additional irritation of the aneurysm neck is to be avoided. The cover provides a relatively large support surface, so that a punctual force, which can lead to an additional vascular irritation, is avoided.

The grid structure may have more than one cover element. In particular, the grid structure may comprise at least two cover elements, wherein at least one of the cover elements comprises a free longitudinal end. The free longitudinal end may be at least a cover member arranged adjacent in the longitudinal direction of the grid structure partially overlap. Overall, such a scale-like arrangement of cover elements can be provided. This increases the flexibility, in particular in the longitudinal direction of the grid structure. In this way, the implant can be inserted well into strongly curved blood vessels, whereby due to the overlapping of the cover elements, a full-surface coverage of the lattice structure is ensured.

It is also possible that the cover elements do not overlap.

The invention will be explained in more detail below on the basis of exemplary embodiments with reference to the accompanying schematic drawings. Show:

1 an unrolled view of a medical implant according to the invention according to a preferred embodiment, which has a cover member with two integrally connected to the grid structure edge portions;

2 a side view of the implant according to 1 in use;

3 an unrolled view of a medical implant according to the invention according to a further preferred embodiment with a plurality of cover elements, each having a free longitudinal end;

4 a side view of the implant according to 3 in use;

5 an unrolled view of a medical implant according to the invention according to another preferred embodiment, wherein the cover member has a free longitudinal end and extends over almost the entire length of the implant;

6 an unrolled view of a medical implant according to the invention according to a further preferred embodiment, wherein the cover member has a free longitudinal end and extends over a part, in particular half, of the grid structure;

7 an unrolled view of a medical implant according to the invention according to another preferred embodiment, wherein the cover member has a free longitudinal end, which is arranged outside the grid structure;

8th an unrolled view of a medical implant according to the invention according to another preferred embodiment, wherein the cover member has a tip formed as a free longitudinal end, which is disposed within the grid structure;

9 an unrolled view of a medical implant according to the invention in a further preferred embodiment, wherein the cover member has a tip formed as a free longitudinal end, which is arranged outside the grid structure;

10 the implant according to 9 in use; and

11 an unrolled view of a medical implant according to the invention according to a further preferred embodiment, wherein the cover has a circumferentially interrupted cover portion.

The following exemplary embodiments each show a medical implant, in particular a stent, of a tubular lattice structure 10 , The grid structure 10 is through grid cells 12 formed, wherein the grid cells 12 each through bars 11 are limited. The grid cells have a substantially diamond-shaped geometry, wherein the webs 11 Are S-shaped swinging. The grid structure 10 is integrally formed. In particular, the lattice structure 10 be made by laser cutting or a deposition process. Thus, the lattice structure 10 a uniform wall thickness or web thickness. Four bars each 11 limit a grid cell 12 ,

Furthermore, all embodiments described here have a cover 20 on, which is closed in the circumferential direction of the grid structure. The cover element 20 is therefore at least partially tubular. Concretely, the cover 20 be formed cylindrical or funnel-shaped. It is essential that at least one circumferential segment of the cover 20 closed is. In particular, at least one circumferential segment of the cover element 20 closed in a ring.

Specifically, it is provided that the cover 20 at least one annular edge portion 21 having. The edge section 21 is with the jetties 11 the lattice structure 10 connected. The connection is in one piece or monolithic. In other words, the cover element 20 , but especially the edge section 21 , integral with the grid structure 10 educated. The edge section 21 is with individual bars 11 the lattice structure 10 connected in the area of the edge section 21 are arranged. In this case, the edge portion 21 with individual bars 11 be connected to the grid structure, which in the region of the edge portion 21 are arranged or in the field of edge section 21 in the circumferential direction of the lattice structure 10 are arranged adjacent to each other. It is also possible that the edge section 21 with all the bridges 11 is integrally formed, which are adjacent to each other in the circumferential direction of the lattice structure 10 extend and in the area of the edge section 21 are arranged.

The cover element 20 further comprises an annular or tubular cover portion 23 which is at the edge section 21 borders. The cover section lies loosely on the lattice structure 10 on. At least the cover section lies in the compressed state of the lattice structure 10 loose on the grid structure 10 on. In an expanded state of the lattice structure 10 can the cover section 23 at least partially from the lattice structure 10 be spaced. The cover section 23 is integral with the edge portion 21 educated. In other words, the cover section forms 23 with the edge section 21 in one piece the cover 20 which in turn is integral with the grid structure 10 the implant forms.

For all embodiments, also applies that the cover 20 pore 25 having. The cover element 20 is thus perforated, with the perforation preferably over the entire cover 20 extends. In particular, pores are 25 both in the edge section 21 , as well as in the cover section 23 arranged. The pores 25 preferably have a diamond-shaped geometry. It is provided in particular that the diamond shape of the pores 25 rotated by 90 degrees to the diamond shape of the grid cells 12 is aligned. The pores 25 have in particular in the circumferential direction a greater longitudinal extent than in the longitudinal direction of the lattice structure. The diagonals, through the diamond-shaped pores 25 run, so are different lengths, with one in the circumferential direction of the lattice structure 10 extending diagonal longer than one in the longitudinal direction of the lattice structure 10 is running diagonal. At the grid cells 12 this is the other way around. The grid cells 12 also have a substantially diamond-shaped basic structure, wherein the longer rhombic diagonal runs in the longitudinal direction of the lattice structure and the shorter rhombic diagonal in the circumferential direction. The above applies in particular to the fully expanded state of the lattice structure 10 ,

In this context, it should be noted that the longitudinal extent of the lattice structure 10 in the accompanying figures from left to right, that is horizontal, shows. The circumferential direction is shown vertically in the drawing plane.

Regarding the webs 11 the lattice structure 10 can be provided that the webs 11 have different flexibilities. In particular, each diametrically opposed webs 11 a single grid cell 12 have the same flexibility, in turn, from the flexibility of the two other webs 11 the same grid cell 12 different. In other words, each form two opposite webs 11 the grid cell 12 a web pair, wherein each grid cell preferably comprises two pairs of webs. The webs of a pair of webs each have substantially the same flexibility. However, the bar pairs differ from each other due to different flexibilities. Overall, this achieves that the flexibility, in particular the flexural flexibility, of the lattice structure 10 is increased.

The cover element 20 is made of a metal. In particular, the cover 20 be formed of a nickel-titanium alloy. Since the cover 20 integral with the grid structure 10 is formed, has the lattice structure 10 the same material. The entire implant can thus be made in one piece from a nickel-titanium alloy.

The preparation of the implant according to the invention can be carried out by an etching process or a deposition process. As a deposition method, in particular a sputtering process is considered. It is also possible to use a combined sputter etching process. This will be the lattice structure 10 and the cover 20 formed in one piece on a blank. A pretreatment step can be provided, which comprises the application of a sacrificial layer, so that after the deposition and / or etching process a loose on the lattice structure 10 Overlying cover section 23 is trained. In particular, between the grid structure 10 and the cover member 20 In some areas, a sacrificial material can be arranged, which after deposition of the metal layer, the cover member 20 or the support section 23 forms, is removed. Thus, the cover portion becomes 23 not with the grid structure 10 connected, but is loosely on this. The removal of the sacrificial layer can be effected for example by an etching process.

The metallic cover element 20 is essentially formed like a film. This ensures a sufficiently high flexibility, so that the cover 20 Folds well during delivery of the implant through a catheter and thus is easily feasible through the catheter. In any case, the cover element 20 a much smaller wall thickness than the grid structure 10 on. Specifically, the wall thickness of the cover is 20 at most 20%, in particular at most 15%, in particular at most 10%, of the wall thickness of the lattice structure 10 ,

In the embodiment according to 1 is provided that the cover 20 two edge sections 21 having. The edge sections 21 are each at the longitudinal ends 22 . 24 of the cover 20 arranged. The longitudinal ends 22 . 24 extend in the circumferential direction of the lattice structure 10 completely around the grid structure 10 , In particular, the longitudinal ends 22 . 24 at the height of joints 13 of the bridges 11 the lattice structure 10 arranged. The edge sections 21 are each at one of the longitudinal ends 22 . 24 pronounced and form a peripheral segment of the cover 20 , which is formed substantially annular. Between the edge sections 22 . 24 the cover section extends 23 that is loose on the grid structure 10 rests. The cover section 23 has a considerably greater longitudinal extent than the two edge sections 22 . 24 on. Both the edge sections 21 , as well as the cover section 23 are regularly perforated or have a regular pattern of pores 25 on. The pores 25 are diamond-shaped.

The good adaptability of the cover 20 to the shape of the lattice structure 10 For example, in the compression or expansion of the lattice structure 10 or when using the grid structure 10 in tightly curved blood vessels, gets loose through the lattice structure 10 overlying cover 23 favored. 2 shows by way of example the implant according to 1 in use. It can be seen that the implant is arranged in a curved blood vessel. The curvature produces a relative compression in the longitudinal axial direction of the lattice structure 10 in the vicinity of the center of curvature and to an extension of the cover portion on a side of the lattice structure farther away from the center of curvature 10 , The implant is in accordance with 2 advantageous for closing an aneurysm 40 used.

A good adaptability to vessel curvatures can also be achieved in that several cover elements 20 longitudinally adjacent to the grid structure 10 are arranged. Such an embodiment is in 3 shown. It can be seen, the total of four cover elements 20 are provided, each having a peripheral portion 21 which is integral with the grid structure 10 connected is. Furthermore, the individual cover elements 20 one free longitudinal end each 24 on, together with the respective cover section 23 loose on the grid structure 10 rests. The connected edge sections 21 the individual cover elements 20 are spaced apart such that the cover sections 23 each the edge section 21 of the adjacent cover element 20 overlaps. In other words, the cover elements overlap 20 in the longitudinal direction of the lattice structure 10 , This results in a substantially scale-like arrangement of cover elements 20 ,

4 shows the arrangement of the implant with scale-like arranged cover elements 20 in use. It can be seen that the areas of the cover sections located near the center of curvature 23 slide over each other and thus the local compression of a region of the lattice structure 10 consequences. Conversely, the connected edge sections are removed 21 on the opposite side of the grid structure 10 , ie on the side of the lattice structure which is further away from the center of curvature 10 , from each other. So will the local strain of the lattice structure 10 balanced in the longitudinal direction. The overlapping area is preferably chosen so that even in the stretched state, a complete coverage of the grid structure 10 is guaranteed.

Instead of several cover elements 20 , each one free longitudinal end 24 can also have a single cover 20 be provided, which is a loose longitudinal end 24 includes. Such an embodiment is in 5 shown. It shows an implant that has a lattice structure 10 and one on the grid structure 10 arranged, in particular tubular, cover 20 includes. The cover element 20 has an annular edge portion 21 on, which is integral with the grid structure 10 is connected or is formed. Furthermore, the cover element comprises 20 a cover section 23 and so can on the grid structure 10 slide. In the embodiment according to 5 the cover element extends 20 almost over the entire grid structure 10 ,

It is also possible that the cover element 20 only part of the grid structure 10 covered. The embodiment according to 6 shows a variant, wherein the cover 20 only half of the grid structure 10 covered. In particular, covers the cover 20 only one circumferential segment of the lattice structure 10 , which has a longitudinal extent which is half the longitudinal extent of the entire lattice structure 10 equivalent.

As 7 shows, the cover 20 the lattice structure 10 also overlap. For example, it may be provided that the grid structure 10 a final series 14 of grid cells 12 having, with the cover 20 is formed in one piece. Specifically, the cover element 20 a border section 21 up, over the final row 14 the lattice structure 10 extends and with the jetties 11 the end row 14 is formed in one piece or monolithic. The cover section 23 extends over the end row 14 out so that the cover section 23 at least partially outside the grid structure 10 is arranged. With such a construction For example, by the cover 20 , in particular the cover section 23 , Aneurysms are covered without affecting the lattice structure 10 is arranged directly in the region of the aneurysm neck. This reduces the force on the aneurysm neck. Thus, the risk is counteracted that an excessive force on the aneurysm neck leads to further irritation of the tissue in this area.

In the following embodiments according to 8th to 11 is provided that the cover 20 , which may be generally formed like a foil, on an inner side of the lattice structure 10 located. The cover element 20 is integral with the grid structure 10 formed, in particular in the region of the edge portion 21 integral with the grid structure 10 connected. The cover section 23 can be at least partially and / or at least in the compressed state of the lattice structure 10 on an inner periphery of the lattice structure 10 be arranged. In particular, the cover is 20 in the embodiments according to 8th to 11 , arranged in the area of the passageway through the lattice structure 10 is limited. It can be provided that the cover 23 at least partially radially inward, ie in the direction of the longitudinal axis of the lattice structure 10 , is bent. For example, a longitudinal axial acting filter may be formed.

As in 8th For example, the cover section is shown 23 formed in a substantially funnel-shaped, wherein the cover portion 23 in a free longitudinal end 24 of the cover 20 passes over, this is essentially a tip 26 forms. The formation of the top 26 or the funnel shape of the cover section 23 can be done by a heat treatment. Alternatively, it is possible the free longitudinal end 24 purely mechanically to a point 26 to reshape, for example to gather. Overall, the cover section 23 have a corrugated shape.

In the embodiment according to 8th is the entire cover element within the grid structure 10 arranged. It is also possible that the cover element 20 at least partially outside the grid structure 10 is arranged as in 9 is shown by way of example. Thus, analogous to the execution according to 7 , the cover element 20 with a final series 14 the lattice structure 10 be integrally connected, wherein the cover portion 23 longitudinally axial over the grid structure 10 extends beyond. Overall, the cover 20 as it is in the 8th to 11 is shown, form a longitudinal axial filter, ie the flow of thrombi or similar concrements through the passageway of the lattice structure 10 To block.

Only materials or substances smaller than the pores 25 are, can the filter or the cover 20 happen.

10 shows an exemplary application for such a longitudinal-axial filter. The implant according to 9 For example, in an aneurysm 40 be arranged, wherein the longitudinal axial filter or the cover 20 closes the aneurysm entrance or aneurysm neck. Through the cover 20 It prevents thrombi that are in the aneurysm 40 form, in the adjacent blood vessels 41 be washed up. Moreover, the longitudinal axial filter or that with pores influences 25 provided cover 20 the blood flow into the aneurysm 40 , In particular, the blood flow is slowed down, allowing the blood within the aneurysm 40 can coagulate. This leads to a natural sclerotherapy of the aneurysm 40 , The grid structure 10 is completely within the aneurysm 40 arranged. The cover element 20 which forms the longitudinal-axial filter is at a proximal side of the lattice structure 10 arranged so that the longitudinal axial filter effectively closes the aneurysm neck. Due to the funnel-like or cone-like shape of the cover 20 is additionally advantageously achieved that the blood stream from a main vessel 42 low-turbulence in the secondary vessels 43 is directed.

11 shows a further embodiment of the implant according to the invention, in which the cover 20 forms a longitudinal axial filter. In the unrolled representation according to 11 it can be seen that the cover 20 in the area of the cover section 23 essentially has three covering wings. The cover section 23 is thus interrupted in the circumferential direction. By rolling the lattice structure 10 to a cylindrical basic body can from the three wings 27 of the cover section 23 a pyramidal filter are formed. The pyramidal filter has in the embodiment according to 11 a triangular base. In principle, other base surfaces can be provided. For example, 4, 5, 6 or more covering wings 27 the cover section 23 form, so that the pyramidal, longitudinal-axial filter has a triangular, a square, a pentagonal, a hexagonal or other polygonal base.

LIST OF REFERENCE NUMBERS

10

lattice structure

11

web

12

grid cell

13

junction

14

end row

20

cover

21

edge section

22

First longitudinal end

23

cover

24

Second longitudinal end

25

pore

26

Second, free longitudinal end

27

covering wing

40

aneurysm

41

blood vessel

42

main vessel

43

In addition vessel

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1620047 B1 [0001, 0003]

Claims (10)

Medical implant with a tubular lattice structure ( 10 ), which is convertible into a radially compressed and a radially expanded state, wherein the grid structure ( 10 ) Grid cells ( 12 ) limiting webs ( 11 ) and at least one metallic cover element ( 20 ), which in the circumferential direction of the grid structure ( 10 ) is closed, characterized in that the cover ( 20 ) at least one annular edge portion ( 21 ) and an annular or tubular cover portion ( 23 ), which at the edge portion ( 21 ) and loosely on the grid structure ( 10 ) rests, wherein the edge portion ( 21 ) in one piece, in particular monolithic, with the webs ( 11 ) of the lattice structure ( 10 ) connected in the region of the edge portion ( 21 ) are arranged. Implant according to claim 1, characterized in that the cover element ( 20 ), in particular the cover section ( 23 ) and / or the edge portion ( 22 ), a variety of pores ( 25 ) such that the cover element ( 20 ) a radial expansion and / or a longitudinal axial bending of the lattice structure ( 10 ) can follow. Implant according to claim 2, characterized in that the pores ( 25 ) in each case similar, in particular diamond-shaped, formed and in a resting state of the cover ( 20 ) in the circumferential direction of the lattice structure ( 10 ) longer than in the longitudinal direction of the grid structure ( 10 ) are. Implant according to claim 2 or 3, characterized in that the pores ( 25 ) each have a ratio between the circumferential length and the axial length that is greater than the ratio between the circumferential length and the axial length of the grid cells ( 12 ) of the lattice structure ( 10 ). Implant according to one of the preceding claims, characterized in that the cover portion ( 23 ) between two edge sections ( 21 ), each at a longitudinal end of the cover ( 20 ) with the webs ( 11 ) of the lattice structure ( 10 ) are connected in the region of the associated edge portion ( 21 ) are arranged. Implant according to one of the preceding claims, characterized in that the cover element ( 20 ) a free longitudinal end ( 24 ) having. Implant according to claim 6, characterized in that the free longitudinal end ( 24 ) forms a point which radially inwardly of the tubular lattice structure ( 10 ) is arranged. Implant according to one of the preceding claims, characterized in that the cover element ( 20 ) forms a radial and / or a longitudinal axial filter. Implant according to one of the preceding claims, characterized in that the cover element ( 20 ) on an inside or outside of the grid structure ( 10 ) is arranged. Implant according to one of the preceding claims, characterized in that the lattice structure ( 10 ) at least two cover elements ( 20 ), wherein at least one of the cover elements ( 20 ) a free longitudinal end ( 24 ), which extends in the longitudinal direction of the lattice structure ( 10 ) adjacently arranged cover element ( 20 ) at least partially overlapped.

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