WO2011076409A1

WO2011076409A1 - Medicinal implant and method for producing said type of implant

Info

Publication number: WO2011076409A1
Application number: PCT/EP2010/007889
Authority: WO
Inventors: Giorgio Cattaneo
Original assignee: Acandis Gmbh & Co. Kg
Priority date: 2009-12-23
Filing date: 2010-12-22
Publication date: 2011-06-30
Also published as: DE102009060280B4; DE102009060280A1

Abstract

The invention relates to a medicinal implant having a tubular-shaped grid structure (10) which can be converted into a radially compressed state and a radially expanded state, said grid structure (10) comprising webs (11) and a cover element (21) which is arranged on said webs (11). The invention is characterised in that said cover element (21) is essentially strip-shaped and has a first and a second longitudinal edge (23a, 23b) which are arranged at a distance from each other in the peripheral direction of the grid structure (10) and respectively have a main direction of orientation along the longitudinal direction of the grid structure (10). Said cover element (21) is securely connected to at least one web (11, 11a) of the grid structure (10) and the first and/or second longitudinal edges (23a, 23b) of the cover element (21) is/are detachably arranged on said grid structure (10) such that the first and/or second longitudinal edges (23a, 23b) lead to the outer periphery of the grid structure when said grid (10) structure converts into the radially expanded state in the peripheral direction. The invention also relates to a method for producing said type of implant.

Description

Medical implant and method of making such an implant

description

The invention relates to a medical implant according to the preamble of

Claim 1. Furthermore, the invention relates to a method for producing such an implant. An implant of the aforementioned type is known for example from WO 2006/125022 A2.

WO 2006/125022 A2 describes a stent with a lattice structure made of webs, wherein the lattice structure is provided with a tubular cover. The tubular cover is disposed on the outer periphery of the grid structure and completely covers cells of the grid structure bounded by the lands.

Such stents with a cover have disadvantages in terms of crimpability or compressibility. When compressing or crimping the stent or

In general implants, the cells of the lattice structure is deformed. The opening area spanned by the cells is thereby reduced. This also reduces the space available for the cover in the compressed state. The cover evades the deformation of the cells as the cover folds or curls. The folded or corrugated cover exerts a force on the

Lattice structure, which counteracts the compression force or the crimping of the lattice structure.

This has the disadvantage that the radial force with which the stent is transferred to the compressed state, ie the compression force, is relatively large. In particular, the stent has a relatively large radially outward restoring force due to the folded cover. The increased restoring force makes it difficult to deliver the stent through a catheter to the treatment site because the frictional force in the stent and the catheter inner wall is increased. This effect can be reduced with larger catheter diameters, with the disadvantage that smaller vessels can not be achieved.

Another disadvantage is that due to the strong deformation of the cover, in particular the folding of the cover in the cells of the lattice structure a Damage to the cover can not be excluded. The connection between the cover and the grid structure can be solved. There is a risk that detached material enters the body to be treated in an uncontrolled manner. For example, detached material can enter the bloodstream of a blood vessel, which on the one hand reduces the functionality of the stent and

on the other hand can cause the formation of thrombi.

When compressing the grid structure, portions of the cover may fold radially outwardly. This essentially creates one

untidy structure. This means that the frictional force existing between the stent and a catheter inner wall has different values at different locations of the stent. The supply force is not sufficiently reproducible, so that variations can occur within a product range. It is known that stents are oversized during manufacture, so that in the implanted state in a body cavity, a slight compression takes place. This is useful to achieve a secure anchoring of the stent in the vessel. In the case of the known stents, this can lead to a corrugation or folding of the cover in the implanted state. This entails the risk that dusty areas or fluid dynamic anomalies form, which promotes the formation of thrombi. Moreover, a corrugated structure of the cover can lead to injuries of the vessel wall.

WO 2006/125022 A2 also describes a stent having a grid structure made of webs and a tubular cover which completely surrounds the outer circumference of the stent. The cover has openings that break through the cover area by area. In particular, the known stent has a cover, which is formed overall tubular and forms at least in a central region of the stent a plurality of plates which are interconnected by bracing. Between the plates and the struts are the openings or the

arranged area-wise openings. In the compressed state of the known stent, the struts of the cover are arranged meandering. The essentially triangular plates of the cover are with a

Triangular edge fixed to one strut each. In the compressed state, the plates overlap due to the meandering arrangement of

Bracings. During the expansion of the stent, the meandering

Struts spread. This causes a relative movement between the plates, each about an end arc formed between two struts, twist. In the area of the end curves, a bending deformation is created. In order to prevent that the bending deformation leads to a folding or waves of the cover, it is expedient to equip the end sheets with a comparatively thin wall thickness. The risk of breakage of the end bends increases.

In practice it has been found that the known stent has disadvantages for the following reasons:

Since the cover is tubular and the grating structure completely engages around the outer circumference, the rotational movement of the struts about the end arches causes uncontrolled folding of the cover member in the transfer of the lattice structure from the expanded state to the compressed state. The cover folds in such a way that the cross-sectional diameter is disadvantageously increased in the compressed state.

The invention has for its object to provide a medical implant, which has a sufficient radial force in the implanted state and a relatively small cross-sectional diameter in the compressed state. In particular, the invention has the object to provide a medical implant with a cover, which has a sufficient degree of coverage in the implanted state and can be arranged to save space in the compressed state. Furthermore, the invention has for its object to provide a method for producing such an implant.

According to the invention, this object is achieved with regard to the medical implant by the subject-matter of patent claim 1 and with regard to the method by the subject-matter of patent claim 23 or 24.

The invention is based on the idea of specifying a medical implant having a tubular lattice structure which can be converted into a radially compressed and a radially expanded state. The grid structure comprises webs and at least one cover element arranged on the webs. The cover member extends at least partially over an outer periphery of the grid structure. In this case, the at least one cover element is substantially strip-shaped. The cover element comprises a first and a second longitudinal edge, which in

Circumferentially arranged circumferentially of the grid structure. The first and second longitudinal edges each have one along the longitudinal direction of the grid structure extending main orientation direction. The cover is firmly connected to at least one web of the grid structure. The first and / or second longitudinal edge of the cover is arranged loosely on the lattice structure, so that the first and / or second longitudinal edge slides in the circumferential direction on the outer periphery of the lattice structure at the transition of the lattice structure in the radially expanded state.

The invention is based on the idea of freeing at least one longitudinal edge, in particular the first and / or second longitudinal edge, on the outer circumference of the lattice structure

to arrange. In this case, the longitudinal edge extends mainly in the longitudinal direction of the tubular lattice structure. The main orientation direction of the longitudinal edge is therefore preferably arranged parallel to the longitudinal axis of the lattice structure. This ensures that the longitudinal edge in the transition of the lattice structure of

compressed in the expanded state and vice versa on the outer circumference in the circumferential direction moves. It is not excluded that the strip-shaped cover, for example, spirals around the longitudinal axis of the grid structure. The first and / or second longitudinal edge may also have a non-linear, for example, a corrugated, curved or jagged shape. In this case, the first and / or second longitudinal edge is oriented mainly, that is to say in its main orientation direction, along the longitudinal extension of the lattice structure.

Between the grid structure and the free or loose longitudinal edge is a

Provided relative movement, which is directed in the circumferential direction, ie on a circular path about the longitudinal axis of the grid structure. The relative movement between the first and / or second longitudinal edge and the grid structure prevents the cover element from folding in the crimped or compressed state of the grid structure. Rather, the cover is in both the crimped, as well as in the

expanded state arranged flat on the outer circumference of the lattice structure. This results in an increased crimpability of the medical implant or an advantageously reduced cross-sectional diameter of the medical implant in the compressed state. In contrast to known from the prior art implants with a cover, which in compressing the

Implant folds, the crimpability in the invention is substantially

irrespective of the material. In this case, the cover may overlap in the compressed state and / or in the expanded state. That means that

Covering at least in the compressed state, the outer circumference of the

Grid structure in the circumferential direction at least completely, in particular more than 100%, can cover. The cover member may wrap the grid structure several times in the compressed state. Since the cover element has at least one loose or free longitudinal edge, which slides on the outer circumference of the lattice structure, an influence on the radial force of the lattice structure is avoided.

Another advantage resulting from the loose or free arrangement and / or the second longitudinal edge of the cover element of the grid structure is that the strip-shaped cover element is not only displaceable in the circumferential direction, but also deflectable in the radial direction. This means that the loose edge, namely the first and / or second longitudinal edge in the radial direction with respect to the tubular lattice structure is movable. Advantageously, the radial deflection takes place without damage and / or substantial stress or distortion of the

Cover. The radial deflection of the cover is reproducible. This allows, for example, the passage of a catheter through the wall of the medical implant, wherein the wall is formed by the grid structure and the cover. Furthermore, the blood flow from laterally branching blood vessels can be achieved in this way. The cover can therefore, if necessary, openings of the lattice structure, in particular cell openings release.

In a preferred embodiment of the medical invention

Implant is the first longitudinal edge of the cover with the web fixed

connected. Specifically, it is advantageously provided that the first longitudinal edge of the

Covering firmly connected to the web of the lattice structure and the second longitudinal edge is arranged loosely on the lattice structure. In this way, the loose portion or the free edge arranged on the lattice structure extends in a circumferential direction, so that compression of the medical implant is facilitated.

In an advantageous embodiment, at least one further cover element is provided, which in the circumferential direction of the grid structure to the cover

arranged adjacent and formed substantially strip-shaped. The further cover element comprises a first and second longitudinal edge, which in

Circumferentially arranged circumferentially of the grid structure. The first and second longitudinal edges of the further cover element each have a main orientation direction running along the joint direction of the lattice structure. The further cover element is fixedly connected to at least one further web of the lattice structure. The first and / or second longitudinal edge of the further cover element is arranged loosely on the lattice structure, so that the first and / or second longitudinal edge the further cover member during the transition of the lattice structure in the radially expanded state in the circumferential direction on the outer periphery of the lattice structure slides.

In general, the same advantages apply to the further cover element, which also apply to the cover element described above. In addition, the at least one further cover element simplifies the complete covering of the lattice structure. Preferably, at least two cover elements, namely the cover and the further cover, provided in the circumferential direction on the

Outer periphery of the grid structure are arranged adjacent. As a result, at least two second longitudinal edges over the circumference of the lattice structure

provided, which rest freely or loosely on the grid structure. The second

Longitudinal edges of the cover, are arranged freely or loosely in the circumferential direction of the grid structure. In other words, the cover, in particular the cover and the further cover, in the circumferential direction of

Grid structure open. The possibilities for the passage of a catheter through the wall of the medical implant are thus increased.

Advantageously, the first longitudinal edge of the further cover element is firmly connected to the further web. Analogously to the connection of the first longitudinal edge of the cover element to the web, the connection of the first longitudinal edge of the further cover element to the further web enables a simplified compression of the implant, the second longitudinal edge of the further cover element sliding on the outer circumference of the lattice structure.

In the radially compressed state of the grid structure, the cover element may overlap the further cover element in the circumferential direction. The cover member may slide in the transition from the expanded or fabricated state of the grid structure in the compressed state on the other cover. A folding of the cover is thus avoided. In this way, a relatively large outer surface is provided in the expanded state of the lattice structure. This means that a large part of the lattice structure can be covered by the cover element and the further cover element. At the same time, a relatively small cross-sectional diameter is provided in the compressed state of the lattice structure. The

telescopic, surface overlap of the cover with the other

Cover element thus combines the advantages of a flat, in particular

closed, cover of the lattice structure in the expanded state with a increased crimpability of the medical implant or a relatively small cross-sectional diameter of the medical implant in the compressed state.

It is particularly preferred if the second longitudinal edge of the cover element in the radially compressed state of the lattice structure overlaps the first longitudinal edge of the further cover element in the circumferential direction of the lattice structure. In other words, the cover and the further cover extend in

Circumferential direction preferably in the same orientation. Advantageously, therefore, the first and second longitudinal edges are each arranged alternately in the circumferential direction of the grid structure. By aligning the cover element and the further cover element in each case in the same orientation over those in the circumferential direction of the lattice structure, the compression of the medical implant is advantageously simplified.

It is additionally possible for the cover element to overlap the further cover element in the radially expanded state of the grid structure. The cover element can thus be arranged in the expanded state with respect to the further cover element such that the free, second longitudinal edge of the cover element is arranged on or under the second cover element. This is in the circumferential direction of the

Grid structure in the expanded state formed a gapless cover. Alternatively, it is conceivable that the free, second longitudinal edge of the cover is arranged in the expanded state of the grid structure in the circumferential direction spaced from the first longitudinal edge of the further cover. Concretely, between the

Covering element and the other cover in the expanded state a longitudinal gap may be formed.

In a preferred embodiment of the medical implant, the cover element forms an overlap region with the further cover element which is smaller in the radially expanded state of the lattice structure than in the radially compressed state. The first and / or second longitudinal edge of the cover thus slides on or under the other cover over the outer periphery of the

Grid structure in the circumferential direction. The overlap area formed in this case is greater in the compressed state than in the expanded state. In the expanded state, the overlap area can assume the value zero. In this case, the first or second longitudinal edge of the cover is applied to the second or first longitudinal edge of the other cover. It is also possible that the overlap area in the expanded state assumes negative values. In this case is between the first or second longitudinal edge of the cover and the second or first longitudinal edge of the further cover a longitudinal gap formed. The cover and the further cover are spaced from each other over the

Outside perimeter of the grid structure arranged distributed. It is not excluded that the overlap area in the compressed state of the grid structure is zero or assumes negative values. This is expedient if, in the expanded state of the lattice structure, separate, strip-shaped covered areas are to be formed.

The length of the overlap region corresponds to the shortest distance between the second longitudinal edge of the cover element and the first longitudinal edge of the further cover element. The distance follows the curvature of the tubular

Grid structure in the circumferential direction. The length measurement will be the shortest

Distance between the second longitudinal edge of the cover and the first

Longitudinal edge of the other cover element used as a basis.

It is preferably provided that in the compressed state of the lattice structure, the overlapping region is 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 50%, in particular at least 60%, in particular at least 70%. , in particular at least 80%, in particular at least 90%, of the width of the further covering element in the circumferential direction. In other words, the distance between the first longitudinal edge of the cover member and the first longitudinal edge of the further cover member at most 90%, in particular at most 80%, in particular at most 70%, in particular at most 60%, in particular at most 50%, in particular at most 40%, in particular at most 30%, in particular at most 20%, in particular at most 10%, the width of the first cover. In this way, it is ensured that in the expanded state of the lattice structure a sufficient, in particular complete or gapless, cover is formed.

It is possible for the cover member to overlap more than one cover member. For example, the cover 2, 3 or 4 more

Overlap cover elements.

The cover can be aligned in the radially expanded state of the grid structure with the other cover. In other words, the overlap area of the cover with the other cover in the expanded state zero or less than zero. For example, the cover element may be arranged in the radially expanded state of the grid structure with the further cover member in abutment. In particular, this concerns the longitudinal edges of the cover element or of the further cover element. Advantageously, in the expanded state of the grid structure, the second longitudinal edge of the cover element can be arranged in abutment with the first longitudinal edge of the second cover element. In this respect, the cover element and the further cover element are aligned with each other. The aligned

Arrangement can also be given by the fact that the cover is spaced from the other cover. It is between the

Covering and the other cover a longitudinal gap formed. The longitudinal gap extends in particular from the second longitudinal edge of the

Covering the first longitudinal edge of the other cover.

The aligned arrangement of the cover with the other cover ensures a uniform wall thickness of the entire, the grid structure covering, cover. By the flush arrangement of the cover with the other cover is advantageously a flat cover on the

Outer periphery of the lattice structure provided, which has a substantially constant wall thickness.

The second longitudinal edge of the cover can in the expanded state of

Grid structure be spaced from the first longitudinal edge of the further cover and form a longitudinal gap. The longitudinal gap can be in

Circumferential direction of the lattice structure have a width which is at least 0.1 times, in particular at least 0.2 times, in particular at least 0.3 times, in particular at least 0.4 times, in particular at least 0.5 times times, in particular at least 0.8 times, in particular at least 1 times, the width of the other cover in the circumferential direction corresponds. The

Ratio between the total width of all longitudinal slots in the circumferential direction in the expanded state of the lattice structure to the entire circumference of the lattice structure is at least 0.1, in particular at least 0.2, in particular at least 0.3, in particular at least 0.4, in particular at least 0.5. Through the longitudinal gap, in the expanded state between the cover and the other

Cover is formed, is a continuous lateral flow,

For example, in side branches of a hollow body vessel, guaranteed. Furthermore, it is achieved by the longitudinal gap in the expanded state that the medical Implant in the compressed state a further reduced

Cross-section diameter occupies. At the same time by the aforementioned

Ratio values make it possible to ensure adequate coverage of the lattice structure in the expanded state, for example by efficiently fulfilling the function of a flow diverter, ie blocking blood flow into an aneurysm.

In a further preferred embodiment of the medical implant, the cover element and / or the further cover element has at least one transverse edge, which is arranged loosely on the outer circumference of the lattice structure, so that the transverse edge in the longitudinal direction of the transition of the lattice structure from radially compressed to radially expanded state slides on the outer periphery of the grid structure. During the transition of the lattice structure into the radially compressed state, a change in length of the lattice structure frequently occurs. In particular, the grid structure can extend in the axial direction. This concerns especially the cells of the lattice structure, which extend in the longitudinal direction of the lattice structure during the transition from the expanded to the compressed state of the lattice structure. By loosely arranged on the outer circumference of the grid structure transverse edge of the

Covering element or the further cover element is an influence of the cover or the further cover member is reduced in the transition of the lattice structure from the radially expanded in the radially compressed state. Specifically, an elongation of the cover member and the further cover member in

Longitudinal direction of the lattice structure during the transition from the radially expanded into the radially compressed state of the lattice structure avoided.

Furthermore, the loose transverse edge can be advantageous if in the longitudinal direction of the

Grid structure a plurality of cover elements are provided. These can be in

overlap expanded state of the grid structure to ensure a secure and complete coverage of the grid structure. It is not excluded that the cover, i. extends through the cover or the further cover formed sections, a total of a portion of the grid structure. Within this subarea a gapless cover is created by the overlapping of the cover elements with each other. This is true for both

Overlap in the longitudinal direction of the lattice structure, as well as for overlap in

Circumferential direction of the lattice structure. The covering element and / or the further covering element can be connected at points to the grid structure, in particular the web and / or the further web. Due to the selective connection of the cover or the other

Covering the web or the other web a folding or waves of the cover or the individual cover is avoided in the transition of the lattice structure in the compressed state. It is particularly advantageously provided that the cover or the further cover each having a connecting line extending in the longitudinal direction of the grid structure. The connecting line may be formed by the first or second longitudinal edge. It is also possible for the connecting line between the first and second longitudinal edges to extend in the longitudinal direction of the covering element or of the further covering element. For example, the connecting line can extend centrally over the cover element or the further cover element. In any case, the connecting line crosses webs of the lattice structure. At least one crossover point between the

Connecting line and at least one web of the grid structure, the cover or the further cover is connected to the grid structure. Such a connection is referred to as points in the context of this application.

The cover element and / or the further cover element are preferably connected to at least two webs arranged adjacent to one another in the longitudinal direction of the lattice structure. In this way, it is ensured that the second longitudinal edge of the cover or of the further cover element moves in the circumferential direction over the grid structure when the grid structure from the compressed into the

expanded state or vice versa is transferred. The at least two-fold connection of the cover element or of the further cover element with the

Lattice structure also increases the stability of the entire cover.

The cover element and / or the further cover element can be connected in the area of a crossing point of the lattice structure by at least two webs being connected to one another. In general, the transition from

compressed in the expanded state of the grid structure and vice versa between longitudinally adjacent crossing points a relative movement, which is directed mainly in the longitudinal direction. Through the connection of the

Covering element or the further covering element with the crossing point is thus a differently directed relative movement, which may, for example, lead to a twisting or twisting of the cover or the other cover, avoided. In general, the crossing point has a constant Geometry on. This means that the lattice structure in the region of the crossing point in the transition from the radially compressed to the radial

expanded state substantially not deformed. Preferably, the

Junction arranged at the crossing point. Since the point of intersection is essentially not deformed per se at the transition of the lattice structure from the compressed to the expanded state, there is essentially no deformation of the connection point and thus no deformation of the cover element or further cover element. Although the intersection point migrates in the longitudinal direction and on the circumference of the lattice structure during the transition from the radially compressed to the radially expanded state of the lattice structure. On the other hand, relative to the cell or relative to the webs of the lattice structure, the point of intersection or the local position of the intersection point remains essentially stable. This stability is transferred to the

Covering element or the further cover element, which is connected at the intersection with the grid structure. Concretely, this prevents the

Covering element or the other cover at the transition of the lattice structure from the compressed to the expanded state, or vice versa, deformed.

In general, the cover element or the further cover element

is advantageously firmly connected to areas of the grid structure, in the

Substantially have no deformation when the lattice structure is transferred from the radially compressed to the radially expanded state or vice versa.

The cover and / or the further cover are preferably flexible. In particular, the radial deflectability of the cover element or of the further cover element is thus improved. The passage of a catheter or the passage of a fluid flow through the covered by the cover and / or the further cover cell cells of the grid structure is thus facilitated.

The cover member and / or the further cover member may further include a

Structuring, in particular pores or a perforation. Such structuring may be with respect to the attachment of endothelial cells, the

so-called endothelialization, be beneficial. Moreover, the structuring counteract stresses in the cover or in the other cover, which act through the transition of the lattice structure from the radially compressed to the radially expanded state or vice versa. When the state of the lattice structure changes, that is to say when the lattice structure changes from the radially compressed to the radially expanded state and vice versa, the distance between two points of intersection arranged in the longitudinal direction of the lattice structure changes. In particular, the transition from the radial

expanded in the radially compressed state of the grid structure causes an extension of the distance between adjacent in the longitudinal direction of the grid structure crossing points. This can lead to an extension or expansion of the cover or the other cover. An extension or expansion of the receiving element can also be created by positioning the grid structure in a curved body cavity. In particular, arranged on the outer curvature of the grating structure may have an elongation. By structuring the extension of the

Covering element and the other cover facilitates.

The structuring preferably comprises pores which are diamond-shaped. The diamond-shaped pore geometry advantageously comprises two in

Longitudinal direction of the lattice structure opposite arranged corners, which have a relatively large angle. For example, the angle may be at least 90 °, in particular at least 120 °, in particular at least 130 °, in particular at least 140 °, in particular at least 150 °, in particular at least 160 °, in particular at least 170 °. It is also possible that the angle which in the longitudinal direction of the oppositely arranged corners of the diamond-shaped pore comprises approximately or almost 180 °. The pore is thus slit-shaped, wherein the slot has a longitudinal extent, extending in the circumferential direction of the

Lattice structure extends. The relatively large angle of the corners of the pores arranged opposite one another in the longitudinal direction of the lattice structure allows a particularly large extension of the cover element or of the other

Covering element, wherein at the same time an expansion of the material of the cover or of the further cover is effectively avoided. Since the covering element or the further covering element has a free, second longitudinal edge which slides on the lattice structure, such large corner angles are possible without causing a distortion of the pores in the change of state of the lattice structure.

In general, the corner angles of the diamond-shaped pores may form another angle than the webs connected at a crossing point of the lattice structure. In other words, the pore angle of the cover element or of the further cover element can be different with respect to the cell angle of the lattice structure. In particular, it is advantageous if the cell angle is substantially smaller than the pore angle.

Preferably, the cover and / or the further cover are welded or glued or integrally formed with the web and / or the other web of the grid structure. The manufacture of the medical implant is simplified in this way.

In a further preferred embodiment of the medical implant, the covering element with the at least one further covering element is distributed uniformly over the outer circumference of the lattice structure. Specifically, it is provided that the cover and the at least one further cover are each arranged at the same distance over the outer periphery of the grid structure. This ensures that the medical implant compresses and expands evenly. In particular, it is ensured that in the compressed state in the formation of overlapping areas, the wall thickness of the entire

Cover is substantially constant or at least equidistant along the outer circumference of the lattice structure is the same.

The cover element may, individually or together with the at least one further cover element, completely cover the outer circumference of the lattice structure. Alternatively, it is also possible that the outer circumference of the lattice structure has a partial area which is covered completely with the cover element individually or the cover element and the further cover element. Altogether, the individual covering element or the covering element with the at least one further covering element can form a cover which covers the lattice structure partially or completely.

envelops. This applies both to the compressed state of the lattice structure and to the expanded state.

In the expanded state of the grid structure, the width of the cover element and / or the further cover element can be at least 1 times, in particular at least 1, 1 times, in particular at least 1.2 times, in particular at least 1.3 times, in particular at least 1.4 times, in particular at least 1.5 times the value of the circumference of the lattice structure, so that the cover and / or the further covering element wraps around the lattice structure. For example, in the case of a single cover element, the width of the cover element is 10% greater than the circumference of the lattice structure, if the width of the cover Covering element corresponds to 1, 1 times the value of the circumference of the grid structure. The same applies to the other factors mentioned above, each of which corresponds to an enlarged width of 10%, 20%, 30%, 40%, 50%. In the case of several cover elements (cover element and at least one further cover element), the sum of the widths of all cover elements is 10% greater than the circumference of the lattice structure, if the width of the cover elements is 1, 1 times the value of

Scope of the grid structure corresponds. The same applies to the other factors mentioned above, each of which corresponds to an enlarged width of 10%, 20%, 30%, 40%, 50%. The sum of the width of all cover elements may be referred to as the cumulative total width.

With the factor 1, the width of the single cover element or the cumulative width of all cover elements corresponds to the circumference of the grid structure. For a single cover element, the longitudinal edges are in the expanded state

arranged side by side, in particular arranged on impact.

In the compressed state of the grid structure, the width of the cover member and / or the further cover member at least 3 times, in particular at least 4 times, in particular at least 5 times, in particular at least 6 times, in particular at least 7 times, in particular at least 8 times, in particular at least 9 times, in particular at least 10 times, in particular at least 12 times, in particular at least 14 times, in particular at least 16 times, in particular at least 18 times, in particular at least 20 times the value of

Correspond to the size of the grid structure. This ensures safe, in particular complete, coverage in the expanded state. For several

Covering elements, which are arranged on the lattice structure in the circumferential direction, corresponds to the width of the cover elements of the cumulative total width of all

Cover. In the compressed state, the width of the entire cover, ie the total width of all cover elements in total, at least three times in particular at least 4 times, in particular at least 5 times, in particular at least 6 times, in particular at least 7 times, in particular at least 8 times, in particular at least 9 times, in particular at least 10 times, in particular at least 12 times, in particular at least 14 times, in particular at least 16 times, in particular at least 18 times, in particular at least 20 times the value of the size of the lattice structure. In the expanded state, ie expanded extent, starting from the above-mentioned multiple overlap of the circumference, a width of the entire cover, ie the total width of all cover elements can be set in total, which corresponds at least to the extent of the lattice structure in the expanded state or preferably at least 10th %, at least 20%, at least 30%, at least 40%, at least 50% greater than the size of the lattice structure.

In the case of a single cover element, the overlapping region in the compressed state, which is delimited by the first and second longitudinal edges, can be determined by the cover element being pressed at least twice, in particular at least three times, in particular at least four times, in particular at least five times , in particular at least 6 times, in particular at least 7 times, in particular at least 8 times, in particular at least 9 times, in particular at least 10 times, in particular at least 12 times, in particular at least 14 times, in particular at least 16 times, in particular at least 18 times, in particular at least 20 times, wound or wrapped around the circumference of the lattice structure.

The above-mentioned width of the cover members (cumulative total width) and the width of the single cover member refers to the ratio between the absolute width of the cover members and the individual

Covering element and the respective circumference (compressed / expanded) of the

Lattice structure. One can therefore speak of a relative breadth. The diameter or circumference of the lattice structure in the compressed state

given and corresponds, for example, the inner diameter of the delivery system, for example. The catheter used for implantation. The diameter or circumference of the lattice structure in the expanded state is in lattice structures

Shape memory materials are also predetermined and determinable by the conditioning. In mechanically expandable grating structures, eg. At

Balloon-expandable lattice structures can, for example, be used by the manufacturer for predetermined expansion diameter for determining the expanded circumference. The person skilled in the art can adjust the dimensions of the lattice structure in the compressed and in the expanded state in order to obtain the above-mentioned

Coverage widths or overlaps. In general, the width of the cover element or of the further cover element refers to the extent of the cover element or of the other

Covering element in the circumferential direction of the grid structure.

Preferably, a plurality, in particular at least two, further cover elements are provided, which are arranged adjacent in the circumferential direction of the lattice structure and in the radially compressed state of the lattice structure overlapping. The several other cover elements can overlap in a telescopically planar manner. The medical implant can thus have a total of a plurality of cover elements, namely the cover and a plurality of other cover elements, which overlap in the compressed state of the lattice structure and slide telescopically flat over each other in the expansion, so that a uniform cover is clamped. Preferably, the number of cover elements, that is, the total number of the cover element with the other cover elements corresponding to

Circumferentially arranged circumferentially of the grid structure to each other, the number of cells of the grid structure, which are arranged adjacent to each other in the circumferential direction of the grid structure.

According to a secondary aspect, the invention is based on the idea of specifying a method for producing a previously described medical implant, which comprises the following steps:

Providing a raw form of the lattice structure;

Applying a sacrificial layer comprising a photoresist and / or a sacrificial foil to the grid structure;

Patterning the sacrificial layer, exposing a structure of junctions (13) of the grid structure (10);

Applying a cover layer on the sacrificial layer and the

Connecting points (13) such that the cover layer to the

Connecting points (13) is connected to the grid structure (10) and forms a cover (21); and

Removing the sacrificial layer to form a free longitudinal edge (23b) of the cover member (21).

The structuring of the sacrificial layer is preferably carried out by etching. Specifically, when using a photoresist, the photoresist can first be exposed and etched at the exposed locations. The application of the cover layer takes place preferably by a sputtering method. The removal of the sacrificial layer can also be done by etching.

The raw form of the lattice structure may comprise a planar lattice structure or a tubular lattice structure. In the case of a flat lattice structure, this can be converted into the tube shape after removal of the sacrificial layer.

A further, subsidiary aspect of the invention provides a method for producing a medical implant according to claim 1, comprising the following steps:

Providing a planar grid structure;

Providing a cover member;

Forming the lattice structure into a tubular shape, wherein two longitudinal ends of the lattice structure are circumferentially butted; Placing the cover member on the abutting longitudinal ends; and

Connecting the two longitudinal ends of the grid structure with each other and simultaneously with the two longitudinal ends of the grid structure with the

Cover.

The method has the advantage that the cover element and the two longitudinal ends of the grid structure are connected to each other simultaneously by a single manufacturing process. The production of the medical implant from a flat lattice structure is thus simplified.

The invention will be described below with reference to embodiments

With reference to the accompanying schematic drawings explained in more detail.

Show in it

1 is a plan view of a section of an outer periphery of a medical implant according to the invention according to a preferred embodiment in the expanded state.

FIG. 2a is a cross-sectional view of the medical implant according to FIG

Fig. 1 in the expanded state; a cross-sectional view of the medical implant of Figure 1 in the compressed state. a plan view of a section of the outer periphery of the medical implant of FIG. 1 in the compressed

Status; a cross-sectional view of the medical implant of Figure 1 in the implanted state. a cross-sectional view of a medical implant according to the invention according to a further preferred embodiment in the expanded state; a cross-sectional view of the medical implant of Figure 5a in the compressed state. a plan view of a section of an outer periphery of a medical implant according to the invention according to a further preferred embodiment;

FIGS. 7a, 7b each show a cross-sectional view of a medical implant in different method steps of a production method according to the invention in accordance with a preferred embodiment;

FIGS. 8a-8c show a cross-sectional view of a medical implant in FIG

different process steps of a manufacturing method according to the invention according to another preferred

Embodiment;

9a is a cross-sectional view of a medical invention

Implant according to another preferred

Embodiment in the expanded state;

9b shows a cross-sectional view of the medical implant according to FIG

Fig. 9a in the compressed state; 10 is a partial cross-sectional view through a cover of a

inventive medical implant according to a preferred embodiment in the compressed state;

Fig. IIa a cell in the compressed state with one of the cell

associated cover;

FIG. IIb shows the cell according to FIG. IIa in the expanded state; FIG.

Fig. 12a shows a cell with a cell associated with the cover

modified form in the expanded state and

Fig. 12b, the cell of FIG. 12a in the compressed state.

As shown in FIG. 1, the medical implant comprises a grid structure 10 and a cover 20. The grid structure 10 has a plurality of webs 11 which delimit cells 15. Each cell 15 is essentially delimited by two webs 11, wherein the webs 11 each have a hat-like or double-S-like shape. Each cell 15 are also each associated with two crossing points 12, in which two webs 11 are connected to each other. The crossing points 12 are arranged in the longitudinal direction of the lattice structure 10 in alignment with each other.

In this connection, it is pointed out that the longitudinal direction of the lattice structure 10 in FIGS. 1, 3 and 6 extends horizontally in the plane of the drawing. In FIGS. 2 a, 2 b, 4 - 5 b and 7 a - 9 b, the longitudinal direction or the longitudinal axis of the lattice structure 10 extends perpendicularly to the plane of the drawing. It should also be pointed out that the cover 20 can be arranged both on the outer circumference and on the inner circumference of the lattice structure 10. In the embodiments described in detail, the cover 20 and the

Cover elements 21, 22, 22 'are arranged on the outer circumference of the lattice structure 10. Analogously, it can be provided in further exemplary embodiments that the cover 20, in particular the cover elements 21, 22, 22 ', are arranged on the inner circumference of the lattice structure or connected to the inner circumference of the lattice structure. The arrangement of the cover 20 on the inner circumference of

Lattice structure 10 has the advantage that the lattice structure 10 or generally the medical implant generally has improved adhesion to a vessel wall.

The cover 20 according to FIG. 1 comprises a cover element 21 and two further cover elements 22, 22 '. For reasons of clarity, the cover element 21 will hereinafter be referred to as the first cover element 21 and the two further cover elements 22, 22 'as the second cover element 22 and the third cover element 22'. In general, it is provided that the cover 20 according to the embodiment of FIG. 1, a plurality of cover 21, 22, 22 ', wherein the cover 21, 22, 22', ie the first cover 21, the second cover 22 and the third cover 22 ', each having a similar design. Specifically, the first cover 21 and the second cover 22 may be formed identical in terms of geometric design. It is also possible for the first and second cover element 21, 22 or further cover elements 22 'to be geometrically or relative to one another with respect to the materials used

differ.

The cover elements 21, 22, 22 'are formed like a film. This means that the cover elements 21, 22, 22 'are each flexible or comprise a flexible material or a flexible geometry, for example a structuring. Due to the overlapping of the cover elements 21, 22, 22 'in the compressed state, it is also possible that the cover elements 21, 22, 22' have a stiff or rigid or inflexible material. The cover elements 21, 22, 22 'furthermore have a structuring in the form of pores 26. The pores 26 each form a regular pattern on the cover element 21, 22, 22 '. An unstructured or smooth design of the cover 21, 22, 22 'is also conceivable.

The cover elements 21, 22, 22 'are strip-shaped. The cover elements 21, 22, 22 'have a longitudinal extent that is greater than the transverse extent. In this case, the longitudinal extent is aligned parallel to the longitudinal extent of the lattice structure 10, whereas the transverse extent is aligned in the circumferential direction of the lattice structure 10. In particular, the cover element 21, 22, 22 'comprises a first longitudinal edge 23a and a second longitudinal edge 23b. The first and second longitudinal edges 23a, 23b extend in the longitudinal direction of the lattice structure 10. Further, the

Covering element 21, 22, 22 'has a first transverse edge 25a and a second transverse edge 25b. The first and second transverse edges 25a, 25b extend in the circumferential direction of the lattice structure 10 in each case. Specifically, the first and second transverse edges 25a, 25b extend in each case perpendicular to the first and second longitudinal edges 23a, 23b. The cover 21, 22, 22 'forms a total of a rectangular shape. It is also possible for the first and second longitudinal edges 23a, 23b and / or the first and second transverse edges 25a, 25b to have curved or differently shaped shapes. It is essential that the main orientation direction of the longitudinal edges 23a, 23b in the longitudinal direction of

Lattice structure 10 extends. Overall, the cover 21, 22, 22 'also have a trapezoidal shape or dragon shape or rounded shape, wherein the

Main orientation direction of the longitudinal edges 23a, 23b of the longitudinal direction of

Lattice structure 10 follows. Furthermore, the strip-shaped cover element 21, 22, 22 'can spiral around the lattice structure 10.

In the embodiment according to FIG. 1, the first longitudinal edge 23a of the

Covering element 21, 22, 22 'connected to a web 11 of the lattice structure 10.

Specifically, the first longitudinal edge 23a of the first cover member 21 is fixedly connected to a first web IIa of the lattice structure 10. The first longitudinal edge 23a of the second cover element 22 is connected to a second web 11b of the lattice structure 10. The first and the second web IIa, I Ib are arranged in the circumferential direction of the grid structure 10 spaced. In particular, the first and second webs IIa, Ib are arranged adjacent to one another in the circumferential direction of the lattice structure. This means that the first web I Ia and the second web IIb are each assigned adjacent cells 15 in the circumferential direction. In the longitudinal direction of the lattice structure 10, a plurality of first webs I Ia are provided, which are assigned in the longitudinal direction of adjacent cells 15 and connected to each other at a crossing point 13. The same applies to the second webs IIb in the longitudinal direction of the lattice structure 10th

The cover elements 21, 22, 22 'are connected according to FIG. 1 at the crossing points 12, each with a web 11. In particular, connection points 13

provided, which are each associated with a first longitudinal edge 23a of the cover 21, 22, 22 '. The connection points 13 are each in the range of one

Intersection point 12 of the lattice structure 10 is arranged. The longitudinal edges 23a of the cover elements 21, 22, 22 'are thus selectively connected in the region of the intersection points 12 with the lattice structure 10 or the webs 11 of the lattice structure 10. The second longitudinal edge 23b of the first cover member 21 and the second

Covering element 22 is respectively arranged freely or loosely on the lattice structure 10.

In the compression of the lattice structure 10 or in the transfer of the

Lattice structure 10 in the compressed state becomes the opening area of the cells 15 reduced. In particular, the circumferential extent of the cells 15 is reduced in the transition of the lattice structure 10 in the compressed state. At the same time, the longitudinal extent of the cells 15 is increased. The change in length of the cells 15 is preferably substantially smaller than the change in the circumferential extent. During the transition of the lattice structure 10 into the compressed state and the resulting shortening of the circumferential extent of the cells 15, the second longitudinal edges 22b of the cover elements 21, 22, 22 'slide on the outer circumference of the

Grid structure 10. The distance between the free, second longitudinal edge 23b of the first cover 21 is reduced to the first longitudinal edge 23a of the second, adjacent cover member 22 until the first cover 21 overlaps the second cover 22 and the second longitudinal edge 23b overlaps the second cover 22 pushes. The first cover 21 thus overlaps the second cover 22 telescopically in a planar arrangement in the transfer of the lattice structure 10 in the compressed state.

It is also possible for the cover elements 21, 22, 22 'to be connected to the grid structure 10 in a middle region of the first longitudinal edge 23a. The outer regions of the longitudinal edge 23a, ie directly from the transverse edges 25a, 25b

outgoing areas of the longitudinal edge 23a, loose or free on the

Grid structure 10 may be arranged. If a plurality of cover elements 21, 22, 22 'are arranged in the longitudinal direction of the lattice structure 10, these may be included

Transfer of the lattice structure 10 advantageously overlap from the compressed state to the expanded state. The expansion of the lattice structure 10 preferably causes a shortening (foreshortening) of the lattice structure 10. The transverse edges 25a, 25b of longitudinally adjacent cover elements 21, 22, 22 'can shift relative to one another and form overlapping regions 27 in the expanded state. In this way, a secure cover of the lattice structure 10 in the implanted or

guaranteed expanded state. Moreover, a secure cover 20 is thereby achieved, in particular in the cases when the medical implant is used in the region of vessel curvatures. On the peripheral side of the lattice structure 10, which is closer to the center of curvature of the vessel curvature, shortens the

Lattice structure 10, whereas the oppositely arranged peripheral side extends. Due to the overlapping of the cover elements 21, 22, 22 'in the longitudinal direction of the lattice structure, a closed cover 20 can be formed on both circumferential sides. Alternatively, the cover elements 21, 22, 22 'in the compressed state of the grid structure can be arranged in the longitudinal direction in such a way that a distance, in particular a transverse gap, between the cover elements 21, 22, 22' is established even in the compressed state. During the transition of the lattice structure 10 or in general the medical implant into the expanded state, the distance is reduced by the shortening of the lattice structure 10.

In general, two or more cover elements 21, 22 'may be arranged one above the other like a layer in sections. For example, in the

compressed state of the lattice structure 10, an overlap region 27 of a first cover member 21, which comprises 80% of the area of the first cover member 21, be arranged on a further, second cover member 22 and a

Overlap region 27 of the second covering element 22, which comprises 40% of the area of the further, second cover element 22, can be arranged on a further, third cover element 22 '. The first cover element 21 thus also overlaps the further, third cover element 22 'by 20%. Such

Multiple overlap is exemplified in FIG. Other

Overlap conditions, in particular in the expanded state of the lattice structure 10, are possible.

This mode of operation is readily discernible in FIGS. 2a and 2b, FIG. 2a showing the expanded state and FIG. 2b the compressed state of the medical implant. In the expanded state shown in FIG. 2a cursing the

Covering elements 21, 22, 22 'to each other. It can also be clearly seen in FIG. 2 a that the cover elements 21, 22, 22 'are arranged at regular intervals over the outer circumference of the lattice structure 10. In the expanded state form the

Cover elements 21, 22, 22 'each have a negative overlap region. This means that between the second longitudinal edges 23b and the first longitudinal edges 23a, which are each arranged adjacent to each other, a longitudinal gap 27th

is trained. The cover 21, 22, 22 'are thus arranged spaced from each other. It is also possible that the cover elements 21, 22, 22 'are arranged in abutment. Furthermore, the cover elements 21, 22, 22 'in the expanded state of the lattice structure 10 or in general of the medical implant

overlap. Fig. 2a shows the expanded or implanted state of

medical implant when positioning in a hollow organ or body vessel 30. The body vessel 30 may be, for example, a blood vessel. It should be noted that the implanted state of the lattice structure 10 or in general of the medical implant can deviate from the expanded state. In particular, the medical implant in the implanted state

preferably a slightly smaller cross-sectional diameter than in the expanded state. This ensures that a radial force is exerted on a vessel wall, so that the medical implant safely in the

Body vessel 30 is held. The difference between the implanted and expanded states is essentially negligibly small, and primarily concerns the dimensions, in particular the cross-sectional dimensions, of the medical implant. In the context of the application, the geometric shape of the medical implant in the expanded state essentially corresponds to the geometric shape in the implanted state, unless explicitly mentioned otherwise.

FIG. 2b shows the compressed state of the medical implant according to a preferred exemplary embodiment. It can be clearly seen that the cover elements 21, 22, 22 'overlap in the compressed state and each form an overlap region 24. Furthermore, Fig. 2b shows clearly that the

Medical device in the compressed state a relatively small

Has cross-sectional diameter. The crimping or compression of the

Lattice structure 10, unlike known implants with a cover 20, is not limited by the cover 20 folded between the webs 11. Rather, the overlapping of the cover elements 21, 22, 22 'allows compression of the medical implant such that further compression is limited by the webs 11. In the medical device, the compressibility or crimpability is determined by the webs 11, in particular the width of the webs 11. The medical device is placed in a compressed state, for example, in a catheter 32. In the compressed state, the medical indicates

Device further has a uniform outer structure, since the cover 21, 22, 22 'overlap uniformly over the outer periphery of the lattice structure 10. Thus, the frictional force between the medical implant and the inner wall of the catheter 32 is evenly distributed, which facilitates the handling of the medical implant.

The compressed state of the medical implant is also shown in FIG. 3

shown. In it is a section of the outer circumference of a medical

Implant, wherein the medical implant has a lattice structure 10, on which a cover 20 is arranged. The cover 20 comprises three cover elements 21, 22, 22 ', wherein a first cover element 21 in the compressed state of the lattice structure 10 overlaps a second cover element 22. The second cover element 22 in turn overlaps a third cover element 22 '. Between the first cover 21 and the second cover 22 and between the second cover 22 and the third cover 22 'is one each

Overlap area 24 is formed. The overlap region 24 has a length which is substantially half the width of a cover element 21, 22, 22 'in FIG

Circumferential direction of the grid structure corresponds.

As shown in FIGS. 1 and 3, the cover elements 21, 22, 22 'have pores 26. On the one hand, the pores 26 promote the endothelialization of the medical implant. On the other hand, the pores 26 counteract stresses that act on the cover 20 in the axial direction when the lattice structure 10 is compressed. The comparison between Figures 1 and 3 shows that the cells 15 are in the axial direction, i. in the longitudinal direction of the lattice structure, extend when the lattice structure 10 is converted from the expanded state to the compressed state. The pores 26 in the cover elements 21, 22, 22 'increase the flexibility of the cover elements 21, 22, 22', so that the cover elements 21, 22, 22 'of the

Length change of the cells 15 follow in the longitudinal direction.

The pores 26 preferably have a diamond-shaped geometry. The angle of the corners of the diamond-shaped pore lying opposite in the longitudinal direction of the lattice structure is preferably at least 90 °, in particular at least 120 °, in particular at least 150 °, in particular at least 160 °, in particular at least 170 °. It is also possible that the corner angle is almost 180 °. The pores 26 are formed as slots, which are in

Circumferential direction of the tubular lattice structure 10 extend. The gap width of the slots is preferably at most 300 μm, in particular at most 200 μm, in particular at most 100 μm, in particular at most 50 μm.

The pores 26 are arranged in a regular pattern and each form an opening area or pore size of at most 2 mm ² , in particular at most 1 mm ² , in particular at most 0.5 mm ² , in particular at most 0.3 mm ² ,

in particular at most 0, 1 mm ² , in particular 0.05 mm ² , in particular at most 0.01 mm ² , in particular at most 0.005 mm ² , in particular at the most 0.001 mm ² . A pore size of at least 0.01 mm ^2, in particular at least 0.05 mm ^2, in particular at least 0, 1 mm ^2, in particular at least 0.5 mm ^2, in particular at least 1 mm ^2, in particular at least 1.5 mm ² allows a efficient delivery of body fluids into a laterally branching body vessel. With pore sizes of at most 0.005 mm ² , in particular at most 0.001 mm ² , a particularly efficient coverage of the cells 15 can be achieved. For the promotion of a

Endothelialization, it is particularly advantageous if the pore size between 0.01 mm ² and 0.001 mm ² , in particular between 0.05 mm ² and 0.001 mm ² , in particular between 0.01 mm ² and 0.001 mm ² .

It is preferably provided that the lattice structure 10 is formed such that an axial change in length of the cells 15 is reduced. For this purpose, it is advantageously provided that the angle between two in a crossing point 12th

merged webs 11 of a single cell 15 is relatively small. This ensures that a shortening of the circumferential extent of the cell 15 leads to a relatively small change in the longitudinal extent of the cell 15. The angle between two webs 11 merged at a point of intersection 12 can also be

be comparatively large in order to achieve improved flexibility of the lattice structure 10.

FIG. 3 shows a partially compressed state of the medical implant. Further compression is possible, the overlapping area between the cover elements 21, 22, 22 'being increased. The overlapping area 24 between the first cover element 21 and the second cover element 22 may, for example, have a length that corresponds at most to the circumferential extent of the second cover element 22. The same applies to the overlapping region 24 between the second cover element 22 and the third cover element 22 ', as well as between further cover elements 21, 22, 22'.

The cover elements 21, 22, 22 'may have different circumferential extents and / or longitudinal extents. Overall, the cover 21, 22, 22 'can be different in size. A uniform design of the cover elements 21, 22, 22 'is preferred. In particular, it is advantageous if the

Covering elements 21, 22, 22 'regularly have the same geometry and the same size.

FIG. 4 shows the medical implant according to FIGS. 1 to 3 in an implanted state. The medical implant is in one Body vessel 30 is positioned, from which a secondary vessel 31 branches off. The cover 20, in particular the individual cover elements 21, 22, 22 'have a flexible material.

It is advantageously provided that the cover is a plastic, in particular

Polyurethane, includes. It is particularly preferred if the cover 20 or the cover elements 21, 22, 22 'have a nickel-titanium alloy, in particular nitinol. A combination of a plastic and a nickel-titanium alloy is possible. For example, corresponding composite materials can be used. Other possible materials include biodegradable materials, such as magnesium or magnesium alloys. The resolution of

Covers accelerate endothelialization when the acute function of the cover is no longer needed. The whole structure or just the

Cover or even the webs may be partially or completely biodegradable. It is also possible that drugs (gene therapeutics, anticoagulants or other substances) are incorporated within the biodegradable material, or on its surface, or in micro- or nanostructures in the material.

The wall thickness of the cover 20 and the cover 21, 22, 22 'is preferably at most 15 μιη, in particular at most 10 pm, in particular at most 8 pm, in particular at most 6 pm, in particular at most 4 pm, in particular at most 3 pm, in particular at most 2 pm ,

The flexibility or flexibility of the cover 20 or the cover elements 21, 22, 22 'is preferably adapted such that the cover element 21, 22, 22' by at least 20 °, in particular at least 30 °, in particular at least 45 °, in particular at least 60th °, in particular at least 90 °, is radially deflectable. In this case, the radial deflection refers to the circumference or a

Umfangstangente the tubular lattice structure 10. Furthermore, the radial

Deflection in the specified maximum values preferably in the elastic range. In the case of radial deflection, the cover element 21, 22, 22 'has a deflection radius which is at most 2 mm, in particular at most 1.5 mm, in particular at most 1 mm, in particular at most 0.8 mm, in particular at most 0.6 mm, in particular at most 0 , 4 mm, in particular at most 0.2 mm, in particular at most 0, 1 mm, in particular at most 0.05 mm. The maximum deflection radius refers to the most curved point during deflection. The radial deflection of the cover 21, 22, 22 'may be effected for example by a fluid flow, as indicated in Fig. 4 by arrows. Alternatively, the radial deflection of the cover 21, 22, 22 'by a mechanical force, for example, by advancing a catheter, in particular a coil catheter occur.

According to a further exemplary embodiment, which is illustrated in FIGS. 5a and 5b, a single first cover element 21 is provided, which completely surrounds the lattice structure 10. The cover 20 of the grid structure 10 is formed by a single cover member 21. The cover element 21 has a first longitudinal edge 23a, which is firmly connected to a web 11 of the lattice structure 10. The second

Longitudinal edge 23b is arranged freely or loosely on the lattice structure 10. in the

implanted state in a body vessel 30, as shown in Fig. 5a, the free, second longitudinal edge 23b overlaps the fixed first longitudinal edge 23a. This ensures that the lattice structure 10 is completely enveloped or covered. In other words, the cover 21 extends completely over the

It is possible that the second longitudinal edge 23b and the first longitudinal edge 23a in the expanded state, in which the

Grid structure 10 has a slightly larger cross-sectional diameter than in the implanted state, does not overlap. An overlapping arrangement is also preferred in the expanded state. This ensures that the second longitudinal edge 23b slides or moves over the cover element 21 during the transfer to the compressed state of the lattice structure 10. In this case, the second

Longitudinal edge 23b encircle or wrap around the outer circumference of the lattice structure 10 several times, so that in the compressed state, a multi-wrapped

Cover 20 forms, as shown in Fig. 5b.

The abovementioned exemplary embodiments have in common that the cover elements 21, 22, 22 'are strip-shaped, with the cover elements 21, 22, 22' extending in the longitudinal direction of the lattice structure 10 over a plurality of cells 15.

Preferably, the cover elements 21, 22, 22 'extend in the longitudinal direction of the lattice structure 10 over the entire length of the lattice structure 10. In the circumferential direction of the lattice structure 10, the cover elements 21, 22, 22' may form part of a cell 15 or an entire cell or cells spread. The hangs

Extension of the cover 21, 22, 22 'in the circumferential direction of the lattice structure 10 from the degree of compression or expansion. For example, that can

Cover element 21, 22, 22 'in the partially compressed state of the lattice structure 10 several cells overlap in the circumferential direction. In the expanded state, the number of circumferentially covered by the cover 21, 22, 22 'cells 15 may be smaller, for example, a cell. The coverage of the cells 15 in the longitudinal direction of the lattice structure is substantially independent of the expansion state of the lattice structure 10. This means that in the compressed state of

Lattice structure 10 by the cover 21, 22, 22 'substantially the same number of cells 15 is covered, as well as in the expanded state of

Grid structure 10.

In the embodiment of FIG. 6, however, is provided that the

Covering element 21, 22, 22 'substantially covers a single cell 15. For this purpose, the cover member 21, 22, 22 'is strip-shaped in the sense that the cover 21, 22, 22' has a longitudinal extent in the longitudinal direction of the lattice structure 10, which is significantly greater than the extent in the circumferential direction of the lattice structure 10. The longitudinal edges 23a , 23b of the cover element 21, 22, 22 'have a curved shape, the main orientation direction of the longitudinal edges 23a, 23b being aligned in the longitudinal direction of the lattice structure 10. The cover element

21, 22, 22 'furthermore has two transverse edges 25a, 25b, wherein the first transverse edge 25a essentially forms a tip aligned in the longitudinal direction of the lattice structure 10, which has a connection point 13. The connection point 13 is fixedly connected to a crossing point 12 of the lattice structure 10. The second transverse edge 25b has a rounded shape, wherein the main orientation direction of the second transverse edge 25b is aligned substantially in the circumferential direction of the lattice structure 10. The first transverse edge 25a and the first and second longitudinal edges 23a, 23b are arranged freely or loosely on the lattice structure 10. That means that

Covering element 21, 22, 22 'with the lattice structure 10, in particular with a

Junction point 12 of two webs 11, is selectively connected.

Fig. 6 shows the expanded or implanted state of the medical

Contraption. It can be seen that the cover elements 21, 22, 22 'in the

compressed state of the lattice structure 10 in both the longitudinal direction, as well as in the circumferential direction of the lattice structure 10 overlap. In this case, overlapping each other in the longitudinal or circumferential direction of the lattice structure 10 to each other arranged cover elements 21, 22, 22 '. In the expanded state, the cover elements 21,

22, 22 'a total of a cover 20, which consists of a pattern of individual

Covering elements 21, 22, 22 'is constructed. Free sections may be provided between the individual cover elements 21, 22, 22 '. Alternatively, it is also possible the cover elements 21, 22, 22 'are shaped such that the cover 20 completely cover the cells 15 of the lattice structure 10 when the lattice structure 10 assumes the expanded state.

In the embodiment according to FIG. 6, the additional function or the additional advantage of the invention becomes clear, according to which the cover elements 21, 22, 22 'can be deflected in the radial direction relative to the tubular lattice structure 10. Specifically, the cover 21, 22, 22 'may have a valve function. With regard to the valve function and other design features is the

Embodiment of FIG. 6 described in detail in the concurrently filed German patent application entitled "Medical Device", which is based on the applicant, wherein the features described therein and advantageous embodiments by reference fully in the present

Registration will be recorded.

In the figures 7a and 7b is an advantageous embodiment of

Manufacturing process for a medical device according to one of

shown above embodiments. In general, that can

Cover element or the first cover 21 and the other cover or the second cover 22 and the grid structure 10 are made separately. The cover elements 21, 22, 22 'can be produced for example by sputtering or etching. According to FIG. 7a, a flat lattice structure 10 and a cover 20 which is likewise spread over the surface and / or a covering element 21, 22, 22 'which has been laid out flat are provided. The cover 20 or the cover 21, 22, 22 'is connected to a first longitudinal edge 23a with the lattice structure 10 and a web 11 of the lattice structure. In particular, the first longitudinal edge 23a is connected to a first longitudinal end 16a of the lattice structure 10. The first longitudinal end 16a of the lattice structure 10 preferably has a plurality of webs 11, which are arranged adjacent to one another in the longitudinal direction of the lattice structure. The lattice structure 10 also has a second longitudinal end 16 b, the

preferably comprises a plurality of webs 11, which are arranged adjacent in the longitudinal direction of the lattice structure. The connection between the first longitudinal edge 23 a of the cover 20 and the first longitudinal end 16 a of the lattice structure 10 can

for example, by welding, in particular laser welding or

Resistance welding, done. Alternatively, the cover 21, 22, 22 'or generally the cover 20 with the grid structure 10 are connected by soldering or gluing. Another possibility is the cover 20, in particular the

Covering 21, 22, 22 'by a deposition method directly on the planar or surface spreading grid structure 10 applied. For this purpose, the lattice structure 10 is first provided with a sacrificial layer, which is structured such that a

Connection of the deposited covering layer directly with webs 11 of the lattice structure 10 is made possible. For example, the cover layer can only be connected at the edge to the webs 11 of the lattice structure 10. In the areas of

Lattice structure 10, which are provided with the sacrificial layer, the cover 20 is also deposited. This results from the in these areas

deposited portions of the cover layer, the loose, second longitudinal edges 23 b of the cover 21, 22, 22 '.

As shown in Fig. 7b, the first flat spread lattice structure 10 is converted into the tube shape. The first longitudinal end 16a of the lattice structure 10 is preferably welded to a second longitudinal end 16b. Alternatively, it may be provided that the lattice structure 10, in particular the individual webs of the lattice structure 10 and at the junction of the two longitudinal ends 16a, 16b by a

Crimped connection is connected by means of sleeves, wherein in each case a sleeve surrounds two webs 11 to be joined together and is crimped for fixing. The cover member 21, 22, 22 'is then rolled around the grid structure 10 as shown by the arrow in Fig. 7b. The cover 21, 22, 22 'is thus largely free or loose on the lattice structure 10. The connection between the cover 21, 22, 22 'and the grid structure 10 is only along the first longitudinal edge 23 a of the cover 21, 22, 22'. Overall, the cover 20 is thus selectively connected to the grid structure 10, wherein free or loose areas of the cover 20 are provided, which slide freely on the lattice structure 10. The

Cover 20 is preferably by welding to the web 11 and the

Junction 12 of the grid structure 10 connected.

It is also possible that the cover 21, 22, 22 'or generally the

Cover 20, in particular a film is applied by a sputtering process on the planar or flat spreading lattice structure 10. A similar

Manufacturing process is described for example in WO 2008/022799 AI. When applying the film or cover 20 to the lattice structure 10 by a sputtering process, it is expedient to provide at least one pre-processing step to ensure that the film or cover 20 at some Regions of the lattice structure 10 rests freely or loosely. For example, a sacrificial layer can be applied to the lattice structure 10 in the pre-processing step. The sacrificial layer may include, for example, a photoresist. The photoresist is exposed, the structure of the cover 21 and the structure of the

Connecting points 13 is impressed. In a further pretreatment step, the photoresist is etched, so that the structuring is reflected three-dimensionally in the photoresist. After these Vorbearbeitungsschritten sputtering of the cover 20 and the film takes place, wherein the film in the areas in which the photoresist was etched or structured, adheres. This means that the etched areas of the photoresist subsequently form the connection points 13. In a further step, the photoresist or the sacrificial layer is completely removed, for example by further etching. As an alternative to the photoresist, a sacrificial foil may also be provided. The

The sacrificial foil can be arranged on the lattice structure 10 and patterned by etching. Subsequently, analogously to the processing with the photoresist, the sputtering of the film or cover 20 and the subsequent removal of the sacrificial film. The film or cover 20 can then by another

Etching process are structured or perforated.

Another advantageous production method is shown in FIGS. 8a to 8c

shown. First, a lattice structure 10 is provided which is in a flat shape (FIG. 8a). The grid structure 10 has two free ends or two longitudinal ends 16a, 16b, which are arranged in abutment to form the tubular shape of the grid structure 10, as shown in Fig. 8b. In a further step, the separately produced film or cover 20, in particular the separately produced

Covering element 21, 22, 22 ', arranged in the region of the two abutting longitudinal ends 16a, 16b. According to FIG. 8b, the cover element 21, 22, 22 'is arranged centrally in the region of the two abutting longitudinal ends 16a, 16b. It is also possible for a longitudinal edge 23a, 23b of the cover element 21, 22, 22 'to be arranged in the region of the abutting longitudinal ends 16a, 16b. In a further step, the longitudinal ends 16a, 16b and at the same time

Cover member 21, 22, 22 'connected together. Through a connection,

For example, a weld, so both the tubular shape of the grid structure can be prepared, and the cover 20 are connected to the grid structure 10.

According to FIG. 8 b, a single cover element 21 is connected to the lattice structure 10. The cover element 21 is subsequently wound around the lattice structure 10 such that the cover element 21 completely encloses the lattice structure 10 wrapped when the lattice structure 10 assumes the expanded state. It is also possible that a plurality of cover elements 21, 22, 22 'over the circumference of

Distributed grid structure can be connected to the webs 11. It can

For example, the first cover 21 are connected analogously to the manufacturing method of FIG. 8b with the grid structure 10, wherein the first cover 21 is connected to the two longitudinal ends 16a, 16b of the grid structure 10. Further cover elements 22, 22 'can be connected to further webs 11 on the now present tubular lattice structure 10, as shown for example in FIG. 8c.

It is also possible for two cover elements 21, 22, 22 'to be arranged in the region of the abutting longitudinal ends 16a, 16b. Preferably, in this case, in each case the first longitudinal edges 23a in the region of the abutting longitudinal ends 16a, 16b of the lattice structure 10 are arranged in abutment and simultaneously welded to the longitudinal ends 16a, 16b. The first longitudinal edges 23a of the

Covering elements 21, 22 may also be arranged offset relative to one another on the abutting longitudinal ends 16a, 16b of the lattice structure 10 in such a way that the cover elements 21, 22 overlap. In the overlapping area of the

Covering 21, 22, the cover 21, 22 are arranged one above the other flat. In a single welding process are the one above the other

arranged covering elements 21, 22, in particular in the vicinity of their respective first longitudinal edges 23a, flat with each other and simultaneously with the abutting arranged longitudinal ends 16a, 16b of the lattice structure 10 welded.

Fig. 9a shows the medical implant made according to Fig. 8c. Other production methods, in particular others mentioned in the application

Manufacturing methods are possible. In Fig. 9a it can be seen that each one

Covering element 21, 22, 22 'is connected centrally to the lattice structure 10.

In particular, the cover element 21, 22, 22 'is connected in each case at an intersection point 12 of the lattice structure 10. In a crossing point 12 two webs 11 are coupled together, as shown in Fig. 9a. The cover element 21, 22, 22 'is in each case connected to a plurality of crossing points 12 of the lattice structure 10, which are arranged adjacent to one another in the longitudinal direction of the lattice structure 10. This results in the strip-shaped, elongated extension of the cover 21, 22, 22 '.

In Fig. 9b, the medical implant according to FIG. 9a in the crimped or

shown compressed state, it can be seen that the Cover elements 21, 22, 22 'in the circumferential direction of the lattice structure 10 overlap and thus arrange space-saving.

In another manufacturing method for covers that overlap with the grid structure, the cover may be made to extend only within an area within a cell. At this first

Manufacturing step, there is no overlap. By the subsequent deformation of the cell, for example by the compression of the cell in the circumferential direction, the overlap of the cover takes place with the lattice structure. In this state, the resting state of the cell is fixed again, for example by a heat treatment. The cell assumes its final geometry at rest. The grid structure, or the stent therefore has covers at rest, which overlap at the grid structure. This manufacturing technique is easy to implement and suitable for all geometries where the cover overlaps with the grid structure. Overlapping at rest prevents the foil or cover from bending into the cell during crimping.

In general, the medical implant has the expanded or

implanted state within a body vessel 30. The compressed

Condition is preferably taken within a catheter 32.

The invention is particularly suitable as a stent or vascular support or as

Vascular prosthesis. It is also possible that the tubular lattice structure 10 is closed at an axial end, so that the invention can be used as a thrombosis filter.

Preferably, the medical implant is used as a flow diverter. Flow diverters block the flow of fluid into an aneurysm so that embolization of the aneurysm can be beneficial. The particular advantages of the invention, namely the improved coverage of the lattice structure and the increased degree of coverage with simultaneously improved crimpability, come in the

Use as a flow diverter particularly advantageous for carrying. In particular, the high crimpability is useful for the treatment of aneurysms, since these are usually difficult to reach, i. very small, blood vessels are located. To supply a flow diverter, therefore, is a catheter with a very small size

Cross-sectional diameter appropriate. In addition to the use as a flow diverter, the invention can also be used as a stenotic stent. Due to the improved crimpability, the stenotic stent can be guided in relatively small blood vessels to a treatment site. The increased degree of coverage provides a particularly reliable protection against particle detachment.

For all embodiments and in general for the invention is that the cover 20 both extend completely over a cell 15, in particular completely cover the cell 15, can. In this case, the cover 20 completely covers the cell opening, that is to say the free space arranged between the webs 11. But it is also possible that the cover 20, the cell 15 partially covered, so that a portion of the space between the webs 11 remains uncovered or free. In both cases, the cover 20 projects beyond the contour of a web 11 and extends into the free space between the webs 11 of a cell 15 or completely covers it.

The cover 20 may generally have various shapes. For example, the cover 20 may be substantially rectangular in shape, as shown in Figure 1. Other shapes are possible, particularly when the cover 20 is associated with a respective cell 15, as shown by way of example in FIG. The cover 20 is designed substantially oval or drop-shaped. The cover 20 may also have an outer contour or generally a shape that corresponds to the shape of the cell 15, for example, in a partially expanded state.

In particular, the cover 20 may have a dragon-shaped or diamond-shaped or parallelogram-like outer contour, wherein at least two longitudinal edges 23a, 23b have a main orientation direction which extends in the longitudinal direction of the lattice structure 10, ie parallel to a longitudinal axis of the lattice structure 10. It is not excluded that the longitudinal edges 23a, 23b and a

Have peripheral component, so extend obliquely to the longitudinal axis of the lattice structure 10. However, it is essential that the main orientation direction in

Extensively extends, so an axial component of the longitudinal edge 23a, 23b predominates.

In connection with all embodiments and generally in

In connection with the invention, it is disclosed that the cover 20 is loosely arranged on the lattice structure 10 and connected locally with it, such that when there is a change in the diameter of the lattice structure a relative movement between the lattice structure

Cover 20 and the grid structure 10 takes place. The relative movement manifests itself in that the cover 20 moves relative to the cells or to the webs of the cells on which the cover 20 is arranged. The cover 20 and the grid structure 10 are thus arranged in two different planes and movable substantially within these planes relative to each other. In other words, the cover 20 and the grid structure 10 and the webs 11 of the grid structure 10 are arranged in different planes. The above arrangement is disclosed in the context of all cover elements 21, 22, 22 '. The connection between the lattice structure 10 or concretely between a web 11 of the lattice structure 10 and the cover 20 is formed such that a radially outer surface of the web 11 is connected to a radially inwardly disposed surface of the cover 20.

The ratio of the cover wall thickness and the web wall thickness is at most 50%, in particular at most 40%, in particular at most 30%, in particular at most 20%, in particular at most 10%, in particular at most 5%.

The lattice structure 10 is composed in a conventional manner of a plurality of cells which form segments in the circumferential direction. The segments are connected to each other in the longitudinal direction of the lattice structure and thus form the device or the implant as a whole. The cover 20 extends over these cells. This means that the support structure is formed by the lattice structure, which applies the radial force characteristic of the implant. The cover itself therefore has no load-bearing structure, but serves primarily to shield the lumen of the device. It is therefore a multi-layer, in particular a two-ply wall.

The cover 20 is designed in such a way that, during the radial compression of the device, it slides on the surface or lateral surface formed by the transverse structure 10, superposing further cells arranged on the circumference. When the cover 20 already has multiple cells superimposed in the expanded state, the superimposing degree increases so that additional cells are superimposed. In the preferred case, cell openings of the neighboring cells are superimposed or covered. The cover thus extends beyond the bridge or beyond the webs.

Examples Ia, Ib, 12a, 12b are explained with reference to FIGS

Main orientation of the covers can be arranged concretely. The Subsequent remarks will be related to all

Embodiments and generally disclosed in the context of the invention. In general, there are two possibilities as to how the main orientation of the covers 20 extends, namely once in the compressed state (FIG. 11a) and once in the expanded state (FIG. 12a). In the embodiment according to FIG. 11a, the axial components of the longitudinal edges 23a, 23b predominate radially

compressed state. The axial components are longer than the

Peripheral components of the longitudinal edges 23a, 23b. In the embodiment according to FIG. 11a, the shape of the cover 20 is designed so that the aforementioned orientation of the circumferential or axial components of the longitudinal edges 23a, 23b changes during the transition to the expanded state. This may, for example, as shown in Fig. IIb, be the case when the cover 20 is connected to a web IIa so that in a reorientation of the web I Ia in the course of expansion, the longitudinal edges 23a, 23b undergo a reorientation. In which

According to the exemplary embodiment according to FIGS. 11a, 11b, the first longitudinal edge 23a is connected to a section of the web 11a, which in the compressed state according to FIG. 11a, for example in the crimped state in the catheter, has a pronounced

Axial component has. The bridge is almost parallel to the longitudinal axis of the

Device or to the longitudinal axis of the catheter. The first and second longitudinal edges 23a, 23b of the cover 20 are substantially parallel to each other.

With an expansion of the device or the stent, the orientation of the web IIa changes, so that an angle between the web and the projection of the

Longitudinal axis of the device arises on the lateral surface, or an already

existing angle is increased. The main orientation of the longitudinal edges 23a, 23b in the longitudinal direction of the grid structure is maintained if the angle of the web remains less than 45 degrees. Also encompassed by the invention is the case where the angle of the web is at least 45 degrees in the expanded state (45 degrees or more). As a result, the webs 11a, 11b of the cells, especially in the case of a substantially diamond-shaped form of the cells, have a main orientation in the circumferential direction (peripheral component of the webs 11a, 11b is larger than the longitudinal component). In this case, the longitudinal edges 23a, 23b of the

Cover 20 has a main orientation in the circumferential direction of the device. This so-called main circumference orientation can be in the fully expanded state or in an intermediate state, for example in the implanted state in the vessel. Such embodiments of the device are encompassed by the invention. In the embodiment shown in Figs. 12a, 12b, the change in the main orientation direction of the longitudinal edges 23a, 23b is compared with that in Figs

Example according to Fig. IIa, I Ib in the reverse manner. As shown in Fig. 12a, the cover 20 is connected to one of the two longitudinal edges 23a, 23b different edge with the web I Ia. The main orientation direction of the two longitudinal edges 23a, 23b, that is to say the longer axial component in this case compared to the peripheral component of the two longitudinal edges 23a, 23b, extends in FIG

Longitudinal direction of the device. After the radial compression of the device, as shown in Fig. 12b, the main orientation of the cover 20 and the runs

Main orientation of the longitudinal edges 23a, 23b of the cover 20 in the circumferential direction. In both cases (Figure IIa, Figure 12a), the covers 20 are loose on the

Grid structure 11 is arranged and lead in the change in diameter of

Device from a relative movement to the radially inner cells of the grid structure 10 from. This is achieved in that the cover 20 is connected to a web I Ia, in particular with a single web I Ia. The two

Longitudinal edges 23a, 23b and the edge of the cover 20, which is arranged opposite the connected edge, are free. Thus, the cover 20

be moved together with the bridge I Ia. The freedom of movement of the individual cell is increased because the cover 20 can move together with the webs IIa.

Generally, the main orientation direction is determined by the longer component in the axial or circumferential direction.

Advantageously, a cover 20 or a cover element 21, 22, 22 'is mainly associated with a cell. This is especially true in the expanded state. In other words, at least one cover 20, at least in the idle state, is predominantly associated with a cell. This means that the surface portion of the cover 20, which covers the cell or the cell opening, is greater than that

Surface portion of the cover 20, which extends beyond the cell, specifically on the cell limiting webs I Ia, I Ib. This means that the cover 20 or a cover element 21, 22, 22 'in the expanded state covers only a single cell in terms of area completely or partially, or alternatively in the expanded state, a cell substantially completely and at least one further cell at least partially covered. This means that the cover is up to the

and extends beyond, so that the cover extends partially into the adjacent next cell. This type of extension may be transferred to two, three, four, five, six, or more than six substantially completely blanked cells and an adjacent partially blanketed cell. The completely covered cell can either be substantially completely covered in terms of area or completely cover or span the cell in terms of length. In the latter case, there is no complete coverage of the cell surface, ie in the

Substantially the area of the cell opening required to completely cover the cell. This concept can be applied to 2, 3, 4 or more than 4 cells, so that the cover 20 or the cover element 21, 22, 22 'in the expanded state covers at least two cells essentially completely and at least one further cell at least partially.

LIST OF REFERENCE NUMBERS

10 grid structure

11 footbridge

I Ia first footbridge

I Ib second bridge

12 crossing point

13 connection point

15 cell

16a, 16b longitudinal end

20 cover

21 First cover element

22 Second cover element

22 'third cover

23a first longitudinal edge

23b second longitudinal edge

24 overlap area

25a first transverse edge

25b second transverse edge

26 pores

27 longitudinal gap

30 body vessel

31 secondary vessel

32 catheters

Claims

claims

1. A medical implant having a tubular lattice structure (10) which can be converted into a radially compressed state and a radially expanded state, the lattice structure (10) having webs (11) and a cover element (21) arranged on the webs (11), at least partially extending over an outer periphery of the grid structure (10),

d a d u rc h e ke n ze i c h n et that

the cover element (21) is substantially strip-shaped and comprises a first and a second longitudinal edge (23a, 23b), which in

Circumferentially arranged circumferential direction of the grid structure (10) and each have a along the longitudinal direction of the grid structure (10) extending Hauptorientierungsrichtung, wherein the cover (21) with at least one web (11, IIa) of the grid structure (10) is firmly connected and the first and / or second longitudinal edge (23a, 23b) of the cover (21) loosely on the lattice structure (10) is arranged such that the first and / or second longitudinal edge (23a, 23b) in the transition of the lattice structure (10) in the radially expanded Circumferential state on the outer periphery of the grid structure (10) slides.

2. Medical implant according to claim 1,

d a d u rc h eke n ze i c h n et that

the first longitudinal edge (23a) of the cover (21) is fixedly connected to the web (11, IIa).

3. Medical implant according to claim 1 or 2,

d a d u rc h e n c e s n e s n e s that

at least one further cover element (22) is provided, which in

Circumferentially disposed circumferentially of the grid structure (10) to the cover member (21) and formed substantially strip-shaped and a first and a second longitudinal edge (23a, 23b) which are arranged circumferentially of the grid structure (10) spaced and one along the longitudinal direction the lattice structure (10) extending main orientation direction, wherein the further cover (22) with at least one further web (11, IIb) of the grid structure (10) is firmly connected and the first and / or second longitudinal edge (23a, 23b) of the further cover (22) is arranged loosely on the lattice structure (10) such that the first and / or second longitudinal edge (23a, 23b) during the transition of the lattice structure (10) in the radially expanded state in the circumferential direction on the outer periphery of the lattice structure (10) slides.

4. Medical implant according to claim 3,

d a d u rch e n ds i n s that

the first longitudinal edge (23a) of the further cover element (22) is fixedly connected to the further web (11, IIb).

5. Medical implant according to claim 3 or 4,

there is no such thing as that

the cover element (21) in the radially compressed state of the lattice structure (10) overlaps the further cover element (22) in the circumferential direction.

6. Medical implant according to at least one of claims 3 to 5,

d a d u rch e ke n ze i ch n et that

the second longitudinal edge (23b) of the cover element (21) in the radially compressed state of the lattice structure (10) overlaps the first longitudinal edge (23a) of the further cover element (22) in the circumferential direction of the lattice structure (10).

7. Medical implant according to at least one of claims 3 to 6,

d a d u rc h e s n e s n e s n e ch n eti ch n et that ch

the cover element (21) in the radially expanded state of the lattice structure (10) overlaps the further cover element (22).

8. Medical implant according to at least one of claims 3 to 7,

d a d u rc h e ke n ze ze ch n et that

the cover element (21) with the further cover element (22) a

Overlap region (24) forms, which is smaller in the radially expanded state of the lattice structure (10) than in the radially compressed state.

9. Medical implant according to claim 8,

d a d u rc h e e n c e s n e s that

in the compressed state of the lattice structure (10), the overlapping region (24) 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 50%, in particular at least 60%, in particular at least 70%, in particular at least 80%, in particular at least 90%, of the width of the further cover element (22) in the circumferential direction covers.

10. Medical implant according to at least one of claims 3 to 8,

d a d u rch g e n s zei c h n et that

the cover element (21) in the radially expanded state of the grid structure (10) is aligned with the further cover element (22) in the circumferential direction.

11. A medical implant according to at least one of claims 3 to 10,

d a d u rch e ke n ze i c h n et that

the second longitudinal edge (23b) of the cover element (21) in the expanded state of the lattice structure (10) from the first longitudinal edge (21a) of the other

Cover member (22) is arranged spaced and forms a longitudinal gap (27) having in the circumferential direction of the grid structure (10) has a width which is at least 0.1 times, in particular at least 0.2 times,

in particular at least 0.3 times, in particular at least 0.4 times, in particular at least 0.5 times, in particular at least 0.8 times, in particular at least 1 times, the width of the further covering element (22 ) corresponds in the circumferential direction.

12. A medical implant according to at least one of claims 1 to 11,

d a d u rc h e ke n ze i c h n et that

the cover element (21) and / or the further cover element (22) has at least one transverse edge (25a, 25b) loosely arranged on the outer periphery of the lattice structure (10) such that the transverse edge (25a, 25b) at the transition of the lattice structure (10) in the radially expanded state in

Longitudinal direction on the outer circumference of the grid structure (10) slides.

13. A medical implant according to at least one of claims 1 to 12,

d a d u rc h e ke n ze ze ch n et that

the cover element (21) and / or the further cover element (22) is connected at points to the grid structure (10), in particular the web (11, IIa) and / or the further web (11, IIb).

14. A medical implant according to at least one of claims 1 to 13,

dadu rc hge ke nn ze ichn et that the cover element (21) and / or the further cover element (22) is connected to at least two webs (11) arranged adjacently in the longitudinal direction of the lattice structure (10).

15. A medical implant according to at least one of claims 1 to 14,

d a d u rc h e n d i n s i n s that

the cover element (21) and / or the further cover element (22) is connected in the region of an intersection point (12) of the lattice structure (10) in which at least two webs (11) are connected to one another.

16. A medical implant according to at least one of claims 1 to 15,

d a d u rc h e n c e s n e s that

the cover element (21) and / or the further cover element (22) is flexible.

17. A medical implant according to at least one of claims 1 to 16,

d a d u rch g e n i c h n et that

the cover element (21) and / or the further cover element (22) has a structuring, in particular pores (26) or a perforation.

18. A medical implant according to at least one of claims 1 to 17,

d a d u rch g e n i c h n et that

the cover element (21) and / or the further cover element (22) is welded or glued or integrally formed with the web (11, IIa) and / or further web (11, IIb) of the lattice structure (10).

19. A medical implant according to at least one of claims 1 to 18,

d a d e d e r c e n ts i c h n et that

the cover element (21) with the at least one further cover element (22) is distributed uniformly over the outer circumference of the lattice structure (10).

20. A medical implant according to at least one of claims 1 to 19,

d a d u rc h e e n n e s n e s that

the cover element (21), individually or together with the at least one further cover element (22), completely covers the outer circumference of the lattice structure (10).

21. The medical implant according to claim 1, wherein:

the width of the cover element (21) and / or the further cover element (22) in the expanded state of the lattice structure (10) at least 1 times, in particular at least 1, 1-fold, in particular at least 1.2 times, in particular at least 1.3 times, in particular at least 1.4 times, in particular at least 1.5 times the value of the circumference, and / or in the compressed state at least 3 times, in particular at least 4 times, in particular at least 5 times,

in particular at least 6 times, in particular at least 7 times, in particular at least 8 times, in particular at least 9 times, in particular at least 10 times, in particular at least 12 times, in particular at least 14 times, in particular at least 16 times, in particular at least 18 times, in particular at least 20 times the value of the circumference of the lattice structure (10).

22. A medical implant according to at least one of claims 1 to 21,

d a d u r c h e c e n c i n e s that

a plurality, in particular at least two, further cover elements (22, 22 ') are provided, which are arranged in the circumferential direction of the grid structure (10) adjacent and in the radially compressed state of the grid structure (10) overlapping.

23. A method for producing a medical implant according to claim 1

comprising the following steps:

Providing a raw form of the grid structure (10);

Applying a sacrificial layer comprising a photoresist and / or a

Sacrificial foil on the lattice structure (10);

Structuring the sacrificial layer, using a structure of

Connecting points (13) of the grid structure (10) is exposed;

Applying a cover layer on the sacrificial layer and the

Connecting points (13) such that the cover layer to the

Removing the sacrificial layer to form a free longitudinal edge (23b) of the cover member (21). A method of manufacturing a medical implant according to claim 1, comprising the following steps:

Providing a planar lattice structure (10);

Providing a cover member (21);

Forming the lattice structure (10) into a tubular shape, wherein two

Longitudinal ends (16a, 16b) of the grid structure (10) in the circumferential direction

Shock be arranged;

Arranging the cover member (21) on the abutting longitudinal ends (16a, 16b); and

Connecting the two longitudinal ends (16a, 16b) of the grid structure (10) to each other and simultaneously the two longitudinal ends (16a, 16b) of the grid structure (10) with the cover element (21).