EP3930637A1

EP3930637A1 - Medical device, in particular a flow diverter, and kit

Info

Publication number: EP3930637A1
Application number: EP20706226.6A
Authority: EP
Inventors: Dr. Giorgio CATTANEO; Dr. Andreas SCHÜSSLER
Original assignee: Acandis GmbH and Co KG
Current assignee: Acandis GmbH and Co KG
Priority date: 2019-02-26
Filing date: 2020-02-19
Publication date: 2022-01-05
Also published as: DE102019104828A1; CN113613602A; DE102019104828B4; US20220047373A1; DE202020006038U1; WO2020173765A1

Abstract

The invention relates to a medical device, in particular a flow diverter, having a radially self-expandable lattice structure (10) which is tubular at least in some regions and which is composed of a plurality of interwoven individual wires (11) that form meshes (12) of the lattice structure (10), wherein at least some of the individual wires (11) have an X-ray-visible core material (11a) and a superelastic mantle material (11b), wherein a plurality of meshes (12) directly adjacent in the circumferential direction of the lattice structure (10) form a mesh ring (13), wherein the lattice structure (10), in a fully self-expanded state, has an expansion diameter Dexp, the mesh ring (13) has a mesh number n, and the core material (11a) has a core diameter dKern, and wherein, for the core diameter dKern, the following holds: dKern = f ∙ (Dexp/n), wherein the following holds for a visibility factor f: 0.08 ≤ f ≤ 0.15.

Description

Medical device, especially flow diverter, and set

description

The invention relates to a medical device, in particular a flow diverter or flow divider, according to the preamble of patent claim 1. Such a medical device is known, for example, from EP 2 247 268 B1.

The known medical device has a radially expandable lattice structure that is tubular in sections. The lattice structure is formed from a single wire that is intertwined with itself, creating meshes. The wire of the lattice structure is made from a composite material and comprises in particular a radiopaque core material and a superelastic sheath material.

The known medical device is designed as a stent. The

X-ray-visible core material of the known stent is intended to enable the stent to be seen under X-ray control. The super-elastic properties of the sheath material of the wire, on the other hand, should cause the stent to expand automatically, i.e. is self-expanding.

Stents for the endovascular treatment of intracranial aneurysms direct the blood flow away from the diseased vascular area. Such stents are called "Endoluminal Embolization Devices" or "Flow Diverters" are called and have a dense mesh system. By reconstructing the original vessel wall and changing the hemodynamic conditions in the aneurysm, flow diverters lead to its closure in the long term. Flow diverters are particularly suitable for the therapy of complex aneurysms, such as broad-based, fusiform or giant aneurysms, which often cannot be treated with other methods.

As part of a further development of the known stent, it has been shown that it is difficult to achieve high X-ray visibility of the lattice structure on the one hand and good self-expansion capability on the other hand, especially if the lattice structure is to be suitable for feeding into small, for example intracranial, blood vessels. When feeding into small blood vessels it is necessary that the lattice structure is very small

Cross-sectional diameter is compressed. However, this is made more difficult by a high proportion of X-ray visible material, since such a material usually tends to deform plastically. When the lattice structure expands in the blood vessel, the lattice structure can therefore not rest properly on the vessel wall. Superelastic materials, on the other hand, have a high compressibility and ensure good vessel adaptation of the lattice structure during expansion.

For good visibility it would be useful to increase the proportion of the X-ray visible core material of the wire. This makes it possible to achieve a visibility of the entire lattice structure, which is expedient in order to be able to check that the lattice structure rests securely on a vessel wall over its entire length. Radiopaque core materials, however, do not have any superelastic properties and therefore contribute to the expansion force required for the

Self-expansion of the lattice structure is useful, hardly at.

In particular, when such medical devices are fed into small blood vessels, preferably in the neurovascular area, a

Self-expansion capability, however, is desirable in order to be able to do without a balloon catheter to expand the lattice structure. Such a balloon catheter would limit the compression of the lattice structure so that the lattice structure cannot be introduced into particularly small blood vessels. A

Miniaturization of the lattice structure, especially in its compressed state is therefore desirable. Post-manipulation with a balloon catheter also increases the risk of injury.

Another factor that limits the compressibility of the lattice structure is the wire diameter. This should not be too big, because the

Otherwise, the wires will lie against each other early and prevent further compression of the lattice structure.

Overall, it is therefore useful to provide a lattice structure whose wire has the smallest possible cross-sectional diameter, but at the same time the ratio between the thickness of the cladding material and the core material is set so that, on the one hand, good X-ray visibility and, on the other hand, good self-expansion capability is achieved. These properties are dependent on the geometry of the lattice structure, in particular the diameter of the lattice structure in the fully expanded state and the number of

Mesh that the lattice structure has distributed over its circumference. This conflict of goals is exacerbated by the fine mesh of flow diverters, since the relatively thin wires have a relatively low radial force, so that the visibility or the platinum content of such braids is particularly critical.

Against this background, it is the object of the present invention to provide a medical device, in particular a stent, which has a high level of X-ray visibility and, at the same time, good self-expansion properties, the medical device being well connected via small catheters

especially micro-catheters, can be guided to the treatment site.

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

The invention is based in particular on the idea of a medical

Device, in particular a flow diverter, with at least one

Sectionally tubular, radially self-expanding lattice structure made from several interwoven individual wires that form the mesh of the lattice structure. At least some of the individual wires have a radiopaque core material and a superelastic sheath material. Several meshes directly adjacent in the circumferential direction of the lattice structure form a mesh ring, with the lattice structure in a fully self-expanded state

Expansion diameter D _exp , the mesh ring have a mesh number n and the core material have a core diameter d _K e _rn . According to the invention applies to the core diameter d _K e _rn: dKern- f (Dexp / fl)

It is provided according to the invention that for a visibility factor f:

0.08 <f <0.15

It has surprisingly been shown that within the scope of the visibility factor described above, there is a ratio between the core diameter of the

Sets the core material and the expansion diameter of the lattice structure, which means that the lattice structure is particularly well visible under X-ray control, at the same time has a sufficiently high radial force to meet the desired self-expansion properties well and also a

Total wire diameter of the wire can be maintained, which enables a particularly good compression of the lattice structure in small catheters, in particular micro-catheters. For example, the invention or the

Device according to the invention can be used with catheters of size 2 Fr, 2.5 Fr and 3 Fr or more.

The direct relationship between the core diameter and the

Expansion diameter taking into account the invention

set visibility factor allows you to get the right amount of

X-ray visible core material to choose for different medical devices, which differ from each other by the expansion diameter of their lattice structure. In other words, it's because of the

inventively provided relationship between the

Core wire diameter and the expansion diameter possible, the

to choose the best possible proportion of core material for different expansion diameters of lattice structures.

In general, the invention provides that the lattice structure

is self-expanding. The wire forming the lattice structure thus has

preferably superelastic properties. The lattice structure can automatically assume a completely self-expanded state in which no external forces act on the lattice structure. The inner ones

Rather, self-expansion forces of the lattice structure lead to the lattice structure reaching a maximum cross-sectional diameter, the

Expansion diameter, expands. This expansion diameter usually does not correspond to the cross-sectional diameter that the lattice structure assumes in the implanted state. It is common for one to be implanted

to select a medical device whose cross-sectional diameter is between 5% and 20%, in particular approximately 10%, above the cross-sectional diameter of a blood vessel into which the medical device is to be inserted. This oversizing ensures that the lattice structure in

implanted state exerts a sufficient radial force on the vessel walls so that the lattice structure remains firmly anchored to the implantation site.

There is also a risk of a change in the porosity of a

Overdimensioning of the stent or flow diverter.

Under the influence of external forces, the lattice structure can be converted into a compressed state. The maximally compressed state is reached when the lattice structure can practically no longer be compressed. This usually occurs when the wire sections, which are arranged next to one another in a distributed manner over the circumference of the lattice structure, approach one another to such an extent that the wire sections touch one another and thus prevent one another from further deformation. In other words, the completely compressed state is achieved in particular when the lattice structure is radially so far

is compressed so that the meshes of the lattice structure are hardly recognizable as such, since the wire sections are in direct contact with one another.

In the completely compressed state of the lattice structure, the lattice structure preferably has a cross-sectional diameter that is equal to or slightly smaller than an inner diameter of a catheter that is used to feed the medical device into a blood vessel. In other words, the feed diameter of the lattice structure is usually somewhat larger than the diameter of the lattice structure in the fully compressed state. With an expansion diameter D _exp of 2.0 mm <D _exp <3.5 mm, in particular 2.5 mm <Dexp <3.5 mm, the catheter has an internal diameter of 2 Fr to 2.5 Fr, in particular 2 Fr, in particular 2.5 Fr. With an expansion diameter D _exp of 3.5 mm <D _exp <5 mm, the catheter has an inside diameter of 2.5 Fr to 3 Fr, in particular 2.5 Fr and in particular 3 Fr. At a

The catheter has an expansion diameter D _exp of 5 mm <D _exp

Inside diameter from 3 Fr to 4 Fr, in particular 3 Fr, in particular 4 Fr.

A catheter size of 2 French (= 2 Fr) corresponds to one

Catheter inside diameter of approx. 0.4 mm. 2.5 French (= 2.5 Fr) correspond to an internal catheter diameter of approx. 0.52 mm. 3 French (= 3 Fr)

correspond to an inside diameter of the catheter of approx. 0.7 mm.

In general, the invention preferably provides that the

The expansion diameter of the lattice structure is between 2.5 mm and 8 mm. Medical devices that have lattice structures of this size are particularly suitable for treating diseases in neurovascular blood vessels. In particular, those are medical

Devices which are preferably designed as implants, in particular as stents in the form of flow diverters, are suitable for the treatment of diseases in intracranial blood vessels. Above all, it allows

intracranial aneurysms, stenoses or dissections and others

Treat vascular malformations well.

In a preferred embodiment of the invention it is provided that a width ratio RGS between the expansion diameter DE _XP and the

Number of meshes n with an expansion diameter DE _XP between 2.5 mm and

3.5 mm, between 0.10 mm and 0.22 mm, in particular between 0.15 mm and 0.20 mm. With an expansion diameter DE _XP between 3.5 mm and 6 mm, the width ratio RGS between the expansion diameter DE _XP and the number of meshes n is preferably between 0.15 mm and 0.25 mm, in particular 0.18 mm and 0.22 mm, preferably approx. 0.2 mm. At a

The expansion diameter DE _{XP is} between 6 mm and 7 mm

Width ratio RGS between 0.2 mm and 0.30 mm, in particular between 0.22 mm and 0.25 mm.

The width ratio RGS has a direct influence on the width of a mesh in the circumferential direction of the lattice structure. A high ratio between that

The expansion diameter and the number of meshes lead to a large width of the individual meshes. This has a disadvantageous effect on the stability of the lattice structure. In addition, a large mesh width can mean that in An aneurysm introduced coils, which are to be held back by the lattice structure, easily pass through the mesh. The RGS width ratio influences the reduction of the flow velocity within the aneurysm, the redirection of the blood flow into the main lumen and the fine-pored structure for vascular reconstruction.

Too small a ratio between the expansion diameter and the

The number of meshes leads to a small mesh width, which makes it difficult to feed the lattice structure through a catheter and the blood flow in side branches can be disturbed.

Surprisingly, it has been shown that the above-mentioned values for the ratio between the expansion diameter and the number of meshes offer a good compromise, so that the lattice structures designed in this way achieve a sufficiently high stability on the one hand and good feedability through a catheter on the other. In addition, a good flow effect is achieved. The medical devices designed in this way are therefore well suited to being anchored in a stable manner in a vessel and thereby improving the flow effect and at the same time allowing them to be easily guided to the treatment site through tortuous blood vessels.

In preferred embodiments of the invention it is also provided that a braiding angle α of the lattice structure is between 70 ° and 80 °, in particular approximately 75 °. The braiding angle influences the mechanical expansion behavior of the lattice structure and the porosity. In addition, the braid angle has an influence on the bending flexibility and the ability to feed the medical device through catheters. For the treatment of intracranial vessels, a braid angle between 70 ° and 80 °, in particular approx. 75 °, has been shown to be particularly preferred.

In the context of the present application, the angle that is spanned between the wire of a mesh and the longitudinal axis of the lattice structure is referred to as the braid angle. Specifically, to determine the braiding angle, the longitudinal axis of the lattice structure is projected into the circumferential plane of the lattice structure and then the angle is projected in a helical manner over the lateral surface of the

Lattice structure running wire determined. The braid angle is from

To distinguish the mesh angle between two intersecting Wire sections is stretched. In the context of the present application, the mesh angle corresponds in each case to double the braiding angle.

In order to achieve good compressibility, it has been found to be particularly advantageous if the wire has a wire diameter dü _r a _ht which, with an expansion diameter D _exp between 2.5 mm and 4.5 mm, ie 2.5 mm <D _exp <4.5 mm: 30 pm <dü _r a _ht <46 pm, and with an expansion diameter D _exp between more than 4.5 mm and 8 mm, ie 4.5 mm <D _exp <8 mm: 46 pm < dü _r a _ht <65 pm.

In connection with the number of meshes over the circumference of the

Lattice structure with a predetermined expansion diameter and a predetermined braiding angle of the lattice structure, the wire diameter also determines the ratio between the proportion of wire on the circumferential surface of the lattice structure in relation to the proportion of openings. This ratio between the proportion of wire material on the circumferential surface of the lattice structure and the total surface area of the lattice structure is referred to as the mesh density.

The ratio between the area of the openings, i.e. the mesh area, and the total stent jacket area is referred to as porosity. On the

The wire diameter has the mesh density or porosity of the mesh

immediate influence. The wire diameter also influences the

Radial force of the lattice structure and its ability to be fed through small catheters.

It has been shown that the specified wire diameters are particularly advantageous for the expansion diameters specified above, that is to say, on the one hand, a sufficiently high radial force and, on the other hand, a good one

Provide deliverability through catheters. In addition, these

Wire diameters achieved a particularly advantageous mesh density or porosity for the treatment of intracranial blood vessels.

The braiding angle also has an influence on the porosity of the lattice structure. With the above-mentioned preferred values for a braid angle in combination With the aforementioned wire diameter values, a particularly advantageous porosity is achieved.

In order to ensure that the lattice structure of the medical device according to the invention has good self-expansion capabilities, it is advantageously provided that the sheath material of the wire has a thickness that is at least 10 μm, in particular at least 15 μm, in particular from 10 μm to 20 μm. It has been shown that regardless of the expansion diameter of the lattice structure, a particular minimum thickness is required for the jacket material

to achieve sufficiently good self-expansion properties.

A minimum value of 10 μm as the thickness of the jacket material has proven to be particularly advantageous in order to achieve the desired self-expansion properties. The jacket material not only enables an improvement in the

Self-expansion properties of the lattice structure, but also forms a good corrosion protection and protects against abrasion due to its special hardness.

For wires that are thicker overall, a higher minimum thickness of the

Sheath material be provided. For example, wires with a

Total thickness of at least 50 μm, in particular at least 60 μm

Have jacket material with a thickness of at least 15 μm. In order to also achieve good visibility properties of the lattice structure, it is advantageously provided that the volume of the core material takes up a percentage of the total volume of the wire.

The volume of the core material preferably takes up a percentage of the total volume of the wire, with a visibility factor f of 0.08 to 0.15 the percentage of the total volume being from 13% to 45%, in particular from 15% to 40%.

With a visibility factor f of 0.08, the percentage of the total volume is preferably from 15% to 25%, in particular from 18% to 22%. With a visibility factor f of 0.1, the percentage of the total volume is preferably from 15% to 30%, in particular from 20% to 25%. With a visibility factor f of 0.12, the percentage of the total volume is preferably from 20% to 35%, in particular from 25% to 30%. With a visibility factor f of 0.15, the percentage of the total volume is preferably from 25% to 45%, in particular from 30% to 40%.

The visibility factor f of 0.12 or 0.15 is suitable for larger dimensions from an expansion diameter of 3.5 mm. The visibility factor f of 0.08 is suitable for smaller dimensions with an expansion diameter between 2.5 and 3.5 mm.

The lattice structure preferably has closed loops at one axial longitudinal end and open wires with free ends at the other axial longitudinal end. In addition, there are between 1 and 4 loops of double wires that have the same diameter or different diameters than the other individual wires of the lattice structure, i.e. as the "standard wires". In this case, the platinum content can also be different.

For good X-ray visibility of the medical device, it has proven to be particularly advantageous if the core material of the wire consists of platinum or a platinum alloy. Alternatively, the core material can consist of tantalum or a tantalum alloy. Further suitable materials are gold, silver, tungsten and / or niobium and alloys thereof.

The jacket material is preferably made of a nickel titanium alloy, in particular nitinol. In a particularly preferred variant, the nickel-titanium alloy can have a nickel content of 50.8 atomic percent.

The surface of the cladding material can comprise an oxide layer.

In particular, an oxide layer with a layer thickness between 50 nm and 500 nm, in particular between 100 nm and 400 nm, in particular between 200 nm and 350 nm, can be provided. The oxide layer allows the

Wire sections can slide well on each other and thus promotes the

Self-expansion properties of the lattice structure.

In one embodiment, the following applies to the visibility factor f:

0.08 <f <0.14, in particular 0.08 <f <0.13, in particular 0.08 <f <0.12, in particular 0.08 <f <0.11, in particular f = approx. 0, 1. The proportion of the individual wires with the X-ray visible core material and the superelastic jacket material in the total number of individual wires is preferably at least 50%, in particular at least 75%, in particular 100%. At 100%, all individual wires are each radiopaque

Core material and super elastic jacket material made.

The number of meshes in a mesh ring is preferably n in one

Expansion diameter D _exp from 2.5 mm to 4.5 mm, ie 2.5 mm <D _exp <4.5 mm: 12 <n <24, in particular 16 <n <24. With an expansion diameter D _exp of more than 4 , 5 mm to 8 mm, ie 4.5 mm <D _exp <8 mm, the number of meshes n of a mesh ring is 24 <n <36, in particular 24 <n <32.

One aspect of the invention provides for a set with an above-described medical device and a catheter, wherein the

medical device in a compressed state can be arranged longitudinally displaceably in the catheter. The set can also comprise a transport wire, the medical device being connectable or connected, in particular releasably connected, to the transport wire. The catheter contained in the set preferably has an inner diameter which is at most 0.7 mm, in particular at most 0.6 mm, in particular at most 0.5 mm, in particular at most 0.4 mm.

The invention is explained in more detail below using an exemplary embodiment with reference to the attached schematic drawings. Show in it:

1: a schematic side view of a medical device, in particular a flow diverter according to a

embodiment of the invention;

FIG. 2: a schematic representation of a mesh of the lattice structure of the medical device according to FIG. 1; and

3: a schematic representation of a cross-sectional profile of a

Single wire of the medical device according to FIG. 1. In the embodiment shown in the figures a

The medical device according to the invention is a flow diverter which is suitable for treatment in intracranial blood vessels.

In principle, the medical device can be designed as a medical instrument or as a medical implant. In all cases it is preferably provided that the medical device is through a catheter

minimally invasive to a treatment location, especially within one

Blood vessel, can be performed.

Medical implants, on the other hand, remain essentially permanently at their treatment site. Such implants are flow diverters that are used to treat aneurysms in blood vessels.

The flow diverter shown in the accompanying drawings is preferably suitable for the treatment of aneurysms in intracranial blood vessels. The flow diverter has a tubular, radially expandable lattice structure 10 made of a plurality of interwoven individual wires 11 which form meshes 12 of the lattice structure 10.

The lattice structure 10 is highly compressible and can thus be guided to the treatment site through small catheters. The lattice structure 10 has a high degree of bending flexibility, so that feeding and anchoring in heavily twisted blood vessels are easily possible.

As can be clearly seen in FIG. 1, the lattice structure 10 has several meshes 12 which, viewed in the circumferential direction of the lattice structure 10, each form mesh rings 13. A mesh ring 13 is formed from a plurality of meshes 12 which are directly adjacent to one another in the circumferential direction of the lattice structure

are arranged. The individual meshes are separated from one another by crossovers 18 of the individual wires 11.

The lattice structure 10 is made up of a plurality of mesh rings 13 arranged directly adjacent in the longitudinal direction of the lattice structure 10. It is preferred if each machine ring 13 has an even number of meshes 12. The mesh ring 13 can in particular have 12, 14, 16, 32 or more meshes. The lattice structure 10 is self-expanding and automatically expands radially without the action of external forces. In this unloaded state, the lattice structure 10 assumes the expansion diameter D _exp . In a fully expanded state, the lattice structure 10 consequently has the

Expansion _diameter D _exp .

In contrast, an external force is required to the

To transfer lattice structure 10 into a compressed state. A state in which the lattice structure 10 assumes its smallest possible diameter is the completely compressed state. In this completely compressed state, the lattice structure 10 has a compression _diameter D _k0 m _P. When the lattice structure 10 is compressed, the width of a mesh 12 is reduced in the circumferential direction of the lattice structure 10. This reduction in width takes place until the wire sections which delimit the mesh 12 lie against one another. The wire 11 thus blocks further compression of the

Lattice structure 10. For mechanical or geometrical reasons, the lattice structure 10 cannot be compressed to any desired extent, but has a minimal diameter, from which further compression is no longer possible. This state forms the completely compressed state in which the lattice structure 10 has a compression _diameter D _k o _mP .

A compression _diameter D _k o _{mP which} is as small as possible is expedient in order to be able to guide the lattice structure 10 through the smallest possible catheter to the treatment site. In particular, it is provided that the lattice structure is compressible or can _assume such a compression _diameter D _k o _mP that the lattice structure reaches the treatment site via a catheter with an inner diameter of at most 3 French, in particular 2.5 French, in particular at most 2 French can be performed. Specifically, the

_{Lattice structure assume} a compression _diameter D _k o _mP which is at most 0.7 mm, in particular 0.6 mm, in particular at most 0.51 mm, in particular at most 0.42 mm.

At least one single wire 11 of the lattice structure 10 is designed as a composite wire. Several individual wires 11, in particular a part, for example 50% or 75% of all individual wires 11 or also all individual wires 11, ie 100% of the individual wires 11, can each be designed as composite wires. For this purpose, the individual wires 11 have an X-ray visible core material 11a and a superelastic sheath material 11b. The core material 11a can

in particular platinum, a platinum alloy, tantalum and / or a tantalum alloy. In any case, the core material 11a is preferably distinguished by increased visibility under X-rays. This ensures that the entire lattice structure 10 can be easily recognized by the surgeon during the implantation.

The jacket material 11b, however, is used to provide the

Self-expansion properties of the lattice structure 10. The

Jacket material 11b has super-elastic properties. In particular, the jacket material can be formed by a shape memory material that assumes a previously impressed shape under the influence of the ambient temperature. Such a shape memory material can in particular by a

Be formed nickel titanium alloy. The jacket material 11b is preferably adapted in such a way that when the body temperature of a person is reached, it forces the lattice structure 10 into the fully expanded state.

Depending on the desired size of the lattice structure 10 or the

medical device, in particular of the stent, it is expedient to adapt the diameter of the core material, the core diameter d _K e _m , accordingly. In particular, the self-expansion properties that

Compression capability and the X-ray visibility of the lattice structure 10 to be matched to one another in the best possible way. It has been shown that a core diameter d _K e _{m is} advantageous for different expansion diameters D _exp , which results from the product of the quotient of the expansion diameter De _xp and the number of meshes n of the meshes 12 of the mesh ring 13 and a visibility factor f. The visibility factor f is at least 0.08 and at most 0.15, in particular at most 0.12.

It has been shown in concrete terms that a core diameter calculated using the above parameters leads to good X-ray visibility of the

Lattice structure 10 leads, the lattice structure 10 continuing well

self-expanding and to a small compression diameter

is compressible. The formula applies here

DKERN = f (DEXP / P) for lattice structures 10 with different expansion _diameters D _exP .

In particular, the calculation of the core diameter Ü _K e _m on the basis of this formula leads to good parameters for lattice structures 10 that have a

Have expansion diameter D _exp between 2.5 mm and 8 mm. Such lattice structures 10 are particularly suitable for use in intracranial blood vessels.

In order to achieve good compressibility of the lattice structure 10, it is particularly advantageous if, as provided in the illustrated embodiments, the wire 11 Total pm a wire diameter dü _r a _ht of at most 65, especially at most 60 pm, especially not more than 55 pm , in particular at most 40 pm. In particular, the wire 11 may be a wire diameter dü _r a _ht between 30 pm and 65 pm, preferably between 40 pm and 50 pm have. Specifically, the wire diameter dü _r a _ht 40 may pm or 45 pm or be 50pm. Such thin wires enable a particularly high compression of the lattice structure 10, thus lead to a very small compression _diameter D _k0 m _P. This ensures that the

Lattice structure 10 can be easily guided to the treatment site through small catheters.

For lattice structures 10 with an expansion diameter D _exp between 2.5 mm and 3.5 mm, wire diameters dü _r a _ht between 30 μm and 40 μm have proven to be advantageous. For grid structures 10 with an expansion diameter D _exp between 3.5 mm, in particular 4 mm, and 5.5 mm have been found

Wire diameter dü _r a _ht pm between 30, in particular 38 pm, more

in particular more than 40 pm and 50 pm have proven advantageous. For

Grating structures 10 mm with an expansion diameter D _exp between 5.5, in particular 7 mm, and 8 mm dü _r a _ht have wire diameters between 42 pm, in particular 46 pm and pm proved 65 advantageous.

It has also been shown that for the self-expansion properties of the

Lattice structure 10, a wire 11 is advantageous whose jacket material has a thickness h of at least 10 μm. With a wire diameter dü _r a _ht of 40 pm, this results in a maximum possible core diameter of 20 pm. In FIG. 3 it can be clearly seen that a thickness h of 10 μm for the jacket material 11b with a wire diameter DDRAHT of 40 μm for the core material 11a Core diameter DKERN of at most 20 pm remains. The lower limit of the thickness h of the jacket material can also be at least 15 μm.

The percentage of the volume of the core material 11a in relation to the total volume of an individual wire 11 can be calculated from the aforementioned geometric specifications. This essentially corresponds to the quotient between the square of the ratio between the product of the visibility factor f and the mesh width b to the square of the wire diameter dü _r a _ht - Die

Mesh width b results from the ratio between the

Expansion _diameter D _exp and the number of meshes n. Specifically, the volume fraction cp of the core material 11a can thus be calculated as follows: y ⁼ (f Dexp / n) ² / d wire ²

Expressed as a percentage, it results that with a visibility factor f of 0.08 the volume percentage cp of the core material 11a based on the total volume of the wire 11 is from 15% to 25%, in particular from 18% to 22%.

With a visibility factor f of 0.1, the percentage of the total volume is preferably from 15% to 30%, in particular from 20% to 25%. With a visibility factor f of 0.12, the percentage of the total volume is preferably from 20% to 35%, in particular from 25% to 30%. With a visibility factor f of 0.15, the percentage of the total volume is preferably from 25% to 45%, in particular from 30% to 40%.

FIG. 2 shows a section of the lattice structure 10 of the medical device or of the stent according to FIG. 1. Specifically, FIG. 1 shows a single mesh 12 of the lattice structure 10, which is delimited by wire sections of a plurality of individual wires 11. As is customary in braided lattice structures 10, the mesh 12 has a diamond shape.

In Fig. 2 it is again made clear how the individual wire 11 is designed as a composite wire. In particular, for purposes of illustration, it is shown that the core material 11a runs through the individual wire 11 and is sheathed by the sheath material 11b. Under X-ray control, the core material 11a in particular can be seen, the X-ray density in the area of the crossovers 18 of the individual wire 11 being particularly high. The crossovers 18 are therefore particularly easy to see under X-ray control. The braiding angle α of the lattice structure 10 is in the illustrated

Embodiments preferably between 70 and 80 degrees, preferably

75 degrees, whereby a tolerance of ± 3 degrees can be provided. Of the

Braid angle a is regarded in the context of the present application as that angle which spans between a longitudinal axis of the lattice structure 10 and the individual wire 11. The single wire 11 is helical around the

Long axis twisted. This applies to all single wires.

In general, the invention is based on the following considerations:

For a product series of medical devices, in particular stents, the lattice structure of which has essentially the same structure in each case, but the individual products are distinguished by their expansion diameter D _exp

differ, it makes sense to increase the number of stitches n of the individual courses 13 with increasing expansion _diameter D _exp .

The width b of an individual mesh can generally be derived from the

Calculate the expansion _diameter D _exp and the number of meshes n as follows: b ⁼ 7i De _xp / n

The ratio D _exp / n between the expansion _diameter D _exp and the number of meshes n is used in the context of the present application as

Width ratio called RGS.

If the width ratio is RGS, the individual meshes are

comparatively wide. This has the disadvantage that embolic material, such as coils in an aneurysm, can only be retained with difficulty by the lattice structure 10.

With a small width ratio RGS, however, a small one results

Mesh width b. As a result, the lattice structure 10 becomes less flexible, so that it is more difficult to navigate the medical device through a catheter. A small mesh width b also means that microcatheters, which are used to introduce coils into an aneurysm, can only be guided through the meshes with difficulty. It is therefore appropriate to set a mesh width b that one

A compromise between the properties of a flow diverter which are important for aneurysm treatment (see above) and good navigability of the lattice structure 10 is achieved. It has been shown that a width ratio R _GS in a range from 0.1 mm to 0.3 mm leads to good results. Taking into account the circle number p, this results in a preferred mesh width b between 0.3 mm and 0.9 mm.

The width ratio R _GS between the expansion diameter D _EXP and the number of meshes n is between 2.5 mm and 3.5 mm, between 0.10 mm and 0.22 mm, in particular between 0.15 mm and 0, for an expansion diameter D _EXP , 20 mm. With an expansion diameter D _EXP between 3.5 mm and 6 mm, the width ratio R _GS between the expansion diameter D _EXP and the number of meshes n is preferably between 0.15 mm and 0.25 mm, in particular 0.18 mm and 0.22 mm, preferably about 0.2 mm. At a

The expansion diameter D _{EXP is} between 6 mm and 7 mm

Width ratio R _GS between 0.2 mm and 0.30 mm, in particular between 0.22 mm and 0.25 mm.

The braiding angle a influences the mechanical expansion behavior, the

Flexibility and deliverability of the medical device. A braiding angle a between 70 ° and 80 °, preferably 75 °, has proven to be well suited for the

Treatment of intracranial blood vessels by medical devices with a lattice structure 10 which has an expansion diameter D _exp between 2.5 mm and 8 mm has been proven.

At a predetermined width ratio R _GS and consequently a predetermined mesh width b and a predetermined braiding angle a results in a diamond shape and size of the mesh 12, from which in combination with the

Wire diameter dü _r a _ht a mesh density or a porosity results. The mesh density indicates the proportion of the total surface area of the lattice structure that is formed by the wire 11, ie minus the opening area of the meshes 12. The porosity, on the other hand, indicates the proportion of the overall surface area of the lattice structure that is formed by the sum of the opening areas of the meshes 12 is. The width ratio R _{GS also} influences the maximum inscribed circle diameter of the mesh 12, which is also referred to as the “pin opening”. The wire diameter dü _r a _ht , together with the braiding angle α and the width ratio RGS, influences the braid density or the porosity of the lattice structure 10 and also has an effect on the radial force and the feedability of the medical device. The following wire diameters dü _r a _ht have proven to be advantageous for different expansion diameters D _exp :

- with an expansion diameter D _exp between 2.5 mm and 4.5 mm, ie

2.5 mm <D _exp <4.5 mm: 30 pm <düraht <46 pm, and

- with an expansion diameter D _exp between more than 4.5 mm and 8 mm, ie 4.5 mm <D _exp <8 mm: 46 pm <dü _r a _ht <65 pm.

The length of the lattice structure 10 is preferably between 10 mm and 50 mm.

For good X-ray visibility, the wire 11 has an X-ray visible core material 11a with a core diameter d _K e _m . When choosing the

Core diameter d _K e _m , the size of the individual meshes 12 plays an important role. The wider and longer the meshes 12, the lower it is

Braid density of the lattice structure 10. A large core diameter d _K e _m in order to be able to recognize the wire 11 well under X-ray control.

In particular, the mesh width b influences the distance between the

Crossings 18 of a row of stitches 13. At the crossings 18

The intersecting sections of the wire 11 overlap and therefore form areas with increased X-ray density. The more the crossovers 18

are spaced apart from one another, the larger the core diameter d _K e _m should be in order to ensure good visualization of the lattice structure 10.

In particular, not only the surface of the lattice structure 10, but also the shape of the lattice structure 10, which adapts to the vessel wall, can be easily recognized by a large number of crossovers.

The width ratio RGS determines the density of the crossings 18 of a mesh row 13. The smaller the width ratio RGS, the smaller the distance between the crossings 18 and the higher the mesh density of the lattice structure 10. If the width ratio RGS is high, a relatively larger core diameter dKem is appropriate. For a small width ratio RGS, a correspondingly smaller core diameter d _K e _{m is} sufficient.

It has been shown that a ratio between the core diameter d _K e and the width ratio RGS between 0.08 and 0.15, in particular 0.10, further in particular 0.12, leads to good results. The aforementioned ratio results in the visibility factor f designated as such in the context of the present application.

With a visibility factor f of 0.08, with a width ratio RGS between 0.17 and 0.20 mm, an advantageous core diameter dKem between 13.3 pm and 16 pm results. For a larger width ratio, the RGS can be used

Increase core diameter d _K e _m up to 20 pm.

With a visibility factor f of 0.10, a width ratio RGS between 0.17 mm and 0.20 mm results in an advantageous core diameter dKem between 16.7 pm and 20 pm.

To have sufficient torsional resistance and thus a suitable one

To ensure restoring force in the spring-like deformation of the wire 11, it is advantageous if the jacket material 11b has a thickness h which

is at least 10 pm. With a maximum wire diameter dü _r a _ht of approx. 60 pm there is an upper limit for the core diameter d _K e _m of approx.

40 pm.

With an expansion diameter D _exp of 3.5 mm and a preferred wire diameter dü _r a _ht of 38 μm, the core diameter d _K e _{m must} not be greater than 18 μm, since otherwise the proportion of cladding material 11b would be too low. To achieve this, a visibility factor of 0.08 or 0.10 should be selected. With a larger expansion diameter D _exp , the preferred wire diameter dü _r a _{ht is,} for example, approx. 50 μm. For such lattice structures 10, the core diameter d _K e _{m can} consequently be up to 30 μm. In the case of a lattice structure 10 with an expansion diameter D _exp of 6 mm, a greater visibility factor f of up to approximately 0.15 would therefore be possible. A visibility factor f of 0.08 can be used if that

RGS width ratio is low or the wire diameter is high.

The choice of the suitable visibility factor f results in a percentage of the volume of the core material 11a in the total volume of the wire 11. With a visibility factor f of 0.08, the percentage of the volume of the core material in the total volume is preferably from 15% to 25%, in particular from 18% to 22%. Preferably for one

Visibility factor f of 0.1 the percentage of the total volume from 15% to 30%, in particular from 20% to 25%. With a visibility factor f of 0.12, the percentage of the total volume is preferably from 20% to 35%, in particular from 25% to 30%. With a visibility factor f of 0.15, the percentage of the total volume is preferably from 25% to 45%, in particular from 30% to 40%.

It has been shown in this context that for the following

Wire diameter dü _r a _{ht the} following core diameters d _K e _{m are} preferred:

For dü _r a _ht = 45 pm: d _K e _m = from 22 pm to 28 pm, in particular approx. 25 pm.

For dü _r a _ht = 50 pm: d _K e _m = from 24 pm to 35 pm, in particular from 26 pm to 32 pm, in particular approx. 27 pm or approx. 32 pm.

For dü _r a _ht = 55 pm: d _K e _m = from 27 pm to 38 pm, in particular from 29 pm to 36 pm, in particular approx. 30 pm or approx. 35 pm.

For the following expansion diameter D of the lattice structure are as follows _exp wire diameter dü _r a _ht advantageous:

Expansion diameter D _exp from 2.5 mm to 4.5 mm: wire diameter dü _r a _ht from 30 pm to 46 pm, in particular from 34 pm to 42 pm;

Expansion diameter D _exp > 4.5 mm to 6 mm: wire diameter dü _r a _ht from 42 pm to 55 pm, in particular from 46 pm to 50 pm;

Expansion diameter D _exp > 6 mm to 8 mm: wire diameter dü _r a _ht from 42 pm to 65 pm, in particular from 50 pm to 60 pm; The preferred thickness h of the jacket material is calculated as follows: h = (d üraht ^" dkern) / 2

The sheath material 11b consequently has a thickness h which, for the preferred wire diameter described above, dü _r a _ht at least 9 pm (for dü _r a _ht = 50 pm and dkem = 31.6 pm) and at most 12.4 pm (for düraht = 55 pm and dkem = 30.1 pm).

With regard to the number of meshes n, it is preferably provided that

Lattice structures 10 with an expansion _diameter D _exp between

2.5 mm and 8.0 mm, preferably about 12 to 36 meshes 12, in particular 16 to 32 meshes 12, per mesh ring 13.

Lattice structures 10 with an expansion diameter D _exp between 2.5 mm and

3.5 mm preferably have 16 to 20 meshes 12 per mesh ring 13. In the case of lattice structures 10 with an expansion diameter D _exp between 3.5 mm and 5.0 mm, mesh rings 13 with 20 to 26 meshes each can be provided. Lattice structures 10 with an expansion diameter D _exp between 5.0 mm and 8 mm preferably have a mesh number n of 26 to 32.

Bezuaszeichen

10 lattice structure

11 wire

11a core material

11b jacket material

12 stitches

13 mesh ring

14 longitudinal end

15 free

16 free

17 free

18 crossover

De _xp expansion _diameter

D _k o _mp compression _diameter

d _k e _m core diameter wire diameter

b mesh width

f visibility factor

h thickness of the jacket material 11b

RGS width ratio

a braid

ß mesh angle

n number of stitches

cp volume percent

Claims

MEISSNER BOLTE PO Box 860624 81633 Munich Acandis GmbH February 19, 2020 Theodor-Fahrner-Straße 6 M / CAN-323-PC 75177 Pforzheim JK Medical device, in particular flow diverters, and set claims

1. A medical device, in particular a flow diverter, with an at least partially tubular, radially self-expanding lattice structure (10) made of several interwoven individual wires (11) which form meshes (12) of the lattice structure (10), at least some of the individual wires (11 ) a radiopaque core material (11a) and a super-elastic one

Has jacket material (11b),

d a d u r c h e k e n n n z e i c h n e t that

a plurality of meshes (12) directly adjacent in the circumferential direction of the lattice structure (10) form a mesh ring (13), the lattice structure (10) in a completely self-expanded state having a

Expansion diameter D _exp , the mesh ring (13) has a number of stitches n and the core material (11a) has a core diameter d _K e _m , and the following applies to the core diameter d _K e _m : d | <em - f (Dexp / P) where for a visibility factor f applies:

0.08 <f <0.15. 2

2. Medical device according to claim 1,

dad u rch indicates that

the expansion diameter D _{exp is} from 2.5 mm to 8 mm.

3. Medical device according to one of the preceding claims,

dad u rch indicates that

a braiding angle α of the lattice structure (10) is from 70 ° to 80 °, in particular 75 °.

4. Medical device according to one of the preceding claims,

dad u rch indicates that

the wire (11) has a wire diameter dü _r a _ht that

with an expansion diameter D _exp of 2.5 mm to 4.5 mm:

30 pm <duraht <46 pm, and

with an expansion diameter D _exp of more than 4.5 mm to 8 mm: 46 pm <düraht <65 pm,

amounts.

5. Medical device according to one of the preceding claims,

dad u rch indicates that

the jacket material (11b) has a thickness which is at least 10 μm, in particular at least 15 μm, in particular from 10 μm to 20 μm.

6. Medical device according to one of the preceding claims,

dad u rch indicates that

the volume of the core material (11a) is a percentage of the

Total volume of the wire (11) occupies, with one

Visibility factor f from 0.08 to 0.15 the percentage of the

Total volume from 13% to 45%, in particular from 15% to 40%.

7. Medical device according to one of the preceding claims,

dad u rch indicates that

the volume of the core material (11a) is a percentage of the

Total volume of the wire (11) occupies, with one

Visibility factor f of 0.08 the percentage of the total volume is from 15% to 25%, in particular from 18% to 22%. 3

8. Medical device according to one of the preceding claims, dad u rch geken nzeich net that

the volume of the core material (11a) occupies a percentage of the total volume of the wire (11), with a

Visibility factor f of 0.1 the percentage of the total volume is from 15% to 30%, in particular from 20% to 25%.

9. Medical device according to one of the preceding claims, dad u rch geken nzeich net that

Visibility factor f of 0.12 the percentage of the total volume is from 20% to 35%, in particular from 25% to 30%.

10. Medical device according to one of the preceding claims, dad u rch geken nzeich net that

Visibility factor f of 0.15 the percentage of the total volume is from 25% to 45%, in particular from 30% to 40%.

11. Medical device according to one of the preceding claims, dad u rch geken nzeich net that

the lattice structure (10) in a completely compressed state has a compression _diameter D _k o _mP which is at most 0.7 mm, in particular at most 0.6 mm, in particular at most 0.51 mm, in particular at most 0.42 mm.

12. Medical device according to one of the preceding claims, dad u rch geken nzeich net that

the lattice structure (10) has closed loops (15) at one axial longitudinal end (14) and open wire ends at the other axial longitudinal end.

13. Medical device according to one of the preceding claims, dad u rch geken nzeich net that 4 the core material (11a) consists of platinum or a platinum alloy or of tantalum or a tantalum alloy.

14. Medical device according to one of the preceding claims,

dad u rch indicates that

the jacket material (11b) consists of a nickel-titanium alloy, in particular nitinol.

15. Medical device according to one of the preceding claims,

dad u rch indicates that

for the visibility factor f applies:

0.08 <f <0.14, in particular 0.08 <f <0.13, in particular 0.08 <f <0.12, in particular 0.08 <f <0.11, in particular f = about 0, 1.

16. Medical device according to one of the preceding claims,

dad u rch indicates that

the proportion of the individual wires (11) with the X-ray visible core material (11a) and the superelastic sheath material (11b) in the total number of individual wires (11) is at least 50%, in particular at least 75%, in particular 100%.

17. Medical device according to one of the preceding claims,

dad u rch indicates that

the number of meshes n of a mesh ring (13)

with an expansion diameter D _exp of 2.5 mm to 4.5 mm (2.5 mm <De _xp <4.5 mm): 12 <n <24, in particular 16 <n <24 and with an expansion diameter D _exp of more than 4.5 mm to 8 mm (4.5 mm <D _exp <8 mm): 24 <n <36, in particular 24 <n <

32

amounts.

18. Set with a medical device according to one of the preceding claims and a catheter, wherein the medical device can be arranged in a compressed state in a longitudinally displaceable manner in the catheter.

19. Set according to claim 18,

dad u rch indicates that 5 the medical device can be connected or connected, in particular detachably connected, to a transport wire.

20. Set according to claim 18 or 19,

dad u rch indicates that

- with an expansion diameter D _exp of 2.0 mm <D _exp <3.5 mm, in particular 2.5 mm <D _exp <3.5 mm, the catheter has an internal diameter of 2 Fr to 2.5 Fr, in particular 2 Fr, especially 2.5 Fr,

- With an expansion diameter D _exp of 3.5 mm <D _exp <5 mm, the catheter has an internal diameter of 2.5 Fr to 3 Fr, in particular 2.5 Fr and in particular 3 Fr and

- With an expansion diameter D _exp of 5 mm <D _exp, the catheter has an inner diameter of 3 Fr to 4 Fr, in particular 3 Fr, in particular 4 Fr

having.