DE102012112732B4 - Medical device, system with such a device and manufacturing method - Google Patents

Abstract

Medical device for covering an aneurysm neck (34) in the region of a vessel branch having a lattice structure (10) which can be converted from an expanded rest state into a compressed delivery state and at least one central longitudinal section (11) and two adjacent to the central longitudinal section (11), longitudinal longitudinal sections (12, 13), wherein the central longitudinal section (11) in the resting state of the lattice structure (10) has a maximum, first cross-sectional diameter which is greater than a maximum, second cross-sectional diameter of the edge-side longitudinal sections (12, 13), characterized in that the lattice structure (10) has a coarse-meshed region (17) and a narrow-meshed region (16), each of which forms an edge-side longitudinal section (12, 13) and a part of the central longitudinal section (11), the coarse-meshed region (17 ) over a first half of the grid structure (10) and the close-meshed area ch (16) extend over a second half of the grid structure (10).

Description

The invention relates to a medical device for covering an aneurysm neck in the region of a vessel branch. Furthermore, the invention relates to a system with such a device and a manufacturing method.

Aneurysms are blood vessel linings that can lead to serious medical complications. Due to the widening and stretching of the tissue of the vessel wall, there is the danger that the vessel wall ruptures in the area of the aneurysm. Such a rupture with the associated bleeding can, for example, lead to an undersupply of downstream blood vessels and tissue. If such aneurysmal rupture occurs in the region of the cerebral vessels, i. in the neurovascular area, this is called a bloody stroke.

Especially in the neurovascular area, there is a risk that aneurysms will form on branches of vessels. For example, the basilar artery divides into the two posterior cerebral arteries. In the area of this Y-shaped bifurcation, the blood is pulsed against the vessel wall, which is in alignment with the basilar artery, so that aneurysms easily form at this site.

The usual treatment of aneurysms is through the use of coils, which are introduced into the aneurysm. This is intended to influence the blood flow in the aneurysm and, in particular, to make it stop so that the vessel wall of the aneurysm, which is loaded by the pulsating blood flow, is relieved. In the treatment of aneurysms, it is common practice to place a stent in front of the aneurysm that prevents the coils from leaving the aneurysm and flushing with blood flow into downstream vessels. However, this is not possible in the area of vessel branches, in particular in the region of the branching basilar artery, with the necessary closure safety.

11 shows, for example, an aneurysm in the area of the vascular branching at the basilar artery. Into the aneurysm 30 ' are coils 31 ' brought in. About the basilar artery 32 ' is a stent 10 ' led to the treatment site. The stent 10 ' is arranged so that it extends from the basilar artery 32 ' into one of the posterior cerebral arteries 33 ' extends. This is how the stent covers 10 ' although partially the aneurysm 30 ' or the aneurysm neck 34 ' , However, the coverage is not complete, so there is a risk that coils 31 ' from the aneurysm 30 ' push out and into one of the side branches of the basilar artery 32 ' be rinsed. This is in 11 good to see.

US 2012/0290067 A1 and US 2012/0043703 A1 each disclose stents, which have a larger cross-sectional diameter in the implanted state in a central longitudinal section than in the peripheral longitudinal sections. By this bulge of the central longitudinal section, the mesh or cells of the central longitudinal section are enlarged and are therefore highly permeable to blood. These stents are therefore not suitable for shielding an aneurysm neck in a vascular branch.

The object of the invention is to specify a medical device which enables an efficient closure of an aneurysm, in particular an efficient covering of an aneurysm neck in the region of a branch of the vessel and possibly reduces the risk of thrombosis by means of coils emerging from the aneurysm. It is another object of the invention to provide a system with such a device and a manufacturing method.

According to the invention, this object is achieved with regard to the medical device by the subject-matter of claim 1, with regard to the system by the subject-matter of claim 17 and with regard to the manufacturing method by the subject-matter of claim 18.

The invention is based on the idea of specifying a medical device for covering an aneurysm neck in the region of a vessel branch, which has a lattice structure which can be converted from an expanded rest state into a compressed delivery state and at least one central longitudinal section and two adjacent to the central longitudinal section, has edge-side longitudinal sections. In the resting state of the lattice structure, the central longitudinal section has a maximum, first cross-sectional diameter that is greater than a maximum, second cross-sectional diameter of the longitudinal edge sections.

The grid structure has a coarse-meshed area and a close-meshed area, each forming an edge-side longitudinal portion and a portion of the central longitudinal portion, the coarse-meshed area extending over a first half of the grid structure and the close-meshed area extending over a second half of the grid structure

The term "resting state" preferably refers to the state of the grid structure in which the grid structure is completely unencumbered by force. The grid structure can then be completely expanded. The term "feed state" refers to the state of the grid structure in which the grid structure is compressed to the smallest possible cross-sectional diameter. The lattice structure further has an implanted state which is between the compressed feed state and the expanded idle state. When implanted, the lattice structure is partially expanded so that it can apply a radial force to the vessel wall. Thus, the grid structure is anchored in the vessel or body cavity.

Preferably, the grid structure is adapted such that at least the edge-side longitudinal sections exert a radial force on the hollow body vessel in the implanted state. At least the marginal longitudinal sections are therefore adapted to anchor the grid structure in the body cavity.

The lattice structure can have a longitudinal passage through hollow channel. In particular, the grid structure may be stented. At least the marginal longitudinal sections of the lattice structure can each have at least partially a hollow cylindrical basic shape. This ensures that the grid structure can be flowed through in the axial direction, in particular freely flowed through. In particular, the hollow channel can be designed free of installation, so that the flow through the grid structure are no obstacles in the way. The hollow cylindrical basic structure of the peripheral longitudinal sections also facilitates the section boundary of the edge-side longitudinal sections. Specifically, the edge-side longitudinal sections may extend from the longitudinal ends of the grid structure to a radial expansion associated with the central longitudinal section.

In a preferred embodiment of the medical device according to the invention, the transition between the first cross-sectional diameter and the second cross-sectional diameter is continuous or flowing. Essentially, it can be provided that the grid structure has a double funnel shape. The grid structure may include a proximal funnel-shaped portion and a distal funnel-shaped portion. In this case, the respective funnel-shaped section tapers to the outside. Concretely, the proximal, funnel-shaped section can taper in the proximal direction and the distal, funnel-shaped section can taper in the distal direction.

The central longitudinal section of the lattice structure, which has a larger cross-sectional diameter than the longitudinal edge sections, creates the possibility that the lattice structure lies completely over an aneurysm neck in the region of a branch of the vessel. The edge-side longitudinal sections can be arranged in body cavities branching off from one another and thus anchor the grid structure in the vascular system. The middle longitudinal section with the relatively larger cross-sectional diameter, however, can deform, so that it arched at least partially into another, branching hollow body vessel. Overall, the central longitudinal section can deform such that a secure coverage of the aneurysm is achieved.

For the deformation of the central longitudinal section, it is particularly advantageous if the central longitudinal section has a smaller radial force and / or a smaller radial pressure than the peripheral longitudinal sections. The grid structure can thus be constructed in the longitudinal direction such that it exerts different radial forces or radial pressures on the hollow body vessel. A high radial pressure or a high radial force promotes the anchoring of the lattice structure in the vessel. This function is to be taken over by the edge-side longitudinal sections, so that preferably a higher radial force or a higher radial pressure than in the central longitudinal section is advantageous in the edge-side longitudinal sections. By the middle longitudinal section has a smaller radial force or a smaller radial pressure than the edge-side longitudinal sections, this is particularly well deformable. Thus, the middle longitudinal section can adapt well to the vessel geometry of a branching of the vessel and, in particular, can fit well to an aneurysm neck. In particular, this prevents the lattice structure in a hollow body of the body from having its inner radius of curvature, i. on the side, which has a particularly small radius of curvature, lifts off the vessel wall. Rather, it is ensured that the grid structure is applied over the entire surface of the vessel wall. There are therefore no flow-calmed spaces between the lattice structure and the vessel wall, which favor the formation of thrombi.

With regard to the anchoring of the lattice structure in the hollow body of the hollow body and the deformation of the central longitudinal section, it has proven to be expedient if the radial force and / or the radial pressure of the central longitudinal section is at most 0.8 times, in particular at most 0.6 times, in particular at most 0.4 times, in particular at most 0.2 times, in particular at most 0.1 times, in particular at most 0.05 times, corresponds to the radial force and / or the radial pressure of the marginal longitudinal sections.

When measuring the radial force or the radial pressure, an oversizing of the lattice structure is taken into account. Concretely, the lattice structure has a cross-sectional diameter which, over the entire length of the lattice structure, is greater than the cross-sectional diameter of the hollow body vessel into which the lattice structure is to be inserted. As the lattice structure automatically forces itself into the expanded state of rest, it exercises in the hollow body vessel, which satisfies this urge due to the counteracts a smaller cross-sectional diameter, a radial force or a radial pressure on the vessel wall. The measurement of the radial force or the radial pressure takes place in a partially compressed state of the lattice structure, wherein the lattice structure has a cross-sectional diameter which is smaller by 0.5 mm or by 1 mm than in the rest state. In this respect, an oversizing of 0.5 mm or 1 mm is taken into account in the measurement of the radial force or the radial pressure. In this state, the longitudinal section preferably effects a radial force or a radial pressure in the ratio described above relative to the edge-side longitudinal sections.

Furthermore, it can be provided that the edge-side longitudinal sections of the grid structure have different cross-sectional diameters. In particular, a distal, edge-side longitudinal section in the resting state of the lattice structure may have a smaller cross-sectional diameter than a proximal, edge-side longitudinal section. This takes account of a distally tapering cross-sectional geometry of hollow body vessels.

At rest, the grid structure may have a rotationally symmetric basic shape. The rotationally symmetrical basic shape is particularly advantageous for the production of the lattice structure. Thus, the lattice structure may simply be formed on a braiding mandrel by braiding wires or by cutting from a tubular starting material. In particular, the lattice structure can be produced by laser cutting from a rotationally symmetrical, in particular hollow cylindrical, starting material and subsequently formed by a heat treatment so that the middle longitudinal section results with the cross section diameter larger than the cross sectional diameter of the peripheral longitudinal sections. At rest, the grid structure may have an annular bulge, which forms the central longitudinal section. The bulge can be formed in a braided lattice structure by varying the braiding angle during braiding on a braiding mandrel.

In general, the lattice structure can be so flexible that the lattice structure takes on an asymmetric shape under the action of external forces. In particular, the lattice structure can adapt to the shape of the hollow body vessel, in particular the vessel branching. The asymmetry refers to the longitudinal axis of the lattice structure. When the lattice structure has a rotationally symmetrical basic shape in the resting state, a symmetrical shape can be seen in a side view of the lattice structure. The adaptation and displacement of the central longitudinal section in the implanted state, an asymmetrical shape can be taken. This allows the comparatively high flexibility of the lattice structure.

In the specific application in which the lattice structure is used in a vessel branch, it is particularly preferred if the lattice structure is so flexible that the two marginal longitudinal sections can each be arranged in two body cavities arranged at an angle to one another, the middle longitudinal section being deformable in this way in that an aneurysm neck, which is arranged opposite one of the two body cavities arranged at an angle to one another, can be covered by the central longitudinal section. This ensures that any coils introduced into the aneurysm are kept there.

In a further preferred embodiment of the invention, the lattice structure has a stable and a metastable state, wherein the lattice structure has a straight longitudinal axis in the stable state and a curved longitudinal axis in the metastable state. In particular, the lattice structure can be designed in such a way that the lattice structure changes from the stable state into the metastable state through an external, in particular lateral force action. This principle is basically known from toy frogs which comprise a spring made of a spring steel strip. When the spring is pressed, it changes from a stable to a metastable state, which generates a noise. A similar principle is applicable to the invention. In this case, the stable state may preferably correspond to the rest state or to all states in which the lattice structure has a straight axis of rotation. During implantation, the stable state can be left by a lateral force action, for example by deflecting the lattice structure to introduce a marginal longitudinal section into a branching blood vessel. In this case, the grid structure may be formed so that it automatically jumps over in a pre-embossed curved shape. In this metastable state, the lattice structure preferably has a curved longitudinal axis. At the same time, the grid structure, in particular the central longitudinal section, can change into an asymmetrical shape and thus cover the neck of the aneurysm.

In a further preferred embodiment of the invention, the lattice structure has a coarse-meshed region and a narrow-meshed region. Both the coarse-meshed region and the narrow-meshed region each form an edge-side longitudinal section and a part of the central longitudinal section. In other words, the proximal or distal funnel-shaped portion of the grid structure may have a coarse-meshed area or a close-meshed area. Basically, the mesh size along the Change grid structure. Preferably, the grid structure in a proximal funnel-shaped section has a different mesh size than in a distal, funnel-shaped section.

The coarse-meshed region extends over a first half of the lattice structure. The close-meshed area extends over a second half of the grid structure. According to the invention, it is provided that the close-meshed region forms a distal half, in particular a distal, funnel-shaped section, of the lattice structure. The distal funnel-shaped portion is preferably placed in the area of the aneurysm so that the narrow mesh in this area efficiently prevents coils from escaping from the aneurysm. Alternatively, the narrow mesh area can affect the flow into the aneurysm so that the use of coils can be dispensed with altogether. By contrast, the coarse-meshed region, which can form the distal, funnel-shaped section of the lattice structure, allows blood flow to flow through the proximal, funnel-shaped region or the first half of the lattice structure. This is particularly advantageous if the coarse-meshed region is arranged in the vessel branch such that the blood flow through the coarse-meshed region can be conducted into a branched body hollow vessel. Thus, the risk of thrombosis is reduced in the field of vascular branching.

The central longitudinal section may comprise cells or meshes which have a larger cell angle or mesh angle than the cells or meshes of the peripheral longitudinal sections. In this way, the bulge of the central longitudinal section is comparatively easy to produce.

In principle, the lattice structure can be formed by webs or filaments, wherein the webs or filaments in the central longitudinal section have a smaller web width or filament thickness than in the peripheral longitudinal sections. This further increases the flexibility of the central longitudinal section and promotes the adaptability of the central longitudinal section to the vessel geometry in a vessel branch.

In addition, the flexibility of the central longitudinal section compared to the marginal longitudinal sections and thus the adaptability of the central longitudinal section to the geometry of the vessel branch, which leads to an efficient coverage of the aneurysm, can be increased by the lattice structure in the central longitudinal section a smaller wall thickness than in the Having edge longitudinal sections.

According to a side-by-side aspect, the invention is based on the idea of specifying a system with a previously described device and a feed device, in particular a lock or a catheter. In this case, the grid structure can be arranged longitudinally displaceable within the feed device in the compressed feed state and be connected or connectable to a transport wire.

Another subsidiary aspect of the invention relates to a method for producing a device as described above, wherein a shaping mandrel is provided, which is formed substantially rotationally symmetrical and having an annular bulge in a central region. The grid structure of the medical device is subsequently formed on the shaping mandrel by braiding filaments or by laser cutting and a subsequent shaping heat treatment.

• 1: eine Seitenansicht einer medizinischen Vorrichtung;
• 2: die medizinische Vorrichtung im implantierten Zustand;
• 3: eine erfindungsgemäße medizinische Vorrichtung im implantierten Zustand, wobei die Gitterstruktur der Vorrichtung zwei Bereiche mit unterschiedlichen Maschengrößen aufweist;
• 4: eine medizinische Vorrichtung im implantierten Zustand, wobei die Gitterstruktur der Vorrichtung drei Bereiche mit unterschiedlichen Maschengrößen aufweist;
• 5: die medizinische Vorrichtung gemäß 1 im stabilen Zustand;
• 6: die medizinische Vorrichtung gemäß 5 im metastabilen Zustand;
• 7: eine medizinische Vorrichtung, wobei die Gitterstruktur einen beidseitig asymmetrisch ausgewölbten mittleren Längsabschnitt aufweist;
• 8: eine medizinische Vorrichtung, wobei die Gitterstruktur einen einseitig asymmetrisch ausgewölbten mittleren Längsabschnitt aufweist;
• 9: eine medizinische Vorrichtung, wobei die randseitigen Längsabschnitte unterschiedlich orientierte Längsachsen aufweisen;
• 10: eine schematische Seitenansicht der Gitterstruktur einer medizinischen Vorrichtung, wobei die Zellgeometrien der einzelnen Längsabschnitte der medizinischen Vorrichtung gezeigt sind; und
• 11: eine Ansicht eines herkömmlichen Stents bei der Anordnung in einer Gefäßverzweigung.

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

• 1 a side view of a medical device;
• 2 : the medical device in the implanted state;
• 3 a medical device according to the invention in the implanted state, the lattice structure of the device having two regions with different mesh sizes;
• 4 a medical device in the implanted state, the lattice structure of the device having three regions of different mesh sizes;
• 5 : the medical device according to 1 in stable condition;
• 6 : the medical device according to 5 in the metastable state;
• 7 a medical device, the lattice structure having a bilaterally asymmetrically bulged central longitudinal section;
• 8th a medical device, wherein the grid structure has a unilaterally asymmetrically bulged central longitudinal section;
• 9 a medical device, wherein the longitudinal edge portions have differently oriented longitudinal axes;
• 10 FIG. 2: a schematic side view of the lattice structure of a medical device, wherein the cell geometries of the individual Longitudinal sections of the medical device are shown; and
• 11 Fig. 3: A view of a conventional stent when placed in a vascular branch.

The medical device is preferably designed as a stent. In particular, the medical device, in particular the stent, is suitable for implantation in a body hollow vessel.

The invention aims to provide a medical device which allows the covering of an aneurysm neck in the region of a branch of the vessel. Specifically, this applies to covering an aneurysm neck in a basilar head aneurysm.

The medical device or stent has a grid structure 10 which is convertible from an expanded idle state to a compressed delivery state. The grid structure 10 can be formed as a grid mesh. In this case, a plurality of filaments, in particular wires, can be intertwined in order to form a grid-like mesh structure as a whole. Preferably, the grid structure is designed as a 1-over-1 braiding. This means that in each case one filament crosses every other crossing filament and intersects the respectively intervening, intersecting filament.

Alternatively, the grid structure 10 also from integrally connected webs 22 be formed, the cells 21 limit. The preparation of the lattice structure can be achieved by free cutting the cells 21 made of a full tube. The starting material for the production of such a stent or such a grid structure 10 can therefore be a metal tube into which, preferably by a laser, the cells 21 be cut. This will make the webs 22 exposed. Alternatively, it is possible to use the lattice structure 10 to produce by a deposition process.

Basically, the grid structure 10 formed substantially tubular and has a passageway. Through the passageway also extends the longitudinal axis of the grid structure 10 , Perpendicular to the longitudinal axis, the grid structure 10 expand or be crimped. Preferably, the grid structure 10 Self-expanding executed. The grid structure 10 thus has a radial force or a radial pressure, which is the lattice structure 10 to expand.

1 shows the grid structure 10 at rest, especially in the fully expanded state. In this state act on the lattice structure 10 no external forces. It is well recognizable that the lattice structure 10 three mutually distinguishable longitudinal sections 11 . 12 . 13 having. A first longitudinal section 12 forms a proximal marginal longitudinal section 12 , The proximal longitudinal section 12 can, as in 1 is shown, a bevelled end of the lattice structure 10 include. The bevelled end or the proximal end edge 14 allow recapture of the grid structure 10 in a catheter, even if the lattice structure 10 was completely expanded. For this purpose, it is specifically provided that the proximal end edge 14 over the entire circumference of the closing margin 14 is smooth. At the same time is the end edge 14 obliquely with respect to the longitudinal axis of the lattice structure 10 arranged so that the end edge 14 can slide back into a catheter and at the same time the lattice structure 10 in the compressed state urges. For clarity, the end edge 14 shown in simplified form. In practice, the finishing edge 14 transition into a tip or an extension which extends substantially in alignment with the wall plane of the lattice structure. The tip or extension may be connectable to a transport wire. The compound is preferably detachable, in particular electrolytic, so that the grid structure can be decoupled from the transport wire after correct positioning in the hollow body vessel.

On the proximal longitudinal section 12 follows a middle longitudinal section 11 the lattice structure 10 , The middle longitudinal section 11 differs from the proximal longitudinal section 12 by a larger cross-sectional diameter. Specifically forms the lattice structure 10 in the area of the middle longitudinal section 11 an annular bulge 15 , The annular bulge 15 extends over the entire circumference of the lattice structure 10 , In particular, the annular bulge extends 15 in the embodiment according to 1 evenly over the entire circumference of the lattice structure 10 ,

The grid structure 10 also has a second edge-side longitudinal section 13 , in particular a distal edge-side longitudinal section 13 , on. The distal longitudinal section 13 has a cross-sectional diameter that is substantially equal to the cross-sectional diameter of the proximal longitudinal section 12 equivalent. It is also possible, that the distal longitudinal section 13 a different cross-sectional diameter than the proximal longitudinal section 12 having. For example, the distal longitudinal section 13 a larger or smaller cross-sectional diameter than the proximal longitudinal section 12 respectively. The choice of the cross-sectional diameter is incumbent on the person skilled in the art, which takes into account optionally preferred radial forces during the implantation into different blood vessels. In any case, the distal longitudinal section 13 a smaller cross-sectional diameter than the middle longitudinal section 11 on. It is also possible that the distal longitudinal section 13 a smaller cross-sectional diameter than the proximal longitudinal section 12 having. In particular, the distal longitudinal section 13 have a cross-sectional diameter which is at least 0.5 mm, in particular at least 1 mm, smaller than the cross-sectional diameter of the proximal longitudinal section 12 is. In principle, in particular for all embodiments of the invention, the middle longitudinal section applies 11 has the largest cross-sectional diameter, ie, comprises a cross-sectional diameter which is greater than the cross-sectional diameter of the proximal longitudinal section 12 is. The aforementioned cross-sectional diameters relate to the rest state of the lattice structure.

The middle longitudinal section 11 preferably has a flexibility that is greater than the flexibility of the marginal longitudinal sections 12 . 13 is. This can be achieved, for example, by reducing the web width or the filament thickness of the lattice structure. Furthermore, the flexibility in the middle longitudinal section 11 opposite the marginal longitudinal sections 12 . 13 be achieved by a corresponding braid angle or web angle. The increased flexibility in the middle longitudinal section 11 allows a good deformation of the central longitudinal section 11 , so that this in a vascular branch to an aneurysm neck 34 can create.

1 also shows that the grid structure 10 in the middle longitudinal section 11 is bulged. In the area of the maximum cross-sectional diameter of the central longitudinal section 11 forms the lattice structure 10 a curvature directed radially outward. The curvature points in the region of the central longitudinal section 11 in which the maximum cross-sectional diameter of the lattice structure 10 is recognizable in the resting state, in particular in the region of the middle longitudinal section 11 bisecting cross-sectional plane, a curvature radius WR preferably at most 0.5 times, in particular at most 0.4 times, in particular at most 0.3 times, in particular at most 0.2 times, in particular at most 0.1 times the maximum cross-sectional diameter the lattice structure 10 or the middle longitudinal section 11 having. This ensures that the middle longitudinal section 11 in the case of a transaxial excursion in the implanted state within a vascular branch, it adapts well to the geometry of the vascular branch, and in particular can bulge at least partially into another branching vessel.

2 shows the lattice structure described above 10 when implanted in a vascular branch. An example is the vascular branching of the basilar artery 32 showing the basilar artery 32 into a first cerebral artery 33a and a second cerebral artery 33b divides. Between the two cerebral arteries 33a . 33b is frontal and in alignment with the basilar artery 32 an aneurysm 30 arranged. The aneurysm 30 has an aneurysm neck 34 on, which is the entrance gate to the aneurysm 30 forms. In the transition between the basilar artery 32 and the first cerebral artery 33a is the lattice structure 10 used. The grid structure 10 lies in the blood vessels such that a proximal longitudinal section 11 in the basilar artery 32 and a distal longitudinal section 13 in the first cerebral artery 33a is arranged. The marginal longitudinal sections 12 . 13 are at least partially expanded or expanded, so that they have a radial pressure on the vessel walls of the basilar artery 32 or the first cerebral artery 33a exercise. This is how the lattice structure becomes 10 or generally held the stent in the blood vessel.

The middle longitudinal section 11 is arranged substantially centrally within the vessel branch. By the deflection of the lattice structure 10 distinguished by the arrangement of the lattice structure 10 in the angled vessels (eg basilar artery 32 and first cerebral artery 33a) results, is on the middle longitudinal section 11 applied a lateral force, which leads to a deformation of the central longitudinal portion 11 leads. This creates a lateral bulge 18 leading to the second cerebral artery 33b urges. In this way, the middle longitudinal section covers 11 the aneurysm neck 34 , The aneurysm 30 is thus well cut off from the blood flow in the vasculature. True, in the aneurysm 30 Coils may be introduced, preferably before the lattice structure 10 is used. However, it is also possible to treat the aneurysm 30 completely without coils to solve, as with the cover of the aneurysm neck 34 through the highly flexible grid structure 10 the flow in the aneurysm is already sufficiently reduced so that the risk of rupture is reduced.

In 3 an embodiment of the medical device or the stent according to the invention is shown. The grid structure 10 is in its form substantially analogous to the embodiment according to 1 and 2 educated. 3 shows the implanted state of the lattice structure 10 where a bulge 18 is formed, which is in another side branch, here the second cerebral artery 33b extending vessel branching. In addition, it is provided that the grid structure 10 into a coarse mesh area 17 and a tight-knit area 16 is divided. The subdivision is carried out in the embodiment according to 3 in half. That means that the tight-knit area 16 on the one hand by an edge-side longitudinal section, here the distal longitudinal section 13 , and a part, especially half, of the middle longitudinal section 11 is formed. The coarse-meshed area 17 on the other hand, it extends over the proximal longitudinal section 12 and a part of the middle longitudinal section 11 , In general, the lattice structure 10 according to 3 be considered as a double funnel shape when the grid structure 10 at rest. Here is a funnel-like section as coarse-meshed area 17 and another funnel-like section as a close-meshed area 16 educated.

In principle, it is conceivable, the central longitudinal section 11 to divide into several parts. For example, the middle longitudinal section 11 a distal part and a proximal part. The distal part comes to lie in the implanted state, preferably in the region of the aneurysm neck. Therefore, it is preferable if the distal part of the central longitudinal section 11 at least on one, in particular the aneurysm-facing side, a close-meshed area 16 forms. The proximal part of the middle longitudinal section 11 may be substantially the same structure as the marginal longitudinal sections 12 . 13 and in particular a coarse mesh area 17 form.

How out 3 is clearly recognizable, causes the close-meshed area 16 a good coverage of the aneurysm 30 so that the flow within the aneurysm 30 efficiently reduced or even blocked. By contrast, the coarse-meshed area 17 fluid permeable. That means the blood that passes through the basilar artery 32 enters the vascular branch, not just through the passageway into the first cerebral artery 33a but about the relatively large meshes of the coarse-meshed area 17 also in the second cerebral artery 33b arrives. Thus, there is a risk of deficiency of tissue downstream of the second cerebral artery 33b lies, avoided.

4 shows a medical device in the implanted state. In essence, the lattice structure is similar 10 according to 4 the lattice structure 10 according to 3 , In contrast to the embodiment according to the invention, however, in the device according to 4 provided that both marginal longitudinal sections 12 . 13 a close-knit area 16 form. According to 4 So are the marginal longitudinal sections 12 . 13 with the close-meshed area 16 Provided. The middle longitudinal section 11 is, however, with a coarse mesh area 17 Provided. The close-knit area 16 of the distal longitudinal section 13 however, extends partially into the middle longitudinal section 11 into it so that ensures the aneurysm 30 or the aneurysm neck 34 at least for the most part from the close-knit area 16 is covered. The close-knit area 16 in the proximal longitudinal section increases the adhesion of the lattice structure 10 in the basilar artery 32 or generally in the body cavity. The close meshing also improves the endothelialization.

The coarse-meshed area 17 extends over a large part, in particular almost completely, over the central longitudinal section 11 , At least the coarse-meshed area extends 17 so far over the middle longitudinal section 11 that ensures that the second cerebral artery 33b , ie a branching hollow body vessel, exclusively from the coarse-meshed area 17 is covered to ensure sufficient blood flow into the branching hollow vessel, here the second cerebral artery 33b , to ensure.

5 essentially shows the lattice structure 10 according to 1 , The presentation 1 That's why in 5 repeated to the transition of the lattice structure 10 from a stable state, as in 5 is shown to indicate a metastable state which is in 6 you can see. The stable state of the lattice structure 10 is preferably formed by the resting state. At rest, the lattice structure points 10 preferably a straight longitudinal axis, in particular a straight axis of rotation. However, the longitudinal axis is not necessarily equated with a rotation axis, since there are also embodiments of the invention, which have a different shape from the rotationally symmetrical shape. This will be discussed later. In general, it should be noted that when using a symmetrical basic shape of the lattice structure 10 Advantageously, the grid structure is avoided 10 to align in the blood vessel. Rather, it is a symmetrical lattice structure 10 generally aligned correctly in the blood vessel during implantation.

The metastable state, the 6 shows is by jumping the grid structure 10 reached. In the metastable state, the lattice structure decreases 10 a previously impressed shape. The grid structure 10 can between the stable state ( 5 ) and the metastable state ( 6 ). This principle is basically known from crackpot frogs or hair clips.

In the metastable state after 6 has the lattice structure 10 a curved longitudinal axis. The previously annular bulge 15 So shifts laterally in the transition from the stable state to the metastable state. This leads to a lateral bulge 18 and one of the lateral bulge 18 radially opposite lateral curvature 19 , It mainly becomes the middle longitudinal section 11 deformed. The marginal longitudinal sections 12 . 13 retain their shape largely. The longitudinal axes of the marginal longitudinal sections 12 . 13 aligned in the stable state of the lattice structure 10 and may be in the metastable state of the lattice structure 10 be oriented differently, in particular skew or be arranged crossing. The longitudinal axes R1 . R2 the marginal longitudinal sections 12 . 13 are in 9 represented by dash-dotted lines. In this case, the longitudinal axis of the distal longitudinal section 13 with R1 and the longitudinal axis of the proximal longitudinal section 12 denoted by R2.

It is also possible that the longitudinal axes R1 . R2 the marginal longitudinal sections 12 . 13 already at rest are skewed to each other or are arranged crossing each other. 9 also provides a grid structure 10 in the idle state. In the illustration according to 9 it can be seen that the longitudinal axes R1 . R2 the marginal longitudinal sections 12 . 13 essentially within the proximal longitudinal section 13 cross. Preferably, however, is the distal longitudinal section 13 so aligned that the longitudinal axes R1 . R2 the marginal longitudinal sections 12 . 13 in the middle longitudinal section 11 , in particular in a transverse axial center plane crossing the grid structure 10 halved. The distal longitudinal section 13 may be substantially mirrored at the transverse axial center plane to the proximal longitudinal section 12 be educated.

The grid structure 10 according to 9 is asymmetrically shaped at rest. Asymmetric are generally referred to forms that are not rotationally symmetric.

In this context, it should be noted that the rotational symmetry with respect to the lattice structure 10 does not necessarily require a solid body. In the context of the application, lattice structures are also referred to as rotationally symmetrical if the lattice structures are arranged in a wall plane which is arranged rotationally symmetrically about a longitudinal axis as a virtual plane.

The 7-9 show asymmetric lattice structures 10 , where the asymmetry is already at rest. Such grid structures may be adapted to the shape of the treatment site.

In the device according to 7 is provided that the middle longitudinal section 11 a lateral bulge 18 having. The lateral bulge 18 is asymmetrically shaped in itself. That means the bulge 18 partially formed differently strong. The bulge 18 is thus in the circumferential direction of the lattice structure 10 partially pronounced than circumferentially adjacent areas. So is according to 7 For example, provided that the bulge 18 on one side of the grid structure 10 is more pronounced than on the radially opposite side. The weaker lateral bulge is designated 18a.

In the device according to 8th is the lateral bulge 18 arranged substantially one-sided. Radially opposite the bulge 18 has the lattice structure 10 no bulge up. Rather, the lattice structure 10 radially opposite the lateral bulge 18 shaped in a straight line. In other words, the lattice structure 10 according to 8th a lateral bulge 18 on, the opposite, in particular radially opposite, a straight wall area 20 the lattice structure 10 extends. The lateral bulge 18 is in the middle longitudinal section 11 pronounced or arranged. The straight wall area 20 extends over the entire length of the grid structure 10 ,

The grid structure 10 according to 9 structurally corresponds essentially to the lattice structure 10 according to 6 , in which 9 the resting state of the lattice structure 10 shows. 6 on the other hand shows a metastable state.

In general, it is provided in the invention that the lattice structure 10 or the stent is divided into three sections. There will be a proximal longitudinal section 12 , a middle longitudinal section 11 and a distal longitudinal section 13 distinguished. In the middle longitudinal section 11 has the lattice structure 10 a different structure than in the proximal longitudinal section 12 and / or distal longitudinal section 13 on. The middle longitudinal section 11 can be divided into subsections or parts. At least in a subsection or part of the central longitudinal section 11 can the grid structure 10 a different structure than in the proximal longitudinal section 12 and / or in the distal longitudinal section 13 respectively. This applies to all embodiments of the invention.

For example, the grid structure of webs 22 be formed, the cells limit. In 10 are exemplary individual cells 21 each shown in juxtaposition a portion of the lattice structure 10 form. It's easy to see that the cells 21 of the middle longitudinal section 11 a different shape or geometry than the cells 21 the marginal longitudinal sections 12 . 13 respectively. For example, the cells 21 in the middle longitudinal section a larger or wider web angle 22 as the cells 21 in the marginal longitudinal sections 12 . 13 respectively. Preferably, the angle is y the cells 21 in the middle longitudinal section 11 at least 90 °, in particular at least 100 °, in particular at least 110 °, in particular at least 120 °, in particular at least 130 °, in particular at least 150 °. The angle refers to the angle between two, possibly imaginary, straight connections between the four tips of a cell 21 , The calculation of the angle is therefore based on an ideal cell, the straight webs 22 having. In general, it can be provided that the cell 21 has a diamond-shaped or parallelogram-like basic structure. The larger the bridge angle y in the middle longitudinal section 1 is, the greater is its flexibility. In this respect, it is preferable if the web angle y in the middle longitudinal section 11 or a subsection or a half of the central longitudinal section 11 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 °, greater than in at least one edge-side longitudinal section 12 . 13 is. Preferably, the web angle y in the cells 21 the marginal longitudinal sections 12 . 13 identical.

In addition to high flexibility, the middle longitudinal section 11 preferably, ensure that the lattice structure 10 It adapts well to variable vessel diameter, it is advantageous if the web angle y in the middle longitudinal section 11 , at most 90 °, in particular at most 80 °, in particular at most 70 °, in particular at most 60 °. So if a grid structure 10 should be provided, which can adapt well to variable vessel diameter, then it is advantageous if the web angle y in the middle longitudinal section 11 or a subsection or a half of the central longitudinal section 11 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 °, smaller than the web angle y in the marginal longitudinal sections 12 . 13 is.

In principle, it is expedient if in the middle longitudinal section 11 a high deformability and adaptability of the lattice structure 10 given is. It is therefore hardly a high radial force, but rather is a high flexibility of the central longitudinal section 11 in the foreground. This can be achieved for example by a small web width. The web width is preferably at most 30 μm, in particular at most 25 μm, in particular at most 20 μm, in the middle longitudinal section 11 , Preferably, the web width is in the middle longitudinal section 11 at least 5 μm, in particular at least 10 μm, in particular at least 15 μm, smaller than in the edge-side longitudinal sections 12 . 13 , in particular smaller than in the proximal edge portion 11 and / or in the distal edge portion 13 ,

The adaptability of the lattice structure 10 , in particular the middle longitudinal section 11 , on the vessel geometry, ie the flexibility of the lattice structure 10 or its central longitudinal section 11 , Alternatively or additionally, can be adjusted by a suitable wall thickness. So can the grid structure 10 in the middle longitudinal section 11 a smaller wall thickness than in the marginal longitudinal sections 12 . 13 respectively. The wall thickness in the central longitudinal section is preferably at least 5 μm, in particular at least 10 μm, in particular at least 15 μm, in particular at least 20 μm, in particular at least 25 μm, in particular at least 30 μm, in particular at least 40 μm in at least one, preferably both, of the peripheral longitudinal sections 12 . 13 , The wall thickness of the middle longitudinal section 11 is preferably at most 55 μm, in particular at most 45 μm, in particular at most 35 μm, in particular at most 25 μm, in particular at most 20 μm, in particular at most 15 μm.

With regard to the length dimensions of the lattice structure 10 it is preferred if the central longitudinal section 11 measured along the longitudinal axis of the lattice structure 10 has a length which is at least 0.3 times, in particular at least 0.5 times, in particular at least 0.8 times, in particular at least 1 times, in particular at least 1.5 times, the length of one of marginal longitudinal sections 12 . 13 is. In this way it is ensured that the bifurcation region, ie the region of the branching of the vessel, passes well through the central longitudinal section 11 is filled. The maximum length is the middle longitudinal section 11 3 times, in particular at most 2.5 times, in particular at most 2 times, in particular at most 1.5 times, the length of one of the marginal longitudinal sections 12 . 13 in order not to impair anchoring of the grid structure or of the stent in the hollow body vessels, which emanate from the vessel branching. The determination of the length of the marginal longitudinal sections 12 . 13 is preferably only along the edge portions of the grid structure 10 , which have a constant cross-sectional diameter, in particular a hollow cylindrical shape. These edge sections form the marginal longitudinal sections 12 . 13 ,

To get a good fixation of the lattice structure 10 In the field of vessel branching or in the bifurcation region, it is advantageous to have a relatively large ratio between the cross-sectional diameter and the length of the central longitudinal section 11 to choose. Preferably, the ratio between the cross-sectional diameter of the middle longitudinal section 11 and the length of the middle longitudinal section 11 at least 0.5, in particular at least 0.8, in particular at least 1, in particular at least 1.5, in particular at least 2. This ensures that the central longitudinal section 11 fills the bifurcation area and especially the aneurysm neck 34 covered. The ratio between the cross-sectional diameter of the central longitudinal section 11 and the length of the middle longitudinal section 11 may be at most 4, in particular at most 3, in particular at most 2.

The middle longitudinal section 11 differs from the marginal longitudinal sections 12 . 13 by its cross-sectional diameter. It is preferred if the ratio between the cross-sectional diameter of the central longitudinal section 11 and the cross-sectional diameter of the edge-side longitudinal sections 12 . 13 at least 1.2, in particular at least 1.4, in particular at least 1.6, in particular at least 1.8, in particular at least 2.0, in particular at least 2.2, in particular at least 2.5, in particular at least 3.0, in particular at least 3 , 5, in particular at least 4.0.

The above values generally apply to the idle state of the grid structure 10 , Furthermore, the values for the cross-sectional diameter of the individual longitudinal sections always apply to the maximum cross-sectional diameter in the respective section. These basic definitions apply to all embodiments of the invention.

The middle longitudinal section 1 not only can have a constant or uniform structure. Rather, it may be advantageous if the middle longitudinal section 11 has a variable structure, which changes in particular from proximal to distal. For example, the distal part of the central longitudinal section 11 a higher number of cells 21 as the proximal part of the middle longitudinal section 11 respectively. This has advantages in terms of influencing the flow in the area of the aneurysm neck 34 , Preferably, the middle longitudinal section can be 11 into a distal part and a proximal part, wherein the ratio between the number of cells in the proximal part of the central longitudinal section 11 and in the distal part of the longitudinal section 11 is less than 1, in particular less than 0.8, in particular less than 0.5, in particular less than 0.25. The distal and the proximal part of the middle longitudinal section 11 may also, independently of each other, have a plurality of subsections which have a different number of cells 21 include.

In general, in the context of the application that counts the number of cells 21 over the circumference of the grid structure 10 is determined. In particular, form several cells 21 the lattice structure 10 each one cell ring extending over the entire perimeter of the lattice structure 10 extends. For comparing the number of cells 21 in different sections of the lattice structure 10 will be the number of cells 21 used in the cell rings of the individual sections. The number of longitudinally adjacent cells 21 is irrelevant for the comparison of the number of cells.

With regard to the system with the described medical device and a feed device, it is advantageous if the grid structure 10 is compressible such that it can be arranged in a feed device, in particular a catheter, with an inner diameter of at most 0.7, in particular at most 0.6, in particular at most 0.5, in particular at most 0.42, in particular at most 0.4. The grid structure 10 In general, the medical device or stent may be connectable to a transport wire. Preferably, the grid structure 10 electrolytically decoupled from the transport wire or generally the feeder.

Overall, the medical device, in particular the lattice structure 10 , have a length of less than 35 mm, in particular less than 25 mm, in particular less than 15 mm. The marginal longitudinal sections 12 . 13 may have a cross-sectional diameter which is less than 12 mm, in particular less than 10 mm, in particular less than 8 mm. For the stability of the lattice structure 10 it is beneficial if the cross-sectional diameter is at least 4 mm, in particular at least 6 mm. The cross-sectional diameter of the central longitudinal section, in particular the maximum cross-sectional diameter of the central longitudinal section, is preferably less than 12 mm, in particular less than 10 mm, in particular less than 8 mm and / or not more than 5 mm, in particular more than 6 mm. The mentioned cross-sectional dimensions and length dimensions generally refer to the resting state of the lattice structure 10 , wherein the middle longitudinal section 11 in the resting state of the lattice structure 10 has a maximum, first cross-sectional diameter which is greater than a maximum, second cross-sectional diameter of the edge-side longitudinal sections 12 . 13 is.

Furthermore, it can be provided that the grid structure 10 Has marker elements that include increased radiopacity. The marker elements are preferably at the boundary between narrow-meshed areas 16 and coarse mesh areas 17 arranged. Further, marker elements may be at the axial ends of the lattice structure 10 be arranged. For example, the axial ends of the grid structure 10 Eyelets or eyes carry the marker elements. The eyelets may be at cell tips at the axial end of the lattice structure 10 be arranged.

As can be clearly seen in the figures, the transition from the marginal longitudinal section 12 . 13 to the middle longitudinal section 11 continuously or by a continuous or continuous curvature. In this respect, the dimensional data with respect to the cross-sectional diameter basically refer to the maximum cross-sectional diameter present in the respective longitudinal section. This can, for example, in the device according to 1 at the middle longitudinal section 11 in half of the lattice structure 10 available.

LIST OF REFERENCE NUMBERS

10

lattice structure

10 '

stent

11

middle longitudinal section

12

proximal longitudinal section

13

distal longitudinal section

14

proximal end edge

15

annular bulge

16

close-meshed area

17

coarse-meshed area

18

lateral bulge

18a

weaker pronounced lateral bulge

19

lateral curvature

20

straight wall area

21

cell

22

web

30, 30 '

aneurysm

31 '

coil

32, 32 '

basilar artery

33a, 33a '

first cerebral artery

33b, 33b '

second cerebral artery

34, 34 '

aneurysm neck

y

web angle

R1

Longitudinal axis of the distal longitudinal section 13

R2

Longitudinal axis of the proximal longitudinal section 12

WR

radius of curvature

Claims (18)

Medical device for covering an aneurysm neck (34) in the region of a vessel branch having a lattice structure (10) which can be converted from an expanded rest state into a compressed delivery state and at least one central longitudinal section (11) and two adjacent to the central longitudinal section (11), longitudinal longitudinal sections (12, 13), wherein the central longitudinal section (11) in the resting state of the lattice structure (10) has a maximum, first cross-sectional diameter which is greater than a maximum, second cross-sectional diameter of the edge-side longitudinal sections (12, 13), characterized in that the lattice structure (10) has a coarse-meshed region (17) and a narrow-meshed region (16), each of which forms an edge-side longitudinal section (12, 13) and a part of the central longitudinal section (11), the coarse-meshed region (17 ) over a first half of the grid structure (10) and the close-meshed area I (16) extend over a second half of the grid structure (10). Device after Claim 1 , characterized in that the lattice structure (10) has a hollow axial flow-through hollow channel. Device after Claim 1 or 2 , characterized in that the edge-side longitudinal sections (12, 13) each have at least partially a hollow cylindrical basic shape. Device according to one of the preceding claims, characterized in that the transition between the first cross-sectional diameter and the second cross-sectional diameter is continuous. Device according to one of the preceding claims, characterized in that the central longitudinal section (11) has a smaller radial force and / or a smaller radial pressure than the marginal longitudinal sections (12, 13), in particular wherein the radial force and / or the radial pressure of the central longitudinal section (11). 11) at most 0.8 times, in particular at most 0.6 times, in particular at most 0.4 times, in particular at most 0.2 times, in particular at most 0.1 times, in particular at most 0 , 05 times, in particular at most 0.02 times, the radial force and / or the radial pressure of the peripheral longitudinal sections (12, 13) corresponds. Device according to one of the preceding claims, characterized in that the edge-side longitudinal sections (12, 13) have different cross-sectional diameters, in particular wherein a distal, edge-side longitudinal section (13) in the rest state of the grid structure (10) has a smaller cross-sectional diameter than a proximal, edge-side longitudinal section (13). 12). Device according to one of the preceding claims, characterized in that the grid structure (10) has a rotationally symmetrical basic shape in the rest state. Device according to one of the preceding claims, characterized in that the grid structure (10) in the rest state, an annular bulge (15) which forms the central longitudinal portion (11). Device according to one of the preceding claims, characterized in that the lattice structure (10) is flexible such that the lattice structure (10) assumes an asymmetric shape under the action of external forces, in particular adapts to the shape of the hollow body vessel. Device according to one of the preceding claims, characterized in that the lattice structure (10) is flexible such that the two edge-side longitudinal sections (12, 13) in each case in two mutually angularly arranged body cavities can be arranged, wherein the central longitudinal portion (11) is deformable in that one of the two body cavities arranged at an angle relative to one another can be covered by the middle longitudinal section (11) arranged opposite the neck of the aneurus (32). Device according to one of the preceding claims, characterized in that the lattice structure (10) has a stable and a metastable state, wherein the lattice structure (10) in the stable state has a straight longitudinal axis and in the metastable state has a curved longitudinal axis. Device after Claim 11 , characterized in that the lattice structure (10) is formed such that the lattice structure (10) by an external, in particular lateral, force from the stable state to the metastable state jumps. Device according to one of the preceding claims, characterized in that the central longitudinal section (11) has cells (21) or meshes which have a larger cell angle or mesh angle than the cells (21) or meshes of the marginal longitudinal sections (12, 13). Device according to one of the preceding claims, characterized in that the grid structure (10) by webs (22) or filaments is formed, wherein the webs (22) or filaments in the central longitudinal section (11) has a smaller web width or filament thickness than in the edge-side longitudinal sections (12, 13), in particular wherein the web width or filament thickness is at least 5 μm, in particular at least 10 μm, in particular at least 15 μm, smaller than in the marginal longitudinal sections 12, 13. Device according to one of the preceding claims, characterized in that the grid structure (10) in the central longitudinal section (11) has a smaller wall thickness than in the edge-side longitudinal sections (12, 13), in particular wherein the wall thickness of at least 5 microns, in particular at least 10 microns , in particular at least 15 .mu.m, in particular at least 20 .mu.m, in particular at least 25 .mu.m, in particular at least 30 .mu.m, in particular at least 40 .mu.m, smaller than in at least one, preferably both, of the peripheral longitudinal sections 12, 13. Device according to one of the preceding claims, characterized in that the device comprises a stent for covering an aneurysm neck (34) in the region of a vessel branch. System having a device according to one of the preceding claims and a feed device, wherein the grid structure (10) is arranged in the compressed feed state longitudinally displaceable within the feed device and connected to a transport wire or connectable. Method for producing a device according to one of Claims 1 to 16 wherein a shaping mandrel is provided, which is substantially rotationally symmetrical and has an annular protrusion in a central region, and wherein on the forming mandrel then the lattice structure (10) of the medical device is formed by braiding filaments or by depositing a metal alloy ,

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