DE102018107594B4 - Medical device for intravascular treatment and manufacturing method - Google Patents

Abstract

Medical device for intravascular treatment with an at least partially tubular lattice structure (10) made of webs (11) connected to one another in one piece and delimiting cells (12), four webs (11) being connected to one another by a web connector (13) and at least one X-ray visible wire element (20, 20') is provided, which is guided along at least one web (11) and in an end section (10b) of the lattice structure (10) a loop (21, 21') with a first leg (22a, 22a') and forms a second leg (22b, 22b'), the loop (21, 21') dividing the wire element (20, 20') into a first section (23a, 23a') and a second section (23b, 23b'), the first section (23a, 23a') and/or the second section (23b, 23b') winding around a plurality of webs (11) which each form a row of webs (14) in alignment with one another, and the row of webs (14) being helical runs through it around a longitudinal axis of the lattice structure (10). characterized in that the first leg (22a, 22a') and the second leg (22b, 22b') radially inside the lattice structure (10) or the first leg (22a, 22a') and the second leg (22b, 22b') radially are arranged outside of the lattice structure (10).

Description

The invention relates to a medical device for intravascular treatment according to the preamble of patent claim 1. A medical device of this type is disclosed, for example DE 10 2014 115 533 A1 known. Furthermore, the invention relates to a method for producing the medical device.

Thrombectomy devices, also known as stent retrievers, consist of a tubular lattice structure with bars delimiting individual cells. Such lattice structures are usually laser cut from a shape memory material such as nitinol. The proximal end of the lattice structure is connected to a transport wire. An example of such a thrombectomy device is from WO 2012/106657 A2 known. To improve the X-ray visibility of the thrombectomy device, X-ray visible wires are routed along the bars of the lattice structure. The wires loosely wrap around the webs. It must be prevented in a constructive manner that the wires can be displaced or even come loose when using the thrombectomy device. The positioning of the device is particularly problematic, in particular pulling it back into the catheter when the thrombectomy device is to be repositioned. The wires can block the compression of the lattice structure if the X-ray visible wire is unfavorably superimposed on the lattice structure.

The medical device mentioned in accordance with DE 10 2014 115 533 A1 solves this problem in that the wires form loops at the proximal end of the lattice structure, which loop around the bar connectors arranged between the bars in such a way that the wires are fixed longitudinally and axially. This improves safety when positioning as well as securing the wires to the lattice structure. It has been shown that relatively large forces are required for the compression of such thrombectomy devices.

The invention is based on the object of improving a medical device of the type mentioned at the outset such that the lattice structure of the device can be compressed relatively easily without impairing the functional reliability of the device.

According to the invention, this object is achieved by a medical device having the features of claim 1. Specifically, the object is achieved by a medical device for intravascular treatment, in particular for removing thrombi, with a lattice structure that is tubular at least in sections and has webs that are connected to one another in one piece. The webs delimit cells, with three or four webs being connected to one another by a web connector. At least one X-ray-visible wire element is provided, which is guided along at least one web and forms a loop with a first leg and a second leg in an end section of the lattice structure. The loop divides the wire element into a first section and a second section, with the first section and/or the second section winding around a plurality of webs which each form a row of webs aligned with one another. The row of webs runs helically around a longitudinal axis of the lattice structure. As a result, a corresponding pattern is achieved through the wire element or a corresponding course of the wire element, which ensures particularly good recognition or visibility.

According to the invention it is provided that the first leg and the second leg are arranged radially inside the lattice structure. Alternatively, the first leg and the second leg are arranged radially outside of the lattice structure.

The loop consists of two legs and a loop that connects the two legs. The wire section in the immediate vicinity of the loop arc is to be understood as the leg. The leg has a length that extends at least to the first crossing with a web. In other words, both legs are arranged at least up to and including the first crossing with a web on the same side (radially inside or radially outside) of the lattice structure. The two legs cross different webs in the area of the first crossing.

The legs are thus decoupled from the lattice structure in such a way that the lattice structure is not impeded by the wire element during compression. It goes without saying that after the first crossing, the legs of the loop are or can be arranged further on the same side (radially inside or radially outside) of the lattice structure, at least over a certain distance.

As the lattice structure progresses, the wire element changes sides of the lattice structure, i.e. from radially inside to radially outside or vice versa. For example, the change can take place in the area of the proximal end of the end cell. The change can take place even further proximally, for example in the area of another cell proximally adjacent to the end cell.

The wire element can then turn into turns along the webs.

The legs enclose an angle which is determined by the arc of the loop. The loop and the legs are always arranged on the same radial side of the lattice structure.

A certain relative movement between the wire element and the lattice structure is permitted by the invention, so that the movement of the cells during compression or expansion in the circumferential and longitudinal direction of the lattice structure occurs as undisturbed as possible. The same applies to the effect of foreshortening, in which the overall length of the lattice structure changes when it is compressed or expanded. By arranging the two legs radially inside the lattice structure or radially outside the lattice structure, a mechanical decoupling of the wire element from the lattice structure is achieved in the area of the distal end section of the lattice structure. As a result, a relative movement between the lattice structure and the wire element is possible in this area.

The decoupled arrangement of the wire element in a certain area of the lattice structure, namely in the area of the end section, also means that the remaining area of the lattice structure and the wire element can be connected to one another relatively firmly, at least so firmly that the security against slipping of the wire element is relatively to the lattice structure is essentially maintained. In any case, there is the possibility of designing the connection between the wire element and the lattice structure in such a way that the functionality of the device is retained without impairing the ease of movement of the device when it is compressed.

The decoupling is limited to the area of the loop. The loop can, for example, extend to the first crossing point.

In a preferred embodiment, the loop is substantially stress free, i.e., there are no residual stresses, by heat treatment in the expanded rest state of the device.

The invention is applicable, for example, to the stent retriever manufactured by the applicant with the brand name APERIO, the basic structure of which is described in the granted patent DE 10 2014 115 533 B1 the applicant is described in more detail. The invention is explicitly disclosed and claimed in connection with this device. This well-known thrombectomy device is suitable for rapid recanalization and has a hybrid cell design. This achieves excellent wall apposition and thrombus integration. The X-ray visible wire element can be attached to the lattice structure of the stent retriever without further ado. The hybrid cell design includes small, closed cells that ensure excellent apposition to the vessel wall and secure thrombus uptake. The comparatively larger cells with integrated anchoring elements ensure effective retention of the thrombi and safe, atraumatic removal.

The connection of four webs by a web connector does not rule out the lattice structure having web connectors that connect fewer than four webs, for example three webs. In a hybrid mesh with different cells, normal cells can be formed by web connectors with four main webs and sub-cells can be formed by web connectors with three webs.

The invention can also be used with other thrombectomy devices.

In general, the medical device designed according to the invention can form an implant, for example a stent, or an instrument that can be used temporarily, such as the thrombectomy device described above.

In general, it is noted that the medical device has a tubular lattice structure that is radially expandable. In this case, the tubular lattice structure can be automatically transferred from a radially compressed to a radially expanded state, for example by utilizing the shape memory effect. In this respect, the medical device preferably has a self-expanding lattice structure.

The lattice structure can, for example, be tubular in sections or in its entirety.

In a preferred embodiment of the medical device as a thrombectomy device, it can preferably be provided that the lattice structure is tubular in sections, with the tubular shape merging into a funnel-shaped or conical section at a proximal end of the lattice structure. The tapered section forms a transition of the lattice structure into a catheter in which, in use, the device extends in a compressed state. The tapered section has the function of enabling retractability. The advantage is evident in the compressed state of the device. Due to the legs of the wire elements arranged radially outside or radially inside, or the loop arranged inside or outside, there is relative freedom of movement between the X-ray-visible wires and the lattice structure. This will reduce tension in the catheter is reduced and less feeding force is required for reinsertion into the catheter. The relative mobility is particularly advantageous in the axial direction, since it can be assumed that the loop moves in this direction and its position varies when it is pulled in and out.

The invention is not limited to a thrombectomy device, but also includes other medical devices.

The term “distal” means a side of the lattice structure that is remote from the user of the device. The term "proximal" means a user-facing side of the medical device, i.e., a side closer to the user.

Preferred embodiments of the invention are given in the subclaims.

In a preferred embodiment, the end section is a distal end section. This has the advantage that the relative freedom of movement between the loop and the lattice structure is favored.

For example, in an expanded state of the lattice structure, the loop can be arranged between two distal end cells of the lattice structure that are adjacent in the circumferential direction. Alternatively, the loop can be arranged within a distal end cell of the lattice structure in an expanded state of the lattice structure. If there are several wire elements, both alternatives can be combined. As a result, a pattern or a distribution of the loops on the circumference of the lattice structure is achieved, especially with a plurality of wire elements with a corresponding number of loops, so that the lattice structure can be compressed or expanded as unhindered as possible.

The arrangement of the two legs radially inside or radially outside of the lattice structure is possible in both variants (within a distal end cell and between two adjacent distal end cells).

The invention does not rule out the possibility that the device can be offset in the radial direction when it is in use, so that the loop is offset somewhat inwards. In the resting state or generally in the expanded state, the two legs are arranged radially inside or radially outside of the lattice structure. In the expanded state, it is still possible to distinguish between the position of the legs and the loop. However, particularly in the compressed state, the legs or the loop cannot be assigned exactly to the cells.

In the foregoing embodiment, where the loop is located between two circumferentially adjacent distal end cells, the first leg and the second leg may each pass through one of the end cells. As a result, the inner or outer loop is fed to the lattice structure over a relatively short distance, so that, apart from the distal end section, good fixation of the wire element on the lattice structure is possible.

In an expanded state of the lattice structure, the loop is preferably arranged at a distance from a distal web connector of the lattice structure in the distal direction, in particular by at least one web width, preferably by at least 25% of a web length, more preferably by at least 50% of a web length. This embodiment supports the free movement of the lattice structure in the region of the distal end section because the distance between the loop and the distal web connector allows a free path along which the lattice structure and the wire element can move relative to one another.

In a preferred embodiment, the wire element is wound around a row of webs in such a way that the wire element achieves a full winding, in particular a winding of 360° along the row of webs after one web, in particular after 2 webs, in particular after 3 webs.

The wire element can be formed by a fully radiopaque wire or a composite wire with a radiopaque core. The latter is known, for example, under the term DFT (Drawn-Filled-Tubing) wire and has the advantage that good biocompatibility of the wire element is associated with the X-ray visibility function.

To improve X-ray visibility, 2, 3 or 4 wire elements can be provided, each of which forms a loop in the distal end section of the lattice structure. According to the invention, the loop is formed in such a way that the first and second legs of the loop are arranged radially inside the lattice structure or radially outside the lattice structure.

In a further embodiment, the sections of the wire elements can cross regularly along the lattice structure, with at least two, in particular at least three and at most eight, in particular at most six webs of a row of webs being arranged between two crossing points. As a result, the pitch of the wire element along the lattice structure or along a central axis of the lattice structure to be influenced. In a preferred embodiment, exactly three webs of a row of webs are arranged between two crossing points.

In a further preferred embodiment, at most four loops, each with a first leg and a second leg, are arranged in a distal end section of the lattice structure. The first leg and the second leg are arranged radially inside or radially outside of the lattice structure.

The lattice structure can have at least one web extension on a proximal end section, which is positively connected to a distal coupling piece of a transport wire. Two web extensions are preferably provided. This creates a secure connection between the lattice structure and the transport wire. This embodiment is particularly well suited as a thrombectomy device.

The web extension can have an engagement element which engages with a precise fit in a recess of the coupling piece which extends transversely to a longitudinal axis of the transport wire. As a result, the axial forces occurring when the device is moved in a feed system are reliably transmitted.

For additional security, a crimp sleeve can be provided, which encompasses the web extension and the coupling piece.

A particularly good fixation of the wire element on the lattice structure is achieved in that the open ends of the wire elements are guided through the crimp sleeve in such a way that the open ends of the wire elements ideally end approximately flush with the proximal end of the sleeve or just far enough out of the protrude from the proximal end in order to be fully bonded. This ensures that the wire element is held securely at the proximal end or area of the transport wire.

The protruding wire end can be connected to the transport wire, for example, by means of an adhesive-filled coil, the coil enclosing the protruding wire end and the transport wire. This provides additional security against unintentional detachment of the thrombectomy device from the transport wire.

Alternatively, the protruding end of the wire can be glued directly to the transport wire.

A method for producing a medical device according to the invention is also disclosed and claimed within the scope of the invention. The method includes the heat treatment of at least one wire element, so that the wire element is largely stress-free in the expanded or partially expanded state. In particular, the loop of the wire element can thus be moved and retracted in the catheter with a lower feed force. The wire element and thus the loop want to go into their expanded state after reaching the transformation temperature. Below this temperature, the lattice structure can be compressed without tension by pulling it back into the catheter.

The invention is described in more detail below using an exemplary embodiment with reference to the attached schematic figures.

• 1 eine medizinische Vorrichtung nach einem erfindungsgemäßen Ausführungsbeispiel, wobei die Gitterstruktur in einem flach ausgebreiteten Zustand dargestellt ist;
• 2 eine Detailansicht der Vorrichtung nach Anspruch 1 im Bereich des distalen Endabschnitts;
• 3 eine perspektivische Ansicht des Transportdrahts mit dem Kopplungsstück;
• 4 eine perspektivische Ansicht des Transportdrahts nach 3 mit eingelegtem Stegfortsatz und einer halbdurchsichtig gezeichneten Crimphülse (Zwischenmontagezustand);
• 5 der Transportdraht nach 3 mit Drahtelementen (Zwischenmontagezustand);
• 6 der Transportdraht nach 3 im finalen Montagezustand;
• 7 ein alternatives Ausführungsbeispiel des Transportdrahtes.

In these show

• 1 a medical device according to an embodiment of the present invention, wherein the lattice structure is shown in a flat, unfolded state;
• 2 a detailed view of the device according to claim 1 in the region of the distal end section;
• 3 a perspective view of the transport wire with the coupling piece;
• 4 a perspective view of the transport wire 3 with inserted web extension and a semi-transparent crimp sleeve (intermediate assembly state);
• 5 the transport wire 3 with wire elements (intermediate assembly state);
• 6 the transport wire 3 in the final assembly state;
• 7 an alternative embodiment of the transport wire.

1 shows a medical device with a lattice structure 10 made up of cells 12, which are formed from a plurality of webs 11 connected to one another in one piece. For reasons of presentation, in 1 resorting to an unfolded view in which the lattice structure 10 is shown longitudinally sectioned and laid out flat. It goes without saying that the lattice structure 10 is actually tubular. The tubular shape results from the fact that the lattice structure 10 is cut from a tubular material, in particular laser-cut. Other geometries of the lattice structure are always possible and are explicitly mentioned in the introduction to the description. In addition to laser cutting, other manufacturing processes are possible.

In 1 a state of rest is shown in which no external forces act on the lattice structure 10 . In the compressed state, the webs 11 are in close contact with one another, resulting in a smaller cross-sectional profile for the lattice structure 10 . The webs 11 delimit cells 12. It is provided that four webs 11 each delimit a cell 12 at least in certain areas. The webs 11 form a diamond-shaped cell 12 or a cell 12 with a diamond-shaped basic structure (closed cell design).

The webs 11, each delimiting a cell 12, are coupled to one another by web connectors 13. Four webs 11 go out from each web connector 13 . The web connectors 13 are each integrated in one piece with the webs 11 in the lattice structure 10 . The web connectors 13 essentially form crossing points of the webs 11. Each web 11 forms a direct connection between two web connectors 13. The web connectors 13 are preferably distributed over the lattice structure 10 in a pattern. The webs 11 can have the same or different web widths.

In this case, it can be provided that in each case two opposite webs aligned parallel to one another can have the same web width. The webs 11 lying parallel to one another each form a pair of webs, it being possible for the web width of the webs 11 of the web pairs of a cell 12 to differ from one another. In other words, each cell 12 has a first pair of bars and a second pair of bars, the bars 11 of the first pair of bars having a different bar width than the bars 11 of the second pair of bars. A cell designed in this way is called an asymmetric cell. The formation of the lattice structure 10 by asymmetric cells increases the bending flexibility of the lattice structure, so that the medical device can be used well in curved blood vessels.

The web widths vary between 30 μm and 60 μm, preferably between 36 μm and 54 μm. In the proximal end area 10a, the webs 11 are up to 90 μm wide. The wall thickness is between 60 µm and 100 µm.

The invention is not limited to a lattice structure with symmetrical cells, but can also be used for a lattice structure with asymmetrical cells.

The lattice structure 10 has a hybrid cell design with a large number of small closed cells 12 and cells 12c which are larger than the small cells 12 . The small cells 12 enable a good apposition of the lattice structure 10 to the vessel wall. The larger cells 12c have integral anchoring elements 12d which, in use, effectively retain the thrombus to be removed and provide for safe, atraumatic removal of the thrombus. Areas of use are also conceivable in which no hybrid cell design is necessary and the anchoring elements 12d can be omitted.

As in 1 clearly visible, the device has at least one wire element 20, specifically two wire elements 20, 20'. It is possible that more than two wire elements are provided, for example a total of 3 or 4 wire elements, which are distributed in a pattern around the circumference.

The wire element or wire elements are formed from an X-ray-visible material. For example, it can be a solid material made of an X-ray-visible material. It is also possible to use a composite material, for example so-called DFT wire elements. Such wire elements have a core wire made of an X-ray-visible material, for example platinum, tantalum or gold, and a sheath made of a shape-memory material. An example of a DFT wire element has a platinum core with a diameter of 40-60 µm and a nitinol sheath with an outer diameter equal to the core diameter plus approx. 20 µm. Other materials and varied dimensions or just an X-ray-visible wire without a super-elastic sheath would also be conceivable.

In general, all X-ray visible materials commonly used for implants can be used.

As in 1 As can be seen, the wire element 20 forms a loop 21 which is arranged in the area of the distal end section 10b of the lattice structure 10 . The distal end section 10b forms the axial end of the tubular lattice structure 10 which emerges first when the device is released from a catheter.

In the area of the loop 21, the wire element 20 changes its direction in such a way that the wire element is guided out of the lattice structure 10 and back in again. The loop 21 has a first leg 22a and a second leg 22b which extend at an angle to one another. Between the two legs 22a, 22b, the wire element 20 forms a curved section which connects the two legs 22a, 22b.

According to the initial example 1 two wire elements 20, 20' are provided, each of which is constructed accordingly. Accordingly, the second wire element 20' has two legs 22a', 22b', which together form the second Form loop 21'. The two loops 21, 21' are constructed essentially identically. The statements below in connection with the first loop 21 apply correspondingly to the second loop 21'.

The two legs 22a, 22b of the first loop 21 are arranged radially inside the lattice structure 10. In the example according to 1 this means that the two legs 22a, 22b are arranged behind the lattice structure 10 in the image plane. It is possible that the two legs 22a, 22b are arranged radially outside of the lattice structure. This corresponds to an embodiment in which the in 1 Legs 22a, 22b shown are arranged in front of the lattice structure 10 in the image plane.

Specifically, the first loop 21 is arranged in the area of the end cells 12, 12a, 12b, i.e. in the outermost row of cells of the lattice structure 10 in the axial direction. The two legs 22a, 22b of the first loop 21 are passed through the end cells 12, 12a, 12b in the same direction and are both located on one and the same side of the lattice structure 10 in the region of the end section 10b avoided in the area of the end portion 10b. The loop 21 can move essentially freely in relation to the lattice structure 10 . As a result, the loop 21 is decoupled from the lattice structure 10 .

In addition, the loop 21, specifically the area in which the loop 21 changes direction, is at a distance from the distal web connector 13b. The distal bar connector 13b is the bar connector 13 which is arranged at the outermost point in the axial direction.

The loop 21 projects somewhat in the axial direction beyond the adjacent end cells 12a, 12b. It is sufficient if the loop 21 is arranged loosely in front of the distal web connector 13b, since the loop 21 is decoupled from the lattice structure 10 by the arrangement of the two legs 22a, 22b on one and the same side of the lattice structure 10. The spacing of the loop 21 from the distal web connector 13 ensures even better that the loop 21 does not impede the movements of the lattice structure 10 . The loose arrangement of the loop arch can extend somewhat further into the lattice structure 10 in the proximal direction.

The distance between the distal bridge connector 13b and the loop 21 can be at least 25% of a bridge length, in particular at least 50% of a bridge length. The maximum distance of the loop 21 from the distal bridge connector 13b should not be more than the axial end of the lattice structure 10. In other words, the loop 21 should not protrude in the axial direction beyond the lattice structure 10, specifically beyond the free ends of the end cells 12, 12a, 12b.

According to the example 1 In the expanded state of the lattice structure 10, the loop 21 is arranged between two circumferentially adjacent distal end cells 12a, 12b. In other words, the loop 21 extends at least in sections into the free space that is formed between the two adjacent end cells 12a, 12b. As an alternative or in addition, the loop 21 can be arranged inside a distal end cell (not shown), it also being the case here that the two legs of the loop 21 are arranged on one and the same side of the lattice structure 10 .

X-ray markers, for example three distal PtIr point markers, can be arranged on some distal end cells 12, 12b of the lattice structure 10. In contrast to the prior art, the wire elements 21, 21' are not fixed by the x-ray markers in the region of the distal end section 10b.

In general, the loops 21, 21' form free wire sections which extend beyond the webs 11 of the immediately adjacent end cells 12A, 12B.

According to the example 1 is the first leg 22a through the in 1 left distal end cell 12a and the second leg 22b through the in 1 right distal end cell 12b, specifically in the same direction from the inside to the outside, so that the entire loop 21 is arranged completely outside the lattice structure, ie radially outside the lattice structure 10. It also applies here that the decoupling of the loop 21 can also take place in the opposite direction, ie when the two legs 22a, 22b are guided in the opposite direction, ie from the outside to the inside.

According to the initial example 1 the fixing of the wire element 20 takes place outside of the end section 10b, specifically from the row of cells directly adjoining the distal end cells 12, 12a, 12b. In other words, the distal row of the end cells 12, 12a, 12b is the area in which the wire element 20 or the loop 21 is arranged loosely on the lattice structure 10. The region of the loose arrangement of the loop 21 can extend somewhat further into the lattice structure 10, for example up to and including the second row of cells 12. In order not to disrupt the functionality of the lattice structure, the loose arrangement of the loop 21 should be limited to a distal area. The larger area of the lattice structure 10 is used to attach the wire element 20.

The arrangement of the loop 21 radially inside the lattice structure 10 is shown in FIG 2 illustrated detailed view of the lattice structure 10 can be seen particularly well. It can be seen that the two legs 22a, 22b coming from the lattice structure 10 are guided over the webs 11 of the adjacent cells 12 and dip into the distal end cells 12, 12a. The two legs 22a, 22b are passed through the distal end cells 12a, 12b in the same direction, so that the two legs 22a, 22b are both arranged on the same side of the lattice structure 10, specifically on the inside. The loop 21 is arranged radially inward and axially inward, ie the lattice structure 10 extends axially over the end of the loop.

For attachment, the wire element 20 is braided into the lattice structure 10 in some areas and/or wrapped around individual webs 11 of the lattice structure 10. Several wire elements 20 can be interwoven with the lattice structure 10 independently of one another and/or wrap around the individual webs 11 of the lattice structure 10.

The wire element 20 can run essentially parallel or laterally along the webs 11 . In general, the wire element 20 preferably extends along a row of webs 14 formed by a plurality of webs arranged one behind the other. In 1 shows the arrow provided with the reference number 14 in the direction of the row of webs 14. The row of webs 14 preferably runs helically around the longitudinal axis of the lattice structure 10. Further webs 11 extend laterally from the row of webs 14, with the wire element 20 alternatingly crossing under or crossing the laterally extending webs 11 can cross. In this way, the wire element 20 is securely braided into the lattice structure 10 . In addition, the wire element 20 can wrap around the webs 11 of the row of webs 14 .

The wire element 20 is divided by the distal loop 21 into two sections 23a, 23b. The two sections 23a, 23b can be wound parallel to one another in a helical manner around the longitudinal axis of the lattice structure 10. It is also possible for the first section 23a and the second section 23b to extend along different rows of webs 14 so that the first section 23a and the second section 23b cross one another once or several times in the longitudinal direction of the lattice structure 10 . In 1 It can be clearly seen that the wire element 20, which is guided from the proximal end 10a to the distal end 10b, where it is deflected at a distal loop 21b and led back into the lattice structure 10, crosses itself several times.

If a plurality of wire elements 20, 20', specifically two wire elements 20, 20', are provided, the respective first and second sections 23a, 23a', 23b, 23b' can overlap, resulting overall in a diamond-shaped pattern of X-ray-visible wire elements (see Fig. 1 , flat spread lattice structure). Both wire elements 20, 20' are arranged in a helical shape on the circumference of the lattice structure 10.

According to the example 1 the wire element 20 reaches a full turn, in particular a turn of 360°, after a web 11, the turn comprising two adjacent webs 11. A different number of webs, for example one or three webs, is possible in order to achieve complete winding of the wire element 20 . In other words, the number of windings decreases the more webs are provided for a complete winding of the wire element 10 along the row of webs 14 .

The two sections 23a, 23a', 23b, 23b' of the wire elements 20, 20' intersect along the lattice structure 10 in a regular pattern. In concrete terms, the wire elements 20, 20' intersect at a plurality of crossing points 25, with the example according to FIG 1 three webs are arranged between two crossing points 25 along a row of webs 14 . A different number of bars, for example two bars or more than three bars, is possible.

At the proximal end section 10a, the wire elements 20, 20' end with free wire ends 24, 24', which are not fed back into the lattice structure 10 but are attached to the outer edge of the lattice structure 10. For this purpose, the lattice structure 10 has a plurality of bar extensions 16, specifically two bar extensions 16, which form the outermost region of the lattice structure 10 in the proximal direction. The free wire ends 24, 24' are guided up to the web extensions 16 and are connected to them there in the manner described below.

In 3 the distal end of the transport wire 40 is shown, on which a coupling piece 41 is located. The coupling piece 41 has the function of firmly connecting the lattice structure 10 to the transport wire 40 so that the lattice structure 10 can be released from the catheter for treatment and retracted again after the thrombectomy. For this purpose, the coupling piece 41 has a recess 42 which extends transversely to the longitudinal axis of the transport wire 40 .

As in the intermediate assembly step according to 4 As can be seen, the web extension 16 of the lattice structure 10 has an engagement element 16 which engages in the recess 42 with a precise fit. This creates a positive connection that is strong enough to transfer the forces that occur.

A crimp sleeve 30 is pushed over the form-fitting connection, 4 shown semi-transparent to reinforce and complete the positive connection.

5 shows a further assembly state of the connection, in which the free wire ends 24, 24' are passed through the crimp sleeve 30. The free wire ends 24 , 24 ′ are guided through an intermediate space which is formed between the crimp sleeve 30 and the web extension 16 of the lattice structure 10 . The web extension 16 can be profiled in the longitudinal direction of the transport wire in such a way that the wire ends 24, 24' are guided in a specific position, in particular parallel to one another, in the crimp sleeve 30. The crimp sleeve 30 holds the wire ends 24, 24' in position in the area of the coupling piece 41 so that the wire ends 24, 24' can be fixed with adhesive.

The free wire ends 24, 24' are approximately flush with the crimp sleeve 30, but may project slightly in the proximal direction.

According to the example 6 a coil 50 is pushed over the free wire ends 24, 24'. The coil 50 is filled with glue.

As an alternative to the Coil 50, as in 7 shown, the free wire ends 24, 24' protruding in the proximal direction beyond the crimp sleeve 30 can only be fastened with adhesive between the crimp sleeve 30 and the coupling piece 41 and the transport wire 40. A flattened variation of the crimp sleeve 30 for a better form fit can be seen here. The bond 43 tapers in the proximal direction from the crimp sleeve 30 in the direction of the transport wire 40 and is flush with the latter. Adhesive escapes at the distal end of the crimp sleeve 30, at which the wire ends 24, 24' are inserted. This shows that the wire ends 24, 24' are also glued inside the crimp sleeve 30.

Claims (17)

Medical device for intravascular treatment with an at least partially tubular lattice structure (10) made of webs (11) connected to one another in one piece and delimiting cells (12), four webs (11) being connected to one another by a web connector (13) and at least one x-ray visible wire element (20, 20') is provided, which is guided along at least one web (11) and in an end section (10b) of the lattice structure (10) a loop (21, 21') with a first leg (22a, 22a') and forms a second leg (22b, 22b'), the loop (21, 21') dividing the wire element (20, 20') into a first section (23a, 23a') and a second section (23b, 23b'), wherein the first section (23a, 23a') and/or the second section (23b, 23b') winds around a plurality of webs (11) which each form a row of webs (14) in alignment with one another, and the row of webs (14) being helical runs through it around a longitudinal axis of the lattice structure (10). characterized in that the first leg (22a, 22a') and the second leg (22b, 22b') radially inside the lattice structure (10) or the first leg (22a, 22a') and the second leg (22b, 22b') radially are arranged outside of the lattice structure (10). Medical device behind claim 1 , characterized in that the end portion (10b) is a distal end portion (10b). Medical device behind claim 1 and 2 , characterized in that the loop (21, 21 ') in an expanded state of the lattice structure (10) between two circumferentially adjacent distal end cells (12a, 12b) of the lattice structure (10) or within a distal end cell (12a, 12b) of Lattice structure (10) is arranged. Medical device according to one of the preceding claims, characterized in that the first leg (22a, 22a') and the second leg (22b, 22b') each pass through one of the end cells (12a, 12b). Medical device according to one of the preceding claims, characterized in that the loop (21, 21') in an expanded state of the lattice structure (10) from a distal web connector (13b) of the lattice structure (10) in the distal direction, in particular by at least one web width , preferably by at least 25% of a web length, more preferably by at least 50% of a web length, is arranged spaced apart. Medical device behind claim 5 , characterized in that the wire element (20, 20') is wound around a row of bars (14) in such a way that the wire element (20, 20') makes a full turn, in particular a turn of 360°, along the row of bars (14). a web (11), in particular after two webs (11), in particular after three webs (11). Medical device according to one of the preceding claims, characterized in that the wire element (20, 20') is formed by a completely radiopaque wire or a composite wire with a radiopaque core. Medical device according to one of the preceding claims, characterized in that two, three or four wire elements (20, 20') are provided, each forming a loop (21, 21') in the distal end section (10b) of the lattice structure (10). Medical device behind claim 8 , characterized in that the sections (23a, 23a', 23b, 23b') of the wire elements (20, 20') intersect regularly along the lattice structure (10), with at least two, in particular at least three, between two crossing points (25). , and at most eight, in particular at most six, webs (11) of a web row (14) are arranged. Medical device according to one of the preceding claims, characterized in that at most four loops (21, 21') each with a first leg (22a, 22a') and a second leg (22b, 22b') in a distal end section (10b) of Lattice structure (10) are arranged, wherein the first limb (22a') and the second limb (22b') are arranged radially inside or the first limb (22a') and the second limb (22b') are arranged radially outside of the lattice structure (10). . Medical device according to one of the preceding claims, characterized in that the lattice structure has at least one web extension (16) on a proximal end section (10a) which is positively connected to a distal coupling piece (41) of a transport wire (40). Medical device behind claim 11 , characterized in that the web extension (16) has an engagement element (16a) which fits exactly into a recess (42) of the coupling piece (41) which extends transversely to a longitudinal axis of the transport wire (40). Medical device behind claim 11 or 12 , characterized in that a crimp sleeve (30) is provided, which surrounds the web extension (16) and the coupling piece (41). Medical device behind Claim 13 , characterized in that the wire element (20, 20') is passed through the crimping sleeve (30), the wire end (24, 24') terminating approximately flush with the crimping sleeve and/or protruding slightly proximally beyond the crimping sleeve (30). . Medical device behind Claim 14 , characterized in that the wire protruding end (24, 24') is connected to the transport wire (40) by an adhesive-filled coil (50), the coil (50) connecting the wire protruding end (20, 20') and the transport wire (40) encloses. Medical device behind Claim 13 or 14 , characterized in that the crimp sleeve (30) and the protruding wire end (24, 24') are glued directly to the transport wire (40). Method of manufacturing a medical device claim 1 , wherein at least one wire element (20, 20'), in particular a loop (21, 21') of the wire element (20, 20') is heat-treated, so that the wire element (20, 20'), in particular the loop (21, 21 ') in the expanded state, in particular in the partially expanded state, is largely stress-free.

Images