WO2010000475A1

WO2010000475A1 - Filter for a blood vessel, and treatment system with such a filter

Info

Publication number: WO2010000475A1
Application number: PCT/EP2009/004795
Authority: WO
Inventors: Kirsi SCHÜSSLER
Original assignee: Acandis Gmbh & Co. Kg
Priority date: 2008-07-02
Filing date: 2009-07-02
Publication date: 2010-01-07
Also published as: DE102008031299B4; DE102008031299A1

Abstract

The invention relates to a filter (1) for a blood vessel, with a holding portion (10) which is designed to fix the filter (1) on a vessel wall, and with a filter portion (11) which is connected to the holding portion (10) and, in the implanted state, covers the cross section of the blood vessel at least in part. The invention is characterized in that the filter portion (11) can move radially outwards from a closure position, in which the filter portion (11) covers the cross section of the blood vessel at least in part, to an open position in which the filter portion (11) bears on the vessel wall at least in part and frees the cross section of the blood vessel, wherein the filter portion (11) has a closure element (12) that keeps the filter portion (11) closed in the closure position and can be actuated in order to open the filter portion (11). The invention further relates to a treatment system with such a filter (1).

Description

Filter for a blood vessel and treatment system with such a filter

description

The invention relates to a filter for a blood vessel with the features of the preamble of claim 1 and a treatment system with such a filter. A filter of this type is known, for example, from WO 2007/047818 A1. This is an invertible protective filter for plaque, which is held with one end in a catheter. The other end of the filter is connected to control wires that are operable by the operator. By the control wires, the free end of the filter is folded in the proximal direction, so that a concave filter bag is formed, is trapped in the plaque located in the blood. For this purpose, the outer diameter of the filter is adjusted by means of the control wires so that it rests against the vessel wall. When the pocket of the filter is filled with plaque particles, it is removed through the catheter along with the plaque trapped therein.

The known filter thus has the advantage that it only temporarily performs a filter function as long as the plaque to be filtered is located in the blood. Thereafter, the filter is completely removed from the body. The bag-shaped design of the filter carries the risk that it is not held back plaque safely, but can get back into the bloodstream when removing the filter. In addition, the control of the filter by means of the wires is expensive.

The invention has for its object to provide a filter for a blood vessel, which is simple and allows a temporary filter function. It also exists the objects of the invention is to provide a treatment system with such a filter.

According to the invention this object is achieved by a filter having the features of claim 1. With regard to the treatment system, the object is achieved by the subject matter of claim 16.

The invention is based on the idea of providing a filter for a blood vessel which has a holding section for fixing the filter to a vessel wall. The filter further has a filter section which is connected to the holding section and in the implanted state at least partially covers the cross section of the blood vessel. The filter section can be moved radially outwardly into an open position from a closed position, in which the filter section at least partially covers the cross-section of the blood vessel. In the open position, the filter section is at least partially on the vessel wall or is adapted to abut in regions on the vessel wall, and releases the cross section of the blood vessel. The filter section has a closure element which holds the filter section closed in the closed position and can be actuated to open the filter section.

The invention has the advantage that the filter is designed so that its filter function is temporarily controllable. This means that the filter function can be selectively terminated when it is no longer needed, for example, when no more plaque in the blood is removed. In contrast to the generic known filter filter of the invention does not have to be removed from the body, but can remain in this, when its filter function is completed. For this purpose, it is provided that the filter section is movable from a closed position into an open position, the filter section in the closed position at least partially covering the cross section of the blood vessel. In the open position of the filter section is adapted so that it rests at least partially on the vessel wall and the cross section of the blood vessel releases. In order to move from the closed position to the open position, the filter section is movable radially outward. This is achieved in a simple and effective manner that the filter can assume two different states, namely a filter state (closed position) and an open state (open position). The targeted transfer of the filter from the filter state to the on state is achieved by the closure element, which keeps the filter section closed in the closed position. To open the filter section, ie for transferring the filter section into the open position, the closure element can be actuated. As a result, the filter section is released and moved radially outward into the open position.

The combination of the radially outwardly movable filter section together with the closure element allows a structurally simple to implement filter function, which is activated after a certain time, ie with a time delay.

Preferably, the filter section is acted upon in the closed position with a radially outwardly acting biasing force such that the filter section is movable by actuation of the closure element in the open position. By acting radially outward biasing force required for the movement of the filter section in the open position drive is effected in a simple manner.

The filter section may be umbrella-like, in particular with a concave or convex curvature, which is advantageous in terms of the filter function on the one hand and on the other hand with regard to the transfer of the filter section from the closed position to the open position.

The filter section has, in a preferred embodiment, a plurality of filter segments, which are connected on the one hand to the closure element and on the other hand to the holding section. The filter segments are movable relative to each other in this embodiment for opening the filter section. This ensures that an associated with the opening movement diameter change of the filter section is effected.

The filter section may be arranged coaxially with the holding section, thereby enabling easy placement of the filter. The filter section can also be arranged at a proximal or at a distal end of the holding section or in the region between the proximal and the distal end, whereby various design options for the filter section are opened. For example, the filter section convexly formed in the direction of flow at the proximal end or the filter section concave in the flow direction can be arranged or connected to the distal end of the holding section. It is also possible that the Filter section in a central region, in particular centrally, between the proximal and the distal end is arranged or connected.

In a further preferred embodiment, the closure element has an opening for a guide wire, so that the filter can be easily placed in the blood vessel. The opening of the closure element can be closed by a hinged membrane, which expediently prevents plaque from entering the bloodstream through the opening of the closure element.

The closure element may be formed of a biodegradable material, so that after a material-dependent, predetermined time value, the closure element is decomposed and releases the filter section. This results in an automatic transfer of the filter section from the closed position to the open position. The closure element may comprise a micromechanical switch which can be actuated by electromagnetic waves. In this way, the closure element can be operated from outside to open the filter section (remote control). The closure element can be actuated mechanically, in particular by a guide wire or by a catheter-compatible opening tool. The mechanically actuated closure element is simple.

The filter section may have a filter membrane of a degradable material, so that the possibility exists that the filter or individual filter parts decompose in the open position, so that the filter is then completely degraded by the body.

The filter can form a self-contained unit. This means that the filter is not connected to any other medical devices, but can be handled as a separate unit. The filter can be connected to a stent or to a balloon, so that the temporary filter effect can be used in conjunction with other medical implants or devices.

According to a secondary aspect, the invention is based on the idea of specifying a treatment system comprising a filter described in the introduction and a catheter shaft having a proximal longitudinal end and a distal longitudinal end which can be positioned in a blood vessel. In this case, the filter is arranged axially displaceably in the catheter shaft. The filter section of the filter has a proximal male tip, which is arranged in the direction of the proximal longitudinal end of the catheter shaft. The tip of the filter section, in particular the closure element, thus points or points in the direction of the proximal longitudinal end of the catheter shaft.

This arrangement of the filter section or proximal tip in the catheter shaft or catheter has the advantage that the filter section in use, i. after discharge from the distal longitudinal end of the catheter, can be converted into the open position such that the filter section opens in the direction of the catheter or the proximal longitudinal end of the catheter. In this way, thrombus particles which are arranged, in particular captured, in the closed position of the filter section between the tip arranged centrally in the blood vessel and the vessel wall, are pressed against the vessel wall during opening of the filter section and fixed to the vessel wall through the opened filter section.

Preferably, in the closed position, the filter section has a distally located, annular base connected to a proximal end or a distal end of the retaining section. By the connection of the annular base with the proximal or distal end of the holding portion advantageously a particularly simple and secure placement of the filter is achieved in a blood vessel. This applies in particular to the arrangement of the annular base at the proximal end of the holding element. In this case, when the filter is released from the catheter, first the holding section is clamped, so that an initial fixation in the blood vessel is ensured.

Conveniently, the closure element forms the tip of the filter section. In use, the filter is thus advantageously arranged in the blood vessel such that the proximal tip or the closure element is directed against the blood flow. The filter section is thus preferably arranged like a flow divider or keel-like against the blood flow. It is not precluded that the filter is arranged in the catheter shaft or the catheter line, which is positioned in a blood vessel, that the proximal tip or the closure element is shown or arranged substantially in the opposite direction to the main flow direction of the blood flowing around the catheter shaft. That is, in use, the annular base is disposed downstream of the proximal tip or closure element, in particular downstream of the proximal tip and the closure element, respectively. This arrangement of the filter in the blood vessel or in the catheter line is also claimed in the context of the application. In a preferred embodiment of the treatment system according to the invention, a stent, in particular Stenosestent, provided, which is arranged proximal to the filter and connected to the filter section, in particular with the annular base, and / or the holding portion or connectable. In this case, the filter section is advantageously arranged axially between the stent and the holding section. The stent may further include connecting arms connecting the stent to the annular base of the filter section.

In the context of the application, the directional designations "proximal" and "distal" generally refer to the spatial arrangement in relation to the user of the filter or treatment system. This means that components which are arranged distally are arranged farther away from the user in the intended use of the filter or treatment system than components arranged proximally. With respect to the treatment system, the user-removed, proximal, longitudinal end of the catheter shaft is disposed within a blood vessel in use, with the catheter shaft preferably connected to the blood flow, i. is aligned with the blood flow, is placed. Thus, the blood preferably flows from a proximal portion of the catheter shaft toward the distal longitudinal end of the catheter shaft.

The invention will be explained in more detail by means of embodiments with reference to the accompanying schematic drawings.

In these show:

Fig. Ia a filter according to an embodiment of the invention in the

Closed position;

FIG. 1b shows the filter according to FIG. 1a in the open position; FIG.

Ic shows a detailed view of the filter according to Fig. Ia;

Fig. Id is a detail view of a filter according to another embodiment; Ie is a plan view of the filter according to the figures Ic, Id in the flow direction and in the closed position.

2a shows a filter according to an embodiment of the invention in connection with a balloon;

FIG. 2b shows the filter according to FIG. 2a in the open position and in the closed position; FIG.

Fig. 3a shows a filter according to another embodiment of the present invention connected to a partially expanded stent located in a catheter;

FIG. 3b shows the filter according to FIG. 3a with expanded stent; FIG.

Fig. 3c, the filter of FIG. 3b in the open position.

In Fig. 1, an embodiment of a filter 1 according to the invention is shown, which is arranged in a blood vessel. The filter 1 shown in Fig. Ia is in the closed position and filters in the blood vessel plaque particles 6, which move in the flow direction (arrow S). The filter 1 comprises a holding portion 10, which forms a retaining ring in the embodiment according to FIG. The retaining ring is constructed or structured similar to a short stent. The holding portion 10 is adapted to and serves to fix the filter in the implanted state on the vessel wall 5 of the blood vessel.

The holding section 10 is connected to a filter section 11. The filter section 11 comprises a porous filter membrane with openings between about 50 microns and 100 microns, depending on the conditions of use, other opening diameter or a different porosity of the filter membrane are possible. The filter membrane may be formed, for example, as a polyurethane membrane or as Dünnfilmnitinilmembran. Other materials are possible. The filter membrane and / or other filter parts, or generally the filter section 11 may be constructed of a degradable material, so that the deactivated filter is completely or at least almost completely degraded by the body when it is no longer needed. The filter section 11 covers in the closed position the cross section of the blood vessel, as shown in Fig. Ia to recognize. The filter section 11 extends away from the holding section 10 in the proximal direction, ie counter to the flow direction of the blood, forming a screen-like curvature 13. The filter section 11 is arranged coaxially to the holding section 10. A decentralized arrangement of the filter section 11 with respect to the holding section 10 or with respect to the central axis of the blood vessel is possible. In the embodiment according to FIG. 1 a, the filter section 11 is arranged at a proximal end 10 a of the holding section 10. Another arrangement or connection of the filter section 11 with the holding section 10 is possible and will be explained in more detail in connection with Fig. Id.

The filter section 10 has a closure element 12 which is integrated in the filter section 11. The closure element 12 is adapted to keep the filter section 11 closed in the closed position. To open the filter section 11, the closure element 12 can be actuated. In this case, the filter section 11 is adapted so that it can be transferred from a closed position to an open position. In the closed position, which is shown in FIG. 1 a, the filter section covers the cross section of the blood vessel at least in regions. The filter section 11 is further adapted so that it is movable radially outward into the open position. The opening movement of the filter section is shown by the arrow O in Fig. Ia.

The open position of the filter 1 is shown in Fig. Ib. It can be seen that the filter section 11 in the open position substantially abuts against the vessel wall 5 and thereby releases the cross section of the blood vessel. That is, in the open position, the filter portion 11 is disposed substantially on an imaginary cylindrical circumference, with the end faces of the imaginary cylinder forming the opened filter passage. It is also possible for the filter section 11 to occupy a different degree of open position, wherein, for example, the filter section does not bear directly on the vessel wall, but still somewhat protrudes into the blood vessel, for example on the imaginary circumference of a truncated cone. An advantage of the invention, which is achieved by the concern of the filter section 10 on the vessel wall, is that in the closed position shown in Fig. Ia retained by the filter 1 plaque particles in the open position shown in FIG. Ib between the filter section 11 and the Vessel wall 5 are included. This ensures that the plaque particles do not enter the bloodstream when the filter function is deactivated. The figures Ic, Id show two different ways in which the filter section 11 can be designed. According to FIG. 1c, the filter section 11 forms a convex curvature 13 projecting in the flow direction S. The filter section 11 is fastened to the proximal end 10a of the retaining element 10.

In the exemplary embodiment according to FIG. 1 d, the filter section 11 forms a curvature 13 which projects concavely in the flow direction S. The filter section 11 is in this case connected to the distal end 10 b of the retaining element 10.

In both cases, the filter section 11 is acted upon by a radially outwardly acting biasing force. By releasing the closure element 12 holding the filter section 11 in the closed position, the radially outwardly acting biasing force causes a movement of the filter section 11 in the direction of the arrow O radially outwardly into the open position. In this case, trapped by the filter 1 plaque between the vessel wall 5 and the filter section 11 is clamped or retained.

The movability of the filter section 11 radially outwards means that at least part of the filter section 11 moves from the interior of the vessel in the direction of the vessel wall during the transfer to the open position. This is the case, for example, in the part of the filter section 11, which cooperates with the closure element 12 in the closed position and is released after the closure element 12 has been actuated. At least this part of the filter section 11 moves outwardly towards the vessel wall by the biasing force. The term "radially outward" is therefore to be interpreted very broadly For example, it is also possible to design the filter or the filter section like a cover, wherein the filter is movably, in particular foldably, connected to the holding section at a circumferential location In the open position, the filter is folded against the vessel wall and releases the blood vessel The point of the lid-like filter section arranged opposite the connection or articulation point between the filter section and the holding section describes during the transfer from the closed position into the open position a movement radially outward, ie, a movement of the one vessel wall to the opposite vessel wall, where the filter portion in the open position is applied. One way in which the radially outward opening movement of the filter section 11 and the associated enlargement of the filter diameter or the formation of the passage is achieved is illustrated in FIG. 1e. There, it can be seen that the filter section 11 comprises a plurality of filter segments 14, which are connected on the one hand to the closure element 12 and on the other hand to the holding section 10. The filter segments 14 have interfaces 14a on which the individual filter segments 14 are not connected to one another laterally. Through the interfaces 14a it is achieved that the filter segments for opening the filter section 11 are movable relative to each other. Other arrangements of the filter segments 14 are possible. For example, the filter segments 14 may be connected to each other by flexible film members that span the perimeter of the filter section 14 in the open position such that the opened filter section 11 or filter segments together with the flexible interleaf films form a closed cylindrical shell adjacent the vessel wall continuous. The filter segments 14 are similar to diaphragm blades formed and each have a radially inwardly tapered shape.

As can be seen in FIG. 1e, the radially inner end of the individual segments 14 is connected to the closure element 12. The other end of the filter segments 14 a is connected to the holding element 10. Further, in Fig. Ie, the filter openings 14 b are shown, which are provided in the formed as a porous filter membrane film of the filter section 11.

The filter elements, in particular the filter membrane may be coated with antithrombogenic substances and / or release antithrombogenic drugs. The filter elements and / or the filter membrane can be constructed from biodegradable materials, in particular biodegradable plastics or thin-film films based on magnesium or iron.

The closure element 12 has an opening 15, which is adapted so that the filter can be placed using a guide wire or a guide wire 16 can be passed therethrough. The opening 15 may be closed with a hinged membrane (not shown) so that no plaque particles can pass through the opening after removal of the guidewire. In the exemplary embodiment according to FIGS. 1 a to 1 e, the closure element 12 is designed as a mechanically actuable closure element 12. For actuating the closure element 12 the guidewire 16 (not shown in FIGS. 1a to 1e) is used which, by suitable movement, releases the closure element 12 from the filter segments 14a so that the filter section 14 is released. Due to the bias of the individual filter segments 14a and the filter section 14, this moves in the open position. Other ways to realize the actuatable closure element 12 include a micromechanical switch which is actuatable by electromagnetic waves and releases the filter segments 14a. It is also possible to effect the actuation of the filter element 12 in that the closure element 12 is made of a biodegradable material which dissolves after a certain time and also releases the filter segments 14a.

In Fig. 2a, a further application of the filter according to FIG. 1 is shown. The filter is combined with a balloon catheter. Specifically, the filter is connected during balloon dilatation with the balloon catheter, in particular with the catheter shaft 19. Any plaque particles that become detached during dilation are collected by the filter 1. After dilation, the balloon 18 is removed and the filter 1 remains in the vessel. In this case, the filter section 11 works in the manner described above radially outward and is, as shown schematically in Fig. 2b, on the vessel wall.

In a further embodiment, the filter is combined with a stent, in particular firmly connected to the stent. This embodiment is shown in Figures 3a, 3b and 3c. The filter-stent arrangement or the filter-stent combination is particularly advantageous when placing a stent, since most plaque particles enter the bloodstream when the stent is released into the blood vessel. This means that the filter function is required only for a relatively short period of time. In the prior art, therefore, so-called stenting, in particular in the carotid artery, is usually preceded by the so-called distal protection filter before the actual stent procedure. The advantage of the combination of stent and filter is that the placement of the stent and the filter are combined in one step, thus saving time and money. The deactivated after use filter then behaves like an extension of the actual stent, so that his stay in the vessel does not bother.

The filter is arranged at the distal end of the system or the stent 17 and firmly connected thereto. The connection between the stent and the filter takes place by connecting arms 20. The stent-filter combination comprising the stent 17 and the filter 1 is placed in the vessel by means of a catheter (in Fig. 3a the catheter shaft 19 is shown), wherein the filter 1 is already expanded in the vessel before the stent 17 begins to expand (Figure 3a). It can also be seen in FIG. 3 a that the guide wire 16 is passed through the closure element 12. The connecting arms 20 are adapted and in particular so long that the filter when releasing the filter-stent combination first fully expands and covers the blood vessel before the stent is released. This ensures that the plaque particles which are released during (subsequent in time) setting of the stent are retained by the filter.

In Fig. 3b it is shown that the stent 17 and the filter 1 are opened in the blood vessel, wherein plaque particles are filtered by the filter 1. In Fig. 3b, the connection between the filter 1 and the stent 17 by means of the connecting arms 20 is clearly visible. The filter 1 according to FIG. 3 is in the closed position. By actuating the closure element 12, for example by retracting the guide wire 16, the closure element 12 is removed or manipulated such that the filter section 11 or the filter segments 14a are released. For this purpose, the guide wire 16 may be profiled so that this cooperates when retracted by the closure element with this accordingly. As a result of the prestressing of the filter section 11, it is moved radially outward after actuation of the closure element 12 (FIG. 3c). In this case, the filter section 11 is arranged above the connecting arms 20 and includes the intercepted with the filter 1 plaque particles with the vessel wall 5 a.

For positioning the filter 1 in a blood vessel, a treatment system is provided, which comprises a catheter or a catheter shaft 19, in which the filter is arranged axially displaceable. The arrangement of the filter 1 in the catheter substantially corresponds to the arrangement of the filter 1 in the blood vessel according to the figures Ic, Id, 2b and 3b. In this case, the vessel wall 5 corresponds to the catheter wall or the inner wall of the catheter shaft 19. FIG. 3 a shows how the filter 1 is advantageously released from the catheter shaft 19.

With reference to Figures 2b and 3b, the arrangement of the filter 1 in a catheter shaft 19 and in a catheter line is explained in more detail below. In this case, the axially aligned arrows shown in FIGS. 2b and 3b describe the direction from the proximal longitudinal end 19a of the catheter or catheter shaft 19 to the distal longitudinal end 19b of the catheter shaft 19.

The filter section 11 in this case has a proximal tip 21a, which faces the proximal longitudinal end 19a of the catheter or points in the direction of the proximal longitudinal end 19a of the catheter. The proximal tip 21 a comprises the closure element 12. Concretely, the proximal tip 21 a is formed by the closure element 12. In a cross-sectional plane of the filter portion 11, which is arranged parallel spaced from a cross-sectional plane including the proximal tip 21a, the filter portion 11 has an annular base 21b. The annular base 21b essentially forms a conical base surface of the filter section 11 which is tapered in the closed position. The geometry of the filter section 11 is not limited to a conical shape with straight generatrices. Rather, the generatrices of the conical filter portion 11 may also have a curvature, so that the filter portion 11 forms a total curvature. Preferably, the bulge is oriented toward the proximal longitudinal end 19a of the catheter or catheter shaft 19. This means that the filter section 11 bulges substantially in the direction of the proximal longitudinal end 19a of the catheter shaft 19, the proximal tip 21a forming the center or the extreme point of the curvature. Alternatively, the filter section 11 can also have two or more curved regions in the direction of the distal longitudinal end 19b of the catheter, which curve towards the proximal tip 21a such that the filter section 11 has an arrow-like longitudinal profile pointing in the direction of the proximal longitudinal end 19a of the catheter ( Fig. Id).

The annular base 21 b is connected to a proximal end 10 a of the holding portion 10. Alternatively, the annular base 21b may also be connected to a distal end 10b of the holding portion 10, as shown for example in Fig. Id. In general, the annular base 21b in use, that is arranged in a blood vessel, downstream of the proximal tip 21a, in particular the closure element 12, in the flow direction. The filter section 11 thus essentially forms a longitudinal section profile which extends in a wedge-shaped or bug-shaped manner into the blood flow. The blood flow is thus deflected by the filter section 11 partially in the direction of the vessel wall 5, in particular radially outward.

Overall, the filter section 11 has a substantially cone-like shape, wherein the conical lateral surface in longitudinal section, specifically the conical surface line, not imperatively forms a straight-line connection between the annular base 21b and the tip 21a and the closure element 12. Rather, the conical surface line may also have a concave or convex curvature. It is expedient if the filter section 11 has a total of a rotationally symmetrical structure. In this case, the annular base 21b forms the base surface of the cone-like or hollow cone-like filter section 11. It is not excluded that the filter section 11 also has another cross-sectional geometry that is different from a circular shape. For example, the annular base 21b may be formed substantially polygonal or polygonal.

The invention is not limited to the above-described combination options, but also includes all other combinations in which the temporarily closed filter is combined with other implants.

LIST OF REFERENCE NUMERALS

1 filter

5 vessel wall

10 holding section

10a proximal end

10b distal end

11 filter section

12 closure element

13 vaulting

14 filter segments

15 opening

16 guide wire

17 stents

18 balloon

19 catheter shaft

19a proximal longitudinal end

19b distal longitudinal end

20 connecting arms

21a proximal tip

21b annular base

Claims

claims

A filter (1) for a blood vessel having a holding portion (10) adapted to fix the filter (1) to a vessel wall and a filter portion (11) connected to the holding portion (10) and in the implanted state covers the cross-section of the blood vessel at least in regions such that the filter section (11) can be moved radially outward from a closed position in which the filter section (11) covers the cross-section of the blood vessel in an open position the filter section (11) bears against the vessel wall at least in regions and releases the cross section of the blood vessel, the filter section (11) having a closure element (12) which keeps the filter section (11) closed in the closed position and for opening the filter section (11 ) is operable.

2. Filter according to claim 1, characterized in that the filter section (11) in the closed position is acted upon by a radially outwardly acting biasing force such that the filter section (11) is actuated by actuation of the closure element (12 ) is movable in the open position.

3. Filter according to claim 1 or 2, dad u rch geken nzeich net that the filter section (11) umbrella-like, in particular with a concave or convex curvature (13) is formed.

4. Filter according to at least one of claims 1 to 3, d ad u rch geken nzeich net, that the filter section (11) comprises a plurality of filter segments (14) connected on the one hand with the closure element (12) and on the other hand with the holding portion (10) are, wherein the filter segments (14) for opening the filter section (11) are movable relative to each other.

5. Filter according to at least one of claims 1 to 4, dadu rch geken nzeich net, that the filter section (11) is arranged coaxially to the holding portion (10).

6. Filter according to at least one of claims 1 to 5, characterized in that the filter section (11) at a proximal or at a distal end (10a, 10b) of the holding portion (10) or in the region between the proximal and the distal end (10a, 10b).

7. Filter according to at least one of claims 1 to 6, characterized in that the closure element (12) has an opening (15) for a guide wire (16).

8. The filter according to claim 7, characterized in that the opening (15) can be closed by a hinged membrane.

9. Filter according to at least one of claims 1 to 7, characterized in that the sealing element (12) is formed from a biodegradable material.

10. The filter according to claim 1, characterized in that the closure element (12) comprises a micromechanical switch which can be actuated by electromagnetic waves.

11. Filter according to claim 1, characterized in that the closure element (12) can be actuated mechanically, in particular by a guide wire (16) or by a catheter-capable opening tool.

12. Filter according to at least one of claims 1 to 11, characterized in that the filter section (11) has a filter membrane made of a degradable material. fabric.

13. The filter according to claim 1, characterized in that the filter (1) forms a closed unit.

14. Filter according to at least one of claims 1 to 12, characterized in that the filter (1) is connected to a stent (17).

15. The filter according to claim 1, wherein the filter is connected to a balloon.

A treatment system comprising a filter (1) according to any one of claims 1 to 18 and a catheter shaft (19) having a proximal longitudinal end (19a) and a distal longitudinal end (19b) positionable in a blood vessel, the filter (1 ) is axially displaceable in the catheter shaft (19) and the filter section (11) has a proximal tip (21a), in particular the closure element (12), which is arranged in the direction of the proximal longitudinal end (19a) of the catheter shaft (19).

17. Treatment system according to claim 16, characterized in that in the closed position the filter section (10) has a distally arranged, annular base (21b) which is connected to a proximal end (10a) or a distal end (10b). the holding portion (10) is connected.

18. A treatment system according to claim 16 or 17, g eken nzei ch n et by a stent (17), in particular Stenosestent, the proximal to the filter (1) arranged and with the filter section (11), in particular the annular base (21 b), and / or the holding portion (10) is connected or connectable.