WO2010115642A1

WO2010115642A1 - Device for removing concretions from body vessels

Info

Publication number: WO2010115642A1
Application number: PCT/EP2010/002230
Authority: WO
Inventors: Giorgio Cattaneo; Michael BÜCHERT
Original assignee: Acandis Gmbh & Co. Kg
Priority date: 2009-04-09
Filing date: 2010-04-09
Publication date: 2010-10-14
Also published as: DE102009017050B4; EP2416715A1; DE102009017050A1

Abstract

The invention relates to a device for removing concretions from body vessels, with a tube-shaped compressible catcher element (100), which can be converted from a state with a relatively larger cross-sectional diameter to a state with a relatively smaller cross-sectional diameter under the influence of an external force. The invention is characterised in that the catcher element (100) has an inlet region (130), which extends in the longitudinal direction between a distal filter region (150) and a proximal holding region (110) and comprises webs (135) arranged on a lateral cylinder surface, which webs are spaced apart in the circumferential direction and delimit the entry openings (140). The holding region (110) has a fluid-tight, flexible cover (115) that forms a cavity (120), which can be closed off by the concretion to be removed, within the holding region (110) during use, which cavity is operatively connected to a pressure generation arrangement such that a different pressure than outside of the cavity (120) can be set inside the cavity (120) for moving, more particularly removing, the concretion to be removed.

Description

Device for removing concrements from body vessels

description

The invention relates to a device for removing concrements from body vessels according to the preamble of claim 1 and to an apparatus for removing concrements from body vessels according to the preamble of claim 15. Such a device is known for example from WO 2006/031410.

The formation of concrements in body vessels can lead to the body vessel being completely or at least partially closed by the concrement, with the consequence of considerable health restrictions. A particularly high risk is assumed by thrombi, i. Blood clots that form intravascularly and may partially or completely occlude the blood vessel. When the occlusion concerns an artery, the downstream tissue areas are no longer or inadequately supplied with oxygen and other nutrients, termed ischemia, potentially resulting in tissue death.

Currently, thrombi in human arteries are usually treated by drug thrombolysis, whereby the blood clots are dissolved by means of drugs. The condition for this therapy is that the treatment takes place no later than three hours after the appearance of the symptomatology. In addition to this narrow time window, drug thrombolysis has the disadvantage that the treatment is not only local in the area of the thrombus, but on the entire cardiovascular system. By inhibiting blood clotting there is a risk of bleeding complications, for example, the risk that the therapy causes cerebral hemorrhage.

An alternative to drug therapy is the mechanical removal of thrombi from blood vessels, as proposed in the aforementioned WO 2006/031410 Al. Therein is disclosed a device comprising a receiving basket having a stent-like lattice structure for insertion into the blood vessel in a compressed state within a Catheter is arranged. To remove the blood clot, the catheter is inserted into the blood vessel until the catheter tip is positioned near the thrombus. The receiving basket located in the catheter is released at the catheter tip and unfolds there to about the size of the vessel diameter, so that the thrombus can be taken up by the basket. The catheter is also designed as an aspiration catheter, which generates a negative pressure in the area in front of the thrombus, so that parts of the thrombus are detached and sucked into the catheter. The receiving basket additionally serves as a filter so that no larger particles are transported past the aspiration catheter into further blood vessels.

In the known device, a relatively large area is subjected to a negative pressure by the aspiration in the area in front of the thrombus. There is a risk that the pressure in parts of the cardiovascular system may drop below the level of physiological pressure until the transmural pressure becomes negative. This can result in the blood vessel in front of the thrombus narrowing or collapsing, so that the blood flow in this area is restricted or completely interrupted. This prevents efficient detachment of the thrombus on the one hand and risks the vessel being injured by the effect of the negative transmural pressure on the other hand. In particular, when the negative pressure in vessel areas with branching secondary vessels acts, there is a risk that the smaller side vessels collapse and thus previously well-perfused tissue areas are inferior. Even with positive transmural pressure, aspiration induces negative pressure, i. a pressure that is less than the physiological pressure, to a reduced blood flow to the affected areas, especially in smaller secondary vessels.

Another problem when using the known device results in cases when the thrombus to be solved does not close the entire vessel cross-section, so that still partially a blood flow is possible. Such a situation can arise, for example, in that parts of the thrombus have already been removed by the aspiration, so that the vessel is partially recanalized, ie reopened. There is a risk that the blood flowing past the catheter and through the receiving basket when passing through the thrombus entrains particles that can lead to a re-occlusion in downstream, smaller blood vessels. To counteract this process, it is known to increase the aspiration volume, so that the entire, flowing through the blood vessel blood is sucked. In this case, a large volume of blood is taken from the patient in a relatively short period of time, which can result in considerable health consequences. Particle detachment with subsequent closure of downstream vessels may occur, in particular, when a relatively large particle is released from the thrombus by aspiration, aspirated by the catheter, and the suction opening is thereby closed. In this case, the generation of the negative pressure is suddenly interrupted, so that the original pressure conditions in the blood vessel are restored. The re-forming blood flow can detach other particles and transport them to downstream vessels, which can lead to a renewed vascular occlusion.

The invention is based on the object to provide a device for removing concrements from body vessels, which ensures easy and safe handling and function and reduces the health risks to the patient.

According to the invention, this object is achieved by the subject matter of patent claim 1. Alternatively, the object is achieved by the subject matter of the independent patent claim 15.

The invention is based on the idea to provide a device for removing concrements from body vessels with a tubular, compressible catcher element, which can be converted under the influence of an external constraint of a state with a relatively larger cross-sectional diameter in a state with a relatively smaller cross-sectional diameter. The catcher element has an inlet region which extends in the longitudinal direction between a distal filter region and a proximal receiving region and comprises webs which are arranged on a cylinder jacket surface in a circumferentially spaced manner and which delimit inlet openings. The receiving area has a fluid-tight, flexible cover which, in use, within the receiving area forms a cavity which can be closed by the concretion to be removed. The cavity is operatively connected to a pressure generating device such that in the cavity for moving, in particular for releasing, the calculus to be removed, a different pressure is adjustable than outside the cavity.

The advantage of the invention is that with the catcher element according to the invention a concretion within a body vessel can be substantially enclosed or encapsulated, so that with the help of the pressure generating device in the concretion, ie in the treatment area, a pressure can be set, which differs from differs from the physiological pressure usually present in this area. In this case, both in relation to the usual physiological pressure increased pressure (overpressure), as well as a comparatively smaller pressure (negative pressure) are generated. As a result of the generation of pressure, the calculus is subjected to a force which leads to detachment of the concretion from the vessel wall. This detachment force is generated essentially by the pressure difference on both sides of the concretion, since the concretion preferably limits the cavity in which the other pressure is adjusted. This means, in particular, that acts on the pressure generating unit facing side of the concretion of the set pressure, whereas on the side facing away from the pressure generating unit side of the concretion substantially the usual, physiological pressure acts.

Appropriately, to release the concretion, in particular for sucking the concretion in the receiving portion of the catcher element, a negative pressure generated proximal of the concretion by the pressure generating unit. It is also conceivable that at least temporarily or temporarily in the proximal cavity, which is formed by the receiving portion of the catcher element and the calculus, an overpressure is generated, so that the calculus with a directed away from the pressure generating unit, i. acting in the distal direction force component is applied. The generation of positive and negative pressure can also be performed oscillating to facilitate the detachment of the calculus.

In this context, it should be noted that the medical directional indications proximal and distal in the context of this application to the position of the user, in particular of the attending physician, relates, which operates the device. Proximally arranged components or objects are therefore arranged closer to the user or operator of the device with respect to a distally arranged component or object.

As a cavity in the context of the application generally spaces are referred to, which are formed by an interaction of the calculus to be removed with the catcher element, in particular the receiving portion of the catcher element, or the fluid-tight, flexible seal and are completed substantially free of installation and fluid-tight. The cavities in the sense of the application need not be completely closed on the concretion side. Cavities within the meaning of the application also include cavities which are at least partially delimited by a concrement, wherein the concrement does not completely but largely closes the cavity.

The webs described in the present application are not limited to individual, linearly arranged wire elements. Rather, the webs generally describe elongated elements, which may include, for example, crossed wire elements or wires. The wire elements may also have flat bands or laser-cut structures. The webs or generally elongate elements can also be structured in a wave-like manner, wherein the wave troughs and peaks can extend both in the circumferential direction and in the radial direction. Such a wave structure promotes the detachment of concrements.

In the context of the present application, the term pressure is not just a positive pressure (overpressure), but explicitly also a negative pressure (negative pressure). The overpressure or negative pressure refers to the prevailing in the vessel physiological pressure. Overpressures are therefore pressures that exceed the physiological pressure, whereas negative pressures fall below the physiological pressure. A negative pressure or negative pressure in the sense of the application is therefore present when the physiological pressure within the body vessel is reached. It is not excluded that the negative pressure has a positive value relative to the atmosphere, which, however, is below the value for the physiological pressure.

The invention is explained below with reference to the use for removing blood clots or thrombi from blood vessels. This purpose is to be understood as an example. Other possible uses of the device according to the invention, which generally relate to the removal of concrements or objects or foreign bodies from body cavities, are likewise encompassed and claimed by the invention.

The catcher element according to the invention is essentially subdivided into three contiguous areas, a receiving area, an inlet area and a filter area. The receiving area is proximal and the filter area is distally arranged. Between the receiving area and the filter area, the inlet area extends. By arranged on a cylinder surface in the circumferential direction spaced webs of the inlet region inlet openings are formed in the inlet region. The catcher element, which can be converted from a compressed state to an expanded state, can thus be positioned with the inlet region in the region of the concretion to be removed, so that upon expansion of the catcher element, the concretion to be removed passes through the inlet openings. The concretion or the thrombus to be removed is thus arranged in the interior of the catcher element, in particular in the inlet region. In this case, the webs of the inlet region can take on a cutting function, so that the thrombus is at least partially severed by the webs during expansion of the catcher element. The detachment of the thrombus is thus facilitated. It is also possible that Promote detachment of the thrombus or calculus in that the catcher element is rotated or rotated in use or in a released state with simultaneous aspiration or pressure generation in the cavity, so that the webs the thrombus intersecting along the vessel wall.

The distal filter region of the catcher element prevents detachment of elements or particles detaching from the thrombus in the distal direction, which, in particular when removing thrombi from blood vessels, can lead to further downstream occlusion of smaller blood vessels.

By the fluid-tight, flexible cover of the receiving area is further achieved that the receiving area in the expanded state with the concretion to be removed forms the substantially closed cavity in which the pressure with the aid of the pressure generating unit is adjustable. The fluid-tight cover ensures that the pressure generated in the cavity is locally limited. At the same time, the vessel wall in the pressurized area is stent-like supported by the catcher member, so that collapse of the blood vessel is prevented. The flexibility of the cover allows the catcher element to be converted from a compressed state to an expanded state. This compressibility or crimpability ensures that the catcher element can be guided through a catheter, in particular a microcatheter, to the treatment site. The catcher element is unfolded or expanded in the region of the treatment site and preferably assumes the cylindrical shape described in the context of this application. Furthermore, an interruption of the blood flow is achieved by the flexible cover in the expanded state, so that an uncontrolled detachment of concretion particles with the possible consequence of a distal vessel closure is avoided.

The catcher element may comprise a hose-like connection region with a fluid-tight cover, which is arranged proximal to the receiving region and fluidly connects the receiving region with the pressure-generating device.

The hose-like connection area allows the

Pressure generating device away from the catcher element, for example extracorporeal, can be arranged. The fluid connection thus creates a simple possibility for coupling the extracorporeally generated pressure into the capture element, in particular the receiving region. The fluid conducted into the receiving section through the hose-like connection region can be both a liquid and a gas include. This means that the pressure generation in the catcher element, in particular in the limited by the receiving portion and the calculus to be removed cavity is hydraulically or pneumatically. Hydraulic pressure generation is preferred, preferably biocompatible fluids being used as the hydraulic fluid. For example, the hydraulic fluid may include an isotonic saline or Ringer's lactate solution.

The receiving area may further comprise a substantially funnel-shaped transition section connected to the connection area. The funnel shape ensures that the cross-sectional diameter of the hose-like connection region or a pressure line which connects the catcher element to the pressure-generating unit is relatively small, so that the pressure line can be easily placed in the blood vessel, without the flow conditions in proximal, in particular branching, Affect blood vessels. The funnel-shaped transition section thus makes it possible to control or actuate the catcher element via a relatively small feed line, wherein the cross-sectional diameter of the catcher element during the treatment, however, is adapted to the cross-sectional diameter of the treatment location.

In a preferred embodiment, the filter region is substantially hollow cone-shaped or umbrella-like and forms a distal tip of the catcher element. In conjunction with the funnel-shaped transition section, the catcher element with the hollow cone-shaped or umbrella-like filter region essentially forms a cylindrical shape, each with tapered base surfaces. This shape increases the stability of the expanded catcher element. Further, the filter area formed as a tip enables an efficient filtering function, since the filter area, which is located distally of the concretion, forms a basket-like collecting element, in the cavity of which detachable concretion or thrombus particles can hold. Moreover, the umbrella-like shape of the filter region causes entrapped thrombus particles to be encapsulated and removed from the body vessel upon compression of the capture element in the umbrella-like filter region. If the catcher element is positioned such that the blood flow in the blood vessel extends from proximal to distal, ie from the receiving area to the filter area, it is further achieved with the umbrella-like filter area that the filter area completely fills the vessel cross section. Thus, it is prevented that particles are swept past the filter area in downstream vascular areas. Preferably, the filter area has a holding section which is adapted to receive a guide wire. The guide wire can be arranged in the tip of the filter region or catcher element or connected to the tip or connectable. With the guide wire, which is guided substantially in the axial direction by the catcher element, a simple and secure positioning of the catcher element is achieved in the treatment area. Further, the guidewire allows expansion of the capture member by pulling the guidewire in a proximal direction after positioning the capture member. In this case, the tube-like connection region is held stationary at the proximal end of the catcher element. In this way, the catcher element is shortened in length, so that the cross-sectional diameter widens, ie the catcher element expands.

The filter region may be at least partially fluid-tight or fluid-permeable. It is preferred that the filter area is made fluid-permeable, so that small blood components, such as platelets or erythrocytes, can pass through the filter area uninfluenced. The permeability of the filter area is limited to substantially fluid constituents of a body fluid, in particular blood. This means that foreign bodies that are larger than the usual cell size are retained by the filter area. This concerns in particular thrombi or thrombus components. The filter region is preferably adapted such that particles having a size of at most 1 mm, in particular at most 0.8 mm, in particular at most 0.6 mm, in particular at most 0.4 mm, in particular at most 0.2 mm, in particular at most 0.1 mm, are retained or are fϊlterbar.

Fluids in the context of the application are not limited to purely liquid components. Rather, in the context of the application, solid constituents are also attributed to a fluid if, overall, a substantially fluid-like character is present. In particular, this is true in the context of the fluid blood, which also contains solid cell components, such as platelets or erythrocytes, which are attributed to the fluid. Foreign bodies, which are substantially larger than individual cell bodies or foreign bodies, which are essentially formed from cell clusters, are not attributed to the fluid in the context of the application as a fluid constituent.

In a further preferred embodiment of the device according to the invention, the webs of the inlet region extend substantially rectilinearly or helically, in particular helically, in the axial direction. In this way, the cutting properties of the webs are promoted during rotation of the catcher element. Especially with a helical arrangement The webs are particularly advantageous as a cutting elements used to detach the concretion of the vessel wall.

The webs of the inlet region may comprise wire elements, tapes and / or threads. Preferably, the catcher element comprises a grid-shaped, which forms the connection area, the receiving area, the inlet area and / or the filter area. Thus, the production of a stable catcher element is accomplished by relatively simple means, with a simple and secure way is created by the grid mesh to assign the catcher element the necessary flexibility, so that a simple transfer of the catcher element is achieved by a compressed in an expanded state.

The catcher element thus receives an overall stent-like construction. The mesh may also be made of materials known in the art of making stents. For example, the mesh may include a shape memory material, in particular a shape memory metal such as a nickel-titanium alloy or stainless steel. Also possible are shape memory plastics.

Preferably, the wire elements at least partially form the grid mesh. The catcher element can therefore be constructed as a whole in one piece from wire elements, wherein the wire elements are preferably brought together in the inlet region in order to form the webs. Overall, the grid mesh preferably comprises 12, 16, 24, 32 or 48 wire elements.

In a particular embodiment, the mesh may comprise meshes which are larger in the inlet area than in the receiving area. In the case of a stent-like structure of the catcher element, therefore, the receiving area has a relatively small mesh size or pore size. The pores or meshes are preferably formed by wire-like extending wire elements. By combining a plurality of wire elements to a web larger meshes are provided in the inlet region, which form the inlet openings of the inlet area.

Preferably, the meshes are smaller in the filter area than in the inlet area, in particular at most as large as in the receiving area. In this way, it is ensured that detaching thrombus particles are efficiently retained by the filter area. At the same time a blood flow through the filter is made possible, so that the removal of the concretion of the physiological blood pressure from distally can act on the calculus. Of the Physiological pressure supports the detachment of the thrombus, so that the negative pressure generated proximal to the calculus can be kept relatively small.

The meshes in the receiving region, in the connection region and / or in the filter region can be at least partially covered or coated with the flexible cover. Preferably, the meshes in the receiving region and in the connecting region are completely covered with the cover, so that the closed cavity is formed in the receiving or connecting region in cooperation with the concrement or thrombus. The meshes of the filter area may be partially provided with a cover, so that pores are formed by the fluid-tight cover, which are permeable to fluids and impermeable to solid components. Overall, the mesh size in the filter area can be chosen to be relatively large in this way, whereby the number of wire elements of the mesh is minimized. The flexible cover nevertheless ensures that the filter function of the filter area is not impaired.

The invention further comprises a device for removing concrements from body vessels with a tubular catcher element, which can be converted under the influence of an external constraint from a state with a first cross-sectional diameter in a state with a second cross-sectional diameter which is smaller than the first cross-sectional diameter such that the catcher element in the state with the second cross-sectional diameter in a delivery system, in particular a catheter, is insertable. The catcher element has a proximal receiving area, an inlet area and a distal filter area. The inlet area extends longitudinally between the filter area and the receiving area and is connected to the filter area and the receiving area, respectively. The inlet region comprises webs which are arranged on a cylinder jacket surface in a circumferentially spaced manner and which delimit entry openings for the concrement.

The above-mentioned concretion-removing apparatus is not limited to the enclosure of the receiving portion with a fluid-tight cover. The device is thus disclosed and claimed even without flexible sealing. Alternatively, the device may also be combined with a flexible cover as disclosed above. In contrast to WO 2006/031410 A2, the device according to the invention for removing concrements is designed as an integrated catcher element which combines the receiving area, the inlet area and the filter area in a single coherent element. The device according to the invention has the advantage of a compact and simple construction which is safe to handle. All mentioned in the subclaims or in the above-mentioned imple mentation features and all the features mentioned in the following detailed description are also disclosed and claimed in the context of the above-mentioned device according to the invention without cover.

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

Fig. 1 is a side view of a catcher element of the device according to the invention according to a preferred embodiment;

FIG. 2 is a perspective view of the catcher element of FIG. 1; FIG.

Fig. 3 is a side view of a catcher element of the device according to the invention according to a further preferred embodiment;

4 shows a perspective view of the catcher element according to FIG. 3;

5 shows a side view of a catcher element of the device according to the invention according to a further preferred embodiment; and

6 is a perspective view of the catcher element according to FIG. 5.

Fig. 1 shows the catcher element 100 in the expanded state or in the idle state. This means that act in this state on the catcher element 100 no external constraints. The released state of the catcher element 100, i. when positioned in a body vessel, differs only slightly from the resting state by the cross-sectional diameter of the catcher element 100 in the released state is slightly reduced compared to the expanded state.

The catcher element according to FIG. 1 has an essentially cylindrical basic shape in the expanded or released state. The distal and the proximal end of the cylindrical shape are tapered. The catcher element 100 is divided into four different functional areas. In particular, the catcher element 100 comprises a connection region 160, a receiving region 110, an inlet region 130 and a Filter region 150. The connecting portion 160 forms a proximal portion of the catcher element 100 and is formed substantially tubular. The connection region 160 further comprises a cover 115, which covers the connection region 160 in a fluid-tight manner. The cover 115 is preferably flexible or foldable. In order to promote the detachment of a concretion or thrombus from the vessel wall and to protect the vessel wall, the receiving area 110 and / or the filter area 150 preferably have one

Cross-sectional diameter which is at least as large as the cross-sectional diameter of the inlet portion 130th

Distal to the connecting region 160, the receiving region 110 is arranged. The receiving region 110 comprises a proximally arranged transition section 113 and a cylindrical section 112, which is arranged distally of the transition section 113. The transition section 113 is funnel-shaped, wherein the larger funnel base surface faces the cylindrical section 112. The funnel tip of the transition section 113 merges into the connection region 160.

The larger part of the receiving area 110 is assigned to the cylindrical portion 112. This means that about two-thirds of the length of the receiving area 110 forms the cylindrical portion 112. Other conditions are possible. For example, the receiving region 110 may be designed so short that the transition section 113 provided with the cover 115 is connected substantially directly to the inlet region 130.

The cylindrical portion 112 tapers in the proximal direction and forms the transition portion 113, which couples the cylindrical portion 112 with the hose-like connection portion 160, wherein the tubular connection portion 160 has a substantially smaller cross-sectional diameter than the cylindrical portion 112. The difference in cross-sectional diameter between cylindrical Section 112 and connecting region 160 varies in the released state depending on the cross-sectional diameter of the vessel in which the catcher element 100 is inserted. In the compressed state, when the catcher element 100 is disposed within a catheter to supply it to the treatment site, the cylindrical portion 112 and the catcher element 100 have a substantially cross-sectional diameter corresponding to the cross-sectional diameter of the connection portion 160.

The receiving region 110 also has a flexible, fluid-tight cover 115. The flexible, fluid-tight cover 115 therefore extends beyond the connection region 160 the transition portion 113 to the cylindrical portion 112, so that both the connecting portion 160, and the receiving portion 110 is completely covered by the flexible cover 115.

The flexible cover 115 or coating may comprise a metal or plastic film. The cover 115 may be applied by spraying and / or dip coating, for example, to a grid structure which forms the connection region 160 and the receiving region 110. The flexible cover 115 may be applied both on an inner side, as well as on an outer side of the lattice structure or on both sides. It is also possible that meshes are formed by the grid mesh, which are filled centrally with the flexible cover 115.

The inlet region 130 adjoins the receiving region 110 in the distal direction. The inlet region 130 comprises webs 135 which define inlet openings 140. According to FIG. 1, the webs 135 extend parallel to the longitudinal axis of the catcher element 100. It is also possible for the webs 135 to extend across the inlet region 130 in crossing, wave-like or spiral-shaped or helical or helical fashion. A crossing arrangement is shown in FIGS. 3 and 4. Figures 4 and 5 show an embodiment of the catcher element 100 according to the invention, in which the webs wave-like manner over the Einlas sbereich 130 extend. The webs 135 are preferably formed of wire elements that emerge from the grid, which forms the connecting region 160 and the receiving region 110. In this case, the wire elements in the inlet region are combined in pairs or groups and preferably intertwined, so that the webs 135 have an increased stability. The wire elements may comprise flat bands. The inlet openings 140 have a size that is adapted to allow concretions to be removed, in particular thrombi, to penetrate into the inlet area 130. The length of the inlet region 130 is preferably adapted such that the inlet region 130 can be securely positioned in the region of a thrombus.

Distal to the inlet region 130, the filter region 150 is further arranged, which has a funnel shape substantially complementary to the transition section 113 of the receiving region 110. This means that the filter region 150 tapers in the distal direction and forms a tip 155 of the catcher element 100. In the region of the tip 155, the filter region 150 further forms a holding section 153. The holding section 153 is adapted such that a guide wire (not shown), which extends substantially centrally along the axis of rotation of the catcher element 100, with the filter region 150, in particular the holding portion 153, connectable or connected. The tip 155 may also have a passage through which the guide wire is guidable. By means of a suitable connecting device, the guide wire can be connectable to the tip 155 at least temporarily or temporarily.

In the perspective views according to FIGS. 2 and 4, it can be clearly seen that the catcher element 100 has a substantially rotationally symmetrical design and forms a cavity 120 in the region of the receiving region 110 in the expanded state. The cavity 120 is preferably designed free of installation and is open in the distal direction to the inlet region 130. When using the catcher element 100, the cavity 120 is closed by the calculus to be removed by placing the calculus in the inlet region 130. As a result, an active space for pressure generation is created in the receiving area HO, which is encapsulated by the surrounding vessels or body cavities.

The catcher element 100 can also have marking elements, which can be represented in particular under the influence of X-ray radiation. For example, at the top 155 and / or at the webs 135 marking elements may be arranged to allow secure positioning of the catcher element 100 under X-ray control. The marker dementer or X-ray markers may include radiopaque materials such as gold, platinum or tantalum.

The device according to the invention can also have the following features:

It can be clearly seen in FIGS. 3 and 4 that the catcher element 100 can be formed entirely from a wire mesh braid. In this case, the wire elements of the lattice mesh form meshes or pores, which may have different sizes in different areas of the catcher element 100. In a preferred embodiment, the inlet region 130 has larger pores than the distal filter region 150 and the proximal capture region 110. This facilitates the movement of thrombus or thrombus particles into the capture region 110. The wire elements forming the fine mesh in the receiving area 110 may converge in the inlet area 130. In this way, the pore size in the inlet region 130 is increased. Due to the coarse-meshed diamond shape of the mesh in the inlet region 130, a thrombus can be received in the catcher element 100.

It is also possible for the catcher element 100 to comprise, partially or in part, a laser-cut structure and / or a wire mesh or grid mesh and / or plastic elements. Combinations of such structures are possible. For example, the inlet region 130 may comprise a laser-cut structure and the filter region 150, in particular the cover 115, may comprise a plastic element. The structures can also vary within a functional area. In particular, the receiving region 110 may have a mesh in the transition section 113 and a laser-cut structure in the cylindrical section 112. Other combinations are also possible.

When using the catcher element 100 or during the removal of a concretion, the webs 135 or the wire groups forming the webs 135 can pass through the concretion or past the concretion. The function of the device according to the invention is ensured in both alternatives. If the wire members 135 extend centrally through the thrombus, there is a possibility that the ribs 135 will intersect radially through the thrombus upon expansion of the inlet region 130, so that the thrombus or concretion is divided into smaller segments. The removal of the calculus is favored in this way. If the webs 135 are arranged adjacent to the edge of the thrombus or against the vessel wall, a cutting effect can be achieved by rotation of the catcher element 100.

When placing the catcher element 100 in the treatment area, the webs 135, in particular the wire elements that form the webs 135, are pulled radially outwardly through the grid mesh in the filter area 150 and in the receiving area 110. This effect can be accelerated by a slight rotational movement of the catcher element 100 about the longitudinal axis.

The mesh in the filter area 150 is preferably formed fine mesh. It is also possible to provide the grid mesh in the filter area 150 at least partially or partially with the cover 115 or a coating. In this way, the danger that comes from detached Thrombuspartikeln reduced. It is possible for the filter region 150 to be partially fluid-permeable. In particular, smaller passages through the filter area 150 may be left open to ensure sufficient pressure gradient and blood flow through the filter area 150. Alternatively, the grid structure of the distal filter area can be completely coated or completely provided with the cover 115. In this way, the filter area 150 in combination with the funnel shape forms a kind of check valve. The filter area 150 may also include a diaphragm that acts as a check valve. When sucking the calculus by creating a negative pressure in the Receiving area 110 is achieved by the funnel shape of the fully coated filter area 150, a subsequent flow of blood. As soon as the negative pressure in the receiving region 110 subsides, the filter region 150 closes the blood vessel so that a blood flow is blocked in the distal direction.

It is also possible that the filter area 150 comprises at least one, in particular two or more, pressure compensation openings. The pressure compensation opening can be arranged, for example, centrally in the filter area 150, wherein the filter area 150 is completely provided with the fluid-tight cover 115. Another arrangement of pressure equalization holes is possible.

The mode of operation of the device according to the invention is explained in more detail below:

In a first step, a guidewire is inserted into the blood vessel to remove a thrombus or blood clot. The guidewire is passed by the thrombus to be removed until the tip of the guidewire is placed distal to the thrombus. In a second step, a microcatheter is guided over the guide wire to the treatment site. The microcatheter is positioned so that the tip of the microcatheter is placed distal to the thrombus. After removal of the guidewire, the capture element 100 is inserted into the microcatheter, with the capture element 100 in the compressed state in the microcatheter. The capture element 100 is released from the tip of the microcatheter with the tip of the microcatheter positioned to expand the filter region 150 distally of the concretion to be removed. Thus, first the filter function of the catcher element 100 is used, so that no particles of the thrombus can be removed from the treatment site on further use of the device according to the invention.

By means of a relative movement between the microcatheter and the capture element 100, the inlet region 130 is subsequently expanded, with the inlet region 130 being positioned such that the inlet region 130 is expanded in the region of the thrombus or thrombus. The catcher element 100 is further released from the microcatheter so that the receiving area 110 expands proximally of the thrombus. Preferably, the expansion process of the catcher element 100 is accomplished by a continuous retraction of the microcatheter. This procedure is known, for example, in the positioning of stents without a balloon catheter and therefore familiar to the physician. After positioning and expansion of the catcher element 100, aspiration or pressure generation in the cavity 120 is started. The receiving region provided with the flexible and fluid-tight cover 115 seals the vessel wall, so that during pressure generation, in particular during suction or aspiration, a pressure gradient arises between the proximal and distal sides of the thrombus. In this way, the thrombus is released and moved into the receiving area 110. The detachment of the thrombus can be assisted by the fact that the catcher element 100 is rotated about its own axis at least in segments. In this case, the rotation in both directions, preferably oscillating, take place. In this way, the webs 135 are used as cutting elements that separate the thrombus from the vessel wall. Thrombus particles in particular can be released when cutting off the thrombus. The distal filter region 150 ensures that the particles are not transported away into downstream blood vessels. Thus, the filter area 150 reduces the risk of distal emboli.

After the thrombus has been moved into the receiving area 110, it is possible to proceed with the generation of pressure, in particular a vacuum generation or aspiration, in order to also suck off particles that have been swept into the filter area 150.

The connection section 160 or the pressure line is adapted in such a way that a guide wire can be guided through the pressure line or the tube-like connection section 160, so that possible blockages which may arise during the aspiration of thrombus particles can be released. Instead of a guide wire, it is also possible to use a device which has been produced especially for the purpose of solving blockages in pressure lines and which, for example, has an enlarged diameter at least partially or partially in a distal region.

It is also possible to assist the aspiration of the thrombus by moving the catcher element 100 in the distal direction after positioning in the blood vessel during pressure generation by gently pushing it. This movement causes the receiving region 110 or the inlet region 130 to expand radially and slightly expand the vessel wall, so that the thrombus is more easily detached from the vessel wall. By slightly pushing the catcher element 100 in the distal direction, further improved sealing of the coated receiving area 110 against the vessel wall can be achieved, whereby a negative pressure generated in the cavity 120 can be increased. The device according to the above-described embodiments is further disclosed and claimed without the cover 115. Thus, all the supporting structures shown in FIGS. 1 to 6 are disclosed in the form of further embodiments, which differ from the embodiments disclosed above in that no fluid-tight cover and thus no vacuum function is provided. All other features of the embodiments according to FIGS. 1 to 6 are maintained.

Moreover, an arrangement is disclosed, which comprises a supply device, in particular a catheter, and a device according to the invention for removing concrements, in particular a device according to the exemplary embodiments described above. In this case, the catcher element is retractable into the feeder or the catcher element can be released from the feeder.

In connection with all exemplary embodiments or generally in connection with the invention, it is disclosed that the various regions, in particular the receiving region, the inlet region and the filter region, are connected to each other on the circumference. Concretely, the inlet region 130 is connected proximally to the receiving region 110 and distally to the filter region 150. The various areas of the catcher element 100 thus form a coherent, integral structure that is uniformly manageable, in particular uniformly displaceable relative to the feed device.

In the embodiments without a fluid-tight cover, the fixation of the thrombus or concretion for the purpose of removal takes place exclusively mechanically.

LIST OF REFERENCE NUMBERS

100 catcher element

110 recording area

112 cylindrical section

113 transition section

115 cover

120Hohlraum

130 inlet area

135 bridges

140 entrance openings

150 filter area 153 holding section

155 point

160 connection area

Claims

claims

A device for removing concrements from body vessels with a tubular, compressible catcher element (100), which can be converted under the influence of an external constraint of a state with a relatively larger cross-sectional diameter in a state with a relatively smaller cross-sectional diameter, as by geke nz eic hn et in that the capture element (100) has an inlet region (130) which extends in the longitudinal direction between a distal filter region (150) and a proximal receiving region (110) and comprises webs (135) arranged on a cylinder jacket surface in a circumferentially spaced manner, the inlet orifices ( 140), the receiving area (110) having a fluid-tight, flexible cover (115) which, in use within the receiving area (HO), forms a cavity (120) which can be closed by the calculus to be removed

Pressure generating device is operatively connected such that in the cavity (120) for moving, in particular for releasing the calculus to be removed, a different pressure is adjustable than outside the cavity (120).

2. Device according to claim 1, characterized in that the catcher element (100) comprises a hose-like connection region (160) with a fluid-tight cover (115), which is arranged proximally to the receiving region (110) and the receiving region (110 ) fluidly connected to the pressure generating device.

3. A device according to claim 2, characterized geke nnz eichn e t e, that the receiving area (110) comprises a substantially funnel-shaped transition portion (113) which is connected to the connecting portion (160).

4. The device according to at least one of claims 1 to 3, characterized ge n e ez eic hnet, that the filter region (150) is formed substantially in the form of a hollow cone or umbrella and a distal tip (155) of the catcher element (100).

5. Device according to claim 1, characterized in that the filter region (150) has a holding section (153) which is adapted to receive a guide wire.

6. Device according to claim 1, characterized in that the filter region (150) is designed to be at least partially fluid-tight or fluid-permeable.

7. The device according to at least one of claims 1 to 6, characterized Porsche Style in that the webs (135) extend substantially in a straight line or wave-like or helical, in particular helical, and / or crossing in the axial direction.

8. The device according to at least one of claims 1 to 7, characterized in that the webs (135) of the inlet region (130) comprise wire elements, tapes and / or threads.

9. Device according to claim 8, characterized in that the wire elements are braided or comprise laser-cut structural elements.

10. The device according to at least one of claims 1 to 9, characterized in that the catcher element (100) comprises a mesh which includes the connection region (160), the receiving region (HO), the inlet region (130) and / or forms the filter area (150).

11. The device according to claim 10, as characterized by gekenn z ei c h n e t that the wire elements at least partially form the grid mesh.

12. Device according to claim 11, characterized in that the grid mesh comprises meshes which are larger in the inlet area (130) than in FIG Recording area (110).

13. Device according to claim 12, characterized in that the meshes in the filter region (150) are smaller than in the inlet region (130).

14. Apparatus according to claim 12 or 13, characterized in that the stitches in the receiving region (110), in the connecting region (160) and / or in the filter region (150) are at least partially covered by the flexible cover (115) or are coated.

15. Apparatus for removing concrements from body vessels with a tubular catcher element (100), which can be converted under the influence of an external force from a state with a first cross-sectional diameter into a state with a second cross-sectional diameter which is smaller than the first cross-sectional diameter such that the catcher element (100) in the state with the second cross-sectional diameter can be introduced into a delivery system, in particular a catheter, characterized in that the capture element (100) has a proximal receiving area (110), an inlet area (130) and a distal area Filter region (150), wherein the inlet region (130) extends in the longitudinal direction between the filter region (150) and the receiving region (110), with the filter region (150) and the receiving region (110) is respectively connected and on a cylindrical surface in the circumferential direction spaced apart webs (135) comprises the entrance Limit openings (140) for the calculus.