WO2009077203A2

WO2009077203A2 - Device for endovascular treatment, particularly for removing concretions from body vessels

Info

Publication number: WO2009077203A2
Application number: PCT/EP2008/010906
Authority: WO
Inventors: Giorgio Cattaneo; Werner Mailänder
Original assignee: Acandis Gmbh & Co. Kg
Priority date: 2007-12-19
Filing date: 2008-12-19
Publication date: 2009-06-25
Also published as: WO2009077203A3; DE102007061238A1

Abstract

The invention relates to a device for endovascular treatment, particularly for removing concretions from body vessels, comprising a receiving element (1) and a distal element (2), which can be moved relative to each other from an open position into a closed position, wherein the receiving element (1) comprises a distal opening (14), which is arranged opposite the distal element (2) and in the open position is arranged at a distance from the distal element (2). It is characterized in that the distal opening (14) of the receiving element (1) can be closed by a proximal end (21a) of the distal element (2) such that both elements (1, 2) form a substantially closed hollow chamber in the closed position for receiving an object (42), particularly a concretion. The invention further relates to a device for endovascular treatment, which is characterized in that the distal element (2) is adjusted such that a radial diameter can be increased as a function of the axial force component acting on the object (42).

Description

Device for endovascular treatment, in particular for removing concrements from body vessels

description

The invention relates to a device for endovascular treatment, in particular for removing concrements from body vessels, according to the preamble of patent claim 1. Such a device is known from DE 10 2005 059 670 Al.

The formation of blood clots, especially thrombi in blood vessels, involves the risk of partial or complete occlusion of a blood vessel. In the occlusion of vessels carrying oxygen, downstream of the occlusion there is an undersupply of the tissue with oxygen and other nutrients. Currently, there are several approaches to therapy for such vascular occlusion that are essentially aimed at dissolving or removing the blood clot. An established method for the treatment of thrombi in human arteries is the drug thrombolysis, ie the dissolution of the blood clot with the help of drugs. However, an effective treatment is only possible if the treatment takes place at short notice, in particular no later than three hours after the onset of the symptoms. Furthermore, there is the danger of life-threatening side effects, such as a cerebral hemorrhage due to the strong blood-thinning drug.

As an alternative to drug treatment, it is known to mechanically remove blood clots from blood vessels. One known way to remove thrombi is to break up the blood clot in the bloodstream, releasing thrombus particles that can be removed from the vessel by means of an aspiration catheter. However, such devices have the disadvantage that particles passing through the Aspiration catheter can not be removed, can lead to closure of other, downstream vessels. Furthermore, in such devices a complete removal of the thrombus is not guaranteed. In particular, adhering to the vessel walls particles are often not eliminated.

It has been proposed to remove blood clots by corkscrew-shaped devices. WO 02/02162 A2 shows such a device with a catheter having a corkscrew tip, wherein the corkscrew tip is connected to the blood clot by helical motion. The blood clot is thus withdrawn from the blood vessel until it is removed in a larger blood vessel by an aspiration catheter. By transporting the blood clot over a relatively long distance there is a risk that particles of the thrombus detach and in turn lead to occlusions of smaller blood vessels. Furthermore, the material of the catheter tip is heavily stressed by the rotational movement, so that the catheter tip can break by over-torsion.

According to DE 10 2005 059 670 A1, therefore, a device for removing thrombi from blood vessels is proposed which comprises a cage structure and a distal element, which are arranged so as to be longitudinally displaceable relative to one another such that the distal element can be introduced into the cage structure. In this case, the distal element on radially outwardly projecting fibers, which engage in a blood clot and fix this and stabilize. To remove the blood clot, the distal element is pushed through the blood clot by means of a guidewire and then withdrawn with the radially outward fibers entangled in the thrombus so that the thrombus is fully connected to the distal element. The distal element is completely pulled into the basket structure with the thrombus and together with the basket structure removed from the blood vessel. The disadvantage of the brush-like structure of the distal element is that during the penetration or removal of the thrombus particles can be stripped off, which deposit in more distant, smaller blood vessels and serve there as germs for a new formation of a clot. Furthermore, there is a risk of damaging the vessel walls by contact with a plurality of fiber ends due to the movement of the brush-shaped distal element.

The invention is therefore based on the object to provide a device for endovascular treatment, which is a simple, safe and efficient removal of Kon- From body vessels, the risk of known side effects, such as particle detachment and vessel wall injuries is reduced.

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

The invention is therefore based on the idea to provide a device for endovascular treatment, in particular for removing concrements from body vessels, with a receiving element and a distal element, which are movable from an open position and a closed position relative to each other, wherein the receiving element a distal opening which is spaced from the distal element and spaced apart from the distal element in the open position. In this case, the distal opening of the receiving element is closable by a proximal end of the distal element such that the two elements in the closed position form a substantially closed cavity for receiving an object, in particular a concretion.

The invention is particularly suitable for the removal of blood clots from blood vessels. Although the invention will be described below using blood vessel clot removal as an example, other uses of the device involving removal of body cavity objects are also encompassed by the invention.

It should also be noted that the room designations and direction designations refer distally and proximally to the position of the user, in particular the physician, who uses the device. Accordingly, the distal element is further remote from the operator of the device with respect to a proximal element.

The device according to the invention enables an encapsulation of an object, in particular concrements, wherein the object is completely enclosed. In this case, the placement of the object in a substantially closed cavity, which is formed by the two elements, ensures that a separation of particles is avoided when the object is removed. For this purpose, the invention provides that the proximal end of the distal element in the closed position closes the distal opening of the proximal element. The object, for example a blood clot, can be transported with the device according to the invention, wherein the object during the Transportes completely encapsulated and thus a separation of particles is avoided. In this case, the device according to the invention ensures a stable transport of the object even over longer distances, so that there is no need to remove the object by an aspiration catheter when it has been transported through the device in a larger vessel. Rather, it is possible to remove the object completely by means of the device according to the invention completely from the body. In this way, a fast and safe removal of objects from body vessels is possible.

The distal element preferably has a stop at the proximal end. For encapsulating an object, the two elements are moved relative to one another, wherein the stop at the proximal end of the distal element has the advantage of contacting the object, so that the distal element, in particular the stop, fixes the object in the axial direction. In this way, the object can be pulled into the receiving element with the aid of the distal element or the receiving element can be slipped over the object. There are thus basically two possibilities for encapsulating an object with the aid of the device according to the invention. On the one hand, it is possible to hold the receiving element stationary and to move the distal element in the proximal direction against the receiving element, so that the object to be picked up is pulled into the receiving element by means of the stop at the proximal end of the distal element. On the other hand, it is possible to hold the distal element stationary and to push the receiving element distally over the object to be picked until the distal end of the receiving element forms a substantially closed cavity with the proximal end of the distal element. It is also generally conceivable that both movements, namely those of the distal element and the receiving element, are carried out simultaneously.

The stop at the proximal end of the distal element may be designed to close the distal openings of the receiving element. In this way, the distal opening of the receiving element is closed as soon as the object to be picked up is arranged in the receiving element or in the substantially closed cavity formed by the two elements.

In a preferred embodiment of the device according to the invention, the distal element, at least in the region of the proximal end, in particular in the region of the stop, has a rounded profile. The rounded profile makes it possible that the distal element for forming the substantially closed cavity can be pulled at least in sections into the receiving element, so that a Particularly secure closure of the distal opening of the receiving element is achieved by the distal element with the receiving element enters a plug or cork-like connection. Such a connection also ensures a secure closure of the distal opening of the receiving element when a change in the diameter of the receiving element takes place. The rounded profile of the distal element also has the advantage that upon contact of the distal element with a vessel wall, damage or injury to the vessel wall is avoided.

Preferably, the receiving element has a substantially funnel-shaped portion. When receiving an object, the funnel-shaped portion can serve to clamp the object, which is preferably transported by the relative movement of the two elements in the receiving element, so that a substantially non-positive connection between the funnel-shaped portion and the male object takes place to a Fixation and stabilization of the object to be recorded in the receiving element leads. Furthermore, the funnel-shaped portion of the receiving element has the advantage that the device when removing it from the vessel can be easily inserted into a delivery system, in particular a catheter, wherein the tip of the funnel-shaped section is preferably inserted into the catheter in the proximal direction. Through the funnel-shaped portion is achieved in the introduction of the device into the catheter, that the receiving element is folded and can be completely withdrawn into the catheter.

In a preferred embodiment, the receiving element has a cylindrical stent structure in the region of the distal opening. The cylindrical stent structure provides sufficient space and stability for receiving an object. In particular, the stent structure improves the dimensional stability of the receiving element during the relative movement between the distal element and the receiving element. The cylindrical stent structure is preferably connected to the funnel-shaped section on a proximal side, so that the object received by the stent structure is pushed into the funnel-shaped section by a further relative movement between the two elements and is fixed there in a substantially non-positive manner.

The funnel-shaped portion may further include spokes connected at their proximal ends to a proximal ring and at their distal ends to the cylindrical stent structure. In this case, the proximal ring has a smaller diameter than the cylindrical stent structure. The proximal ring can be used as a guide Serve or bearing for an actuating element, so that, for example, an actuating element designed as a guide wire is arranged coaxially to the axis of the receiving element and is axially movable relative to the receiving element.

In a further preferred embodiment of the device according to the invention, the receiving element has in a middle region a radially outwardly curved shape, in particular with a diameter that is greater than the diameter of the distal opening. Such an embodiment is particularly advantageous when the device according to the invention is used to remove blood clots in blood vessels. Preferably, the diameter of the radially outwardly curved shape is greater than the diameter of the blood vessel, so that the blood clot, as soon as it is received by the distal opening, achieved by the radially outwardly curved shape of the receiving element radial expansion of the blood vessel the vessel walls is released.

It is particularly advantageous if the receiving element has a cutting region acting in the axial direction in the region of the distal opening. As a result, a blood clot or, in general, an object can be separated from vessel walls by the receiving element being slipped over the object. It is possible that the cutting region acts by an axial movement of the receiving element in the distal direction, wherein it is not ruled out that the cutting action is achieved or improved by a rotational movement. Preferably, the cutting area has a slightly smaller diameter than the cylindrical stent structure, so that as the receiving element is moved to separate the clot from the vessel wall, the risk of damage to the vessel wall is minimized.

In a further preferred embodiment, the distal element can be widened in the radial direction. The widening of the distal element has the advantage on the one hand that the diameter of the distal element can be adapted to the diameter of the receiving element, so that a secure closure of the receiving element is possible. On the other hand, can be achieved by the expansion of the distal element that, for example, in blood vessels, the vessel walls are pressed radially outward, whereby the diameter of the blood vessel is increased, resulting in a separation of a voltage applied to the vessel walls blood clot or object.

The distal element may be connected to a guide wire, which is substantially axially displaceable relative to the receiving element. The guide wire allows in a secure and accurate placement of the distal element, preferably distal of the object to be recorded, and further constitutes an actuating element, with which the relative movement between the distal element and the receiving element is effected.

Preferably, in the compressed state, the distal element forms a distal-pointing tip. In particular, in the case of objects resting against the vessel walls, the tip pointing in the distal direction offers the possibility of penetrating the object, for example a blood clot, with the distal element, without causing significant detachment of particles of the object to be photographed. Furthermore, the tip, which is distinguished by the fact that the diameter of the distal element is smaller at its distal end than at its proximal end, also makes it possible to bypass an object through relatively small passages, for example along a vessel wall past a blood clot slide.

In a further preferred embodiment of the device according to the invention, the receiving element and / or the distal element each have a filter which is adapted such that in use at least parts of the object to be picked up are retained. In this case, the two elements take on an additional filter function, which ensures that, for example, detaching particles of the male object can not penetrate into smaller vessel segments and close them during the recording process. Rather, such particles are retained and encapsulated with the object to be picked and removed from the vessel.

Preferably, the distal element has a contact surface for engagement with a vessel wall. As a result, a gentle force transmission from the distal element is achieved on the vessel wall. The contact surface may extend in the axial direction of the distal element. This makes it clear that this is not a punctual, but a two-dimensional force transmission. The distal element may have a cylindrical stent structure in the area of the stop. The cylindrical stent structure can be open or provided with a cover and offers a further possibility to transmit the radial force over a flat area on the vessel wall. In a further preferred embodiment, the actuating element is detachably connected to a distal end of the distal element in such a way that the connection is released when a limit force applied by the actuating element to the distal end is exceeded. This avoids excessive distention of the distal element on stuck thrombi. In addition, the actuating element in the len loosened end position with a proximal end of the distal element cooperate such that a force acting in the proximal direction tensile force from the actuating element to the distal element is transferable. In this way, the distal element can be removed from the blood vessel when the thrombus is not mechanically detachable.

The invention further relates to a device for endovascular treatment, in particular for removing concrements from body vessels, according to the preamble of claim 20. Such a device is known from DE 698 31 968 T2.

DE 698 31 968 T2 discloses a mechanical device for removing clots with a distal filter. In this case, the distal filter on a proximal and a distal element, which are braided in each case of wires and are formed in the expanded state as balls. The two elements can basically assume two states, a compressed and an expanded state, the change between the two states being effected by an actuating element. The actuator consists of a sleeve over a guide wire, wherein the sleeve is connected to the proximal element and the guide wire is coupled to the distal end of the device. By a relative movement between the actuating element and the guide wire is a radial expansion or reduction of the diameter of the spherical filter. The device has the disadvantage that the force acting on the vessel wall radial force, which is caused by the expansion of the balls, is not or only poorly controllable.

The invention is therefore based on the object of specifying a device for endovascular treatment, in particular for removing concrements from body vessels, which allows an effective widening of a body vessel in order to release a concretion adhering to the vessel wall.

According to the invention, this object is achieved by the subject-matter of claim 20.

The invention is based on the idea of specifying a device for endovascular treatment, in particular for removing concrements from body vessels, with a distal element and an actuating element for an axial movement of the distal element, wherein the distal element has a stop which is adapted , by the axial movement of the distal member an axial force component to apply to an object arranged on the stop in use. In this case, the distal element is adapted such that a radial diameter of the distal element can be increased in dependence on the axial force component acting on the object.

The device according to the invention thus concretely enables a rapid and gentle removal of blood clots from blood vessels, since the distal element, after which it has been placed distally of a clot in the vessel, comes into contact with the clot to be removed when retracted with the stop. In order to remove the clot, which rests mostly on the vessel wall, it is necessary to exert a force, in particular tensile force on the distal element or on the stop on the object. The force needed to release the clot depends on the strength of the connection of the clot with the vessel wall. In the device according to the invention, this force component causes an increase in the radial diameter of the distal element, which results in that the vessel wall is moved radially outward, whereby the blood clot can detach from the walls. Due to the dependence of the axial force component of the radial expansion of the distal element, the expansion of the vessel diameter takes place only in the absolutely necessary degree to solve the clot. The removal of the object is thus particularly gentle.

In a preferred embodiment of the device according to the invention, the distal element has a spacing between a proximal end and a distal end which is variable as a function of the axial force component acting on the object. As a result, it is achieved in a particularly simple manner that there is a change in the radial diameter of the distal element as a function of the axial force component. Further, the change in the distance between the proximal and distal ends of the distal member provides a resilient function such that upon reduction of the axial force component, such as disengagement of the clot, a recovery occurs, the distance between the proximal and distal ends of the clot distal element and also the radial diameter of the distal element assumes its original value.

Preferably, the distal element has a substantially funnel-shaped section. Through the funnel-shaped portion of parts of the clot, when they detach when loosening the clot, be accommodated in a particularly simple manner, so that these fragments of the clot can be removed from the vessel. Furthermore, the distal element in the region of the stop can have a cylindrical stent structure, which is preferably connected to the funnel-shaped section on a distal side. The cylindrical stent structure allows for an improved adaptation of the distal element to the vessel walls, so that the distal element can completely fill the cross-section of the blood vessel.

Preferably, the funnel-shaped portion has spokes which are connected at their distal ends to a distal ring and at their proximal ends to the cylindrical stent structure. In this case, the distal ring has a smaller diameter than the cylindrical stent structure. The spokes largely prevent torsion of the distal element, so that the distal element as a whole is stabilized. In order to place the device according to the invention in a vessel, it is advantageous to introduce the device by means of a guide wire. Preferably, the guide wire is arranged coaxially with the axis of the distal element. Such an arrangement is particularly advantageously made possible by the distal ring, through which a guide wire can be guided.

Furthermore, the stop may comprise spokes which are connected at their proximal ends to a proximal ring and at their distal ends to the cylindrical stent structure. In this case, the proximal ring has a smaller diameter than the cylindrical stent structure. Preferably, the spokes are formed substantially S-shaped. The spokes on the stop of the distal element form a stop for the object to be removed from the vessel and also offer the possibility that the distal element can be flowed through by liquid, so that in particular when used in blood vessels blood flow to the subsequent tissue is not interrupted. The S-shaped structure of the spokes provides a uniform connection between the proximal ring and the cylindrical stent structure, so that the risk of injury, for example from vessel walls, is reduced by movement of the distal element.

In a preferred embodiment of the device according to the invention, the distal element comprises rings arranged at a proximal and a distal end, the diameter of which is essentially the same. The rings may be connected to form the distal member by longitudinally extending spokes which are radially outwardly arched in a central region of the distal member. The two rings offer the possibility of receiving a guide wire, while the outwardly curved spokes, the distal element substantially spherical form, which leads to a further reduction of the risk of injury, in particular the vessel walls.

In a further preferred embodiment, the stop comprises a curvature which extends substantially in the proximal direction. Due to the curvature of the stop, the radial expansion of the distal element in dependence on the axial force component can be achieved particularly easily.

Preferably, the distal element is at least partially substantially teardrop-shaped.

The stop may have an opening coaxial with the axis of the distal element. In this way, larger or larger changes in the radial diameter of the distal element are possible.

Furthermore, the actuating element can be coupled to the distal element at an axial end arranged opposite the stop. It is thereby achieved that the distance between the proximal and distal ends of the distal element is changed by movement of the actuating element in the direction of the object to be removed or removed when the object to be removed bears against the stop. By changing the axial distance, a radial widening of the distal element and thus also of the body vessel is effected, so that the object or clot is released from the vessel walls.

Advantageously, the actuating element comprises a guide wire, so that the device can be easily and safely placed in the vessel at the site to be treated.

In a further preferred embodiment of the device according to the invention, the distal element has a filter which is adapted such that in use at least parts of the object are retained. This ensures that, for example, by the active force component detached particles of the male object can not penetrate into smaller vessel segments and close them.

The invention is explained in more detail below on the basis of embodiments with reference to the accompanying schematic drawings. Show in it Figure 1 shows a longitudinal section of a device for endovascular treatment according to an embodiment of the invention in the compressed state;

FIG. 2 shows a longitudinal section of a device for endovascular treatment according to another exemplary embodiment in use;

FIG. 3 shows a longitudinal section of a device for endovascular treatment according to a further exemplary embodiment in use;

FIG. 4 shows a longitudinal section of a device for endovascular treatment according to a further exemplary embodiment in use;

FIG. 5 shows a longitudinal section of a device for endovascular treatment according to another exemplary embodiment in use;

FIG. 6 is a perspective view of the receiving element of an endovascular treatment device according to a preferred embodiment;

FIG. 7 shows a longitudinal section of a device for endovascular treatment according to a further exemplary embodiment in use;

FIG. 8 is a perspective view of the distal element of an endovascular treatment device according to a preferred embodiment; and

FIG. 9 shows a perspective view of the distal element of a device for endovascular treatment according to a further preferred exemplary embodiment.

FIG. 1 shows a device according to the invention in the compressed state within a microcatheter 33 with which the device according to the invention is introduced into a blood vessel. The device comprises a receiving element 1 with a proximal ring 11, which is arranged displaceably on an actuating element 3, in particular a guide wire 31. Distal of the receiving element 1, a distal element 2 is arranged on the actuating element 3. The distal element 2 is with its distal end 21d is connected to the actuating element 3 or guide wire 31. At the distal end of the receiving element 1 and at the proximal end 21a of the distal element 2, sliding elements 32 are respectively arranged, which glide along the vessel wall 41 during introduction of the device into a blood vessel 4, so that damage to the vessel walls 41 is avoided. For this purpose, the sliding elements 33 essentially have a rounded shape. During penetration of the device into the blood vessel 4, the device is completely disposed within the microcatheter 33.

FIG. 2 shows the device according to the invention in use, ie when removing a blood clot 42 from a blood vessel 4. The receiving element 1 and the distal element 2 are arranged inside a blood vessel 4, the distal element 2 distal to a blood clot 42 and the receiving element 1 an opposite side of the blood clot 42 is arranged. The two elements 1, 2 have taken the expanded state. The receiving element 1 has at the proximal end a proximal ring 11, which is arranged within the microcatheter 33. The proximal ring 11 is connected to a funnel-shaped portion 12, which generally defines the central area of the receiving element 1. The receiving element 1 further has a distal opening 14, which is arranged together with a cutting region 15 in the region of the distal end of the receiving element 1. Coaxially with the proximal ring 11, the actuating element 3 or the guide wire 31 extends through the receiving element 1. The guide wire 31 penetrates the blood clot 42 and is connected distally to the blood clot 42 to the distal element 2, in particular to the distal ring 22b. The distal ring 22b is located at the distal end 21b of the distal member 22, with the distal end 21b forming a point 28 substantially extending from the funnel-shaped portion 24. In use, the largest radial diameter of the distal element 2 corresponds to the diameter of the blood vessel 4, so that the distal element 2 rests at least in sections on the vessel walls 41 of the blood vessel 4. Between the contact surface of the distal element 2 with the vessel wall 41 and the blood clot 42, a proximal end 21 a of the distal element 2 is defined, which has a stop 23. The stop 23 in use at least in sections, in particular completely, abuts the blood clot 42 and serves to transmit a force from the distal element 2 to the blood clot 42. In this case, the area between the stop 23 and the distal opening 14 of the receiving element 1, apart from the actuating element 3, designed free of incorporation, so that the blood clot 42 can be freely received. Furthermore, in this way the largest possible contact surface between the stopper 23 and the blood clot 42 is provided. This is preferably achieved in that the stop 23 comprises spokes 26, 26a, which have a relative have a large cross-section, or at least partially covered by a film such that the largest possible contact surface and at the same time a sufficient blood flow is ensured by the distal element 2.

The abovementioned contact surface of the distal element 2 with the vessel wall 41 has a sealing function in order to avoid that parts of the concretion to be dissolved pass the distal element 2 into the bloodstream. The contact surface 25a extends in the axial direction of the distal element and thus forms a planar contact surface for the vessel wall. As a result, injuries to the vessel wall are avoided when the distal element 2 is expanded radially outwardly by the force acting on the calculus Axialkraftkomponente. In this case, the contact surface 25a may comprise individual grid elements, which are arranged at least in sections in the axial direction of the distal element 2 and, in the clamped state of the distal element 2, lie flat against the vessel wall 41. The contact surface 25a may also be arranged in the circumferential direction of the distal element 2 and extend in the axial direction such that the contact surface 25a forms a substantially closed wall of the distal element 2. An example of such a closed wall of the distal element 2 in the region of the contact surface 25a is shown in FIG. In the basket according to FIG. 8 or the distal element 2 according to FIG. 8, the cylindrical section 25 or the cylindrical stent structure 25 forms the contact surface 25a.

In this case, the contact surface 25a is arranged in the proximal region of the distal element 2 such that, when a concretion with an axial force component is acted upon by the distal element 2, the radial expansion of the distal element 2 occurs predominantly in the region of the contact surface 25a. This ensures that the vessel widening or the transmission of the radial force on the vessel wall in the region of the contact surface 25a and thus takes place in the area which allows a particularly gentle force on the vessel wall.

FIG. 3 shows a device according to the invention in use, wherein the device corresponds in its construction to the exemplary embodiment according to FIG. In contrast to the exemplary embodiment according to FIG. 2, however, the distal element 2 is arranged partially within the receiving element 1, wherein the distal element 2 completely closes the distal opening 14 of the receiving element 1, so that the blood clot 42 is held within the now formed cavity. In order to release the blood clot 42 by widening the vessel diameter of the blood vessel 4, the receiving element 1 can have a radially outwardly curved shape in a middle region (FIG. 4). Likewise, a radial expansion of the distal element 2 is possible, the distal element 2 according to FIG. 4 having a coaxial opening 29 which is arranged in the region of the stop 23. The opening is defined by sliding members 32 which slide along the blood clot 42 when the stopper 23 applies an axial force component to the blood clot 42. As a result of the sliding movement of the sliding elements 32, a radial widening of the distal element 2 is achieved, so that the vessel walls 41 are lifted off the blood clot.

FIG. 5 shows a device according to the invention with an encapsulated blood clot 42, wherein the two elements, the receiving element 1 and the distal element 2, enclose the blood clot 42 in a cavity and are withdrawn in a compressed state into a receiving catheter 34, so that the blood clot 42 moves with it the device is removed from the blood vessel 4.

Figure 6 shows an embodiment of the receiving element 1 with a proximal ring 11 which is arranged at a narrow end of a funnel-shaped portion 12. The funnel-shaped section 12 is connected to an end of a cylindrical stent structure 16 opposite the proximal ring 11. The funnel-shaped section 12 comprises spokes 13, which preferably have a rectangular cross-section. The spokes 13 may also have other cross-sections, such as round or oval cross-sections. The cylindrical stent structure 16 forms the distal opening 14 and comprises a cutting region 15 which makes it possible to detach a blood clot 42 from vessel walls 41 by sliding the receiving element 1 along the blood vessel 42 along the vessel wall 41. According to FIG. 6, the cylindrical stent structure 16 has a plurality of angularly arranged and interconnected struts. In general, other constructions of the cylindrical stent structure 16 are possible, in particular all known types of cylindrical wire structures or laser-cut structures. Furthermore, it is possible that the proximal ring 11 also has a stent structure. The spokes 13 preferably emerge from such a proximally arranged stent structure and form the distally arranged cylindrical stent structure 16, so that the receiving element 1 is made essentially in one piece.

FIG. 7 shows a further variant of the device according to the invention in use, wherein the guide wire 31 is inserted between the blood clot 42 and the vessel wall 41. is orders. In contrast to the above-mentioned embodiments, the guide wire 31 or the actuating element 3 does not extend through the clot 42, but past the clot 42. FIG. 7 clearly shows that the use of the device according to the invention is also possible in such cases when the guide wire 31 is deflected by the blood clot 42 when moving in the blood vessel 4 from its original path.

FIG. 8 shows an exemplary embodiment of a distal element 2 of a device for endovascular treatment. The distal element 2 comprises a proximal end 21a, a middle region with a cylindrical stent structure 25, a funnel-shaped section 24 and a distal end 21b. At the proximal end 21a, a proximal ring 22a is arranged, which is connected to S-shaped spokes 26a. The S-shaped spokes 26a are coupled to a cylindrical stent structure 25 at their ends opposite the proximal ring 22a. In this case, the cylindrical stent structure 25 has a larger diameter than the proximal ring 22a. The cylindrical stent structure 25 is further connected to a funnel-shaped section 24, wherein the largest diameter of the funnel-shaped section 24 corresponds to the diameter of the cylindrical stent structure 25. The funnel-shaped portion 24 has at the distal end 21b of the distal member 2 a minimum diameter corresponding to the diameter of the distal ring 22b which is connected to the funnel-shaped portion 24. Preferably, the funnel-shaped portion 24 is formed by spokes 26b which couple the distal ring 22b to the cylindrical stent structure 25. The cylindrical stent structure 25 can comprise any known structure, in particular a wire mesh. Furthermore, the distal element 2 has a filter 50, which spans the funnel-shaped section 24 and the cylindrical stent structure 25. In this case, the filter 50 may be arranged on an inner circumference, an outer circumference or between the spokes 26b or the structural elements of the stent structure 25. The filter 50 prevents parts of the clot 42, which dissolve during the treatment, from being able to lead downstream to further vascular occlusions. Rather, such particles are collected by the filter 50 and removed from the vessel 4 together with the device. In order to still allow blood flow and thus sufficient nutrient supply to the subsequent tissue, the filter 50 is preferably not completely closed, but has openings or pores of sufficient size to allow blood and blood components to pass therethrough Clots 42 are retained. FIG. 9 shows a further exemplary embodiment of the distal element 2 of the device according to the invention for endovascular treatment. The distal element 2 accordingly has a proximal ring 22a which is arranged at a proximal end 21a and a distal ring 22b which is located at a distal end 21b of FIG distal element 2 is arranged. The two rings are connected by spokes 26, which extend substantially in the longitudinal direction between the two rings 22a, 22b and are curved radially outwards in a central region of the distal element 2. The curved spokes 26 at the proximal end 21a form a stop 23, which comes into contact with the clot 42 in use. Once the clot 42 is placed within the receiving element 1 by movement of the distal element 2 or the receiving element 1, the stop 23 serves to close the distal opening 14 of the receiving segment 1.

In principle, the two elements 1, 2 may have structures other than those mentioned. For example, the receiving element 1 or the distal element 2 may be formed from a wire mesh or comprise the shape of a tapered coil spring.

The wire mesh has the advantage of high fine mesh, which improves both the filtration of particles and a possible coating with plastic. In addition, despite the closed cell structure, the wire mesh has a high degree of flexibility, so that both the distal element 2 and the receiving element 1 can be well positioned in the radius. In the braid, the wires can be connected together at the ends, whereby the stability is increased. For the connection are non-positive, positive or cohesive connections such as gluing, welding, soldering or other mechanical interlocks in question.

The connection between the distal element 2 and the actuating element 3, in particular the guide wire 31, is releasable, in particular detachable by a presettable axial force exerted by the guide wire 31 on the distal element 2 when the distal element 2 is pulled against a calculus to be detached becomes. The detachable connection can be achieved for example by a frictional or positive connection between the distal ring 22b or generally a holding element and the distal end 21b of the distal element 2, wherein the frictional or positive connection is adapted such that it dissolves when a limit force is exceeded , For this purpose, the distal ring 22b is fixedly connected to the guide wire 31 and detachably connected to the distal end 21b of the distal element 2. For example, you can the distal ring 22b and the distal end 21b of the distal element 2 have elastic components that deform radially with increased axial force. In this case, the distal end 21b can widen and / or the distal ring 22b taper. Another possibility is to set a predetermined frictional resistance between the distal ring 22b and the distal end 21b of the distal element 2, which is overcome when a certain axial force is applied by the guide wire 31, so that the two components move relative to each other and the lock to solve.

For example, it is possible to form the releasable connection by two coaxially arranged rings, in particular an outer ring and an inner ring, which are pressed together. The outer ring is fixedly connected to the distal end 21b and the inner ring to the guide wire 31 respectively. By pulling the guide wire 31 with a force exceeding the limiting force, the adhesive force between the two rings is overcome or a positive connection is released and the connection is released.

Instead of or in addition to the principle of detachable by exceeding an axial limit force connection, the distal ring 22b or generally a retaining element adapted to be locked to the distal end 21b, wherein the lock by unlocking movement of the guide wire 31, for example by rotation of the Guidewire 31 is released.

The releasable connection between the distal basket 2 and the guidewire 31 provides a safeguard to prevent the distal element 2 from being subjected to an excessively large axial force when the thrombus is too firmly anchored in the vessel. The releasable locking of the guide wire 31 thus prevents excessive radial expansion of the distal element 2 and protects the vessel wall.

In addition to the safety function of the distal member 2, the distal member 2 may be adapted to be removed from the vessel when the thrombus is so firmly seated in the vessel that mechanical disengagement by dilating the vessel and thrombus with an axial force is insufficient. In this case, the distal element 2 is compressible or collapsible such that the distal element 2 can be retracted by the thrombus in the proximal direction. For this purpose, provision may be made for the guide wire 31 or the distal ring 22b firmly connected to the guide wire 31 to cooperate with the proximal ring 22a of the distal element 2 such that the distal element 2 can be moved in the proximal direction without radial expansion. For this purpose, the distal ring 22b has an outer diameter which is equal to or is larger than the inner diameter of the proximal ring 22a, so that the distal ring 22b detached from the distal end 21b cooperates with the proximal ring 22a in the form of a stopper. Other ways of locking or anchoring the distal ring 22b with the proximal ring 22a are conceivable. In this case, the proximal ring 22a, which is firmly integrated in the structure of the distal element 2, has such a stability or strength that the tensile force transmitted to the proximal ring 22a by the guide wire 31 via the distal ring 22b detached from the distal end 21b extends the entire distal element 2 in the longitudinal direction and retracts through the thrombus. In doing so, the distal element 2 folds radially inwards as it passes through the thrombus.

It is also possible to first distally displace the catheter 33 through the thrombus and then actuate the safety mechanism so that the distal element 2 is pulled proximally through the abutment of the two rings 22a, 22b into the thrombus.

The combined safety mechanism of the distal element 2 generally comprises an actuating element 3, in particular a guide wire 31, which is detachably connected to the distal end 21b of the distal element 2. The releasable connection may comprise a positive, non-positive or material connection or other mechanical locking possibilities, which are solvable by exceeding a limit force which is transmitted from the guide wire 31 to the distal end 21b. This avoids excessive widening of the distal element 2 in a stuck thrombus.

In addition, the distal member 2 may be adapted such that the guide wire 31 (release position) disengaged from the distal end 21b cooperates with a proximal end 21a of the distal member 2 such that an axial force from the guide wire 31 is transferable to the proximal end 21a of the distal member 2 is (stop position). As a result, the distal element 2 can be stretched such that it folds radially inward. In addition, the distal element 21 can now be moved in the proximal direction without radial expansion, in particular through the thrombus, in order to remove the distal element 2 from the blood vessel. For the power transmission in the locking position different types of connections are possible. These include, for example, the abutment for the guide wire 31 formed at the proximal end 21a. It is also possible to provide other locking means in which, for example, the guide wire 31 is latched to the proximal end 21a, so that an axial force in both the proximal and distal directions is transferable. Finally, with the aid of the combined safety mechanism, the guide wire 31 can be transferred from a first locking position, in which the guide wire 31 is releasably connected to the distal end 21b, into a release position and a second locking position, in which the guide wire 31 engages with the proximal end 21a of the distal element 2 is connected.

The combined safety mechanism allows the distal element 2 to be removed from the vessel in the event that the thrombus is not mechanically detachable from the vessel wall without undue stress on the vessel wall.

Preferably, the elements 1, 2 made of plastics or metals, which have elastic properties. In particular, the elements 1, 2 may be made of nitinol.

Furthermore, the filter 50 can be formed, for example, from plastic, in particular polyurethane, Teflon or silicone. Alternatively, it is possible that the filter 50 comprises a plastic or metal foil. It is not necessary to apply the filter 50 or the film on the entire surface of the receiving element 1 or the distal element 2. As shown in Figure 8, the filter 50 may be applied only to the region between the tip 28 of the distal member 2 and the central region. The manufacture of the filter 50 preferably takes place by means of a coating, for example magnetron sputtering, of the underlying lattice or spoke structure.

The invention therefore offers several functions. Thus, a distal protection is ensured by the distal element 2, ie a complete interception of detaching clot parts is achieved by the distal element 2. Preferably, an at least impermeable for such particles filter structure serves. The filter structure can be formed both by a suitable arrangement and / or configuration of the spokes 13, 26, 26 a, 26 b or the cylindrical stent structure 16, 25 and by a cover, for example a film. Both the receiving element 1 and the distal element 2 may comprise such a filter structure. Furthermore, by the combination of the two elements, namely the distal element 2 and the receiving element 1, an encapsulation of the clot 42 can be achieved, so that the clot 42 can not be transported freely but enclosed in a dense structure up to larger vessel sections. The risk of detachment of clot parts during transport is thereby reduced. This also has the consequence that a suction of the Clot 42 can either be completely omitted by an aspiration catheter or the aspiration catheter can be positioned at least in wider vessel sections, to which the clot 42 can be transported by means of the device according to the invention.

The process of clot removal takes place in several steps. First, the device according to the invention, which is arranged in a microcatheter 33, is pushed together with the catheter 33 through the blood vessel 4 into the region of the clot 42. Preferably, the microcatheter 33 is pushed through the clot 42 or past the clot 42. In the case of pushing through, for example, an inflatable balloon or a deployable tip with a suitable profile can be used to center the microcatheter 33 in the blood vessel 4. In a further step, the microcatheter 33 is withdrawn so that the distal element 2 unfolds in the blood vessel 4. In this case, the distal element 2 covers substantially the entire cross section of the blood vessel 4 and thus acts as a filter for clot fragments. The unfolding or spreading of the distal element 2 can be effected by a restoring force, which is brought about by the elastic properties of the material used for the distal element 2. As a result of further retraction of the microcatheter 33, the receiving element 1 likewise extends up to the vessel wall 41, proximally of the clot 42. Preferably, the receiving element 1 is made of elastic materials, so that the propagation takes place automatically by the restoring force of the elastic material. It is possible that the receiving element 1 also performs a filter function for clot fragments.

The separation or separation of the clot 42 from the vessel wall 41 can be achieved in different ways. In a first variant, the distal element 2 is pulled in the proximal direction, so that the stopper 23 comes into contact with the clot 42. By further pulling the actuating element 3 proximally, the tip 28 of the distal element 2 is further moved in the proximal direction, while the stopper 23 on the clot 42 applies a force acting in the proximal direction. Due to the elastic properties of the distal element 2, the proximal movement of the tip 28 leads to a compression of the distal element 2 in the longitudinal direction and thus to a radial expansion, so that the vessel wall 41 lifted off the clot 42 and the clot 42 thus released from the vessel 4 becomes. If necessary, this process can be repeated several times, even in the form of a vibratory movement, until the clot 42 has completely detached from the blood vessel 4. By a further pulling movement on the actuating element 3, the distal element 2 is moved further in the direction of the receiving element 1, so that the clot 42 is placed in the receiving element 1.

In a further variant, the receiving element 1 can be pushed over the clot 42 in the distal direction. In this case, the cutting region 15 arranged in the region of the distal opening can be used to cut the clot 42 free of the vessel walls 41. It is also possible that the receiving element 1 in the expanded state in a central region has a radially outwardly curved shape, so that analogously to the radial expansion of the distal element 2, the vessel walls 41 are expanded radially outward and thus the clot 42 of the vessel walls 41 is solved. In general, all of the abovementioned detachment techniques can be used individually, in combination, simultaneously or alternately by the receiving element 1 and by the distal element 2.

After detachment of the clot 42 takes place by the relative movement of the receiving element 1 to the distal element 2, the encapsulation of the clot in the cavity, which is formed by the receiving element 1 and the distal element 2. Due to the rounded profile of the distal element 2 in the region of the stop 23, the distal element 2 slides into the receiving element 1, so that the receiving element 1 is closed by the distal element 2 in the region of the distal opening 14 of the receiving element 1. The clot 42 encapsulated in this way is then transported through the blood vessel 4, preferably counter to the blood flow, in the direction of larger blood vessels. In this case, a detachment of clot particles during transport through the filter properties of the two elements 1, 2 is avoided. It is possible that the device, in particular if it has penetrated into larger blood vessels, with the aid of a receiving catheter 34, in particular an aspiration tube, from the blood vessel

4 is removed.

In the present invention, not only the receiving element 1 and the distal element 2 are claimed individually, but also in combination. Therefore, all features of the dependent claims back to claim 1 in connection with the imple mentation forms claimed in the recited in the claim 15 dependent claims. LIST OF REFERENCE NUMBERS

Receiving element proximal ring tricher shaped section

Spokes distal opening

Cutting area cylindrical stent structure

distal element a proximal end b distal end a proximal ring b distal ring

Stop funnel-shaped section cylindrical stent structurea contact surface, 26a, 26b spokes

Pointed coaxial opening

actuator

Guide wire

Sliding elements

microcatheter

recording catheter

blood vessel

vessel wall

clot

filter

Claims

claims

1. A device for endovascular treatment, in particular for removing concrements from body vessels, comprising a receiving element (1) and a distal element (2) which are movable from an open position to a closed position relative to each other, wherein the receiving element (1) has a distal opening (14) spaced from the distal element (2) in relation to the distal element (2) and in the open position, characterized in that the distal opening (14) of the receiving element (1) is defined by a proximal end (21a ) of the distal element (2) is closable such that the two elements (1, 2) in the closed position form a substantially closed cavity for receiving an object (42), in particular a concretion.

2. Device according to claim 1, characterized in that the distal element (2) has a stop (23) at the proximal end (21a).

3. A device according to claim 2, characterized geke nnzeichne t that the stop (23) for closing the distal opening (14) of the receiving element (1) is formed.

4. Device according to claim 1, characterized in that the distal element (2) has a rounded profile, at least in the region of the proximal end (21a), in particular in the region of the abutment (23).

5. Device according to at least one of claims 1 to 4, characterized geke n nz eichne t, that the receiving element (1) has a substantially funnel-shaped portion (12).

6. Device according to claim 1, characterized in that the receiving element (1) has a cylindrical stent structure (16) in the region of the distal opening (14).

7. Device according to claim 6, characterized in that the cylindrical stent structure (16) is connected to the funnel-shaped section (12) on a proximal side.

8. Device according to claim 7, characterized in that the funnel-shaped section (12) has spokes (13) which are connected at their proximal ends to a proximal ring (11) and at their distal ends to the cylindrical stent structure (16) wherein the proximal ring (11) has a smaller diameter than the cylindrical stent structure (16).

9. The device according to at least one of claims 1 to 8, characterized in that the receiving element (1) has in a central region a radially outwardly curved shape, in particular with a diameter which is greater than the diameter of the distal opening (14). is.

10. The device according to at least one of claims 1 to 9, characterized gekennz eichnet that the receiving element (1) in the region of the distal opening (14) has an acting in the axial direction cutting region (15).

11. The device according to at least one of claims 1 to 10, characterized in that the distal element (2) is expandable in the radial direction.

12. Device according to at least one of claims 1 to 11, characterized in that the distal element (2) is connected to a guide wire (31) which is essentially axially displaceable relative to the receiving element (1).

13. Device according to claim 11 or 12, characterized in that the distal element (1) in the compressed state forms a tip (28) pointing in the distal direction.

14. Device according to at least one of claims 1 to 13, characterized in that the receiving element (1) and / or distal element (2) each have a filter (50) which is adapted such that in use at least parts of the retained object (42) are retained.

15. Device according to at least one of claims 1 to 14, characterized in that the distal element (2) has a contact surface (25a) for engagement with a vessel wall.

16. The device according to claim 15, characterized in that the contact surface (25a) extends in the axial direction of the distal element (2).

17. Device according to at least one of claims 2 to 16, characterized in that the distal element (2) has a cylindrical stent structure (25) in the area of the abutment (23).

18. Device according to at least one of claims 1 to 17, characterized Porsche Style nz eichnet that an actuating element (3) with a distal end (21b) of the distal element (2) is detachably connected such that the compound is exceeded when passing through the Actuator (3) on the distal end (21b) applied limit force dissolves.

19. The device according to claim 17, characterized in that the actuating element (3) in the position released from the distal end (21b) cooperates with a proximal end (21a) of the distal element (2) such that it acts in the proximal direction Tensile force from the actuating element (3) on the distal element (2) is transferable.

20. A device for endovascular treatment, in particular for removing concrements from body vessels, with a distal element (2) and an actuating element (3) for axial movement of the distal element (2), wherein the distal element (2) has a stop (23 ) adapted to apply an axial force component to an object (42) disposed on the stop (23) in use by the axial movement of the distal element (2), characterized in that the distal element (1) is fitted in such a way that a radial diameter can be increased as a function of the axial force component acting on the object (42).

21. Device according to claim 20, characterized in that the distal element (2) has a spacing between a proximal (211) and a distal (21b) end, which can be changed as a function of the axial force component acting on the object (42) is.

22. Device according to claim 20 or 21, characterized in that the distal element (2) has a substantially funnel-shaped section (24).

23. Device according to claim 20, characterized in that the distal element (2) has a cylindrical stent structure (25) in the region of the abutment (23).

24. The device according to claim 23, characterized in that the cylindrical stent structure (25) is connected to the funnel-shaped section (24) on a distal side.

25. Device according to at least one of claims 22 to 24, characterized in that the funnel-shaped portion (24) has spokes (26, 26b) which at their distal ends with a distal ring (22b) and at their proximal ends with of the cylindrical stent structure (25) are connected, wherein the distal ring (22b) has a smaller diameter than the cylindrical stent structure (25).

26. Device according to at least one of claims 23 to 25, characterized in that the stop (23) comprises spokes (26, 26a) which at their proximal ends with a proximal ring (22a) and at their distal ends with the cylindrical Stent structure (25) are connected, wherein the proximal ring (22a) has a smaller diameter than the cylindrical stent structure (25).

27. Device according to claim 26, characterized in that the spokes (26a) are substantially S-shaped.

28. Device according to claim 20, characterized in that the distal element (2) comprises rings (22a, 22b) arranged at a proximal end (21a) and at a distal end (21b) whose diameter is in the Is essentially the same.

A device according to claim 28, characterized in that the rings (22a, 22b) for forming the distal element (2) are connected by longitudinally extending spokes (26) formed in a central region of the distal element (2) in FIG are curved radially outward.

30. Device according to claim 20, characterized in that the abutment (23) comprises a curvature which extends substantially in the proximal direction.

31. The device according to at least one of claims 20 to 30, characterized in that the distal element (2) is at least partially substantially teardrop-shaped.

32. Device according to at least one of claims 20 to 31, characterized in that the abutment (23) has an opening (29) coaxial with the axis of the distal element (2).

33. The device according to at least one of claims 20 to 32, characterized in that the actuating element (3) is coupled to the distal element (2) at an axial end arranged opposite the stop.

34. The device according to at least one of claims 20 to 33, characterized marked on eichnet that the actuating element (3) comprises a guide wire (31).

35. The device according to at least one of claims 20 to 34, characterized in that the distal element (2) has a filter (50) which is adapted such that in use at least parts of the object (42) are retained