DE102010010848A1 - Medical device for removing concretions from hollow organs of the body - Google Patents

Abstract

The invention relates to a medical device for removing concretions (40) from hollow body organs with a guide catheter (30), a microcatheter (20) arranged longitudinally displaceably in the guide catheter (30) and a receiving element (10) which can be retracted into the microcatheter (20) can be transferred from a compressed state to an expanded state and, in the expanded state, has a distally arranged, axial inlet opening (11) which is adapted for introducing a concrement (40) into the receiving element (10), wherein in the area of the receiving element (10) a negative pressure can be generated in order to move the calculus (40) at least partially into the receiving element (10). The invention is characterized in that the receiving element (10) has a transport channel (12) which, when the receiving element (10) is expanded, extends like a hose between the inlet opening (11) and the microcatheter (20) and when the receiving element is expanded (10) has a cross-sectional diameter which is greater than a diameter of the microcatheter (20), the transport channel (12) comprising a fluid-tight cover (13) which has at least one opening (14) at a proximal end of the transport channel (12) in such a way that the transport channel (12) can be fluidly connected to the guide catheter (30), the guide catheter (30) being or fluidly connected to a suction device in order to generate the negative pressure in the region of the receiving element (10).

Description

The invention relates to a medical device for removing concretions from hollow organs of the body according to the preamble of claim 1. Such a medical device is known for example from WO 2006/031410 A2 known.

A variety of life-threatening, acute illnesses are caused by blood clots or thrombi that form in blood vessels and inhibit blood flow. Due to the blockage of the blood vessel or the impairment of blood flow through the blood clot, downstream tissue areas are no longer sufficiently supplied with nutrients, in particular oxygen. In the affected tissue areas can lead to ischemia, ie the death of tissue cells.

From a medical point of view there is a need to restore the blood flow as quickly as possible, ie to recanalize the blood vessel. On the one hand, this is medically possible, for example with the aid of medicaments for thrombolysis, wherein the thrombus or, in general, the calculus is dissolved on account of the biochemical reaction with the medicament. However, drug-based thrombolysis is limited to a relatively limited group of patients, since strict criteria must be adhered to for the safe use of this therapy. For example, efficient drug therapy of blood clots is successful only in a time window of up to three hours after the occurrence of the event or after the onset of the first symptoms of vascular occlusion.

On the other hand, medical devices are known that allow the removal of blood clots or thrombi or concretions in a mechanical way. Such a device is for example from the WO 2008/088920 A2 known. In the known device is provided to advance a wire element through a catheter in the region of the vessel closure. The catheter is first pushed through the blood clot. The wire member is then held stationary while the catheter is withdrawn. Thereby, the distal end of the wire member comprising a shape memory material is exposed. Due to the shape memory properties, the wire element assumes a previously impressed corkscrew-like shape which engages the blood clot and forms a substantially positive connection with the blood clot. The blood clot fixed in this way to the wire element can then be pulled out of the blood vessel.

The drawback with the known device is that, by pulling the flared distal end of the wire element connected to the blood clot, there is a risk that vessel walls will be damaged or injured by the distal end of the wire element. Furthermore, there is the risk that, when the catheter is pushed through the blood clot, particles will escape which may reach downstream blood vessels and cause further occlusions. Although the mechanical removal of blood clots or generally concrements is usually faster to carry out than a drug lysis therapy. Due to the risk of injury to vessel walls and the risk of additional vascular occlusions, no significant improvement is achieved by such medical devices for mechanically removing blood clots from mortality, for example stroke or apoplexy.

An alternative device for the mechanical removal of blood clots is mentioned in the beginning WO 2006/031410 A2 described. The known device comprises a receiving basket, which is guided in a compressed state within a supply and aspiration catheter to the treatment site. The delivery and aspiration catheter is longitudinally displaceable in a guide catheter. The guide catheter is guided as close as possible to the treatment area, the relatively large cross-sectional diameter of the guide catheter preventing the guide catheter from being introduced directly into the area of the blood clot. The positioning of the receiving basket directly on the blood clot is therefore via the supply and aspiration catheter. For this purpose, the supply and aspiration catheter is led to just before the blood clot and deployed the receiving basket in front of the blood clot. About the supply and aspiration catheter now a negative pressure in the region of the blood clot is generated, which pulls the blood clot in the receiving basket. In order to avoid that blood is sucked out of proximal blood vessels by the generated negative pressure, the guide catheter to a balloon which is expanded prior to the generation of negative pressure to the blood vessel proximal to the clot, in particular in the flow direction before the clot, temporarily fluid-tight close. This has the disadvantage that, during the treatment, ie during the removal of the blood clot, a blood flow into blood vessels which branch off in the vessel section between the balloon at the distal end of the guide catheter and the blood clot is prevented. The supply of nutrients to previously unaffected tissue areas is thus disrupted, which may entail additional health risks for the patient.

In practice, vascular occlusions are usually formed by thrombi in comparatively small and strongly curved blood vessels. To achieve such vascular occlusions with a catheter, there is a need to make the catheter diameter as small as possible. However, a relatively small catheter diameter makes it difficult to aspirate a blood clot. It is therefore known to smash the blood clot in order to remove the blood clot by particles from the blood vessel via the comparatively small aspiration catheter. During the suction treatment, the negative pressure produced initially acts only on one, in particular proximal, side of the blood clot. The fragmentation, however, is effective over the entire thrombus, so that particles can also dissolve on the side of the blood clot facing away from the aspiration catheter. These particles are not detected by the negative pressure of the aspiration catheter and can be washed into smaller blood vessels and lead there to other vascular occlusions.

In the device according to WO 2006/031410 A2 The thrombus can also be pulled out of the blood vessel with the aid of the receiving basket. Analogous to the corkscrew-like device according to WO 2008/088920 A2 there is a risk of injury to the vessel walls. Specifically, the receiving basket or the wire element of the known devices rub during retraction, ie when removing the thrombus, on the vessel wall. The vessel wall can be injured, which can cause a stenosis or new blood clots.

The invention has for its object to provide a medical device for removing concretions from body cavities, which allows an efficient and rapid removal of concrements, whereby the risk of injury to healthy tissue is reduced and the formation of additional vessel blockages is avoided.

This object is achieved by the subject-matter of claims 1 and 13.

The invention is based on the idea of specifying a medical device for removing concretions from body cavities with a guide catheter, a microcatheter arranged longitudinally displaceably in the guide catheter and a receiving element which can be retracted into the microcatheter. The receiving element is convertible from a compressed state to an expanded state. In the expanded state, the receiving element has a distally arranged, axial inlet opening, which is adapted for introducing a concretion in the receiving element. In the region of the receiving element, a negative pressure can be generated in order to move the concrement at least partially into the receiving element. The receiving element further has a transport channel, which extends like a tube between the inlet opening and the microcatheter in the expanded state of the receiving element and in the expanded state of the receiving element has a cross-sectional diameter which is larger than a diameter of the microcatheter. The transport channel comprises a fluid-tight cover, which has at least at such an opening at a proximal end of the transport channel that the transport channel can be fluid-connected to the guide catheter. The guide catheter is fluidly connected to a suction device or fluid-connectable to generate the negative pressure in the region of the receiving element.

The invention is based on the idea of providing the receiving element with an expandable transport channel which bridges the distance from the concretion to the guide catheter in the concretely closed vessel. In this case, the transport channel is formed like a tube. The transport channel forms in the expanded state, a flexible tube with a fluid-tight envelope, which is fluidly connected to the guide catheter. The guide catheter can be connected or connected to a suction device, so that a negative pressure for sucking in the concretion can be generated via the guide catheter through the at least one opening in the cover of the transport channel in the transport channel or generally in the receiving element.

In general, in the invention, a separation of functions is achieved, wherein the guide catheter directs the negative pressure generated in the suction device to the receiving element, while the micro-catheter, which is guided within the guide catheter, causes the supply of the compressed receiving element to the treatment site. Through this separation of functions is advantageously achieved that the suction line, namely the guide catheter, may have a relatively large cross-sectional diameter, so that an efficient extraction performance is achieved. At the same time, the microcatheter can have a relatively small cross-sectional diameter, so that the receiving element can be guided into relatively small blood vessels. Furthermore, due to the fluid-tight covering, a temporary interruption of the blood flow, for example by a balloon in the region of the distal end of the guide catheter, can be dispensed with. The fluid-tight cover causes the negative pressure within the body cavity to be effective mainly between the inlet opening and the concretion. For this purpose, it is advantageous if a distal end of the receiving element in the expanded state seals against a vessel wall of the body cavity. An impairment of the supply of nutrients, in particular oxygen, in branching body cavities between the concretion and the guide catheter is avoided with the construction according to the invention. In particular, the transport channel can advantageously comprise a cross-sectional diameter which is smaller than the cross-sectional diameter of the hollow body organ, so that between the transport channel and the hollow body organ an annular space is formed, in which a body fluid can flow. However, it is not excluded that the transport channel has a cross-sectional diameter such that the transport channel rests against a vessel wall of the hollow body organ.

Another advantage of the device according to the invention is that during the suction or the aspiration-releasing concretion particles led through the transport channel to the comparatively large-lumen guide catheter who the. The calculus particles are thus reliably removed from the body cavity. Since the cross-sectional diameter of the entire suction line formed by the guide catheter and the receiving element is comparatively large, concretion particles are prevented from blocking the suction line. This ensures that the concretion in the body cavity constantly a negative pressure acts. Due to the constantly acting negative pressure, it is avoided that detaching concretion particles move into branching body cavities and lead there to further closures or blockages.

The transport channel thus bridges the distance between the guide catheter and the concretion, which is sucked through the transport channel in the guide catheter. The receiving element can therefore be kept stationary in the device according to the invention. Retraction of the receiving element to remove the calculus is not required. Appropriately, to remove the receiving element after the treatment rather the microcatheter is pushed over the receiving element in order to compress the receiving element or to convert it into the compressed state. Therefore, a relative movement does not take place between the receiving element and the hollow body organ, but between the receiving element and the microcatheter. The risk of injuring the hollow body organ, in particular vessel walls of the hollow body organ, is thus reduced.

In a preferred embodiment of the medical device according to the invention, a guide wire is provided, which is connected to the proximal end of the receiving element. The guidewire may be longitudinally displaceable within the microcatheter. The guidewire facilitates handling of the receiving element. In particular, a user can guide the receiving element by means of the guide wire on the one hand through the microcatheter to the treatment site. On the other hand, the guide wire allows the stationary fixation of the expanded receiving element, so that the receiving element is retractable by a relative movement between the guide wire and the microcatheter in the microcatheter. Specifically, the receiving element can be held stationary by means of the guide wire from outside the body to be treated, while the microcatheter is pushed in the distal direction over the receiving element. The receiving element expanded in the body cavity can thus be converted into the compressed state and placed in the microcatheter.

Generally, it is advantageous to hold the expanded receiving member stationary after suction of the blood clot and to push the microcatheter over the receiving member to compress the receiving member. This avoids that the expanded receiving element is moved in the hollow body organ. The risk of injury to the body hollow organ is reduced in this way. Since the microcatheter can have a comparatively small cross-sectional diameter, the device can also be advantageously used for removing concrements from comparatively small hollow organs of the body, for example cerebral blood vessels.

The receiving element may have a net-like support structure. The reticulated support structure can advantageously ensure a radial stability of the receiving element, in particular of the transport channel, in the expanded state, so that the negative pressure acting within the receiving element does not lead to a collapse of the receiving element or the transport channel.

The reticulated grid structure advantageously comprises a wire mesh. By the wire mesh, or a braided grid structure or a mesh, on the one hand sufficient radial stability of the receiving element is achieved and on the other hand ensures a comparatively high flexibility of the receiving element, so that the receiving element can follow the course of the hollow body organ.

The wire mesh preferably has a braiding angle which is at least 30 °, in particular at least 40 °, in particular at least 45 °, in particular at least 50 °, in particular at least 55 °, in particular at least 60 °. By a comparatively large braiding angle, a high radial force is provided, so that collapse of the receiving element, for example due to of the negative pressure, is avoided. Specifically, a sufficient radial stability is provided by the aforementioned braid angle, so that the receiving element, in particular the transport channel, withstands the negative pressure acting within the receiving element.

Alternatively, the wire mesh may have a braiding angle which is at most 70 °, in particular at most 60 °, in particular at most 50 °, in particular at most 45 °, in particular at most 40 °, in particular at most 30 °, in particular at most 20 °. Such braiding angles allow a high flexibility of the receiving element, so that the receiving element adapts well to vessel curvatures. The receiving element can be used in this way in particularly highly curved vessel sections. Furthermore, the effect of "foreshortening", ie the shortening of the lattice structure during expansion, is reduced with the aforementioned braiding angles, thus facilitating the accurate positioning of the receiving element.

In the case of a wire mesh, the wire elements which overlap or intersect in intersection areas each have an acute angle with respect to a straight line extending in the axial direction of the receiving element. This acute angle, which is formed between the straight line extending in the axial direction and a wire element, is referred to as a braid angle. The braiding angle in the context of the present application thus relates to the angle between a wire element and a projection of the axis of rotation of the hose-like receiving element in a wall plane in which the wire element extends. The determination of the braiding angle takes place in the idle state or expanded state of the receiving element. Due to the geometric displacement of the wire elements upon compression of the receiving element, the angle between the axially extending straight line and the wire elements at the transition from the expanded to the compressed state changes. The braiding angle refers to the angle provided during braiding of the wire mesh between the straight line extending in the axial direction and the wire elements. The braiding angle therefore essentially corresponds to the angle between the straight line running in the axial direction and a wire element in the expanded state of the receiving element.

In a further preferred embodiment of the medical device according to the invention, the receiving element in the expanded state comprises a radially expanded, in particular basket-like, suction, which is connected to the transport channel. The suction section may have a fluid-tight cover. In particular, the fluid-tight cover may extend into the suction section. The suction section can be expandable such that the suction section seals in the expanded state of the receiving element against an inner surface or a wall of the hollow body organ. It is thus achieved that the negative pressure guided through the guide catheter and the suction element is limited in its effectiveness with respect to the hollow body of the body to the area between the suction section and the concretion. This means that between the suction section and the calculus a delimited aspiration of the hollow body organ is formed, which is acted upon by the negative pressure. The delimited aspiration space is fluidly connected to the suction device via the transport channel and the guide catheter. Preferably, the suction section comprises the axial inlet opening of the receiving element. The suction portion may be funnel-shaped. Specifically, the inlet opening may have a cross-sectional diameter which is larger than a cross-sectional diameter of the transport channel. The suction section can form a flowing transition between the inlet opening and the transport channel. Due to the different cross-sectional diameter between the inlet opening and the transport channel ensures that on the one hand the aspiration between the inlet opening and the concretion fluid-tight demarcated and on the other hand, a supply of nutrients or body fluids in body hollow organs, which branch off between the inlet opening and the guide catheter, is guaranteed. It is provided in particular that the transport channel has a cross-sectional diameter which is smaller than the cross-sectional diameter of the hollow body member, in which the transport channel is arranged in use. In this way, an annular space is formed between the hollow body organ and the transport channel, which allows the supply of body fluids, in particular blood, in branching body hollow organs.

In a further preferred embodiment, the cover of the transport channel in use, in particular in the expanded state of the receiving element, fluid-tight with an inner surface of the guide catheter in abutment can be brought. The cover of the transport channel can seal in the expanded state of the receiving element against the inner surface of the guide catheter, so that a continuous fluid-tight suction line is provided from the guide catheter to the inlet opening in the expanded state of the receiving element. In particular, the sealing of the cover of the transport channel with the inner surface of the guide catheter ensures that the negative pressure transmitted by the guide catheter from the suction device is conducted directly into the receiving element, in particular the transport channel. A pressure loss at the junction between the Guide catheter and the receiving element is thus avoided.

The transport channel may have a length which is at least 4 times, in particular at least 6 times, in particular at least 8 times, in particular at least 10 times, in particular at least 15 times, in particular at least 20 times, in particular at least 25 times, in particular at least 30 times, in particular at least 40 times, in particular at least 50 times, in particular at least 70 times, in particular at least 100 times, corresponds to an inner diameter of the guide catheter.

Preferably, the transport channel or the receiving element has an absolute length which is at least 5 cm, in particular at least 7 cm, in particular at least 10 cm, in particular at least 15 cm, in particular at least 20 cm. The aforementioned values essentially correspond to the distance of the guide catheter from a concretion, in particular a thrombus in a blood vessel, this distance being predetermined by the anatomy of the blood vessels. Specifically, due to the relatively large cross-sectional diameter, a guide catheter can be led to a calculus at most up to 5 cm. The transport channel or the receiving element bridges the distance between concretion and guide catheter.

The guide catheter may have an inner diameter which is at least 0.8 mm, in particular at least 1.0 mm, in particular at least 1.2 mm, in particular at least 1.4 mm, in particular at least 1.5 mm, in particular at least 1.6 mm, in particular at least 1.8 mm, in particular at least 2.0 mm, in particular at least 2.2 mm, in particular at least 2.5 mm, in particular at least 3.0 mm. Alternatively or additionally, the guide catheter may have an inner diameter which is at most 2.4 mm, in particular at most 2.2 mm, in particular at most 2.0 mm, in particular at most 1.8 mm, in particular at most 1.6 mm, in particular at most 1.4 mm, in particular not more than 1.2 mm, in particular not more than 1.0 mm.

The appropriate values for the inner diameter of the guide catheter are dependent on the respective site of use of the medical device and are selected by the person skilled in the art in accordance with the medical guidelines. It has been found that an inner diameter of about 1.5 mm of the guide catheter is sufficient, for example, to efficiently aspirate a thrombus with a cross-sectional diameter of about 3 mm. By smaller inner diameter (with the same wall thickness), however, the feedability of the guide catheter can be increased.

In a further preferred embodiment of the medical device according to the invention, a distal holding element is provided, which can be converted from a compressed state into an expanded state. The distal retaining element is retractable into the microcatheter. The holding element is arranged in the expanded state spaced from the inlet opening of the receiving element. The retaining element can advantageously be used to effectively retain concretion particles which detach on the side of the concretion facing away from the negative pressure. The risk of a distal embolism, ie a vascular occlusion in downstream vascular areas, is thus effectively avoided.

The distal holding element can be connected to the receiving element and / or the guide wire. In particular, the distal holding element can be actuated by the guide wire. Alternatively, the distal support member may be connected or connectable to a separate actuator. The distal holding element can be used in this way to push a concretion mechanically into the receiving element. It is therefore possible that the holding element performs a dual function, namely on the one hand to retain peeling concretion particles and on the other hand to move the concretion mechanically into the receiving element. The mechanical movement of the receiving element can be carried out additionally or separately for suction through the guide catheter and the receiving element. Instead of a mechanical movement of the concretion by the holding element and a hydraulic movement can be effected via the holding element. For example, the holding element can be fluidly connected to the guide catheter or the suction device, so that a negative pressure can be generated in the region of the holding element, specifically between the holding element and the concretion. Advantageously, between the holding element and the concretion, an overpressure can be generated, which drives the concretion into the inlet opening of the receiving element.

According to a secondary aspect, the invention is based on the idea of specifying a medical device for removing concretions from hollow organs of the body with a guide catheter, a micro catheter longitudinally displaceable in the guide catheter and a receiving element retractable into the microcatheter, which can be converted from a compressed state into an expanded state is and has a distally disposed, axial inlet opening in the expanded state. The axial inlet opening is adapted for introducing a concretion in the receiving element. The receiving element has a transport channel, which extends like a tube between the inlet opening and the microcatheter in the expanded state of the receiving element and in the expanded state of the receiving element has a cross-sectional diameter which is larger than a diameter of the microcatheter. The transport channel has at least one opening at a proximal end in such a way that the transport channel can be connected to the guide catheter. Distal to the receiving element, a holding element is arranged, which is connected to an actuating element such that the holding element is movable relative to the receiving element in order to introduce a concretion in the axial inlet opening.

The retaining element is adapted to fix the concretion and to move into the inlet opening. In this case, the retaining element can grasp or fix the concrement both laterally, distally or proximally. In general, the holding means allows a mechanical movement of the concretion into the inlet opening of the receiving element. Alternatively, a pressure, in particular a fluid pressure, can be transmitted to the concretion via the holding element, which causes the movement of the concretion into the receiving element. The actuator may be, for example, a guide wire. The actuator preferably extends through the microcatheter or guide catheter. The holding element can be retractable both in the microcatheter, so also in the guide catheter.

By the transport channel is avoided not to move the receiving element in the expanded state within the body hollow organ. The inclusion or encapsulation of the calculus takes place essentially by a movement of the retaining element. This reduces the risk of injury to the vessel walls.

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

1 to 3 in each case a side view of a medical device according to the invention according to a preferred embodiment in different stages of the discharge of the receiving element from the microcatheter;

4 a side view of a medical device according to the invention according to a preferred embodiment in use; and

5 a longitudinal section through a medical device according to the invention according to a preferred embodiment.

The following definitions apply to all embodiments mentioned in the present application:
In the context of the present application, the term pressure does not only mean positive pressures (overpressure), but explicitly also negative pressures (negative pressure). In this case, an overpressure is a pressure which is higher than the pressure prevailing in the vessel. Correspondingly, a negative pressure is a pressure that is lower than the pressure prevailing in the vessel, in particular lower than a pressure within a vessel section that is distal to the concretion 40 is arranged. Due to the pressure difference between the vessel sections before (proximal) and behind (distal) the calculus 40 becomes the desired movement of the calculus 40 causes.

The invention is particularly suitable for removing clots or thrombi from blood vessels. Although the invention is described below using the example of the removal of thrombi, other possible uses of the device, which relate to the removal of concretions or objects from body cavities, are also encompassed by the invention.

The space designations or directions, in particular the names distal and proximal, refer to the position of the user who operates the device. Distally arranged objects are accordingly arranged further away from the user or operator of the device with respect to a proximally arranged object.

In the 1 to 3 are successive stages during the discharge of the receiving element 10 from the microcatheter 20 shown. The receiving element 10 is completely within the microcatheter before discharge 20 arranged. The receiving element 10 indicates the arrangement within the microcatheter 20 the compressed state. The following description of the structure of the medical device relates essentially to the at least partially expanded state of the receiving element 10 , which is during the dismissal of the receiving element 10 from the microcatheter 20 established.

The receiving element 10 has a substantially rotationally symmetrical shape in the expanded state. In a distal end region of the receiving element 10 is a suction section 15 formed, which has a substantially funnel-like shape. The intake section 15 opens in the distal direction and limits an axial inlet opening 11 of the receiving element 10 , The Funnel shape of the suction section 15 is preferably adapted such that the inlet opening 11 over the entire cross-sectional area of a blood vessel 45 into which the receiving element 10 is introduced and expanded therein extends. Preferably, the funnel-shaped suction section seals 15 against the vessel wall of the blood vessel 45 from.

To the intake section 15 closes in the proximal direction of a transport channel 12 at. The transport channel 12 is with the intake section 15 firmly connected. In particular, the transport channel 12 with the intake section 15 formed in one piece. The transition between the intake section 15 and the transport channel 12 may be formed substantially continuously or fluently.

The transport channel 12 is as part of the receiving element 10 from a compressed state to an expanded state. The transport channel 12 has a tubular shape at least in the expanded state. In the expanded state, the transport channel 12 a cross-sectional diameter greater than a cross-sectional diameter in the compressed state, in particular greater than a cross-sectional diameter of the microcatheter 20 is. Preferably, the transport channel 12 in the expanded state, a cross-sectional diameter which is smaller than the inner diameter of the blood vessel 45 is. In this way, between the transport channel 12 and the blood vessel 45 or, in general, the hollow body of the body is kept free from an annular space, so that body fluid, in particular blood, flows unhindered from proximal to distal at least into the area of the suction section 15 can flow. A supply of branching vessels with blood or nutrients is thus ensured during the treatment, ie during the removal of the concretion or concretely a thrombus from a blood vessel.

The transport channel 12 extends to a proximal end of the receiving element 10 , wherein the receiving element 10 a rejuvenation 16 forms, which limits the receiving element 10 at the proximal end axially. The rejuvenation 16 is with a guidewire 21 connected through the microcatheter 20 extends and within the microcatheter 20 is axially displaceable ( 5 ). The connection between the receiving element 10 , especially the rejuvenation 16 , and the guidewire 21 can be designed detachable. Preferably, the receiving element 10 , especially the rejuvenation 16 , with the guide wire 21 firmly connected or formed in one piece.

In general, the receiving element 10 comprise a net-like support structure. The support structure may be formed substantially stent-like. The support structure may comprise a laser-cut lattice structure or a braided wire lattice. The laser-cut lattice structure is preferably formed from a tubular raw material. It is also possible that the laser-cut lattice structure is made of a flat raw material, which after the structuring in a cylindrical or generally rotationally symmetrical shape transferred, in particular bent, is.

Preference is given to the use of a braided wire mesh or a grid mesh for the receiving element 10 , In this case, one or more wire elements are substantially spirally about a common longitudinal axis, in particular the longitudinal axis of the rotationally symmetrical shape of the receiving element 10 wound. At least two wire elements or two wire sections of a wire element are wound in opposite directions about the longitudinal axis and form at least one crossing point. The oppositely wound wire elements intersect, with one wire element extending over the other. A type of braid in which one wire element at a crossing point crosses a further wire element is called a 1-over-1 weave. It is also possible for a wire element to cross over two further wire elements in a crossing point, so that a 1-over-2 weave is formed. Further possible types of braiding are, for example, a 1-over-3 braiding, a 1-over-4 braiding, a 2-over-1 braiding, a 2-over-2 braiding, a 3-over-1 braiding, 3 braids 2-plait or 4-over-2 plait.

The braided wire mesh or mesh can both the suction section 15 , as well as the transport channel 12 support. The receiving element 10 can have a total of a support structure of a grid mesh. This means that the intake section 15 , the transport channel 12 and the rejuvenation 16 have the grid mesh. It is also possible that the grid mesh or at least one or more wires of the grid mesh the guide wire 21 form. The mesh may be at the proximal end of the receptacle 10 , ie in the area of rejuvenation 16 , to the longitudinal axis of the receiving element 10 towards be radially merged and as a guidewire 21 continue. The guidewire 21 may be formed by at least one wire element, which is also the grid of the receiving element 10 forms.

At least the transport channel 12 of the receiving element 10 has a fluid-tight cover 13 on. The transport channel 12 is in particular with a cover 13 or provided with a coating or a Covering, with the receiving element 10 may be formed integrally or in one piece. The cover 13 forms a fluid-tight wall of the transport channel 12 , The cover 13 may be prepared by sputtering or another coating method as a cantilevered support structure. Preferably, the cover comprises 13 a plastic, in particular polyurethane (PU). The cover 13 can firmly with the net-like support structure or the mesh of the transport channel 12 be connected. It can cover 13 both on an inner surface of the transport channel 12 , as well as on an outer surface or an outer circumference of the transport channel 12 be arranged. The cover 13 can be over the entire recording element 10 extend or the receiving element 10 only partially cover, especially in the area of the transport channel 12 , Preferably, the transport channel 12 completely with the cover 13 Mistake. The transport channel 12 forms in particular a flexible hose which is completely closed fluid-tight on the circumference. The transport channel 12 has in the expanded state substantially a hollow cylindrical shape with a flexible peripheral wall. The peripheral wall is completely covered fluid-tight. The cover 13 is made of a fluid-tight material, which is sufficiently tight, to provide a pressure difference between the inside and outside of the cover 13 unbearable.

The cover 13 can also be about the entire recording element 10 extend, in particular via the intake section 15 , Overall, the receiving element 10 have a cup-shaped shape, which is completely covered fluid-tight. The cup-like shape is in the region of the suction section 15 widened. The widening, in particular cup-like widening, of the receiving element 10 in the area of the intake section 15 or the inlet opening 11 prevents collapse of the blood vessel 45 , The intake section 15 thus fulfills a support function for the blood vessel 45 , This can be the intake section 15 provide an increased radial force, for example by a mesh with a relatively large braiding angle. Preferably, the intake section comprises 15 the cover 13 so that the intake section 13 against the vessel wall of the hollow body organ or the blood vessel 45 covering fluid-tight. Alternatively, the intake section 15 have a free grid structure.

In this context, it should be noted that the term fluids in the context of the present application refers not only to liquids, but also to gases.

At the proximal end of the receiving element 10 , in particular in the field of rejuvenation 16 , points the cover 13 at least one opening 14 on. The opening 14 may extend substantially axially. That means the cover 13 forms a terminal edge, which is in the area of rejuvenation 16 in the circumferential direction around the receiving element 10 extends. The axial opening 14 may be the opening of the hollow cylindrical shape of the transport channel 12 at the proximal end of the transport channel 12 or at the distal end of the taper 16 correspond. That means the cover 13 over the transport channel 12 until rejuvenation 16 can extend. At least partially has rejuvenation 16 no cover 13 on. Rather, at least part of the rejuvenation involves 16 a free grid structure, in particular a free grid mesh. Alternatively, the cover may be 13 in the area of rejuvenation 16 extend, with the cover 13 at least one opening 14 has, extending along the circumference of the receiving element 10 or the rejuvenation 16 extends. The opening 14 can be aligned laterally or radially. The rejuvenation 16 may substantially have a hollow cone-like shape. The opening 14 may be formed in the conical surface which passes through the cover 13 covered or covered. The conical surface can also be interrupted at least in sections, so that in the region of the taper 16 a frusto-conical recess or opening 14 is formed. A perimeter strip of the cover 14 can be in the field of rejuvenation 16 be released, so that at least in sections, the support structure of the rejuvenation 16 or in general of the receiving element 10 exposed and thus openings 14 are provided.

As in 3 shown, it is provided that the rejuvenation 16 of the receiving element 10 in completely discharged condition within a guide catheter 30 is arranged. The receiving element 10 is in the discharged state partially within and partially outside the guide catheter 30 arranged. The intake section 15 and the transport channel 12 are outside the guide catheter 30 arranged. The rejuvenation 16 is, however, within the guiding catheter 30 arranged. The cover 13 extends at least partially into the area of the rejuvenation 16 and seals with a distal axial end of the guide catheter 30 fluid-tight, as detailed in 5 shown. The opening 14 or the plurality of openings 14 in the field of rejuvenation 16 provide fluid communication between the guide catheter 30 and the transport channel 12 or generally the receiving element 10 ago.

The guiding catheter 30 has substantially a cross-sectional diameter which is sufficient to efficient aspiration, ie suction, a concretion 40 , in particular thrombus. The guiding catheter 30 includes a larger cross-sectional diameter than the microcatheter 20 that inside the guiding catheter 30 is guided longitudinally displaceable. Within the microcatheter 20 is the guidewire 21 guided longitudinally displaceable. The receiving element 10 is also within the microcatheter in the compressed state 20 arranged.

The receiving element 10 can be in the field of rejuvenation 16 at least one separating element 17 include, as in 5 indicated. The separating element 17 may be formed, for example, by at least one wire element of the grid mesh. The separating element 17 is preferably between two openings 14 formed or thwarts an opening 14 in the cover 13 , The separating element 17 may include a cutting area. In particular, the separating element 17 having a cutting edge substantially in the direction of the transport channel 12 is aligned. The separating element 17 is adapted such that a calculus 40 or a thrombus via the transport channel 12 in the guide catheter 30 is sucked or aspirated, in the area of rejuvenation 16 is cut or isolated. In this way the aspiration performance is increased. The separating element 17 can be essentially in the circumferential plane of the rejuvenation 16 extend. Alternatively, it can be provided that in the area of rejuvenation 16 radially inwardly directed separating elements 17 are arranged. The separating elements 17 can be aligned in a cross shape. For example, the separating elements 17 in a cross-sectional plane of the rejuvenation 16 be arranged in a wheel spoke.

In a further preferred embodiment according to 4 the medical device additionally has a retaining element 50 distally spaced from the entrance opening 11 of the receiving element 10 is arranged. The holding element 50 has a umbrella-like or cap-like shape with a tip 51 which extends in the distal direction. The holding element 50 is with an actuator 52 connected. The actuator may be through the receiving element 10 and the microcatheter 20 extend and be operated from outside the body or extracorporeal. In particular, the actuating element can be displaceable in the axial direction, so that the distance of the retaining element 50 from the entrance opening 11 is adjustable. By actuating the actuating element, the expanded holding element 50 be pulled in the proximal direction, so that a between the receiving element 10 and the holding element 50 arranged calculus 40 mechanically in the receiving section 10 is pulled. The mechanical inclusion of the calculus 40 in the receiving element 10 may be due to the aspiration, ie the negative pressure generated in the extracorporeal suction device and via the guide catheter 30 and the receiving element 10 proximal to the calculus 40 acts, be supported.

The holding element 50 can also with the receiving element 10 , in particular the intake section 15 be connected. For example, it is possible to produce the device as a whole from a grid mesh, wherein the wire elements between the receiving element 10 and the holding element 50 are merged and a connection in the form of a strand 52 form. The receiving element 10 and the holding element 50 are preferably positioned such that the strand 52 at the height of the thrombus or concrements 40 is arranged. In general, the retaining element 50 a support structure, which may include a wire mesh. The support structure may also be analogous to the construction of the receiving element 10 comprise a laser-cut lattice structure. The holding element 50 can also have a cover 13 exhibit. The cover 13 of the holding element 50 may have a structuring, in particular a pore structure. The holding element 50 can be sieve-shaped. Generally, the retaining element 50 be designed so fluid permeable, that on the one hand, a body fluid, in particular blood, the retaining element 50 can flow through and on the other hand concretion particles are retained.

The receiving element 10 and / or the retaining element 50 may have marker elements. The marker elements preferably comprise a radiopaque material, so that the position of the receiving element 10 or of the retaining element 50 under X-ray control are controllable. This applies to all embodiments.

The receiving element 10 and / or the microcatheter 20 and / or the guiding catheter 30 may have a stop. Preferably, the receiving element comprises 10 at the proximal end, especially in the area of rejuvenation 16 or between the rejuvenation 16 and the transport channel 12 or at a proximal end of the transport channel 12 , a stop, leaving the receiving element 10 This is prevented completely from the guide catheter 30 withdraw. In this way, the rejuvenation 16 inside the guide catheter 30 held. The microcatheter 20 may also have a stop that with a stopper counterpart within the guide catheter 30 interacts with the displaceability of the microcatheter 20 inside the guide catheter 30 to limit. This will ensure that the rejuvenation 16 be arranged between the distal axial end of the guide catheter and the distal axial end of the microcatheter and the transport channel 12 with the guide catheter 30 fluidly connected.

The following describes the mode of operation of the medical device:
To remove a calculus 40 , Specifically, a thrombus, first, the guiding catheter 30 , preferably with the aid of a guide wire 21 into a vessel section of the body cavity or blood vessel to be treated 45 led by the concrements 40 is arranged remotely. The flow cross-section of the vessel portion in which the guide catheter 30 is usually larger than the flow cross-section of the vessel portion, by the concretion 40 is closed. Specifically, the relatively large cross-sectional diameter of the guide catheter prevents 30 advancing the guide catheter 30 into the relatively small blood vessel 45 that by the calculus 40 is closed. To avoid the guiding catheter 30 the blood vessel 45 closes or blocks blood flow, becomes the guiding catheter 30 further away from the calculus 40 positioned in a vessel portion having a larger cross-sectional diameter than the guide catheter 30 , Due to the anatomical conditions of the blood vessel system becomes the guiding catheter 30 preferably about 5 cm to 20 cm in front of the calculus 40 or proximal to the calculus 40 positioned.

Through the guide catheter 30 then the microcatheter 20 to the proximal end of the calculus 40 or thrombus. In this case, a guide aid (not shown), in particular an additional guide wire, can be used, wherein the guide aid initially through the guide catheter 30 to the calculus 40 is pushed. About the guide tool becomes the microcatheter 20 to the calculus 40 pushed and then removed the guide tool. In a next step, the receiving element 10 to the distal tip of the microcatheter 20 guided. This is the receiving element 10 through the guide wire 21 that with the receiving element 10 connected through the microcatheter 20 pushed. Once the receiving element 10 the tip of the microcatheter 20 or the proximal end of the calculus 40 has reached, the microcatheter 20 pulled back in the proximal direction. The receiving element 10 is done simultaneously by extracorporeal fixation of the guidewire 21 kept stationary. It is also possible to use the guide wire 21 Slightly move in the distal direction during expansion to shorten the receiving element 10 during the expansion ("foreshortening"). This avoids that the receiving element 10 Rubs on the vessel wall and causes injury. By removing the microcatheter 20 becomes the receiving element 10 dismiss. That means the receiving element 10 successively from the compressed state to the expanded state. In the process, the intake section first unfolds or expands 15 including the inlet 11 ( 1 ). The intake section 15 seals against the vessel wall of the blood vessel 45 from. When the intake section 15 preferably a fluid-tight cover 13 has, forms the sealing against the vessel wall suction 15 with the calculus 40 that the blood vessel 45 closes, a closed aspiration room.

In the further course of retraction of the microcatheter 20 becomes the transport channel 12 of the receiving element 10 released as in 2 seen. The transport channel 12 is converted to the expanded state. Due to the reticulated support structure or the mesh braid and the flexible, relatively thin, in particular film-like, cover 13 , points the transport channel 12 a high flexibility and adapts to the course of the body hollow organ or blood vessel 45 at. In 2 is good to see that the receiving element 10 , in particular the transport channel 12 , the microcatheter 20 and the guiding catheter 30 essentially telescopically slide into each other or are displaced. The microcatheter 20 is withdrawn until the rejuvenation 16 is disposed between the distal end of the microcatheter and the distal axial end of the guide catheter, the opening 14 in the rejuvenation 16 a fluid connection between the guide catheter 30 and the transport channel 12 manufactures.

The aspiration is through the guide catheter 30 accomplished. The thrombus or the calculus 40 is through the receiving element 10 Aspirates and then goes into the guide catheter 30 above. Specifically, the guiding catheter 30 at a proximal end, in particular extracorporeal, connected to a suction device or connectable. By the suction device, a negative pressure is generated by the guide catheter 30 , the opening 14 in the rejuvenation 16 , the transport channel 12 and the suction section 15 until it acts in the aspiration space between the expanded intake section 15 and the calculus 40 is trained. Under the influence of the negative pressure becomes the calculus 40 in the intake section 15 drawn. The sucked calculus 40 is then via the transport channel 12 to the guide catheter 30 sucked over the opening 14 in the cover 13 with the transport channel 12 fluidly connected. The calculus 40 is over the guide catheter 30 removed from the body. This process continues until complete removal of the thrombus or calculus 40 continued.

In 3 is the receiving element 10 in the fully released condition, ie in use. In use, which is described in the context of the application as a fully released state, is the receiving element 10 completely outside the microcatheter 20 arranged. Here is the distal end of the microcatheter 20 and thus also the proximal end of the receiving element 10 , especially the rejuvenation 16 , inside the guide catheter 30 arranged. The cover 13 of the transport channel 12 seals against an inner surface of the guide catheter 30 so that a fluid channel is formed extending from the extracorporeally arranged suction device via the guide catheter 30 and the transport channel 12 into the intake section 15 or to the calculus 40 extends. The fluid connection between transport channel 12 and guide catheter 30 is in 5 clearly visible.

When the blood vessel 45 is free, so the calculus 40 is completely removed, the receiving element 10 in the microcatheter 20 withdrawn, wherein the receiving element 10 again takes the compressed state. To avoid vessel injury, the construction of the receiving element allows 10 that the microcatheter 20 in the distal direction over the receiving element 10 is pushed. A movement of the receiving element 10 in the proximal direction, which can lead to injury to the vessel wall, is thus avoided.

The microcatheter 20 can be inside the guide catheter 30 be centered as well as decentered. For example, the microcatheter 20 , as in 5 shown, laterally along an inner surface of the guide catheter 30 slide. The same essentially applies to the guide wire 21 which also centered or decentered within the guiding catheter 30 and / or the microcatheter 20 can be arranged.

• – Der gesamte Thrombus wird aspiriert, selbst wenn der Thrombus aus mehreren Bereichen besteht. Eine distale Embolie, also ein Gefäßverschluss distal gelegener Körperhohlorgane, wird vermieden.
• – Abzweigende Gefäße bleiben während der Behandlung offen (Ringraum)
• – Das Aufnahmeelement 10 wird nicht entlang der Gefäßwand gezogen, sondern der Mikrokatheter 20 darüber gestülpt, so dass Verletzungsgefahr für Gefäßwände reduziert ist.

In summary, the medical device offers the following advantages:

• - The entire thrombus is aspirated, even if the thrombus consists of several areas. A distal embolism, ie a vascular occlusion of distal body organs, is avoided.
• - Branching vessels remain open during treatment (annulus)
• - The receiving element 10 is not pulled along the vessel wall, but the microcatheter 20 slipped over so that the risk of injury to vessel walls is reduced.

The above-described functional elements, in particular the receiving element 10 and the holding element 50 , can be prepared by sputtering and photolithographic etching. In particular, by the recently developed manufacturing techniques for producing self-supporting, in particular sputtered functional elements can be very thin wall thicknesses achieved. This applies to both cylindrical and planar functional elements, which are converted into cylindrical shape in use. It is also possible to produce the wall thicknesses described above by interweaving correspondingly thin wire elements. As materials for the thin-film technology as well as wire materials are nickel-titanium alloys, chromium-cobalt alloys, such as Phynox, Elgiloy, stainless steels (LB. 316 LVM), platinum and / or platinum alloys, especially platinum-iridium alloys, Magnesium and / or magnesium alloys and tungsten or tungsten alloys, in particular titanium-tungsten alloys or tungsten-rhenium alloys in question. In general, materials such as magnesium, iron or tungsten and their alloys can be used, which have bioadsorbable properties. It is also possible to use plastic filaments such as Dynema to form the support structure. The thin-walled functional elements described can also be made of other plastics, in particular polyurethane or bioresorbable plastics.

LIST OF REFERENCE NUMBERS

10

receiving element

11

inlet opening

12

transport channel

13

cover

14

opening

15

suction

16

rejuvenation

17

separating element

20

microcatheter

21

guidewire

30

guide catheter

40

concretion

45

blood vessel

50

retaining element

51

top

52

strand

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2006/031410 A2 [0001, 0006, 0008]
• WO 2008/088920 A2 [0004, 0008]

Claims (13)

Medical device for removing concrements ( 40 ) from hollow organs of the body with a guide catheter ( 30 ), one in the guide catheters ( 30 ) longitudinally displaceable microcatheter ( 20 ) and one in the microcatheter ( 20 ) retractable receiving element ( 10 ), which is convertible from a compressed state to an expanded state and in the expanded state, a distally disposed, axial inlet opening ( 11 ), which is used for introducing a calculus ( 40 ) in the receiving element ( 10 ), wherein in the region of the receiving element ( 10 ) a negative pressure is generated to the concretion ( 40 ) at least partially into the receiving element ( 10 ), characterized in that the receiving element ( 10 ) a transport channel ( 12 ), which in the expanded state of the receiving element ( 10 ) hose-like between the inlet opening ( 11 ) and the microcatheter ( 20 ) and in the expanded state of the receiving element ( 10 ) has a cross-sectional diameter which is greater than a diameter of the microcatheter ( 20 ), the transport channel ( 12 ) a fluid-tight cover ( 13 ), which at a proximal end of the transport channel ( 12 ) at least one opening ( 14 ) such that the transport channel ( 12 ) with the guide catheter ( 30 ) is fluid-connectable, wherein the guide catheter ( 30 ) is fluidly connected to a suction device or is fluid-connectable to the negative pressure in the region of the receiving element ( 10 ) to create. Medical device according to claim 1, characterized by a guide wire ( 21 ) connected to the proximal end of the receiving element ( 10 ) and longitudinally displaceable within the microcatheter ( 20 ) can be arranged. Medical device according to claim 1 or 2, characterized in that the receiving element ( 10 ) has a net-like support structure. Medical device according to claim 3, characterized in that the net-like support structure comprises a wire mesh. Medical device according to claim 4, characterized in that the wire mesh has a braiding angle of at least 30 °, in particular at least 40 °, in particular at least 45 °, in particular at least 50 °, in particular at least 55 °, in particular at least 60 °, and / or at most 70 °, in particular at most 60 °, in particular at most 50 °, in particular at most 45 °, in particular at the most 40 °, in particular at the most 30 °, in particular at the most 20 °. Medical device according to at least one of claims 1 to 5, characterized in that the receiving element ( 10 ) at the proximal end at least one separating element ( 17 ) having a cutting area for cutting the concretion ( 40 ). Medical device according to at least one of claims 1 to 6, characterized in that the receiving element ( 10 ) in the expanded state, a radially expanded, in particular basket-like, suction ( 15 ) associated with the transport channel ( 12 ) connected is. Medical device according to at least one of claims 1 to 7, characterized in that the cover ( 13 ) of the transport channel ( 12 ) in use, in particular in the expanded state of the receiving element ( 10 ), fluid-tight with an inner surface of the guide catheter ( 30 ) can be brought into contact. Medical device according to at least one of claims 1 to 8, characterized in that the transport channel ( 12 ) has a length which is at least 4 times, in particular at least 6 times, in particular at least 8 times, in particular at least 10 times, in particular at least 15 times, in particular at least 20 times, in particular at least 25 times, in particular at least 30 times, an inner diameter of the guide catheter ( 30 ) corresponds. Medical device according to at least one of claims 1 to 9, characterized in that the guide catheter ( 30 ) has an inner diameter which is at least 0.8 mm, in particular at least 1.0 mm, in particular at least 1.2 mm, in particular at least 1.4 mm, in particular at least 1.5 mm, in particular at least 1.6 mm, in particular at least 1 , 8 mm, in particular at least 2.0 mm, in particular at least 2.2 mm, in particular at least 2.5 mm, in particular at least 3.0 mm, and / or at most 2.4 mm, in particular at most 2.2 mm, in particular at most 2.0 mm, in particular not more than 1.8 mm, in particular not more than 1.6 mm, in particular not more than 1.4 mm, in particular not more than 1.2 mm, in particular not more than 1.0 mm. Medical device according to at least one of claims 1 to 10, characterized in that a distal holding element ( 50 ) which is convertible from a compressed state to an expanded state and into the microcatheter ( 20 ) is retractable, wherein the retaining element ( 50 ) in the expanded state spaced from the inlet opening ( 11 ) of the receiving element ( 10 ) is arranged. Medical device according to claim 11, characterized in that the distal holding element ( 50 ) with the receiving element ( 10 ) and / or the guidewire ( 21 ) connected is. Medical device for removing concrements ( 40 ) from hollow organs of the body with a guide catheter ( 30 ), one in the guide catheters ( 30 ) longitudinally displaceable microcatheter ( 20 ) and one in the microcatheter ( 20 ) retractable receiving element ( 10 ), which is convertible from a compressed state to an expanded state and in the expanded state, a distally disposed, axial inlet opening ( 11 ), which is used for introducing a calculus ( 40 ) in the receiving element ( 10 ), the receiving element ( 10 ) a transport channel ( 12 ), which in the expanded state of the receiving element ( 10 ) hose-like between the inlet opening ( 11 ) and the microcatheter ( 20 ) and in the expanded state of the receiving element ( 10 ) has a cross-sectional diameter which is greater than a diameter of the microcatheter ( 20 ), the transport channel ( 12 ) at a proximal end at least one opening ( 14 ) such that the transport channel ( 12 ) with the guide catheter ( 30 ) is connectable, wherein distal of the receiving element ( 10 ) a holding element ( 50 ) is arranged, which is connected to an actuating element such that the holding element ( 50 ) relative to the receiving element ( 10 ) is movable to a concretion ( 40 ) in the axial inlet opening ( 11 ).

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