DE102010046408B4 - feed - Google Patents

Abstract

Delivery system comprising a catheter (10) and a medical functional element (11) with a compressible and expandable, rotationally symmetric lattice structure (12) which is arranged displaceably in the catheter (10) in the compressed state to the functional element (11) by a relative movement between the catheter (10) and functional element (11) from the catheter (10) to release and expand, wherein a return mechanism is provided to withdraw the discharged functional element (11) in the catheter (10), characterized in that the return mechanism is a flexible coupling element (14) with a plurality of spirally arranged wire threads (13), the distal end (13a) of each of which is fixedly connected to a proximal end (12a) of the lattice structure (12) and its proximal end (13b) for retracting the released functional element (11) in the catheter (10) releasably connected to an actuating element is such that the functional element (11) d a relative movement of the Drahtfädens (13) relative to the catheter (10) can be acted upon by a return force to retract the functional element after its complete expansion back into the catheter, wherein the fully released from the catheter (10) coupling element (12) is expandable such that the cross-sectional diameter of the expanded coupling element (14) is equal to or greater than the cross-sectional diameter of the expanded grid structure (12).

Description

The invention relates to a delivery system according to the preamble of claim 1. Such a delivery system is for example from the EP 1 374 801 A1 which discloses a delivery system with a catheter in which a guide wire is longitudinally displaceable. The guidewire includes at its distal end a plurality of coil-like elements supporting a stent. Concretely, the stent is arranged between two outer coil-like elements, wherein the outer coil-like elements almost completely fill the inner diameter of the catheter.

To then implant the stent, the delivery system, in particular the catheter tip, is guided to the treatment site. The treatment site may be, for example, a stenosis or an aneurysm. Subsequently, the catheter is moved relative to the guide wire so that the distal end of the stent is released. The distal end of the stent expands and attaches to the vessel wall. The expansion or expansion of the stent extends from distal to proximal with further proximal movement of the catheter.

US 2004/0122504 A1 discloses a vascular prosthesis having a plurality of ligaments helically wound around a longitudinal axis common to a stent structure, wherein the stent structure is formed of zigzag-shaped webs. Two webs each form a connector, each second connector being connected to a band. The intermediate connectors are free. The stent structure can be completely expanded in a vessel while the ligaments are still compressed in a catheter. However, when retracting the stent structure, there is a risk that the intermediate free connectors will become caught on the catheter tip, preventing it from being re-inserted into the catheter.

US 6,019,779 A deals with stents, which is formed as a coil of helically wound around a common longitudinal axis bands. The bands have the same winding direction. Such stents have insufficient stability in a blood vessel. In particular, they are not suitable for the treatment of aneurysms, which often occur in vessel bends. In such vessel curvatures, coil stents generally tend to expand to the outer radius of curvature, so that blood flow into an aneurysm located there is hardly inhibited. Also for stenosis treatment Coilstents are hardly suitable because their radial force is low.

In practice, it has proven to be expedient to partially release the stent initially during the implantation of the stent. Specifically, during implantation of the stent, the proximal end of the stent is held within the catheter as long as possible. This makes it possible to retract the stent into the delivery system or the catheter, if there is an undesirable change in position of the distal end of the stent. For example, the stent may be released from the catheter about as far as 70% to 80% of the stent is located outside the catheter relative to the stent length. In this way, on the one hand, the correct position of the stent can be controlled and, on the other hand, the influence of the blood flow or pulse beat on the position of the stent can be observed.

If a change in the stent position, so a repositioning is required, the catheter can be pushed in the distal direction over the stent, whereby the already expanded part of the stent is converted back into the compressed state. The implantation position can then be corrected and the stent released again.

The exact positioning of the stent with the known delivery system requires a high degree of sensitivity of the user, since even a small movement of the catheter in the distal direction can lead to complete discharge of the stent. A repositioning is then no longer possible. In other words, there is the risk in the known delivery system that the stent is used quickly and uncontrollably. This is all the more true, as the operation of the guide wire or the operation of the relative movement between the catheter and guidewire outside of the body, so relatively far away from the treatment site takes place. Since both the catheter material and the guide wire have elastic properties, movement at the proximal end of the catheter or guidewire has a different effect on the relative movement on the catheter tip, so that precise control of the release process is not possible.

Moreover, stents have the property of shortening in expansion. The stent length is thus dependent on the degree of expansion or on the expanded diameter of the stent. For the known delivery system, this means that with complete release of the stent, ie upon release of the proximal stent end from the catheter, a change in position of the stent may occur, which can not be reversed.

The invention is based on the object of specifying a delivery system for medical functional elements, which enables improved handling and offers increased positioning accuracy for the functional elements. In particular, with the invention, a delivery system is provided, with which it is possible, the Conditions in the implantation, in particular the positioning with respect to the treatment site, to be able to estimate the functional elements improved with the option to reposition the functional element.

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

The invention is based on the idea of specifying a delivery system for medical functional elements, which comprises a catheter and a medical functional element with a compressible and expandable, rotationally symmetrical lattice structure. The grid structure is arranged displaceably in the catheter in the compressed state in order to discharge and expand the functional element from the catheter by means of a relative movement between the catheter and the functional element. In this case, a return mechanism is provided to withdraw the discharged functional element in the catheter. The return mechanism has a flexible coupling element with a plurality of spirally arranged wire strands. The distal end of the respective wire thread is fixedly connected to a proximal end of the lattice structure. The proximal end of the respective wire thread is releasably connected to retract the discharged functional element in the catheter with an actuating element such that the functional element can be acted upon by a relative movement of the wire thread relative to the catheter with a return force to the functional element after its complete expansion back into the catheter withdraw. The coupling element completely released from the catheter is further expandable such that the cross-sectional diameter of the expanded coupling element is equal to or greater than the cross-sectional diameter of the expanded lattice structure.

In the context of the present application, the medical direction indications "distal" and "proximal" are based on the user of the medical device as a reference point. Distally arranged elements or areas are therefore further away from the user of the medical device than proximally arranged elements or areas.

The invention is thus based on the idea of providing a return mechanism between the completely discharged functional element and the catheter, which comprises a flexible coupling element. This ensures that with complete expansion of the functional element, for example in a blood vessel, a connection between the functional element and the catheter, so that the functional element is retractable into the catheter. The location and the behavior of the fully expanded functional element can thus be controlled and adjusted if necessary. Since the functional element is still connected to the catheter, a repositioning of the functional element is possible. In this case, the coupling element is preferably formed so flexible that the coupling element does not substantially affect the expansion of the functional element. The coupling element is detachably connected at its proximal end to an actuating element. The releasable connection allows release of the coupling element as soon as the final, correct position of the functional element is set. Upon complete release of the coupling element, the coupling element expands and assumes substantially the same cross-sectional dimension as the expanded functional element. The expanded coupling element can thus remain in the body together with the functional element. The coupling element is preferably adapted such that the coupling element in the implanted state, that is, upon complete release from the catheter, rests against the vessel wall of the body vessel. In the implanted state or fully discharged state, the coupling element essentially assumes the cross-sectional diameter of the body vessel. The fully expanded coupling element is aligned with the functional element.

The functional element exerts a radial force on the vessel wall, for example when used as a stent in a blood vessel. Likewise, the expanded, fully released coupling element causes a radial force on the vessel wall. The radial force of the coupling element is preferably smaller than the radial force of the functional element. The combination of the functional element with the coupling element thus additionally enables an improved introduction of force into the vessel wall. Specifically, the coupling element with the relatively lower radial force provides a smooth transition from the free vessel wall to the vessel wall portion supported by the functional element.

In general, the coupling element and the functional element can exert different radial forces on the vessel wall. On the one hand, the coupling element, as explained above, have a lower radial force than the functional element. On the other hand, the radial force of the coupling element may be equal to or greater than the radial force of the functional element. In the latter case, the coupling element can contribute to avoiding a so-called cigar shape of the functional element. The functional element per se can have the disadvantage of not being able to expand completely at the axial ends, so that the cross-sectional diameter of the axial ends of the functional element is smaller than the cross-sectional diameter of a middle section of the functional element. Thus, a cigar-like shape of the functional element can to adjust. By means of the coupling element, which has an equal or greater radial force than the functional element, it can be achieved that at least one axial end, in particular the proximal end, of the functional element widens completely so that the functional element as a whole forms a cylinder-like structure. Advantageously, it can be provided to arrange a coupling element at both axial ends of the functional element, wherein a distally arranged coupling element does not necessarily have to have a connection to an actuating element arranged within the catheter. The distally disposed coupling element is rather free. In particular, the distal coupling element can form an expansion element, wherein the structure of the expansion element corresponds to the structure of the proximal coupling element.

A coupling element with a higher radial force than the functional element has the advantage that the edge regions of the fully expanded functional element are pressed more strongly into the vessel wall. Thus, the fixation of the functional element can be improved at least at one axial end. The higher radial force of the coupling element is in a free state of the overall system, ie in an expanded state outside the body vessel, characterized in that the coupling element in the fully expanded state may have a larger cross-sectional diameter than the functional element. The difference between the cross-sectional dimensions of the coupling element and the functional element is substantially balanced in the implanted state by the body vessel, so that the coupling element in the implanted state is aligned with the functional element, wherein the coupling element exerts a greater radial force on the vessel wall. The different radial forces or expansion diameter of the coupling element and the functional element can be achieved, for example, by different braiding angles. Alternatively, the thickness of the wire elements may be different to set different radial forces. Suitable measures are known to the person skilled in the art.

Since the outer diameter of the expanded coupling element substantially corresponds to the outer diameter of the expanded lattice structure in the implanted state or the inner diameter of a body vessel to be treated, the function of the functional element is not impaired. In particular, blood flow through a body vessel is not affected by the coupling element.

In a preferred embodiment of the delivery system according to the invention, the wire thread has an impressed spiral shape in such a way that the wire thread spirals up after release from the catheter. In other words, the wire thread may have a helical spring-like shape, wherein the wire thread is in an elongated state within the catheter. During expansion, the wire thread resumes the original spiral shape and thus stretches spirally in a body vessel. The spiral shape allows a simple automatic and space-saving arrangement of the wire thread and the coupling element in the expanded state. In particular, the spiral shape allows a particularly simple approach of the shape of the expanded coupling element to the shape of the expanded functional element.

The distal end of the wire thread may be attached to a tip of a proximal marginal cell of the grid structure. Preferably, the lattice structure comprises cells, wherein the cells forming the proximal end of the lattice structure are referred to as marginal cells. The edge cells may, for example, have a diamond-like shape. The proximal end of the lattice structure is bounded by apices of the proximal marginal cells. The tips of the proximal marginal cells preferably point in the proximal direction. The connection of the wire thread with a tip of a proximal edge cell is particularly easy to produce and allows easy compression of the fully released functional element.

The coupling element has a plurality of wire threads which are each attached to a tip of a proximal edge cell of the grid structure such that the coupling element is connected to all the tips of the proximal edge cells. The stability of the connection between the coupling element and the functional element is increased in this way. Furthermore, the repositionability of the functional element is improved, since the functional element is comparatively easily compressible by the connection of the coupling element with all the tips of the edge cells of the lattice structure in order to be withdrawn into the catheter. In particular, it is avoided by the connection of the coupling element with all the tips or all free ends of the functional element that when retracting the functional element in the catheter open ends of the functional element consist, which can get caught and thus block a retraction of the functional element. Thus, by the connection of all the tips with the coupling element damage to the functional element or a violation of the vessel wall is avoided. For a complete repositionability or a complete retraction or removal of the functional element after a complete expansion within a body vessel, therefore, the connection of the coupling element with all the tips or free ends of the functional element is particularly advantageous.

• 1: eine Seitenansicht eines erfindungsgemäßen Zuführsystems gemäß einem bevorzugten Ausführungsbeispiel, wobei ein vollständig expandiertes Funktionselement mit einem Katheter des Zuführsystems durch ein flexibles Kopplungselement verbunden ist;
• 2: eine Seitenansicht des Zuführsystems gemäß 1, wobei das Kopplungselement vollständig entlassen ist;
• 3a-3c: jeweils eine schematische Seitenansicht eines erfindungsgemäßen Zuführsystems in unterschiedlichen Stadien der Entlassung des Funktionselements.

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

• 1 a side view of a delivery system according to the invention according to a preferred embodiment, wherein a fully expanded functional element is connected to a catheter of the delivery system by a flexible coupling element;
• 2 a side view of the delivery system according to 1 wherein the coupling element is completely discharged;
• 3a-3c in each case a schematic side view of a delivery system according to the invention in different stages of the discharge of the functional element.

In 1 is a delivery system for medical functional elements 11 shown that a catheter 10 and a medical functional element 11 includes. The medical functional element 11 may be a medical implant or a prosthesis. In particular, the functional element 11 a stent, a blood filter, a thrombosis scavenger or thrombectomy device, a vascular prosthesis or other medical implant that is a compressible and expandable, rotationally symmetric lattice structure 12 includes. In the in the 1 and 2 illustrated embodiments is the functional element 11 designed as a stent.

The stent or generally the functional element 11 is compressible and expandable. Specifically, the functional element 11 from a compressed state to an expanded state and vice versa. Preferably, the functional element 11 formed rotationally symmetrical and comprises a grid structure 12 ,

The grid structure 12 can be made by a material-removing process of a solid material. In particular, the lattice structure 12 be made by laser cutting from a flat or tubular body. When using a flat body, it is preferred if the cut lattice structure 12 then transferred into a tube shape. The grid structure 12 may also be made by a sputter etching process. On the one hand, the lattice structure can be achieved by the sputter etching method 12 be formed in their rotationally symmetrical shape. On the other hand, a flat lattice structure can first be produced by the sputter etching process, which is then converted into the tube shape.

The sputter etching method may include etching steps applied to a substrate. In a subsequent method step, the material of the lattice structure 12 be applied by sputtering or in general a physical deposition on the etched substrate, so that the lattice structure 12 is formed directly or the webs of the lattice structure 12 be formed directly. Alternatively, first a material layer can be sputtered, which is then treated by etching, so that the lattice structure 12 forms, wherein the etching of the openings of the lattice structure 12 be exposed. The sputter etching method has the advantage that special microstructural properties of the lattice structure are set, which are advantageous for the functioning of the functional element 11 or coupling element 14 can affect.

For lattice structures 12 When fabricated by laser cutting or a sputter etching process, it is advantageous to have at the axial ends of the lattice structure 11 or of the functional element 11 Provide structures that serve as X-ray markers. Such X-ray marker structures or elements may have larger dimensions than the components of the remaining grid structure 12 , Preferably, x-ray marker elements are at tips 16 the axial ends of the lattice structure 12 arranged. The x-ray markers at the tips 16 are advantageous with the coupling element 14 , especially wire threads 13 of the coupling element 14 , connected. The coupling element 14 can help to place the X-ray marker elements in the implanted state on a vessel wall. For this purpose, the coupling element 14 For example, a greater radial force than the functional element 11 exhibit.

Alternatively, the grid structure 12 include a wire mesh. In this case, a plurality of spirally wound around a common axis of rotation wires may be provided, wherein the wires are partially guided in different directions of rotation about the axis of rotation. The wires cross each other at crossing points. The wires can cross over and cross each other alternately in adjacent crossing points, so that a meshwork results. Different braiding variants are conceivable. For example, a first wire element may cross over an opposite, second wire element at each second crossing point and intersect at the intermediate point of intersection. Such a braid is called 1-over-1 braiding. Alternatively, a first wire element may intersect an opposing second wire element at every third intersection, the wire element intersecting the opposing wire element in the two intermediate points of intersection. Such a braid is called 2-over-1 braiding. In further variants, for example, a 2-over-2 weave, a 1-over-2 weave, a 1-over-3 weave, 2-over-3 plaiting, 3-over-3 plaiting, or similarly varied plaits may be provided.

It is also possible, the wire mesh of the grid structure 12 of the functional element 11 be designed such that at least two, in particular several, in particular all, wires of the grid structure 12 at the proximal end of the functional element 11 can be summarized to one or more wire ends. In this case, the summarization of the wire ends by means of twisting, braiding, crimping, gluing, welding, soldering or other connection techniques. Preferably, all the wires of the grid structure 12 are combined into a single end or form a single combined wire end, which with the coupling element 14 connected is. In the expanded state of the functional element 11 can thus have a sloping proximal end 12a or summarized wire end be formed. Such a shape of the proximal end 12a the lattice structure 12 is for example in DE 10 2009 056 450 A1 described by the Applicant. When using such a lattice structure 12 for the functional element 11 For example, a coupling element 14 be provided, the several wire threads 13 having.

The grid structure 12 or generally the functional element 11 is in the catheter 10 slidably arranged, the lattice structure 12 is present within the catheter in the compressed state. The inner diameter of the catheter causes this 10 that the functional element 11 or the grid structure 12 remains in the compressed state. In general, the lattice structure 12 or the functional element 11 be self-expandable. For example, the grid structure 12 comprise a shape memory material that causes the lattice structure to release from the catheter after release 10 is automatically expanded or expanded. Preferred materials are, for example, nickel-titanium alloys or shape memory polymers.

Due to the displaceable arrangement of the lattice structure 12 in the catheter 10 will allow the functional element 11 by a relative movement between the catheter 10 and the functional element 11 out of the catheter 10 is dismissed. The release of the functional element 11 So there is a relative movement between the functional element 11 and the catheter 10 , Specifically, the functional element 11 coupled to an actuator (not shown) operable by a user. The actuator may be opposite to the catheter 10 be moved relatively, so that the relative movement between the functional element 11 and the catheter 10 established. For example, the actuating element may comprise a guide wire which, at the proximal end, that is to say outside the body to be treated, is separated from the catheter by a user 10 is movable. Thus, the relative movement between the functional element 11 and the catheter 10 be controlled by the user outside.

The delivery system further comprises a return mechanism that causes the at least partially released, in particular completely dismissed, functional element 11 retractable into the catheter. The return mechanism comprises a flexible coupling element 14 which is arranged between the functional element 11 and the actuating element. Specifically, the coupling element connects 14 the functional element 11 with the actuating element. The coupling element 14 is with the functional element 11 firmly connected. Between the coupling element 14 and the actuator is a releasable connection. The detachable connection between the coupling element 14 and the actuator can be effected for example by an undercut. In general, therefore, the coupling element 14 be positively connected to the actuator, wherein the positive connection with complete release of the coupling element 14 can solve automatically from the catheter. Alternatively, the connection between the coupling element 14 and be actively detachable to the actuating element, for example by a rotational movement of the actuating element. Other releasable connection mechanisms are possible. The coupling element 14 may also be frictionally connected to the actuator. The frictional connection can be released automatically after discharge from the catheter.

Specifically, the coupling element has 14 at least one spirally arranged wire thread 13 on. It is also possible that the coupling element several wire strands 13 includes, for example, five wire threads 13 , as in 1 shown. For more than one wire thread 13 it can be provided that the wire threads each form opposite spirals. Preferably, the wire threads 13 spirally wound in the same direction of rotation ( 1 ).

The several spirally arranged wire threads 13 each have a distal end 13a on, with a proximal end 12a the lattice structure 12 is firmly connected. In particular, the distal end 13a of the wire thread 13 with the proximal end 12a the lattice structure 12 welded, glued or formed in one piece.

The wire thread 13 also has a proximal end 13b on, which is detachably connected to the actuating element. The length of the wire thread 13 is preferably adapted such that the length of the coupling element 14 So the distance between the proximal end 12a the lattice structure 12 to the catheter 10 at least the simple, in particular at least twice, expanded cross-sectional diameter of the functional element 11 equivalent. The length of the coupling element 14 can also at least three times, in particular at least four times, expanded cross-sectional diameter of the functional element 11 correspond.

It is advantageously provided that the connection between the coupling element 14 and the grid structure 12 through the connection of the distal end 13a of the wire thread 13 with a tip 16 a border cell 15a the lattice structure 12 he follows. In other words, the lattice structure 12 cell 15 on, through the bridges 17 the lattice structure 12 are limited. At the axial ends of the lattice structure 12 or in the edge regions of the lattice structure 12 form the cells 15 boundary cells 15a , The marginal cells 15a are diamond-shaped and have three corners, each with a further cell 15 through a crossing point 18 of the bridges 17 are connected. A fourth corner of the peripheral cell 15a forms a free tip 16 , The tips 16 all border cells 15a limit the lattice structure 12 in the axial direction or define the proximal end 12a the lattice structure 12 , The wire thread 13 or specifically the distal end 13a of the wire thread 13 is preferably with the tip 16 the border cell 15a firmly connected. It is particularly preferred if the coupling element 14 several wire threads 13 includes, each with a tip 16 are connected. Preferably, all peaks 16 with a wire thread 13 firmly connected.

The coupling element 14 has essentially analogous to the functional element 11 Self-expanding properties. The self-expanding properties of the coupling element 14 may be caused on the one hand by a spring-like force component resulting from the spiral shape of the wire threads 13 results. Alternatively or additionally, the self-expandable properties can be achieved by the material of the wire threads 13 be effective. For example, the wire threads 13 a shape memory metal or a shape memory polymer. In particular, the wire thread 13 have a nickel-titanium alloy.

The wire thread 13 can with the functional element 11 be connected by crimping, gluing, welding, knots or a positive connection. This applies to both wire threads 13 , which include a shape memory metal, as well as for wire threads 13 which are made of a polymer. wire filaments 13 , which include a metal, can also by riveting or soldering with the functional element 11 be connected. For wire threads 13 From a polymer, it has proven to be advantageous to use biodegradable polymer materials.

In this way, the functional element 11 be securely positioned, with the wire threads 13 of the coupling element 14 dissolve after some time in the body vessel. Thus, only the functional element remains in the body vessel in the long term 11 ,

In general, the wire threads 13 be made of a drawn metal wire or polymer wire. It is also conceivable that the wire threads 13 produced by a sputtering etching process. The wire threads 13 can with the grid structure 12 of the functional element 11 directly connected, in particular formed in one piece, be. This can be the wire threads 13 together with the grid structure 12 be prepared by a sputter etching process. If the grid structure 12 comprises a wire mesh, the coupling element 14 be formed by continuation of the wire mesh, wherein the coupling element 14 preferably has a different braid angle, as the functional element 11 , Furthermore, it can be provided that the wire threads 13 each comprise an x-ray marker element at its proximal end. Alternatively, the wire strands 13 may be made entirely of a radiopaque material. Furthermore, it can be provided, the wire threads 13 form multi-layer, wherein at least one layer comprises a radiopaque material. For example, the wire threads 13 comprise a core wire, in particular comprising a nickel-titanium alloy. The core wire may be spirally wrapped by a sheath wire, the sheath wire comprising an X-ray visible material.

The wire threads 13 of the coupling element 14 are preferably arranged spirally. The spiral shape can be adapted such that the coupling element 14 during expansion has a greater change in length than the functional element 11 , The effect of the change in length during expansion is called foreshortening. The enlargement of the cross-sectional diameter of the wire threads causes 13 or the grid structure 12 simultaneously a shortening of the coupling element 14 or functional element 11. The coupling element 14 It shortens preferably stronger than the functional element 11 , Due to the relatively high foreshortening of the coupling element 14 becomes a relative movement between the actuating element and the functional element 11 damped or delayed. Thus, a comparatively gentle repositioning of the functional element 11 possible. In particular, in the repositioning the coupling element 14 initially retracted by the actuator into the catheter. In this first repositioning step, the catheter and the functional element become 11 kept stationary. In the second repositioning step, after the coupling element 14 is almost completely arranged in the catheter, the functional element 11 kept stationary and the catheter in the distal direction on the functional element 11 pushed. In this way, this is done by retracting the coupling element 14 already precompressed functional element 11 further compressed and placed in the catheter. Because throughout the Repositionierungsvorgangs the functional element 11 is held substantially stationary, a vascular injury is avoided.

In the following, the operation of the delivery system based on the 3a-3c explains:

For implantation of a stent or general functional element 11 in a body vessel, for example a blood vessel 20 , the delivery system is first led to the treatment site ( 3a ). This can be done by the catheter 10 in which the stent or the functional element 11 is arranged in the compressed state, via a guide wire 19 be guided. The guidewire 19 can the actuator for the functional element 11 form. Here is the guidewire 19 detachable with the coupling element 14 connected.

The release of the stent or functional element 11 takes place by a relative movement between the catheter 10 and the guidewire 19 or generally by a relative movement between the catheter 10 and the functional element 11 , Preferably, the guide wire 19 or the functional element 11 held stationary and the catheter 10 simultaneously moved in the proximal direction. At the same time the catheter slides 10 via the functional element 11 wherein a distal portion of the functional element 11 is exposed. The distal portion of the functional element 11 expands in the blood vessel 20 on or expands ( 3b ). Here is the stent or functional element 11 partially expanded. This means that a proximal portion of the stent or functional element 11 still in the compressed state inside the catheter 10 is arranged. By further movement of the catheter 10 in the proximal direction becomes the functional element 11 completely in the blood vessel 20 released. At the same time, the proximal movement of the catheter 10 the coupling element 14 at least partially released. The coupling element 14 spans essentially funnel-shaped and thus forms a connection between the functional element 11 and the catheter 10 , The functional element 11 can now be observed in the fully expanded state, for example by an imaging method based on X-rays. In particular, it can be observed whether, on the one hand, the position of the functional element 11 is correct and on the other hand the blood flow in the blood vessel 20 or mechanical activities of the vessel wall, caused for example by the pulse beat, effects on the position or function of the functional element 11 to have. Through the connection between the catheter 10 and the functional element 11 over the coupling element 14 is guaranteed that the functional element 11 For example, for repositioning, in the catheter 10 is retractable. This is the catheter 10 in the distal direction, ie on the functional element 11 too, moved. The wire threads 13 of the coupling element 14 be in this way in the catheter 10 pushed back, wherein the coupling element 14 is compressed. This means that the winding diameter of the spirally wound wire threads 13 is gradually reduced. By the firm connection of the wire threads 13 with the grid structure 12 of the functional element 11 is further causes the functional element 11 from the expanded state to the compressed state. The functional element 11 is thus by a distal movement of the catheter 10 over the coupling element 14 Compressible and can enter the catheter 10 be recorded. Once the functional element 11 inside the catheter 10 is arranged, the implantation position of the functional element 11 Getting corrected.

To the functional element 11 completely in the blood vessel 20 to discharge, becomes the catheter 10 further in the proximal direction moves to the coupling element 14 or the wire threads 13 of the coupling element 14 completely the catheter 10 have left. The wire threads 13 then expand automatically and lie down to the proximal end 12a the lattice structure 12 at. Thereby take the wire threads 13 or generally the coupling element 14 substantially the same outer diameter as the expanded functional element 11 in the implanted state. The outer diameter substantially corresponds to the inner diameter of the treated body vessel, wherein the coupling element 14 and the functional element 11 can apply different radial forces on the vessel wall.

The completely dismissed functional element 11 with completely released coupling element 14 is in 2 shown.

The detachable connection between the coupling element 14 and the actuator or guidewire 19 may be formed, for example, by hook-like or pin-like elements on the guide wire 19 or are arranged on the actuating element. The hook-like or pin-like elements preferably extend in the radial direction and form, for example, a star-shaped holding means for the wire threads 13 , The star-shaped holding means has a cross-sectional diameter which is substantially equal to the inner diameter of the catheter 10 equivalent. The wire threads 13 may be at the proximal ends 13b each have a loop into which engages the hook-like or pin-like retaining element. The hook-like or pin-like elements fix the wire threads 13 in the axial direction. In the radial direction are the wire threads 13 through the inner diameter of the catheter 10 fixed. Once the hook-like or pin-like elements or generally the star-shaped holding element outside of the catheter 10 is arranged, is the radial boundary for the loops of the wire threads 13 solved, so that the wire threads 13 can span in the radial direction automatically.

LIST OF REFERENCE NUMBERS

10

catheter

11

functional element

12

lattice structure

12a

proximal end of the lattice structure 12

13

wire filament

13a

distal end of the wire thread 13

13b

proximal end of the wire thread 13

14

coupling element

15

cell

15a

edge cell

16

top

17

web

18

intersection

19

guidewire

20

blood vessel

Claims (4)

Delivery system comprising a catheter (10) and a medical functional element (11) with a compressible and expandable, rotationally symmetric lattice structure (12) which is arranged displaceably in the catheter (10) in the compressed state to the functional element (11) by a relative movement between the catheter (10) and functional element (11) from the catheter (10) to release and expand, wherein a return mechanism is provided to withdraw the discharged functional element (11) in the catheter (10), characterized in that the return mechanism is a flexible coupling element (14) with a plurality of spirally arranged wire threads (13), the distal end (13a) of each of which is fixedly connected to a proximal end (12a) of the lattice structure (12) and its proximal end (13b) for retracting the released functional element (11) in the catheter (10) releasably connected to an actuating element is such that the functional element (11) by a relative movement of Drahtfädens (13) relative to the catheter (10) can be acted upon by a return force to retract the functional element after its complete expansion back into the catheter, wherein the fully released from the catheter (10) coupling element (12) is expandable such that the cross-sectional diameter of the expanded coupling element (14) is equal to or greater than the cross-sectional diameter of the expanded grid structure (12). Feeding system after Claim 1 , characterized in that the wire threads (13) each have an impressed spiral shape such that the wire threads (13) roll up after discharge from the catheter (10) spirally. Feeding system after Claim 1 or 2 , characterized in that the distal end (13a) of each wire thread (13) is attached to a tip (16) of a proximal marginal cell (15a) of the grid structure (12). Feeding system according to one of Claims 1 to 3 , characterized in that the wire threads (13) are each fastened to a tip (16) of a proximal edge cell (15a) of the lattice structure (12) such that the coupling element (14) is connected to all the tips (16) of the proximal edge cells (15a). connected is.

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