EP4065033A1

EP4065033A1 - Marking element for marking tissue

Info

Publication number: EP4065033A1
Application number: EP20817255.1A
Authority: EP
Inventors: Dirk Hornscheidt
Original assignee: Somatex Medical Technologies GmbH
Current assignee: Somatex Medical Technologies GmbH
Priority date: 2019-11-29
Filing date: 2020-11-30
Publication date: 2022-10-05
Also published as: CN114746046A; JP2023505106A; AU2020392703A1; WO2021105506A1; CN115066217A; CA3160617A1; WO2021105511A1; CA3162950A1; EP4065034A1; DE102019132558A1; AU2020392700A1; JP2023505114A; US20230000586A1; US20230000585A1

Abstract

The invention relates to a marking element for marking body tissue. The marking element has a shape which is at least approximately rotationally symmetrical about a longitudinal axis, and the marking element consists of interconnected preshaped elastic metal braces and can assume a radially compressed state and a radially expanded state. In the expanded state, the marking element is constricted in a central longitudinal section and expands continuously from the central longitudinal section towards the two sides in the longitudinal direction. The marking element has two widened longitudinal sections, the maximum outer diameter of which is two times to twenty times larger than the outer diameter of the central longitudinal section in the expanded state of the marking element. The marking element is made of 10 to 40 braces in the circumferential direction at least in the widened longitudinal sections, said braces running substantially in the longitudinal direction of the marking element when the marking element is in the compressed state and being connected together at intersection points.

Description

Marking body for marking tissue

The invention relates to a marker body with an elastic, compressible and self-expanding support structure intended for implantation in a soft tissue (e.g. fat tissue, muscle tissue, tumor tissue, breast tissue, liver tissue, lymph nodes, in particular the axillary lymph nodes or the like). The support structure is formed by elastic and preformed struts. The marking body has a shape that is at least approximately rotationally symmetrical about a longitudinal axis. The invention also relates to an implantation system and a method for implantation.

Implantable marking bodies for marking tissue sites are generally known. Such marking bodies are generally designed so that they can be implanted into the tissue region to be marked using a suitable device in order to remain there permanently or for a certain period of time, for example between two interventions. In this way, tissue relevant for the treatment, which has tumors or other tissue abnormalities, for example, or potentially healthy tissue that is to be observed, can be identified for a longer period of time. The marking effect of these marking bodies is achieved by their visibility during the examination using diagnostic imaging methods, in particular in the case of methods based on X-rays, nuclear magnetic resonance or ultrasound waves. WO 2006/000568 A2 discloses a marker for marking a tissue site after this marker has been inserted with an applicator or a cannula of known design. What is achieved here is that the marker remains in the tissue site to be marked for a longer period of time and thus clearly marks a tissue site for a later diagnostic and therapeutic activity. The marker consists of one or more wires which are twisted in the central marker section and which can have different shapes at the two end sections of the marker.

A surgical instrument, in particular a marker instrument for marking body tissue sections, is also described in EP 1 782 745 B1. The instrument should in particular be suitable for marking tumor tissue before this tissue is surgically removed.

A production method for the production of spherical cage structures consisting of nitinol from the field of surgical orthopedics for the treatment of bone necrosis is disclosed in US Pat. No. 8,112,869 B2. The cage structures produced according to the method described there are intended to stabilize the femoral head by being introduced in compressed form through a channel drilled through the femur, expanding in the femoral head and then filling cavities with compressed bone graft. The diameter of the cage structures in this area of application is between 20 and 30 mm. US Pat. No. 9,216,069 B2 describes a marker system for the biopsy of the breast in which a multiplicity of marker elements, which contain at least one radiopaque wire segment, are pre-loaded in compressed form in an administration tube.

US Pat. No. 8,060,183 B2 generally discloses a marker enclosing a cavity for marking biopsies of the breast in imaging methods. In a variant, the marker consists of an outer hollow body closed at both elongated ends and a smaller permanent marker located inside the outer body. It is also described that the outer hollow body consists of a bioresorbable material and degrades over a certain period of time, while the inner permanent marker expander remains in the tissue. The object of the invention is to provide an improved marker body for implantation in a tissue. To achieve the object, a marker body according to claim 1 is proposed. Accordingly, the marking body has a shape that is at least approximately rotationally symmetrical about a longitudinal axis and can assume a radially compressed and a radially expanded state. The marking body is formed by elastic and preformed struts which result in an elastic, compressible and self-expanding support structure. The struts are connected to one another, for example by weaving or in some other way. In its expanded state, the marking body is constricted in a central longitudinal section and, starting from the central longitudinal section, widens in the longitudinal direction towards both longitudinal ends, so that it has two widened longitudinal sections, each of which can be approximately conical, for example, with the cone tips touching . The maximum outer diameter of the expanded longitudinal sections is two to twenty times larger than the outer diameter of the central longitudinal section in the expanded state of the marking body. The marker body is formed at least in the widened longitudinal sections in the circumferential direction from 5 to 96 struts, which in the compressed state of the marker body run essentially in its longitudinal direction and which cross in pairs at their longitudinal ends and are connected to one another there materially and / or positively. Running essentially in the longitudinal direction of the marking body means that the struts in the compressed state of the marking body run at an angle of less than 10 ° to the longitudinal axis of the marking body.

Such a marking body can advantageously meet two requirements: on the one hand, it offers good ultrasound visibility and, on the other hand, it counteracts migration, that is, migration of the marking body in the tissue during and after the implantation.

If a biopsy, for example a vacuum biopsy, has been carried out before the marking, the tissue pressure acting against the direction of propagation of the marking body can be correspondingly lower or not present due to an already existing cavity. In such a case, the expansion of the marker body after it has been set prevents the marker body from falling back into the biopsy cannula or from being flushed out through the puncture channel of the vacuum biopsy unit.

As a further aspect of the invention, an implantation system with a marker body and an implantation device is proposed. The invention is based on the consideration that the visibility of marking bodies should also be ensured in imaging methods based on different operating principles. Furthermore, the unambiguous and distinct visibility of marking bodies should be guaranteed under the widest possible range of examination conditions and applications. In the case of imaging methods based on ultrasound, the marking body can be easily identified through the highest possible sound reflection from the support structure formed by metal or hard plastic.

In the case of sonography with medical ultrasound at 1 MHz to 40 MHz in B-mode (brightness modulation), the support structure of the marking body has the effect that incident ultrasound waves across both longitudinal ends of the marking body hit a structure with a circular cross-section. By coordinating the parameters - strut diameter (or width and thickness), number of struts, strut density and strut material, it is achieved that only part of the sound energy is reflected by the structure and the remaining part of the energy is let through becomes. This creates a full circle as a representation in the ultrasound image. With other structures of this form, the ultrasonic energy is largely reflected on the first surface of the marker and a shadow is created in the image.

A further feature of the selected marker body geometry consists in that incident ultrasonic waves at both longitudinal ends of the marker body can be seen on a cross in the ultrasound image instead of a circle. Both geometries, the circle and the cross, do not appear in the form in the ultrasound image of the biological tissue and are therefore particularly easy for the examiner to recognize and to assign to the marking body.

Even with imaging processes based on X-rays, such as mammography, a high level of absorption of the X-rays by the supporting structure leads to good visibility in the X-ray image. The high absorption of X-rays by the supporting structure is due to the metal of the supporting structure, e.g. the metal wires or metal particles embedded in plastic.

In magnetic resonance tomography (MRT), the magnetic properties of the material of the marking body make it easy to recognize. Advantageous further developments of the invention can be found in the subclaims and indicate in detail advantageous possibilities for realizing the concept explained above within the scope of the task and with regard to further advantages.

In particular, it is provided that the support structure is woven, braided, wound or knitted. The advantage here is the economic producibility of a structure that spreads over an area, which in a subsequent production step is brought into a hollow, double-conical shape in which the cone tips meet in the middle.

Alternatively, the support structure can be formed by a small tube which is slit in the longitudinal direction and which is compressed so that the sections separated from one another by the slots curve outward. If the compressed state of such a support structure is its relaxed state, the support structure is self-expanding.

Another alternative for the support structure is a support structure made of plastic, e.g. a marker body made by injection molding, e.g. made of PEEK. The support structure of the marking body is preferably designed so that it is self-expanding and can be elastically compressed under a radial force of at least one Newton. If the marker body is implanted in tissue in the elastically compressed state, the marker body changes automatically into its expanded state and maintains this when the tissue exerts a radial force of less than one Newton on the marker body.

For implantation, the marker body is first brought to the desired location by means of a cannula and then pushed out of the lumen of the cannula so that it can then expand in the tissue. The expansion force with which the marking body held in compressed form in the cannula expands immediately after being ejected from the cannula is preferably at least 1 Newton.

The support structure of the marking body can be designed, for example, in such a way that it has an expansion force which, when the marking body is compressed to a maximum diameter of less than 1 mm, is more than 40 Newtons and, with a maximum diameter of 1.5 mm, is still more than three Newtons, for example - se is six Newtons. The support structure of the marking body can be designed in such a way that its expansion force essentially corresponds to that radial force which has to be expended minimally in order to compress the marking body elastically.

The energy stored in the support structure of the marking body can be adjusted by a suitable choice of the strut thickness of the struts of the support structure or the number of struts of the support structure. The energy stored in the support structure of the elastically compressed marking body also depends on the material from which the struts of the support structure of the marking body are formed. Accordingly, it is also possible to manufacture the marking body according to the invention in such a way that a radial force of more than 1.5 Newtons, two Newtons or even more than three Newtons has to be applied in order to compress the marking body to a maximum diameter of less than 1.5 mm. It is also possible to manufacture the marking body according to the invention in such a way that a radial force of 0.5 Newtons is sufficient to compress the marking body to a maximum diameter of less than 1.5 mm. Since the supporting structure of the marking body is designed to be self-expanding, the marking body changes automatically into its expanded state as soon as the radial force required for elastic compression of the marking body is not reached. The supporting structure of the marking body is preferably formed from individual wires that are intertwined with one another. Accordingly, the struts of the marking body are preferably formed from 5 to 96 wires, for example from 18 to 48 wires and in particular from 24 or 36 wires, each extending from one to the other longitudinal end of the marking body and crossing each other several times and in this way one Form grid-like support structure from a wire mesh with a plurality of intersection points. Particularly preferred is a marking body which is formed from 12 to 48, in particular 24, interwoven wires, which preferably consist of a titanium alloy, in particular nitinol.

The struts of the marking body, for example the wires, are preferably connected to one another in pairs at their free longitudinal ends and are particularly preferably welded, in particular twisted and welded. For this purpose, the free longitudinal ends are preferably each located at a point of intersection of the support structure, that is to say, for example, where the wires cross in the wire mesh. The struts of the marking body can also be materially connected to one another at the crossing points, in particular welded. However, this is preferably not provided.

As an alternative or in addition, the struts of the marking body can be twisted with one another at the points of intersection.

Preferably, the outer diameter of the marking body increases steadily in its expanded state starting from the central longitudinal section in the longitudinal direction towards both longitudinal ends, so that the marking body has its maximum diameter at its two longitudinal ends. In an alternative embodiment variant, the outer diameter of the marking body in its expanded state initially increases starting from the central longitudinal section in the longitudinal direction towards both longitudinal ends and then decreases again in the further course towards the longitudinal ends, so that the marking body is at a distance from its respective longitudinal ends has its maximum diameter.

In both cases, the marker body ideally has the same maximum diameter in the widened longitudinal sections. In practice, however, the two maximum diameters typically differ somewhat from one another, but the difference between the maximum diameters in the radially unloaded state of the marking body is preferably less than 10%.

In the expanded state, the marking body preferably expands in the widened longitudinal sections starting from the central longitudinal section at an opening angle which - based on a longitudinal axis of the marking body - is between 25 ° and 50 °, and in particular between 30 ° and 45 °. In the case of a marking body formed from interwoven wires, the wire diameter is preferably less than 0.5 mm, preferably less than or equal to 0.1 mm, for example between 0.05 mm and 0.10 mm. A small wire diameter has a positive effect on the compressibility of the marking body, which is required when implanting via a cannula with the smallest possible diameter. A larger wire diameter, on the other hand, has a positive influence on the erecting force of the supporting structure of the marking body. This leads to the fact that the marker body can also expand against a tissue pressure prevailing in hard tissue, for example tumor tissue.

It is also advantageous if the diameter of the marker body in the expanded state is less than 10 mm or less than 8 mm, preferably between 3.0 mm and 5.0 mm. A marker body in this diameter range represents a compromise between visibility in imaging processes on the one hand and the bulk of a foreign body in the tissue on the other.

An expanded marker body with a certain minimum size offers the advantage that it can be felt by a surgeon during the treatment. It is also preferred if the diameter of the marking body in the compressed state is less than 3 mm, preferably less than 1.0 mm. A small diameter in the elastically compressed state or a high compressibility of the marking body enables the marking body to be implanted with a relatively thin cannula, that is to say with a small diameter. With a small diameter, the risk of injury and pain to the patient is reduced, and a stab incision and / or anesthesia can be dispensed with more frequently in the context of simplified handling. This also results in advantages in terms of duration and costs of use.

The support structure, for example its wires and / or sleeve, is preferably roughened, for example by sandblasting, in order to increase the ultrasound visibility.

The struts of the marking body are preferably made of a titanium alloy, in particular of nitinol. Due to the material properties of nitinol as a super-elastic material, this has the advantage that the marker body changes automatically from an elastically compressed to an expanded state after it has been removed from the implantation device, in particular against the pressure of the tissue adjacent to the marker body acting against the direction of expansion . The use of other super-elastic materials and / or shape memory alloys is also possible.

A rapid self-expansion of the marker body after its implantation is guaranteed, for example, by the use of nitinol To prevent migration of the marker body, especially during and after the implantation.

Furthermore, it is advantageously provided that the material of the support structure is not resorbable. This aspect of the invention leads to the advantage that the marker body, which as a rule remains in the tissue for a longer period of time, does not degrade. This also prevents the marker body from interacting in an unfavorable manner with the adjacent tissue, in particular through the release of ingredients or material components of the support structure to the adjacent tissue.

The wires of a support structure formed by a multiplicity of wires do not all have to consist of the same material. Rather, individual wires made of other materials can also be braided in to optimize visibility in magnetic resonance tomography or to increase X-ray visibility in computer tomography or under C-arms. Suitable materials are e.g. titanium, gold, ferrous alloys and / or nitinol. In particular, if the supporting structure of the marking body is formed by a wire mesh, the central longitudinal section can be provided with a sleeve which compresses the central longitudinal section to a minimum diameter, preferably in such a way that all the struts in the central longitudinal section lie directly against one another laterally. The sleeve has the further effect that it holds all the individual wires together in a clamping manner, for example, so that a connection of the individual wires at their longitudinal ends is obsolete, but can be provided for reasons of redundancy.

Preferably the sleeve is a nitinol sleeve. Instead of a nitinol sleeve, other clamps, e.g. sleeves made of a different material, can also be used. Such clamps can also have different shapes. The clamps can therefore differ from one another in terms of shape and length, for example. This makes it possible to use marker bodies with different clamps so that individual marker bodies can also be identified individually after implantation.

Further differentiating features of individual marking bodies can be clamps made of different materials, for example clamps with more or less radio-opaque properties or clamps with different magnetic properties, in particular for differentiation in images recorded by magnetic resonance tomography. Clamps with Air / gas inclusions can result in improved recognizability in the ultrasound image.

Furthermore, it is advantageously provided that the marking body also contains marking features in addition to or in addition to the supporting structure, e.g. sleeves of different shapes and / or lengths, in particular metallic or other X-ray-opaque molded parts within the supporting structure. This has the advantage, among other things, that several different marker bodies which are implanted in a patient at the same time can be clearly, or at least more simply, differentiated in imaging methods. These molded parts can be, for example, rods or balls located within the supporting structure or fastened to the supporting structure, which can furthermore have different dimensions for better differentiation. These molded parts can be formed from metal, for example.

Another aspect is an implantation system with a marking body of the type claimed here and an implantation device. The implantation device is designed for implanting the marking body according to the invention and has a cannula for this purpose. The marking body can thus advantageously be placed via the implantation device by puncturing the skin layers and the underlying tissue at the tissue site to be marked, in particular using imaging methods. It is advantageously provided that the outer diameter of the cannula of the implantation device is less than 3 mm, preferably between 1.6 mm and 1.2 mm. This leads to the advantage that the marking body can be implanted in a percutaneous manner, in particular due to the small cannula diameter. In particular, the small outer diameter of the cannula enables the marking body to be implanted without having to rely on a stab incision in the skin at the point of entry of the cannula or anesthesia of the tissue concerned.

As a result of the overall system, the marking body can be applied together with a suitable implantation device that matches its dimensions. In particular, the implantation system as an overall system having both a marker body and an implantation device in the delivery state can contain the marker body already in the compressed state and in the cannula, so that the method step of compressing the marker body and There is no need to preload the implantation device for the user and the application is further simplified in this way.

According to the invention, a method for producing a marking body is also proposed. This has the following steps: Provision of a hose-like wire mesh, which is formed from 5 to 96 individual wires that are interwoven and

Constricting the wire mesh in a central longitudinal section, so that the wire mesh, starting from the central longitudinal section, widens in the longitudinal direction to both sides and forms two widened longitudinal sections. The method preferably has the following additional method steps:

Braiding of individual wires to form a hose, so that the individual wires alternately cross over and under at crossing points, the crossing points being arranged approximately on crossing point planes that extend transversely to a longitudinal axis of the hose, and - cutting off a hose section by laser cutting the wires at all

Crossing points of a parting plane, which is a crossing point plane, for providing the hose-like wire mesh. The hose-like wire mesh separated from the hose can then be shaped into the marking body. The individual wires are preferably welded to one another in pairs when they are separated.

The individual wires are preferably twisted with one another at intersection planes provided as parting planes, in that the respective two individual wires are looped around one another by at least 180 °, preferably 360 °, 540 ° or 720 °. The individual wires preferably cross over or under each other between the longitudinal ends of the hose-like wire mesh 8 to 12 times, preferably 9 to 11 times or 10 times. Correspondingly, every ninth to thirteenth, preferably every tenth, eleventh or twelfth plane of intersection of the hose braided from individual wires represents one Is the parting plane at which the individual wires are preferably twisted together in pairs.

A marker body of the type presented here is used for percutaneous marking in soft tissue, such as breast tissue, and for marking axillary lymph nodes after a previous lymph node biopsy.

Applications include marking suspicious tissue, marking lesions before or during chemotherapy, and marking a biopsy site. The location of a removed tumor can also be marked for better orientation for irradiation planning. The marker body can be used as part of a procedure as follows:

First, the marker body is implanted at a desired location by inserting a cannula of an implantation device with its distal end into body tissue to the desired implantation site and ejecting a marker body from the distal end of the cannula. Alternatively, the cannula tip of the implantation device can also be brought to the desired implantation site through a sheath already placed in the patient.

The body tissue can then be examined using an ultrasound imaging method, an ultrasound image of the marked tissue being made. In the ultrasound recording, the marking body can be recognized on the basis of a circular or X-shaped artifact.

The marker body is preferably used for markings in fatty tissue, muscle tissue, tumor tissue, breast tissue, liver tissue and / or lymph nodes, in particular the axillary lymph nodes.

Further advantages, features and details of the invention emerge from the following description of the preferred embodiments and the illustrative figures, of which:

1 shows a schematically illustrated marker body in a side view; FIG. 2: shows the marker body shown in FIG. 1 in an end view; FIG. 3: shows a schematically represented marking body in a side view;

FIG. 4: shows the marking body shown in FIG. 3 in an end view; FIG. Fig. 5: shows a schematically represented marking body in a side view;

FIG. 6: shows the marking body shown in FIG. 5 in an end view; FIG.

7: shows a schematically illustrated marker body in a side view; 8 shows the marking body shown in FIG. 7 in an end view;

9: different phases of a manufacturing method for manufacturing a

Marker body illustrated;

10A, B, C: show schematically an implantation system with a marking body and an implantation device; 11: shows a marking body with a support structure formed by 24 wires;

FIG. 12: shows the marker body shown in FIG. 11 in a further view in which the end face of the marker body is visible;

13 shows a side view of the marking body from FIGS. 11 and 12 in connection with a scale;

14: shows an end view of the marking body from FIGS. 11 and 12 in connection with a scale;

15 shows a perspective view of the marker body shown in FIGS. 3 and 4; 16 shows a marking body made from a wire mesh similar to the marking body shown in FIGS. 3, 4 and 15;

FIG. 17 shows a marking body made from a wire mesh similar to the marking body shown in FIG. 16 with an additional central sleeve;

18: a wire mesh as a section of a braided hose, which is used as a

Shows starting product for forming a marking body as shown in Figures 16 and 17;

19 shows a section of a hose braided from wire, from which three wire braids according to FIG. 18 can be produced by severing;

FIG. 20: shows the braided wire hose from FIG. 19, in which the wires have been severed at two points by means of a laser;

FIG. 21: a perspective view of the marking body shown in FIG. 16;

22 shows a further side view of the marking body shown in FIG. 16;

23a to 23h: show different cross-sectional shapes for struts of a marking body according to FIGS. 1 and 2; 24a to 24f: show different variants of how individual struts of the marking body from FIGS. 1 and 2 can be connected to one another at intersection points;

25a to 25f: show different variants of how free ends of two struts of a marking body according to FIGS. 1 and 2 can be connected; 26a and 26b: show plan views of an implantation device for a marking body according to FIGS. 1 to 25; 27 shows a further view of the implantation device from FIG. 26;

28 shows an ultrasound image with an artifact of the marking body viewed from the side; and

29: shows an ultrasound image with an artifact of the marking body in the longitudinal direction.

FIG. 1 shows a schematically illustrated marker body 100 in a side view. FIG. 2 shows the same marking body 100 in an end view.

The marking body 100 is formed by a reader-cut tube.

The marking body 100 is shown in the expanded state and has two widened longitudinal sections 102, 104 and a central longitudinal section 106, which is located between the two longitudinal sections 102, 104.

The two widened longitudinal sections 102, 104 each widen conically starting from the central longitudinal section 106. Correspondingly, the outside diameter of the widened longitudinal sections 102, 104 increases continuously starting from the central longitudinal section 106. At the respective longitudinal ends of the marking body 100, the outside diameter in the respective widened longitudinal section 102, 104 is maximum.

In the two widened longitudinal sections 102, 104, the marking body 100 has a grid-like support structure formed by struts 103 with a large number of intersection points 105. In order to bring the marking body 100 into its elastically compressed state, the lattice-like support structures in the two widened longitudinal sections 102, 104 can be compressed radially so that the meshes 108 of the respective support structure close in the direction of the longitudinal axis 110 of the marking body. The effective length of the marking body 100 is correspondingly greater in the compressed state than in the expanded state. In order to bring the marking body 100 into an elastically compressed state, a radial force of at least one Newton must be exerted on the marking body 100 in the two widened longitudinal sections 102, 104. The marking body 100 is thus designed in such a way that, in a compressed state, it exerts a radial force of approximately one Newton on the surrounding tissue and expands when the counterforce of the tissue is less than is a newton. In embodiments not shown here, the marker body has struts with a strut strength that is different from the strut strength of the struts 103, so that a comparatively greater radial force of, for example, at least 1.5 Newtons must be exerted on the marker body in order to compress it elastically.

In the central longitudinal section 106, the tube is not laser-cut and accordingly has a closed, sleeve-shaped support structure.

The marking body 100 is rotationally symmetrical with respect to its longitudinal axis 110. In the expanded state, the marker body 100 has a length L1 which is 7 mm. The tube from which the marker body 100 is formed has an inside diameter which is 0.458 mm, an outside diameter which is 0.762 mm, and a wall thickness which is 0.152 mm. In the central longitudinal section 106, the marking body 100 continues to have the original dimensions even after it has been laser-cut in the adjacent longitudinal sections 102, 104. The marking body 100 can be formed from a titanium alloy, in particular nitinol, for example.

In embodiments not shown here, marking bodies are formed by a tube which has different dimensions, but is otherwise laser-cut in such a way that a marking body, as described with reference to FIG. 1, is formed with a central longitudinal section and two widened longitudinal sections emanating from this. Such tubes can, for example, have an outer diameter that is between 0.6 mm and 0.08 mm, an inner diameter that is between 0.3 mm and 0.5 mm, and a wall thickness that is between 0.1 mm and 0.5 mm. In the widened longitudinal sections 102, 104, the maximum outer diameter A1 of the marking body 100 is 3.5 mm and, in alternative embodiments, can be between 3 mm and 4 mm, for example. In the central longitudinal section 106, the inner diameter 11 is 0.458 mm.

FIG. 3 shows a schematically illustrated marker body 100 in the expanded state in a side view. FIG. 4 shows the marking body 100 in an end view. The marking body 100 comprises a support structure formed by a wire mesh 301. The wires 308 extend from one longitudinal end of the marker body 100 to its other longitudinal end. On the way from one longitudinal end to the other longitudinal end, the wires 308 cross with other wires 308 and are in particular interwoven, that is, each of the wires 308 is routed alternately under and then over other wires 308 of the wire mesh 301. This creates a grid-like support structure with a large number of intersection points 310. With regard to the graphic representation in FIGS. 3 and 4, it should be noted that these intersection points 310, at which two wires 308 touch each other, are welded or twisted together , does not exactly reflect in detail. The points of intersection 310, at which two wires 308 each touch, can be designed, for example, as in the wire mesh of the marking body described and illustrated with reference to FIGS. 11 and 12, which is also formed by crossing wires.

In contrast to the wires 1102 of the marking body 100 described with reference to FIGS. 11 and 12, the wires 308 are welded to one another at the crossing points 310, that is to say connected to one another in a materially bonded manner. As an alternative or in addition to welding, the wires 308 can also be twisted with one another at the crossing points 310. In particular, the free ends 312 of the wires 308, which are located at the respective longitudinal ends 314, 316 of the marking body 100, are each welded to one or more free ends of further wires 308.

Like the marking body described with reference to FIGS. 1 and 2, the marking body 100 has widened longitudinal sections 302, 304 and a central longitudinal section 306 arranged between these widened longitudinal sections 302, 304. The outer diameter of the two widened longitudinal sections 302, 304 increase steadily starting from the central longitudinal section 306 in the direction of the longitudinal ends of the marking body 100. The outer diameter of the marking body 100 in the two longitudinal sections 302, 304 is correspondingly maximum at the longitudinal ends.

The wire mesh 301 comprises 24 wires which consist of nitinol and have a diameter of 0.12 mm. In alternative embodiments of the marking body, not shown here, the wire mesh comprises between 10 and 40 wires which are welded and / or twisted to one another at their intersection points. In the embodiments that are not shown here, the marking bodies have wire meshes that are shown in FIG Wires with diameters between 0.10 mm and 0.14 mm are formed. Wires made from titanium alloys other than nitinol can also be used.

The marking body 100 has a length L2 which is 6 mm, but in an alternative embodiment, not shown here, it can also be between 5 mm and 7 mm. The central longitudinal section 306 of the marking body 100 is provided with a sleeve, in particular a nitinol sleeve 318, which compresses the wire mesh 301 in the central longitudinal section 306 to a defined outer diameter.

The maximum outer diameter A2 of the marking body in the two widened longitudinal sections 302, 304 is 4 mm and in alternative embodiments, not shown here, can be between 3.5 mm and 4.5 mm.

In order to bring the marking body 100 from the expanded state into an elastically compressed state, a radial force of at least one Newton must be exerted on the marking body 100. The marking body 100 is thus designed in such a way that, in a compressed state, it exerts a radial force of approximately one Newton on the surrounding tissue and expands when the counterforce of the tissue is less than one Newton.

In alternative embodiments, not shown here, the self-expanding marking body 100 can have more wires and correspondingly more intersection points, so that it is comparatively stiffer. Correspondingly, a comparatively greater radial force is then necessary in order to bring the marking body into an elastically compressed state. Likewise, the number of wires can be smaller in alternative embodiments, not shown here, in order to realize a marking body which changes into its elastically compressed state under an exerted radial force of less than one Newton. The expanded marking body 100 shown in a side view in FIG. 5 has a helical support structure. In FIG. 6, the marking body 100 is shown in an end view.

A central longitudinal section 502 comprises one turn, but in alternative embodiments not shown here it can also comprise several turns, preferably with a constant outer diameter. On both sides of the central longitudinal section 502 are each followed by a widened longitudinal section 506, 508 along the longitudinal axis 504 of the marking body 100, the outer diameter of which increases steadily starting from the central longitudinal section 502. That is, starting from the central longitudinal section, the outer diameter of the marking body 100 increases from turn to turn. In the expanded state of the marking body 100 shown here, the spiral-shaped support structure has an angle W1 which is 30 °. The marking body 100 can be brought into an elastically compressed state in that the helical support structure is pulled apart, as a result of which the angle is reduced. In order to bring the marking body 100 into an elastically compressed state, a radial force of at least one Newton must be exerted on it. The marking body 100 is thus designed in such a way that, in a compressed state, it exerts a radial force of approximately one Newton on the surrounding tissue and expands when the counterforce of the tissue is less than one Newton.

The marking body 100 has a length L3 which is 6 mm, but in alternative embodiments not shown here, it can also be between 5 mm and 7 mm.

The maximum outer diameter A3 of the marking body 100 in the widened longitudinal sections 506, 508 is 5 mm and in alternative embodiments, not shown here, can also be between 4 mm and 6 mm, but in particular also less than 4 mm. FIG. 7 shows an expanded marking body 100 in a side view. In FIG. 8, the marking body 100 is shown in an end view.

The marking body 100 has two widened longitudinal sections 702, 704 and a central longitudinal section 706 which is located between the two widened longitudinal sections 702, 704. Like the marking body described with reference to FIGS. 1 and 2, the marking body 100 is also formed from a laser-cut tube. In particular, the marking body 100 is laser-cut in the two widened longitudinal sections 702, 704 and not in the central longitudinal section 706. Correspondingly, the marking body 100 in the expanded state has a grid-like support structure in the two widened longitudinal sections 702, 704, whereas the support structure in the central longitudinal section 706 is closed and sleeve-shaped. In contrast to the marking body described with reference to FIGS. 1 and 2, the marking body 100 does not expand continuously in the two expanded longitudinal sections 702, 704 up to the longitudinal ends of the marking body 100, but only starting from the central longitudinal section up to approximately the Center of the respective widened longitudinal section 702, 704. Thereafter, the outer diameter of the marking body in the respective widened longitudinal section 702, 704 in the direction of the respective longitudinal end of the marking body 100 is essentially constant.

In alternative embodiments, not shown here, the outer diameter of the marking body is not constant between approximately the middle of the respective widened longitudinal section in the direction of the respective longitudinal end of the marking body, but rather decreases, so that the shape of the respective widened longitudinal section is at least approximately spherical or elliptical.

The marking body 100 has a length L4 which is 7 mm, but in alternative embodiments, not shown here, is between 4 mm and 10 mm. In the central longitudinal section 706, the dimensions of the marking body 100 correspond to the original dimensions of the tube from which the marking body 100 is formed. In the central longitudinal section 706, the marking body 100 has an outside diameter which is 0.762 mm, an inside diameter which is 0.458 mm, and a wall thickness which is 0.152 mm. In alternative embodiments of the marking body, not shown here, the latter has an outer diameter in the central longitudinal section that is between 0.6 mm and 0.08 mm, an inner diameter that is between 0.3 mm and 0.5 mm, and a wall thickness, which is between 0.1 mm and 0.5 mm. In the two widened longitudinal sections 702, 704, the maximum outer diameter A4 of the marking body 100 is 3.5 mm, but in alternative embodiments not shown here it can also be between 3 mm and 4 mm. The inner diameter I2 of the marking body 100 in the central longitudinal section 706 is 0.458 mm. In order to compress the marking body 100 elastically, a radial force of at least one Newton must be exerted on it. When the marking body 100 is implanted in tissue, the latter changes automatically into its expanded state and maintains this when that exerted by the tissue on the marking body 100 Radial force is less than one Newton. The marking body 100 is thus designed in such a way that, in a compressed state, it exerts a radial force of approximately one Newton on the surrounding tissue and expands when the counterforce of the tissue is less than one Newton. FIG. 9 illustrates various phases of a production method for producing a marking body which has a support structure formed by a wire mesh. For example, a marking body as described with reference to FIGS. 3 and 4 can be produced in accordance with the method described below. First of all, in a step S1, a hose-like wire mesh is provided which, for example, can have between 20 and 40 individual wires which are braided with one another and consequently cross at intersection points. At the crossing points, the wires are preferably cohesively connected to one another or twisted with one another. Sleeves are pushed onto the hose-like wire mesh in such a way that a section of the wire mesh is exposed between the two sleeves and the two sleeves are aligned coaxially with one another.

The sleeves are then moved towards one another in the longitudinal direction of the hose-like wire mesh, to be precise without a relative movement occurring between the respective sleeve and the wire mesh enclosed by it. As a result, the wire mesh exposed between the sleeves is compressed in the longitudinal direction and expands in the radial direction (step S2).

The two sleeves can be moved towards one another so far that the wire mesh is partially turned inside (step S3). In addition, the wire mesh is constricted in a central longitudinal section in the middle of the exposed wire mesh, for example by winding a nitinol wire around the wire mesh (step S4). This can be done before or after widening and, if necessary, everting.

The wire mesh can then cut on both sides of the central longitudinal section perpendicular to the longitudinal direction of the wire mesh and the cut off part, for example the everted part of the wire mesh can be removed. The cutting is preferably carried out at already existing crossing points of the wire mesh, which lie on a plane running transversely to the longitudinal direction of the wire mesh. As a result, the longitudinal ends of the wires are connected to one another in pairs. If the cutting does not take place at existing crossing points and thus free ends of the wire mesh are created, these can be twisted and / or welded together.

Figure 10A shows an implantation system 1000 with a marker body 100 of an implantation device 1004. Here, the marker body 100 is in the preloaded state, ie with a compressed support structure, within the cannula 1006 of the implantation device 1004. This state of the implantation system 1000 represents a typical delivery state in which the implantation system 1000 is made available ready for use by the user, for example a surgeon. The implantation part 1008 of the implantation device 1004 essentially consists of a cannula 1006 which has a cannula tip 1012 at its distal end, i.e. on the side facing away from the handle 1010. In this area within the cannula 1006, shortly before the exit at the cannula tip 1012, the marker body 100 is generally in the precharged state. The cannula 1006 can in particular be formed from a suitable metal.

The cannula 1006 has a length LKA which, for example, can assume a value between 25 mm and 200 mm, preferably between 50 mm and 150 mm. The length LKA of the cannula 1006 has an influence on the range of the implantation device 1004 with regard to the accessibility of tissue locations to be identified in the body of a patient. The longer cannulas are used when using adjustment aids, for example stereotaxics.

The implantation device 1004 has a handpiece 1010 and an implantation part 1008. The handpiece 1010 has a handpiece housing 1014 and a sliding element 1016, which can be made of a suitable plastic, for example. The sliding element 1016 is connected to the handpiece housing 1014, but is movable in the axial direction of the cannula 1006 relative to the handpiece housing 1014. Consequently the sliding element 1016 can be moved on a straight, guided sliding path between a preloading position 1020 and a discharge position 1020.

This movement is transmitted from the sliding element 1016 via a dispensing element 1018 connected to the sliding element 1016, which can be formed, for example, via a wire or a sufficiently stable plastic fiber, into the distal area facing away from the handpiece 1010. Thus, when the sliding element 1016 is moved into the deployment position 1020, the preloaded marking body 100 can be deployed by a sliding movement of the deployment element 1018 out of the cannula 1006 at the tissue location to be identified at the distal end of the cannula 1006. This is achieved in that the deployment element 1018, which is aligned coaxially to the cannula 1006, moves in the direction of the cannula tip 1012 and thus pushes the preloaded marker body 100 past the cannula tip 1012 out of the cannula 1006.

In FIG. 10B, detail B from FIG. 10A, namely a detailed view of the implantation system 1000 in the preloaded state, is shown in the area of the cannula tip 1012. In this view, in particular, the marking body 100 can be seen in the compressed state, which, from the perspective of the handpiece 1010, is located behind the dispensing element 1018 and in front of the cannula tip 1012 within the cannula 1006. Due to its prestress, the marking body retains its position in the cannula 1006 and cannot fall out of its own accord. Because of this property, additional features or devices for fixing the marking body 100 within the cannula 1006 can be dispensed with.

FIG. 10C again shows, as detail C from FIG. 10B, a further detailed, schematic view of the cannula 1006. In this view, the distal end of the dispensing element 1018 within the cannula 1006 can be seen. The outer diameter DKA and the inner diameter DKI of the cannula 1006 are also marked.

The inner diameter DKI of the cannula 1006, together with the cannula length LKA, describes the size of the inner cavity formed by the cannula 1006 and at the same time limits the maximum possible diameter DM of the marking body 100 in the compressed state or, if applicable, the maximum possible diameter DK of the at least one clamp 105, in order to ensure a patency or mobility of the marking body 100 within the cannula 1006 during pre-loading and deployment guarantee. An inner diameter DKI of less than 1.1 mm, particularly preferably 1.0 mm, has proven to be preferred.

The outer diameter DKA of the cannula 1006 describes the diameter of the outer cannula wall. With an increasing outside diameter BKA, assuming a constant, as small as possible cannula wall thickness, the inside diameter DKI of the cannula 1006 and thus the maximum possible outside diameter of a marker body 100 to be implanted increases at the same time Invasiveness or damage to skin and tissue when performing the implantation. A sufficiently small outer diameter DKA ensures the possibility of percutaneous implantation of the marking body 100 without having to rely on a stab incision of the skin at the entry point of the cannula 1006 or an anesthetic of the affected tissue. An outer diameter DKA between 1 mm and 1.5 mm, particularly preferably 1.2 mm, has proven to be preferred. FIG. 11 shows an expanded marking body 100 in a side view. FIG. 12 shows the marking body 100 in a further view in which one of the end faces of the marking body 100 is visible.

The marker body 100 has a support structure formed by twenty-four individual, preformed wires 1102. The support structure is designed as a wire mesh 1104. The wire mesh 1104, corresponding to the wire mesh 301 of the marking body 100 described with reference to FIGS. 3 and 4, is formed by crossing wires 1102. The wires of the wire meshes 1104 and 301 can already be preformed, elastic wires.

The wires 1102 run from one longitudinal end 1106 of the marking body 100 to the opposite longitudinal end 1108 of the marking body 100 in a helical manner around the longitudinal axis of the marking body 100. The wires 1102 are on the way from one longitudinal end 1106 to the other longitudinal end 1108 of the marking body several times under and over other wires the support structure are interwoven in such a way that they form the wire mesh 1104. Crossing points 1110 arise at those points of the wire mesh 1104 where wires 1102 are routed under or over other wires 1102. The wires 1102 of the wire mesh 1104 are not materially connected to one another at the crossing points 1110, but just touch each other. borrowed. In alternative exemplary embodiments, not shown here, the wires can be welded to one another at the crossing points, as is the case, for example, with the marking body described with reference to FIGS. 3 and 4.

The wires 1102 are guided diagonally from one longitudinal end 1106 to the other longitudinal end 1108 of the marking body 100 in such a way that the marking body 100 is constricted in the central longitudinal section 1112.

Starting from the central longitudinal section 1112, the outer diameter of the marking body 100 increases steadily on both sides, so that the marking body 100 has two conical, widened longitudinal sections 1114, 1116. The outer diameter of the marking body 100 in the widened longitudinal sections 1114, 1116 is at a maximum at each of the two longitudinal ends 1106, 1108 of the marking body 100.

The angle at which the marking body 100 widens in the expanded state in the widened longitudinal sections 1114, 1116 can be, for example, 30 ° and in particular between 25 ° and 35 °, starting from the central axis. The wires 1104 are formed from nitinol.

At the free ends 1118 of the wires 1102, which are located at the longitudinal ends 1106, 1108 of the marking body 100, two adjacent wires 1102 are twisted and welded together. The welding results in welding beads 1120 with a welding bead diameter Ds that is greater than a difference in diameter between the inside diameter of the DKI of the cannula and the outside diameter D _{A of} the dispensing element 1018. This prevents the marking body, in particular a welding bead of the Marking body, clamped between the distal end portion of the dispensing element 1018 and the inner wall of the cannula. For this purpose, the distal end of the dispensing element 1018 is also preferably sharp-edged, because round or chamfered edges could cause the marking body to jam, so that the marking body cannot be implanted.

The marking body 100 is designed such that a radial force of at least one Newton has to be exerted on the marking body 100 in order to compress it to a diameter of less than 1.5 mm. The marking body 100 can have a sleeve, for example a nitinol sleeve 1122, which is arranged in the central longitudinal section 1112 as in the case of the marking body 100 described with reference to FIGS. 3 and 4. A corresponding marking body 100 'is shown in FIG. The dimensions of the marking body 100 or 100 'result from FIGS. 13, 14, 16 and 17, which show the marking body 100 in its expanded state in connection with a scale. In its expanded state, the marker body is approximately 6 mm to 7 mm long (see FIG. 13) and has a maximum external diameter of approximately 5 mm (see FIG. 14). FIG. 15 is an idealized, perspective illustration of the marking body 100. The illustration in FIG. 15 shows the basic structure, but is idealized with regard to the illustration of the intersection points and the free, interconnected longitudinal ends 1118 of the wires 1102.

As can be seen from FIG. 16, the marking body 100 preferably has a length L which is between 5 mm and 8 mm. The outside diameter D in the fully expanded state is between 4mm and 6mm. The constricted, central longitudinal section 1112 has a diameter d which is less than 1.5 mm. The diameter of the individual wires 1102 is preferably slightly less than 0.1 mm. The welding beads 1120 at the free ends 1118 of the wires have a diameter which is greater than 0.1 mm and preferably at least 0.12 mm. The marking body 100 is therefore suitable for use with an implantation device 1004, in which the difference between an inner cannula diameter DKI and an outer ring element outer diameter DA is at most 0.1 mm, also taking into account the manufacturing tolerances. FIG. 16 also shows that the free longitudinal ends 1118 of the wires 1102 are not only welded to one another, but also twisted together. In combination with one another, this ensures that the longitudinal ends of the wires that are connected to one another do not separate from one another, because the forces caused by the prestress in the cannula then do not act completely on the welding point, but are partially or completely absorbed by the twist.

In contrast to what is idealized in the figures, the longitudinal ends of the individual wires 1102 do not all lie exactly in a (dividing) plane 1212 (see FIGS 20), but are preferably alternately slightly offset in the longitudinal direction with respect to such an idealized plane. This has the advantageous effect that the marking body 100 can be compressed better at its longitudinal ends 1118 because the welding beads 1120 are not all adjacent to one another, but are at least partially offset from one another in the longitudinal direction of the marking body 100.

In its fully expanded state, its widened longitudinal sections 1114 and 1116 widen with respect to a longitudinal axis of the marking body 100 at an angle α, which is preferably between 30 ° and 45 °.

In the constricted, central longitudinal section, the marking body 100 ‘can have a sleeve 1122, which causes the marking body 100‘ to remain compressed in this central longitudinal section 1112 in any case. The sleeve 1122 can be made of the same material - namely preferably nitinol - as the individual wires 1102. However, the sleeve 1122 can preferably also be made of a radio-opaque material, for example gold. The sleeve 1122 is preferably welded to at least one of the wires 1102 by means of at least one welding point 1124 and is thus secured against displacement. If a sleeve 1122 is provided, the wire ends need not be welded.

The dimensions of the marking body 100 with a central sleeve 1122 correspond approximately to those of the marking body 100. Accordingly, the length L2 of the marking body 100 is preferably between 5 mm and 10 mm. The maximum diameter D2 of the marking body 100 ‘in the fully expanded state is preferably between 4 mm and 6 mm. The central sleeve 1122 preferably has a diameter d2 which is less than 2 mm, preferably less than 1.8 mm and particularly preferably less than 1.0 mm. The length h of the sleeve 1122 is preferably less than 2 mm; see Figure 17.

The marking body 100 or the marking body 100 ′ are each preferably formed from a wire mesh 1200, as is shown by way of example in FIG. FIG. 18 shows a wire mesh 1200 as a section of a braided wire hose 1202 (see FIG. 19), which in the example shown is braided from 24 individual wires. The wire mesh 1200 that will later become the marking body 100 or 100 'is formed by 24 individual wires 1102, which cross each other nine times between their longitudinal ends 1118 and which are twisted and welded in pairs at their longitudinal ends 1118 so that the wire mesh 1200 is attached to the Longitudinal ends 1118 of the wires 1102 each have weld beads 1120. As can be seen from FIG. 18, the longitudinal ends 1118 of the wires 1102 connected to one another are not only welded to one another, but also twisted together.

In another embodiment, the marking body 100 ′ can be manufactured from a simple wire mesh 1200 without twists 1206. In this embodiment, the wire ends do not have to be welded together, since the sleeve 1122 holds the braid stable.

In order to produce a wire mesh 1200 as shown in FIG. 18, a wire hose 1202 as shown in FIG. 19 is first produced. To produce the hose 1202, for example, 24 individual wires 1102 are braided with one another so that they alternately cross over and under one another at intersection points 1110. In this way, intersection planes 1210 are created which extend transversely to a longitudinal direction of the hose 1202. After the individual wires 1102 have crossed each other nine times in pairs, two individual wires are twisted with one another so that twists 1206 are produced. The wire hose 1202 thus forms intersection planes 1210, which alternate with parting planes 1212, at which a respective wire mesh 1200 is to be separated from the wire hose 1202. In the example shown, nine intersection planes 1210 are each followed by a separating plane 1212. In the separating planes, the wires 1102 are completely looped around each other twice in pairs, so that a wrap angle of 720 ° results. In other exemplary embodiments, not shown, the wrap angle can also be only 360 ° or also 540 °.

FIG. 20 shows the hose 1202 formed by the wires 1102, the hose 1202 having been cut at two separation points 1214 by means of a laser beam. The separating points 1214 are located exactly in a separating plane 1212, that is to say where the twists 1206 are located. The welding beads 1120 are produced by the laser cutting, so that the then free longitudinal ends 1118 of the wires 1102 that are connected to one another in pairs are connected to one another both by twisting and by laser welding. FIGS. 21 and 22 once again show perspective views of a marking body 100. The individual struts can have different diameters and different cross-sectional shapes. Figures 23a to 23h show different cross-sectional shapes. The struts can, for example, be implemented as round solid wire and have a cross section as shown in FIG. 23a. The struts preferably consist of a hollow wire - that is, a type of tube - which can have a cross section as shown in FIG. 23b. Such a hollow wire has the advantage that it reflects sound particularly well due to the acoustic impedance differences between the material of the wire wall and the hollow interior. FIGS. 23c and 23d illustrate that the cross-sectional shape can also be square, in particular rectangular. 23e and 23f show a triangular cross-sectional shape for struts in the form of solid material (FIG. 23e) or as hollow struts (FIG. 23f). FIGS. 23g and 23h illustrate that struts can basically each have any prismatic cross-sectional shape, for example hexagonal as shown in FIGS. 23g and 23h.

Since the marking body 100 is preferably made from a wire mesh, the wires typically simply touch one another at the crossing points. A crossing point can then look like this is shown by way of example in FIG. 24a. At such a crossing point, a fixed connection between two crossing wires can be made by welding. FIG. 24b illustrates this with the aid of a weld point 118 on the intersection point. If the struts are not intertwined but simply touch each other laterally in an arc, as shown in Figure 24c, a stable marking body can also be produced by connecting the touching struts by welding, as shown in Figure 24d is. A spot weld 118 is also shown here. Finally, the struts can also be twisted at the crossing points. FIG. 24e shows a twist in which the struts are looped around one another through 360 ° and then connected to one another with a weld point 118; see Figure 24f. Instead of a twist by 360 °, a twist by 180 ° is also sufficient. The picture that then appears looks similar to FIG. 24c, only that the struts are then hooked into one another. FIGS. 25a to 25f illustrate that struts can be connected not only at intersection points but also at their free longitudinal ends 112 by welding (FIG. 25b), by twisting (FIGS. 25c and 25e) or by twisting and welding (FIGS. 25d and 25f). The welding of the struts 103 at their free longitudinal ends 112 results in welding beads 120, which are typically larger Have diameters than a single strut 103 or a wire that forms a strut 103.

Finally, FIGS. 26 and 27 show an implantation device 1004 for implanting a marking body 100. As already explained in connection with FIG. 10, the implantation device 1004 has a hand part 1010 and an implantation part 1008. Part of the implantation part 1008 is the cannula 1006, in which the marker body 100 is initially located.

FIG. 26a shows the implantation device 1004 with the sliding element 1016 and the dispensing element 1018 in the preloading position. The implantation system 1000 is thus prepared for use and contains the marking body 100 (not visible because it is arranged in the cannula 1006). A protective cover 1024 is provided to protect against injuries. FIG. 26b shows the implantation device 1004 with the sliding element 1016 and the dispensing element 1018 in the dispensing position in which the marking body is ejected. A cannula tip 1012 at the distal end of the cannula 1006 is ground in such a way that it allows percutaneous implantation of the marking body 1100 by piercing the cannula 1006 into body tissue. The cannula 1006 is preferably made of stainless steel.

To eject the marking body 100 from the cannula 1006, a displaceable dispensing element 1018 is provided that can be actuated from the handle 1010 by means of the sliding element 1016.

By means of the implantation device, a marker body of the type presented here can be implanted for percutaneous marking in soft tissue such as breast tissue or axillary lymph nodes after a previous lymph node biopsy. Applications include marking suspicious tissue, marking lesions before or during chemotherapy, and marking a biopsy site. The location of a removed tumor can also be marked for better orientation for irradiation planning.

The marker body is used, for example, as follows in the course of an operation: First, the marker body is implanted at a desired location by the distal end 1012 of the cannula 1006 of the implantation device 1004 piercing into body tissue to the desired implantation site and a marker body 100 being ejected from the distal end 1012 of the cannula 1006. The body tissue can then be examined using an ultrasound imaging method, an ultrasound image of the marked tissue being made. In the ultrasound recording, the marking body can be recognized on the basis of a circular artifact 1300 or X-shaped artifact 1302; see Figures 28 and 29.

Reference list

100, marker body

102, 104 widened longitudinal sections 103 struts 105 intersection points

106 central longitudinal section 108 mesh 110 longitudinal axis 118 welding point 120 welding bead L1 length of the marking body A1 maximum outer diameter of the marking body in the widened longitudinal sections

11 Inner diameter of the marking body in the central longitudinal section 301 wire mesh

302, 304 expanded longitudinal sections 306 central longitudinal section 308 wires 310 crossing points 312 free ends of the wires

L2 length of the marker body A2 maximum outer diameter of the marker body in the expanded

Longitudinal sections

502 central longitudinal section 504 longitudinal axis of the marking body

506, 508 widened longitudinal sections W1 angle of the spiral-shaped support structure L3 length of the marking body A3 maximum outside diameter maximum outside diameter of the marking body in the widened longitudinal sections

702,704 expanded longitudinal sections

706 central longitudinal section

L4 length of the marker body

A4 maximum outer diameter, maximum outer diameter of the marking body in the expanded longitudinal sections

I2 inner diameter of the marking body in the central longitudinal section 51 Provision of a hose-like wire mesh

52 Compression of the tubular wire mesh in its longitudinal direction

53 partial inversion of the wire mesh

54 Constriction of the wire mesh in a central longitudinal section of the DKI cannula inside diameter

DKA cannula outer diameter

BKA outer diameter

LKA cannula length

1000 implantation system 1004 implantation device

1006 cannula

1008 implant part

1010 handle

1012 cannula tip 1014 handpiece housing

1016 sliding element

1018 application element

1020 preload position

1022 application position 1024 protective cover

1102 wires

1104 wire mesh

1106, 1108 longitudinal ends of the marker body 1110 intersection 1112 central longitudinal section

1114, 1116 widened longitudinal sections 1118 longitudinal ends of the struts

1120 beads of sweat

1122 sleeve 1124 spot weld

1200 wire mesh

1202 wire hose 2

1206 twist

1210 Intersection planes 1212 Parting plane

1214 separation points

1300 circular artifact 1302 X-shaped artifact

Claims

Expectations

Marking body (100) for marking body tissue, the

Is at least approximately rotationally symmetrical with respect to its longitudinal axis (110) and is formed by interconnected, elastic and preformed metal struts (103) and can assume a radially compressed and a radially expanded state, characterized in that the marking body (100) in its expanded state is constricted in a central longitudinal section (106; 306; 706; 1112) and, starting from the central longitudinal section (106; 306; 706; 1112), widens in the longitudinal direction to both sides and two widened longitudinal sections (102, 104; 302 , 304; 506, 508; 702, 704; 1114, 1116), the maximum outer diameter (A1; A2; A3; A4) of which is two to twenty times larger than the outer diameter (BKA) of the central longitudinal section (106; 306; 706 ; 1112) in the expanded state of the marking body (100), the marking body (100) at least in the expanded longitudinal sections (102, 104; 302, 304; 506, 508; 702, 704; 1114, 1116) is formed in the circumferential direction from 5 to 96 struts (103) which in the compressed state of the marking body (100) run essentially in its longitudinal direction and which are non-positively, positively and / or cohesively connected to one another.

Marking body (100) according to claim 1, characterized in that the struts (103) of the marking body (100) are formed by 5 to 96 wires (308; 1102), each extending from one to the other longitudinal end (1106, 1108) of the marking body (100) extend and cross each other several times and in this way form a lattice-like support structure with a large number of crossing points (105; 310; 1110). 3. Marking body (100) according to claim 1 or 2, characterized in that the struts (103) of the marking body (100) at the intersection points (105; 310; 1110) are materially connected to one another, in particular welded.

4. marking body (100) according to at least one of claims 1 to 3, characterized in that the struts (103) of the marking body (100) at their

Longitudinal ends (1106, 1108) are twisted together.

5. Marking body (100) according to at least one of claims 1 to 4, characterized in that the struts (103) of the marking body (100) are connected to one another in pairs at their respective longitudinal ends (1106, 1108), in particular welded and / or twisted are.

6. marking body (100) according to at least one of claims 1 to 5, characterized in that the outer diameter (BKA) of the marking body (100) in its expanded state starting from the central longitudinal section (106; 306; 706; 1112) in the longitudinal direction steadily increases towards both longitudinal ends (1106, 1108) and the marking body (100) has its maximum diameter at its two longitudinal ends (1106, 1108).

7. Marking body (100) according to at least one of claims 1 to 5, characterized in that the outer diameter (BKA) of the marking body (100) in its expanded state starting from the central longitudinal section (106; 306; 706; 1112) in the longitudinal direction initially increased towards both longitudinal ends (1106, 1108) and decreased again towards the longitudinal ends (1106, 1108) so that the marking body (100) has its maximum diameter at a distance from its respective longitudinal end (1106, 1108)

8. marking body (100) according to at least one of claims 1 to 7, characterized in that the struts (103) of the marking body (100) from a

Titanium alloy, in particular consist of nitinol.

9. Marking body (100) according to at least one of claims 1 to 8, characterized in that the central longitudinal section (106; 306; 706; 1112) is provided with a sleeve (1122) which the central longitudinal section (106; 306; 706 ; 1112) compressed to a minimum diameter. 10. Marking body (100) according to at least one of claims 1 to 9, in which at least one strut (103) is at least partially hollow.

11. Implantation system (1000) with a marker body (100) according to any one of claims 1-10 and an implantation device (1004) with a cannula (1006), wherein the marker body (100) is located inside the cannula (1006) and by actuating the Implantation device (1004) can be moved out of the cannula (1006).

12. Implantation system (1000) according to claim 11, characterized in that the implantation system (1000) for use within a vacuum biopsy unit, in particular a vacuum biopsy sheath, is designed with a cannula (1006) which has a lateral opening for the application of a marker body ( 100).

13. A method for producing a marking body (100) for marking body tissue, the method comprising the steps of: - providing a hose-like wire mesh (200; 301; 1104; 1200) which has two longitudinal ends and 5 to 96 interwoven individual wires (308; 1102) is formed, and

Constricting the wire mesh (200; 301; 1104; 1200) in a central longitudinal section (106; 306; 706; 1112) so that the wire mesh (200; 301; 1104; 1200) starts from the central longitudinal section (106; 306;

706; 1112) widens in the longitudinal direction on both sides and forms two widened longitudinal sections (102, 104; 302, 304; 506, 508; 702, 704; 1114, 1116).

14. The method according to claim 13, which has the further steps: severing, in particular cutting, the wire mesh (200; 301;

1104; 1200) in a plane running transversely to the longitudinal direction of the wire mesh (200; 301; 1104; 1200), and removing the severed part of the wire mesh (200; 301; 1104; 1200). 15. The method of claim 14, comprising the further step of:

Joining of free ends (312; 1118) of the wire mesh (200; 301; 1104; 1200) created by the severing, wherein the joining can take place before or after severing by twisting and / or before, during or after severing by weld.