Biopsy instrument for taking tissue samples

Abstract

The invention relates to a biopsy instrument for taking tissue samples under MRI visualization, comprising a biopsy needle (2) which is secured to a handling device (1), can be inserted into the tissue to be examined and is provided, in its distal end region, with a sample-receiving chamber (4) which extends in the longitudinal direction of the biopsy needle, is laterally open, and over which a cutting sleeve (5), which tightly surrounds the biopsy needle (2) and is distally provided with a cutting edge (6), is slidable in order to cut off the tissue sample, which, after insertion of the biopsy needle, has entered the sample-receiving chamber (4) of the biopsy needle (2), from the surrounding tissue, wherein the instrument as a whole consists of materials which are suitable for MRI visualization. The aim of the invention is to develop a biopsy instrument of this type in such a way that it can be identified more precisely under MRI imaging where the tissue sample is supposed to be taken. This aim is achieved in that, in the sample-receiving chamber (4) of the biopsy needle (2), MRI visualization markers are located in the area of the distal end of the chamber and in the area of the proximal end of the chamber, which markers are designed as polymer layers applied to the axial end faces (4 a, 4 b) of the sample-receiving chamber (4).

Description

[0001] Biopsy device for taking tissue samples

[0002] The invention relates to a biopsy device for taking tissue samples under MRI visualization, with a biopsy needle which is attached to a handling device and can be inserted into the tissue to be examined, which is provided in its distal end region with a laterally open sample receiving space which extends in the longitudinal direction thereof, over which a cutting sleeve which closely surrounds the biopsy needle and is provided distally with a cutting edge can be displaced in order to cut off the tissue sample which has penetrated into the sample receiving space of the biopsy needle after the biopsy needle has been inserted from the surrounding tissue, wherein the biopsy device as a whole is made of materials which are suitable for MRI visualization.

[0003] Such a biopsy device is known, for example, from DE 100 42 519 C1, where all its functions are described. It is important that the biopsy needle and the surrounding cutting sleeve, on the one hand, and the handling device with the drive devices for the cutting sleeve, on the other, are made of non-magnetic materials to prevent unwanted artifacts from interfering with MRI imaging.

[0004] Due to these special properties, handling such a biopsy device for targeted tissue sampling is not easy, as MRI imaging often does not adequately reveal where exactly the tissue sample is being taken within the target area. Therefore, the object of the invention is to further develop the biopsy device of the type mentioned above so that MRI imaging allows for more precise identification of where the tissue sample is being taken.

[0005] To achieve this objective, the invention proposes, based on the biopsy device of the type mentioned above, that MRI visualization markers be arranged in the sample receiving chamber of the biopsy needle, on the one hand in the region of its distal end and on the other hand in the region of its proximal end. These markers are designed as layers applied to the axial end surfaces of the sample receiving chamber. Because these MRI visualization markers are located precisely at the beginning and end of the sample receiving chamber, one can see very precisely where the tissue sample is being taken when handling the device under MRI visualization.

[0006] According to the state of the art (cf. DE 10 2011 101 860 A1), it is generally known to apply MRI markers in the form of thin-film MRI contrast coatings to medical devices that are inserted into the body, e.g., catheters, cannulas, or endoscopes. However, these thin-film MRI contrast coatings have an extremely low layer thickness and therefore must be applied by physical or chemical vapor deposition (PVD or CVD processes). However, the application of such thin-film MRI contrast coatings to the very small end surfaces of the sample receiving chamber of biopsy devices of the type mentioned above would be difficult and far too costly, especially since these biopsy devices are usually requested and provided as disposable products.In addition, given the very small end surfaces of the sample receiving chamber, it is questionable whether a thin-film MRI contrast coating can truly achieve a sufficient marking effect for MRI visualization on these very small surfaces. Because, according to the teachings of the invention, the MRI visualization markers are applied to surfaces where a thicker coating would not be detrimental, it is possible to use, for example, an inexpensive polymer as the MRI contrast agent. If necessary, this polymer can be mixed with suitable MRI markers, e.g., nano-iron particles or similar. This polymer can be applied to the end surfaces of the sample receiving chamber in a sufficiently thick layer without significantly reducing its size.

[0007] A preferred embodiment of the biopsy device according to the invention provides that the polymer layers used as MRI visualization markers are 0.1 mm to 2 mm, preferably 0.2 to 1 mm, thick. This easily provides the MRI visualization markers with a volume sufficient for visualization with an MRI device.

[0008] For example, biocompatible cyanoacrylates, which can be self-cured or cured by UV light, have proven to be cost-effective polymers for the production of MRI visualization markers.

[0009] An embodiment of the invention is explained in more detail below with reference to the accompanying drawings.

[0010] They show:

[0011] Figure 1: schematically shows a biopsy device according to the invention in perspective view;

[0012] Figure 1 a: enlarged detail A of Figure 1 , ie the distal end section of the biopsy needle;

[0013] Figures 2 and 2a: a plan view of Figures 1 and 1a;

[0014] Figures 3 and 3a: a side view of Figures 1 and 1a

[0015] In the drawing, the handling device of the biopsy device according to the invention is designated by reference numeral 1. Attached to this handling device 1 is a biopsy needle 2, which is provided at its distal end with a beveled cutting edge 3 that cuts into the tissue to be examined when the biopsy needle is inserted. Furthermore, the biopsy needle 2 is provided in its distal end region with a laterally open sample receiving chamber 4 extending longitudinally. A cutting sleeve 6, which closely surrounds the biopsy needle 2 and is provided distally with a cutting edge 5, can be pushed over this sample receiving chamber 4.

[0016] This cutting sleeve 6 is connected to a spring drive, not shown in detail in the drawing, arranged in the handling device 1, which, when triggered, moves the cutting sleeve 6 at very high speed over the biopsy needle 2 into its distal end region.

[0017] All previously mentioned components of the biopsy device according to the invention are made of non-magnetic materials, i.e. materials that cannot interfere with MRI visualization during the biopsy.

[0018] In order to make the beginning and end of the sample receiving chamber 4 precisely visible when using the biopsy device under MRI visualization, the teaching of the invention provides that MRI visualization markers are arranged in the sample receiving chamber 4 of the biopsy needle 2, on the one hand in the region of its distal end and on the other hand in the region of its proximal end, which MRI visualization markers are designed as polymer layers applied to the axial end surfaces of the sample receiving chamber 4.

[0019] These polymer layers serving as MRI visualization markers are between 0.1 mm and 2 mm thick, but preferably 0.2 to 1 mm thick, and consist, for example, of a polymer infused with MRI markers, which can thus be perceived relatively accurately and, with correct positioning, as an artifact during MRI visualization. Of course, certain other materials are also suitable for MRI visualization.

[0020] The concentration of particles in the polymer (e.g. nanoiron or similar) can be used to influence the intensity of the resulting artifacts to ensure optimal visibility of the biopsy notch. When taking a tissue sample under MRI visualization, the biopsy needle 2 is first inserted into the tissue to be examined using the handling device 1 until the sample receiving chamber 4 has reached the area of ​​the tissue to be examined from which the tissue sample is to be taken. The tissue to be examined penetrates the side into the laterally open sample receiving chamber 4. Because the beginning and end of the sample receiving chamber 4 are clearly visible with MRI visualization due to the MRI visualization markers assigned to them, it is now possible for the first time to precisely localize the area within the tissue from which the tissue sample is to be taken.

[0021] As soon as the biopsy needle 2 is correctly positioned, the cutting sleeve 5 surrounding the biopsy needle 2 is displaced at high speed toward the distal end of the biopsy needle by triggering the spring drive located in the handling device 1, so that the cutting edge 6 of the cutting sleeve 5 cuts off the tissue that has penetrated into the sample receiving chamber 4 as a tissue sample from the surrounding tissue, and at the same time the cutting sleeve 5 closes the sample receiving chamber 4. The tissue sample enclosed in the sample receiving chamber 4 can then be removed without coming into contact with the surrounding tissue again along the puncture channel.

[0022] List of reference symbols:

[0023] 1 : Handling device

[0024] 2: Biopsy needle 3: Cutting edge of the biopsy needle

[0025] 4: Sample recording room

[0026] 4a: proximal end surface of the sample receiving chamber

[0027] 4b: distal end surface of the sample receiving chamber

[0028] 5: Cutting sleeve 6: Cutting edge of the cutting sleeve

Claims

Patent claims 1.) Biopsy device for taking tissue samples under MRI visualization, comprising a biopsy needle (2) which is attached to a handling device (1) and can be inserted into the tissue to be examined, said biopsy needle (2) being provided in its distal end region with a laterally open sample receiving space (4) extending in the longitudinal direction thereof, over which a cutting sleeve (5) which closely surrounds the biopsy needle (2) and is provided distally with a cutting edge (6) is displaceable in order to cut off the tissue sample which has penetrated into the sample receiving space (4) of the biopsy needle (2) after the biopsy needle has been inserted into the sample receiving space (4) of the biopsy needle (2) from the surrounding tissue, wherein the device as a whole is made of materials which are suitable for MRI visualization, characterized in that in the sample receiving space (4) of the biopsy needle (2) on the one hand in the region of its distal end and on the other hand in the region of its proximal end, MRI visualization markers are arranged, which MRI visualization markers are applied as if they were applied to the axial end surfaces (4 a,4 b) of the sample receiving space (4) applied polymer layers are formed., 2.) Biopsy device according to claim 1, characterized in that the polymer layers serving as MRI visualization markers are 0.1 mm to 2 mm, preferably 0.2 to 1 mm thick. 3.) Biopsy device according to one of claims 1 or 2, characterized in that the polymer layers serving as MRI visualization markers consist of a cyanoacrylate mixed with MRI markers. 4.) Biopsy device according to one of claims 1 to 3, characterized in that the polymer layers used as MRI visualization markers are filled with particles of MRI contrast agents.

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