JP2020049153A - Medical device - Google Patents

Abstract

To provide a medical device which can increase diffusibility of an administered article injected from a distal end opening while partitioning a plurality of lumens extending in an axial direction.SOLUTION: A medical device is a long medical device for puncturing a biological tissue from a distal end and includes an inner cylindrical part for partitioning an inner lumen extending to a distal end opening and an outer cylindrical part which is positioned in the outside in a radial direction of the inner cylindrical part, partitions an outer lumen by separating from the inner cylindrical part, and has a side wall opening formed on a side wall to communicate the outer lumen. A distal end of the inner cylindrical part is positioned on the distal end side with respect to the side wall opening of the outer cylindrical part, and the inner cylindrical part includes a distal end part which extends to comes close to the side wall of the outer cylindrical part positioned in the outside in the radial direction of the inner cylindrical part on the distal end side with respect to the side wall opening of the outer cylindrical part.SELECTED DRAWING: Figure 4

Description

  The present invention relates to medical devices.

  In recent years, as a treatment for heart failure and the like, it has been studied to administer a plurality of objects to be administered, such as cells and extracellular matrix, to the same place in a living tissue such as the inner wall of the left ventricle of the heart. In such a case, a lumen, which is a hollow portion extending in the axial direction, is defined, and the subject is administered to the living tissue through the lumen using a long medical device that can puncture the living tissue at the tip. It is possible. In order to administer a plurality of types of objects to be administered, it is preferable that a number of lumens corresponding to the number of types of the object to be administered be partitioned in the medical device.

  For example, Patent Literature 1 discloses a medical device having a lumen 430 and an auxiliary lumen 440.

US Patent Application Publication No. 2008/0125745

  However, the medical device disclosed in Patent Literature 1 does not disclose any configuration for improving the diffusibility of an object to be discharged from the lumen at the distal end side of the two lumens.

  An object of the present invention is to provide a medical device capable of partitioning a plurality of lumens extending in the axial direction and increasing the diffusibility of a substance to be discharged from a distal end opening.

  A medical device according to a first aspect of the present invention is a long medical device that is punctured from a distal end into a living tissue, the inner cylindrical portion defining an inner lumen extending to a distal end opening, An outer cylindrical portion positioned radially outside the inner cylindrical portion, defining an outer lumen between the inner cylindrical portion and the inner cylindrical portion, and having a side wall formed with a side wall opening communicating with the outer lumen in the side wall. The tip of the portion is located on the distal end side than the side wall opening of the outer cylinder portion, and the inner cylinder portion is on the distal end side than the side wall opening of the outer cylinder portion, A tip portion extending toward the side wall of the outer cylinder portion located radially outside the inner cylinder portion;

  In the medical device as one embodiment of the present invention, the distal end of the inner cylindrical portion is an enlarged diameter portion whose cross-sectional area gradually increases toward the distal end.

  In the medical device as one embodiment of the present invention, the inner cylindrical portion is coupled to the side wall of the outer cylindrical portion at the distal end.

  In the medical device as one embodiment of the present invention, a distal end surface of the outer cylindrical portion is constituted by a blade surface inclined with respect to an axial direction of the inner cylindrical portion.

  In the medical device as one embodiment of the present invention, a plurality of the side wall openings are formed in the outer cylindrical portion.

  In the medical device as one embodiment of the present invention, three or more of the side wall openings of the outer cylindrical portion are formed at different positions in the circumferential direction of the side wall.

  In the medical device as one embodiment of the present invention, a plurality of the side wall openings of the outer cylindrical portion are formed at different positions in the axial direction of the side wall.

  Advantageous Effects of Invention According to the present invention, it is possible to provide a medical device capable of partitioning a plurality of lumens extending in the axial direction and increasing the diffusibility of a substance to be discharged from a distal end opening.

It is a figure showing the medical instrument as one embodiment of the present invention. FIG. 2 is an external perspective view of the medical device shown in FIG. 1. It is a front view of the medical device shown in FIG. FIG. 4 is a sectional view taken along line AA of FIG. 3. FIG. 5 is a sectional view taken along line BB of FIG. 4. FIG. 5 is a cross-sectional view taken along line CC of FIG. 4. 3 is a flowchart illustrating an example of an administration method performed using the medical device of FIG. 1. FIG. 2 is a schematic diagram showing an example of an administration state of cells and extracellular matrix administered using the medical device of FIG. 1.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In each of the drawings, common components are denoted by the same reference numerals.

  FIG. 1 is a diagram showing a medical device 1 as one embodiment of the present invention. As shown in FIG. 1, the medical device 1 is elongate. FIG. 1 shows a state in which the medical device 1 extends from outside the body of the subject to the left ventricle LV of the heart lumen through a cylindrical catheter 100 as another medical device. Specifically, the catheter 100 is inserted into the body of the subject from the femoral artery FA, and extends into the left ventricle LV through the aorta AO and the aortic valve AV. Then, the distal end 8 of the medical device 1 is delivered to the left ventricle LV through the catheter 100 while a portion of the proximal end side of the medical device 1 is located outside the body of the subject. The catheter 100 may be inserted into the body of the subject from, for example, the radial artery of the wrist instead of the femoral artery FA.

  FIG. 2 is an external perspective view of the medical device 1. FIG. 3 is a front view of the medical device 1. FIG. 4 is a sectional view taken along line AA of FIG. FIG. 5 is a sectional view taken along line BB of FIG. FIG. 6 is a sectional view taken along the line CC of FIG. Here, in the present specification, a surface facing the distal end 8 side of the medical device 1 is referred to as a front surface. Hereinafter, the case where the medical device 1 is viewed from the distal end 8 side (see FIG. 3) may be simply referred to as “front view”. The medical device 1 has a needle-like configuration on the distal end 8 side.

  As shown in FIGS. 2 to 6, the medical device 1 includes an outer cylinder 10 and an inner cylinder 20. The outer tube part 10 includes a distal end 8, and can puncture a living tissue such as an inner wall of the left ventricle LV (see FIG. 1) from the distal end 8. The outer tube portion 10 and the inner tube portion 20 extend in a direction along the central axis O (hereinafter, also referred to as “axial direction”).

  The outer cylinder portion 10 has a cylindrical shape with the radius of the outer peripheral surface 11 being R1 and the radius of the inner peripheral surface 12 being R2 with the center axis O as the center. The outer cylinder 10 may have a constant diameter. The inner cylindrical portion 20 includes a cylindrical main body portion 23 having a radius of the outer peripheral surface 21 of R3 and a radius of the inner peripheral surface 22 of R4, and a tip portion 24 located on the distal end 8 side of the main body portion 23. . The body 23 may have a constant diameter. Here, R1> R2> R3> R4 holds. The outer cylinder 10 is located radially outside the inner cylinder 20.

  The inner cylinder part 20 partitions the inner lumen 31. The main body 23 and the distal end 24 are joined at a joint 25. The distal end portion 24 has a distal end 26 at an end opposite to the coupling portion 25, that is, at an end on the distal end 8 side.

  The distal end portion 24 is configured as an enlarged diameter portion that increases in diameter from the coupling portion 25 toward the distal end 26. That is, the cross-sectional area of the distal end portion 24 gradually increases from the coupling portion 25 toward the distal end 26. Therefore, in the distal end portion 24, the cross-sectional area of the distal end 26 is larger than the cross-sectional area of the coupling portion 25 existing on the proximal end side of the distal end 26. Here, the cross-sectional area means a cross-sectional area in a cross section orthogonal to the axial direction.

  The distal end portion 24 of the inner cylindrical portion 20 is joined to the inner peripheral surface 12 of the outer cylindrical portion 10 at a distal end 26. The tips 24 may be joined in any manner, including, for example, welding, fusing and bonding. Therefore, the outer diameter at the distal end 26 has a cross section of the same radius of R2 as the radius of the inner peripheral surface 12 of the outer cylindrical portion 10. Since the distal end portion 24 is coupled to the inner peripheral surface 12 of the outer cylindrical portion 10, the inner lumen 31 extends to the distal opening 14 formed in the distal end surface 13 on the distal end 8 side of the outer cylindrical portion 10. . The inner lumen 31 communicates with the outside at the distal end opening 14.

  The outer tube portion 10 partitions the outer lumen 32 between the outer tube portion 10 and the inner tube portion 20. Specifically, the outer lumen 32 is defined by the inner peripheral surface 12 of the outer cylindrical portion 10 and the outer peripheral surface 21 of the inner cylindrical portion 20.

  The distal end surface 13 of the outer cylindrical portion may be constituted by a blade surface inclined with respect to the axial direction. Since the distal end surface 13 is formed of a blade surface that is inclined with respect to the axial direction, the puncture resistance between the medical device 1 and the living tissue when the medical device 1 is punctured into the living tissue can be reduced. .

  A side wall opening 15 is formed in a side wall of the outer cylindrical portion 10. The side wall opening 15 allows the outer lumen 32 to communicate with the outside. More specifically, for example, in a cross section having no side wall opening 15 as shown in FIG. 5, the outer lumen 32 does not communicate with the outside, and in a cross section having the side wall opening 15 as shown in FIG. The lumen 32 communicates with the outside.

  As shown in FIGS. 4 and 6, two side wall openings 15 are formed in the outer cylinder portion 10 according to the present embodiment along the axial direction at the top and bottom of FIGS. 4 and 6, respectively. . However, the number and arrangement of the side wall openings 15 formed in the outer cylindrical portion 10 are not limited to this.

  It is sufficient that at least one side wall opening 15 is provided in the outer cylinder portion 10. If at least one side wall opening 15 is provided, when the fluid is supplied to the outer lumen 32 as described later, the fluid in the outer lumen 32 is supplied to the outside through the one side wall opening 15. You.

  As shown in FIGS. 4 and 6, a plurality of side wall openings 15 may be formed in the outer cylindrical portion 10. When a plurality of side wall openings 15 are formed, the fluid in the outer lumen 32 is more efficiently supplied to the outside.

  The side wall openings 15 of the outer cylinder 10 may be formed at three or more different positions in the circumferential direction of the side wall of the outer cylinder 10. The side wall openings 15 formed at three or more places at different positions in the circumferential direction of the side wall may be formed at equal intervals in the circumferential direction of the side wall. For example, when three side wall openings 15 are formed at different positions in the circumferential direction of the side wall, the three side wall openings 15 are formed by the adjacent side wall openings 15 on the center axis O in a front view of the medical device 1. The angle may be formed at a position where the angle is 120 °. Similarly, for example, when four side wall openings 15 are formed at different positions in the circumferential direction of the side wall, the side wall openings 15 adjacent to each other in the front view of the medical device 1 have the central axis. May be formed at a position where the angle formed is 90 °. As described above, since three or more side wall openings 15 are formed at different positions in the circumferential direction of the side wall of the outer cylindrical portion 10, the fluid supplied from the outer lumen 32 is supplied to a wider range in the circumferential direction. It will be easier. In addition, back pressure (back pressure) due to the distal end opening 14 is easily and effectively prevented. Furthermore, when the side wall openings 15 are formed at equal intervals in the circumferential direction of the side wall, the fluid supplied from the outer lumen 32 is easily supplied evenly in the circumferential direction.

  The side wall opening 15 may be formed in the same direction as the tip end surface 13 formed by a blade surface inclined with respect to the axial direction. In the example shown in FIG. 4, the tip surface 13 formed by the blade surface inclined with respect to the axial direction faces upward. Therefore, in the example shown in FIG. 4, the side wall opening 15 may be formed above the side wall. In this case, as described in detail later, when fluid is supplied to the inner lumen 31 and the outer lumen 32, the fluid flows from the inner lumen 31 and the outer lumen 32 to the outside from the same direction (upward in the example of FIG. 4). Supplied. Therefore, the fluid supplied from the inner lumen 31 and the fluid supplied from the outer lumen 32 easily come into contact with each other. As will be described in detail later, if cells are supplied through the inner lumen 31 and extracellular matrix is supplied through the outer lumen 32, the cells may flow into the inner lumen 31 or leak out of the living body through a puncture mark. It becomes easy to suppress that.

  As shown in FIGS. 4 and 6, a plurality of side wall openings 15 of the outer cylinder portion 10 may be formed at different positions in the axial direction of the side wall of the outer cylinder portion 10. In the example shown in FIGS. 4 and 6, the side wall openings 15 are formed at two different positions in the axial direction of the side wall of the outer cylindrical portion 10, but are formed at different positions in the axial direction of the side wall of the outer cylindrical portion 10. Three or more places may be formed. By forming a plurality of side wall openings 15 at different positions in the axial direction of the side wall of the outer cylindrical portion 10 in this manner, the fluid supplied from the outer lumen 32 can be easily supplied to a wider range in the axial direction. .

  As shown in FIG. 4, the distal end 26 of the distal end portion 24 of the inner cylindrical portion 20 is connected to the outer cylindrical portion 10 on the distal end 8 side with respect to the side wall opening 15. When a plurality of side wall openings 15 are formed at different positions in the axial direction, the tip 26 of the tip portion 24 of the inner cylindrical portion 20 is closer to the distal end 8 than the side wall opening 15 closest to the distal end 8. , And the outer cylinder 10. Thus, the outer lumen 32 can be closed by the distal end portion 24 of the inner cylindrical portion 20 and the inner peripheral surface 12 of the outer cylindrical portion 10, and the inner lumen 31 and the outer lumen 32 can be separated. Accordingly, it is possible to prevent the fluid supplied to the inner lumen 31 and the fluid supplied to the outer lumen 32 from mixing in the medical device 1.

  The coupling portion 25 of the distal end portion 24 may be configured to be located closer to the distal end 8 than the side wall opening 15 in the axial direction of the medical device 1. Since the coupling portion 25 is located closer to the distal end 8 than the side wall opening 15, the tip portion 24 is not provided at a position where the side wall opening 15 is formed in the axial direction of the medical device 1. Therefore, at the position where the side wall opening 15 is formed in the axial direction of the medical device 1, the flow path of the fluid supplied to the outer lumen 32 is not narrowed. This facilitates the efficient supply of the fluid from the outer lumen 32 to the outside through the side wall opening 15.

  The inner lumen 31 and the outer lumen 32 communicate with the outside at the distal end opening 14 and the side wall opening 15, respectively. The inner lumen 31 and the outer lumen 32 can be supplied with fluid as a substance to be administered to the living tissue from the proximal end side. The fluid supplied to the inner lumen 31 and the outer lumen 32 includes, for example, cells, an extracellular matrix having a function of adhering the cells to living tissue, a growth factor such as a fibroblast growth factor (bFGF) preparation, a contrast agent, And one or more of the biocompatible materials.

  The cells as the administration target include, for example, adherent cells (adherent cells). Adherent cells include, for example, adherent somatic cells (eg, cardiomyocytes, fibroblasts, epithelial cells, endothelial cells, hepatocytes, pancreatic cells, kidney cells, adrenal cells, periodontal ligament cells, gingival cells, periosteal cells, skin Cells, synovial cells, chondrocytes, etc.) and stem cells (eg, tissue stem cells such as myoblasts, cardiac stem cells, embryonic stem cells, pluripotent stem cells such as iPS (induced pluripotent stem) cells, mesenchymal stem cells, etc.) And so on. The somatic cells may be those differentiated from stem cells, especially iPS cells. Non-limiting examples of cells as an administration target include, for example, myoblasts (eg, skeletal myoblasts, etc.), mesenchymal stem cells (eg, bone marrow, adipose tissue, peripheral blood, skin, hair root, muscle tissue, Endometrium, placenta, cord blood, etc.), cardiomyocytes, fibroblasts, cardiac stem cells, embryonic stem cells, iPS cells, synovial cells, chondrocytes, epithelial cells (eg, oral mucosal epithelial cells, retinal pigment Epithelial cells, nasal mucosal epithelial cells, etc.), endothelial cells (eg, vascular endothelial cells, etc.), hepatocytes (eg, hepatic parenchymal cells, etc.), pancreatic cells (eg, pancreatic islet cells, etc.), kidney cells, adrenal cells, periodontal ligament Cells, gingival cells, periosteal cells, skin cells and the like.

  The extracellular matrix as a substance to be administered includes, for example, noncellular components present in various tissues and organs such as myocardium, kidney, bladder, and cartilage. The extracellular matrix can be extracted by, for example, homogenizing organs such as myocardium and cartilage. The composition of the extracellular matrix is mainly composed of fibrous proteins, structural proteins, glycosaminoglycans, etc., and includes all types of collagen: fibrils (types I, II, III, V Type (type XI); facit (type IX, XII, XIV); short chain (type VIII, X), basement membrane (type IV), and others (types VI, VII, XIII); Elastin, fibronectin, fibrinogen, fibulin, cadherin, laminin, agrin, entactin, tenascin, link protein, proteoglycan, aggrecan, perlecan, versican, neurocan, brevican, decorin, biglycan, serglycin, syndecan, glypican, lumican, keratincan Proteoglycan sulfate, hyaluronic , Including the chitin and the like. In addition, the proportion of each composition of the extracellular matrix depends on the proportion of the composition constituting the tissue.

  Biocompatible materials as the administration target include, for example, polyacrylamide gel, polyvinylpyrrolidone gel, gelatin gel, β-glucan gel, agarose gel, carboxymethylcellulose gel, ethylene vinyl alcohol, zirconium, hydroxyapatite, polydimethylsiloxane, dextranomer , Silicones, glycols and mixtures thereof, and particles using them, porous particles, fibers, porous fibers, sheets, porous sheets and combinations thereof.

  The material for forming the outer tube portion 10 and the inner tube portion 20 of the medical device 1 preferably has a certain degree of flexibility, and for example, metal or resin can be used. Examples of the metal include a pseudoelastic alloy (including a superelastic alloy) such as a Ni-Ti alloy, and stainless steel (for example, SUS304, SUS303, SUS316, SUS316L, SUS316J1, SUS316J1L, SUS405, SUS430, SUS434, SUS444, SUS429, SUS430F, SUS302, etc.), cobalt-based alloys, noble metals such as gold and platinum, tungsten-based alloys, and carbon-based materials (including piano wires). Examples of the resin include polyolefin (for example, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of them), polyvinyl chloride, polyamide, polyamide Examples thereof include polymer materials such as elastomers, polyesters, polyester elastomers, polyurethanes, polyurethane elastomers, polyimides, and fluororesins, and mixtures thereof, and two or more polymer materials described above. Further, examples of the resin include engineering plastics represented by polyetheretherketone. Further, the outer tube 10 and the inner tube 20 may be formed of a multilayer tube or the like made of a composite formed of these metals and resins.

  FIG. 7 is a flowchart illustrating an example of an administration method performed using the medical device 1. In the present embodiment, a case where cells are supplied from the inner lumen 31 and extracellular matrix is supplied from the outer lumen 32 will be described as an example. As shown in FIG. 7, the administration method performed using the medical device 1 includes a puncture step S1, a first administration step S2, and a second administration step S3.

  In the puncture step S <b> 1, the outer tubular portion 10 defining the inner lumen 31 is punctured from the distal end 8 into a living tissue. Specifically, for example, as shown in FIG. 1, the distal end 8 of the outer cylindrical portion 10 of the medical device 1 delivered to the left ventricle LV through the catheter 100 is made to protrude from the catheter 100 to obtain a living tissue. Puncture the inner wall of the left ventricle LV. The operation of the medical device 1 can be performed by an operator, such as a medical worker, operating a part of the proximal end side of the medical device 1 located outside the body of the subject.

  In the first administration step S2, cells are administered to the living tissue through the inner lumen 31 as a hollow portion of the medical device 1. Specifically, for example, cells are supplied from the proximal end side of the medical device 1 through the inner lumen 31. Then, the cells are administered to the living tissue from the distal end opening 14 via the inner lumen 31.

  In the second administration step S3, after the first administration step S2, the extracellular matrix is administered to the living tissue through the outer lumen 32 as a hollow portion of the medical device 1. Specifically, for example, the extracellular matrix is supplied through the outer lumen 32. Then, the extracellular matrix is administered to the living tissue from the side wall opening 15 via the outer lumen 32.

  As described above, after the cells are administered to the living tissue in the first administration step S2, the extracellular matrix is administered to the living tissue in the second administration step S3, so that the composition is brought into a fluid state at the time of catheter administration. Thereafter, the viscosity of the composition increases due to the environment in the living body of the administration subject, so that leakage of the administered cells or the biologically active substance can be prevented. Therefore, after the medical device 1 is removed from the living body, it is possible to prevent the previously administered cells from leaking due to a heartbeat or the like.

  FIG. 8 is a schematic diagram illustrating an example of a state of administration of cells and extracellular matrix administered using the medical device 1. FIG. 8 is a diagram schematically showing the arrangement of cells and extracellular matrix in living tissue when the distal end 8 is punctured from the upper side to the lower side. When cells are supplied from the inner lumen 31 and extracellular matrix is supplied from the outer lumen 32 in a state where the living tissue is punctured with the distal end 8, as shown in FIG. And then the cells are administered deeper into the living tissue. This is because the side opening 15 of the outer lumen 32 is disposed near the inner wall and the distal opening 14 of the inner lumen 31 is disposed at the back of the living tissue when the distal end 8 is punctured in the living tissue. is there. By administering the cells and the extracellular matrix in this manner, the cells can be easily engrafted to the living tissue.

  As described above, the medical device 1 according to the present embodiment is configured such that the inner cylindrical portion 20 that defines the inner lumen 31 extending to the distal end opening 14 and the outer lumen 32 are defined between the inner cylindrical portion 20 and the side wall opening. 15 having an outer cylindrical portion 10. Further, the inner cylindrical portion 20 extends closer to the side wall of the outer cylindrical portion 10 located radially outside the inner cylindrical portion 20 on the distal end 8 side than the side wall opening 15 of the outer cylindrical portion 10. And a leading end portion 24. With this configuration, according to the medical device 1, it is possible to enhance the diffusibility of the substance to be discharged from the distal end opening 14 while partitioning the plurality of lumens extending in the axial direction.

  In particular, as in the above-described embodiment, when the distal end portion 24 is configured as an enlarged diameter portion whose cross-sectional area gradually increases toward the distal end 8 side, the dose of the subject to be discharged from the distal end opening 14 is reduced. The diffusivity can be further increased.

  In addition, the administration method performed using the medical device 1 is not limited to the method described above. For example, before the first administration step of administering cells, a second administration step of administering an extracellular matrix may be performed. In this case, an environment in which the cells easily survive on the living tissue can be prepared in advance.

  The medical device 1 according to the present embodiment can be manufactured, for example, as follows. First, the outer cylinder 10 and the inner cylinder 20 are formed. Next, a blade surface is formed by cutting off the tip of the outer cylindrical part 10 in a direction inclined with respect to the axial direction. Further, the side wall opening 15 is formed on the side wall of the outer cylindrical portion 10 with a blade or the like having a groove shape whose tip forms the side wall opening 15 in a side view. Then, the inner cylindrical portion 20 is inserted into the outer cylindrical portion 10 and the tip 26 of the inner cylindrical portion 20 is connected to the inner peripheral surface 12 of the outer cylindrical portion 10 by, for example, a method such as welding, fusion, and adhesion. . Thus, the medical device 1 can be manufactured. However, the method described here is merely an example, and may be manufactured by another method.

  In the above embodiment, it has been described that the distal end portion 24 is configured as an enlarged diameter portion whose cross-sectional area gradually increases toward the distal end 8 side. However, the tip portion 24 does not necessarily have to be configured as an enlarged diameter portion. The distal end 24 extends closer to the side wall of the outer cylinder 10 located radially outside the inner cylinder 20 on the distal end 8 side than the side wall opening 15 of the outer cylinder 10. I just need.

  Further, in the above embodiment, the inner cylindrical portion 20 has been described as being coupled to the side wall of the outer cylindrical portion 10 at the distal end 26, but the distal end 26 may not necessarily be coupled to the side wall of the outer cylindrical portion 10. In this case, for example, the outer tube part 10 and the inner tube part 20 may be connected to each other by connecting the outer tube part 10 and the main body 23 using another connecting part.

  In the above embodiment, the cross section of the inner lumen 31 and the outer lumen 32 is described as being circular, but the cross section of the inner lumen 31 and the outer lumen 32 may not be necessarily circular. For example, the cross sections of the inner lumen 31 and the outer lumen 32 may be elliptical, polygonal including rectangular, or the like. Also, the cross sections of the inner lumen 31 and the outer lumen 32 may be formed to be arcuate along the circumferential direction.

  The present invention is not limited to the configurations specified in the above embodiments, and various modifications can be made without departing from the contents described in the claims.

  The present disclosure relates to medical devices.

Reference Signs List 1 medical instrument 8 distal end 10 main body 11, 21 outer peripheral surface 12, 22 inner peripheral surface 13 distal end surface 14 distal opening 15 side wall opening 20 inner cylindrical portion 23 main body portion 24 distal end 25 coupling portion 26 distal end 31 inner lumen 32 outer side Lumen 100 catheter

Claims (7)

A long medical device that is punctured from the distal end into a living tissue,
An inner cylindrical portion that defines an inner lumen extending to the distal end opening,
An outer cylindrical portion located radially outside the inner cylindrical portion, defining an outer lumen between the inner cylindrical portion and the inner cylindrical portion, and having a side wall opening formed in a side wall that communicates with the outer lumen,
With
The tip of the inner cylinder is located closer to the distal end than the side wall opening of the outer cylinder,
The inner cylindrical portion extends closer to the side wall of the outer cylindrical portion located radially outside the inner cylindrical portion on the distal end side than the side wall opening of the outer cylindrical portion. A medical device having a tip.   The medical device according to claim 1, wherein the distal end of the inner cylindrical portion is an enlarged diameter portion whose cross-sectional area gradually increases toward the distal end.   The medical device according to claim 1, wherein the inner cylinder is coupled to the side wall of the outer cylinder at the tip.   The medical device according to any one of claims 1 to 3, wherein a distal end surface of the outer cylindrical portion is configured by a blade surface inclined with respect to an axial direction of the inner cylindrical portion.   The medical device according to any one of claims 1 to 4, wherein a plurality of the side wall openings are formed in the outer cylindrical portion.   The medical device according to any one of claims 1 to 5, wherein the side wall openings of the outer cylindrical portion are formed at three or more different positions in a circumferential direction of the side wall.   The medical device according to any one of claims 1 to 6, wherein a plurality of the side wall openings of the outer cylindrical portion are formed at different positions in the axial direction of the side wall.

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