Puncture catheter

Abstract

A puncture catheter (100) has: a medical puncture needle (1) that has a longitudinal direction (x) and has a lumen (1e) extending in the longitudinal direction (x); a first cylindrical member (10) that has a lumen (10e) extending in the longitudinal direction (x) of the puncture needle (1) and that is connected to the puncture needle (1); and a second cylindrical member (20) that is disposed in the lumen (10e) of the first cylindrical member (10), has a lumen (20e) extending in the longitudinal direction (x) of the puncture needle (1) and through which a liquid passes, and is connected to the puncture needle (1). In a cross section perpendicular to the longitudinal direction (x) of the puncture needle (1), the inside diameter of the second cylindrical member (20) in a natural state in a first direction (20x) is larger than the inside diameter of the second cylindrical member (20) in a natural state in a second direction (20y) perpendicular to the first direction (20x).

Description

Puncture catheter

[0001] The present invention relates to a puncture catheter.

[0002] For myocardial tissue having cardiomyocytes that are losing function due to myocardial infarction or the like, treatment is performed to regenerate cardiomyocytes by directly administering a chemical solution such as a cardiomyocyte regeneration cell-containing solution. Thus, when directly administering a chemical solution to an organ in the body, it is necessary to insert a catheter having a needle into the body cavity and puncture the organ with the needle. As a catheter having a needle used in such treatment, for example, the following have been developed.

[0003] Patent Document 1 describes a catheter provided with a fixed piercing element having a spiral structure. This catheter is operated so that the spiral structure of the piercing element is twisted into the heart wall.

[0004] Japanese Patent Application Laid-Open No. 2003-529409

[0005] However, in the catheter described in Patent Document 1, there is a problem that the amount of liquid remaining in the catheter is large, resulting in an increase in the amount of liquid used.

[0006] The present invention has been made in view of the above circumstances, and an object thereof is to provide a puncture catheter that can easily reduce the amount of liquid used.

[0007] The puncture catheter according to an embodiment of the present invention that has solved the above problems is as follows. [1] A medical puncture needle having a longitudinal direction and a lumen extending in the longitudinal direction, a first cylindrical member having a lumen extending in the longitudinal direction and connected to the puncture needle, and a second cylindrical member disposed in the lumen of the first cylindrical member, having a lumen extending in the longitudinal direction through which a liquid passes and connected to the puncture needle, and in a cross section perpendicular to the longitudinal direction, a puncture catheter in which the inner diameter of the second cylindrical member in a natural state in a first direction is larger than the inner diameter of the second cylindrical member in a natural state in a second direction that is a direction perpendicular to the first direction.

[0008] In a cross-section perpendicular to the longitudinal direction of the puncture needle, the inner diameter of the second cylindrical member in its natural state in the first direction is larger than the inner diameter of the second cylindrical member in its natural state in the second direction, which is perpendicular to the first direction. As a result, when liquid passes through, the inner diameter of the second cylindrical member 20 in the first direction becomes smaller than the inner diameter of the second cylindrical member in the first direction in its natural state, and the inner diameter of the second cylindrical member in the second direction becomes larger than the inner diameter of the second cylindrical member in the second direction in its natural state. After the liquid has passed through, it returns to its natural state. That is, after the liquid has passed through, the inner diameters of the second cylindrical member in the first direction and the inner diameters of the second cylindrical member in the second direction return to their original sizes. This makes it easier for the liquid to be pushed distally from the lumen of the second cylindrical member, and the amount of liquid remaining in the lumen of the second cylindrical member can be reduced, thus making it easier to reduce the amount of liquid used.

[0009] The puncture catheter according to the embodiment of the present invention is preferably any of the following [2] to [7]. [2] The puncture catheter according to claim [1], wherein in a cross section perpendicular to the longitudinal direction, the inner diameter of the second cylindrical member in its natural state in the second direction is 1 / 2 or less of the inner diameter of the second cylindrical member in its natural state in the first direction. [3] The puncture catheter according to claim [1] or [2], wherein the average of the inner diameters of the second cylindrical member in its natural state in the second direction, calculated at the distal portion of the second cylindrical member, is greater than the average of the inner diameters of the second cylindrical member in its natural state in the second direction, calculated at the proximal portion of the second cylindrical member. [4] The puncture catheter according to any one of claims [1] to [3], wherein the second cylindrical member has a section in which the inner diameter of the second cylindrical member in its natural state in the second direction becomes shorter towards the proximal side. [5] The puncture catheter according to any one of claims [1] to [4], wherein the proximal portion of the second cylindrical member is made of a material with higher rigidity than the distal portion of the second cylindrical member. [6] The puncture catheter according to any one of [1] to [5], wherein the second tubular member has a section that is thicker towards the proximal side.

[0010] In a cross-section perpendicular to the longitudinal direction of the puncture needle, the inner diameter of the second cylindrical member in its natural state in the first direction is larger than the inner diameter of the second cylindrical member in its natural state in the second direction, which is perpendicular to the first direction. As a result, when liquid passes through, the inner diameter of the second cylindrical member 20 in the first direction becomes smaller than the inner diameter of the second cylindrical member in the first direction in its natural state, and the inner diameter of the second cylindrical member in the second direction becomes larger than the inner diameter of the second cylindrical member in the second direction in its natural state. After the liquid has passed through, it returns to its natural state. That is, after the liquid has passed through, the inner diameters of the second cylindrical member in the first direction and the inner diameters of the second cylindrical member in the second direction return to their original sizes. This makes it easier for the liquid to be pushed distally from the lumen of the second cylindrical member, and the amount of liquid remaining in the lumen of the second cylindrical member can be reduced, thus making it easier to reduce the amount of liquid used.

[0011] Figure 1 shows a side view of a puncture catheter according to an embodiment of the present invention. Figure 2 shows a cross-sectional view of the puncture catheter shown in Figure 1. Figure 3 shows a cross-sectional view of the puncture catheter shown in Figure 2 along the line III-III. Figure 4 shows a side view of a puncture catheter according to an embodiment of the present invention. Figure 5 shows a cross-sectional view of the puncture catheter shown in Figure 4. Figure 6 shows a cross-sectional view of the puncture catheter shown in Figure 5 along the line VI-VI. Figure 7 shows a cross-sectional view showing a modified example of the puncture catheter shown in Figure 5.

[0012] One embodiment of the puncture catheter of the present invention comprises a medical puncture needle having a longitudinal direction and a lumen extending in the longitudinal direction; a first cylindrical member having a lumen extending in the longitudinal direction of the puncture needle and connected to the puncture needle; and a second cylindrical member disposed in the lumen of the first cylindrical member, having a lumen extending in the longitudinal direction of the puncture needle and through which liquid passes, and connected to the puncture needle, wherein, in a cross section perpendicular to the longitudinal direction of the puncture needle, the inner diameter of the second cylindrical member in its natural state in the first direction is larger than the inner diameter of the second cylindrical member in its natural state in the second direction which is perpendicular to the first direction.

[0013] The present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the illustrated examples, and it is possible to implement it with appropriate modifications within the scope that is consistent with the spirit described above and below, and all such modifications are included within the technical scope of the present invention. In each drawing, hatching and reference numerals may be omitted for convenience, in which case refer to the specification or other drawings. Also, the dimensions of various parts in the drawings may differ from the actual dimensions, as priority is given to helping to understand the features of the present invention.

[0014] Referring to Figures 1 to 7, the overall configuration of the puncture catheter according to an embodiment of the present invention will be described. Figures 1 and 4 show side views of the puncture catheter according to an embodiment of the present invention. Figure 2 shows a cross-sectional view of the puncture catheter shown in Figure 1. More specifically, it shows a cross section passing through the central axis of the first cylindrical member and parallel to the longitudinal direction of the first cylindrical member. Figure 3 shows a cross-sectional view of the puncture catheter shown in Figure 2 along the line III-III. Figure 5 shows a cross-sectional view of the puncture catheter shown in Figure 4. More specifically, it shows a cross section passing through the central axis of the first cylindrical member and parallel to the longitudinal direction of the first cylindrical member. Figure 6 shows a cross-sectional view of the puncture catheter shown in Figure 5 along the line VI-VI. Figure 7 shows a cross-sectional view showing a modified example of the puncture catheter shown in Figure 5. Figures 1 to 7 show a puncture catheter 100 having a puncture needle 1, a first cylindrical member 10, and a second cylindrical member 20. More specifically, Figures 1 to 7 show the natural state. The term "natural state" refers to a state in which no external force is applied to the puncture catheter 100.

[0015] In this drawing, the longitudinal direction of the puncture needle 1 is indicated by x, the radial direction of the puncture needle 1 by y, and the circumferential direction of the puncture needle 1 by c. The radial direction y is perpendicular to the longitudinal direction x. In other words, the longitudinal direction x of the puncture needle 1 can also be said to be the direction of extension of the puncture needle 1. For ease of understanding, this drawing shows an embodiment in which the longitudinal direction x of the puncture needle 1 coincides with the longitudinal direction of the first cylindrical member 10 and the longitudinal direction of the second cylindrical member 20, the radial direction y of the puncture needle 1 coincides with the radial direction of the first cylindrical member 10 and the radial direction of the second cylindrical member 20, and the circumferential direction c of the puncture needle 1 coincides with the circumferential direction of the first cylindrical member 10 and the circumferential direction of the second cylindrical member 20. However, the present invention is not limited to this embodiment.

[0016] In this specification, the proximal side refers to the direction toward the user's hand relative to the longitudinal direction x of the puncture needle 1, and the distal side refers to the opposite side of the proximal side, i.e., the direction toward the treatment target. Furthermore, when each component is divided into two equal parts along the longitudinal direction x of the puncture needle 1, the portion located on the distal side of each component is called the distal part, and the portion located on the proximal side of each component is called the proximal part. The distal end of each component is the end located furthest distally from each component. The proximal end of each component is the end located furthest proximal from each component. The end of each component refers to the portion including the end of each component and its surroundings. That is, the distal end of each component refers to the portion including the distal end of each component and its surroundings, and the proximal end of each component refers to the portion including the proximal end of each component and its surroundings.

[0017] The puncture catheter 100 includes a puncture needle 1, a first cylindrical member 10, and a second cylindrical member 20.

[0018] The puncture needle 1 is for medical use and is used to puncture target tissue. As shown in Figures 1, 2, 4, 5, and 7, the puncture needle 1 has a longitudinal direction x and a lumen 1e extending in this longitudinal direction x. Through this lumen 1e, liquids such as cell-containing fluid or drug solutions can be delivered to the target tissue.

[0019] As shown in Figures 1 to 7, the first cylindrical member 10 is a cylindrical member having a lumen 10e extending in the longitudinal direction x of the puncture needle 1 and is connected to the puncture needle 1. The first cylindrical member 10 may have a tapered portion at its distal end, the outer diameter of which decreases toward the distal side.

[0020] As shown in Figures 2, 3, and 5-7, the second cylindrical member 20 is a cylindrical member positioned in the lumen 10e of the first cylindrical member 10. The second cylindrical member 20 is connected to the puncture needle 1 and has a lumen 20e extending in the longitudinal direction x of the puncture needle 1. Liquids such as cell-containing fluid or drug solution pass through this lumen 20e.

[0021] As shown in Figures 3 and 6, in a cross-section perpendicular to the longitudinal direction x of the puncture needle 1, the inner diameter of the second cylindrical member 20 in its natural state in the first direction 20x is larger than the inner diameter of the second cylindrical member 20 in its natural state in the second direction 20y, which is perpendicular to the first direction 20x. In the longitudinal direction x of the puncture needle 1, it is sufficient that at least a portion of the second cylindrical member 20 satisfies the above configuration. In the longitudinal direction x of the puncture needle 1, only a portion of the second cylindrical member 20 may satisfy the above configuration. In the longitudinal direction x of the puncture needle 1, the entire second cylindrical member 20 may satisfy the above configuration.

[0022] For example, a second cylindrical member 20 having the above configuration may be manufactured by pressing a cylindrical member in its radial direction. Alternatively, a second cylindrical member 20 having the above configuration may be manufactured by extrusion molding such that the inner diameter in the first direction 20x is larger than the inner diameter in the second direction 20y.

[0023] In a cross-section perpendicular to the longitudinal direction x of the puncture needle 1, the second cylindrical member 20 has a line segment that has the longest length among the line segments connecting the outer edges of the second cylindrical member 20. It is preferable that the direction of extension of this line segment that has the longest length among the line segments connecting the outer edges of the second cylindrical member 20 is the same as the first direction 20x. It is preferable that the second direction 20y is perpendicular to the direction of extension of the line segment that has the longest length among the line segments connecting the outer edges of the second cylindrical member 20.

[0024] In a cross-section perpendicular to the longitudinal direction x of the puncture needle 1, the inner diameter of the second cylindrical member 20 in its natural state in the first direction 20x is larger than the inner diameter of the second cylindrical member 20 in its natural state in the second direction 20y, which is perpendicular to the first direction 20x. As a result, when liquid passes through, the inner diameter of the second cylindrical member 20 in the first direction 20x becomes smaller than the inner diameter of the second cylindrical member 20 in its natural state in the first direction 20x, and the inner diameter of the second cylindrical member 20 in the second direction 20y becomes larger than the inner diameter of the second cylindrical member 20 in its natural state in the second direction 20y. After the liquid passes through, it returns to its natural state. That is, after the liquid passes through, the inner diameters of the second cylindrical member 20 in the first direction 20x and the inner diameters of the second cylindrical member 20 in the second direction 20y return to their original sizes. This makes it easier for the liquid to be pushed distally out of the lumen 20e of the second cylindrical member 20, and reduces the amount of liquid remaining in the lumen 20e of the second cylindrical member 20, thus making it easier to reduce the amount of liquid used.

[0025] The puncture catheter 100 is used to administer liquids such as cell-containing solutions or drug solutions to target tissues. Specifically, the puncture catheter 100 is preferably used for direct administration to internal organs, such as the heart, kidneys, or liver. The liquid administered using the puncture catheter 100 is preferably a cell-containing solution. For example, the puncture catheter 100 can be used to directly administer iPS cell-containing solutions to the liver or kidneys, or to directly administer myocardial regeneration cell-containing solutions to the heart, or more specifically, the myocardium.

[0026] The puncture needle 1 is preferably designed to puncture internal organs. Internal organs refer to organs located inside the body, particularly in the abdomen and chest, and are also known as viscera.

[0027] The puncture needle 1 can be made of, for example, metal or resin. The puncture needle 1 may be made entirely of metal, or entirely of resin. The puncture needle 1 may be made partly of metal and the other part of resin.

[0028] The puncture needle 1 is preferably made of metal only. Examples of metals that make up the puncture needle 1 include stainless steel such as SUS304 and SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, gold, Ni-Ti alloy, Co-Cr alloy, or combinations thereof.

[0029] Examples of resins that make up the puncture needle 1 include polyether ether ketone (PEEK) and polycarbonate (PC). By constructing the puncture needle 1 using only resin and no metal, the puncture needle 1 can be used even for patients with metal allergies.

[0030] The puncture needle 1 may have a distal end 1a and a proximal end 1b. The puncture needle 1 may have an inner surface 1c facing the lumen 1e of the puncture needle 1 and an outer surface 1d facing the outside of the puncture needle 1.

[0031] The length of the puncture needle 1 in the longitudinal direction x can be 2 mm or more, 3 mm or more, 4 mm or more, etc. The length of the puncture needle 1 in the longitudinal direction x can be 50 mm or less, 30 mm or less, 10 mm or less, etc. The length of the puncture needle 1 in the longitudinal direction x refers to the longest length of the puncture needle 1 in the longitudinal direction x. When used as a puncture catheter for puncturing the myocardium, the length of the puncture needle 1 in the longitudinal direction x is preferably 5 mm.

[0032] The length of the puncture needle 1 in the radial direction y can be 0.2 mm or more, 0.3 mm or more, 0.4 mm or more, etc. The length of the puncture needle 1 in the radial direction y can be 10 mm or less, 5 mm or less, 1 mm or less, etc. The length of the puncture needle 1 in the radial direction y refers to the longest length of the puncture needle 1 in the radial direction y. When used as a puncture catheter for puncturing the myocardium, the length of the puncture needle 1 in the radial direction y is preferably 0.45 mm.

[0033] As shown in Figures 4, 5, and 7, the puncture needle 1 may have a cylindrical member 2 and a spiral member 3.

[0034] The tubular member 2 is a tubular member and may have a lumen 2e extending in the longitudinal direction x of the puncture needle 1. This lumen 2e corresponds to the lumen 1e of the puncture needle 1. Through this lumen 2e, liquids such as cell-containing fluid or drug solutions can be delivered to the target tissue. The tubular member 2 may have a distal end 2a and a proximal end 2b.

[0035] The helical member 3 is preferably a member in which a wire 4 is wound in a helical shape. The wire 4 is preferably wound around the cylindrical member 2.

[0036] Regarding the puncture needle 1, by adopting a design in which a spiral member 3 is arranged around a cylindrical member 2, it becomes easier to screw the puncture needle 1 into the target tissue by rotating the puncture needle 1 around the cylindrical member 2 as an axis. This makes it easier to puncture the target tissue with the puncture needle 1. In addition, the wire 4 constituting the spiral member 3 bites into the tissue, making it difficult for the puncture needle 1 to come out of the tissue. Furthermore, the puncture depth can be easily adjusted by adjusting the rotation of the puncture needle 1.

[0037] It is preferable that a hole 5 is formed in the puncture needle 1, connecting the lumen 1e of the puncture needle 1 to the outside of the puncture needle 1. Liquids such as cell-containing fluid or drug solution that have been transported through the lumen 1e are delivered to the target tissue through this hole 5.

[0038] The puncture needle 1 may have only one hole 5 or multiple holes 5. If only one hole 5 is formed on the puncture needle 1, it becomes easier to administer liquids such as cell-containing fluid or drug solutions to a specific point. If multiple holes 5 are formed on the puncture needle 1, it becomes easier to administer liquids such as cell-containing fluid or drug solutions to a wider area.

[0039] When observed from a direction perpendicular to the longitudinal direction x of the puncture needle 1, the outer shape of the hole 5 can be a polygon such as a triangle, square, or pentagon, or a circle, an ellipse, or a combination thereof. Polygons include not only those with clearly defined corner vertices and straight sides, but also rounded polygons with rounded corners, and those with at least some of their sides being curved.

[0040] The first cylindrical member 10 may have a distal end 10a and a proximal end 10b. The first cylindrical member 10 is preferably connected to the proximal end portion of the puncture needle 1. More preferably, the distal end portion of the first cylindrical member 10 is connected to the proximal end portion of the puncture needle 1. Even more preferably, the first cylindrical member 10 is fixed in a state of abutting against the puncture needle 1.

[0041] Preferably, the inner cavity 1e of the puncture needle 1 and the inner cavity 10e of the first cylindrical member 10 are not in communication.

[0042] The first cylindrical member 10 preferably has an inner surface 10c facing the inner cavity 10e of the first cylindrical member 10 and an outer surface 10d facing the outside of the first cylindrical member 10.

[0043] The method of connecting the first cylindrical member 10 and the puncture needle 1 is not particularly limited. Examples include fixing by welding, brazing, adhesion, caulking, etc. Among these, it is preferable that the first cylindrical member 10 and the puncture needle 1 are welded.

[0044] The first cylindrical member 10 may be composed of only one cylindrical member or may be composed of a plurality of cylindrical members.

[0045] The first cylindrical member 10 can be composed of resin, metal, etc. The first cylindrical member 10 may be entirely composed of only metal or may be entirely composed of only resin. The first cylindrical member 10 may have a part composed of metal and other parts composed of resin.

[0046] Examples of the metal constituting the first cylindrical member 10 include stainless steels such as SUS304 and SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, gold, Ni-Ti alloys, Co-Cr alloys, or combinations thereof.

[0047] Examples of the resin constituting the first cylindrical member 10 include synthetic resins such as polyolefin resins (e.g., polyethylene and polypropylene), polyamide resins (e.g., nylon), polyester resins (e.g., PET), aromatic polyether ketone resins (e.g., PEEK), polyether polyamide resins, polyurethane resins, polyimide resins, fluorine resins (e.g., PTFE, PFA, ETFE), or combinations thereof.

[0048] The first cylindrical member 10 preferably includes a portion made of a material containing metal. Only a part of the first cylindrical member 10 may be made of metal, or the entire first cylindrical member 10 may be made of metal.

[0049] As shown in FIGS. 2 to 7, the first cylindrical member 10 preferably has a metal layer 11 made of metal. By having the metal layer 11, it is easier to form the puncture catheter 100 with high torque transmission.

[0050] The metal layer 11 preferably has an inner surface 11c located on the inner side in the radial direction of the first cylindrical member 10 and an outer surface 11d located on the outer side in the radial direction of the first cylindrical member 10.

[0051] The metal layer 11 may be composed of a pipe, a coil around which a wire is wound, a braid in which a wire is woven, a pipe in which holes or grooves are formed, or a combination thereof.

[0052] Preferably, a plurality of grooves 11f are formed in the metal layer 11. The groove 11f may be a bottomed groove or a through groove. Both through grooves and bottomed grooves may be formed in the metal layer 11. By combining through grooves and bottomed grooves or selecting either one, it is easier to obtain a metal layer 11 having desired flexibility and rigidity.

[0053] As shown in Figures 2 and 3, it is preferable that the first cylindrical member 10 has an outer resin layer 12 disposed on the outer surface 11d of the metal layer 11. This makes it less likely for the first cylindrical member 10 to get caught on the body cavity wall, even if holes or grooves 11f are formed in the metal layer 11, and makes it easier to ensure insertion within the body cavity.

[0054] The outer resin layer 12 may be arranged to cover only a portion of the outer surface 11d of the metal layer 11. Alternatively, the outer resin layer 12 may be arranged to cover the entire outer surface 11d of the metal layer 11.

[0055] As shown in Figures 5 to 7, the first cylindrical member 10 may have an inner resin layer 13 arranged on the inner surface 11c of the metal layer 11.

[0056] The inner resin layer 13 may be arranged to cover only a portion of the inner surface 11c of the metal layer 11. Alternatively, the inner resin layer 13 may be arranged to cover the entire inner surface 11c of the metal layer 11.

[0057] Although not shown in the figures, the first cylindrical member 10 may have both an outer resin layer 12 disposed on the outer surface 11d of the metal layer 11 and an inner resin layer 13 disposed on the inner surface 11c of the metal layer 11.

[0058] The second cylindrical member 20 may have a distal end 20a and a proximal end 20b. Preferably, the second cylindrical member 20 is connected to the proximal end of the puncture needle 1. More preferably, the distal end of the second cylindrical member 20 is connected to the proximal end of the puncture needle 1. It is even more preferable that the second cylindrical member 20 is fixed in contact with the puncture needle 1. Preferably, the position where the second cylindrical member 20 and the puncture needle 1 are in contact and fixed is located proximal to the position where the first cylindrical member 10 and the puncture needle 1 are in contact and fixed.

[0059] It is preferable that the lumen 1e of the puncture needle 1 and the lumen 20e of the second cylindrical member 20 are in communication.

[0060] At the midpoint between the distal end 20a and the proximal end 20b of the second cylindrical member 20, the outer shape of the lumen 20e of the second cylindrical member 20 in its natural state, in a cross section perpendicular to the longitudinal direction x of the puncture needle 1, is preferably non-circular, and more specifically, preferably elliptical. At the distal end 20a and the proximal end 20b of the second cylindrical member 20, the outer shape of the lumen 20e of the second cylindrical member 20 in its natural state, in a cross section perpendicular to the longitudinal direction x of the puncture needle 1, is preferably circular.

[0061] Preferably, the second cylindrical member 20 has an inner surface 20c facing the inner lumen 20e of the second cylindrical member 20 and an outer surface 20d facing the outside of the second cylindrical member 20.

[0062] The method of connecting the second cylindrical member 20 and the puncture needle 1 is not particularly limited. Examples include fixing by welding, welding, adhesive, crimping, etc. Among these, it is preferable that the second cylindrical member 20 and the puncture needle 1 are bonded together with an adhesive.

[0063] For example, polyurethane-based, epoxy-based, cyano-based, fluorine-based, and silicone-based adhesives can be used.

[0064] The second cylindrical member 20 may consist of only one cylindrical member, or it may consist of multiple cylindrical members.

[0065] The second cylindrical member 20 can be made of resin, metal, or the like. The second cylindrical member 20 may be made entirely of metal, or entirely of resin. The second cylindrical member 20 may be made partly of metal and the other part of resin.

[0066] Examples of metals that make up the second cylindrical member 20 include stainless steel such as SUS304 and SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, gold, Ni-Ti alloy, Co-Cr alloy, or combinations thereof.

[0067] Examples of resins constituting the second cylindrical member 20 include synthetic resins such as polyolefin resins (e.g., polyethylene and polypropylene), polyamide resins (e.g., nylon), polyester resins (e.g., PET), aromatic polyetherketone resins (e.g., PEEK), polyetherpolyamide resins, polyurethane resins, polyimide resins, and fluororesins (e.g., PTFE, PFA, ETFE), or combinations thereof.

[0068] The second cylindrical member 20 preferably includes a portion made of a resin-containing material. Only a portion of the second cylindrical member 20 may be made of resin, or the entire second cylindrical member 20 may be made of resin. The second cylindrical member 20 is preferably made of an elastically deformable material.

[0069] In a cross-section perpendicular to the longitudinal direction x of the puncture needle 1, the inner diameter of the second cylindrical member 20 in its natural state in the second direction 20y is preferably 1 / 2 or less, more preferably 1 / 3 or less, and even more preferably 1 / 4 or less, of the inner diameter of the second cylindrical member 20 in its natural state in the first direction 20x. This makes it easier for liquid to be pushed distally from the lumen 20e of the second cylindrical member 20, and the amount of liquid remaining in the lumen 20e of the second cylindrical member 20 can be reduced, making it easier to reduce the amount of liquid used. In a cross-section perpendicular to the longitudinal direction x of the puncture needle 1, the inner diameter of the second cylindrical member 20 in its natural state in the second direction 20y can be 1 / 30 or more, 1 / 20 or 1 / 10 or more, of the inner diameter of the second cylindrical member 20 in its natural state in the first direction 20x.

[0070] As shown in Figure 5, the average of the natural inner diameter of the second cylindrical member 20 in the second direction 20y, calculated at the distal portion of the second cylindrical member 20, may be larger than the average of the natural inner diameter of the second cylindrical member 20 in the second direction 20y, calculated at the proximal portion of the second cylindrical member 20. This makes it easier for liquid to be pushed out distally from the lumen 20e of the second cylindrical member 20, reducing the amount of liquid remaining in the lumen 20e of the second cylindrical member 20, thus making it easier to reduce the amount of liquid used. It is also permissible for the average of the natural inner diameter of the second cylindrical member 20 in the second direction 20y, calculated at the distal portion of the second cylindrical member 20, to be smaller than the average of the natural inner diameter of the second cylindrical member 20 in the second direction 20y, calculated at the proximal portion of the second cylindrical member 20.

[0071] As shown in Figure 5, the second cylindrical member 20 may have a section 24 in which the inner diameter of the second cylindrical member 20 in its natural state in the second direction 20y is shortened towards the proximal side. This makes it easier for liquid to be pushed out distally from the lumen 20e of the second cylindrical member 20, and the amount of liquid remaining in the lumen 20e of the second cylindrical member 20 can be reduced, making it easier to reduce the amount of liquid used. The second cylindrical member 20 may have a section in which the inner diameter of the second cylindrical member 20 in its natural state in the second direction 20y is shortened towards the distal side.

[0072] In its natural state, it is preferable that the inner diameter of the second cylindrical member 20 in the second direction 20y is smaller than the inner diameter of the proximal end 1b of the puncture needle 1 in the second direction 20y. This makes it easier for the liquid to be pushed distally from the lumen 20e of the second cylindrical member 20, and thus reduces the amount of liquid remaining in the lumen 20e of the second cylindrical member 20, making it easier to reduce the amount of liquid used.

[0073] In its natural state, the inner diameter of the second cylindrical member 20 in the first direction 20x may be larger than the inner diameter of the proximal end 1b of the puncture needle 1 in the first direction 20x. In its natural state, the inner diameter of the second cylindrical member 20 in the first direction 20x may be smaller than the inner diameter of the proximal end 1b of the puncture needle 1 in the first direction 20x.

[0074] The proximal portion of the second cylindrical member 20 may be made of a material with higher rigidity than the distal portion of the second cylindrical member 20. This makes it easier for the liquid to be pushed out distally from the lumen 20e of the second cylindrical member 20, thereby reducing the amount of liquid remaining in the lumen 20e of the second cylindrical member 20, and thus making it easier to reduce the amount of liquid used. It is also permissible for the distal portion of the second cylindrical member 20 to be made of a material with higher rigidity than the proximal portion of the second cylindrical member 20.

[0075] As shown in Figure 7, the second cylindrical member 20 may have a section 25 that is thicker towards the proximal side. This makes it easier for liquid to be pushed out distally from the lumen 20e of the second cylindrical member 20, and the amount of liquid remaining in the lumen 20e of the second cylindrical member 20 can be reduced, thus making it easier to reduce the amount of liquid used. The second cylindrical member 20 may have a section that is thicker towards the distal side.

[0076] As shown in Figures 2, 5, and 7, it is preferable that the second cylindrical member 20 has a tapered portion 22 in which the outer diameter increases toward the distal end. It is even more preferable that the second cylindrical member 20 has a tapered portion 22 in which the outer diameter increases toward the distal end.

[0077] The length of the first cylindrical member 10 in the longitudinal direction x of the puncture needle 1 and the length of the second cylindrical member 20 in the longitudinal direction x of the puncture needle 1 can be 1100 mm or more, 1330 mm or more, 1560 mm or more, etc. The length of the first cylindrical member 10 in the longitudinal direction x of the puncture needle 1 and the length of the second cylindrical member 20 in the longitudinal direction x of the puncture needle 1 can be 2300 mm or less, 2070 mm or less, 1840 mm or less, etc. The length of the first cylindrical member 10 in the longitudinal direction x of the puncture needle 1 refers to the longest length of the length of the first cylindrical member 10 in the longitudinal direction x of the puncture needle 1. The length of the second cylindrical member 20 in the longitudinal direction x of the puncture needle 1 refers to the longest length of the length of the second cylindrical member 20 in the longitudinal direction x of the puncture needle 1. When used as a puncture catheter for puncturing the myocardium, it is preferable that the length of the first cylindrical member 10 in the longitudinal direction x of the puncture needle 1 and the length of the second cylindrical member 20 in the longitudinal direction x of the puncture needle 1 are 1500 mm. The length of the first cylindrical member 10 in the longitudinal direction x of the puncture needle 1 and the length of the second cylindrical member 20 in the longitudinal direction x of the puncture needle 1 may be the same or different.

[0078] The length of the first cylindrical member 10 in the radial direction y of the puncture needle 1 can be 0.3 mm or more, 0.5 mm or more, 0.8 mm or more, etc. The length of the first cylindrical member 10 in the radial direction y of the puncture needle 1 can be 20.0 mm or less, 15.0 mm or less, 10.0 mm or less, etc. The length of the first cylindrical member 10 in the radial direction y of the puncture needle 1 refers to the longest length of the first cylindrical member 10 in the radial direction y of the puncture needle 1. When used as a puncture catheter for puncturing the myocardium, it is preferable that the length of the first cylindrical member 10 in the radial direction y of the puncture needle 1 be 0.9 mm.

[0079] The length of the second cylindrical member 20 in the radial direction y of the puncture needle 1 can be 0.1 mm or more, 0.2 mm or more, 0.3 mm or more, etc. The length of the second cylindrical member 20 in the radial direction y of the puncture needle 1 can be 15.0 mm or less, 10.0 mm or less, 5.0 mm or less, etc. The length of the second cylindrical member 20 in the radial direction y of the puncture needle 1 refers to the longest length of the second cylindrical member 20 in the radial direction y of the puncture needle 1. When used as a puncture catheter for puncturing the myocardium, the length of the second cylindrical member 20 in the radial direction y of the puncture needle 1 is preferably 0.5 mm.

[0080] As shown in Figures 2, 5, and 7, it is preferable that the second cylindrical member 20 has a tapered portion 23 in which the outer diameter increases towards the proximal side. It is even more preferable that the second cylindrical member 20 has a tapered portion 23 in which the outer diameter increases towards the proximal side at its proximal end.

[0081] The second cylindrical member 20 may have multiple sections with different inner diameters in the longitudinal direction of the second cylindrical member 20. The inner diameter of the second cylindrical member 20 may be constant for a length from the distal end 20a to the proximal end 20b of the second cylindrical member 20.

[0082] As shown in Figures 2, 3, and 5-7, it is preferable that the inner surface 10c of the first cylindrical member 10 and the outer surface 20d of the second cylindrical member 20 are separated. It is preferable that the inner surface 10c of the first cylindrical member 10 and the outer surface 20d of the second cylindrical member 20 are not in contact. This makes it easier for the second cylindrical member 20 to deform within the lumen 10e of the first cylindrical member 10. Therefore, the second cylindrical member 20 becomes more easily deformed by the injection of liquid.

[0083] As shown in Figures 2, 3, and 5-7, it is preferable that a gap exists between the inner surface 10c of the first cylindrical member 10 and the outer surface 20d of the second cylindrical member 20. More preferably, air is present in this gap. This makes it easier for the second cylindrical member 20 to deform within the lumen 10e of the first cylindrical member 10. Therefore, the second cylindrical member 20 becomes more easily deformed by the injection of liquid. From the viewpoint of enhancing this effect, it is preferable that no other members are placed between the inner surface 10c of the first cylindrical member 10 and the outer surface 20d of the second cylindrical member 20.

[0084] As shown in Figures 2, 5, and 7, it is preferable that the first connection portion 31, which is the portion where the first cylindrical member 10 and the puncture needle 1 are connected, is located distal to the distal end of the second connection portion 32, which is the portion where the second cylindrical member 20 and the puncture needle 1 are connected. More specifically, it is preferable that the distal end of the first connection portion 31, which is the portion where the first cylindrical member 10 and the puncture needle 1 are connected, is located distal to the distal end of the second connection portion 32, which is the portion where the second cylindrical member 20 and the puncture needle 1 are connected. It is preferable that the first cylindrical member 10 and the puncture needle 1 are in contact at the first connection portion 31. It is preferable that the second cylindrical member 20 and the puncture needle 1 are in contact at the second connection portion 32.

[0085] The puncture catheter 100 may further have a connecting member 40 having a lumen 40e and connected to the proximal portions of the first cylindrical member 10 and the second cylindrical member 20. The lumen 40e of the connecting member 40 is in communication with the lumen 20e of the second cylindrical member 20, and the tip of a syringe may be inserted into the lumen 40e of the connecting member 40. This makes it easier to inject the liquid in the syringe into the lumen 20e of the second cylindrical member 20. The liquid injected into the lumen 20e of the second cylindrical member 20 may be transported to the target tissue by passing through the lumen 1e and hole 5 of the puncture needle 1.

[0086] As shown in Figures 2, 5, and 7, the proximal end of the third connection portion 33, where the first cylindrical member 10 and the connecting member 40 are connected, may be located more proximal to the proximal end of the fourth connection portion 34, where the second cylindrical member 20 and the connecting member 40 are connected. Although not shown, the proximal end of the third connection portion 33, where the first cylindrical member 10 and the connecting member 40 are connected, may be located more distal to the proximal end of the fourth connection portion 34, where the second cylindrical member 20 and the connecting member 40 are connected. It is preferable that the first cylindrical member 10 and the connecting member 40 are in contact at the third connection portion 33. It is preferable that the second cylindrical member 20 and the connecting member 40 are in contact at the fourth connection portion 34.

[0087] The constituent material of the connecting member 40 is not particularly limited, but for example, polyolefin resins such as polypropylene (PP) and polyethylene (PE), polyester resins such as polyethylene terephthalate (PET), synthetic resins such as polycarbonate resin, ABS resin, and polyurethane resin can be used.

[0088] This application claims the benefit of priority based on Japanese Patent Application No. 2024-231489, filed on 27 December 2024. The entire specification of Japanese Patent Application No. 2024-231489 is incorporated herein by reference.

[0089] 1: Puncture needle 1a: Distal end 1b: Proximal end 1c: Inner surface 1d: Outer surface 1e: Lumen 2: Cylindrical member 2a: Distal end 2b: Proximal end 2e: Lumen 3: Helical member 4: Wire 5: Hole 10: First cylindrical member 10a: Distal end 10b: Proximal end 10c: Inner surface 10d: Outer surface 10e: Lumen 11: Metal layer 11c: Inner surface 11d: Outer surface 11f: Groove 12: Outer resin layer 13: Inner resin layer 20: Second cylindrical member 20x: First direction 20y: Second direction 20a: Distal end 20b: Proximal end 20c: Inner surface 20d: Outer surface 20e: Lumen 22: Tapered section 23: Tapered section 24: Section 25: Section 31: First connection 32: Second connection 33: Third connection 34: Fourth connection 40: Connecting member 40e: Lumen 100: Puncture catheter

Claims

1. A puncture catheter comprising: a medical puncture needle having a longitudinal direction and a lumen extending in the longitudinal direction; a first cylindrical member having a lumen extending in the longitudinal direction and connected to the puncture needle; and a second cylindrical member disposed in the lumen of the first cylindrical member, having a lumen extending in the longitudinal direction through which liquid passes, and connected to the puncture needle, wherein in a cross section perpendicular to the longitudinal direction, the inner diameter of the second cylindrical member in its natural state in the first direction is greater than the inner diameter of the second cylindrical member in its natural state in the second direction which is perpendicular to the first direction.

2. The puncture catheter according to claim 1, wherein, in a cross section perpendicular to the longitudinal direction, the inner diameter of the second cylindrical member in its natural state in the second direction is 1 / 2 or less of the inner diameter of the second cylindrical member in its natural state in the first direction.

3. The puncture catheter according to claim 1 or 2, wherein the average of the inner diameter of the second cylindrical member in its natural state in the second direction, calculated at the distal portion of the second cylindrical member, is greater than the average of the inner diameter of the second cylindrical member in its natural state in the second direction, calculated at the proximal portion of the second cylindrical member.

4. The puncture catheter according to claim 1 or 2, wherein the second cylindrical member has a section in which the inner diameter of the second cylindrical member in its natural state in the second direction becomes shorter toward the proximal side.

5. The puncture catheter according to claim 1 or 2, wherein the proximal portion of the second cylindrical member is made of a material with higher rigidity than the distal portion of the second cylindrical member.

6. The puncture catheter according to claim 1 or 2, wherein the second tubular member has a section that becomes thicker towards the proximal side.

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