catheter

Abstract

To provide a catheter which can effectively hold a guide wire inserted into a lumen and improve sliding properties of the guide wire.SOLUTION: A catheter 1 includes a shaft 2 in which a lumen 5 communicates from a distal end to a proximal end. The shaft 2 has a radiopaque marker 30 at least in one part in an axial direction X of the shaft 2. An inner diameter D1 of a marker arrangement part 51 where the marker 30 is arranged in the shaft 2 is smaller than an inner diameter D2 of a marker absence part 52 where the marker 30 is not arranged in the shaft 2, and the surface roughness of an inner surface of the marker arrangement part 51 is larger than the surface roughness of an inner surface of the marker absence part 52.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a catheter for use in a lumen such as a blood vessel. [Background technology]

[0002] In recent years, intraluminal treatments such as those using catheters for blood vessels have become popular because of the minimal surgical invasiveness involved. For example, catheters that are selectively introduced into complexly branched blood vessels within the body are generally pushed along a guidewire that has been introduced into the blood vessels beforehand, allowing therapeutic drugs, diagnostic contrast agents, and the like to be circulated through the lumen. Furthermore, catheters have radiopaque markers disposed on their shafts so that their positions within the lumen can be recognized from outside the body (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-100321 Summary of the Invention [Problem to be solved by the invention]

[0004] A catheter has a guidewire inserted into its internal lumen and is pushed along the guidewire to the target location in the blood vessel. Therefore, the catheter must be able to slide smoothly along the guidewire. Furthermore, the difference between the inner diameter of the distal end of the catheter and the outer diameter of the guidewire is small, making it easier to support the guidewire. Therefore, it is desirable for the catheter to be able to improve its ability to support and slide along the guidewire.

[0005] The present invention has been made to solve the above-mentioned problems, and aims to provide a catheter that can effectively hold a guide wire inserted into a lumen and improve the slidability of the guide wire. [Means for solving the problem]

[0006] A catheter that achieves the above object is a catheter equipped with a shaft having a lumen that communicates from the distal end to the proximal end, wherein the shaft has a radiopaque marker at least at one location in the axial direction of the shaft, the inner diameter of a marker placement portion of the shaft where the marker is placed is smaller than the inner diameter of a marker-free portion of the shaft where no marker is placed, and the surface roughness of the inner surface of the marker placement portion is greater than the surface roughness of the inner surface of the marker-free portion. Furthermore, half of the difference in inner diameter obtained by subtracting the inner diameter of the marker-disposed portion from the inner diameter of the marker-disposed portion is greater than the thickness of the marker in the radial direction of the shaft. It is characterized by the fact that Another aspect of a catheter that achieves the above-mentioned object is a catheter having a shaft with a lumen that connects from the tip to the base end, wherein the shaft has an X-ray opaque marker at at least one location in the axial direction of the shaft, and a reinforcing body that is arranged between the outer surface and inner surface of the shaft and comprises a plurality of wires braided into a tubular shape, wherein the inner diameter of the marker placement section of the shaft where the marker is placed is smaller than the inner diameter of the marker-absent section of the shaft where the marker is not placed, the surface roughness of the inner surface of the marker placement section is greater than the surface roughness of the inner surface of the marker-absent section, half of the difference in inner diameter obtained by subtracting the inner diameter of the marker placement section from the inner diameter of the marker-absent section is smaller than the thickness of the marker in the radial direction of the shaft, and at least a portion of the reinforcing body is arranged between the marker and the outer surface of the shaft. Yet another aspect of a catheter that achieves the above-mentioned object is a catheter having a shaft with a lumen that connects from the tip to the base end, wherein the shaft has an X-ray opaque marker at at least one location in the axial direction of the shaft, the inner diameter of the marker placement section of the shaft where the marker is placed is smaller than the inner diameter of the marker-absent section of the shaft where no marker is placed, the surface roughness of the inner surface of the marker placement section is greater than the surface roughness of the inner surface of the marker-absent section, half of the difference in inner diameter obtained by subtracting the inner diameter of the marker placement section from the inner diameter of the marker-absent section is smaller than the thickness of the marker in the radial direction of the shaft, the marker placement sections have one tip marker placement section that is closest to the tip end and at least one base end marker placement section that is closer to the base end than the marker placement section, and the inner diameter of the tip marker placement section is smaller than the inner diameter of the base end marker placement section. Yet another aspect of a catheter that achieves the above-mentioned object is a catheter having a shaft with a lumen that communicates from the tip to the base end, wherein the shaft has an X-ray opaque marker at at least one location along the axial direction of the shaft, the marker placement section of the shaft where the marker is placed has a constant inner diameter section with a constant inner diameter along the axial direction, the inner diameter of the constant inner diameter section is smaller than the inner diameter of a marker-absent section of the shaft where no marker is placed, and the surface roughness of the inner surface of the constant inner diameter section of the marker placement section is greater than the surface roughness of the inner surface of the marker-absent section. [Effects of the Invention]

[0007] The catheter configured as described above can effectively hold a guidewire inserted into the lumen by virtue of the small inner diameter of the marker placement section. Furthermore, because the inner diameter of the marker-free section is larger than that of the marker placement section, the sliding resistance of the catheter as a whole with the guidewire can be reduced. Furthermore, because the surface roughness of the inner surface of the marker placement section, which has a smaller inner diameter and is therefore more likely to come into contact with the guidewire than the marker-free section, is greater than the surface roughness of the inner surface of the marker-free section, the sliding resistance of the catheter as a whole with the guidewire can be reduced. Therefore, this catheter can effectively hold a guidewire inserted into the lumen and improve the slidability of the guidewire.

[0008] Half of the difference in inner diameter, obtained by subtracting the inner diameter of the marker-placed portion from the inner diameter of the marker-absent portion, may be greater than the thickness of the marker in the radial direction of the shaft. This allows the marker to be embedded smoothly inside the shaft, thereby preventing a decrease in shaft strength due to the placement of the marker.

[0009] Half the difference in inner diameter, obtained by subtracting the inner diameter of the marker placement section from the inner diameter of the marker-free section, may be smaller than the thickness of the marker in the radial direction of the shaft. This prevents the wall thickness of the marker placement section from becoming unnecessarily thick due to the placement of a marker. It also prevents the outer surface of the marker placement section from protruding radially outward. This prevents a decrease in the ease of inserting the catheter into a biological lumen.

[0010] The catheter may have a reinforcing member disposed between the outer and inner surfaces of the shaft and including a plurality of braided wires in a tubular shape, and at least a portion of the reinforcing member may be disposed between the marker and the outer surface of the shaft, thereby effectively preventing the marker from falling off the shaft.

[0011] The marker placement section may have one distal marker placement section closest to the distal end and at least one proximal marker placement section closer to the proximal end than the marker placement section, and the inner diameter of the distal marker placement section may be smaller than the inner diameter of the proximal marker placement section. This allows the catheter to be equipped with multiple markers, while effectively improving the retention of the guidewire with the distal marker placement section and effectively improving the slidability of the guidewire with the proximal marker placement section.

[0012] Another aspect of a catheter that achieves the above-mentioned object is a catheter having a shaft with a lumen that connects from the tip to the base end, wherein the shaft has a reinforcing member comprising a plurality of wires braided into a tubular shape and arranged in at least a portion between the inner surface of the shaft that forms the lumen and the outer surface of the shaft, and at least one or more radiopaque markers arranged between the reinforcing member and the outer surface, wherein the inner diameter of the marker-arranged portion of the shaft where the marker is arranged is smaller than the inner diameter of the marker-absent portion of the shaft where the marker is not arranged, the difference between the inner diameter of the shaft at the portion adjacent to the marker in the axial direction of the shaft and the inner diameter of the shaft at the portion where the marker is arranged is defined as the inner diameter difference, and half of the inner diameter difference obtained by subtracting the inner diameter of the marker-arranged portion from the inner diameter of the marker-absent portion is greater than the thickness of the marker in the radial direction of the shaft.

[0013] In another aspect of the catheter configured as described above, the inner diameter of the marker placement section is smaller than the reduction in the inner diameter of the marker-free section due to the presence of a marker, thereby improving the retention of the guidewire inserted into the lumen. Also, because the inner diameter of the marker-free section is larger than the inner diameter of the marker placement section, the sliding resistance of the catheter as a whole with the guidewire can be reduced. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a plan view showing a catheter according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing the tip of the catheter according to the embodiment. [Figure 3] FIG. 2 is an enlarged cross-sectional view showing the distal end of the catheter according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. For convenience of explanation, the dimensions in the drawings may be exaggerated and may differ from the actual dimensions. Furthermore, in this specification and the drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant explanations will be omitted. In this specification, the side of a catheter that is inserted into a biological lumen will be referred to as the "distal side," and the side that is operated will be referred to as the "proximal side."

[0016] The catheter 1 according to this embodiment is introduced into a blood vessel through the radial artery in the arm, the femoral artery in the leg, or a peripheral artery in the lower limb, and is then inserted into an artery in the lower limb for treatment, diagnosis, and the like. The catheter 1 is, for example, a support catheter, but may also be a device for other purposes. The artery in the lower limb refers to an artery near the aortoiliac artery bifurcation and more peripherally. As shown in FIG. 1 , the catheter 1 has a long shaft 2, a hub 3 connected to the base end of the shaft 2, and a kink-resistant protector 4 provided at the connection between the shaft 2 and the hub 3.

[0017] As shown in Figures 1 to 3, the shaft 2 is a flexible tubular member, and has a lumen 5 formed therein from the base end to the tip. A guidewire is inserted through the lumen 5 when the catheter 1 is inserted into a blood vessel. The lumen 5 can also be used as a passage for a medicinal solution, an embolic substance, a contrast medium, a medical instrument, etc.

[0018] The effective length of the shaft 2 is not particularly limited, but is preferably 200 mm to 2600 mm, more preferably 400 mm to 2300 mm, even more preferably 600 mm to 2300 mm, and in this embodiment, it is 900 mm. This enables the catheter 1 to reach the arteries of the lower limbs. The effective length of the shaft 2 is the length of the portion that can be inserted into a blood vessel, a sheath, or the like. In this embodiment, the effective length is the length from the most distal end of the anti-kink protector 4 to the most distal end of the shaft 2. The effective length of the shaft 2 is preferably 1200 mm or more when introduced from an artery in the arm, 650 mm or more when introduced from the femoral artery, and 300 mm or more when introduced from the distal portion of the dorsalis pedis artery or the posterior tibial artery. That's fine too.

[0019] The shaft 2 is composed of multiple layers, including an inner layer 10 that forms the inner surface 11 of the lumen 5, multiple markers 30 arranged radially outward from the inner layer 10, a reinforcing body 20 arranged radially outward from the inner layer 10 and the markers 30, and an outer layer 40 formed radially outward from the inner layer 10, the markers 30, and the reinforcing body 20. The radially outward side refers to the side away from the axial center of the shaft 2.

[0020] The inner diameter of the inner layer 10 is not particularly limited, but is preferably 0.2 mm to 1.2 mm, more preferably 0.4 mm to 1.1 mm, and even more preferably 0.4 mm to 0.55 mm. The inner and outer diameters of the inner layer 10 at the position covered by the marker 30 are smaller than those of the portion adjacent to the axial direction X of the shaft 2. In the embodied product, the inner diameter of the marker-free portion 52 at the base was 0.5 mm, and the inner diameter of the marker-placed portion 51 was 0.42 mm.

[0021] The inner layer 10 has a lumen 5 formed therein. The material constituting the inner layer 10 can be a thermoplastic resin, a thermosetting resin, or the like, and is preferably a fluorine-based resin such as polytetrafluoroethylene (PTFE), or a low-friction material such as high-density polyethylene (HDPE), but may also be a polyamide resin, a polyamide elastomer, polyester, or a polyester elastomer.

[0022] The markers 30 are radiopaque (radiographically opaque) members arranged radially outward from the inner layer 10. The markers 30 include a distal marker 31 located at the most distal end in the axial direction X and multiple base markers 32 located proximal to the distal marker 31. The distal marker 31 and the multiple base markers 32 are spaced apart a predetermined distance in the axial direction X. Each of the distal marker 31 and the base markers 32 is formed by winding a wire made of a radiopaque material into a coil, but the shape is not limited thereto. For example, each marker 30 may have a C-shaped cross section perpendicular to the axial direction X and may be a member that is fitted over the inner layer 10 and then crimped into a tubular shape. Alternatively, each marker 30 may be a coiled round or ribbon-shaped radiopaque metal wire, or a pipe. The number of base markers 32 is preferably two or three, but may be four or more. It should be noted that there may be only one base marker 32, or no base marker 32 may be provided.

[0023] The thickness T of the marker 30 is not particularly limited, but is preferably 0.02 mm to 0.1 mm, more preferably 0.03 mm to 0.08 mm, even more preferably 0.03 mm to 0.04 mm, and is 0.03 mm in this embodiment.

[0024] The axial length of the marker 30 is not particularly limited, but is preferably 0.5 mm to 5 mm, more preferably 0.7 mm to 3 mm, and even more preferably 0.9 mm to 2 mm. In this embodiment, it is 1 mm, but the lengths of the tip marker 31 and the base marker 32 may be different, for example.

[0025] The material constituting the marker 30 can be suitably a metal powder of platinum, gold, silver, tungsten, iridium or an alloy thereof, or a material kneaded with an X-ray contrast agent such as barium sulfate, bismuth oxide, or a coupling compound thereof, or it can also be a metal coil or a solder with contrast properties.

[0026] The reinforcing member 20 is formed by braiding a plurality of wires 21 into a tubular shape with gaps between them around the inner layer 10 and the marker 30. The reinforcing member 20 may be wound with the wires 21 wound horizontally in the same direction, or with different winding directions, such as clockwise or counterclockwise. The winding pitch, inter-lattice distance, and angle of inclination relative to the circumferential direction may be changed depending on the position, and the configuration is not particularly limited. For example, a single wire 21 may be wound in one direction like a coil.

[0027] The reinforcement body 20 may be disposed over the entire axial direction X of the shaft 2, or may be disposed over only a portion of the shaft. In this embodiment, the tip of the reinforcement body 20 is disposed between the tip marker 31 and the base marker 32 on the base end side of the tip marker 31. The base end of the reinforcement body 20 is disposed near the base end of the shaft 2, slightly distal to the base end of the shaft 2. Therefore, the reinforcement body 20 does not cover the outer periphery of the tip marker 31, but does cover the outer periphery of the multiple base markers 32. The portion of the tip of the shaft 2 where the reinforcement body 20 is not disposed has high flexibility, making it easy to change the bending direction along the guidewire and reducing the burden on the contacting biological tissue.

[0028] The wire diameter (diameter) of the wire 21 of the reinforcing member 20 is not particularly limited, but is preferably 0.03 mm to 0.08 mm, more preferably 0.03 mm to 0.06 mm, and even more preferably 0.04 mm to 0.06 mm, and is 0.03 mm in this embodiment.

[0029] The wires 21 used in the reinforcing member 20 can be metal wires such as stainless steel, platinum (Pt), tungsten (W), etc., resin fibers, carbon fibers, glass fibers, etc. Alternatively, a plurality of these wires 21 can be used in combination, and they can be round, oval, or flat wires. Each wire 21 can be used as a single wire for braiding, or two or more wires 21 bundled together as shown in Figure 3 can be used as a single wire for braiding.

[0030] The outer layer 40 is a tubular body disposed around the inner layer 10, the marker 30, and the reinforcing body 20. The outer diameter of the outer layer 40 is not particularly limited, but is preferably 0.6 mm to 1.6 mm, more preferably 0.65 mm to 1.4 mm, and even more preferably 0.65 mm to 0.9 mm. In this embodiment, the outer diameter is 0.75 mm on the tip side of the outer layer 40 and 0.75 mm on the base side of the outer layer 40.

[0031] Examples of materials that can be used for the outer layer 40 include polymeric materials such as polyolefins (e.g., polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ionomers, and mixtures of two or more thereof), polyvinyl chloride, polyamide, polyester elastomers, polyamide elastomers, polyurethane, polyurethane elastomers, polyimides, and fluororesins, as well as thermoplastic resins such as mixtures of these, and thermosetting resins such as epoxy resins. The outer layer 40 may be mixed with a radiopaque material, and the outer layer 40 may be made of the same material as the inner layer 10.

[0032] The shaft 2 has, in the axial direction X, a plurality of marker placement sections 51 where the markers 30 are placed, and a plurality of marker absence sections 52 where the markers 30 are not placed. The marker placement sections 51 and the marker absence sections 52 are alternately arranged in the axial direction X.

[0033] The inner diameter of each marker placement section 51 is smaller than the inner diameter of the marker-absent section 52. This prevents the placement of the markers 30 from making the inner layer 10 or the outer layer 40 unnecessarily thin, thereby reducing the strength of the shaft 2. The inner diameter of the distal marker placement section 53, in which the distal marker 31 is placed, is smaller than the inner diameter of the base marker placement section 54, in which the base marker 32 is placed. This reduces the difference between the inner diameter of the distal end of the shaft 2, where the distal marker placement section 53 is provided, and the outer diameter of the guidewire passing through the lumen 5, thereby enabling the guidewire to be effectively held. The surface roughness of the inner surface of each marker placement section 51 is larger than the surface roughness of the inner surface of the marker-absent section 52. This results in a smaller contact area of ​​a contact object with the inner surface of the marker placement section 51 than with the inner surface of the marker-absent section 52. This results in a smaller frictional resistance of the inner surface of the marker placement section 51 than with the inner surface of the marker-absent section 52. Therefore, the slidability of the contact object against the inner surface of the marker placement section 51 is improved.

[0034] The method for measuring surface roughness is defined by JIS B0601:2001 (ISO 4287:1997). For example, the surface roughness can be the maximum peak height Rp in the reference length, the maximum valley depth Rv in the reference length, or the maximum height Rz, which is the sum of the maximum peak height Rp and the maximum valley depth Rv in the reference length. However, the measurement method is not particularly limited as long as the surface roughness of the inner surface of the marker placement portion 51 is greater than the surface roughness of the inner surface of the marker absence portion 52.

[0035] Each marker placement section 51 has, on its inner circumferential surface, a constant inner diameter section 55 having a substantially constant inner diameter D1, a distal tapered section 56 having an inner diameter that decreases from the constant inner diameter section 55 toward the distal end, and a proximal tapered section 57 having an inner diameter that decreases from the constant inner diameter section 55 toward the proximal end. By having the distal tapered section 56 and the proximal tapered section 57, each marker placement section 51 can prevent the guidewire passing through the lumen 5 from getting caught on the marker placement section 51. The length L of the marker placement section 51 in the axial direction X is not particularly limited as long as it is greater than the axial length of the marker 30, but is 0.5 mm or more, for example, 0.7 mm to 3 mm.

[0036] The protrusion amount P, which is half the difference in inner diameters obtained by subtracting the inner diameter D1 of the marker placement portion 51 from the inner diameter D2 of the marker-absent portion 52, is greater than the radial thickness T of the marker placed in the marker placement portion 51. Note that the protrusion amount P of the marker placement portion 51 may be smaller than the radial thickness T of the marker 30 placed in the marker placement portion 51. The protrusion amount P of the marker placement portion 51 is not particularly limited, but is preferably 0.5 to 1.2 times the thickness T of the marker 30 placed in the marker placement portion 51, and is 0.04 mm in this embodiment. The inner diameter D2 of the marker-absent portion 52 is not particularly limited, but is preferably 0.4 mm to 1.1 mm, and is 0.5 mm in this embodiment.

[0037] The proximal end of the shaft 2 is fixed liquid-tight to the hub 3 by adhesive, heat fusion, a fastener (not shown), or the like. The hub 3 functions as an insertion port for a guide wire or medical device into the lumen 5, an injection port for a medicinal solution, an embolic substance, a contrast agent, etc. into the lumen 5, and also functions as a gripping portion when operating the catheter 1. The material of the hub 3 is not particularly limited, but suitable examples include thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer.

[0038] The anti-kink protector 4 is made of an elastic material and is provided so as to surround the periphery of the shaft 2, and prevents kinking of the shaft 2 at the connection portion between the shaft 2 and the hub 3. Suitable materials for the anti-kink protector 4 include, for example, natural rubber, silicone resin, polyester elastomer, polyamide elastomer, and polyurethane elastomer.

[0039] As described above, the catheter 1 of this embodiment is a catheter 1 equipped with a shaft 2 having a lumen 5 that connects from the tip to the base end, and the shaft 2 has an X-ray opaque marker 30 at at least one location in the axial direction X of the shaft 2, and the inner diameter D1 of the marker placement section 51 in which the marker 30 is placed is smaller than the inner diameter D2 of the marker-absent section 52 in which the marker 30 is not placed, and the surface roughness of the inner surface of the marker placement section 51 is greater than the surface roughness of the inner surface of the marker-absent section 52.

[0040] The catheter 1 configured as described above can improve the retention of a guidewire inserted into the lumen 5 by virtue of the small inner diameter of the marker placement section 51. Furthermore, because the inner diameter D2 of the marker-absent section 52 is larger than the inner diameter D1 of the marker placement section 51, the sliding resistance of the catheter 1 as a whole with the guidewire can be reduced. Furthermore, the surface roughness of the inner surface 11 of the marker placement section 51, which has a smaller inner diameter and is therefore more likely to come into contact with the guidewire than the marker-absent section 52, is greater than the surface roughness of the inner surface of the marker-absent section 52, so the sliding resistance of the catheter 1 as a whole with the guidewire can be reduced. Therefore, the catheter 1 can effectively retain a guidewire inserted into the lumen 5 and can improve the slidability of the guidewire.

[0041] Furthermore, the protrusion amount P, which is half the difference in inner diameters obtained by subtracting the inner diameter D1 of the marker placement portion 51 from the inner diameter D2 of the marker-absent portion 52, is greater than the thickness T of the marker 30 in the radial direction of the shaft 2. This allows the marker 30 to be embedded smoothly inside the shaft 2, thereby preventing a decrease in the strength of the shaft 2 due to the placement of the marker 30.

[0042] Alternatively, the protrusion amount P, which is half the difference in inner diameters obtained by subtracting the inner diameter D1 of the marker placement section 51 from the inner diameter D2 of the marker-absent section 52, may be smaller than the thickness T of the marker 30 in the radial direction of the shaft 2. This prevents the wall thickness of the marker placement section 51 from becoming unnecessarily large due to the placement of the marker 30. It also prevents the outer surface of the marker placement section 51 from protruding radially outward. This prevents a decrease in the ease of inserting the catheter 1 into a biological lumen.

[0043] The catheter 1 also has a reinforcing body 20 comprising a plurality of wires 21 braided into a tubular shape and disposed between the outer surface 41 and inner surface 11 of the shaft 2, and at least a portion of the reinforcing body 20 is disposed between the marker 30 and the outer surface of the shaft 2. This allows the reinforcing body 20 to effectively prevent the marker 30 from falling off or shifting from the shaft 2. Furthermore, during manufacturing of the catheter 1, the reinforcing body 20 can be placed over the inner layer 10 with the marker 30 already disposed thereon, thereby preventing the marker 30 from shifting from the inner layer 10 before the outer layer 40 is disposed, facilitating manufacturing.

[0044] Furthermore, the marker placement section 51 has one distal marker placement section 53 located at the most distal end, and at least one base marker placement section 54 located closer to the base end than the marker placement section 51, and the inner diameter of the distal marker placement section 53 is smaller than the inner diameter of the base marker placement section 54. As a result, the catheter 1 is provided with a plurality of markers 30, and the distal marker placement section 53 effectively improves the retention of the guidewire, and the base marker placement section 54 effectively improves the slidability of the guidewire.

[0045] The catheter 1 also comprises a shaft 2 having a lumen 5 that extends from the tip to the base end, and the shaft 2 has a reinforcing member 20 comprising a plurality of wires 21 braided into a tubular shape and arranged in at least a portion between the inner surface 11 of the shaft 2 that forms the lumen 5 and the outer surface 41 of the shaft 2, and at least one radiopaque marker 30 arranged between the reinforcing member 20 and the outer surface 41, and the inner diameter D1 of the marker arrangement portion 51 of the shaft 2 in which the marker 30 is arranged is smaller than the inner diameter D2 of the marker absence portion 52 of the shaft 2 in which the marker 30 is not arranged, and the difference between the inner diameter D2 of the shaft 2 in the axial direction of the shaft 2 adjacent to the marker 30 and the inner diameter D1 of the shaft 2 in the portion in which the marker 30 is arranged is defined as the inner diameter difference, and half of the inner diameter difference obtained by subtracting the inner diameter of the marker arrangement portion 51 from the inner diameter D2 of the marker absence portion 52 is greater than the thickness T of the marker 30 in the radial direction of the shaft 2.

[0046] In the catheter 1 configured as described above, the inner diameter D1 of the marker placement section 51 is smaller than the reduction in inner diameter D2 of the marker-absent section 52 due to the presence of the marker 30, thereby improving the retention of the guidewire inserted into the lumen 5. Furthermore, because the inner diameter D2 of the marker-absent section 52 is larger than the inner diameter D1 of the marker placement section 51, the sliding resistance of the catheter 1 as a whole with the guidewire can be reduced.

[0047] The present invention is not limited to the above-described embodiment, and various modifications may be made by those skilled in the art within the technical spirit of the present invention. For example, the catheter 1 may be inserted through a blood vessel other than the artery in the arm. [Explanation of symbols]

[0048] 1 catheter 2 shafts 5 lumens 10 Inner layer 11 Inner surface 20 Reinforcement 21 Wire rod 30 markers 31 Tip Marker 32 Base Marker 41 External surface 51 Marker placement section 52 No Marker 53 Tip marker placement section 54 Base marker placement section 55 Constant inner diameter part 56 Tapered tip 57 Base end tapered section D1 Inner diameter of marker placement area D2 Inner diameter of the part without marker P protrusion amount X axis direction

Claims

1. A catheter having a shaft with a lumen communicating from the distal end to the proximal end, the shaft has a radiopaque marker at least at one position in the axial direction of the shaft; an inner diameter of a marker placement portion of the shaft in which the marker is placed is smaller than an inner diameter of a marker absence portion of the shaft in which the marker is not placed; the surface roughness of the inner surface of the marker placement portion is greater than the surface roughness of the inner surface of the marker absence portion; A catheter characterized in that half of the difference in inner diameter obtained by subtracting the inner diameter of the marker-placed portion from the inner diameter of the marker-absent portion is greater than the thickness of the marker in the radial direction of the shaft.

2. A catheter having a shaft with a lumen communicating from the distal end to the proximal end, The shaft has a radiopaque marker at at least one location in the axial direction of the shaft, and a reinforcing body disposed between an outer surface and an inner surface of the shaft and including a plurality of wires braided into a tubular shape, an inner diameter of a marker placement portion of the shaft in which the marker is placed is smaller than an inner diameter of a marker absence portion of the shaft in which the marker is not placed; the surface roughness of the inner surface of the marker placement portion is greater than the surface roughness of the inner surface of the marker absence portion; half of the difference in inner diameter obtained by subtracting the inner diameter of the marker placement portion from the inner diameter of the marker absence portion is smaller than the thickness of the marker in the radial direction of the shaft, A catheter, characterized in that at least a portion of the reinforcement is disposed between the marker and the outer surface of the shaft.

3. A catheter having a shaft with a lumen communicating from the distal end to the proximal end, the shaft has a radiopaque marker at least at one position in the axial direction of the shaft; an inner diameter of a marker placement portion of the shaft in which the marker is placed is smaller than an inner diameter of a marker absence portion of the shaft in which the marker is not placed; the surface roughness of the inner surface of the marker placement portion is greater than the surface roughness of the inner surface of the marker absence portion; half of the difference in inner diameter obtained by subtracting the inner diameter of the marker placement portion from the inner diameter of the marker absence portion is smaller than the thickness of the marker in the radial direction of the shaft, the marker placement section has one distal marker placement section on the distal end side and at least one proximal marker placement section on the proximal end side of the marker placement section, A catheter characterized in that the inner diameter of the distal marker placement portion is smaller than the inner diameter of the proximal marker placement portion.

4. A catheter having a shaft with a lumen communicating from the distal end to the proximal end, the shaft has a radiopaque marker at least at one position in the axial direction of the shaft; the marker placement portion of the shaft, in which the marker is placed, has a constant inner diameter portion having a constant inner diameter along the axial direction, the inner diameter of the constant inner diameter portion being smaller than the inner diameter of a marker absence portion of the shaft, in which no marker is placed; A catheter characterized in that the surface roughness of the inner surface of the constant inner diameter portion of the marker placement portion is greater than the surface roughness of the inner surface of the marker-free portion.

5. The catheter according to claim 4, wherein half of the difference in inner diameter obtained by subtracting the inner diameter of the marker-placed portion from the inner diameter of the marker-absent portion is greater than the thickness of the marker in the radial direction of the shaft.

6. The catheter according to claim 4, wherein half of the difference in inner diameter obtained by subtracting the inner diameter of the marker-placed portion from the inner diameter of the marker-absent portion is smaller than the thickness of the marker in the radial direction of the shaft.

7. a reinforcing body disposed between an outer surface and an inner surface of the shaft and including a plurality of wires braided into a tubular shape; 7. The catheter according to any one of claims 4 to 6, wherein at least a portion of the reinforcement is disposed between the marker and the outer surface of the shaft.

8. the marker placement section has one distal marker placement section on the most distal side and at least one proximal marker placement section on the proximal side of the marker placement section, The catheter according to any one of claims 4 to 7, wherein the inner diameter of the distal marker placement portion is smaller than the inner diameter of the proximal marker placement portion.

9. A catheter having a shaft with a lumen communicating from the distal end to the proximal end, The shaft a reinforcing member including a plurality of wires braided in a tubular shape and disposed at least partially between the inner surface of the shaft forming the lumen and the outer surface of the shaft; at least one radiopaque marker disposed between the reinforcement body and the outer surface; an inner diameter of a marker placement portion of the shaft in which the marker is placed is smaller than an inner diameter of a marker absence portion of the shaft in which the marker is not placed; The difference between the inner diameter of the shaft at a portion adjacent to the marker in the axial direction of the shaft and the inner diameter of the shaft at a portion where the marker is arranged is defined as an inner diameter difference, A catheter characterized in that half of the difference in inner diameter obtained by subtracting the inner diameter of the marker-placed portion from the inner diameter of the marker-absent portion is greater than the thickness of the marker in the radial direction of the shaft.

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