WO2023095694A1

WO2023095694A1 - Catheter

Info

Publication number: WO2023095694A1
Application number: PCT/JP2022/042508
Authority: WO
Inventors: 隆史伊藤; 光起星; 元裕船木
Original assignee: テルモ株式会社
Priority date: 2021-11-25
Filing date: 2022-11-16
Publication date: 2023-06-01

Abstract

Provided is a catheter capable of improving the catheter insertability into a lumen in vivo while maintaining retention and sliding properties of a guidewire.　A catheter (1) provided with a shaft (2) having a lumen (5) extending from the tip to the base, wherein: the shaft (2) has a reinforcing body (20) provided with a plurality of tubularly braided reinforcing wires (21) and a radiopaque marker (30) placed at least one position in the axial direction (X) of the shaft (2); the marker (30) is placed radially outward from the reinforcing body (20) on the shaft (2); the inner diameter (D1) of the lumen (5) in the marker placement section (51) of the shaft (2) where the marker (30) is placed is smaller than the inner diameter (D2) in the marker absence section (52) of the shaft (2) where the marker (30) is not placed; and the outer diameter (D6) of the marker placement section (51) is substantially identical with the outer diameter (D7) of the marker absence section (52).

Description

catheter

The present invention relates to catheters used in lumens such as blood vessels.

In recent years, intraluminal treatments such as blood vessels using catheters have been actively performed because the surgical invasiveness is very low. For example, catheters that are used to selectively introduce into complex branching blood vessels in the body are generally pushed along a guide wire that has been previously introduced into the blood vessel to deliver therapeutic drugs and diagnostic imaging. Agents and the like can be distributed through the lumen. In addition, the catheter has a radiopaque marker placed on the shaft so that the position within the lumen can be recognized from outside the body (see, for example, Patent Document 1).

Patent Document 1 describes a catheter in which the inner diameter of the lumen and the outer diameter of the catheter are constant by providing a marker on the small-diameter portion formed by partially deforming the reinforcing body wound around the inner layer.

International Publication No. 2017/104465

In the catheter described in Patent Document 1, since the inner diameter of the portion where the marker is placed is the same as the inner diameter of the portion without the marker, the inner diameter of the catheter is large in order to maintain the slidability between the guide wire and the inner surface of the catheter. , the difference between the outer diameter of the guidewire is large and the guidewire is not sufficiently supported. Therefore, there is a possibility that the ease of inserting the catheter into the body lumen is reduced.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-described problems, and it is an object of the present invention to provide a catheter that can improve the insertability of the catheter into a biological lumen while maintaining the holdability and slidability of the guidewire. aim.

A catheter for achieving the above object is a catheter comprising a shaft having a lumen communicating from a distal end to a proximal end, the shaft comprising a reinforcing body having a plurality of tubularly braided reinforcing wires, and an axis of the shaft. a radiopaque marker positioned in at least one central location, said marker positioned radially outward of said shaft relative to said stiffener, said marker positioned on said shaft. The inner diameter of the lumen of the marker-placed portion of the shaft is smaller than the inner diameter of the lumen of the marker-free portion of the shaft where the marker is not placed, and the outer diameter of the marker-placed portion is substantially equal to the outer diameter of the marker-free portion. are identical.

The catheter configured as described above can effectively hold the guidewire inserted into the lumen by the marker placement portion with a small inner diameter. In addition, since the inner diameter of the lumen in the marker-absent portion is larger than the inner diameter of the lumen in the marker-placed portion, the sliding resistance of the catheter as a whole against the guidewire can be reduced. In addition, since the outer diameter of the marker-placed portion is substantially the same as the outer diameter of the marker-absent portion, it is possible to improve the insertability of the catheter into the biological lumen.

The outer diameter of the marker may be equal to or less than the outer diameter of the reinforcing body. As a result, even if the outer diameter of the portion where the marker is placed is substantially the same as the outer diameter of the portion where the marker is absent, it is possible to prevent the layer that covers the marker on the shaft from becoming thinner than necessary, thereby suppressing a decrease in the strength of the shaft. can. In addition, since the marker is arranged so as to completely enter the portion of the reinforcing body whose diameter is partially reduced, the reinforcing body can effectively suppress unintended movement of the marker in the axial direction.

The shape of the outer peripheral surface of the marker may be substantially polygonal in a cross section perpendicular to the axial direction of the shaft. As a result, the contact area between the marker and the member covering the outer peripheral surface of the marker is increased, the joint is stably joined, and the strength reduction of the shaft can be suppressed.

The outer diameter of the shaft is 0.5 mm or more and 0.9 mm or less, the inner diameter of the lumen of the marker placement portion is 0.38 mm or more and 0.55 mm or less, and the inner diameter of the lumen of the marker absent portion is 0. .45 mm or more and 0.6 mm or less may be used. As a result, it is possible to realize a catheter with appropriate dimensions that can improve the insertability of the catheter into a biological lumen while maintaining the guidewire holdability and slidability.

It is a top view showing a catheter concerning an embodiment. FIG. 4 is a cross-sectional view showing the distal end portion of the catheter according to the embodiment; FIG. 4 is an enlarged cross-sectional view showing the distal end portion of the catheter according to the embodiment; FIG. 3 is a plan view showing the outer layer of the catheter according to the embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the dimensions in the drawings may be exaggerated for convenience of explanation and may differ from the actual dimensions. Further, in the present specification and drawings, constituent elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description. In this specification, the side of the catheter that is inserted into the biological lumen is called the "distal side", and the side that is operated is called the "proximal side". Further, in this specification, the range "X to Y" includes X and Y and means "X or more and Y or less".

The catheter 1 according to this embodiment is introduced into a blood vessel from the radial artery of the arm, the femoral artery of the leg, or the peripheral artery of the lower limb, is inserted into the artery of the lower limb, and is used for treatment, diagnosis, and the like. Catheter 1 is, for example, a support catheter, but may be a device for other uses. Arteries of the lower extremities are arteries near and more distal to the aortoiliac bifurcation. As shown in FIG. 1, the catheter 1 has an elongated shaft 2, a hub 3 connected to the proximal end of the shaft 2, and an anti-kink protector 4 provided at the joint between the shaft 2 and the hub 3. ing.

As shown in FIGS. 1 to 4, the shaft 2 is a tubular member having flexibility, and a lumen 5 is formed inside from the proximal end to the distal end. A guide wire is passed through the lumen 5 when the catheter 1 is inserted into the blood vessel. The lumen 5 can also be used as a passageway for liquid medicines, embolic substances, contrast media, medical instruments, and the like.

Although the effective length of the shaft 2 is not particularly limited, it is preferably 200 mm to 2600 mm, more preferably 400 mm to 2300 mm, still more preferably 600 mm to 2300 mm, and 1500 mm in this embodiment. This allows the catheter 1 to reach the arteries of the lower extremities. The effective length of the shaft 2 is the length of a 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 tip of the kink protector 4 to the tip of the shaft 2 . The effective length of the shaft 2 is 1200 mm or more when introduced from the arm artery, 650 mm or more when introduced from the femoral artery, and 300 mm or more when introduced from the distal part of the dorsalis pedis artery or posterior tibial artery. is preferred.

The shaft 2 is composed of a plurality of layers, including an inner layer 10 forming an inner surface 11 of the lumen 5, a reinforcing member 20 arranged radially outside the inner layer 10, and a reinforcing member 20 arranged radially outside the reinforcing member 20. and an outer layer 40 formed radially outside the inner layer 10 , the reinforcing body 20 and the markers 30 . The radially outer side is the side away from the axial center of the shaft 2 .

Although the inner diameter of the inner layer 10 is not particularly limited, it is preferably 0.2 mm to 1.2 mm, more preferably 0.4 mm to 1.1 mm, still more preferably 0.4 mm to 0.55 mm. The inner and outer diameters of the inner layer 10 are smaller than the portions adjacent to the shaft 2 in the axial direction X at the positions covered with the markers 30 .

The inner layer 10 has a lumen 5 formed therein. The constituent material of 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). A resin, a polyamide elastomer, a polyester, a polyester elastomer, or the like may be used.

The reinforcing body 20 is formed by braiding a plurality of reinforcing wires 21 into a tubular shape around the outer circumference of the inner layer 10 so as to have gaps. The reinforcing body 20 is formed with a small diameter portion 22 having a locally small outer diameter for arranging the marker 30 . The length of the small diameter portion 22 in the axial direction X is preferably equal to or greater than the length of the marker 30 in the axial direction X so that the marker 30 can be accommodated. The reinforcing body 20 may be wound with the reinforcing wire 21 while changing the winding direction such as horizontal winding in the same direction, right winding or left winding, and the winding pitch, the inter-grid distance, the inclination angle with respect to the circumferential direction, etc. The configuration is not particularly limited. For example, one reinforcing wire 21 may be coiled in one direction and formed into a tubular shape with a gap.

The reinforcing body 20 may be arranged all over the shaft 2 in the axial direction X, or may be arranged only partially. In this embodiment, the distal end of the reinforcing body 20 is located near the distal end of the shaft 2 and slightly closer to the proximal side than the distal end of the shaft 2 . The proximal end of the reinforcing body 20 is located in the vicinity of the proximal end of the shaft 2 and slightly to the distal side of the proximal end of the shaft 2 . Since the portion of the distal end of the shaft 2 where the reinforcing member 20 is not arranged has a high degree of flexibility, it is easy to change the bending direction along the guidewire and reduce the burden on the living tissue in contact.

The wire diameter (diameter) of the reinforcing wire 21 is not particularly limited, but is preferably 0.03 mm to 0.08 mm, more preferably 0.03 mm to 0.06 mm, still more preferably 0.04 mm to 0.06 mm. Yes, and is 0.03 mm in this embodiment.

The reinforcing wire 21 can be made of stainless steel, platinum (Pt), tungsten (W) or other metal wire, resin fiber, carbon fiber, glass fiber, or the like. A round wire, an elliptical wire, or a flat wire may be used. Each reinforcing wire 21 may be used as one wire for braiding, and a bundle of two or more reinforcing wires 21 may be used as one braiding wire. may be used as one line.

The marker 30 is an X-ray opaque (X-ray contrast) tubular body that enters the small diameter portion 22 from the outside in the radial direction. When arranging the marker 30, after placing the reinforcing body 20 having a substantially constant outer diameter along the axial direction X around the outer periphery of the inner layer 10 having a substantially constant outer diameter along the axial direction X, A tubular body made of a material containing an X-ray opaque substance is arranged so as to surround the inner layer 10 and the reinforcing body 20 . After that, the tubular body is crimped while being sandwiched from two or more locations facing each other on the radially outer side, and crimping is repeatedly performed while gradually shifting the crimped positions in the circumferential direction, thereby reducing the diameter of the entire marker 30. be done. As a result, a plurality of concave portions 31 and a plurality of convex portions 32 are alternately formed on the outer peripheral surface of the tubular body. Therefore, the cross-sectional shape of the outer peripheral surface of the marker 30 in the cross section perpendicular to the axial direction X of the shaft 2 is non-circular, preferably substantially polygonal. In this embodiment, the recess 31 is formed in a groove shape extending in the axial direction X of the shaft 2 . The convex portion 32 is formed in a beam shape extending in the axial direction X of the shaft 2 . The concave portions 31 and the convex portions 32 are arranged substantially evenly in the circumferential direction of the marker 30 . The number of concave portions 31 and convex portions 32 is not particularly limited, but the greater the number, the closer the cross-sectional shape of the marker 30 is to a circular shape. Note that the concave portion 31 does not have to be groove-shaped. Moreover, the convex part 32 may not be beam-shaped. For example, the concave portions 31 and the convex portions 32 may be randomly arranged. When the tubular body is contracted to form the marker 30 , the reinforcing body 20 on which the marker 30 is arranged is contracted together with the marker 30 .

The form of the marker 30 is not limited to this. For example, the shape of the marker 30 before crimping may be C-shaped in a cross section orthogonal to the axial direction X. Alternatively, each marker 30 may be a coil of radiographic metal wire, for example of circular, oval, square or rectangular cross-section. The number of markers 30 is one or more, but may be two, three, or four or more.

Although the thickness of the marker 30 is not particularly limited, it is preferably 0.02 mm to 0.1 mm, more preferably 0.03 mm to 0.08 mm, still more preferably 0.03 mm to 0.04 mm. is 0.03 mm.

Although the length of the marker 30 in the axial direction is not particularly limited, it is preferably 0.5 mm to 5 mm, more preferably 0.7 mm to 3 mm, still more preferably 0.9 mm to 2 mm.

The constituent material of the marker 30 is preferably a material kneaded with an X-ray contrast agent such as metal powder of platinum, gold, silver, tungsten, iridium or alloys thereof, barium sulfate, bismuth oxide, or a coupling compound thereof. Alternatively, a metal coil or contrasting solder may be used.

The outer layer 40 is a tubular body arranged around the inner layer 10 , the reinforcing body 20 and the marker 30 . 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, still more preferably 0.65 mm to 0.9 mm, In this embodiment, it 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 .

The constituent material of the outer layer 40 is, for example, polyolefin (eg, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more thereof), polyvinyl chloride, Polyamides, polyester elastomers, polyamide elastomers, polyurethanes, polyurethane elastomers, polyimides, fluorine resins and other polymeric materials, thermoplastic resins such as mixtures thereof, and thermosetting resins such as epoxy resins can be used. The outer layer 40 may be mixed with an X-ray opaque substance, and the constituent material of the outer layer 40 may be the same as the constituent material of the inner layer 10 .

The shaft 2 includes, in the axial direction X, a plurality of marker placement portions 51 in which the markers 30 are placed and a plurality of marker absent portions 52 in which the markers 30 are not placed. The marker-placed portions 51 and the marker-absent portions 52 are alternately arranged in the axial direction X. As shown in FIG. The outer diameter D6 of the marker placement portion 51 is the same as or substantially the same as the outer diameter D7 of the marker absent portion 52 . It should be noted that the fact that the outer diameter is substantially the same means that there is a slight difference in shape on the outer peripheral surface due to differences in configuration, such as whether the marker 30 or the reinforcing member 20 is provided inside the outer peripheral surface. Also, when it can be judged that the outer diameters are substantially the same as a whole, it means that the outer diameters are substantially the same.

The inner diameter D1 of the lumen 5 of each marker placement portion 51 is smaller than the inner diameter D2 of the lumen 5 of the marker absent portion 52 . Accordingly, by arranging the markers 30 , it is possible to prevent the strength of the shaft 2 from being lowered due to the inner layer 10 becoming thinner than necessary. In addition, since the difference between the inner diameter D1 of the lumen 5 of the marker placement portion 51 and the outer diameter of the guidewire is small, it is easy to hold (support) the guidewire. In addition, since the marker placement portion 51 is provided only in a portion of the catheter 1 in the axial direction X, the sliding resistance of the catheter 1 as a whole with respect to the guide wire can be reduced.

Each marker placement portion 51 has, on its inner peripheral surface, a constant inner diameter portion 55 having a substantially constant inner diameter D1, a tip tapered portion 56 having an inner diameter that decreases toward the distal end from the constant inner diameter portion 55, and a constant inner diameter portion. and a proximal tapered portion 57 having an inner diameter that decreases from 55 in the proximal direction. Since each marker placement portion 51 has a distal tapered portion 56 and a proximal tapered portion 57 , it is possible to prevent the guide wire passing through the lumen 5 from getting caught in the marker placement portion 51 . The length L of the marker placement portion 51 in the axial direction X is not particularly limited as long as it is longer than the axial length of the marker 30, but is, for example, 0.5 mm or more, preferably 0.7 mm to 3 mm.

Although the inner diameter D1 of the lumen 5 of the marker placement portion 51 is not particularly limited, it is preferably 0.38 mm to 0.55 mm. The inner diameter D2 of the lumen 5 of the marker absent portion 52 is not particularly limited, but is preferably 0.45 mm to 0.60 mm. The outer diameter of the catheter is not particularly limited, but is preferably 0.70 mm to 0.90 mm, and the difference between the inner diameter D2 of the lumen 5 of the marker-free portion 52 and the inner diameter D1 of the lumen 5 of the marker-placed portion 51 is not particularly limited. is preferably 0.03 mm to 0.06 mm.

The outer diameter D3 of the marker 30 (the maximum outer diameter when the outer diameter D3 of the marker 30 differs depending on the position) is the outer diameter D4 of the reinforcing body 20 arranged in the adjacent marker absent portion 52 (the outer diameter D4 of the reinforcing body 20 is less than or equal to the maximum outer diameter), preferably less than the outer diameter D4. Accordingly, by arranging the markers 30 , it is possible to prevent the outer layer 40 on the radially outer side of the markers 30 from becoming unnecessarily thin and reducing the strength of the shaft 2 . Furthermore, it is possible to prevent the outer diameter D<b>6 of the marker-placed portion 51 from becoming larger than the outer diameter D<b>7 of the marker-absent portion 52 .

Also, the outer diameter D5 of the small diameter portion 22 of the reinforcing body 20 arranged in the marker placement portion 51 is smaller than the outer diameter D4 of the reinforcing body 20 arranged in the marker absent portion 52 . As a result, it is possible to effectively prevent the markers 30 arranged radially outside the reinforcing member 20 of the marker arrangement portion 51 from shifting in the axial direction X both during manufacture and during use of the catheter 1 . In addition, since the length of the reinforcing member 20 in the axial direction X is longer than the length of the marker 30 in the axial direction X, when the marker 30 is crimped to reduce its diameter and is placed, the marker 30 pushes the reinforcing member 20 to contract. The diameter of the reinforcing body 20 is also reduced at a position away from the marker 30 . Therefore, when the marker 30 is placed, the diameter of the reinforcing body 20 changes smoothly in the vicinity of the marker 30, and the inner peripheral surface of the lumen 5 including the distal tapered portion 56, the constant inner diameter portion 55, and the proximal tapered portion 57 is changed. is formed smoothly. Therefore, it is possible to prevent the guide wire passing through the lumen 5 from being caught in the marker placement portion 51 .

The base end of the shaft 2 of the hub 3 is liquid-tightly fixed with an adhesive, heat-sealing, or a fastener (not shown). The hub 3 functions as an insertion port for a guide wire and medical instruments into the lumen 5, an injection port for a drug solution, an embolic substance, a contrast medium, etc., into the lumen 5, and the like, and also serves as a grip when operating the catheter 1. also functions as The material constituting the hub 3 is not particularly limited, but thermoplastic resins such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer can be suitably used.

The anti-kink protector 4 is made of an elastic material that surrounds the circumference of the shaft 2 and suppresses kinking of the shaft 2 at the connecting portion between the shaft 2 and the hub 3 . For example, natural rubber, silicone resin, polyester elastomer, polyamide elastomer, polyurethane elastomer, etc. can be suitably used as the constituent material of the kink resistant protector 4 .

As described above, the catheter 1 according to this embodiment includes the shaft 2 having the lumen 5 communicating from the distal end to the proximal end. and a radiopaque marker 30 positioned at least one location in the axial direction X of the shaft 2 , the marker 30 being larger in diameter of the shaft 2 than the reinforcement 20 . The inner diameter D1 of the lumen 5 of the marker-placed portion 51 of the shaft 2, which is arranged on the direction outer side and in which the marker 30 is arranged, is smaller than the inner diameter D2 of the marker-free portion 52 of the shaft 2, in which the marker 30 is not arranged. The outer diameter D6 of the portion 51 is the same or substantially the same as the outer diameter D7 of the marker absent portion 52 . “Substantially the same” means that the outer diameter D6 of the marker-placed portion 51 and the outer diameter D7 of the marker-absent portion 52 are not only numerically the same but also practically the same.

Practically identical means that the difference between the outer diameter D6 of the marker-placed portion 51 and the outer diameter D7 of the marker-absent portion 52 is 0 to 0.1 mm, preferably 0 to 0.05 mm, more preferably 0.01 to 0.03 mm. means that: The outer diameter measurement method is not particularly limited, but the outer diameter and outer diameter difference are compared by measuring the outer diameter at the middle between the tip and the proximal end of the marker with a laser outer diameter device.

The catheter 1 configured as described above can improve retention of the guide wire inserted into the lumen 5 by the marker placement portion 51 having a small inner diameter. Moreover, since the inner diameter D2 of the marker-absent portion 52 is larger than the inner diameter D1 of the marker-placed portion 51, the sliding resistance of the catheter 1 as a whole with respect to the guide wire can be reduced. In addition, since the outer diameter D6 of the marker-placed portion 51 is substantially the same as the outer diameter D7 of the marker-absent portion 52, the insertability of the catheter 1 into the body lumen can be improved. Therefore, the catheter 1 can improve the ease of inserting the catheter 1 into the body lumen while maintaining the guide wire holdability and slidability.

Also, the outer diameter D3 of the marker 30 may be equal to or less than the outer diameter D4 of the reinforcing body 20. As a result, even if the outer diameter D6 of the marker-placed portion 51 is substantially the same as the outer diameter D7 of the marker-absent portion 52, the outer layer 40 covering the marker 30 is prevented from becoming thinner than necessary and the strength of the shaft 2 is reduced. can. In addition, since the marker 30 is arranged on the small diameter portion 22 of the reinforcing member 20, the unintended movement of the marker 30 in the axial direction X can be effectively suppressed by the reinforcing member 20. .

Also, the shape of the outer peripheral surface of the marker 30 may be polygonal in a cross section perpendicular to the axial direction X of the shaft 2 . As a result, the contact area between the marker 30 and the outer layer 40 covering the outer peripheral surface of the marker 30 is increased, and the markers are stably joined, thereby suppressing a decrease in the strength of the shaft 2 .

The outer diameter of the shaft 2 is 0.6 mm or more and 0.9 mm or less, the inner diameter D1 of the lumen 5 of the marker placement portion 51 is 0.38 mm or more and 0.55 mm or less, and the lumen 5 of the marker absent portion 52 is 0.38 mm or more and 0.55 mm or less. The inner diameter D2 of may be 0.45 mm or more and 0.60 mm or less. As a result, the catheter 1 that can improve the ease of inserting the catheter 1 into the body lumen while maintaining the guide wire holdability and slidability can be realized with appropriate dimensions.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art within the technical concept of the present invention. For example, in the embodiment described above, a plurality of marker arrangement portions 51 are provided, but only one may be provided. Moreover, in one or more of the plurality of marker-placed portions, the outer diameter of the marker-placed portion may be different from the outer diameter of the marker-absent portion. In addition, the inner diameters D1 of the lumens 5 of the plurality of marker placement portions 51 may be the same or different. The catheter 1 may also be inserted into bile ducts, trachea, esophagus, urethra, or other biological lumens or body cavities and used for treatment, diagnosis, and the like.

This application is based on Japanese Patent Application No. 2021-190785 filed on November 25, 2021, and the disclosure thereof is incorporated by reference.

1 Catheter 2 Shaft 5 Lumen 10 Inner Layer 11 Inner Surface 20 Reinforcement 21 Reinforcement Line 30 Marker 51 Marker Placement Part 52 Marker Absence D1 Inner Diameter of Marker Placement Lumen D2 Marker Absence Lumen Inner Diameter D3 Outer Diameter of Marker D4 Reinforcement Body outer diameter D5 Small diameter part outer diameter D6 Marker placement part outer diameter D7 Marker absent part outer diameter X axial direction

Claims

A catheter comprising a shaft having a lumen communicating from a distal end to a proximal end,
the shaft has a reinforcing body comprising at least one reinforcing line arranged in a tubular shape;
a radiopaque marker positioned at least one location axially of the shaft;
The marker is arranged radially outward of the shaft relative to the reinforcing body,
The inner diameter of the catheter lumen in the marker-placed portion of the shaft where the marker is placed is smaller than the inner diameter of the catheter lumen in the marker-absent portion of the shaft where the marker is not placed,
A catheter, wherein the outer diameter of the marker-placed portion is substantially the same as the outer diameter of the marker-absent portion.
The catheter according to claim 1, wherein the outer diameter of the marker is equal to or less than the outer diameter of the reinforcing body.
The catheter according to claim 1 or 2, wherein the shape of the outer peripheral surface of the marker is polygonal in a cross section perpendicular to the axial direction of the shaft.
The outer diameter of the shaft is 0.70 mm or more and 0.90 mm or less,
The inner diameter of the marker placement portion is 0.38 mm or more and 0.55 mm or less,
The catheter according to any one of claims 1 to 3, wherein the inner diameter of the marker absent portion is 0.45 mm or more and 0.60 mm or less.