JP7555487B2 - catheter - Google Patents

Description

The present invention relates to a catheter.

Balloon catheters are known that are used to expand narrowed or blocked areas in blood vessels to ensure blood flow. For example, Patent Document 1 discloses a balloon catheter in which a circumferentially expandable balloon is disposed on the outer periphery of the shaft body near the tip.

JP 2013-223663 A

In the balloon catheter described in Patent Document 1, the shaft body may be composed of multiple tubes to improve pushability (pushing force) while also improving safety. For example, the shaft body may be configured such that a metal tube is disposed at the base end close to the surgeon's hand to improve pushability, and a plastic tube is disposed at the tip end inserted into the body to improve safety. However, in such cases, there is a problem in that a sudden change in rigidity causes stress concentration at the connection between the two tubes due to the large difference in rigidity between the metal tube and the plastic tube.

These issues are not limited to balloon catheters with balloons, but are common to all catheters. Furthermore, these issues are not limited to the vascular system, but are common to all catheters inserted into biological lumens, such as the lymphatic system, biliary system, urinary system, respiratory system, digestive system, secretory glands, and reproductive organs.

The present invention has been made to solve at least part of the above-mentioned problems, and aims to suppress stress concentration at the connection points of the tubes when the shaft body is constructed from multiple tubes made of different materials.

The present invention has been made to solve at least some of the above-mentioned problems and can be realized in the following forms.

(1) According to one aspect of the present invention, a catheter is provided. The catheter includes a first tube made of a metal material and a second tube made of a resin material connected to a distal end of the first tube, the first tube having a first cylindrical portion provided at the distal end of the first tube and having a first outer diameter, a second cylindrical portion provided at a proximal end of the first tube and having a second outer diameter larger than the first outer diameter, and a tapered portion provided between the first cylindrical portion and the second cylindrical portion, and a proximal end of the second tube is fixed to an outer circumferential surface of the first cylindrical portion of the first tube.

According to this configuration, the first metal tube has a first cylindrical portion having a first outer diameter provided at the tip end and a second cylindrical portion having a second outer diameter larger than the first outer diameter provided at the base end, so that the tip end of the first tube can be made more flexible than the base end, improving safety. In addition, since the first metal tube has a tapered portion provided between the first cylindrical portion and the second cylindrical portion, the rigidity of the first tube can be gradually changed and stress concentration due to a sudden change in rigidity can be suppressed compared to the case where the first cylindrical portion and the second cylindrical portion are directly connected. Furthermore, since the base end of the second resin tube is fixed to the outer peripheral surface of the first cylindrical portion having the smallest outer diameter of the first metal tube, the rigidity of the shaft body (i.e., the first tube and the second tube) can be gradually changed and stress concentration due to a sudden change in rigidity can be suppressed compared to the case where the second tube is fixed to the second cylindrical portion. As a result, in a catheter having a shaft body composed of multiple tubes made of different materials, stress concentration at the tube connection portion can be suppressed, and damage to the shaft body due to stress concentration can be suppressed. Also, since the first tubular portion is provided in addition to the tapered portion provided for gradual change in rigidity, and the base end portion of the second tube is fixed to the outer circumferential surface of this first tubular portion, a stable and high joint strength between the first tube and the second tube can be obtained compared to the case where the base end is fixed to the tapered portion (inclined surface).

(2) In the catheter of the above form, the outer peripheral surface of the first tubular portion may have a first region and a second region having a surface roughness greater than that of the first region, and the base end of the second tube may be fixed to at least the second region of the outer peripheral surface of the first tubular portion.
For example, it is known that the joining strength of a metal and a resin is lower than that of a metal-metal joint or a resin-resin joint. According to this configuration, the outer peripheral surface of the first cylindrical portion of the first tube has a second region having a surface roughness relatively larger than that of the first region, and the base end of the second tube is fixed to at least the second region of the outer peripheral surface of the first cylindrical portion. Therefore, even when the second tube made of resin is joined (fixed) to the first cylindrical portion made of metal and having a relatively small diameter, as in this configuration, the joining strength between the first tube and the second tube can be suppressed from decreasing. As a result, in a catheter whose shaft body is composed of a plurality of tubes made of different materials, the pressure resistance can be suppressed from decreasing. In addition, by providing the first cylindrical portion separately from the tapered portion provided for gradual change in rigidity and providing the second region having a large surface roughness on the outer peripheral surface of this first cylindrical portion, the surface roughness of the second region can be stabilized compared to the case where a region having a large surface roughness is provided on the tapered portion (inclined surface), and a sufficiently stable and high joining strength between the first tube and the second tube can be obtained.

(3) In the catheter of the above aspect, on the outer peripheral surface of the first tubular portion, the first region may be located closer to the tip side than the second region and adjacent to the second region.
According to this configuration, the first region is located closer to the distal end than the second region to which the base end of the second tube is fixed, so that another member disposed inside the second tube can be attached to the region of the inner or outer circumferential surface of the first cylindrical portion where the first region is formed.

(4) In the catheter of the above aspect, the first region may be provided on the outer peripheral surface of the first tubular portion adjacent to the second region on both sides of the second region.
Since the second region has a larger surface roughness than the first region, the rigidity of the portion of the first tubular portion where the second region is provided is lower than the rigidity of the portion of the first tubular portion where the first region is provided. According to this configuration, since the first region is provided on both sides of the second region, the first tubular portion is connected to the tapered portion through the portion where the first region is provided. Therefore, compared to the case where the first tube is connected to the tapered portion through the portion where the second region is provided, the rigidity of the first tube can be gradually changed, and stress concentration due to a sudden change in rigidity can be suppressed. As a result, damage to the first tube due to stress concentration can be suppressed.

(5) The catheter of the above aspect may further include a core wire disposed inside the second tube, the base end of which is fixed to the tip end of the first tube.
According to this configuration, the catheter includes a core wire disposed inside the second tube and having a base end fixed to the tip end of the first tube, which can further reduce abrupt changes in stiffness between the first tube and the second tube, thereby further preventing damage to the first tube and the second tube due to stress concentration.

(6) In the catheter of the above aspect, the base end of the core wire may be fixed to a region of the inner circumferential surface of the first tubular portion where the first region is formed on a corresponding outer circumferential surface.
According to this configuration, the base end of the core wire is fixed to a region of the inner surface of the first tubular portion where the first region is formed on the corresponding outer surface, thereby enabling the outer diameter of the catheter to be reduced.

(7) In the catheter of the above aspect, the core wire may be made of a cobalt-chromium alloy.
According to this configuration, since the core wire is made of a cobalt-chromium alloy, a sudden change in rigidity between the first tube and the second tube can be more effectively alleviated compared to a case where a stainless steel alloy such as SUS304 is used, and as a result, damage to the first tube and the second tube due to stress concentration can be more effectively prevented.

(8) In the catheter of the above aspect, the first tube may have the same inner diameter at the tip end and the same inner diameter at the base end.
According to this configuration, the inner diameter of the first tube is equal to that of the distal end. In other words, it is not necessary to reduce the inner diameter of the first tube in order to gradually change the stiffness of the first tube. Therefore, for example, when a balloon is provided on the distal end side of the second tube to configure the catheter as a balloon catheter, it is possible to supply/discharge fluid at a sufficient flow rate through the fluid lumen of the first tube, and shorten the inflation/deflation time of the balloon (the time required for the balloon to expand/contract) compared to a case in which the inner diameter of the first tube changes according to the outer diameter.

(9) The catheter of the above form may further include an expandable and contractable balloon arranged on the tip side of the second tube, an inner tube arranged inside the balloon and the second tube, and a tip tip provided at the tip of the inner tube, wherein the tip of the balloon is fixed to the tip tip or the outer peripheral surface of the inner tube, and the base end of the balloon is fixed to the tip of the second tube.
With this configuration, the catheter can be configured as a balloon catheter.

The present invention can be realized in various forms, for example, in the form of a catheter, a balloon catheter, a shaft body for a catheter, and a manufacturing method thereof.

FIG. 1 is an explanatory diagram illustrating a configuration of a catheter. 2 is an explanatory diagram illustrating a cross-sectional configuration taken along line AA in FIG. 1. 1 is an enlarged view of a connection portion between a first tube and a second tube (part B in FIG. 1 ). FIG. 4 is a cross-sectional view of a connection portion between a first tube and a second tube. FIG. FIG. 1 is a diagram illustrating surface roughness. FIG. 1 is a diagram illustrating surface roughness. FIG. 1 is a diagram illustrating a catheter during delivery. FIG. 13 is a diagram illustrating the catheter during balloon expansion. FIG. 11 is an enlarged view of a connecting portion between a first tube and a second tube of a catheter according to a second embodiment. FIG. 11 is an enlarged view of a connecting portion between a first tube and a second tube of a catheter according to a third embodiment. FIG. 13 is an enlarged view of a connecting portion between a first tube and a second tube of a catheter according to a fourth embodiment. FIG. 13 is an enlarged view of a connecting portion between a first tube and a second tube of a catheter according to a fifth embodiment. FIG. 13 is an enlarged view of a connecting portion between a first tube and a second tube of a catheter according to a sixth embodiment. 13 is an enlarged view of a connecting portion between a first tube and a second tube of a catheter according to a seventh embodiment. FIG. FIG. 23 is an explanatory diagram illustrating the configuration of a catheter according to an eighth embodiment. FIG. 13 is an explanatory diagram illustrating the configuration of a catheter according to a ninth embodiment. FIG. 19 is an explanatory diagram illustrating the configuration of a catheter according to a tenth embodiment.

First Embodiment
FIG. 1 is an explanatory diagram illustrating an example of the configuration of a catheter 1. In this embodiment, a balloon catheter is illustrated as the catheter 1. The balloon catheter 1 is inserted into a blood vessel and has a balloon that expands/contracts by supplying/discharging a fluid. The balloon catheter 1 can expand a narrowed or blocked area in a blood vessel with the balloon to ensure blood flow. The balloon catheter 1 may be inserted into a body lumen such as a lymphatic system, a biliary system, a urinary system, a respiratory system, a digestive system, a secretory gland, and a reproductive organ, in addition to the blood vessel. Hereinafter, the balloon catheter 1 is also referred to simply as a "catheter 1."

The catheter 1 includes a first tube 10, a second tube 20, a balloon 30, an inner tube 40, a core wire 50, a distal tip 60, and a connector 70. The first tube 10 and the second tube 20 are collectively referred to as the "shaft body." The catheter 1 can suppress stress concentration at the connection between the first tube 10 and the second tube 20 by having the configuration described below for the first tube 10 and the second tube 20. Note that FIG. 1 shows the balloon 30 in a deflated state.

In FIG. 1, the axis passing through the center of the first tube 10 of the catheter 1 is represented by the axis O (dotted line). For the sake of convenience, FIG. 1 includes parts in which the relative ratio of the sizes of the components is depicted differently from the actual ratio. Also, some of the components are depicted in an exaggerated manner. FIG. 1 also illustrates mutually orthogonal XYZ axes. The X axis corresponds to the longitudinal direction of the catheter 1, the Y axis corresponds to the height direction of the catheter 1, and the Z axis corresponds to the width direction of the catheter 1. The left side (-X axis direction) of FIG. 1 is referred to as the "tip side" of the catheter 1 and each component, and the right side (+X axis direction) of FIG. 1 is referred to as the "base end side" of the catheter 1 and each component. In addition, of the two ends of the catheter 1 and each component in the longitudinal direction (X axis direction), the one end located on the tip side is referred to as the "tip" and the other end located on the base side is referred to as the "base end". In addition, the tip and its vicinity are referred to as the "tip portion", and the base end and its vicinity are referred to as the "base end portion". The distal end side is inserted into the living body, and the proximal end side is operated by an operator such as a doctor. These points are the same in the figures after FIG.

The tip tip 60 is a member disposed at the tip 1d of the catheter 1 and advances through the blood vessel before other members. The tip tip 60 is hollow, with openings at the tip and base ends, and an inner cavity that connects the two openings. The opening at the tip side of the tip tip 60 is also called the "tip side opening 40a". The tip side opening 40a is used to insert and remove a medical device such as a guidewire from the inside of the catheter 1 (specifically, the wire lumen 40L described later). The outer shape of the tip tip 60 is tapered from the base end side to the tip side in order to make the catheter 1 advance smoothly through the biological lumen. The outer diameter and length of the tip tip 60 can be determined arbitrarily. The tip tip 60 is preferably flexible, and can be formed from a resin material such as polyurethane or polyurethane elastomer.

The balloon 30 is a tubular member that can expand and contract in the radial direction (YZ axis direction) of the catheter 1 and has both ends, the tip side and the base side, open. The balloon 30 undergoes out-of-plane deformation and expands (expands in diameter) radially outward by supplying fluid to the space 30L formed inside. The balloon 30 also undergoes in-plane deformation and contracts (contracts in diameter) radially inward by discharging the fluid inside the space 30L. In this way, the balloon 30 can be freely expanded/contracted by supplying/discharging fluid. The expansion pressure, outer diameter, and length of the balloon 30 can be determined arbitrarily. The balloon 30 may have a configuration in which it is folded in a contracted state.

The distal end 38 of the balloon 30 is fixed to the outer circumferential surface of the distal tip 60. The proximal end 39 of the balloon 30 is fixed to the outer circumferential surface of the distal end 28 of the second tube 20. The balloon 30 can be made of a material that can expand and contract with changes in internal pressure, and has flexibility to suppress damage inside the blood vessel and hardness to expand within the lesion. For example, the balloon 30 can be made of polyolefins such as polyethylene, polypropylene, and ethylene-propylene copolymers, polyesters such as polyethylene terephthalate, thermoplastic resins such as polyvinyl chloride, ethylene-vinyl acetate copolymers, crosslinked ethylene-vinyl acetate copolymers, and polyurethanes, polyamide elastomers, polyolefin elastomers, silicone rubber, latex rubber, and the like.

The second tube 20 is a long member extending along the axis O. The second tube 20 has an opening at each of the tip and base ends, and is a hollow, approximately cylindrical shape with an inner cavity (fluid lumen 20L) that communicates both openings on the inside. The second tube 20 has a large diameter section 21, a tapered section 22, and a small diameter section 23 from the tip side to the base end side. The large diameter section 21 is a section in which the outer diameter and inner diameter are larger than those of the small diameter section 23. The tapered section 22 is provided between the large diameter section 21 and the small diameter section 23, and is a section in which the outer diameter and inner diameter gradually become smaller from the tip side to the base end side. The small diameter section 23 is provided at the base end of the second tube 20. A port 40b, which is an opening that communicates between the inside and outside of the cylinder, is formed on the side of the second tube 20. The port 40b is used to insert and remove a medical device such as a guidewire into and from the inside of the catheter 1 (specifically, the wire lumen 40L described later). The outer diameter and length of the second tube 20, and the position, size, and shape of the port 40b can be determined arbitrarily. In the example of Fig. 1, the outer diameter and inner diameter of the second tube 20 on the distal side of the port 40b are different from the outer diameter and inner diameter of the second tube 20 on the proximal side of the port 40b, but these may be the same.

The base end 39 of the balloon 30 is fixed to the outer peripheral surface of the tip portion 28 of the second tube 20. The first tube 10 is fixed to the inner peripheral surface of the small diameter portion 23 of the second tube 20. The second tube 20 is preferably antithrombotic, flexible, and biocompatible, and is formed from a resin material such as polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, or fluororesin. In other words, the second tube 20 is a resin tube.

The inner tube 40 shown in FIG. 1 is an elongated member extending along the axis O, and has a smaller diameter than the second tube 20. The inner tube 40 has an opening at each of the tip and base ends, and is a hollow, approximately cylindrical shape with an inner cavity (wire lumen 40L) that communicates both openings on the inside. The inner tube 40 has a main body portion 41 and a curved portion 42 from the tip side to the base end side. The main body portion 41 is disposed inside the balloon 30 and the second tube 20, and is a portion that extends linearly along the axis O. The curved portion 42 is provided near the end of the base end side of the inner tube 40, and is a portion where the inner tube 40 is curved in a direction away from the axis O (in other words, in the direction of the port 40b). The tip portion 48 of the inner tube 40 is fixed to the tip tip 60. The base end 49 of the inner tube 40 is fixed to the inner peripheral surface of the second tube 20 in a state in which an opening (port 40b) on the side of the second tube 20 and the wire lumen 40L are in communication with each other. The outer diameter and length of the inner tube 40 can be determined arbitrarily.

2 is an explanatory diagram illustrating a cross-sectional configuration along line A-A in FIG. 1. An example of the configuration of the inner tube 40 is shown in the dashed line in the lower part of FIG. 2. As shown in the lower part of FIG. 2, the inner tube 40 of this embodiment has a configuration in which the coil body 402 is embedded inside the thick part 401. The coil body 402 is a single-strand coil formed by winding a single strand of wire. The coil body 402 may be a multiple-strand coil formed by winding multiple strands of wires, a single-strand strand coil formed by winding a strand of wires twisted together from multiple strands, or a multiple-strand strand coil formed by using multiple strands of wires twisted together from multiple strands and winding each strand into multiple strands. By using such an inner tube 40, it is possible to prevent the inner tube 40 from being damaged when the guide wire is inserted into or removed from the wire lumen 40L. The thick portion 401 can be made of a resin material such as polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, fluororesin, etc. The coil body 402 can be made of a metal material such as stainless steel such as SUS304, nickel-titanium alloy, cobalt-chromium alloy, etc.

The core wire 50 is an elongated member extending along the axis O, and has a smaller diameter than the second tube 20 and the inner tube 40. The core wire 50 has a solid, generally cylindrical shape. A tapered section in which the outer diameter gradually changes may be provided between the tip and base ends of the core wire 50. The tapered section may have a configuration in which the outer diameter gradually decreases toward the tip side.

The core wire 50 is disposed inside the second tube 20. The tip of the core wire 50 is not fixed to the second tube 20 or the inner tube 40. The base end 59 of the core wire 50 is fixed to the inner surface of the tip of the first tube 10. The outer diameter and length of the core wire 50 can be determined arbitrarily. The core wire 50 of this embodiment is formed from a cobalt-chromium alloy. The core wire 50 may be formed from a metal material other than a cobalt-chromium alloy, for example, stainless steel such as SUS304, a nickel-titanium alloy, etc.

Figure 3 is an enlarged view of the connection portion (part B in Figure 1) of the first tube 10 and the second tube 20. Figure 4 is a cross-sectional view of the connection portion of the first tube 10 and the second tube 20. Figure 4(A) illustrates the cross-sectional configuration along line C-C in Figure 3, and Figure 4(B) illustrates the cross-sectional configuration along line D-D in Figure 3. Note that in Figures 3 and 4, the "second region 112" of the first tubular portion 11, which will be described later, is hatched with a grid pattern to distinguish it from other portions. Hereinafter, the configuration of the first tube 10 will be described with reference to Figures 1, 3 and 4.

The first tube 10 is a long member extending along the axis O. The first tube 10 has an opening at each of the tip and base ends, and is a hollow, approximately cylindrical shape with an inner cavity (fluid lumen 10L) that communicates both openings on the inside. The first tube 10 has a first cylindrical portion 11, a tapered portion 12, and a second cylindrical portion 13 from the tip side to the base end side. The first cylindrical portion 11 is a portion provided on the tip side of the first tube 10 and has a first outer diameter Φ11 (FIG. 3). The second cylindrical portion 13 is a portion provided on the base end side of the first tube 10 and has a second outer diameter Φ13 (FIG. 3) larger than the first outer diameter Φ11. The tapered portion 12 is a portion provided between the first cylindrical portion 11 and the second cylindrical portion 13. The outer diameter Φ12 (FIG. 3) of the tapered portion 12 gradually increases from the tip side to the base end side. On the other hand, the first cylindrical portion 11, the tapered portion 12, and the second cylindrical portion 13 each have the same inner diameter Φ10.

In this embodiment, "same" and "equal" do not mean exact agreement, but allow for differences due to manufacturing errors, etc. In this embodiment, the "outer diameter" and "inner diameter" refer to the length of the longest part in any cross section when the cross section of the member (or inner cavity) is elliptical.

The first cylindrical portion 11 of the first tube 10 has, from the tip side to the base end side, a first region 111, a second region 112, and a first region 113. Here, the first region 111, the second region 112, and the first region 113 are regions that are distinguished by the difference in the "surface roughness" of the outer circumferential surface of the first cylindrical portion 11. In this embodiment, the arithmetic mean roughness (Ra) is used as a measure to define the surface roughness. In the catheter 1 of this embodiment, the surface roughness of the second region 112 is greater than the surface roughness of the first region 111 and is greater than the surface roughness of the first region 113. Note that the surface roughness of the first region 111 and the surface roughness of the first region 113 may be the same or different as long as they are both smaller than the second region 112. That is, in the first tube 10 of this embodiment, the outer circumferential surface of the first tubular portion 11 is provided with first regions 111 , 113 at both ends of the second region 112 , each of which is adjacent to the second region 112 .

Figures 5 and 6 are diagrams explaining the surface roughness. Figure 5 (A) shows an example of an enlarged photograph of the first region 111. Figure 5 (B) shows an example of an enlarged photograph of the second region 112. The enlarged photograph shown in Figure 5 is an image obtained by photographing the first region 111 and the second region 112 of the first tube 10 using a laser microscope. Figure 6 (A) shows an example of a measured cross-sectional curve of the first region 111. Figure 6 (B) shows an example of a measured cross-sectional curve of the second region 112. The measured cross-sectional curve shown in Figure 6 is obtained by measuring the first region 111 and the second region 112 of the first tube 10 using a laser microscope. In the measured cross-sectional curve of Figure 6, the horizontal axis plots the evaluation length (μm), and the vertical axis plots the surface height (μm) at each position. Ra was measured using a multiple line roughness meter (VK-250, manufactured by Keyence Corporation). The measurement length (in the length direction of the first tube 10) was 286 μm, and the cutoff value was set to 0.8 μm. In addition, the measurement conditions were set to 18 periphery lines and 4 mm intervals (intervals in an image taken at a magnification of 50 times).

As shown in FIG. 5(A), in the enlarged photograph of the first region 111, the surface (the outer peripheral surface of the first cylindrical portion 11) is smooth with few irregularities. Also, as shown in FIG. 6(A), in the first region 111, there is no significant change in the surface height. The Ra of the first region 111 calculated based on the measured cross-sectional curve shown in FIG. 6(A) was 0.19 (μm). On the other hand, as shown in FIG. 5(B), in the enlarged photograph of the second region 112, the surface (the outer peripheral surface of the first cylindrical portion 11) is uneven with a plurality of approximately circular recesses HE formed thereon. Also, as shown in FIG. 6(B), in the second region 112, high and low surface heights alternate. The Ra of the second region 112 calculated based on the measured cross-sectional curve shown in FIG. 6(B) was 5.28 (μm). Although the first region 113 is not shown, the result is the same as that of the first region 111 shown in FIG. 5(A) and FIG. 6(A). Thus, in the catheter 1 of this embodiment, the surface roughness of the second region 112 is greater than the surface roughness of the first regions 111 and 113. The surface roughness of the tapered portion 12 and the surface roughness of the second tubular portion 13 can be determined arbitrarily. The surface roughness of the second region 112 can be set within a range of 10 to 50 times the surface roughness of the first region 111 (and/or the surface roughness of the first region 113), and can also be set within a range of 20 to 40 times. By setting the surface roughness of the second region 112 within the above range, even if the surface roughness of the second region 112 is made rough to the extent that sufficient bonding strength with the second tube 20 is exerted, it is possible to suppress a sudden decrease in the rigidity of the first tube 10 at the first tubular portion 11 (to achieve a smoother gradual change in rigidity).

Such a first tube 10 can be manufactured, for example, as follows. First, a metal tube having a second outer diameter Φ13 (FIG. 3) and an inner diameter Φ10 (FIG. 3) is prepared. A portion of the tip side of this tube is ground using a centerless processing machine to form the first cylindrical portion 11 and the tapered portion 12. Then, the surface of the first cylindrical portion 11 is laser processed at a substantially central portion in the longitudinal direction to form the second region 112 (recess HE). The first tube 10 is formed of a metal material such as stainless steel such as SUS304, a nickel-titanium alloy, or a cobalt-chromium alloy. That is, the first tube 10 is a metal tube.

3 and 4(B), the thin-diameter portion 23 (base end) of the second tube 20 described above is fixed to the outer circumferential surface of the first tubular portion 11 of the first tube 10. Specifically, the thin-diameter portion 23 (base end) of the second tube 20 is fixed to the second region 112 of the outer circumferential surface of the first tubular portion 11. In the illustrated example, the thin-diameter portion 23 is fixed only to the second region 112, but it is sufficient that the thin-diameter portion 23 is fixed to at least the second region 112, and may be fixed to a part of the first region 111 or the first region 113 in addition to the second region 112. As shown in FIG. 3 and FIG. 4(A), the base end 59 of the core wire 50 described above is fixed to the inner circumferential surface of the first tubular portion 11 of the first tube 10. Specifically, the base end 59 of the core wire 50 is fixed to a region of the inner circumferential surface of the first tubular portion 11 where the first region 111 is formed on the corresponding outer circumferential surface.

Returning to FIG. 1, the explanation will be continued. The connector 70 is a member disposed at the base end 1p of the catheter 1 and held by the surgeon. The connector 70 is hollow, with openings formed at the tip and base ends, and an inner cavity (fluid lumen 70L) that communicates both openings on the inside. The connector 70 has two blade members 71 that the surgeon uses when holding the catheter 1. The blade members 71 can be of any shape. The blade members 71 may be omitted. The connector 70 can be formed of a resin material such as polyamide, polypropylene, polycarbonate, polyacetal, polyethersulfone, etc. The base end 19 of the first tube 10 is fixed to the connector 70, with the fluid lumen 70L and the fluid lumen 10L communicating with each other. The fluid lumen 70L of the connector 70, the fluid lumen 10L of the first tube 10, and the fluid lumen 20L of the second tube 20 function as flow paths for supplying/discharging fluid to/from the space 30L inside the balloon 30.

The above-mentioned components can be fixed to each other by any method, for example, by joining using any bonding agent (e.g., metal solder such as silver solder, gold solder, zinc, Sn-Ag alloy, Au-Sn alloy, etc., or adhesive such as epoxy adhesive) or by welding.

Figure 7 is a diagram illustrating the catheter 1 during delivery. The catheter 1 can be used, for example, as follows. First, the surgeon inserts the guidewire 2 into the patient's blood vessel and delivers the guidewire 2 to the narrowed or blocked part of the blood vessel. The surgeon inserts the base end of the guidewire 2 into the wire lumen 40L from the tip side opening 40a and pulls it out from the port 40b. The surgeon then delivers the catheter 1 along the guidewire 2 to the narrowed or blocked part of the blood vessel. In this way, the catheter 1 is provided with an inner tube 40 connected to the port 40b formed on the side of the second tube 20, so that the catheter 1 can be used as a so-called rapid exchange type catheter, and the guidewire 2 can be quickly inserted into the catheter 1.

Figure 8 is a diagram illustrating the catheter 1 when the balloon 30 is expanded. After delivering the catheter 1 (specifically, the balloon 30) to the narrowed or blocked part of the blood vessel, the surgeon attaches a syringe or the like to the base end of the connector 70 and supplies fluid. The fluid is filled into the space 30L inside the balloon 30 through the fluid lumens 70L, 10L, and 20L. As a result, as shown in Figure 8, the balloon 30 undergoes out-of-plane deformation and expands radially outward, thereby expanding the narrowed or blocked part. In the example of Figure 8, the balloon 30 is expanded with the guide wire 2 removed, but the balloon 30 may be expanded with the guide wire 2 inserted through the wire lumen 40L.

As described above, according to the catheter 1 of the first embodiment, the first metal tube 10 has a first cylindrical portion 11 having a first outer diameter provided at the tip end side and a second cylindrical portion 13 having a second outer diameter larger than the first outer diameter provided at the base end side (FIGS. 1 and 3). Therefore, the tip end side of the first tube 10 can be made more flexible than the base end side, improving safety. In addition, the first metal tube 10 has a tapered portion 12 provided between the first cylindrical portion 11 and the second cylindrical portion 13 (FIGS. 1 and 3). Therefore, compared to the case where the first cylindrical portion 11 and the second cylindrical portion 13 are directly connected, the rigidity of the first tube 10 can be gradually changed, and stress concentration due to a sudden change in rigidity can be suppressed. Furthermore, the base end portion (thin diameter portion 23) of the second resin tube 20 is fixed to the outer circumferential surface of the first cylindrical portion 11, which has the smallest outer diameter of the first metal tube 10 (FIG. 3). Therefore, compared to the case where the second tube 20 is fixed to the second cylindrical portion 13, the rigidity of the shaft body (i.e., the first tube 10 and the second tube 20) can be gradually changed, and stress concentration due to a sudden change in rigidity can be suppressed. As a result, in the catheter 1 in which the shaft body is composed of a plurality of tubes 10, 20 made of different materials, stress concentration at the connection portion of the tubes 10, 20 can be suppressed, and damage to the shaft body due to stress concentration can be suppressed. In addition, since the first cylindrical portion 11 is provided separately from the tapered portion 12 provided for gradual change in rigidity, and the base end portion (thin diameter portion 23) of the second tube 20 is fixed to the outer circumferential surface of this first cylindrical portion 11, a stable and high joint strength between the first tube 10 and the second tube 20 can be obtained compared to the case where the base end portion (thin diameter portion 23) is fixed to the tapered portion 12 (inclined surface).

Here, it is known that the joining strength of a metal and a resin is lower than that of a metal-metal joint or a resin-resin joint. In this regard, according to the catheter 1 of the first embodiment, the outer peripheral surface of the first cylindrical portion 11 of the first tube 10 has a second region 112 having a surface roughness relatively larger than that of the first regions 111 and 113, and the base end portion (thin diameter portion 23) of the second tube 20 is fixed to at least the second region 112 of the outer peripheral surface of the first cylindrical portion 11 (FIG. 3). Therefore, even when the second tube 20 made of resin is joined (fixed) to the first cylindrical portion 11 made of metal and relatively thin in diameter, as in the catheter 1 of the first embodiment, the joining strength between the first tube 10 and the second tube 20 can be suppressed from decreasing. As a result, the catheter 1, in which the shaft body is composed of a plurality of tubes 10 and 20 made of different materials, can suppress the decrease in pressure resistance. Furthermore, by providing a first tubular portion 11 in addition to the tapered portion 12 provided for gradual change in rigidity, and providing a second region 112 with high surface roughness on the outer peripheral surface of this first tubular portion 11, the surface roughness of the second region 112 can be stabilized compared to the case where a region with high surface roughness is provided in the tapered portion 12 (inclined surface), and a sufficiently stable and high joining strength between the first tube 10 and the second tube 20 can be obtained.

The second region 112 has a larger surface roughness than the first regions 111 and 113 (FIGS. 5 and 6). Therefore, the rigidity of the portion of the first tubular portion 11 where the second region 112 is provided is lower than the rigidity of the portion where the first regions 111 and 113 are provided. In this regard, according to the catheter 1 of the first embodiment, the first regions 111 and 113 are provided on both sides of the second region 112, so that the first tubular portion 11 is connected to the tapered portion 12 through the portion where the first region 113 is provided (FIG. 3). Therefore, compared to the case where the first tube 10 is connected to the tapered portion 12 through the portion where the second region 112 is provided, the rigidity of the first tube 10 can be gradually changed, and stress concentration due to a sudden change in rigidity can be suppressed. As a result, damage to the first tube 10 due to stress concentration can be suppressed.

Furthermore, according to the catheter 1 of the first embodiment, the catheter 1 includes a core wire 50 disposed inside the second tube 20, the base end 59 of which is fixed to the tip end of the first tube 10 (Figs. 1 and 3). Therefore, the sudden change in stiffness between the first tube 10 and the second tube 20 can be further alleviated. As a result, damage to the first tube 10 and the second tube 20 due to stress concentration can be further suppressed. In addition, the base end 59 of the core wire 50 is fixed to a region of the inner circumferential surface of the first cylindrical portion 11 in which the first region 111 is formed on the corresponding outer circumferential surface (Fig. 3). Therefore, the outer diameter of the catheter 1 can be reduced. Furthermore, since the core wire 50 is formed of a cobalt-chromium alloy, the sudden change in stiffness between the first tube 10 and the second tube 20 can be further alleviated compared to the case where a stainless steel alloy such as SUS304 is used. As a result, damage to the first tube 10 and the second tube 20 due to stress concentration can be further suppressed.

Furthermore, according to the catheter 1 of the first embodiment, the first tube 10 has the same inner diameter at the tip and the base (FIG. 3: Φ10). In other words, there is no need to reduce the inner diameter of the first tube 10 in order to gradually change the rigidity of the first tube 10. For this reason, for example, when a balloon 30 is provided on the tip side of the second tube 20 and the catheter 1 is configured as a balloon catheter (as in FIG. 1 and FIG. 8), compared to when the inner diameter of the first tube 10 changes according to the outer diameter, it is possible to supply/discharge fluid at a sufficient flow rate through the fluid lumen 10L of the first tube 10, and the inflation/deflation time of the balloon 30 (the time required for the balloon 30 to expand/contract) can be shortened.

Second Embodiment
9 is an enlarged view of the connection portion between the first tube 10A and the second tube 20 of the catheter 1A of the second embodiment. In the second embodiment, an example in which the configuration of the first tubular portion 11A is different will be described. The catheter 1A of the second embodiment includes a first tube 10A instead of the first tube 10 in the configuration described in the first embodiment. The first tube 10A has a first tubular portion 11A instead of the first tubular portion 11. The first tubular portion 11A has a first region 111 and a second region 112 from the distal end side to the proximal end side, and does not have the first region 113 described in the first embodiment. In other words, the first region 111 is located on the distal side of the second region 112 and is adjacent to the second region 112.

In this way, the configuration of the first cylindrical portion 11A can be modified in various ways, and the first region 111 does not have to be provided at both ends of the second region 112 on the outer circumferential surface of the first cylindrical portion 11A. With such a second embodiment, the same effect as the first embodiment described above can be achieved. In addition, according to the catheter 1A of the second embodiment, the first region 111 is located on the distal side of the second region 112 to which the base end portion 59 of the second tube 20 is fixed. Therefore, another member (e.g., the core wire 50 in FIG. 9) arranged inside the second tube 20 can be attached to the region in which the first region 111 is formed on the corresponding outer circumferential surface of the inner or outer circumferential surface of the first cylindrical portion 11A.

Third Embodiment
10 is an enlarged view of a connection portion between the first tube 10B and the second tube 20B of a catheter 1B of a third embodiment. In the third embodiment, an example in which the configuration of the first cylindrical portion 11B is different will be described. The catheter 1B of the third embodiment includes a first tube 10B instead of the first tube 10, a second tube 20B instead of the second tube 20, and a core wire 50B instead of the core wire 50 in the configuration described in the first embodiment.

The first tube 10B has a first cylindrical portion 11B instead of the first cylindrical portion 11. The first cylindrical portion 11B has a second region 112 and a first region 113 from the tip side to the base end side, and does not have the first region 111 described in the first embodiment. In other words, the second region 112 is located closer to the tip side than the first region 113 and is adjacent to the first region 113. The second tube 20B has a thin-diameter portion 23 (base end) fixed to the first region 113 of the outer circumferential surface of the first cylindrical portion 11B. The core wire 50B has a base end 59 fixed to a region of the inner circumferential surface of the first cylindrical portion 11B where the second region 112 is formed on the corresponding outer circumferential surface.

In this way, the configuration of the catheter 1B can be modified in various ways. For example, the second region 112 may be provided at the tip of the first tubular portion 11B, and the second tube 20B may be fixed to the first region 113. Also, the core wire 50B may be fixed to a region of the first tubular portion 11B where the second region 112 is formed on the corresponding outer circumferential surface.

Fourth Embodiment
11 is an enlarged view of a connection portion between the first tube 10C and the second tube 20 of a catheter 1C of the fourth embodiment. In the fourth embodiment, an example in which the configuration of the first cylindrical portion 11C is different will be described. The catheter 1C of the fourth embodiment includes a first tube 10C instead of the first tube 10 and a core wire 50C instead of the core wire 50 in the configuration described in the first embodiment.

The first tube 10C has a first cylindrical portion 11C instead of the first cylindrical portion 11. The first cylindrical portion 11C is entirely the second region 112, and does not have the first regions 111, 113 described in the first embodiment. In this embodiment, the second region 112 is a region that is distinguished by the difference in "surface roughness" from the tapered portion 12. Specifically, in the fourth embodiment, the surface roughness of the second region 112 is greater than the surface roughness of the tapered portion 12. The core wire 50C has a base end 59 fixed to a region of the inner surface of the first cylindrical portion 11C where the second region 112 is formed on the corresponding outer surface.

In this way, the configuration of the catheter 1C can be modified in various ways. For example, the entire first tubular portion 11C may be the second region 112 having a surface roughness greater than that of the tapered portion 12. The core wire 50C may be fixed at any position on the inner circumferential surface of the first tubular portion 11C. This fourth embodiment can also achieve the same effect as the first embodiment described above. In addition, according to the catheter 1C of the fourth embodiment, the second region 112 having a large surface roughness is provided over the entire first tubular portion 11C, which is easily distinguishable due to its small outer diameter. This simplifies the process of fixing the second tube 20C to the first tube 10C.

Fifth Embodiment
12 is an enlarged view of a connection portion between a first tube 10D and a second tube 20D of a catheter 1D of a fifth embodiment. In the fifth embodiment, an example in which the configuration of a first cylindrical portion 11D is different will be described. The catheter 1D of the fifth embodiment includes a first tube 10D instead of the first tube 10 and a second tube 20D instead of the second tube 20 in the configuration described in the first embodiment.

The first tube 10D has a first cylindrical portion 11D instead of the first cylindrical portion 11. The first cylindrical portion 11D has the first region 111 as a whole, and does not have the second region 112 and the first region 113 described in the first embodiment. The surface roughness of the first region 111 of the first cylindrical portion 11D may be the same as or different from the surface roughness of the tapered portion 12. The second tube 20D has a narrow diameter portion 23 (base end) fixed to the first region 111 of the outer circumferential surface of the first cylindrical portion 11D.

In this way, the configuration of the catheter 1D can be modified in various ways. For example, the first tubular portion 11D may not have the second region 112 with a relatively large surface roughness, and may be the first region 111 as a whole. Also, the thin-diameter portion 23 (base end) of the second tube 20D may not be fixed to the second region 112 with a relatively large surface roughness. This fifth embodiment can also achieve the same effects as the first embodiment described above. Furthermore, the catheter 1D of the fifth embodiment can simplify the work of fixing the second tube 20D to the first tube 10D.

Sixth Embodiment
13 is an enlarged view of a connection portion of the first tube 10 and the second tube 20 of a catheter 1E of the sixth embodiment. The catheter 1E of the sixth embodiment does not include a core wire 50 in the configuration described in the first embodiment.

In this way, the configuration of the catheter 1E can be modified in various ways, and it may be configured without the core wire 50 as shown in FIG. 13. It may also be configured without the distal tip 60 described in FIG. 1. When the distal tip 60 is omitted, the distal end 38 of the balloon 30 can be fixed to the distal end of the inner tube 40. This sixth embodiment can also achieve the same effects as the first embodiment described above. Furthermore, according to the catheter 1E of the sixth embodiment, the cost of the catheter 1E can be reduced by omitting some of the components.

Seventh Embodiment
14 is an enlarged view of a connection portion between the first tube 10F and the second tube 20 of a catheter 1F of the seventh embodiment. In the seventh embodiment, an example in which the configuration of the first tube 10F is different will be described. The catheter 1F of the seventh embodiment includes a first tube 10F instead of the first tube 10 in the configuration described in the first embodiment.

The first tube 10F has, from the tip side to the base end side, a first cylindrical portion 11, a tapered portion 12F, and a second cylindrical portion 13F. The configuration of the first cylindrical portion 11 is the same as that of the first embodiment. The second cylindrical portion 13F is a portion provided on the base end side of the first tube 10F. The second cylindrical portion 13F has a second outer diameter Φ13 larger than the first outer diameter Φ11 of the first cylindrical portion 11, and has an inner diameter Φ130 larger than the inner diameter Φ10 of the first cylindrical portion 11. The tapered portion 12F is a portion provided between the first cylindrical portion 11 and the second cylindrical portion 13F. The outer diameter Φ12 of the tapered portion 12F gradually increases from the tip side to the base end side. Similarly, the inner diameter Φ120 of the tapered portion 12F gradually increases from the tip side to the base end side. In this embodiment, the "outer diameter" and "inner diameter" refer to the length of the longest part in any cross section of a member (or inner cavity) that has an elliptical cross section.

In this way, the configuration of the catheter 1F can be modified in various ways. For example, the first tube 10F does not have a substantially constant inner diameter Φ10, and the inner diameter may change in the same way as the outer diameter changes. With this seventh embodiment, the same effect as the first embodiment described above can be achieved. Furthermore, with the catheter 1F of the seventh embodiment, the inner diameter of the fluid lumen 10L can be expanded inside the tapered portion 12F of the first tube 10F and inside the second cylindrical portion 13F, so that a space can be provided inside to place other members.

Eighth Embodiment
15 is an explanatory diagram illustrating the configuration of a catheter 1G of an eighth embodiment. In the eighth embodiment, a case where the catheter 1G is configured as an over-the-wire type catheter will be described. The catheter 1G of the eighth embodiment includes a second tube 20G instead of the second tube 20, an inner tube 40G instead of the inner tube 40, and a connector 70G instead of the connector 70 in the configuration described in the first embodiment.

The second tube 20G does not have a side opening (port 40b) as described in the first embodiment. The inner tube 40G does not have a curved portion 42 as described in the first embodiment, and extends linearly along the axis O inside the balloon 30, the second tube 20G, the first tube 10, and the connector 70G. The distal end 48 of the inner tube 40G is fixed to the distal tip 60. The proximal end 49 of the inner tube 40G is fixed to the connector 70 by a sealing member 77 as described later.

The connector 70G has a branch 72, a first branch 73, a second branch 74, a first wing 75, a second wing 76, and a sealing member 77. The branch 72 is a member composed of two tubular bodies connected in a state where the inner cavities are communicated. Of the branch 72, the branch extending in the X-axis direction is called the first branch 73, and the branch extending in the XY direction is called the second branch 74. The inner cavity 73L of the first branch 73 is provided with the base end 49 of the inner tube 40G and a sealing member 77 for fixing the base end 49 of the inner tube 40G to the inner surface of the first branch 73. The first wing 75 used by the surgeon to grasp the first branch 73 is fixed to the base end of the first branch 73. The surgeon can insert and remove a guide wire into and from the inner tube 40G through an opening 1c provided at the base end of the first wing 75. A second wing 76 is fixed to the base end of the second branch 74, and is used by the surgeon to grasp the second branch 74. The surgeon can supply fluid to the fluid lumens 10L, 20L, 74L for expanding the balloon 30 by attaching a syringe or the like to the opening 1d provided at the base end of the second wing 76. The branch 72, the first branch 73, the second branch 74, the first wing 75, the second wing 76, and the sealing member 77 can be formed from any resin material.

In this way, the configuration of the catheter 1G can be modified in various ways, and the catheter 1G may be configured as an over-the-wire type catheter. With this eighth embodiment, the same effects as those of the first embodiment described above can be achieved.

Ninth embodiment
16 is an explanatory diagram illustrating the configuration of a catheter 1H of a ninth embodiment. In the ninth embodiment, a case in which the configuration of a balloon 30H is different will be described. The catheter 1H of the ninth embodiment includes a balloon 30H instead of the balloon 30 in the configuration described in the first embodiment. The balloon 30H has a tip portion 38 fixed to the outer peripheral surface of the inner tube 40.

In this way, the configuration of the catheter 1H can be modified in various ways, and the balloon 30H may be fixed to the inner tube 40. In addition, in the configuration of Figure 16, the distal tip 60 may be omitted. This ninth embodiment can also achieve the same effects as the first embodiment described above.

Tenth Embodiment
17 is an explanatory diagram illustrating the configuration of a catheter 1I of a tenth embodiment. In the tenth embodiment, a case will be described in which the catheter 1I is configured as a catheter without a balloon. The catheter 1I includes a second tube 20I instead of the second tube 20 in the configuration described in the first embodiment, and does not include a balloon 30.

The second tube 20I has, from the tip side to the base end side, a thin diameter section 25, a tapered section 26, a thick diameter section 21, a tapered section 22, and a thin diameter section 23. The thin diameter section 25 is provided at the most tip side of the second tube 20I, and is a section whose outer diameter and inner diameter are smaller than those of the thick diameter section 21. The tapered section 26 is provided between the thin diameter section 25 and the thick diameter section 21, and is a section whose outer diameter and inner diameter gradually change from the tip side to the base end side. The thick diameter section 21, the tapered section 22, and the thin diameter section 23 are as described in the first embodiment. The thin diameter section 23 (tip section) of the second tube 20I is fixed to the outer circumferential surface of the tip tip 60.

In this way, the configuration of the catheter 1I can be modified in various ways, and it may be configured as a catheter without a balloon 30. In the example of FIG. 17, the catheter 1I is a rapid exchange type catheter. However, the catheter 1I may be an over-the-wire type catheter. In this case, the inner tube 40G described in FIG. 15 may be used instead of the inner tube 40. In the case of an over-the-wire type catheter without a balloon 30, a fluid supply port is not required, and therefore the bifurcated connector 70G is not required. With such a tenth embodiment, the same effects as those of the first embodiment described above can be achieved.

<Modifications of this embodiment>
The present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit and scope of the invention. For example, the following modifications are also possible.

[Modification 1]
In the above first to tenth embodiments, one example of the configuration of the catheters 1, 1A to 1I has been shown. However, the configuration of the catheters 1, 1A to 1I can be modified in various ways. For example, each member of the catheter 1 may be coated on at least one of the inner and outer circumferential surfaces to improve any one of antithrombotic properties, biocompatibility, lubricity, wear resistance, and slidability.

For example, the second tube 20 may be formed by combining multiple tubes. Specifically, for example, the port 40b may be formed by using two tubes having different outer and inner diameters and shifting the joints of the two tubes.

For example, the catheter 1 may have other configurations not described above. Examples of other configurations include a radiopaque marker portion provided on the outer peripheral surface of the inner tube 40 inside the balloon 30. Examples of other configurations include a wire lumen 40L and a second inner tube for forming a separate lumen different from the fluid lumens 10L, 20L, and 70L.

For example, the coil body 402 may not be embedded in the inner tube 40. For example, the core wire 50 may be fixed to the outer peripheral surface of the first tube 10. For example, the core wire 50 may be configured to have a substantially constant outer diameter from the tip to the base end (in other words, a configuration not having a thin-diameter portion 52).

[Modification 2]
The configurations of the catheters 1, 1A to 1I of the first to tenth embodiments and the configurations of the catheters 1, 1A to 1I of the above-mentioned modified examples 1 and 2 may be appropriately combined. For example, in a catheter not provided with the core wire 50 of the sixth embodiment, the configuration of the first cylindrical portions 11A to D described in any of the second to fifth embodiments may be adopted. For example, in a catheter having the first tube 10F of the seventh embodiment, the configuration of the first cylindrical portions 11A to D described in any of the second to fifth embodiments may be adopted. For example, in an over-the-wire type catheter of the eighth embodiment, the configuration of the first cylindrical portions 11A to D described in any of the second to fifth embodiments may be adopted. For example, in a catheter provided with the balloon 30H of the ninth embodiment, the configuration of the first cylindrical portions 11A to D described in any of the second to fifth embodiments may be adopted. For example, in a catheter not provided with the balloon 30 of the tenth embodiment, the configuration of the first cylindrical portions 11A to D described in any of the second to fifth embodiments may be adopted.

Although this aspect has been described above based on embodiments and modified examples, the embodiments of the above-mentioned aspects are intended to facilitate understanding of this aspect and are not intended to limit this aspect. This aspect may be modified or improved without departing from the spirit and scope of the claims, and equivalents are included in this aspect. Furthermore, if a technical feature is not described as essential in this specification, it may be deleted as appropriate.

Reference Signs List 1, 1A to 1I...catheter 1c, 1d...opening 2...guide wire 10, 10A to 10D, 10F...first tube 11, 11A to 11D...first cylindrical portion 12, 12F...tapered portion 13, 13F...second cylindrical portion 20, 20B to 20D, 20G, 20I...second tube 21...large diameter portion 22, 26...tapered portion 23, 25...small diameter portion 30, 30H...balloon 40, 40G...inner tube 40a...tip opening 40b...port 41...main body portion 42...curved portion 50, 50B, 50C...core wire 60...tip tip 70, 70G...connector 71...wing member 72...branched portion 73...first branch 74...second branch 75...first wing portion Reference Signs List 76: second blade portion 77: sealing member 111, 113: first region 112: second region 401: thick portion 402: coil body

Claims (10)

A catheter comprising:
A first tube formed of a metal material;
a second tube connected to a distal end side of the first tube and made of a resin material;
Equipped with
The first tube is
a first cylindrical portion provided at a tip side of the first tube and having a first outer diameter;
a second cylindrical portion provided on a base end side of the first tube and having a second outer diameter larger than the first outer diameter;
a first tapered portion provided between the first cylindrical portion and the second cylindrical portion,
The outer peripheral surface of the first cylindrical portion has a first region and a second region having a surface roughness greater than that of the first region,
In an outer circumferential surface of the first cylindrical portion, the first region is located on a tip side of the second region and is adjacent to the second region,
A catheter, wherein the base end of the second tube is fixed to at least the second region of the outer circumferential surface of the first cylindrical portion of the first tube. 2. The catheter of claim 1 ,
A catheter, wherein the first region is provided adjacent to the second region on both sides of the second region on the outer peripheral surface of the first tubular portion. 2. The catheter of claim 1,
The second tube is
A thin diameter portion provided on a base end side of the second tube;
a large diameter portion provided on a tip side of the second tube and having an outer diameter larger than that of the small diameter portion;
A second tapered portion is provided between the small diameter portion and the large diameter portion,
A catheter, wherein the base end of the second tube is the narrowed portion. The catheter according to any one of claims 1 to 3 , further comprising:
A catheter comprising a core wire disposed inside the second tube and having a proximal end secured to the distal end of the first tube. 5. The catheter of claim 4 ,
A catheter, wherein the base end of the core wire is fixed to a region of the inner circumferential surface of the first tubular portion where the first region is formed on the corresponding outer circumferential surface. The catheter according to claim 4 or claim 5 ,
A catheter, wherein the core wire is formed from a cobalt-chromium alloy. A catheter according to any one of claims 1 to 6 ,
A catheter, wherein the first tube has an equal inner diameter at its tip and base. The catheter according to any one of claims 1 to 7 , further comprising:
an expandable and contractable balloon disposed on the distal end side of the second tube;
an inner tube disposed inside the balloon and the second tube;
A tip tip provided at a tip portion of the inner tube;
Equipped with
A catheter, wherein a distal end of the balloon is fixed to the distal tip or to the outer peripheral surface of the inner tube, and a proximal end of the balloon is fixed to the distal end of the second tube. A catheter comprising:
A first tube formed of a metal material;
a second tube connected to a distal end side of the first tube and made of a resin material;
a core wire disposed inside the second tube and having a proximal end fixed to a distal end of the first tube;
Equipped with
The first tube is
a first cylindrical portion provided at a tip side of the first tube and having a first outer diameter;
a second cylindrical portion provided on a base end side of the first tube and having a second outer diameter larger than the first outer diameter;
a tapered portion provided between the first cylindrical portion and the second cylindrical portion,
A catheter, wherein a base end of the second tube is fixed to an outer peripheral surface of the first cylindrical portion of the first tube. 10. The catheter of claim 9,
A catheter in which the base end of the core wire is fixed to the inner surface of the first cylindrical portion of the first tube, further distal than the portion to which the base end of the second tube is fixed.

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