Catheter

Abstract

The present invention provides a catheter capable of suppressing a decrease in kink resistance / pressure resistance of the catheter at a pitch change position of a reinforcing body, and suppressing a decrease in pushing performance, and capable of transmitting a pushing force on a hand side to a tip of the catheter. A catheter (60) is provided with: a long shaft section (70) that can be introduced into a living body; a resin physical property change part which is provided in a rigidity change region (85) in which the rigidity gradually decreases from the base end side to the tip side of the shaft part, and in which the physical properties of the resin change in the axial direction; and a pitch change position provided in the rigidity change region of the shaft portion, the pitch of the reinforcing body (75) being changed in the axial direction, and the resin property change portion and the pitch change position being disposed at different positions in the axial direction.

Description

Technical Field

[0001] The present invention relates to catheters. Background Art

[0002] In the past, catheter devices were used to perform treatments in the lumen of a living body. In order to guide the catheter device to the target site in the lumen of a living body, a guide wire with a flexible core wire was used. For example, transcatheter arterial chemoembolization (TACE) is a treatment method that pushes a catheter from the artery of the liver to the vicinity of the tumor, injects anticancer agents and embolic substances, and selectively necrotizes the tumor. In this transcatheter arterial chemoembolization, a guide wire is used to push the catheter.

[0003] When guiding a catheter to a target site, a technique of advancing the catheter following a guide wire that has been advanced is widely used. In addition, a technique of advancing both the guide wire and the catheter together using an integrally constructed catheter assembly in which the guide wire is inserted into the catheter is also commonly used.

[0004] A biological lumen has a complex curved or serpentine shape. It is known that a catheter is provided with a rigidity changing portion whose rigidity gradually decreases from the base end side to the front end side in order to improve the operability of the catheter when passing through the biological lumen (for example, the following patent document 1). The rigidity changing portion can be formed by arranging a plurality of materials with different hardnesses along the axial direction.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2023-149727 Summary of the invention

[0008] Problems to be solved by the invention

[0009] As described above, the rigidity changing portion disclosed in Patent Document 1 is composed of a plurality of materials having different hardnesses. Therefore, the kink resistance and pressure resistance are generally reduced at the boundary portion of the plurality of materials having different hardnesses.

[0010] On the other hand, a reinforcement body formed by weaving wires is provided on the shaft of the catheter. In order to improve the kink resistance / pressure resistance, it is preferred that the reinforcement body reduce the spacing on the front end side. In contrast, at the base end, if the spacing is small, it will take up manufacturing time. In addition, from the perspective of reducing the usage fee of the wires, it is required to increase the spacing. At this time, a spacing change position where the spacing of the reinforcement body is changed will occur. In addition, the inventors of the present application have found that if the spacing change position coincides with the resin property change portion (the boundary portion of multiple materials with different hardness), the kink resistance / pressure resistance is further reduced.

[0011] The present invention solves the above problems and aims to provide a catheter which can suppress the reduction of the kink resistance and pressure resistance of the catheter at the pitch change position of the reinforcement body and can transmit the pushing force at hand to the front end while suppressing the reduction of the pushability.

[0012] Means for solving problems

[0013] The above-mentioned object of the present invention is achieved by the following means.

[0014] (1) A catheter comprising:

[0015] An elongated shaft portion capable of being introduced into a living body;

[0016] a resin property changing portion provided in a rigidity changing region where the rigidity gradually decreases from the base end side toward the front end side of the shaft portion, and the physical property of the resin changes along the axial direction; and

[0017] A spacing change position is provided in the rigidity change region of the shaft portion, and the spacing of the reinforcing bodies changes along the axial direction.

[0018] The resin property changing portion and the pitch changing position are arranged at different positions in the axial direction.

[0019] (2) The catheter according to (1), wherein

[0020] A transition area is provided, which is arranged at the pitch change position and transitions from the first pitch to the second pitch.

[0021] (3) The catheter according to (2), wherein:

[0022] The transition region is formed within a range of 10 to 20 mm along the axial direction.

[0023] (4) The catheter according to any one of (1) to (3), wherein:

[0024] The reinforcement body is composed of an asymmetric braid having different numbers of right-handed and left-handed roots.

[0025] Effects of the Invention

[0026] According to the catheter constructed in the above manner, since the resin property change portion and the pitch change position are arranged at different positions in the axial direction, the reduction in the kink resistance and pressure resistance of the catheter can be suppressed at the pitch change position of the reinforcement body, and the reduction in the pushing performance can be suppressed so that the pushing force at hand can be transmitted to the front end. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram showing a catheter structure including a catheter according to an embodiment of the present invention.

[0028] Figure 2 This is a schematic diagram showing the vicinity of the distal end of the shaft portion of the catheter according to the present embodiment.

[0029] Figure 3 This is a schematic diagram showing the catheter assembly in a state where the connection between the catheter hub and the guidewire hub is released.

[0030] Figure 4 It is an axial cross-sectional view showing an enlarged front end portion of the catheter structure.

[0031] Figure 5 This is a diagram schematically showing a state in which a catheter assembly of an integral structure is advanced during transcatheter arterial chemoembolization.

[0032] Description of Reference Numerals

[0033] 41 Section 1 Resin Property Changes

[0034] 42 Section 2 Resin Property Changes

[0035] 433rd Resin Property Change Section

[0036] 451st Transition Area

[0037] 47 Transition Zone 2

[0038] 60 catheter

[0039] 70 shaft

[0040] 75 Strengthening body

[0041] 85 Rigidity Change Area

[0042] 90 Liver DETAILED DESCRIPTION

[0043] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that the following description does not limit the technical scope and meaning of the terms described in the claims. In addition, for the sake of convenience of description, the dimensional ratios of the drawings are sometimes exaggerated and different from the actual ratios.

[0044] Below, refer to Figure 1 to Figure 5 The configuration of a catheter assembly 100 including the catheter 60 according to the present embodiment will be described. Figure 1 1 is a schematic diagram showing a catheter assembly 100 including a catheter 60 according to an embodiment of the present invention. Figure 2 1 is a schematic diagram showing the vicinity of the distal end of the shaft portion 70 of the catheter 60 according to the present embodiment. Figure 3 This is a schematic diagram showing the catheter assembly 100 in a state where the connection between the catheter hub 110 and the guidewire hub 120 is released. Figure 4 It is an axial cross-sectional view showing an enlarged front end portion of the catheter assembly 100 . Figure 5 The diagram schematically shows a state where a catheter 60 is advanced along a guide wire 10 during transcatheter arterial chemoembolization.

[0045] In the description of this specification, the longitudinal direction in which the shaft portion 70 of the catheter 60 extends ( Figure 1 The left and right directions in the figure are defined as the axial direction, which is indicated by arrow X in each figure. The direction perpendicular to the axial direction is defined as the radial direction. Figure 4 In the catheter assembly 100, the side inserted into the living body (inside the blood vessel) is defined as the front end side ( Figure 1 The left side in the figure is indicated by arrow X1 in each figure, and the side operated by hand on the opposite side of the front end side is defined as the base end side ( Figure 1 In the present specification, the front end portion refers to a portion including a certain range in the axial direction from the front end (the most front end), and the base end portion refers to a portion including a certain range in the axial direction from the base end (the most base end). Right-handed rotation is the clockwise direction when the arrow X1 is viewed from the front of the most front end, and left-handed rotation is the counterclockwise direction when the arrow X1 is viewed from the front of the most front end.

[0046] like Figure 1 to Figure 4 As shown, the catheter assembly 100 includes: a catheter 60 having a shaft 70 with an inner cavity 71; a catheter hub 110 mounted on the base end of the catheter 60; a guide wire 10 that can be inserted into the inner cavity 71 of the shaft 70; and a guide wire hub 120 mounted on the base end of the guide wire 10 and detachably connected to the catheter hub 110. The catheter 60 has a rigidity change region 85 in which the rigidity gradually decreases from the base end side toward the front end side.

[0047] The integrated catheter assembly 100 is inserted into a lumen of a living body to guide both the guide wire 10 and the catheter 60 to a target site in the lumen of the living body.

[0048] For example, Figure 5 As shown, transcatheter arterial chemoembolization (TACE) is a treatment method in which a catheter 60 is advanced from an artery 91 of a liver 90 to the vicinity of a tumor 92 and an anticancer agent or embolic material is injected to selectively necrotize the tumor. In this transcatheter arterial chemoembolization, an integral catheter assembly 100 is used.

[0049] The lumen of a living body has a complex curved or meandering shape. Therefore, when the catheter assembly 100 passes through the lumen of a living body, pushability is required to efficiently transmit the pushing force to the distal end side.

[0050] The configuration of each part will be described in detail below.

[0051] (Conduit 60)

[0052] like Figure 1 As shown in FIG. 1 , the catheter 60 includes: a long shaft 70 having a substantially circular cross section and capable of being introduced into a living body; and a catheter hub 110 connected to the base end of the shaft 70. The catheter 60 includes an anti-kink protection portion (strain relief portion) 115 near the connection portion where the shaft 70 and the catheter hub 110 are connected. It should be noted that the catheter 60 is not limited to Figure 1 The method may not include the anti-kink protection portion 115.

[0053] The shaft portion 70 is Figure 4 As shown, the shaft 70 is a flexible tubular member having an inner cavity 71 extending in the axial direction. The length of the shaft 70 varies depending on the position and thickness of the blood vessel to be used, but is preferably set to about 700 mm to 2000 mm, and preferably about 1000 mm to 1500 mm. The outer diameter (thickness) of the shaft 70 varies depending on the position and thickness of the blood vessel to be used, and is preferably set to about 0.4 mm to 3.0 mm, and preferably about 0.5 mm to 1.1 mm, and more preferably about 0.80 mm to 1.05 mm. As for the inner diameter of the shaft 70 (the outer diameter of the inner cavity 71), the preferred value varies depending on the thickness of the inserted guide wire 10, the location and thickness of the applied blood vessel, and other cases. For example, it is set to about 0.3mm to 2.3mm, preferably about 0.4mm to 0.8mm, and more preferably about 0.65mm to 0.75mm.

[0054] like Figure 4 As shown, the shaft portion 70 has a tubular inner layer 72 and an outer layer 73 arranged in a manner to cover the outer surface of the inner layer 72. A contrast portion 74 is arranged at a portion of the front end portion of the shaft portion 70, and is formed between the inner layer 72 and the outer layer 73 by a material having X-ray opacity. It should be noted that a front end tip for adding flexibility may also be provided at the front end of the shaft portion 70. The shaft portion 70 is provided with a reinforcing body 75 formed by braiding a wire material at a base end side of the portion where the contrast portion 74 is formed. The structure of the reinforcing body 75 will be described later.

[0055] The constituent material of the inner layer 72 is formed by a material softer than the guide wire 10 described later, for example, PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), ETFE (ethylene-tetrafluoroethylene copolymer) and other fluorine-containing ethylene polymers, polyamides such as nylon, nylon elastomers and other polyamide elastomers and other resins can be used. Among them, PTFE (polytetrafluoroethylene) or PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) with high lubricity can also be preferably used. By using these materials, the friction resistance of the inner surface can be reduced, so when using the catheter 60, the operability of the guide wire 10 inserted into the inner cavity 71 of the shaft 70 can be improved. As PTFE (polytetrafluoroethylene), a material having no endothermic peak at 370°C and a tensile strength of more than 350% can be used during the temperature rise process of differential scanning calorimetry (DSC).

[0056] As the constituent material of the outer layer 73, for example, there can be cited polymer materials such as polyolefins (e.g., polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ionomers, or mixtures of two or more thereof), polyvinyl chloride, polyamide, polyester, polyester elastomer, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, fluororesin, or mixtures thereof, preferably a plurality of polyester elastomers of different hardness. The outer layer 73 may also have a multilayer structure formed by stacking different resin materials. In addition, the outer surface of the outer layer 73 may be coated with a material formed by a hydrophilic polymer to form a hydrophilic coating having lubricity.

[0057] The contrast portion 74 is made of a metal material or a resin material having a higher X-ray opacity than the inner layer 72 and the outer layer 73. The metal material having X-ray opacity can be made of, for example, platinum, gold, silver, tungsten or an alloy thereof, preferably a platinum-iridium alloy. In addition, the resin material having X-ray opacity can be made by coating / containing an X-ray contrast material with a resin material that does not have X-ray opacity. Examples of the X-ray contrast material include powdered inorganic materials such as tungsten, barium sulfate, and bismuth oxide.

[0058] The catheter hub 110 is attached to the base end of the shaft portion 70 in a liquid-tight manner by means of an adhesive, a fixing member (not shown), or the like. Figure 1 As shown, the catheter hub 110 includes a main body 111 having an inner cavity and a pair of handles 112 formed to protrude from the side of the main body 111. The catheter hub 110 functions as an insertion port for the guide wire 10 into the inner cavity 71 of the shaft 70 and an injection port for contrast media, liquid medicine, embolic substances, etc. The catheter hub 110 functions as a gripping portion when operating the catheter 60. An external thread portion 113 is formed at the base end of the main body 111.

[0059] The catheter hub 110 is made of, for example, synthetic resins such as polycarbonate, polyolefin, styrene-based resin, polyamide, polyester, stainless steel, aluminum, and aluminum alloy, preferably polyamide.

[0060] The anti-kink protection portion 115 can be formed of an elastic material provided so as to surround a portion of the base end portion of the shaft portion 70. As a constituent material of the anti-kink protection portion 115, for example, natural rubber, silicone resin, or the like can be used.

[0061] like Figure 1 As shown, the catheter 60 has a rigidity change region 85 whose rigidity gradually decreases from the base end side toward the front end side. By providing the rigidity change region 85 in this way, the base end side is harder and the front end side is softer, so the operability when passing the catheter 60 through the body lumen can be improved.

[0062] In this embodiment, the rigidity changing region 85 gradually reduces the rigidity of the shaft portion 70 of the catheter 60 from the base end side toward the front end side. Figure 1 , Figure 2 As shown, the rigidity varying region 85 is divided into four regions, namely, a distal end portion 81 , a first intermediate portion 82 , a second intermediate portion 83 , and a proximal portion 84 , in order from the distal end side to the proximal end side of the shaft portion 70 .

[0063] The rigidity change region 85 can be formed, for example, by arranging a plurality of materials having different hardnesses along the axial direction. In the present embodiment, the outer layer 73 in the shaft portion 70 has a plurality of regions having different hardnesses along the axial direction, and the hardness of the material constituting each region decreases as it approaches the front end side (the softness increases as it approaches the front end side). The hardness of the material constituting the outer layer 73 at the front end portion 81 is lower than the hardness of the material constituting the outer layer 73 at the first intermediate portion 82. The hardness of the material constituting the outer layer 73 at the first intermediate portion 82 is lower than the hardness of the material constituting the outer layer 73 at the second intermediate portion 83. The hardness of the material constituting the outer layer 73 at the second intermediate portion 83 is lower than the hardness of the material constituting the outer layer 73 at the base portion 84. Thus, in the shaft portion 70 of the catheter 60, the front end portion 81 is configured to be softer than the first intermediate portion 82, the first intermediate portion 82 is softer than the second intermediate portion 83, and the second intermediate portion 83 is softer than the base portion 84.

[0064] In this manual, Figure 2 As shown, the boundary between the front end portion 81 and the first intermediate portion 82 and the position where the physical property of the resin changes is defined as the first resin physical property change portion 41. The boundary between the first intermediate portion 82 and the second intermediate portion 83 and the position where the physical property of the resin changes is defined as the second resin physical property change portion 42. The boundary between the second intermediate portion 83 and the base portion 84 and the position where the physical property of the resin changes is defined as the third resin physical property change portion 43.

[0065] Here is an example of the hardness of the constituent material. The hardness is a value measured by a D-type hardness meter based on ASTM D2240. The front end portion 81 is the softest because it is located at the front end side of the catheter 60. The hardness of the constituent material is preferably 20D to 50D, and more preferably 25D to 45D. The first intermediate portion 82 is harder than the front end portion 81. The hardness of the constituent material is preferably 25D to 60D, and more preferably 35D to 55D. The second intermediate portion 83 is harder than the first intermediate portion 82. The hardness of the constituent material is preferably 40D to 70D, and more preferably 45D to 65D. The base portion 84 requires appropriate hardness in order to transmit the operator's operation from the base end side to the front end side. The hardness of the constituent material is preferably 50D to 85D, and more preferably 65D to 85D.

[0066] In order to achieve the above hardness, the outer layer 73 uses the above-mentioned constituent materials, but it can also be combined with multiple materials. In addition, in order to adjust the hardness to the optimal range, additives can also be added to the constituent materials. In order to adjust the hardness, the wall thickness of the outer layer 73 can also be changed.

[0067] The distance L1 from the front end of the shaft portion 70 to the first resin property change portion 41 (see Figure 2 ) is, for example, 82 mm, but is not limited thereto. The distance L2 from the front end of the shaft portion 70 to the second resin property change portion 42 (see Figure 2 ) is, for example, 228 mm, but is not limited thereto. The distance L3 from the front end of the shaft portion 70 to the third resin property change portion 43 (see Figure 2 ) is, for example, 346 mm, but is not limited to this.

[0068] The thickness of the inner layer 72 in the shaft portion 70 is set constant over the entire length in the axial direction. The thickness of the inner layer 72 is not particularly limited, but is 0.001 mm to 0.03 mm, for example, 0.015 mm.

[0069] The reinforcing body 75 is preferably formed of an asymmetric braid having different numbers of right-handed and left-handed roots. The number of right-handed roots is, for example, 4, and the number of left-handed roots is, for example, 8, but it is not limited thereto. In this way, the reinforcing body 75 is formed of an asymmetric braid having different numbers of right-handed and left-handed roots, thereby reducing the amount of metal used and making the shaft 70 soft and improving reachability. In addition, it has torque transmission performance and can maintain pressure resistance and kink resistance.

[0070] For ease of understanding, Figure 2 In the embodiment, the shaft portion 70 is shown on the upper side of the catheter 60, and the outer layer 73 is shown on the lower side. The region 49 provided with the reinforcement body 75 is shown in FIG. Figure 2As shown, there is a first region 44 woven at a first pitch, a first transition region 45 transitioning from the first pitch to a second pitch, a second region 46 woven at a second pitch, a second transition region 47 transitioning from the second pitch to a third pitch, and a third region 48 woven at a third pitch.

[0071] The first pitch of the reinforcement 75 in the first region 44 is not particularly limited, and is 0.4 mm to 0.8 mm, for example, 0.7 mm. The second pitch of the reinforcement 75 in the second region 46 is not particularly limited, and is 0.7 mm to 1.2 mm, for example, 0.9 mm. The third pitch of the reinforcement 75 in the third region 48 is not particularly limited, and is 1.0 mm to 2.0 mm, for example, 1.4 mm. In the first transition region 45, the first pitch of 0.7 mm transitions to the second pitch of 0.9 mm. In the second transition region 47, the second pitch of 0.9 mm transitions to the third pitch of 1.4 mm. The first transition region 45 and the second transition region 47 correspond to the pitch change position where the pitch of the reinforcement 75 changes along the axial direction. The length of the first transition region 45 in the axial direction is, for example, more than 0 mm and less than 150 mm, preferably more than 5 mm and less than 30 mm, and more preferably more than 10 mm and less than 20 mm.

[0072] The distance L4 from the most distal end of the shaft portion 70 to the proximal end of the first region 44 (see Figure 2 ) is, for example, 173 mm, but is not limited thereto. The distance L5 from the front end of the shaft portion 70 to the base end of the first transition region 45 (see Figure 2 ) is 170 mm to 210 mm, for example, 183 mm, but is not limited thereto. The distance L6 from the front end of the shaft portion 70 to the base end of the second region 46 (see Figure 2 ) is 550mm~600mm, for example, 560mm, but not limited to this.

[0073] As mentioned above, Figure 2 As shown in FIG. 1 , the first transition region 45 is arranged at a position different from the first resin property change portion 41 and the second resin property change portion 42, and the second transition region 47 is arranged at a position different from the third resin property change portion 43. According to this configuration, since the resin property change portions 41, 42, 43 and the pitch change positions (the first transition region 45 and the second transition region 47) are arranged at different positions in the axial direction, even if the pitch of the reinforcement body 75 is changed, the kink resistance of the conduit 60 can be suppressed from being reduced.

[0074] Furthermore, by providing a region of a predetermined length in the axial direction as the pitch changing position, the pitch can be changed smoothly, thereby suppressing a decrease in kink resistance, maintaining pressure resistance, or suppressing a decrease in pushability.

[0075] (Guide wire 10)

[0076] like Figure 3 As shown, the base end of the guide wire 10 is mounted on the front end wall of the guide wire hub 120. The guide wire hub 120 includes a main body 121 having an inner cavity and a ring portion 122 arranged on the front end side of the main body 121. When the main body 121 is injection molded, the base end of the guide wire 10 is inserted. The guide wire hub 120 is used in conjunction with the catheter hub 110, and functions as an injection port for injecting liquid such as contrast agent into the inner cavity 71 of the shaft 70. While the guide wire 10 is inserted into the inner cavity 71 of the shaft 70, the liquid can be injected or extracted. The ring portion 122 has an internal thread portion (not shown) formed on the inner circumferential surface into which the external thread portion 113 of the catheter hub 110 is screwed. The ring portion 122 can rotate relative to the main body 121, but is restricted from coming out of the main body 121 toward the front end direction by engaging with a convex portion (not shown) formed on the outer circumference of the main body 121.

[0077] like Figure 1 As shown, the front end of the guidewire hub 120 is embedded in the inner cavity of the catheter hub 110, and the ring portion 122 is rotated to screw the external thread portion 113 and the internal thread portion, and tightened with a certain degree of torque. As a result, the catheter hub 110 and the guidewire hub 120 are liquid-tightly connected and the connection state is maintained. The locking mechanism that fixes the connection state of the catheter hub 110 and the guidewire hub 120 is composed of the external thread portion 113 and the ring portion 122 with the internal thread portion.

[0078] The guidewire hub 120 is made of a synthetic resin such as polycarbonate, polyolefin, styrene resin, polyamide, polyester, etc. Examples of polyolefin include polyethylene, polypropylene, and ethylene-propylene copolymer.

[0079] As described above, the catheter 60 of this embodiment includes: the elongated shaft 70 that can be introduced into a living body; the resin property changing parts 41, 42, 43 that are provided in the rigidity changing region 85 where the rigidity gradually decreases from the base end side toward the front end side of the shaft 70, and the physical properties of the resin change along the axial direction; and the pitch changing positions (the first transition region 45 and the second transition region 47) that are provided in the rigidity changing region 85 of the shaft 70, and the pitch of the reinforcement 75 changes along the axial direction, and the resin property changing parts 41, 42, 43 and the pitch changing positions are arranged at different positions in the axial direction. According to the catheter 60 configured in this way, it is possible to suppress the reduction of the kink resistance / pressure resistance of the catheter 60 at the pitch changing position of the reinforcement 75, and suppress the reduction of the pushability and transmit the push force at hand to the front end.

[0080] In addition, the first transition region 45 is provided at the pitch change position and transitions from the first pitch to the second pitch. According to the catheter 60 configured in this way, the pitch change becomes smooth, so it is possible to suppress the decrease in kink resistance and pressure resistance or the decrease in pushability.

[0081] In addition, the reinforcement body 75 is formed of an asymmetric braid with different numbers of right-hand and left-hand threads, which can reduce the amount of metal used and make the shaft 70 flexible, thereby improving reachability. In addition, it has torque transmission properties and can maintain pressure resistance and kink resistance.

[0082] As mentioned above, the catheter 60 of the present invention has been described based on the embodiment, but the present invention is not limited to the respective configurations described in the specification, and can be modified appropriately based on the description of the claims.

[0083] For example, the example of the catheter assembly 100 used in hepatic arterial chemoembolization is given, but the catheter assembly 100 of the present invention can of course be used in other techniques, and the catheter 60 can also be combined with other guide wires, and the catheter 60 and the guide wire 10 each have an appropriate length corresponding to the applied technique.

[0084] In the above embodiment, the reinforcing body 75 is formed of an asymmetric braid having different numbers of right and left twists, but may be formed of a symmetric braid having the same number of right and left twists, or may have more left twists.

[0085] Regarding the catheter 60, a method of changing the rigidity along the axial direction by changing the hardness of the outer layer 73 in the shaft portion 70 along the axial direction has been described, but the present invention is not limited to this case. The rigidity can be changed along the axial direction by forming the shaft portion 70 from the same material and changing the wall thickness of the material along the axial direction. For example, the outer layer 73 in the shaft portion 70 has a plurality of regions with different wall thicknesses along the axial direction, and the wall thickness constituting each region can be reduced as it approaches the front end side (flexibility increases as it approaches the front end side). The rigidity of the catheter 60 can be changed by a combination of the hardness of the material and the wall thickness.

Claims

1. A catheter, characterized in that: have: An elongated shaft portion capable of being introduced into a living body; a resin property changing portion provided in a rigidity changing region where the rigidity gradually decreases from the base end side toward the front end side of the shaft portion, and the physical property of the resin changes along the axial direction; and A spacing change position is provided in the rigidity change region of the shaft portion, and the spacing of the reinforcing bodies changes along the axial direction. The resin property changing portion and the pitch changing position are arranged at different positions in the axial direction.

2. The catheter according to claim 1, characterized in that A transition area is provided, which is arranged at the pitch change position and transitions from the first pitch to the second pitch.

3. The catheter according to claim 2, characterized in that The transition region is formed within a range of 10 to 20 mm along the axial direction.

4. The catheter according to claim 1 or 2, characterized in that The reinforcement body is composed of an asymmetric braid having different numbers of right-handed and left-handed roots.

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