Catheter

Abstract

To provide a catheter for suppressing the degradation in kink resistance and pressure resistance of the catheter at pitch transition positions of a reinforcing member while also suppressing the degradation in pushability, thereby enabling the pushing force applied from the proximal end to be transmitted to the distal end.SOLUTION: A catheter 60 includes: an elongated shaft part 70 that is introducible into a living body; a resin property varying part, which is provided in a stiffness varying region 85 of the shaft part where the stiffness gradually decreases from the proximal side toward the distal side, and has physical properties of resin varying along the axial direction; and pitch transition positions, which are provided in the stiffness varying region of the shaft part and at which the pitch of a reinforcing member 75 transitions along the axial direction. The resin property varying part and the pitch transition positions are arranged at different locations in the axial direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a catheter. [Background technology]

[0002] Catheter devices have been used for performing treatments in biological lumens. A guidewire having a flexible core wire is used to guide the catheter device to a target site in a biological lumen. For example, transcatheter arterial chemo embolization (TACE) is a treatment method in which a catheter is advanced from the hepatic artery to a location close to a tumor, and an anticancer agent or an embolic substance is injected to selectively necrotize the tumor. In transcatheter arterial chemo embolization, a guidewire is used to advance the catheter.

[0003] In order to guide a catheter to a target site, a technique is widely used in which the catheter is advanced while following a guide wire that has been put in front of it. In addition, a technique is also common in which both the guide wire and the catheter are advanced together using an integrated catheter assembly in which the guide wire is inserted into the catheter.

[0004] A biological lumen has a complex curved or meandering shape. To improve the operability of a catheter when passing through a biological lumen, a catheter is known that is provided with a stiffness varying section in which the stiffness gradually decreases from the base end to the tip end (for example, Patent Document 1 below). The stiffness varying section can be formed by arranging multiple materials with different hardness along the axial direction. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2023-149727 A Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, the rigidity change portion disclosed in Patent Document 1 is composed of a plurality of materials with different hardnesses. Therefore, in the boundary portion between the plurality of materials with different hardnesses, kink resistance and pressure resistance generally decrease.

[0007] On the other hand, the shaft portion of the catheter is provided with a reinforcing body formed by braiding wires. It is preferable that the pitch of this reinforcing body is small at the tip side in order to improve kink resistance and pressure resistance. In contrast, at the base end, a small pitch increases manufacturing time and it is required to increase the pitch from the viewpoint of reducing the amount of wire used. At this time, a pitch change position occurs where the pitch of the reinforcing body changes. The present inventors have found that if this pitch change position coincides with a resin property change portion (a boundary portion between multiple materials with different hardness), the kink resistance and pressure resistance are further reduced.

[0008] The present invention seeks to solve the above-mentioned problems, and aims to provide a catheter that prevents a decrease in the kink resistance and pressure resistance of the catheter at the pitch change position of the reinforcing body, as well as prevents a decrease in pushability and enables the pushing force at the hand to be transmitted to the tip. [Means for solving the problem]

[0009] The above object of the present invention can be achieved by the following means.

[0010] (1) A long shaft portion that can be introduced into a living body; a resin physical property changing portion provided in a rigidity changing region in which the rigidity gradually decreases from the base end side to the tip end side of the shaft portion, the resin physical property changing portion changing along the axial direction; a pitch change position provided in the rigidity change region of the shaft portion, at which the pitch of the reinforcing body changes along the axial direction, A catheter, wherein the resin property change portion and the pitch change position are arranged at different positions in the axial direction.

[0011] (2) The catheter described in (1), having a transition region provided at the pitch change position and transitioning from a first pitch to a second pitch.

[0012] (3) The catheter according to (2), wherein the transition region is formed in a range of 10 to 20 mm along the axial direction.

[0013] (4) The catheter according to any one of (1) to (3), wherein the reinforcing member is configured by an asymmetric braid having a different number of right-handed and left-handed windings. Effect of the Invention

[0014] According to the catheter configured as described above, the resin property change portion and the pitch change position are positioned at different positions in the axial direction, thereby preventing a decrease in the kink resistance and pressure resistance of the catheter at the pitch change position of the reinforcing body, and also preventing a decrease in pushability, making it possible to provide a catheter that can transmit the pushing force from the hand to the tip. [Brief description of the drawings]

[0015] [Figure 1] 1 is a schematic diagram showing a catheter structure including a catheter according to an embodiment of the present invention. FIG. [Diagram 2] 1 is a schematic diagram showing the vicinity of the tip of a shaft portion of a catheter according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a schematic diagram showing the catheter assembly with the catheter hub and guidewire hub disconnected. [Figure 4] FIG. 2 is an enlarged axial cross-sectional view of a tip portion of the catheter structure. [Diagram 5] FIG. 1 is a schematic diagram showing the advancement of an integrated catheter assembly in transarterial chemoembolization. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the attached drawings. Note that the following description does not limit the technical scope or meaning of terms described in the claims. Also, the dimensional ratios in the drawings are exaggerated for the convenience of explanation and may differ from the actual ratios.

[0017] The configuration of a catheter assembly 100 including a catheter 60 according to this embodiment will be described below with reference to Figs. 1 to 5. Fig. 1 is a schematic diagram showing a catheter assembly 100 including a catheter 60 according to an embodiment of the present invention. Fig. 2 is a schematic diagram showing the vicinity of the tip of a shaft portion 70 of the catheter 60 according to this embodiment. Fig. 3 is a schematic diagram showing the catheter assembly 100 in a state in which the catheter hub 110 and the guidewire hub 120 are released from connection. Fig. 4 is an axial cross-sectional view showing an enlarged view of the tip portion of the catheter assembly 100. Fig. 5 is a schematic diagram showing a state in which a catheter 60 is advanced along a guidewire 10 in hepatic arterial chemoembolization.

[0018] In the description of this specification, the longitudinal direction (left-right direction in FIG. 1) in which the shaft portion 70 of the catheter 60 extends is defined as the axial direction, and is indicated by the arrow X in each drawing. The direction perpendicular to the axial direction is defined as the radial direction, and is indicated by the arrow R in FIG. 4. In the catheter assembly 100, the side inserted into the living body (inside the blood vessel) is defined as the distal end side (left side in FIG. 1A), and is indicated by the arrow X1 in each drawing. The side opposite to the distal end side, where the operation is performed by the hand, is defined as the proximal end side (right side in FIG. 1A), and is indicated by the arrow X2 in each drawing. In this specification, the distal end portion means a portion including a certain range in the axial direction from the distal end (the most distal end), and the proximal end portion means a portion including a certain range in the axial direction from the proximal end (the most proximal end). Right-handed means a clockwise direction when the arrow X1 is viewed from the front of the distal end, and left-handed means a counterclockwise direction when the arrow X1 is viewed from the front of the distal end.

[0019] 1 to 4, the catheter assembly 100 comprises a catheter 60 having a shaft portion 70 with a lumen 71, a catheter hub 110 attached to the proximal end of the catheter 60, a guidewire 10 that can be inserted into the lumen 71 of the shaft portion 70, and a guidewire hub 120 that is attached to the proximal end of the guidewire 10 and detachably connected to the catheter hub 110. The catheter 60 has a stiffness changing region 85 whose stiffness gradually decreases from the proximal end side to the distal end side.

[0020] The integrated catheter assembly 100 is inserted into a body lumen and is used to guide both the guidewire 10 and the catheter 60 together to a target site in the body lumen.

[0021] For example, as shown in Fig. 5, trans-arterial chemo-embolization (TACE) is a treatment method in which a catheter 60 is advanced from an artery 91 in a liver 90 to the vicinity of a tumor 92, and an anti-cancer drug or an embolic substance is injected to selectively necrotize the tumor. In trans-arterial chemo-embolization, an integrated catheter assembly 100 is used.

[0022] A biological lumen has a complex curved or meandering shape, and therefore, when the catheter assembly 100 passes through the biological lumen, it needs to have pushability that can efficiently transmit a pushing force to the distal end side.

[0023] The configuration of each part will be described in detail below.

[0024] (Catheter 60) 1, the catheter 60 has a generally circular cross section, an elongated shaft portion 70 that can be introduced into a living body, and a catheter hub 110 that is connected to the base end of the shaft portion 70. The catheter 60 has a kink-resistant protector (strain relief) 115 near the connection between the shaft portion 70 and the catheter hub 110. The catheter 60 is not limited to the form shown in FIG. 1, and may not have the kink-resistant protector 115.

[0025] As shown in Fig. 4, the shaft portion 70 is configured as a flexible tubular member having an inner cavity 71 extending in the axial direction. The length of the shaft portion 70 varies depending on the location, thickness, and other aspects of the blood vessel to which it is applied, but is set to, for example, about 700 mm to 2000 mm, and preferably about 1000 mm to 1500 mm. The outer diameter (thickness) of the shaft portion 70 varies depending on the location, thickness, and other aspects of the blood vessel to which it is applied, but is set to, for example, about 0.4 mm to 3.0 mm, preferably about 0.5 mm to 1.1 mm, and more preferably about 0.80 mm to 1.05 mm. The inner diameter of the shaft portion 70 (outer diameter of the lumen 71) varies depending on the thickness of the guide wire 10 to be inserted, the position and thickness of the blood vessel to which it is applied, and other factors, and is set, for example, at approximately 0.3 mm to 2.3 mm, preferably at approximately 0.4 mm to 0.8 mm, and more preferably at approximately 0.65 mm to 0.75 mm.

[0026] As shown in Fig. 4, the shaft portion 70 has a tubular inner layer 72 and an outer layer 73 arranged to cover the outer surface of the inner layer 72. A contrast portion 74 made of a material having X-ray impermeability is arranged between the inner layer 72 and the outer layer 73 at a part of the distal end of the shaft portion 70. A distal tip may be provided to impart flexibility to the distal end of the shaft portion 70. The shaft portion 70 is provided with a reinforcing member 75 formed by braiding wires on the proximal side of the portion where the contrast portion 74 is formed. The configuration of the reinforcing member 75 will be described later.

[0027] The inner layer 72 is made of a material softer than the guidewire 10 described later, and may be made of resins such as fluorine-containing ethylenic polymers such as PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene-perfluoroalkylvinylether copolymer), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), and ETFE (ethylene-tetrafluoroethylene copolymer), polyamides such as nylon, and polyamide elastomers such as nylon elastomers. Among the above, PTFE (polytetrafluoroethylene) or PFA (tetrafluoroethylene-perfluoroalkylvinylether copolymer), which have high lubricity, may be preferably used. By using these materials, the frictional resistance of the inner surface can be reduced, and therefore the operability of the guidewire 10 inserted into the lumen 71 of the shaft portion 70 during use of the catheter 60 can be improved. As the PTFE (polytetrafluoroethylene), one that has no endothermic peak at 370° C. during the temperature rise process in differential scanning calorimetry (DSC) and has a tensile strength of 350% or more may be used.

[0028] Examples of materials constituting the outer layer 73 include polymer materials such as polyolefins (e.g., polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ionomers, or mixtures of two or more of these), polyvinyl chloride, polyamide, polyester, polyester elastomers, polyamide elastomers, polyurethane, polyurethane elastomers, polyimides, and fluorine-based resins, or mixtures of these materials, and preferably a plurality of polyester elastomers having different hardnesses. The outer layer 73 may have a multi-layer structure formed by laminating different resin materials. It is also possible to form a hydrophilic coating layer having lubricity by coating the outer surface of the outer layer 73 with a material made of a hydrophilic polymer.

[0029] The contrast portion 74 is made of a metal material or a resin material having 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, and is preferably a platinum-iridium alloy. The resin material having X-ray opacity can be made by coating or containing an X-ray contrast material in 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.

[0030] The catheter hub 110 is attached liquid-tight to the base end of the shaft portion 70 by adhesive or a fixing device (not shown). As shown in Fig. 1, the catheter hub 110 has a main body portion 111 having an inner cavity, and a pair of handle portions 112 formed to protrude from the sides of the main body portion 111. The catheter hub 110 functions as an insertion port for the guidewire 10 into the inner cavity 71 of the shaft portion 70, an injection port for contrast medium, medicinal liquid, embolic material, etc. The catheter hub 110 functions as a grip portion when operating the catheter 60. A male thread portion 113 is formed at the base end of the main body portion 111.

[0031] The catheter hub 110 may be made of, for example, a synthetic resin such as polycarbonate, polyolefin, styrene resin, polyamide, or polyester, stainless steel, aluminum, or an aluminum alloy, and preferably is polyamide.

[0032] The anti-kink protector 115 can be made of an elastic material and provided so as to surround a part of the base end of the shaft portion 70. The anti-kink protector 115 can be made of, for example, natural rubber, silicone resin, or the like.

[0033] 1, the catheter 60 has a stiffness change region 85 in which the stiffness gradually decreases from the base end side to the tip end side. By providing the stiffness change region 85 in this manner, the base end side is relatively stiff and the tip end side is relatively soft, thereby improving the operability of the catheter 60 when passing it through a biological lumen.

[0034] In this embodiment, the stiffness changing region 85 gradually decreases the stiffness of the shaft portion 70 of the catheter 60 from the base end side toward the tip end side. As shown in Figures 1 and 2, the stiffness changing region 85 is divided into four regions, a tip portion 81, a first intermediate portion 82, a second intermediate portion 83, and a base portion 84, in that order from the tip end side of the shaft portion 70 toward the base end side.

[0035] The stiffness change region 85 can be formed, for example, by arranging a plurality of materials having different hardnesses along the axial direction. In this 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 toward the tip side (flexibility increases toward the tip side). The hardness of the material constituting the outer layer 73 in the tip portion 81 is lower than the hardness of the material constituting the outer layer 73 in the first intermediate portion 82. The hardness of the material constituting the outer layer 73 in the first intermediate portion 82 is lower than the hardness of the material constituting the outer layer 73 in the second intermediate portion 83. The hardness of the material constituting the outer layer 73 in the second intermediate portion 83 is lower than the hardness of the material constituting the outer layer 73 in the base portion 84. As a result, in the shaft portion 70 of the catheter 60, the tip portion 81 is configured to be more flexible than the first intermediate portion 82, the first intermediate portion 82 is configured to be more flexible than the second intermediate portion 83, and the second intermediate portion 83 is configured to be more flexible than the base portion 84.

[0036] 2, the position at the boundary between tip portion 81 and first intermediate portion 82 where the physical properties of the resin change is defined as a first resin physical property change portion 41. The position at the boundary between first intermediate portion 82 and second intermediate portion 83 where the physical properties of the resin change is defined as a second resin physical property change portion 42. The position at the boundary between second intermediate portion 83 and base portion 84 where the physical properties of the resin change is defined as a third resin physical property change portion 43.

[0037] Examples of hardness of the constituent materials are given below. The hardness is a value measured by a type D durometer conforming to ASTM D2240. The tip portion 81 is located at the most distal end side of the catheter 60 and is therefore the most flexible, and the hardness of the constituent material thereof is preferably 20D to 50D, and more preferably 25D to 45D. The first intermediate portion 82 is the second most flexible after the tip portion 81 and the hardness of the constituent material thereof is preferably 25D to 60D, and more preferably 35D to 55D. The second intermediate portion 83 is the second most flexible after the first intermediate portion 82 and the hardness of the constituent material thereof is preferably 40D to 70D, and more preferably 45D to 65D. The base portion 84 requires a suitable hardness to transmit the operation of the surgeon from the base end side to the distal end side, and the hardness of the constituent material thereof is preferably 50D to 85D, and more preferably 65D to 85D.

[0038] To achieve these hardnesses, the above-mentioned constituent materials are used for the outer layer 73, but a combination of multiple types of these may be used. In addition, additives may be added to the constituent materials to adjust the hardness to an optimal range. The thickness of the outer layer 73 may also be changed to adjust the hardness.

[0039] The distance L1 (see FIG. 2) from the tip of the shaft portion 70 to the first resin physical property change portion 41 is, for example, 82 mm, but is not limited to this. The distance L2 (see FIG. 2) from the tip of the shaft portion 70 to the second resin physical property change portion 42 is, for example, 228 mm, but is not limited to this. The distance L3 (see FIG. 2) from the tip of the shaft portion 70 to the third resin physical property change portion 43 is, for example, 346 mm, but is not limited to this.

[0040] The thickness of the inner layer 72 in the shaft portion 70 is constant over the entire axial length. The thickness of the inner layer 72 is not particularly limited, but is in the range of 0.001 mm to 0.03 mm, for example, 0.015 mm.

[0041] The reinforcing member 75 is preferably configured with an asymmetric braid having a different number of right-handed and left-handed windings. For example, the number of right-handed windings is four, and the number of left-handed windings is eight, but is not limited thereto. By configuring the reinforcing member 75 with an asymmetric braid having a different number of right-handed and left-handed windings in this manner, the amount of metal used can be reduced while the shaft portion 70 can be made flexible, and reachability can be improved. Furthermore, torque transmission is provided, and pressure resistance and kink resistance can be maintained.

[0042] For ease of understanding, in Fig. 2, 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. As shown in Fig. 2, the region 49 in which the reinforcing body 75 is provided has a first region 44 braided at a first pitch, a first transition region 45 transitioning from the first pitch to a second pitch, a second region 46 braided at the second pitch, a second transition region 47 transitioning from the second pitch to a third pitch, and a third region 48 braided at the third pitch.

[0043] The first pitch of the reinforcement 75 in the first region 44 is not particularly limited, but 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, but 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, but is 1.0 mm to 2.0 mm, for example, 1.4 mm. In the first transition region 45, there is a transition from the first pitch of 0.7 mm to the second pitch of 0.9 mm. In the second transition region 47, there is a transition from the second pitch of 0.9 mm to the third pitch of 1.4 mm. The first transition region 45 and the second transition region 47 correspond to pitch change positions where the pitch of the reinforcement 75 changes along the axial direction. The axial length of the first transition region 45 is, for example, more than 0 mm and not more than 150 mm, preferably 5 mm or more and 30 mm or less, and more preferably 10 mm or more and 20 mm or less.

[0044] A distance L4 (see FIG. 2) from the tip of the shaft portion 70 to the base end of the first region 44 is, for example, 173 mm, but is not limited to this. A distance L5 (see FIG. 2) from the tip of the shaft portion 70 to the base end of the first transition region 45 is 170 mm to 210 mm, for example, 183 mm, but is not limited to this. A distance L6 (see FIG. 2) from the tip of the shaft portion 70 to the base end of the second region 46 is 550 mm to 600 mm, for example, 560 mm, but is not limited to this.

[0045] 2, first transition region 45 is disposed at a position different from first resin property change portion 41 and second resin property change portion 42, and second transition region 47 is disposed at a position different from third resin property change portion 43. With this configuration, resin property change portions 41, 42, 43 and the pitch change position (first transition region 45 and second transition region 47) are disposed at different positions in the axial direction, so that even if the pitch of reinforcement body 75 is changed, a decrease in the kink resistance of catheter 60 can be suppressed.

[0046] Furthermore, by providing an area of ​​a predetermined length in the axial direction as the pitch change position, the change in pitch becomes gradual, which makes it possible to suppress a decrease in kink resistance, maintain pressure resistance, and suppress a decrease in pushability.

[0047] (Guidewire 10) As shown in FIG. 3, the base end of the guidewire 10 is attached to the wall of the tip of the guidewire hub 120. The guidewire hub 120 has a main body 121 having an inner cavity and a ring 122 disposed on the tip side of the main body 121. When the main body 121 is injection molded, the base end of the guidewire 10 is inserted. The guidewire hub 120 is used in conjunction with the catheter hub 110 and functions as an inlet for injecting a liquid such as a contrast medium into the inner cavity 71 of the shaft 70. With the guidewire 10 inserted in the inner cavity 71 of the shaft 70, the liquid can be injected or removed. The ring 122 has a female screw (not shown) formed on its inner circumferential surface, which is screwed into the male screw 113 of the catheter hub 110. The ring 122 can rotate relative to the main body 121, but is prevented from slipping out of the main body 121 in the tip direction by engaging with a protrusion (not shown) formed on the outer periphery of the main body 121.

[0048] 1, the tip of guidewire hub 120 is fitted into the lumen of catheter hub 110, and ring portion 122 is rotated to screw male thread portion 113 into female thread portion and tightened with a certain amount of torque. This connects catheter hub 110 and guidewire hub 120 in a liquid-tight manner, and maintains this connected state. Male thread portion 113 and ring portion 122 having a female thread portion constitute a locking means that fixes the connected state of catheter hub 110 and guidewire hub 120.

[0049] The guidewire hub 120 is made of a synthetic resin such as polycarbonate, polyolefin, styrene-based resin, polyamide, polyester, etc. The polyolefin is, for example, polyethylene, polypropylene, or ethylene-propylene copolymer.

[0050] As described above, the catheter 60 according to this embodiment has a long shaft section 70 that can be introduced into a living body, resin property change sections 41, 42, 43 that are provided in a rigidity change region 85 in which the rigidity gradually decreases from the base end side to the tip end side of the shaft section 70 and in which the resin property changes along the axial direction, and pitch change positions (first transition region 45 and second transition region 47) that are provided in the rigidity change region 85 of the shaft section 70 and in which the pitch of the reinforcement body 75 changes along the axial direction, and the resin property change sections 41, 42, 43 and the pitch change positions are arranged at different positions in the axial direction. According to the catheter 60 configured in this manner, the kink resistance and pressure resistance of the catheter 60 are suppressed from decreasing at the pitch change positions of the reinforcement body 75, and the push force at the hand can be transmitted to the tip while suppressing the decrease in pushability.

[0051] Also, it has a first transition region 45 that is provided at the pitch change position and transitions from the first pitch to the second pitch. According to catheter 60 configured in this manner, the change in pitch is gradual, so that it is possible to suppress deterioration in kink resistance and pressure resistance, and to suppress deterioration in pushability.

[0052] In addition, the reinforcing member 75 is an asymmetric braid having a different number of right-handed and left-handed windings, which reduces the amount of metal used while making the shaft portion 70 flexible and improving reach. Furthermore, it has torque transmission properties and can maintain pressure resistance and kink resistance.

[0053] Although the catheter 60 according to the present invention has been described above through an embodiment, the present invention is not limited to the configurations described in the specification, and can be modified as appropriate based on the description of the claims.

[0054] For example, the catheter assembly 100 used in hepatic artery chemoembolization has been given as an example, but it goes without saying that the catheter assembly 100 of the present invention can be used for other procedures, and the catheter 60 may be combined with a different guidewire, with the catheter 60 and the guidewire 10 each having an appropriate length depending on the procedure to be applied.

[0055] In addition, in the above-described embodiment, the reinforcing body 75 is composed of an asymmetric braid having a different number of right-handed and left-handed windings, but it may also be composed of a symmetric braid having the same number of right-handed and left-handed windings, or the number of left-handed windings may be greater.

[0056] The catheter 60 has been described in terms of a configuration in which the hardness of the outer layer 73 in the shaft portion 70 is changed along the axial direction to change the rigidity along the axial direction, but the present invention is not limited to this case. The shaft portion 70 is made of the same material, but the thickness of the material is changed along the axial direction to change the rigidity along the axial direction. For example, the outer layer 73 in the shaft portion 70 has a plurality of regions with different thicknesses along the axial direction, and the thickness of each region can be made smaller toward the tip side (flexibility increases toward the tip side). The rigidity of the catheter 60 can be changed by a combination of both the hardness and thickness of the material. [Explanation of symbols]

[0057] 41 first resin property changing portion, 42 second resin property changing portion, 43 Third resin property change section, 45 first transition region, 47 second transition region, 60 catheters, 70 Shaft section, 75 Reinforcement body, 85 Stiffness change area, 90 Liver,

Claims

1. A long shaft portion that can be introduced into a living body; a resin physical property changing section provided in a rigidity changing region in which the rigidity gradually decreases from the base end side to the tip end side of the shaft section, the resin physical property changing section changing in the axial direction; a pitch change position provided in the rigidity change region of the shaft portion, at which the pitch of the reinforcing body changes along the axial direction, A catheter, wherein the resin property change portion and the pitch change position are arranged at different positions in the axial direction.

2. The catheter of claim 1 , further comprising a transition region at the pitch change location where the pitch transitions from the first pitch to the second pitch.

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

4. The catheter according to claim 1 or 2, wherein the reinforcing member is constituted by an asymmetric braid having a different number of right-handed and left-handed windings.

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