catheter

Abstract

The present invention provides a catheter that can suppress significant deformation of the tip of the hollow shaft within the body, even if excessive force is applied to the hollow shaft by manipulating the gripping member during the procedure. [Solution] The catheter 1 comprises a hollow shaft 11 having a proximal end B1 including the proximal end, and a tip A1 extending from the tip of the proximal end B1 toward the tip, wherein the rigidity of the proximal end B1 is less than the rigidity of the tip A1.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a catheter. BACKGROUND ART

[0002] As a medical instrument for performing treatment while being inserted into a body cavity such as a blood vessel, for example, a catheter is known.

[0003] A catheter is inserted into a complexly curved body cavity. For this reason, in general, the distal end portion of the catheter is formed flexibly so as to follow the body cavity, and the proximal end portion is formed rigidly to enhance pushability (see, for example, Patent Document 1). PRIOR ART DOCUMENTS PATENT DOCUMENTS

[0004] PATENT DOCUMENT 1 Japanese Unexamined Patent Application Publication No. 2021-10685 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] When operating the catheter, the operator rotates or pushes the catheter while gripping a gripping member provided at the proximal end of the catheter. At this time, the operation of the hollow shaft by the operator may cause the distal end portion of the hollow shaft to be significantly deformed inside the body. MEANS FOR SOLVING THE PROBLEMS

[0006] The catheter of the present disclosure includes a hollow shaft having a proximal end portion including a proximal end, and a distal end portion extending from the distal end of the proximal end portion toward the distal end side to the distal end, wherein the rigidity of the proximal end portion is lower than the rigidity of the distal end portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] [Figure 1] It is a schematic cross-sectional view showing the first embodiment. [Figure 2] This is a schematic diagram illustrating a method for measuring bending stiffness. [Figure 3] This is a schematic cross-sectional view showing a second embodiment. [Figure 4] This is a schematic cross-sectional view taken along the line IV-IV in Figure 3. [Figure 5] This is a schematic cross-sectional view showing a third embodiment. [Figure 6] This is a schematic cross-sectional view taken along the line VI-VI in Figure 5. [Figure 7] This is a schematic cross-sectional view showing a fourth embodiment. [Figure 8] This is a schematic cross-sectional view showing an enlarged portion of Figure 7. [Figure 9] This is a partially enlarged schematic cross-sectional view showing one form of a hollow shaft. [Figure 10] This is a partially enlarged schematic cross-sectional view showing one form of a hollow shaft. [Modes for carrying out the invention]

[0008] The catheter described herein is (1) A hollow shaft having a base portion including a proximal end and a tip portion extending from the tip of the proximal end toward the tip, wherein the rigidity of the proximal end is less than the rigidity of the tip portion. With this configuration, for example, even if excessive force is applied to the hollow shaft by manipulating the gripping member during a procedure, the less rigid base end will deform before the tip. This allows the practitioner to detect the abnormality early and, for example, quickly stop the procedure. As a result, it is possible to suppress significant deformation of the tip of the hollow shaft inserted into the body.

[0009] (2) In the catheter described in (1) above, The hollow shaft may have a reinforcing body formed by element wires, and the reinforcing body may be embedded in the hollow shaft from the distal end portion to the proximal end portion along the longitudinal direction of the hollow shaft, and the pitch of the element wires of the reinforcing body located at the proximal end portion may be larger than the pitch of the element wires of the reinforcing body located at the distal end portion. According to this configuration, by changing the pitch of the element wires, the proximal end portion can be formed to have lower rigidity than the distal end portion.

[0010] (3) In the catheter according to the above (1) and (2), The distal end portion and the proximal end portion may each be formed of a resin material. According to this configuration, the hollow shaft can be easily formed.

[0011] (4) In the catheter according to the above (3), The resin material of the distal end portion may include a first resin material, and the resin material of the proximal end portion may include the first resin material and a second resin material that is different from the first resin material and has lower rigidity than the first resin material. According to this configuration, the rigidity of the hollow shaft can be easily adjusted, and the rigidity of the proximal end portion can be effectively reduced compared to the distal end portion.

[0012] (5) In the catheter according to the above (4), The proximal end portion may have an inner layer formed of the second resin material, and an outer layer disposed so as to cover the outer periphery of the inner layer and formed of the first resin material. According to this configuration, the surface of the proximal end portion can be hardened.

[0013] (6) In the catheter according to the above (4), The proximal end portion may have an inner layer formed of the first resin material, and an outer layer disposed so as to cover the outer periphery of the inner layer and formed of the second resin material. According to this configuration, the surface of the proximal end portion can be made flexible. (7) In the catheter according to any one of (4) to (6) above, The first resin material at the distal end portion and the first resin material at the proximal end portion may be integrally formed. According to this configuration, it is possible to effectively prevent the hollow shaft from breaking at the boundary between the distal end portion and the proximal end portion.

[0014] (8) In the catheter according to any one of (1) to (7) above, The proximal end portion may be a region within 100 mm from the proximal end of the hollow shaft toward the distal end side. According to this configuration, the portion with low rigidity in the hollow shaft can be set to an appropriate length. As a result, the pushability and torque transmission performance of the catheter can be improved.

[0015] (9) In the catheter according to any one of (1) to (8) above, A grasping member may be provided, and the grasping member may be connected to the proximal end portion. According to this configuration, an operator can easily push the catheter in or easily rotate the catheter by grasping the grasping member.

[0016] In this specification, the term "distal side" refers to the longitudinal direction of the catheter, meaning the direction in which the catheter advances toward the site to be treated (the distal side). The term "proximal side" refers to the longitudinal direction of the catheter, meaning the direction opposite to the above-mentioned distal side (the proximal side). The term "distal end" means the end on the distal side of any member. The term "proximal end" means the end on the proximal side of any member.

[0017] The first to fourth embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited only to the embodiments described in the drawings. The dimensions of each part shown in the drawings are provided to facilitate understanding of the implementation details, and do not necessarily correspond to the actual dimensions.

[0018] In Figures 1, 3, 5, 7-10, the left side of the diagram represents the tip end into which the catheter is pushed, and the right side represents the proximal end (proximal end) manipulated by a physician or other technician.

[0019] [First Embodiment] Figure 1 is a schematic diagram showing a first embodiment. As shown in Figure 1, the catheter 1 comprises, for example, a hollow shaft 11, a tip 21, and a gripping member 31.

[0020] The hollow shaft 11 is a hollow-shaped member having a tip A1 and a base B1. The hollow shaft 11 has, for example, an internal lumen 11h that extends from the tip to the base of the hollow shaft 11.

[0021] The proximal end B1 includes the proximal end of the hollow shaft 11 and extends from the proximal end to the middle of the hollow shaft 11 in the longitudinal direction. The proximal end B1 of the catheter 1 is formed by the proximal shaft 112.

[0022] The proximal end B1 may be set, for example, within 100 mm from the proximal end of the hollow shaft 11 toward the tip. The proximal end B1 may also be within 50 mm from the proximal end of the hollow shaft 11, or it may be 30 mm or less. The entire proximal end B1 is the part that is exposed outside the body during the procedure. Therefore, the length of the proximal end B1 in the longitudinal direction of the hollow shaft 11 can be appropriately determined depending on the procedure in which the catheter 1 is used.

[0023] The tip A1 is the portion that extends from the tip of the proximal end B1 toward the tip of the hollow shaft 11. The tip A1 of the catheter 1 is formed by the tip-side shaft 111.

[0024] The stiffness of the base end B1 of the hollow shaft 11 is less than the stiffness of the tip end A1 of the hollow shaft 11. The stiffness of the tip end A1 and the base end B1 may be constant along the longitudinal direction or may vary. In other words, the distribution of stiffness in the longitudinal direction is not particularly limited as long as the maximum value of the stiffness of the base end B1 is less than the minimum value of the stiffness of the tip end A1. In this embodiment, the stiffness of the tip end A1 and the base end B1 are constant along the longitudinal direction.

[0025] In this specification, "stiffness" is a concept that includes bending stiffness and torsional stiffness. For example, bending stiffness can be measured using a stiffness measuring device 50, as shown in Figure 2. In this measurement method, a test specimen S is placed on support columns 51A and 51B, with a distance of 30 mm between the support points 51a and 51b, and a load is applied to the test specimen S using an indenter 52. The stiffness can be determined by measuring the load and the amount of deflection at that time.

[0026] The degree of rigidity may be determined by the Young's modulus of the material itself, or by the shape of the member. Examples of such shapes include the thickness of shafts 111 and 112.

[0027] The material of the hollow shaft 11 is not particularly limited. Since the catheter 1 is inserted into a body cavity such as a blood vessel, the material of the hollow shaft 11 may have antithrombotic properties, flexibility, and biocompatibility.

[0028] Examples of materials for the hollow shaft 11 include resin materials such as polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluororesin, as well as metal materials such as stainless steel and superelastic alloys (nickel-titanium alloy).

[0029] The tip A1 and base B1 of the hollow shaft 11 may each be formed of a resin material, for example. In this case, the resin material of the tip A1 and the resin material of the base B1 may be the same or different. In this embodiment, the tip A1 and base B1 of the hollow shaft 11 are formed of different resin materials. The cross-sectional shapes of the tip A1 and base B1 are the same. Therefore, the difference in stiffness between the tip A1 and base B1 depends on the stiffness of the resin material itself.

[0030] The tip 21 is a member that extends from the tip of the tip portion A1 of the hollow shaft 11 toward the tip side. The tip 21 can be formed, for example, to taper toward the tip side. The tip 21 of this embodiment has an opening 21a located at the tip and a lumen 21h that penetrates from the tip to the base end.

[0031] The tip 21 may be made of a flexible material to reduce invasiveness to body tissue when inserting the catheter 1 into a body cavity. Examples of materials for the tip 21 include resin materials such as polyurethane, polyurethane elastomer, polyamide, and polyamide elastomer.

[0032] The gripping member 31 is a member used by the operator to grasp the catheter 1. The gripping member 31 can be connected, for example, to the proximal end B1 of the hollow shaft 11. The proximal end of the hollow shaft 11 may be connected to the tip of the gripping member 31 or may be embedded in the gripping member 31. The shape of the gripping member 31 is not particularly limited. The gripping member 31 can be formed, for example, in a shape that is easy for the operator to manipulate. The gripping member 31 of this embodiment has an opening 31a located at the proximal end and a lumen 31h that penetrates from the tip to the proximal end.

[0033] The lumen 21h of the tip 21, the lumen 11h of the hollow shaft 11, and the lumen 31h of the gripping member 31 are in communication, and the lumen 21h, lumen 11h, and lumen 31h form a lumen L. Medical devices such as guide wires are inserted, or liquids such as drug solutions are flowed through the lumen L.

[0034] The method of using catheter 1 will be described. Here, we will illustrate a procedure in which the operator delivers catheter 1 to the site of treatment in the blood vessel, and then the operator injects the drug solution through catheter 1.

[0035] Prior to inserting catheter 1 into the blood vessel, the operator first inserts the guidewire to the site to be treated within the blood vessel. Next, the operator inserts the proximal end of the guidewire, which is exposed outside the body, into the opening 21a of catheter 1 and passes it through lumen L. Then, the operator inserts the tip 21 into the blood vessel and, while grasping the gripping member 31, pushes catheter 1 along the guidewire to the site to be treated.

[0036] When the operator manipulates the catheter 1, even if excessive force is applied to the hollow shaft 11 by, for example, manipulating the gripping member 31, the proximal end B1, which has the least rigidity, will deform first. This allows the operator to detect the abnormality early and, for example, quickly stop the procedure.

[0037] Next, the operator uses catheter 1 to inject the drug solution into the treatment site. Specifically, the operator removes the guidewire from the body while keeping the tip A1 of catheter 1 in place at the treatment site. Then, the operator injects the drug solution into the lumen L through the opening 31a of the gripping member 31. The injected drug solution is ejected from the opening 21a through the lumen L to the treatment site.

[0038] Next, the technician withdraws catheter 1 from the body. Specifically, the technician reinserts the guidewire into the blood vessel through lumen L of catheter 1. Then, the technician withdraws catheter 1 from the body along the guidewire, and then withdraws the guidewire from the body. This completes the procedure using catheter 1.

[0039] As described above, because the catheter 1 has the above configuration, even if excessive force is applied to the hollow shaft 11 by manipulating the gripping member 31 during the procedure, the less rigid proximal end B1 will deform before the tip A1. This allows the operator to detect the abnormality early and, for example, quickly stop the procedure. As a result, it is possible to suppress large deformation of the tip of the hollow shaft 11 inserted into the body.

[0040] In catheter 1, the tip A1 and proximal B1 of the hollow shaft 11 are each formed from a resin material. This allows the hollow shaft 11 to be easily formed.

[0041] In catheter 1, the proximal end B1 of the hollow shaft 11 is located within 100 mm from the proximal end towards the tip of the hollow shaft 11. This allows the section of the hollow shaft 11 with low rigidity to be set to an appropriate length. As a result, the pushability and torque transmission of catheter 1 can be improved.

[0042] In catheter 1, the gripping member 31 is connected to the proximal end B1. This allows the operator to easily push in or rotate catheter 1 by grasping the gripping member 31.

[0043] [Second Embodiment] Figures 3 and 4 are schematic diagrams showing a second embodiment. As shown in Figure 3, the catheter 2 comprises, for example, a hollow shaft 12, a tip 21, and a gripping member 31. The second embodiment differs from the first embodiment in that it includes a hollow shaft 12. The configuration of the tip 21 and the gripping member 31 is the same as in the first embodiment. Therefore, the same parts are denoted by the same reference numerals and their detailed descriptions are omitted. The configuration of the hollow shaft 12, other than the configuration of the hollow shaft 12 shown below, and the manner in which the catheter 2 is used are the same as in the first embodiment.

[0044] The hollow shaft 12 is a hollow-shaped member having a tip portion A2 and a base portion B2. The base portion B2 includes the base end of the hollow shaft 12 and extends from the base end to the middle of the hollow shaft 12 in the longitudinal direction. The base portion B2 is formed by the base-side shaft 122. The tip portion A2 is the portion that extends from the tip of the base portion B2 toward the tip of the hollow shaft 12. The tip portion A2 is formed by the tip-side shaft 121.

[0045] The tip portion A2 and the base portion B2 are each formed of a resin material. The tip portion A2 consists of a single layer containing a first resin material. The base portion B2 has an inner layer 122a formed of a second resin material and an outer layer 122b formed of the first resin material, which is arranged to cover the outer circumference of the inner layer 122a. The first resin material in the tip portion A2 and the first resin material in the base portion B2 are integrally formed.

[0046] The second resin material is a different resin material from the first resin material and has less rigidity than the first resin material. For example, if the thickness of the tip A2 and the base B2, and the outer diameter of the tip A2 and the outer diameter of the base B2 are the same, then the rigidity of the base B2 will be less than that of the tip A2 due to the difference in the rigidity of the materials themselves between the first and second resin materials. Even if the thickness and outer diameter of the tip A2 and the base B2 are different, the rigidity of the base B2 can be made less than that of the tip A2 by appropriately selecting the first and second resin materials. In this embodiment, the outer diameter of the tip A2 and the outer diameter of the base B2 are the same. The thickness of the tip A2 and the thickness of the base B2 are the same, and the thickness of the inner layer 122a and the outer layer 122b are the same.

[0047] Examples of the first and second resin materials include polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluororesin. For example, two resin materials with different rigidities may be selected from these, with the resin material having greater rigidity designated as the first resin material and the other as the second resin material.

[0048] As described above, the catheter 2 has a tip portion A2 made of a resin material containing a first resin material, and a proximal portion B2 made of a resin material containing the first resin material and a second resin material having less rigidity than the first resin material. Therefore, the rigidity of the proximal portion B2 can be effectively reduced compared to the tip portion A2.

[0049] The catheter 2 has a proximal end B2 which consists of an inner layer 122a made of a second resin material and an outer layer 122b made of a first resin material. This allows the surface of the proximal end B2 to be hardened.

[0050] The catheter 2 has a first resin material at the tip A2 and a first resin material at the proximal end B2 that are integrally formed. Therefore, it is possible to effectively prevent the hollow shaft 12 from breaking at the boundary between the tip A2 and the proximal end B2.

[0051] [Third Embodiment] Figures 5 and 6 are schematic diagrams showing a third embodiment. As shown in Figure 5, the catheter 3 comprises, for example, a hollow shaft 13, a tip 21, and a gripping member 31. The third embodiment differs from the second embodiment in that it includes a hollow shaft 13. The configuration of the tip 21 and the gripping member 31 is the same as in the first embodiment. Therefore, the same parts are denoted by the same reference numerals and their detailed descriptions are omitted. The configuration of the hollow shaft 13, other than the configuration of the hollow shaft 13 shown below, and the manner in which the catheter 3 is used are the same as in the second embodiment.

[0052] The hollow shaft 13 is a hollow-shaped member having a tip portion A3 and a base portion B3. The base portion B3 includes the base end of the hollow shaft 13 and extends from the base end to the middle of the hollow shaft 13 in the longitudinal direction. The base portion B3 is formed by the base end shaft 132. The tip portion A3 is the portion that extends from the tip of the base portion B3 toward the tip of the hollow shaft 13. The tip portion A3 is formed by the tip end shaft 131.

[0053] The tip portion A3 and the base portion B3 are each formed of a resin material. The tip portion A3 consists of a single layer containing a first resin material. The base portion B3 has an inner layer 132a formed of the first resin material and an outer layer 132b formed of a second resin material that is arranged to cover the outer circumference of the inner layer 132a. The first resin material in the tip portion A3 and the first resin material in the base portion B3 are integrally formed.

[0054] The second resin material is a different resin material from the first resin material and has less rigidity than the first resin material. For example, if the thickness of the tip A3 and the base B3, and the outer diameter of the tip A3 and the outer diameter of the base B3 are the same, then the rigidity of the base B3 will be less than that of the tip A3 due to the difference in the rigidity of the materials themselves between the first and second resin materials. Even if the thickness and outer diameter of the tip A3 and the base B3 are different, the rigidity of the base B3 can be made less than that of the tip A3 by appropriately selecting the first and second resin materials. In this embodiment, the outer diameter of the tip A3 and the outer diameter of the base B3 are the same. The thickness of the tip A3 and the thickness of the base B3 are the same, and the thickness of the inner layer 132a and the outer layer 132b are the same.

[0055] As described above, the catheter 3 has a tip portion A3 made of a resin material containing a first resin material, and a proximal portion B3 made of a resin material containing the first resin material and a second resin material having less rigidity than the first resin material. Therefore, the rigidity of the proximal portion B3 can be effectively reduced compared to the tip portion A3.

[0056] The catheter 3 has a proximal end B3 which consists of an inner layer 132a made of a first resin material and an outer layer 132b made of a second resin material. This allows the surface of the proximal end B3 to be made flexible.

[0057] The catheter 3 has a first resin material at the tip A3 and a first resin material at the proximal end B3 that are integrally formed. Therefore, it is possible to effectively prevent the hollow shaft 13 from breaking at the boundary between the tip A3 and the proximal end B3.

[0058] [Fourth Embodiment] Figures 7 and 8 are schematic diagrams showing a fourth embodiment. As shown in Figure 7, the catheter 4 comprises, for example, a hollow shaft 14, a tip 21, and a gripping member 31. The fourth embodiment differs from the first embodiment in that it includes a hollow shaft 14. The configuration of the tip 21 and the gripping member 31 is the same as in the first embodiment. Therefore, the same parts are denoted by the same reference numerals and their detailed descriptions are omitted. The configuration of the hollow shaft 14, other than the configuration of the hollow shaft 14 shown below, and the manner in which the catheter 4 is used are the same as in the first embodiment.

[0059] The hollow shaft 14 is a member having a base end B4 including the base end, and a tip A4 extending from the tip of the base end B4 toward the tip. The tip A4 is formed by the tip-side shaft 141. The base end B4 is formed by the base-side shaft 142.

[0060] As shown in Figure 8, the hollow shaft 14 of this embodiment further has a reinforcing body 145 formed of wires w. Examples of the reinforcing body 145 include a coil body formed by winding wires w in a spiral shape, and a braided body formed by weaving wires w into a mesh shape.

[0061] In this embodiment, a braided body (hereinafter also referred to as "braided body 145") is exemplified as the reinforcing body 145. The reinforcing body 145 is embedded in the hollow shaft 14 from the tip A4 to the base B4, along the longitudinal direction of the hollow shaft 14. The pitch p2 of the strands w of the reinforcing body 145 located at the base B4 is greater than the pitch p1 of the strands w of the reinforcing body 145 located at the tip A4. The pitch p of the strands w can be determined, for example, by changing the distance between adjacent strands w. In the catheter 4, the rigidity of the base B4 is made smaller than the rigidity of the tip A4 by changing the pitch p of the strands w, which have a constant wire diameter.

[0062] Examples of materials for the strands w forming the braided body 145 include stainless steel such as SUS304 and SUS316; platinum, tungsten; and resin materials such as reinforced plastics.

[0063] As described above, since the catheter 4 has a braided body 145, the rigidity of the proximal end B4 can be made smaller than that of the tip A4 by changing the pitch p of the strands w. Since the braided body 145 is embedded from the tip A4 to the proximal end B4, it can also prevent the tip shaft 141 and the proximal shaft 142 from separating.

[0064] In the embodiments described above, a catheter 4 in which the tip A4 and proximal B4 of the hollow shaft 14 are formed from different resin materials was described. As shown in Figure 9, the tip A4 and proximal B4 may be formed from the same resin material. In this case, the rigidity of the tip A4 and proximal B4 is determined by changing the pitch p(p1,p2) of the strands w in the tip A4 and proximal B4.

[0065] This disclosure is not limited to the configurations of the embodiments described above. All modifications are intended to be included in the meaning and scope equivalent to the claims, as indicated by the claims. Some of the configurations of the embodiments described above may be deleted or replaced with other configurations. Other configurations may be added to the configurations of the embodiments described above.

[0066] For example, in the second embodiment, a catheter 2 was described in which the proximal end B2 of the hollow shaft 12 consists of an inner layer 122a and an outer layer 122b. In the third embodiment, a catheter 3 was described in which the proximal end B3 of the hollow shaft 13 consists of an inner layer 132a and an outer layer 132b. In the fourth embodiment, a catheter 4 was described in which a hollow shaft 14 having a reinforcing body 145 was described. The proximal end of the hollow shaft may consist of an inner layer and an outer layer, and the reinforcing body may be embedded from the tip to the proximal end. In such a case, the reinforcing body may be embedded in the inner layer or in the outer layer. Figure 10 illustrates a reinforcing body 145 embedded in the proximal end B4 of the hollow shaft 14B so as to straddle the inner layer 143a and the outer layer 143b.

Claims

1. The device comprises a hollow shaft (11, 12, 13, 14, 14A, 14B) having a base end (B1, B2, B3, B4) including the base end, and a tip portion (A1, A2, A3, A4) extending from the tip of the base end (B1, B2, B3, B4) toward the tip, Catheters (1, 2, 3, 4) in which the rigidity of the proximal portion (B1, B2, B3, B4) is less than the rigidity of the tip portion (A1, A2, A3, A4).

2. The hollow shafts (14, 14A, 14B) have reinforcing members (145) formed by strands (w), The reinforcing member (145) is embedded in the hollow shafts (14, 14A, 14B) from the tip (A4) to the base (B4) so ​​as to be along the longitudinal direction of the hollow shafts (14, 14A, 14B), The catheter (4) according to claim 1, wherein the pitch (p2) of the wires (w) of the reinforcing body (145) located at the base end (B4) is greater than the pitch (p1) of the wires (w) of the reinforcing body (145) located at the tip end (A4).

3. The catheter (1, 2, 3, 4) according to claim 1 or claim 2, wherein the tip portions (A1, A2, A3, A4) and the base portions (B1, B2, B3, B4) are each formed of a resin material.

4. The resin material of the aforementioned tip portions (A2, A3) includes the first resin material, The catheter (2, 3) according to claim 3, wherein the resin material of the proximal end portion (B2, B3) comprises the first resin material and a second resin material which is different from the first resin material and has less rigidity than the first resin material.

5. The catheter (2) according to claim 4, wherein the proximal end (B2) comprises an inner layer (122a) formed of the second resin material and an outer layer (122b) formed of the first resin material, which is arranged to cover the outer circumference of the inner layer (122a).

6. The catheter (3) according to claim 4, wherein the proximal end (B3) comprises an inner layer (132a) formed of the first resin material and an outer layer (132b) formed of the second resin material, which is arranged to cover the outer circumference of the inner layer (132a).

7. The catheter (2, 3) according to any one of claims 4 to 6, wherein the first resin material at the tip portion (A2, A3) and the first resin material at the base portion (B2, B3) are integrally formed.

8. The catheter (1, 2, 3, 4) according to any one of claims 1 to 7, wherein the proximal end portion (B1, B2, B3, B4) is a portion within 100 mm from the proximal end toward the tip of the hollow shaft (11, 12, 13, 14, 14A, 14B).

9. Equipped with a gripping member (31), The gripping member (31) is connected to the base end (B1, B2, B3, B4) as described in any one of claims 1 to 8 (1, 2, 3, 4).

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