Catheter

Abstract

To provide a catheter equipped with a shaft having a new lumen structure.SOLUTION: A catheter 1 includes a shaft 11 having a first lumen 12 and a second lumen 16, and a hub 31 provided more on a proximal side than the shaft 11. The first lumen 12 includes a first distal opening 13 and a first proximal opening 14, the first distal opening 13 being located on a distal end of the shaft 11, and the first proximal opening 14 side being connected to the hub 31. The second lumen 16 includes a second distal opening 17 and a second proximal opening 18, the second distal opening 17 side being connected to the first lumen 12, and the second proximal opening 18 being located more on a distal side than the hub 31.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Conventionally, catheters having a shaft with multiple lumens are known. For example, Patent Document 1 discloses a catheter having a first lumen and a second lumen, wherein the first lumen forms a passage from the base end to the tip of the catheter and opens at the tip of the catheter, a predetermined length of the catheter from the tip is reduced in diameter via a tapered step, leaving a tubular portion including the first lumen, and the second lumen forms a passage from the base end to the step and opens at the step. Patent Document 2 discloses a catheter including a catheter body having an outer wall surrounding at least three separate lumens, and the at least three separate lumens including first, second, and third lumens, wherein the distal openings of the second and third lumens are positioned adjacent to each other at approximately the same position along the longitudinal direction of the catheter, and the distal opening of the first lumen is positioned distally or proximally to the distal openings of the second and third lumens along the longitudinal direction of the catheter. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-034652 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-504897 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, catheters equipped with shafts having various lumen structures have been known in the prior art, and an object of the present invention is to provide a catheter equipped with a shaft having a novel lumen structure. [Means for solving the problem]

[0005] The catheter of the present invention that can solve the above problems is as follows. [1] A shaft extending longitudinally from a proximal side to a distal side and having a first lumen and a second lumen; a hub provided proximal to the shaft, The first lumen has a first distal opening and a first proximal opening, the first distal opening is located at a distal end of the shaft, and the first proximal opening side is connected to the hub; The second lumen has a second distal opening and a second proximal opening, the second distal opening side is connected to the first lumen, and the second proximal opening is located distal to the hub. [2] The catheter described in [1], wherein the shaft further has a third lumen, the third lumen having a third distal opening and a third proximal opening, the third distal opening side being connected to the first lumen or the second lumen, and the third proximal opening side being connected to the hub. [3] The catheter described in [1], wherein a guide wire is inserted through the first lumen and the second lumen. [4] The catheter according to [2], wherein the first lumen, the second lumen, and the third lumen are adapted to receive a guidewire. [5] A catheter described in [2] or [4], wherein the connection portion of the third lumen with the first lumen or the second lumen is at a different position in the longitudinal direction from the connection portion of the second lumen with the first lumen. [6] A catheter according to any one of [1] to [5], wherein the connection portion of the second lumen with the first lumen is in a range of 50 mm to 400 mm proximally from the distal end of the shaft. [7] The catheter according to any one of [1] to [6], wherein the length from the second distal opening to the second proximal opening of the second lumen is 10 mm or more and 300 mm or less. [8] The catheter according to any one of [1] to [7], which is a microcatheter. [Effects of the Invention]

[0006] The catheter of the present invention comprises a shaft having a first lumen and a second lumen, and the first and second lumens are configured such that the distal side of the second lumen is connected to the first lumen. Therefore, by inserting a guidewire through each of the first and second lumens and appropriately selecting a guidewire to extend from the distal end of the shaft, it is possible to realize novel methods of using the catheter, such as inserting the catheter deeper into a body lumen. [Brief explanation of the drawings]

[0007] [Figure 1] 1 shows an example of a catheter according to an embodiment of the present invention, and is a side view of the catheter. [Figure 2] FIG. 10 shows another example of a catheter according to an embodiment of the present invention, and is a side view of the catheter. DETAILED DESCRIPTION OF THE INVENTION

[0008] The catheter of the present invention will be specifically described below based on the following embodiments, but the present invention is not limited to the following embodiments and can be modified appropriately within the scope of the above and below-described purposes, and all such modifications are within the technical scope of the present invention. For convenience, hatching and component symbols may be omitted in the drawings. In such cases, reference should be made to the specification or other drawings. The dimensions of various components in the drawings may differ from their actual dimensions, as priority is given to helping understand the features of the present invention.

[0009] A catheter according to an embodiment of the present invention will be described with reference to Figures 1 and 2. Figures 1 and 2 show examples of the configuration of a catheter according to the present invention, with Figure 1 showing a side view of a catheter according to a first embodiment of the present invention and Figure 2 showing a side view of a catheter according to a second embodiment of the present invention.

[0010] The catheter 1 has a shaft 11 extending in the longitudinal direction and a hub 31 provided proximal to the shaft 11. In the catheter 1, the longitudinal direction is determined based on the extension direction of the shaft 11. The catheter 1 has a proximal side and a distal side as one side and the other side of the longitudinal direction. The proximal side refers to the direction toward the user of the catheter 1, i.e., the operator's hand, and the distal side refers to the opposite side of the proximal side, i.e., the direction toward the treatment target. The shaft 11 has a radial direction that is perpendicular to the longitudinal direction. In Figures 1 and 2, the right side of the figure corresponds to the proximal side, and the left side of the figure corresponds to the distal side.

[0011] The length of the shaft 11 in the longitudinal direction is, for example, preferably 1000 mm or more, more preferably 1400 mm or more, and is preferably 4000 mm or less, more preferably 3500 mm or less.

[0012] In the catheter 1 according to the first embodiment shown in Fig. 1, the shaft 11 has a first lumen 12 and a second lumen 16. The first lumen 12 extends in the longitudinal direction and has a first distal opening 13 and a first proximal opening 14. The second lumen 16 extends in the longitudinal direction and has a second distal opening 17 and a second proximal opening 18. In the longitudinal direction of the shaft 11, a portion of the first lumen 12 is arranged radially side by side with the second lumen 16 (i.e., side by side in a vertical cross section in the longitudinal direction).

[0013] The first lumen 12 has a first distal opening 13 located at the distal end of the shaft 11 and is connected to the hub 31 on the side of the first proximal opening 14. The first distal opening 13 faces the outside of the catheter 1. The first lumen 12 may be connected to the hub 31 at any portion on the side of the first proximal opening 14 (for example, a portion within 100 mm distal to the first proximal opening 14), but it is preferable that the first proximal opening 14 be connected to the hub 31. The hub 31 preferably has a first internal passage 33 communicating with the first lumen 12 and has a first port 32 as an inlet to the first internal passage 33, and it is preferable that the first proximal opening 14 be connected to the first internal passage 33 of the hub 31.

[0014] The second lumen 16 is connected to the first lumen 12 on the second distal opening 17 side. That is, the first lumen 12 has a branching portion 19 with the second lumen 16, and the second lumen 16 is formed as a lumen branching from the first lumen 12. It is sufficient that any portion of the second lumen 16 on the second distal opening 17 side (for example, a portion within 100 mm proximally from the second distal opening 17) is connected to the first lumen 12, but it is preferable that the second distal opening 17 is connected to the first lumen 12.

[0015] The second proximal opening 18 of the second lumen 16 is located distal to the hub 31. The second proximal opening 18 faces the exterior of the catheter 1. The second proximal opening 18 is preferably formed at the proximal end of the second lumen 16. The second proximal opening 18 of the second lumen 16 is preferably located in the distal third range of the shaft 11, more preferably in the distal fifth range, and even more preferably in the distal tenth range.

[0016] As described above, the shaft 11 is formed with the first lumen 12 and the second lumen 16, and it is preferable that the first lumen 12 is formed but the second lumen 16 is not formed distal to the bifurcation 19, and that the first lumen 12 and the second lumen 16 are formed proximal to the bifurcation 19 and distal to the second proximal opening 18, and that the first lumen 12 is formed but the second lumen 16 is not formed proximal to the second proximal opening 18. The second lumen 16 can function as a guidewire lumen in a rapid exchange catheter.

[0017] The catheter 1 can be used as follows. First, the catheter 1 is used by inserting a first guidewire through the first lumen 12 and the second lumen 16 between the first distal opening 13 and the second proximal opening 18. For example, the first guidewire is inserted from the first distal opening 13 into the first lumen 12, then passed through the bifurcation 19 and into the second lumen 16, and the first guidewire extends from the second proximal opening 18. The first guidewire extending distally from the distal end of the shaft 11 is inserted into a body lumen such as a blood vessel. However, in a narrow or curved body lumen, the insertability of the first guidewire into the body lumen may be reduced. In such a case, the first guidewire can be pulled back into the second lumen 16 proximal to the bifurcation 19, and instead, a second guidewire can be inserted into the first lumen 12 from the first port 32 of the hub 31 and extended from the first distal opening 13. The second guidewire may be thinner than the first guidewire, have a different rigidity than the first guidewire, have a different lubricity than the first guidewire, or have a different tip shape than the first guidewire. By selecting an appropriate second guidewire depending on the cause of the reduced insertability of the first guidewire into the body lumen, the second guidewire extending distally from the distal end of the shaft 11 can be inserted further into the body lumen. This allows the catheter 1 to be advanced further into the body lumen along the second guidewire. While the second guidewire is inserted through the first lumen 12 and extended from the first distal opening 13, the first guidewire can be kept waiting in the second lumen 16 proximal to the bifurcation 19. The second guidewire is then pulled back to the first lumen 12 proximal to the bifurcation 19, and the first guidewire can be again inserted through the first lumen 12 via the bifurcation 19 and extended from the first distal opening 13. This makes it easy to insert a guidewire into the distal portion of a body lumen. In order to enable such use, it is preferable that the first lumen 12 and the second lumen 16 are ones through which a guidewire can be inserted.

[0018] The length from the second distal opening 17 to the second proximal opening 18 of the second lumen 16 (the longitudinal length of the shaft 11) is preferably 10 mm or more and 300 mm or less. Forming the second lumen 16 in this manner facilitates the operation of inserting the first guide wire from the first distal opening 13, passing through the first lumen 12 and the second lumen 16, and extending from the second proximal opening 18, or of storing the first guide wire in the second lumen 16 proximal to the bifurcation 19. The length from the second distal opening 17 to the second proximal opening 18 of the second lumen 16 is more preferably 30 mm or more, even more preferably 50 mm or more, even more preferably 80 mm or more, more preferably 250 mm or less, even more preferably 200 mm or less, and even more preferably 150 mm or less.

[0019] It is preferable that the catheter 1 is a microcatheter because it is easy to advance the catheter 1 to the peripheral part of a body lumen in cooperation with a guidewire and the catheter 1. If the catheter 1 is a microcatheter, the catheter 1 can be advanced through the body lumen by combining a first guidewire, a second guidewire, and the catheter 1, thereby delivering the catheter 1 and the guidewire to the peripheral part deeper within the body lumen.

[0020] When the catheter 1 is a microcatheter, it is preferable to use the catheter 1 by inserting it into a guiding catheter and extending the portion of the catheter 1 distal to the bifurcation 19 from the distal opening of the guiding catheter. The portion of the catheter 1 distal to the bifurcation 19 can be formed thinner than the portion proximal to the bifurcation 19. Therefore, by extending the portion of the catheter 1 distal to the bifurcation 19 from the distal opening of the guiding catheter, the thin portion of the catheter 1 can be inserted into the peripheral portion of a body lumen. This makes it possible to prevent damage to the inner wall of the body lumen.

[0021] The second lumen 16 may be used to insert a guidewire, and the first lumen 12 proximal to the bifurcation 19 may be used to inject a liquid such as a contrast agent or a drug. For example, with a typical microcatheter, it is difficult to inject a contrast agent or a drug with a guidewire inserted in the lumen, and the guidewire must be removed before the contrast agent or drug can be injected. However, with the catheter 1, the guidewire can be pulled back into the second lumen 16 proximal to the bifurcation 19 and then the liquid such as a contrast agent or a drug can be injected through the first port 32 of the hub 31. This allows the liquid to pass through the first lumen 12 and reach the first distal opening 13, and then be expelled from the distal end of the shaft 11.

[0022] The junction of the second lumen 16 with the first lumen 12, i.e., the branching portion 19 where the second lumen 16 branches off from the first lumen 12, is preferably in a range of 50 mm to 400 mm proximal from the distal end of the shaft 11. This range is more preferably 100 mm or more proximal from the distal end of the shaft 11, even more preferably 150 mm or more, even more preferably 200 mm or more, and more preferably 350 mm or less. If the junction of the second lumen 16 with the first lumen 12 is located in this position, the guidewire is prevented from unintentionally extending from the first distal opening 13 during manipulation of the guidewire, and the guidewire can be easily pulled back to the junction of the second lumen 16 with the first lumen 12, i.e., the branching portion 19. When the catheter 1 is a microcatheter, a sufficient length can be ensured for the catheter 1 to extend from the distal opening of the guiding catheter.

[0023] As in the catheter 1 according to the second embodiment shown in Fig. 2, the shaft 11 may further have a third lumen 21. For descriptions of the first lumen 12 and the second lumen 16 in the catheter 1 according to the second embodiment, refer to the descriptions of those in the catheter 1 according to the first embodiment above. The third lumen 21 extends in the longitudinal direction and has a third distal opening 22 and a third proximal opening 23. It is preferable that a portion of the first lumen 12 is arranged radially alongside the third lumen 21 in the longitudinal direction of the shaft 11.

[0024] The third lumen 21 can be configured so that the third proximal opening 23 side is connected to the hub 31. In this case, the hub 31 preferably includes a second internal passage 35 that communicates with the third lumen 21 and has a second port 34 as an inlet to the second internal passage 35. The second internal passage 35 may be connected to the first internal passage 33 inside the hub 31, or may be formed independently without being connected inside the hub 31; however, the latter configuration is preferred. Any portion of the third lumen 21 on the third proximal opening 23 side (e.g., a portion within 100 mm distal to the third proximal opening 23) may be connected to the hub 31; however, it is preferred that the third proximal opening 23 be connected to the hub 31, and that the third proximal opening 23 be connected to the second internal passage 35 of the hub 31.

[0025] The third lumen 21 can be configured so that the third distal opening 22 side is connected to the first lumen 12 or the second lumen 16. In this case, the first lumen 12 or the second lumen 16 has a branching portion 24 with the third lumen 21, and the third lumen 21 is formed as a lumen branching from the first lumen 12 or the second lumen 16. In FIG. 2 , the third distal opening 22 of the third lumen 21 is connected to the first lumen 12, and the third lumen 21 branches off from the first lumen 12 at the branching portion 24. Any portion of the third lumen 21 on the third distal opening 22 side (for example, a portion within 100 mm proximally of the third distal opening 22) may be connected to the first lumen 12 or the second lumen 16, but it is preferable that the third distal opening 22 be connected to the first lumen 12 or the second lumen 16. Therefore, it is preferable that the shaft 11 has the first lumen 12 formed distal to the branching portion 19 and distal to the branching portion 24, but does not have the second lumen 16 and the third lumen 21 formed therein, and that the first lumen 12 and the third lumen 21 are formed proximal to the branching portion 19, proximal to the branching portion 24, and proximal to the second proximal opening 18.

[0026] The third lumen 21 can be used, for example, to pass a guidewire through it. As described above, the first lumen 12 and the second lumen 16 can be used to pass a guidewire through them, but the third lumen 21 can also be used to pass a guidewire through it. If the insertability of the first guidewire into the body lumen is reduced and the insertability into the body lumen is not improved even by using the second guidewire, the first guidewire and the second guidewire are pulled back proximal to the bifurcation 19 and the bifurcation 24, and instead a third guidewire is inserted into the third lumen 21 from the second port 34 of the hub 31. The third guidewire inserted into the third lumen 21 is then passed through the bifurcation 24 and into the first lumen 12, thereby allowing the third guidewire to extend from the first distal opening 13. By selecting an appropriate guidewire as the third guidewire, the third guidewire extending distally from the distal end of the shaft 11 can be inserted further into the body lumen. This allows the catheter 1 to be advanced further into the body lumen along the third guidewire. As the third guidewire, it is preferable to use a guidewire that has a shape and / or physical properties different from those of the first and second guidewires.

[0027] The third lumen 21 may be used to inject a liquid such as a contrast agent or a drug. In this case, it is preferable that the first lumen 12 and the second lumen 16 are used to allow a guidewire to pass through them. For example, by pulling the first guidewire back into the second lumen 16 proximal to the branching portion 19 and pulling the second guidewire back into the first lumen 12 proximal to the branching portion 19, and injecting a liquid such as a contrast agent or a drug through the second port 34 of the hub 31 in this state, the liquid will pass through the third lumen 21, the branching portion 24, and the first lumen 12 to reach the first distal opening 13 and can be expelled from the distal end of the shaft 11.

[0028] Regarding the longitudinal position of the branching portion 24, in FIG. 2 the branching portion 24 is located proximal to the branching portion 19, but the branching portion 24 may be located at the same longitudinal position as the branching portion 19 or may be located distal to the branching portion 19. When the third distal opening 22 of the third lumen 21 is connected to the first lumen 12, the branching portion 24 may be located distal to the second proximal opening 18, may be located at the same longitudinal position as the second proximal opening 18, or may be located proximal to the second proximal opening 18. Note that when a third guidewire is inserted through the third lumen 21, it is preferable that the branching portion 24 be located distal to the second proximal opening 18, since this facilitates the operation of pulling the third guidewire back into the third lumen 21, which is proximal to the branching portion 24.

[0029] The connection portion of the third lumen 21 with the first lumen 12 or the second lumen 16, i.e., the branch portion 24 where the third lumen 21 branches off from the second lumen 16 or the first lumen 12, is preferably located at a different longitudinal position from the connection portion of the second lumen 16 with the first lumen 12, i.e., the branch portion 19 where the second lumen 16 branches off from the first lumen 12. This prevents the radial size of the shaft 11 from becoming too large at the lumen branch portion.

[0030] The connection portion of the third lumen 21 with the first lumen 12 or the second lumen 16, i.e., the branch portion 24 where the third lumen 21 branches off from the first lumen 12 or the second lumen 16, is preferably in a range of 50 mm to 400 mm proximal from the distal end of the shaft 11. This range is more preferably 100 mm or more proximal from the distal end of the shaft 11, even more preferably 150 mm or more, even more preferably 200 mm or more, and more preferably 350 mm or less. This prevents the guidewire from unintentionally extending from the first distal opening 13 during manipulation of the guidewire, and also makes it easier to pull the guidewire back proximal to the branch portion 24.

[0031] The shaft 11 of the catheter 1 according to the first embodiment, i.e., the shaft 11 having the first lumen 12 and the second lumen 16, can be configured, for example, as follows: That is, the shaft 11 has a first tube 15 and a second tube 20, and the inner lumen of the first tube 15 can be the first lumen 12, and the inner lumen of the second tube 20 can be the second lumen 16. A first distal opening 13 is formed at the distal end of the first tube 15, a first proximal opening 14 is formed at the proximal end of the first tube 15, a second distal opening 17 is formed at the distal end of the second tube 20, and a second proximal opening 18 is formed at the proximal end of the second tube 20. The longitudinal length of the second tube 20 is shorter than the longitudinal length of the first tube 15, the second distal opening 17 is located proximal to the first distal opening 13, and the second proximal opening 18 is located distal to the first proximal opening 14. A side opening is provided on the side surface of the first tube 15, and the second distal opening 17 of the second tube 20 is connected to the side opening of the first tube 15. By connecting the first tube 15 and the second tube 20 in this manner, it is possible to form a shaft 11 having a lumen in which the second lumen 16 branches off midway through the first lumen 12.

[0032] The first tube 15 and the second tube 20 may be integrated by welding or bonding to each other, or the first tube 15 and the second tube 20 may be placed in the inner cavity of a protective tube 26, and the first tube 15 and the second tube 20 may be integrated by the protective tube 26.

[0033] The shaft 11 of the catheter 1 according to the second embodiment, i.e., the shaft 11 having a first lumen 12, a second lumen 16, and a third lumen 21, can be configured, for example, as follows: That is, the shaft 11 has a first tube 15, a second tube 20, and a third tube 25, and the inner lumen of the first tube 15 can be the first lumen 12, the inner lumen of the second tube 20 can be the second lumen 16, and the inner lumen of the third tube 25 can be the third lumen 21. A first distal opening 13 is formed at the distal end of the first tube 15, a first proximal opening 14 is formed at the proximal end of the first tube 15, a second distal opening 17 is formed at the distal end of the second tube 20, a second proximal opening 18 is formed at the proximal end of the second tube 20, a third distal opening 22 is formed at the distal end of the third tube 25, and a third proximal opening 23 is formed at the proximal end of the third tube 25. The longitudinal lengths of the second tube 20 and the third tube 25 are shorter than the longitudinal length of the first tube 15, and the second distal opening 17 and the third distal opening 22 are located proximally of the first distal opening 13. The second proximal opening 18 is located distally of the first proximal opening 14 and the third proximal opening 23. A first side opening is provided on the side surface of the first tube 15, and the second distal opening 17 of the second tube 20 is connected to the first side opening of the first tube 15. A second side opening is provided on the side surface of the first tube 15 or the second tube 20, and the third distal opening 22 of the third tube 25 is connected to the second side opening of the first tube 15 or the second tube 20. By connecting the first tube 15, the second tube 20, and the third tube 25 in this manner, a shaft 11 can be formed having a lumen in which the second lumen 16 branches off from the middle of the first lumen 12, and the third lumen 21 branches off from the middle of the first lumen 12 or the second lumen 16.

[0034] The first tube 15, the second tube 20, and the third tube 25 may be integrated by welding or bonding to each other, or the first tube 15, the second tube 20, and the third tube 25 may be placed in the inner cavity of a protective tube 26, and the first tube 15, the second tube 20, and the third tube 25 may be integrated by the protective tube 26.

[0035] The outer diameter of shaft 11 is, for example, preferably 0.6 mm or more, more preferably 0.8 mm or more, even more preferably 1.0 mm or more, even more preferably 1.2 mm or more, and is preferably 8.0 mm or less, more preferably 7.0 mm or less, and even more preferably 6.0 mm or less. The outer diameter of shaft 11 may be smaller, for example, 4.0 mm or less, 3.6 mm or less, or 3.2 mm or less.

[0036] The inner diameters of the first lumen 12, the second lumen 16, and the third lumen 21 are preferably, for example, 0.2 mm or more, more preferably 0.3 mm or more, even more preferably 0.4 mm or more, and are preferably 3.5 mm or less, more preferably 3.0 mm or less, and even more preferably 2.5 mm or less. The inner diameters of the first lumen 12, the second lumen 16, and the third lumen 21 may be smaller, for example, 2.2 mm or less, 2.0 mm or less, or 1.9 mm or less.

[0037] In a vertical cross section of the shaft 11 in the longitudinal direction, the shapes of the outer edge of the shaft 11, the first lumen 12, the second lumen 16, and the third lumen 21 are not particularly limited, and examples thereof include circular, elliptical, oblong, oval, polygonal, and irregular shapes. When the shape of the outer edge of the shaft 11 or the shapes of the first lumen 12, the second lumen 16, and the third lumen 21 are other than circular, the outer diameter of the shaft 11 and the inner diameters of the first lumen 12, the second lumen 16, and the third lumen 21 described above refer to the average values ​​of the major and minor axes. Regarding the major and minor axes, taking the outer edge of the shaft 11 as an example, the major axis of the outer edge of the shaft 11 refers to the length in the major axis direction of the outer edge of the shaft 11 (the maximum diameter of the outer edge), and the minor axis of the outer edge of the shaft 11 refers to the longest length in the minor axis direction, which is perpendicular to the major axis direction of the shaft 11. The shapes of the first lumen 12, the second lumen 16, and the third lumen 21 are preferably circular, oval, or elliptical.

[0038] The shaft 11, the first tube 15, the second tube 20, the third tube 25, and the protective tube 26 can be made of resin. Examples of resin include synthetic resins such as polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon, polyester resins such as polyethylene terephthalate, aromatic polyether ketone resins such as PEEK, polyether polyamide resins, polyurethane resins, polyimide resins, polyamide imide resins, fluorine-based resins such as PTFE, PFA, and ETFE, polyvinyl chloride resins, and silicone resins.

[0039] The shaft 11, the first tube 15, the second tube 20, the third tube 25, and the protective tube 26 may be made of a single layer or multiple layers. The shaft 11, the first tube 15, the second tube 20, the third tube 25, and the protective tube 26 may have a portion in the longitudinal direction made of a single layer and another portion made of multiple layers.

[0040] The shaft 11, the first tube 15, the second tube 20, the third tube 25, and the protective tube 26 may have a reinforcing layer. The reinforcing layer can increase the rigidity of the shaft 11. The reinforcing layer is preferably disposed between an inner layer and an outer layer made of resin.

[0041] The reinforcing layer can be made of metal wires, fibers, etc. Examples of materials for making metal wires include stainless steel, titanium, nickel-titanium alloys, cobalt-chromium alloys, and tungsten alloys. Of these, stainless steel is preferred. The metal wires may be solid or twisted. Examples of fibers include polyarylate fibers, aramid fibers, ultra-high molecular weight polyethylene fibers, PBO fibers, and carbon fibers. The fibers may be monofilaments or multifilaments.

[0042] The shape of the reinforcing layer is not particularly limited, but is preferably spiral, mesh, or braided. Of these, the reinforcing layer is more preferably braided because the reinforcing layer can effectively increase the rigidity of shaft 11.

[0043] The shaft 11 may contain a radiopaque material to facilitate confirmation of its position under X-ray fluoroscopy. Examples of radiopaque materials include lead, barium, iodine, tungsten, gold, platinum, iridium, platinum-iridium alloy, stainless steel, titanium, cobalt-chromium alloy, palladium, and tantalum. For example, a radiopaque marker 27 is preferably provided at the distal end of the shaft 11, allowing confirmation of the position of the tip of the shaft 11 in the body lumen under X-ray fluoroscopy. It is also preferable to provide a radiopaque marker near the bifurcation of the lumen. In FIGS. 1 and 2, a radiopaque marker 28 is provided near the bifurcation 19. This makes it easier to retract the guidewire proximal to the bifurcation 19 under X-ray fluoroscopy. In FIGS. 1 and 2, a radiopaque marker 29 is provided near the second proximal opening 18. This makes it possible to prevent the guide wire from accidentally coming out of the second proximal opening 18 when the guide wire is pulled back into the second lumen 16 proximal to the branching portion 19 under X-ray fluoroscopy.

[0044] The outer surface of the shaft 11 may be coated with a hydrophilic polymer. This allows the shaft 11 to be easily inserted into the forceps channel through the forceps port of the endoscope. Examples of hydrophilic polymers include polyethylene glycol, poly (2-hydroxyethyl methacrylate), polyacrylamide, polyvinylpyrrolidone, and maleic anhydride copolymers such as methyl vinyl ether-maleic anhydride copolymers. [Explanation of symbols]

[0045] 1: Catheter 11: Shaft 12: 1st lumen 13: First distal opening 14: First proximal opening 15: First tube 16: Second lumen 17: Second distal opening 18: Second proximal opening 19: Branch 20: Third tube 21: 3rd lumen 22: Third distal opening 23: Third proximal opening 24: Branch 25: 3rd tube 26: Protective tube 27, 28, 29: X-selection opaque marker 31: Hub 32: First port 33: 1st internal passage 34: Second port 35:Second internal passage

Claims

1. a shaft extending longitudinally from a proximal side to a distal side and having a first lumen and a second lumen; a hub provided proximal to the shaft, The first lumen has a first distal opening and a first proximal opening, the first distal opening is located at a distal end of the shaft, and the first proximal opening side is connected to the hub; The second lumen has a second distal opening and a second proximal opening, the second distal opening side is connected to the first lumen, and the second proximal opening is located distal to the hub.

2. the shaft further has a third lumen; The catheter according to claim 1, wherein the third lumen has a third distal opening and a third proximal opening, the third distal opening side being connected to the first lumen or the second lumen, and the third proximal opening side being connected to the hub.

3. 2. The catheter according to claim 1, wherein a guide wire is inserted through the first lumen and the second lumen.

4. 3. The catheter according to claim 2, wherein a guide wire is inserted through the first lumen, the second lumen, and the third lumen.

5. The catheter according to claim 2 , wherein a connection portion of the third lumen with the first lumen or the second lumen is located at a different position in the longitudinal direction from a connection portion of the second lumen with the first lumen.

6. The catheter according to claim 1 , wherein the connection portion of the second lumen with the first lumen is located in a range of 50 mm to 400 mm proximally from the distal end of the shaft.

7. The catheter according to claim 1, wherein the length of the second lumen from the second distal opening to the second proximal opening is 10 mm or more and 300 mm or less.

8. The catheter according to any one of claims 1 to 7, which is a microcatheter.

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