Catheter

Abstract

The present invention provides a catheter which is easy to insert into a meandering part in a body. The catheter comprises a first tubular member which extends in the lengthwise direction, a second tubular member which extends in the lengthwise direction and which is adjacent to the first tubular member in the radial direction, and an outer member which extends in the lengthwise direction and which has a portion that encloses at least part of the first tubular member and at least part of the second tubular member. The distal end of the first tubular member is positioned further to the proximal side than the distal end of the second tubular member. The proximal end of the first tubular member is positioned further to the proximal side than the proximal end of the second tubular member. The outer member has a first region that, on the distal side from the proximal end of the second tubular member, extends in the lengthwise direction, and a second region that extends in the lengthwise direction and that is positioned further to the distal side than the first region. The value of the ratio of a long axis to a short axis in a radial cross-section of the first region is 1.0-1.1. The value of the ratio of a long axis to a short axis in a radial cross-section of the second region is 1.2-2.0.

Description

catheter

[0001] The present invention relates to a catheter.

[0002] Catheters that can be inserted into blood vessels or the like to examine and treat lesions in the human body are used. For example, Patent Document 1 discloses an example of such a catheter, comprising: a first tubular member extending in the longitudinal direction, having a distal end and a proximal end, and into which a wire is inserted; and a second tubular member having a distal end and a proximal end and radially adjacent to the first tubular member, wherein the distal end of the first tubular member is located proximal to the distal end of the second tubular member, and the proximal end of the first tubular member is located proximal to the proximal end of the second tubular member, the first tubular member having a reinforcing portion including an inner layer containing at least one selected from the group consisting of polytetrafluoroethylene and a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer and a reinforcing member, and the first tubular member having, distal to the distal end of the reinforcing portion, an extension portion made of a resin that does not contain the polytetrafluoroethylene, the tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, or the reinforcing member.

[0003] International Publication No. 2020 / 255737

[0004] Conventional catheters such as those described in Patent Document 1 can be difficult to insert into blood vessels that have continuous three-dimensional meandering, such as coronary arteries. The present invention has been made in light of the above circumstances, and its object is to provide a catheter that can be easily inserted into meandering sections inside the body.

[0005] The catheter according to the embodiment of the present invention that can solve the above problems is as follows: [1] A catheter having a first tubular member extending in a longitudinal direction, a second tubular member extending in the longitudinal direction and adjacent to the first tubular member in a radial direction, and an outer member extending in the longitudinal direction and having a portion that contains at least a part of the first tubular member and at least a part of the second tubular member, wherein a distal end of the first tubular member is located proximal to a distal end of the second tubular member, and a proximal end of the first tubular member is located proximal to a proximal end of the second tubular member, The outer member has a first region extending in the longitudinal direction distal to the proximal end of the second tubular member, and a second region extending in the longitudinal direction and located distal to the first region, wherein the ratio of the major axis to the minor axis in the radial cross section of the first region is 1.0 to 1.1, and the ratio of the major axis to the minor axis in the radial cross section of the second region is 1.2 to 2.0.

[0006] The inventors' studies have revealed that a catheter with a circular radial cross-section, such as that described in Patent Document 1, has difficulty bending along the shape of a tortuous section with continuous three-dimensional meandering, such as a coronary artery. Furthermore, the inventors' studies have also revealed that, while an elliptical radial cross-section makes it easier for the catheter to bend along the shape of a tortuous section, it becomes more difficult to push the catheter into the body. Furthermore, the inventors' studies have revealed that by positioning the second region, whose major axis / minor axis ratio in the radial cross-section is 1.2 to 2.0, more distally than the first region, whose major axis / minor axis ratio is 1.0 to 1.1, the catheter becomes easier to bend along the shape of a tortuous section and easier to push into the body. This makes it easier to insert the catheter into a tortuous section in the body.

[0007] Furthermore, the catheter according to the embodiment is preferably any one of the following [2] to

[22] . [2] The catheter according to [1], wherein the shape of the outer edge of the first region in the radial cross section is a circle or an ellipse, and the shape of the outer edge of the second region in the radial cross section is an ellipse or a partial shape of an ellipse. [3] The catheter according to [1] or [2], wherein the outer member has a third region between the first region and the second region in the longitudinal direction, and the ratio of the major axis to the minor axis of the third region in the radial cross section is greater than 1.1 and less than 1.2. [4] The catheter according to any one of [1] to [3], wherein the length of the second region in the longitudinal direction is shorter than the length of the first region in the longitudinal direction. [5] The catheter according to any one of [1] to [4], wherein the area of ​​the region enclosed by the outer edge of the first region in the radial cross section is greater than or equal to the area of ​​the region enclosed by the outer edge of the second region in the radial cross section. [6] The catheter according to any one of [1] to [5], wherein the major axis of the second region is greater than or equal to the major axis of the first region. [7] The catheter according to any one of [1] to [5], wherein the major axis of the second region is smaller than the major axis of the first region. [8] The catheter according to any one of [1] to [7], wherein the shortest distance in the radial direction from the outer edge of the second region of the outer member to the outer edge of the first tubular member is greater than or equal to the shortest distance from the outer edge of the first region of the outer member to the outer edge of the first tubular member. [9] The catheter according to any one of [1] to [7], wherein the shortest distance in the radial direction from the outer edge of the second region of the outer member to the outer edge of the first tubular member is shorter than the shortest distance from the outer edge of the first region of the outer member to the outer edge of the first tubular member.

[10] A catheter described in any of [1] to [9], wherein in the radial direction, the shortest distance from the outer edge of the second region of the outer member to the outer edge of the second tubular member is longer than or the same as the shortest distance from the outer edge of the first region of the outer member to the outer edge of the second tubular member.

[11] The catheter according to any one of [1] to [9], wherein the shortest distance in the radial direction from the outer edge of the second region of the outer member to the outer edge of the second tubular member is shorter than the shortest distance from the outer edge of the first region of the outer member to the outer edge of the second tubular member.

[12] The catheter according to any one of [1] to

[11] , wherein the outer member is tubular and has an inner lumen extending in the longitudinal direction, and at least a portion of the first tubular member and at least a portion of the second tubular member are disposed in the lumen.

[13] The catheter according to any one of [1] to

[11] , wherein the outer member has a columnar body extending in the longitudinal direction and containing resin, and at least a portion of the first tubular member and at least a portion of the second tubular member are disposed within the columnar body.

[14] The catheter according to any one of [1] to

[13] , further comprising an outer tubular member extending in the longitudinal direction, and the outer tubular member has an inner lumen extending in the longitudinal direction, and a portion of the first tubular member is disposed in the lumen.

[15] The catheter according to

[14] , wherein the outer tubular member is located proximal to the proximal end of the second tubular member.

[16] The catheter according to

[14] or

[15] , wherein the outer tubular member has a fourth region extending in the longitudinal direction proximal to the proximal end of the second tubular member, and the ratio of the major axis to the minor axis in the radial cross section of the fourth region is 1.0 to 1.1.

[17] The catheter according to

[16] , wherein the major axis of the second region is smaller than the major axis of the fourth region.

[18] The catheter according to

[16] or

[17] , wherein the length of the fourth region in the longitudinal direction is longer than the sum of the length of the first region in the longitudinal direction and the length of the second region in the longitudinal direction.

[19] The catheter according to any of

[16] to

[18] , wherein the catheter includes a linear member extending in the longitudinal direction, disposed within at least the first region and the fourth region, and having a distal end located within the first region.

[20] A catheter described in any of [1] to

[19] , wherein the outer member has a fifth region extending in the longitudinal direction and located distal to the second region, and the ratio of the major axis to the minor axis in the radial cross section of the fifth region is 1.0 to 1.1.

[21] The catheter according to any one of [1] to

[20] , wherein the first tubular member and the second tubular member are fixed to each other in the radial direction.

[22] The catheter according to any one of [1] to

[21] , wherein a handle portion is disposed at the proximal end of the first tubular member.

[0008] According to the present invention, with the above-mentioned configuration, it is possible to provide a catheter that can be easily inserted into a tortuous part inside the body.

[0009] FIG. 1 is a side view of a catheter according to a first embodiment. FIG. 2 is a longitudinal cross-sectional view of region R1 in FIG. 1. FIG. 3 is a longitudinal cross-sectional view of region R2 in FIG. 1. FIG. 4 is an A-A cross-sectional view of the catheter in FIG. 1. FIG. 5 is a B-B cross-sectional view of the catheter in FIG. 1. FIG. 6 is a C-C cross-sectional view of the catheter in FIG. 1. FIG. 7 is a D-D cross-sectional view of the catheter in FIG. 1. FIG. 8 is an E-E cross-sectional view of the catheter in FIG. 1. FIG. 9 is a longitudinal cross-sectional view of region R2 in a modified example of the catheter in FIG. 1. FIG. 10 is a side view of a catheter according to a second embodiment. FIG. 11 is a longitudinal cross-sectional view of region R1 in FIG. 10. FIG. 12 is a longitudinal cross-sectional view of region R2 in FIG. 10. FIG. 13 is an A-A cross-sectional view of the catheter in FIG. 10. FIG. 14 is a B-B cross-sectional view of the catheter in FIG. 10. FIG. 15 is a C-C cross-sectional view of the catheter in FIG. 10. FIG. 16 is a cross-sectional view of a variation of the catheter of FIG.

[0010] The present invention will be described in more detail below based on the following embodiments. However, the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the above and below-described purposes, and all such modifications are included within the technical scope of the present invention. Note that, for convenience, component reference numerals may be omitted in the drawings. In such cases, reference should be made to the specification or other drawings. Furthermore, 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.

[0011] A catheter according to an embodiment of the present invention has a first tubular member extending in the longitudinal direction, a second tubular member extending in the longitudinal direction and radially adjacent to the first tubular member, and an outer member extending in the longitudinal direction and having a portion enclosing at least a portion of the first tubular member and at least a portion of the second tubular member, wherein the distal end of the first tubular member is located proximal to the distal end of the second tubular member, and the proximal end of the first tubular member is located proximal to the proximal end of the second tubular member, and the outer member has, distal to the proximal end of the second tubular member, a first region extending in the longitudinal direction and a second region extending in the longitudinal direction and located distal to the first region, wherein the ratio of the major axis to the minor axis in a radial cross section of the first region is 1.0 to 1.1, and the ratio of the major axis to the minor axis in a radial cross section of the second region is 1.2 to 2.0.

[0012] The inventors' studies have revealed that a catheter with a circular radial cross-section has difficulty bending along the shape of a tortuous section with continuous three-dimensional meandering, such as a coronary artery. Furthermore, the inventors' studies have also revealed that, while an elliptical radial cross-section makes it easier for the catheter to bend along the shape of a tortuous section, it becomes more difficult to push the catheter into the body. Furthermore, the inventors' studies have revealed that by positioning the second region, in which the major axis / minor axis ratio in the radial cross-section is 1.2 to 2.0, more distally than the first region, in which the major axis / minor axis ratio is 1.0 to 1.1, the catheter becomes easier to bend along the shape of a tortuous section and easier to push into the body. This makes it easier to insert the catheter into a tortuous section in the body.

[0013] A catheter according to a first embodiment will be described below with reference to Figures 1 to 9 and 16. Figure 1 is a side view of the catheter according to the first embodiment. Figure 2 is a longitudinal cross-sectional view of region R1 in Figure 1. Figure 3 is a longitudinal cross-sectional view of region R2 in Figure 1. Figure 4 is an A-A cross-sectional view of the catheter in Figure 1. Figure 5 is a B-B cross-sectional view of the catheter in Figure 1. Figure 6 is a CC cross-sectional view of the catheter in Figure 1. Figure 7 is a D-D cross-sectional view of the catheter in Figure 1. Figure 8 is an E-E cross-sectional view of the catheter in Figure 1. Figure 9 is a longitudinal cross-sectional view of region R2 in a modified version of the catheter in Figure 1. Figure 16 is a cross-sectional view of a modified version of the catheter in Figure 5.

[0014] As shown in FIGS. 1 , 2 , and 3 , the catheter according to the first embodiment is a catheter 91 having a first tubular member 1 extending in the longitudinal direction X and a second tubular member 2 extending in the longitudinal direction X and adjacent to the first tubular member 1 in the radial direction Y. Specifically, the outer surfaces of the first tubular member 1 and the second tubular member 2 are preferably adjacent to each other in the radial direction Y. The first tubular member 1 preferably has a lumen 1L extending in the longitudinal direction X. The second tubular member 2 preferably has a lumen 2L extending in the longitudinal direction X. By inserting, for example, a guidewire into each of the lumen 1L and the lumen 2L, the catheter 91 can be guided in multiple directions, thereby facilitating insertion of the catheter 91 into various branching portions of coronary arteries, for example. Furthermore, by inserting a searching wire into the lumen 1L or the lumen 2L, it is possible to easily search for the entrance of a stenotic lesion, for example. Of these, it is preferable to insert the searching wire into the lumen 1L. The tip of the probe wire may be bent.

[0015] The first tubular member 1 and the second tubular member 2 each preferably have one or more layers extending in the longitudinal direction X, and more preferably have multiple layers. The multiple layers preferably include an inner layer and an outer layer enclosing at least a portion of the inner layer. The multiple layers may further include an intermediate layer positioned between the inner layer and the outer layer. The number of intermediate layers is not limited to one, but may be two or more. It is preferable that each of the multiple layers contains a different material from the adjacent layers. The inner layer of the first tubular member 1 and the inner layer of the second tubular member 2 each preferably contains at least one resin selected from the group consisting of polyolefin resins and fluorine-based resins. This improves the slidability of the wire inserted into the lumen 1L and the lumen 2L. The polyolefin resin is preferably polyethylene, polypropylene, an ethylene-propylene copolymer, or a mixture thereof. The polyethylene is preferably high-density polyethylene with a specific gravity of 0.942 or higher. The fluorine-based resin is preferably polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, polyvinylidene fluoride, polychlorotrifluoroethylene, ethylene-chlorotrifluoroethylene copolymer, or a mixture thereof. The inner layer of the first cylindrical member 1 and the inner layer of the second cylindrical member 2 may each contain at least one selected from the group consisting of polyamide-based resin, polyester-based resin, polyurethane-based resin, polyolefin-based resin, fluorine-based resin, vinyl chloride-based resin, silicone-based resin, and natural rubber. The inner layer of the first cylindrical member 1 and the inner layer of the second cylindrical member 2 may contain different resins, but preferably contain the same resin, and more preferably are made of the same resin.

[0016] The outer layer of the first tubular member 1 and the outer layer of the second tubular member 2 each preferably contain a flexible resin. When the outer layers contain a flexible resin, the catheter 91 becomes more easily bendable. The flexible resin preferably contains at least one selected from the group consisting of polyethylene, polyurethane, polyurethane-based thermoplastic elastomer, styrene-based thermoplastic elastomer, polyamide elastomer, and polyamide, and more preferably contains at least one selected from the group consisting of polyurethane and polyamide elastomer. The polyethylene is preferably low-density polyethylene with a specific gravity of 0.91 to 0.92.

[0017] The Shore D hardness of the material of the outer layer is preferably equal to or smaller than the Shore D hardness of the material of the inner layer, and more preferably smaller, which makes the catheter 91 more flexible. The Shore D hardness may be measured, for example, using a durometer type D in accordance with ISO 7619.

[0018] The intermediate layer preferably comprises a different material than the inner or outer layer, but may comprise the same material as the inner or outer layer.

[0019] The inner layer, intermediate layer, and outer layer are preferably fixed to the adjacent layers, which makes each layer less likely to twist or distort. Fixing methods include welding and adhesion. Although not shown, a reinforcing member may be disposed as the intermediate layer.

[0020] The first tubular member 1 preferably includes a reinforcing member, which can easily prevent the wire from breaking through the first tubular member 1. On the other hand, the second tubular member 2 preferably does not include a reinforcing member, which can easily improve the flexibility of the second tubular member 2.

[0021] The reinforcing member is preferably a braided body made of braided wires, a coiled body made of spirally wound wires, or a combination thereof. This can more easily prevent the wire from breaking through the first tubular member 1. Of these, a braided body is more preferable as the reinforcing member because it is more likely to improve rigidity. Examples of wires contained in the reinforcing member include metal wires and fibers. The metal wire preferably includes stainless steel, titanium, a nickel-titanium alloy, a cobalt-chromium alloy, a tungsten alloy, or an alloy thereof. Of these, stainless steel is more preferable. The metal wire may be a solid wire or a twisted wire. The fiber is preferably polyarylate fiber, aramid fiber, ultra-high molecular weight polyethylene fiber, PBO fiber, carbon fiber, or a blend thereof. The fiber may be monofilament or multifilament. The reinforcing member may include a radiopaque material to make it easier to confirm the position of the first tubular member 1 under X-ray fluoroscopy, etc. The radiopaque material is preferably at least one selected from the group consisting of lead, barium, iodine, tungsten, gold, platinum, iridium, platinum-iridium alloy, stainless steel, titanium, cobalt-chromium alloy, palladium, bismuth, and tantalum.

[0022] Although not shown, the distal end of the reinforcing member is preferably located proximal to the proximal end of the first opening 1E and distal to the proximal end 2A of the second tubular member 2. On the other hand, the proximal end of the reinforcing member is preferably located proximal to the proximal end 2A of the second tubular member 2, and more preferably located within the handle portion 8. This makes it easier to prevent the wire from breaking through the first tubular member 1.

[0023] 2, the distal end 1B of the first tubular member 1 is located more proximal than the distal end 2B of the second tubular member 2. This makes it easier for the catheter 91 to bend in the portion distal to the distal end 1B of the first tubular member 1.

[0024] 1 and 3, the proximal end 1A of the first tubular member 1 is located proximal to the proximal end 2A of the second tubular member 2. This allows the portion of the catheter 91 proximal to the proximal end 2A of the second tubular member 2 to have, for example, a double-tube structure (coaxial structure), which is different from the structure in which the first tubular member 1 and the second tubular member 2 distal to the proximal end 2A of the second tubular member 2 overlap in the radial direction Y, and allows different functions to be achieved.

[0025] 1, 2, and 3, the catheter 91 has an outer member 3 that extends in the longitudinal direction X and has a portion that contains at least a portion of the first tubular member 1 and at least a portion of the second tubular member 2. The outer member 3 can protect the first tubular member 1 and the second tubular member 2, and can also make it easier to prevent the wire from breaking through from inside the catheter 91.

[0026] The outer member 3 preferably contains at least one selected from the group consisting of polyethylene, polyurethane, polyurethane-based thermoplastic elastomer, styrene-based thermoplastic elastomer, polyamide elastomer, and polyamide, and more preferably at least one selected from the group consisting of polyurethane and polyamide elastomer.

[0027] As shown in FIG. 1 , the outer member 3 has a first region A1 extending in the longitudinal direction X distal to the proximal end 2A of the second tubular member 2, and a second region A2 extending in the longitudinal direction X and located distal to the first region A1. As shown in FIG. 4 , the ratio of the major axis A1l to the minor axis A1m in the cross section of the first region A1 taken in the radial direction Y is 1.0 to 1.1. As shown in FIG. 5 , the ratio of the major axis A2l to the minor axis A2m in the cross section of the second region A2 taken in the radial direction Y is 1.2 to 2.0. When the value of the major axis A1l / minor axis A1m of the first region A1 is 1.0 to 1.1, the catheter 91 is less likely to twist in a tortuous section within the body, making it easier to transmit a force from the proximal side to the distal side. On the other hand, when the value of the major axis A2l / minor axis A2m of the second region A2 distal to the first region A1 is 1.2 to 2.0, the catheter 91 can be easily curved along the shape of a tortuous portion inside the body. The value of the major axis A2l / minor axis A2m is preferably 1.2 to 1.9, more preferably 1.2 to 1.7, and even more preferably 1.2 to 1.5. It is sufficient that the outer member 3 has the first region A1 distal to the proximal end 2A of the second tubular member 2, and the first region A1 may be located distal to the proximal end 2A of the second tubular member 2. The length of the major axis A1l of the first region A1 is preferably 0.5 mm or more and 2.0 mm or less, and more preferably 0.7 mm or more and 1.6 mm or less.

[0028] In this specification, the major axis of each region in the cross section in the radial direction Y refers to the length of the longest line segment connecting two points on the outer edge of each region in the cross section in the radial direction Y and passing through the centroid. Furthermore, if the cross-sectional shape is a part of an ellipse described later, the major axis of the circumscribing imaginary ellipse is the major axis of the cross section in the radial direction Y. Furthermore, in this specification, the minor axis of each region in the cross section in the radial direction Y refers to the length of the shortest line segment connecting two points on the outer edge of each region in the cross section in the radial direction Y and passing through the centroid. Furthermore, if the cross-sectional shape is a part of an ellipse described later, the minor axis of the circumscribing imaginary ellipse is the minor axis of the cross section in the radial direction Y. Furthermore, if the shape of the outer edge of the cross section in the radial direction Y is circular, the major axis and the minor axis are the same length.

[0029] As shown in Figure 4, the shape of the outer edge A1e of the first region A1 in the cross section in the radial direction Y is preferably a circle or an ellipse, and more preferably a circle. This makes it difficult for the first region A1 to twist in a tortuous section inside the body, making it easier for the catheter 91 to transmit force from the proximal side to the distal side. The shape of the outer edge A1e of the first region A1 in the cross section in the radial direction Y may be a rounded polygon or the like. The first region A1 may have portions whose cross-sectional shapes in the radial direction Y are different from each other.

[0030] As shown in FIG. 5 , the shape of the outer edge A2e of the second region A2 in the cross section in the radial direction Y is preferably elliptical. This allows the second region A2 to easily bend along the shape of a meandering portion inside the body, and therefore the catheter 91 to easily bend along the shape of a meandering portion inside the body. Furthermore, for example, near the first opening 1E, the shape of the outer edge A2e of the second region A2 in the cross section in the radial direction Y is preferably a partial ellipse. The partial ellipse shape refers to the shape obtained by cutting out a portion of an ellipse. The shape of the outer edge A2e of the second region A2 in the cross section in the radial direction Y may be a rounded polygon or the like. The second region A2 may have portions whose cross-sectional shapes in the radial direction Y are different from each other.

[0031] 4 and 5, the area of ​​the region surrounded by the outer edge A1e in the radial Y cross section of the first region A1 is preferably larger than or equal to, and more preferably larger than, the area of ​​the region surrounded by the outer edge A2e in the radial Y cross section of the second region A2. This makes it easier to insert the catheter 91 into tortuous sections within the body. The area of ​​the region surrounded by the outer edge A1e in the radial Y cross section of the first region A1 is preferably 1.00 to 2.00 times, and more preferably 1.01 to 1.50 times, the area of ​​the region surrounded by the outer edge A2e in the radial Y cross section of the second region A2.

[0032] The major axis A21 of the second region A2 is preferably larger than or equal to the major axis A11 of the first region A1, and more preferably larger than the major axis A11 of the first region A1, which allows the second region A2 to easily transmit force from the proximal side to the distal side.

[0033] 4 and 16, the major axis A21 of the second region A2 may be smaller than the major axis A11 of the first region A1, which improves the flexibility of the second region A2.

[0034] 4 and 5 , the shortest distance in the radial direction Y from the outer edge A2e of the second region A2 of the outer member 3 to the outer edge 1e of the first tubular member 1 is preferably longer than or equal to the shortest distance from the outer edge A1e of the first region A1 of the outer member 3 to the outer edge 1e of the first tubular member 1, and more preferably longer than the shortest distance from the outer edge A1e to the outer edge 1e. This makes it difficult for the wire to break through the first tubular member 1 and the second region A2, even if the wire is inserted into a meandering portion of the second region A2. The shortest distance in the second region A2 is measured in a portion of the second region A2 whose cross-sectional shape in the radial direction Y is elliptical. The same applies to the shortest distance in the second region A2 below.

[0035] 4 and 16 , in the radial direction Y, the shortest distance from the outer edge A2e of the second region A2 of the outer member 3 to the outer edge 1e of the first cylindrical member 1 may be shorter than the shortest distance from the outer edge A1e of the first region A1 of the outer member 3 to the outer edge 1e of the first cylindrical member 1. In this case, the second region A2 in the vicinity of the first cylindrical member 1 is less likely to twist when inserted into the serpentine portion.

[0036] In the radial direction Y, the shortest distance from the outer edge A2e of the second region A2 of the outer member 3 to the outer edge 2e of the second tubular member 2 is preferably longer than or equal to the shortest distance from the outer edge A1e of the first region A1 of the outer member 3 to the outer edge 2e of the second tubular member 2, and more preferably longer than the shortest distance from the outer edge A1e to the outer edge 2e. This makes it difficult for the wire to break through the second tubular member 2 and the second region A2, even if the wire is inserted into a meandering portion of the second region A2. The shortest distance in the second region A2 is measured in a portion of the second region A2 whose cross-sectional shape in the radial direction Y is elliptical. The same applies to the shortest distance in the second region A2 below.

[0037] 4 and 16 , in the radial direction Y, the shortest distance from the outer edge A2e of the second region A2 of the outer member 3 to the outer edge 2e of the second cylindrical member 2 may be shorter than the shortest distance from the outer edge A1e of the first region A1 of the outer member 3 to the outer edge 2e of the second cylindrical member 2. In this case, the second region A2 in the vicinity of the second cylindrical member 2 is less likely to twist when inserted into the serpentine portion.

[0038] 1, the length of the second region A2 in the longitudinal direction X is preferably shorter than the length of the first region A1 in the longitudinal direction X. This makes it easier to insert the catheter 91 into a tortuous portion of the body. Specifically, the length of the first region A1 in the longitudinal direction X is preferably 1.1 to 30 times, and more preferably 1.2 to 20 times, the length of the second region A2 in the longitudinal direction X.

[0039] As shown in Figures 1 and 6, the outer member 3 has a third region A3 between the first region A1 and the second region A2 in the longitudinal direction X. The ratio of the major axis A3l to the minor axis A3m in the cross section of the third region A3 in the radial direction Y is preferably greater than 1.1 and less than 1.2. The third region A3 facilitates avoiding bending due to a sudden change in shape between the first region A1 and the second region A2. Therefore, it is more preferable that the first region A1 and the third region A3 are adjacent to each other in the longitudinal direction X, and that the third region A3 and the second region A2 are adjacent to each other in the longitudinal direction X. The length of the third region A3 in the longitudinal direction X is preferably 1 mm or more and 20 mm or less, and more preferably 3 mm or more and 10 mm or less.

[0040] It is preferable that the value of the major axis A3l / minor axis A3m of the third region A3 decreases from the proximal side to the distal side. This makes it easier to avoid bending due to a sudden change in shape between the first region A1 and the second region A2. It is preferable that the shape of the outer edge A3e of the third region A3 in a cross section in the radial direction Y is elliptical. This makes it easier to achieve the above-mentioned effects. The shape of the outer edge A3e of the third region A3 in a cross section in the radial direction Y may be a rounded polygon or the like.

[0041] 2, the distal end 3B of the outer member 3 is preferably located distal to the distal end 2B of the second tubular member 2. By arranging the outer member 3 made of a flexible material in this manner, the flexibility of the portion of the catheter 91 distal to the distal end 2B of the second tubular member 2 can be improved.

[0042] It is preferable that at least a portion of the inner surface of the outer member 3 is fixed to the outer surfaces of the first cylindrical member 1 and the second cylindrical member 2. This makes it difficult for the outer member 3 to twist or distort. Examples of the fixing method include welding, adhesion, etc.

[0043] The length in the longitudinal direction X from the distal end 3B of the outer member 3 to the distal end 2B of the second tubular member 2 is preferably greater than the maximum thickness of the second tubular member 2. This improves the flexibility of the catheter 91 in the vicinity of its distal end.

[0044] As shown in Figures 4, 5, 6, etc., the outer surfaces of the first tubular member 1 and the second tubular member 2 may not be in contact with each other, or may be in contact and fixed to each other. Examples of fixing methods include welding and adhesive bonding. When the outer surfaces of the first tubular member 1 and the second tubular member 2 are not in contact with each other, they are preferably fixed to each other via the resin of the outer member 3. Furthermore, as shown in Figures 4, 5, 6, etc., in the cross section of the catheter 91 in the radial direction Y, the shapes of the first lumen 1L and the second lumen 2L are preferably circular, elliptical, arcuate, or a combination thereof, and more preferably circular or elliptical. This makes the catheter 91 more easily bendable. Within the catheter 91, it is preferable that the first lumen 1L and the second lumen 2L are not in communication with each other. In the cross section of the radial direction Y, the first lumen 1L may have a larger area than the second lumen 2L, a smaller area than the second lumen 2L, or the same area as the second lumen 2L.

[0045] 2, the first tubular member 1 preferably has a first opening 1E communicating with the lumen 1L. The first opening 1E can be used as an entrance or exit for a wire.

[0046] 2, the second tubular member 2 preferably has a second opening 2E communicating with the lumen 2L. The second opening 2E can be used as an entrance or exit for the wire.

[0047] The outer member 3 preferably has a protruding portion 34 protruding in a direction away from the central axis 2C on the side closer to the first tubular member 1 in the radial direction Y than the distal end 1B of the first tubular member 1. This allows the tip of the wire inserted into the first tubular member 1 to be guided in a different direction from the tip of the wire inserted into the second tubular member 2, making it easier to treat bifurcation lesions, etc. This also makes it less likely for the wires to become tangled. The protruding portion 34 is preferably adjacent to the distal end 1B of the first tubular member 1. This makes it easier to guide the wire emerging from the first opening 1E by the protruding portion 34.

[0048] As shown in FIG. 2 , when a cross section X is defined as a cross section in the longitudinal direction X including the central axis 1C of the first tubular member 1 and the central axis 2C of the second tubular member 2, the protruding portion 34 preferably has a first inclined portion inclined away from the central axis 2C as it approaches the distal side, and a second inclined portion inclined toward the central axis 2C as it approaches the distal side. The second inclined portion is preferably located distal to the first inclined portion. The first inclined portion facilitates guiding the wire exiting the first opening 1E. The second inclined portion facilitates insertion into the body. The outer surfaces of the first inclined portion and the second inclined portion in the cross section X are preferably linear or curved, more preferably linear. When the outer surface of the second inclined portion in the cross section X is linear, the shape of the second inclined portion is a so-called tapered shape.

[0049] On the other hand, although not shown, the second cylindrical member 2 may not have a protruding portion protruding in a direction away from the central axis 2C on the side distal to the distal end 1B of the first cylindrical member 1 and closer to the first cylindrical member 1 in the radial direction Y. This reduces the outer diameter of the catheter 91 by the amount of the protruding portion, making the catheter 91 easier to bend.

[0050] The outer diameters of the first cylindrical member 1 and the second cylindrical member 2 are preferably 0.2 mm or more and 0.8 mm or less, and more preferably 0.3 mm or more and 0.7 mm or less, respectively, which makes it easier to insert the catheter 91 into the tortuous portion of the coronary artery.

[0051] As shown in FIG. 1 , a handle portion 8 is preferably disposed at the proximal end 1a of the first tubular member 1. Specifically, the proximal end 1a of the first tubular member 1 is preferably disposed within the handle portion 8. The practitioner can insert the catheter 91 into the body by grasping and pushing the handle portion 8. The outer shape of the handle portion 8 may be such that the practitioner can grasp it with their fingers. The handle portion 8 is preferably a resin molded product obtained by injection molding or the like. Examples of resins include polyolefin resins such as polyethylene and polypropylene, polycarbonate resins, and (meth)acrylic resins. Of these resins, transparent resins such as polycarbonate and polymethyl methacrylate are preferred. This makes it easier to see inside the handle portion 8 and facilitates wire insertion.

[0052] The proximal end 1A of the first tubular member 1 is preferably located within the handle portion 8. This can improve pushability.

[0053] The handle portion 8 preferably has an inner cavity that communicates with the inner cavity 1L of the first tubular member 1 and extends in the longitudinal direction X, and a wire can be inserted through this inner cavity.

[0054] As shown in FIGS. 1 and 3 , the catheter 91 preferably further includes an outer tubular member 4 extending in the longitudinal direction X. The outer tubular member 4 preferably has a lumen 4L extending in the longitudinal direction X, with a portion of the first tubular member 1 disposed in the lumen 4L. The outer tubular member 4 forms a double-tube structure (coaxial structure), protecting the first tubular member 1 while improving the transmission of pushing force. Specifically, the outer tubular member 4 preferably has a fixed portion fixed to the first tubular member 1 at its distal end and a non-fixed portion proximal to the fixed portion that is not fixed to the first tubular member 1. The non-fixed portion facilitates the release of force associated with inserting the wire into the first tubular member 1. Therefore, it is preferable that the non-fixed portion be longer than the fixed portion in the longitudinal direction X. This reduces the risk of the wire puncturing the first tubular member 1. The outer tubular member 4 also preferably has a fixed portion fixed to the handle portion 8 at its proximal end.

[0055] The outer cylindrical member 4 is preferably located proximal to the proximal end 2A of the second cylindrical member 2. This allows the outer diameter of the outer cylindrical member 4 to be reduced.

[0056] The outer tubular member 4 preferably contains the same resin as the outer member 3 or a harder resin, and more preferably is made of a harder resin. A harder resin can improve pushability. In addition, the distal end of the outer tubular member 4 and the proximal end of the outer member 3 are preferably fixed to each other.

[0057] 1 and 7, the outer cylindrical member 4 has a fourth region A4 extending in the longitudinal direction X proximally from the proximal end 2A of the second cylindrical member 2, and the ratio of the major axis A4l to the minor axis A4m in a cross section of the fourth region A4 in the radial direction Y is preferably 1.0 to 1.1. When the value of major axis A4l / minor axis A4m is 1.0 to 1.1, the catheter 91 is less likely to twist in a tortuous section inside the body, making it easier to transmit a force from the proximal side to the distal side.

[0058] The outer tubular member 4 may have a fourth region A4 proximal to the proximal end 2A of the second tubular member 2, and the fourth region A4 may be located proximal to the proximal end 2A of the second tubular member 2.

[0059] As shown in Figures 5 and 7, the major axis A2l of the second region A2 is preferably smaller than the major axis A4l of the fourth region A4. This allows the second region A2 to bend more easily around meandering sections in the body. The major axis A2l is preferably 0.99 times or less, and more preferably 0.98 times or less, of the major axis A4l. On the other hand, the major axis A2l is preferably 0.5 times or more, and more preferably 0.6 times or more, of the major axis A4l. This improves the pushability of the second region A2.

[0060] As shown in FIG. 1 , the length of the fourth region A4 in the longitudinal direction X is preferably longer than the sum of the length of the first region A1 in the longitudinal direction X and the length of the second region A2 in the longitudinal direction X. This improves the pushability of the catheter 91. In the longitudinal direction X, the length of the fourth region A4 is preferably at least twice the sum of the lengths of the first region A1 and the second region A2, and more preferably at least three times. On the other hand, this magnification is preferably no more than 14 times, and more preferably no more than 6 times. This allows the length of the catheter 91 to be reduced. The sum of the lengths of the first region A1 and the second region A2 in the longitudinal direction X is preferably no less than 5 cm and no more than 50 cm, and more preferably no less than 10 cm and no more than 40 cm.

[0061] As shown in FIGS. 1 and 8 , the outer member 3 has a fifth region A5 extending in the longitudinal direction X and located distal to the second region A2. The ratio of the major axis A5l to the minor axis A5m in the cross section of the fifth region A5 taken along the radial direction Y is preferably 1.0 to 1.1. Having the ratio of the major axis A5l / the minor axis A5m between 1.0 and 1.1 facilitates preventing deformation, such as twisting, near the distal end of the catheter 91. Therefore, the fifth region A5 preferably includes the distal end of the catheter 91. While the fifth region A5 is preferably adjacent to the second region A2 in the longitudinal direction X, other regions may exist between the fifth region A5 and the second region A2. The ratio of the major axis to the minor axis in the cross section of the other regions taken along the radial direction Y is preferably greater than 1.1 and less than 1.2. This facilitates avoiding bending due to sudden shape changes.

[0062] As shown in Figures 4 to 6, the outer member 3 preferably has a columnar body 5 extending in the longitudinal direction X and containing resin, with at least a portion of the first tubular member 1 and at least a portion of the second tubular member 2 being disposed within the columnar body 5. That is, at least a portion of the first tubular member 1 and at least a portion of the second tubular member 2 are preferably sealed by the columnar body 5 extending in the longitudinal direction X and containing resin. This makes it easier to maintain the shapes of the lumens 1L and 2L extending in the longitudinal direction X even when the catheter 91 is bent. The columnar body 5 preferably has at least a first region A1 and a second region A2, and further preferably has a third region A3 and / or a fifth region A5. For details of each region, please refer to the description of each region of the tubular outer member 3 described above. Note that the resin of the columnar body 5 may be present between the first tubular member 1 and the second tubular member 2.

[0063] The cylinder 5 preferably has an elliptical cylindrical portion, a cylindrical portion, or an elliptical cylindrical portion and a cylindrical portion. It is more preferable that the cylinder 5 has a plurality of elliptical cylindrical portions with different major axis / minor axis values. The plurality of elliptical cylindrical portions are preferably adjacent to each other in the longitudinal direction X. Each elliptical cylindrical portion may have a constant major axis / minor axis value, or may have a value that changes distally. Furthermore, when the cylinder 5 has an elliptical cylindrical portion and a cylindrical portion, it is preferable that the elliptical cylindrical portion and the cylindrical portion are adjacent to each other in the longitudinal direction X.

[0064] The columnar body 5 can be formed, for example, by arranging two or more tubes with different major axis / minor axis values ​​side by side in the longitudinal direction X, placing the first cylindrical member 1 and the second cylindrical member 2 inside these tubes while overlapping them in the radial direction Y, and heating and fusing these tubes to the first cylindrical member 1 and the second cylindrical member 2. Alternatively, the columnar body 5 can be formed by preparing a tube with a major axis / minor axis value of 1.0 to 1.1, placing the first cylindrical member 1 and the second cylindrical member 2 inside these tubes while overlapping them in the radial direction Y, and fusing the tube to the first cylindrical member 1 and the second cylindrical member 2 while heating the tube and sandwiching a portion of the tube between plates or the like from both radially inward sides of the tube. In this case, the second region A2 can also be formed by setting the major axis / minor axis value of the portion sandwiched between the plates or the like to 1.2 to 2.0. The same applies to the other regions.

[0065] 2, the first tubular member 1 may have a radiopaque marker 6A proximal to the proximal end of the first opening 1E and distal to a point 1 cm proximally from the proximal end of the first opening 1E, which makes it easier to grasp the position of the first opening 1E.

[0066] The second tubular member 2 may have an X-ray opaque marker 6B at a position distal to the distal end 1B of the first tubular member 1 and proximal to the distal end 2B of the second tubular member 2. This makes it easier to grasp the position of the curved part of the catheter 91 when inserting the catheter 91 into a tortuous part inside the body, thereby facilitating insertion.

[0067] The radiopaque marker is preferably ring-shaped. The radiopaque marker preferably contains a radiopaque material, and more preferably consists of a radiopaque material. The radiopaque material is preferably at least one selected from the group consisting of lead, barium, iodine, tungsten, gold, platinum, iridium, platinum-iridium alloy, stainless steel, titanium, cobalt-chromium alloy, palladium, bismuth, and tantalum.

[0068] 9, the catheter 91 preferably includes a linear member 11 that extends in the longitudinal direction X, is disposed in at least a first region A1 and a fourth region A4, and has a distal end 11B located within the first region A1, thereby improving pushability.

[0069] The linear member 11 preferably contains a metal, and more preferably is made of a metal. The metal is preferably stainless steel, nickel titanium, cobalt chrome, or an alloy thereof. This can further improve pushability.

[0070] The linear member 11 is preferably linear in shape. The linear member 11 is preferably a solid member without an internal cavity. This can further improve pushability. The number of linear members 11 included in the catheter 91 may be one, or two or more.

[0071] The linear member 11 preferably has a constant diameter portion 11U that extends in the longitudinal direction X and has a constant radial length. More preferably, the linear member 11 further has a tapered portion 11T that is located distal to the constant diameter portion 11U and that tapers distally.

[0072] Although not shown, the proximal end of the linear member 11 is preferably located within the handle portion 8. The proximal end of the linear member 11 is preferably fixed to the first tubular member 1, the handle portion 8, or the outer tubular member 4. This can further improve pushability.

[0073] Although not shown, the catheter 91 may further have a tip extending in the longitudinal direction X. The tip preferably has an inner lumen extending in the longitudinal direction X, and at least the distal end of the second tubular member 2 is preferably disposed within the inner lumen. This makes it easier for the tip and the second tubular member 2 to bend integrally.

[0074] It is preferable that at least a portion of the inner surface of the tip is fixed to the outer surface of the second cylindrical member 2. This makes it easier for the tip and the second cylindrical member 2 to bend integrally. Examples of the fixing method include welding and adhesion.

[0075] The chip preferably contains a flexible resin. The flexible resin preferably contains at least one selected from the group consisting of polyethylene, polyurethane, polyurethane-based thermoplastic elastomer, styrene-based thermoplastic elastomer, polyamide elastomer, and polyamide, and more preferably contains at least one selected from the group consisting of polyurethane and polyamide elastomer. The polyethylene is preferably low-density polyethylene having a specific gravity of 0.91 to 0.92.

[0076] The tip preferably has a region in which the ratio of the major axis to the minor axis in a cross section in the radial direction Y is 1.0 to 1.1. This region preferably includes the distal end of the tip. This makes it easier to prevent deformation, such as twisting, of the distal end of the tip. It is more preferable that the tip consists of this region.

[0077] The catheter 91 can be preferably used for treatment of narrowing or dilating blocked areas of passages such as blood vessels in the body, and can be preferably used for performing coronary intervention (PCI) for lesions at the bifurcation of coronary arteries.

[0078] A catheter according to the second embodiment will be described below with reference to Figures 10 to 15. Figure 10 is a side view of the catheter according to the second embodiment. Figure 11 is a longitudinal cross-sectional view of region R1 in Figure 10. Figure 12 is a longitudinal cross-sectional view of region R2 in Figure 10. Figure 13 is an A-A cross-sectional view of the catheter in Figure 10. Figure 14 is a B-B cross-sectional view of the catheter in Figure 10. Figure 15 is a CC cross-sectional view of the catheter in Figure 10. A detailed description of portions of the catheter according to the second embodiment that overlap with those of the catheter according to the first embodiment will be omitted.

[0079] The catheter according to the second embodiment is a catheter 92 having a first cylindrical member 1 extending in the longitudinal direction X, a second cylindrical member 2 extending in the longitudinal direction X and adjacent to the first cylindrical member 1 in the radial direction Y, and an outer member 3 extending in the longitudinal direction X and having a portion that encloses at least a portion of the first cylindrical member 1 and at least a portion of the second cylindrical member 2. For details of each part, please refer to the description of the catheter 91.

[0080] As shown in Figures 10 to 15, in a catheter 92, the outer member 3 is cylindrical and has a lumen 3L extending in the longitudinal direction X. Preferably, at least a portion of the first tubular member 1 and at least a portion of the second tubular member 2 are disposed in the lumen 3L. This protects the first tubular member 1 and the second tubular member 2, and the gaps between the outer member 3 and the first tubular member 1 and the gaps between the outer member 3 and the second tubular member 2 allow each tubular member to move to some extent, thereby dissipating the force of the wire from inside the catheter 92. As a result, it is easier to prevent the wire from breaking through. The distal end of the cylindrical outer member 3 is preferably fixed to the first tubular member 1 and the second tubular member 2. The proximal end of the cylindrical outer member 3 is preferably fixed to the first tubular member 1 and the second tubular member 2. This makes the cylindrical outer member 3 less likely to twist or kink. Examples of methods of fixation include welding and adhesive bonding.

[0081] The first region A1, second region A2, etc. of the cylindrical outer member 3 can be formed, for example, by joining two or more tubes with different major axis / minor axis values ​​in the longitudinal direction X. Alternatively, the second region A2 with a major axis / minor axis value of 1.2 to 2.0 may be formed by preparing a tube with a major axis / minor axis value of 1.0 to 1.1 and sandwiching the tube between plates or the like from both radially inward sides while heating a portion of the tube. The same applies to the other regions.

[0082] The cylindrical outer member 3 preferably has at least a first region A1 and a second region A2, and further has a third region A3 and / or a fifth region A5. For details of each region, please refer to the description of each region of the cylindrical outer member 3 described above.

[0083] In the catheter 92, the first tubular member 1 and the second tubular member 2 are preferably fixed to each other in the radial direction Y. Specifically, the outer surfaces of the first tubular member 1 and the second tubular member 2 are preferably fixed to each other in the radial direction Y. This makes the first tubular member 1 and the second tubular member 2 less likely to twist or distort. Examples of methods for fixing the first tubular member 1 and the second tubular member 2 include welding and adhesive bonding.

[0084] This application claims the benefit of priority based on Japanese Patent Application No. 2023-125557, filed on August 1, 2023. The entire contents of the specification of Japanese Patent Application No. 2023-125557, filed on August 1, 2023, are incorporated herein by reference.

[0085] DESCRIPTION OF SYMBOLS 1 First tubular member 1a Proximal end 1e Outer edge 1A Proximal end 1B Distal end 1C Central axis 1E First opening 1L Lumen 2 Second tubular member 2e Outer edge 2A Proximal end 2B Distal end 2C Central axis 2E Second opening 2L Lumen 3 Outer member 3B Distal end 3L Lumen 4 Outer tubular member 4L Lumen 5 Cylinder 6A, 6B Radiopaque marker 8 Handle portion 11 Linear member 11B Distal end 11U Constant diameter portion 11T Tapered portion 34 Raised portion 91, 92 Catheter A1 First region A1e Outer edge A1l Major diameter A1m Minor diameter A2 Second region A2e Outer edge A2l Major diameter A2m Minor diameter A3 Third region A3e Outer edge A3l Major diameter A3m Minor diameter A4 Fourth region A4l Major diameter A4m Minor diameter A5 Fifth region A5l Major diameter A5m Minor diameter X Longitudinal direction Y Radial direction

Claims

1. A catheter having a first tubular member extending in a longitudinal direction, a second tubular member extending in the longitudinal direction and radially adjacent to the first tubular member, and an outer member extending in the longitudinal direction and having a portion containing at least a portion of the first tubular member and at least a portion of the second tubular member, wherein a distal end of the first tubular member is located proximal to a distal end of the second tubular member, and a proximal end of the first tubular member is located proximal to a proximal end of the second tubular member, The catheter has an outer member having a first region extending in the longitudinal direction distal to the proximal end of the second tubular member, and a second region extending in the longitudinal direction and located distal to the first region, wherein a ratio of the major axis to the minor axis in the radial cross section of the first region is 1.0 to 1.1, and a ratio of the major axis to the minor axis in the radial cross section of the second region is 1.2 to 2.

0.

2. The catheter according to claim 1, wherein the shape of the outer edge of the first region in the radial cross section is a circle or an ellipse, and the shape of the outer edge of the second region in the radial cross section is an ellipse or a partial ellipse.

3. A catheter as described in claim 1 or 2, wherein the outer member has a third region between the first region and the second region in the longitudinal direction, and the ratio of the major axis to the minor axis in the radial cross section of the third region is greater than 1.1 and less than 1.

2.

4. A catheter as described in claim 1 or 2, wherein the length of the second region in the longitudinal direction is shorter than the length of the first region in the longitudinal direction.

5. A catheter as described in claim 1 or 2, wherein the area of ​​the region surrounded by the outer edge in the radial cross section of the first region is greater than or equal to the area of ​​the region surrounded by the outer edge in the radial cross section of the second region.

6. The catheter according to claim 1 or 2, wherein the major axis of the second region is greater than or equal to the major axis of the first region.

7. A catheter as claimed in claim 1 or 2, wherein the major axis of the second region is smaller than the major axis of the first region.

8. A catheter as described in claim 1 or 2, wherein in the radial direction, the shortest distance from the outer edge of the second region of the outer member to the outer edge of the first tubular member is longer than or the same as the shortest distance from the outer edge of the first region of the outer member to the outer edge of the first tubular member.

9. A catheter as described in claim 1 or 2, wherein the shortest distance in the radial direction from the outer edge of the second region of the outer member to the outer edge of the first tubular member is shorter than the shortest distance from the outer edge of the first region of the outer member to the outer edge of the first tubular member.

10. A catheter as described in claim 1 or 2, wherein in the radial direction, the shortest distance from the outer edge of the second region of the outer member to the outer edge of the second tubular member is longer than or the same as the shortest distance from the outer edge of the first region of the outer member to the outer edge of the second tubular member.

11. A catheter as described in claim 1 or 2, wherein the shortest distance in the radial direction from the outer edge of the second region of the outer member to the outer edge of the second tubular member is shorter than the shortest distance from the outer edge of the first region of the outer member to the outer edge of the second tubular member.

12. A catheter as described in claim 1 or 2, wherein the outer member is tubular and has an inner lumen extending in the longitudinal direction, and at least a portion of the first tubular member and at least a portion of the second tubular member are disposed in the inner lumen.

13. A catheter as described in claim 1 or 2, wherein the outer member has a columnar body extending in the longitudinal direction and containing resin, and at least a portion of the first tubular member and at least a portion of the second tubular member are disposed within the columnar body.

14. A catheter as described in claim 1 or 2, further comprising an outer tubular member extending in the longitudinal direction, the outer tubular member having an inner lumen extending in the longitudinal direction, and a portion of the first tubular member being disposed in the inner lumen.

15. The catheter of claim 14, wherein the outer tubular member is located proximal to the proximal end of the second tubular member.

16. A catheter as described in claim 14, wherein the outer tubular member has a fourth region extending in the longitudinal direction proximally from the proximal end of the second tubular member, and the ratio of the major axis to the minor axis in the radial cross section of the fourth region is 1.0 to 1.

1.

17. The catheter of claim 16, wherein the major axis of the second region is smaller than the major axis of the fourth region.

18. The catheter of claim 16, wherein the length of the fourth region in the longitudinal direction is greater than the sum of the length of the first region in the longitudinal direction and the length of the second region in the longitudinal direction.

19. The catheter of claim 16, further comprising a linear member extending in the longitudinal direction, disposed within at least the first region and the fourth region, and having a distal end located within the first region.

20. A catheter as described in claim 1 or 2, wherein the outer member has a fifth region extending in the longitudinal direction and located distal to the second region, and the ratio of the major axis to the minor axis in the radial cross section of the fifth region is 1.0 to 1.

1.

21. The catheter according to claim 1 or 2, wherein the first tubular member and the second tubular member are fixed to each other in the radial direction.

22. The catheter according to claim 1 or 2, wherein a handle portion is disposed at the proximal end of the first tubular member.