Catheter

Abstract

To provide a catheter that can be easily inserted into a meandering part in the body.SOLUTION: A catheter includes: a first cylindrical member; a second cylindrical member adjacent to the first cylindrical member in a radial direction; an outside cylindrical member having a stationary part including part of the first cylindrical member, which is fixed to the first cylindrical member, and a non-stationary part located more on a proximal side than the stationary part, which is not fixed to the first cylindrical member; a first linear member, at least part of which is disposed in the outside cylindrical member; and a second linear member, at least part of which is disposed in the outside cylindrical member. The first linear member is fixed to the non-stationary part of the outside cylindrical member or the first cylindrical member in at least a part more on a proximal side than the stationary part of the outside cylindrical member and more on a distal side than a middle point in a longitudinal direction of the non-stationary part. A distal end part of the second linear member is fixed at least to the stationary part of the outside cylindrical member.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] Catheters that can be inserted into blood vessels and 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, which includes 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 adjacent to the first tubular member in the radial direction, the distal end of the first tubular member being located proximal to the distal end of the second tubular member, the proximal end of the first tubular member being located proximal to the proximal end of the second tubular member, the first tubular member having a reinforcing part having an inner layer and a reinforcing member containing at least one selected from the group consisting of polytetrafluoroethylene and tetrafluoroethylene-perfluoroalkylvinylether copolymer, and the first tubular member having an extension part made of resin that does not contain the polytetrafluoroethylene, the tetrafluoroethylene-perfluoroalkylvinylether copolymer, and the reinforcing member, on the distal side of the distal end of the reinforcing part. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 255737 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 describes an embodiment in which the outer surface of the first tubular member of the catheter has a metal reinforcing wire, and describes that such an embodiment can improve the transmission of pushing force. The inventors' research has revealed that if multiple such linear members are fixed inside the catheter with their distal ends aligned in the longitudinal direction, the transmission of pushing force is improved, but the catheter becomes difficult to bend when inserted into a curved part inside the body, such as a coronary artery, making insertion difficult. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a catheter that is easy to insert into a curved part inside the body. [Means for solving the problem]

[0005] A catheter according to an embodiment of the present invention that can solve the above problems is as follows. [1] A first tubular member extending in a longitudinal direction; a second cylindrical member extending in the longitudinal direction and adjacent to the first cylindrical member in a radial direction; an outer tubular member extending in the longitudinal direction, containing a portion of the first tubular member, and having a fixed portion fixed to the first tubular member and a non-fixed portion located proximal to the fixed portion and not fixed to the first tubular member; a first linear member extending in the longitudinal direction and at least a portion of which is disposed within the outer cylindrical member; a second linear member extending in the longitudinal direction and at least a portion of which is disposed within the outer tubular member, a distal end of the first tubular member is located proximal to a distal end of the second tubular member; a proximal end of the first tubular member is located proximal to a proximal end of the second tubular member; the first linear member is fixed to the non-fixed portion of the outer tubular member or the first tubular member in at least a portion that is proximal to the fixed portion of the outer tubular member and distal to a midpoint in the longitudinal direction of the non-fixed portion, A catheter in which the distal end of the second linear member is fixed to at least the fixing portion of the outer tubular member.

[0006] The inventors' research has revealed that by fixing the first linear member to a portion proximal to the fixed portion of the outer tubular member and further fixing the distal end of the second linear member to the fixed portion of the outer tubular member, it is possible to improve the transmission of the pushing force between the portion proximal to the fixed portion of the outer tubular member and the portion distal to the fixed portion. Furthermore, it has been found that by positioning the distal end of the portion to which the first linear member is fixed proximal to the distal end of the portion to which the second linear member is fixed, the portion between these distal ends is easily curved appropriately when the catheter is pushed into a curved portion inside the body. These configurations make it easier to insert the catheter into a curved portion inside the body.

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

[19] . [2] The catheter described in [1], wherein the outer tubular member is located proximal to the proximal end of the second tubular member. [3] A catheter as described in [1] or [2], wherein the distal end of the second linear member is further fixed to the proximal end of the second tubular member. [4] A catheter described in any of [1] to [3], wherein the first linear member is fixed to the non-fixed portion of the outer tubular member in at least a portion of the portion distal to the midpoint. [5] A catheter described in any of [1] to [4], wherein the distal end of the first linear member is located proximal to the fixed portion of the outer tubular member and distal to the midpoint. [6] A catheter described in any of [1] to [5], wherein the second linear member is not fixed to the first tubular member and the outer tubular member, at least in a portion that is proximal to the fixed portion of the outer tubular member and distal to the midpoint. [7] In the radial cross section including the portion to which the first linear member is fixed, The catheter according to any one of [1] to [6], wherein a center of the first linear member, a center of the outer tubular member, and a center of the second linear member are not positioned on the same line. [8] A catheter described in any of [1] to [7], wherein the outer tubular member has a first portion which is on the side of the outer tubular member closer to the second tubular member in the radial direction and in which the first linear member and the second linear member are arranged. [9] A catheter as described in [8], wherein the first portion is at least a part of a region of the outer tubular member proximal to the fixed portion and distal to the midpoint in the longitudinal direction of the non-fixed portion.

[10] A catheter described in any of [1] to [9], wherein, in the radial cross section of the portion where the first linear member is fixed, the second linear member is closer to the second tubular member than the first linear member.

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

[10] , wherein in the radial cross section of the portion where the first linear member is fixed, the outer diameter of the first linear member is smaller than the outer diameter of the second linear member.

[12] The catheter described in any one of [1] to

[11] , wherein the outer diameter of the non-fixed portion of the outer tubular member is larger than the outer diameter of the fixed portion of the outer tubular member.

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

[12] , wherein the first linear member is a solid member having no lumen, and the second linear member is a solid member having no lumen.

[14] The catheter further includes an outer member extending in the longitudinal direction and positioned distal to the outer tubular member, The catheter according to any one of [1] to

[13] , wherein the outer member has a portion that contains a portion of the first tubular member and at least a portion of the second tubular member.

[15] The catheter described in

[14] , 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.

[16] The outer member has a columnar body extending in the longitudinal direction and including a resin, The catheter according to

[14] , wherein at least a portion of the first tubular member and at least a portion of the second tubular member are disposed within the cylindrical body.

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

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

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

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

[19] A proximal end of the first linear member is fixed to a proximal end of the first tubular member, a proximal end of the outer tubular member, or the handle portion; The catheter described in

[18] , wherein the proximal end of the second linear member is fixed to the proximal end of the first tubular member, the proximal end of the outer tubular member, or the handle portion. Effect of the Invention

[0008] According to the present invention, with the above-mentioned configuration, it is possible to provide a catheter that can be easily inserted into curved parts inside the body. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of a catheter according to an embodiment. [Diagram 2] FIG. 2 is a longitudinal cross-sectional view of region R1 of FIG. [Diagram 3] FIG. 3 is a longitudinal cross-sectional view of region R2 in FIG. [Figure 4] FIG. 4 is a cross-sectional view of the catheter of FIG. 1 taken along line AA. [Diagram 5] FIG. 5 is a cross-sectional view taken along line AA of a modification of the catheter of FIG. [Figure 6] FIG. 6 is a BB cross-sectional view of the catheter of FIG. [Figure 7] FIG. 7 is a CC cross-sectional view of the catheter of FIG. [Figure 8] FIG. 8 is a side view of a variation of the catheter of FIG. [Figure 9] FIG. 9 is a side view of a variation of the catheter of FIG. [Figure 10] FIG. 10 is a CC cross-sectional view of a modification of the catheter of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described in more detail below based on the following embodiment, but the present invention is not limited to the following embodiment, and can be modified as long as it meets the purpose described above and below, and all of these modifications are included in the technical scope of the present invention. In addition, in each drawing, the reference numerals of the components may be omitted for convenience, and in such cases, the specification and other drawings should be referred to. In addition, the dimensions of various components in the drawings may differ from the actual dimensions, since priority is given to helping understand the features of the present invention.

[0011] The catheter according to the embodiment includes 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, an outer tubular member extending in the longitudinal direction, containing a portion of the first tubular member and having a fixed portion fixed to the first tubular member and a non-fixed portion located proximal to the fixed portion and not fixed to the first tubular member, a first linear member extending in the longitudinal direction and at least a portion of which is disposed within the outer tubular member, and a second linear member extending in the longitudinal direction and at least a portion of which is disposed within the outer tubular member. and a second linear member fixed 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 linear member is fixed to the non-fixed portion of the outer tubular member or the first tubular member at least in a portion proximal to the fixed portion of the outer tubular member and distal to the midpoint in the longitudinal direction of the non-fixed portion, and the distal end of the second linear member is fixed to at least the fixed portion of the outer tubular member.

[0012] The inventors' research has revealed that by fixing the first linear member to a portion proximal to the fixed portion of the outer tubular member and further fixing the distal end of the second linear member to the fixed portion of the outer tubular member, it is possible to improve the transmission of the pushing force between the portion proximal to the fixed portion of the outer tubular member and the portion distal to the fixed portion. Furthermore, it has been found that by positioning the distal end of the portion to which the first linear member is fixed proximal to the distal end of the portion to which the second linear member is fixed, the portion between these distal ends is easily curved appropriately when the catheter is pushed into a curved portion inside the body. These configurations make it easier to insert the catheter into a curved portion inside the body.

[0013] A catheter according to an embodiment will be described below with reference to Figs. 1 to 10. Fig. 1 is a side view of a catheter according to an 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 AA cross-sectional view of the catheter in Fig. 1. Fig. 5 is an AA cross-sectional view of a modified example of the catheter in Fig. 1. Fig. 6 is a BB cross-sectional view of the catheter in Fig. 1. Fig. 7 is a CC cross-sectional view of the catheter in Fig. 1. Fig. 8 is a side view of a modified example of the catheter in Fig. 1. Fig. 9 is a side view of a modified example of the catheter in Fig. 1. Fig. 10 is a CC cross-sectional view of a modified example of the catheter in Fig. 1.

[0014] As shown in FIG. 1, FIG. 2, and FIG. 3, the catheter according to the 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. 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 guide wire into each of the lumen 1L and the lumen 2L, the catheter 91 can be guided in multiple directions, making it easier to insert the catheter 91 into various branching parts of the coronary artery, for example. In addition, by inserting a searching wire into the lumen 1L or the lumen 2L, it is easier to search for the entrance of a stenosis, which is a lesion. Of these, it is preferable to insert a searching wire into the lumen 1L.

[0015] Each of the first tubular member 1 and the second tubular member 2 preferably has one or more layers extending in the longitudinal direction X, and more preferably has multiple layers. The multiple layers preferably have an inner layer and an outer layer containing at least a part of the inner layer. The multiple layers may further have an intermediate layer located between the inner layer and the outer layer. The number of intermediate layers is not limited to one, and may be two or more. It is preferable that each of the multiple layers contains a material different from that of the adjacent layer. It is preferable that each of the inner layer of the first tubular member 1 and the inner layer of the second tubular member 2 contains at least one resin selected from the group consisting of polyolefin resins and fluorine-based resins. This can improve the slidability of the guide wire inserted into the first lumen 1L and the second lumen 2L. The polyolefin resin is preferably polyethylene, polypropylene, an ethylene-propylene copolymer, or a mixture thereof. The polyethylene is preferably high-density polyethylene having a specific gravity of 0.942 or more. The fluororesin is preferably polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkylvinylether 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 resin, polyester resin, polyurethane resin, polyolefin resin, fluorine resin, vinyl chloride resin, silicone 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, preferably the same resin, and more preferably the same resin.

[0016] The outer layer of the first cylindrical member 1 and the outer layer of the second cylindrical member 2 each preferably contain a flexible resin. When the outer layer contains a flexible resin, the catheter 91 becomes easier to bend. 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 a low-density polyethylene having a specific gravity of 0.91 to 0.92.

[0017] The Shore D hardness of the material of the outer layer is preferably smaller than or equal to the Shore D hardness of the material of the inner layer, and more preferably smaller, so that the catheter 91 can be easily curved. The Shore D hardness may be measured, for example, with a durometer type D according to ISO 7619.

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

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

[0020] The first cylindrical member 1 preferably includes a reinforcing member. This makes it easier to prevent the wire from breaking through the first cylindrical member 1. On the other hand, the second cylindrical member 2 preferably does not include a reinforcing member. This makes it easier to improve the flexibility of the second cylindrical member 2.

[0021] The reinforcing member is preferably a braided body in which wires are braided, a coil body in which wires are wound in a spiral shape, or a combination of these. This makes it easier to prevent the guide wire from breaking through the first tubular member 1. Of these, the braided body is more preferably the reinforcing member because it is easier to improve the rigidity. Examples of wires contained in the reinforcing member include metal wires and fibers. The metal wire preferably contains stainless steel, titanium, nickel-titanium alloy, cobalt-chromium alloy, tungsten alloy, or an alloy thereof. Of these, stainless steel is more preferable. The metal wire may be a single 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 mixture thereof. The fiber may be a monofilament or a multifilament. The reinforcing member may contain an X-ray impermeable material to make it easier to confirm the position of the first tubular member 1 under X-ray fluoroscopy or the like. 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 proximally relative to 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 a structure, for example a double tube structure (coaxial structure), 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, allowing different functions to be exhibited.

[0025] As shown in Figs. 1 and 3, the catheter 91 further has an outer tubular member 3 extending in the longitudinal direction X. The outer tubular member 3 contains a part of the first tubular member 1. Specifically, the outer tubular member 3 has an inner cavity 3L extending in the longitudinal direction X, and it is preferable that a part of the first tubular member 1 is disposed in the inner cavity 3L. The outer tubular member 3 can improve the transmission of the pushing force while protecting the first tubular member 1. The outer tubular member 3 and the first tubular member 1 can form a double tube structure (coaxial structure), which can reduce the risk of the catheter 91 breaking through when a wire is inserted into the inner cavity 1L of the first tubular member 1.

[0026] As shown in FIG. 1 and FIG. 3, the outer tubular member 3 has a fixed portion 3F fixed to the first tubular member 1, and a non-fixed portion 3G located proximal to the fixed portion 3F and not fixed to the first tubular member 1. The fixed portion 3F can prevent the outer tubular member 3 from coming off while improving the transmission of the pushing force. Examples of the fixing method include welding and adhesion. On the other hand, the non-fixed portion 3G is a portion of the outer tubular member 3 that is not fixed to the first tubular member 1 over the entire circumference in the circumferential direction, as shown in FIG. 4. The non-fixed portion 3G makes it easier for the first tubular member 1 to move, so that it is easier to release the force associated with the insertion of a guide wire or the like into the first tubular member 1. Therefore, it is preferable that the non-fixed portion 3G is longer than the fixed portion 3F in the longitudinal direction X. This can reduce the risk of the wire breaking through the first tubular member 1. In the longitudinal direction X, the length of the non-fixed portion 3G is preferably 50 to 200 times, and more preferably 100 to 150 times, the length of the fixed portion 3F. The length of the fixed portion 3F in the longitudinal direction X is preferably 1 to 10 mm. In addition, the outer tubular member 3 preferably has another fixed portion fixed to the handle portion 8 at its proximal end.

[0027] The outer tubular member 3 is preferably located proximal to the proximal end 2A of the second tubular member 2. Specifically, the distal end of the outer tubular member 3 is preferably located proximal to the proximal end 2A of the second tubular member 2. This allows the outer diameter of the outer tubular member 3 to be reduced.

[0028] The outer cylindrical 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. Among these, at least one selected from the group consisting of polyurethane and polyamide elastomer is more preferable. This can improve flexibility.

[0029] As shown in Figs. 1, 3, 4, and 5, the catheter 91 further includes a first linear member 11 extending in the longitudinal direction X and at least a part of which is disposed within the outer tubular member 3. The first linear member 11 is fixed to the non-fixed part 3G of the outer tubular member 3 or the first tubular member 1 at least a part of the first linear member 11 that is proximal to the fixed part 3F of the outer tubular member 3 and distal to the midpoint 3M in the longitudinal direction X of the non-fixed part 3G. By disposing the part 11F to which the first linear member 11 is fixed in this manner, the transmissibility of the pushing force in the part proximal to the fixed part 3F of the outer tubular member 3 can be improved. It is preferable that at least the distal part of the first linear member 11 is disposed within the outer tubular member 3, and it is more preferable that the distal part and the proximal part are disposed within the outer tubular member 3. This can improve the transmissibility of the pushing force from inside the outer tubular member 3. It is preferable that at least the distal end of the first linear member 11 is fixed to the non-fixed portion 3G of the outer tubular member 3 or the first tubular member 1. This can improve the transmittance of the pushing force by the first linear member 11.

[0030] As shown in Fig. 4, at least a part of the first linear member 11 distal to the midpoint 3M is fixed to the non-fixed portion 3G of the outer tubular member 3, thereby improving the transmissibility of the pushing force via the outer tubular member 3. On the other hand, as shown in Fig. 5, at least a part of the first linear member 11 distal to the midpoint 3M is fixed to the first tubular member 1, thereby improving the transmissibility of the pushing force via the first tubular member 1. The first linear member 11 may have a part fixed to the non-fixed portion 3G of the outer tubular member 3 and a part fixed to the first tubular member 1, or may have only one of the parts.

[0031] As shown in Fig. 1, the first linear member 11 is preferably fixed to the non-fixed portion 3G of the outer tubular member 3 or the first tubular member 1 at a portion distal to the midpoint 3M. In Fig. 1, reference numeral 11F indicates the portion to which the first linear member 11 is fixed. In this manner, the first linear member 11 has a fixed portion and an unfixed portion distal to the midpoint 3M, which makes it easier to achieve both improved pushing force and improved bendability. On the other hand, the first linear member 11 may be fixed to the first tubular member 1 over the entire portion distal to the midpoint 3M.

[0032] The distal end 11B of the first linear member 11 is preferably located proximal to the fixed portion 3F of the outer tubular member 3 and distal to the midpoint 3M. This makes it easier for the portion between the distal end 11B of the first linear member 11 and the distal end 12B of the second linear member 12 in the longitudinal direction X to bend, and improves the transmissibility of the pushing force distal to the midpoint 3M.

[0033] As shown in Figs. 1 and 3, the catheter 91 further includes a second linear member 12 extending in the longitudinal direction X and at least a portion of which is disposed within the outer cylindrical member 3. As shown in Figs. 3 and 6, the distal end 12b of the second linear member 12 is fixed to at least the fixed portion 3F of the outer cylindrical member 3. By fixing the distal end 12b of the second linear member 12 in this manner, it is possible to improve the transmission of the pushing force in the portion distal to the fixed portion 3F of the outer cylindrical member 3. Note that the reference numeral 12F in Fig. 1 indicates the portion to which the second linear member 12 is fixed. Although not shown, the entire second linear member 12 may be disposed within the outer cylindrical member 3.

[0034] 3 and 7, the distal end 12b of the second linear member 12 is preferably further fixed to the proximal end 2a of the second tubular member 2. By fixing the distal end 12b of the second linear member 12 to at least the fixing portion 3F of the outer tubular member 3 and the proximal end 2a of the second tubular member 2 in this manner, the transmittance of the pushing force from the second linear member 12 to the second tubular member 2 can be improved.

[0035] 3 and 7, the distal end 12b of the second linear member 12 is preferably further fixed to the proximal end 2a of the first tubular member 1 and the second tubular member 2. By positioning the distal end 12b of the second linear member 12 between the first tubular member 1 and the second tubular member 2 in this manner, the second linear member 12 is less likely to be exposed to the outside of the catheter 91, and the transferability of the pushing force to the first tubular member 1 and the second tubular member 2 can be improved.

[0036] 1, it is preferable that the second linear member 12 is not fixed to the first tubular member 1 and the outer tubular member 3 at least in a portion located proximal to the fixing portion 3F of the outer tubular member 3 and distal to the midpoint 3M. This makes it easier for the catheter 91 to bend in a portion located proximal to the fixing portion 3F and distal to the midpoint 3M. The second linear member 12 does not have to be fixed to the first tubular member 1 and the outer tubular member 3 over the entire portion proximal to the fixing portion 3F of the outer tubular member 3.

[0037] 4 and 5, in a cross section in the radial direction Y including the portion 11F to which the first linear member 11 is fixed (hereinafter may be referred to as "cross section Y"), it is preferable that the center 11N of the first linear member 11, the center 3N of the outer tubular member 3, and the center 12N of the second linear member 12 are not located on the same straight line. If the centers 11N, 12N, and 3N are located on the same imaginary line in cross section Y, the catheter 91 will be difficult to bend in the direction from one side of the imaginary line to the other side and from the other side to one side, but since they are not located on the same imaginary line, the catheter 91 will be easily bent in multiple directions.

[0038] 1, 3, 4, and 5, the outer cylindrical member 3 preferably has a first portion 3P1 in which the first linear member 11 and the second linear member 12 are arranged on a side 3R2 of the outer cylindrical member 3 that is closer to the second cylindrical member 2 in the radial direction Y. By arranging at least a part of each of the first linear member 11 and the second linear member 12 on the side 3R2 of the outer cylindrical member 3 that is closer to the second cylindrical member 2 in this manner, it is possible to easily transmit a pushing force from each linear member to the first cylindrical member 1 and the second cylindrical member 2.

[0039] As shown in FIG. 1, the first portion 3P1 is preferably at least a part of a region of the outer tubular member 3 that is proximal to the fixed portion 3F and distal to the midpoint 3M in the longitudinal direction X of the non-fixed portion 3G. The first portion 3P1 is located proximal to the fixed portion 3F, which makes it easier for the fixed portion 3F and its vicinity to bend. The first portion 3P1 is located distal to the midpoint 3M, which improves the transferability of the pushing force to the region distal to the midpoint 3M. In this case, as shown in FIG. 1, the outer tubular member 3 preferably has a second portion 3P2 on the side 3R1 of the outer tubular member 3 farther from the second tubular member 2 in the radial direction Y, in which the first linear member 11 and the second linear member 12 are arranged. The second portion 3P2 is preferably located proximal to the first portion 3P1. Because the outer tubular member 3 has such a first portion 3P1 and second portion 3P2, when the catheter 91 is inserted into a tortuous portion inside the body, the outer tubular member 3 becomes more likely to bend in the direction from the side 3R2 closer to the second tubular member 2 to the side 3R1 farther from the second tubular member 2.

[0040] 1, the outer cylindrical member 3 may have a third portion 3P3 in which the first linear member 11 or the second linear member 12 is disposed on a side 3R2 of the outer cylindrical member 3 that is closer to the second cylindrical member 2 in the radial direction Y, and the second linear member 12 or the first linear member 11 is disposed on a side 3R1 that is farther from the second cylindrical member 2. The third portion 3P3 is located between the first portion 3P1 and the second portion 3P2 in the longitudinal direction X, and can function as a transition portion between the first portion 3P1 and the second portion 3P2.

[0041] 8, the third portion 3P3 may be adjacent to the proximal side of the first portion 3P1 in the longitudinal direction X and extend up to the proximal end of the outer tubular member 3. This makes it easier for the operator to push in the handle portion 8 even if he or she changes the way he or she holds it.

[0042] 9, the first portion 3P1 may extend from a position proximal to a position distal to the midpoint 3M of the outer tubular member 3. This further improves the transmittance of the pushing force.

[0043] As shown in Figures 4 and 5, in a cross section in the radial direction Y (cross section Y) including a portion 11F to which the first linear member 11 is fixed, the second linear member 12 is preferably closer to the second cylindrical member 2 than the first linear member 11. In Figures 4 and 5, the upper side is the side closer to the second cylindrical member 2. By positioning the second linear member 12 closer to the second cylindrical member 2 than the first linear member 11, the transferability of the pushing force from the second linear member 12 to the second cylindrical member 2 can be improved.

[0044] The outer diameter of the non-fixed portion 3G of the outer cylindrical member 3 is preferably larger than the outer diameter of the fixed portion 3F of the outer cylindrical member 3. This makes it difficult for the wire to break through the first cylindrical member 1 and the non-fixed portion 3G of the outer cylindrical member 3 when the wire is inserted into the lumen 1L. The outer diameter of the non-fixed portion means the diameter of the circle when the cross-sectional shape of the non-fixed portion in the radial direction Y is a circle, and means the diameter of the circumscribing circle of the non-fixed portion when the cross-sectional shape is another shape. The outer diameter of the fixed portion means the diameter of the circle when the cross-sectional shape of the fixed portion in the radial direction Y is a circle, and means the diameter of the circumscribing circle of the fixed portion when the cross-sectional shape is another shape.

[0045] 4 and 5, in a cross section in the radial direction Y (cross section Y) of the portion 11F to which the first linear member 11 is fixed, the outer diameter of the first linear member 11 is preferably smaller than the outer diameter of the second linear member 12. This makes it easier for the portion to which the first linear member 11 is fixed to bend, and improves the transferability of the pushing force from the second linear member 12 to the first cylindrical member 1 and the second cylindrical member 2. The outer diameter of the linear member means the diameter of the circle when the cross-sectional shape of the linear member in the radial direction Y is a circle, and means the diameter of the circumscribing circle of the linear member when the cross-sectional shape is another shape.

[0046] The first linear member 11 and the second linear member 12 each preferably have a cross-sectional shape in the radial direction Y of a circle, an ellipse, a polygon, or a rounded polygon, and more preferably a circle. This can reduce the anisotropy of bending strength. It is preferable that the first linear member 11 is a solid member having no inner cavity, and the second linear member 12 is a solid member having no inner cavity. This improves the transmission of the pushing force.

[0047] As shown in FIG. 1, it is preferable that the first linear member 11 and the second linear member 12 each have a straight portion. The first linear member 11 and the second linear member 12 may each further have a curved portion or a bent portion. It is preferable that the curved portion or the bent portion is located proximal to the straight portion. It is preferable that the first linear member 11 and the second linear member 12 each are solid members having no lumen. This can further improve the pushing force. The number of linear members that the catheter 91 has is preferably two, but may be three or more, or may be five or less.

[0048] As shown in Fig. 3, the second linear member 12 preferably has a constant diameter portion 12U extending in the longitudinal direction X and having a constant radial length. More preferably, the second linear member 12 further has a tapered portion 12T located distal to the constant diameter portion 12U and tapered toward the distal side. The constant diameter portion 12U increases the pushing force, and the tapered portion 12T makes it easier for the second linear member 12 to bend. The tapered portion 12T is preferably located at least within the fixing portion 3F of the outer tubular member 3.

[0049] Although not shown, the first linear member 11 preferably has a constant diameter portion extending in the longitudinal direction X and having a constant radial length. More preferably, the first linear member 11 further has a tapered portion located distal to the constant diameter portion and tapered toward the distal side. The constant diameter portion improves the pushing force, and the tapered portion makes the first linear member 11 easier to bend. The tapered portion 12T of the second linear member 12 is preferably located distal to the tapered portion of the first linear member 11. This makes it easier to bend smoothly from the distal side to the proximal side.

[0050] 1, the proximal end 11a of the first linear member 11 is preferably fixed to the proximal end 1a of the first tubular member 1, the proximal end 3a of the outer tubular member 3, or the handle portion 8. The proximal end 12a of the second linear member 12 is preferably fixed to the proximal end 1a of the first tubular member 1, the proximal end 3a of the outer tubular member 3, or the handle portion 8. This improves the transferability of the pushing force. Examples of the manner of fixing include welding and adhesion.

[0051] The proximal ends of the first linear member 11 and the second linear member 12 are preferably located within the handle portion 8. This makes it easier to transmit a pushing force from the handle portion 8 to the first linear member 11 and the second linear member 12.

[0052] Each of the first linear member 11 and the second linear member 12 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 the pressing force.

[0053] 1, 2 and 3, the catheter 91 preferably further has an outer member 4 extending in the longitudinal direction X and positioned distal to the outer tubular member 3. The outer member 4 preferably has a portion that contains a part of the first tubular member 1 and at least a part of the second tubular member 2. The outer member 4 can protect the first tubular member 1 and the second tubular member 2, and can also easily prevent the wire from breaking through from inside the catheter 91.

[0054] The outer member 4 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. Among these, at least one selected from the group consisting of polyurethane and polyamide elastomer is more preferable. The outer tubular member 3 preferably contains the same resin as the outer member 4 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 3 and the proximal end of the outer member 4 are preferably fixed to each other.

[0055] As shown in FIG. 7, the outer member 4 has a columnar body 5 extending in the longitudinal direction X and containing a resin, and at least a part of the first cylindrical member 1 and at least a part of the second cylindrical member 2 are preferably disposed within the columnar body 5. That is, at least a part of the first cylindrical member 1 and the second cylindrical member 2 are preferably sealed by the columnar body 5 extending in the longitudinal direction X and containing a resin. This makes it easier to maintain the shapes of the first lumen 1L and the second lumen 2L extending in the longitudinal direction X even if the catheter 91 is curved. The columnar body 5 is preferably disposed at least between the proximal end 2A and the distal end 2B of the second cylindrical member 2. Note that the resin of the columnar body 5 may be present between the first cylindrical member 1 and the second cylindrical member 2.

[0056] The shape of the cylinder 5 is preferably a circular cylinder, an elliptical cylinder, or a rounded polygonal cylinder, and more preferably a circular cylinder or an elliptical cylinder, which makes it easier to insert the catheter 91 into the body.

[0057] The cylinder 5 may be formed by covering the first cylindrical member 1 and the second cylindrical member 2 overlapping in the radial direction Y with a resin tube and heating and welding them, or the cylinder 5 may be formed by injection molding the first cylindrical member 1 and the second cylindrical member 2 overlapping in the radial direction Y.

[0058] 2, the distal end 4B of the outer member 4 is preferably located distal to the distal end 2B of the second tubular member 2. By arranging the outer member 4 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.

[0059] At least a part of the inner surface of the outer member 4 is preferably fixed to the outer surface of the second cylindrical member 2. Furthermore, at least a part of the inner surface of the outer member 4 is more preferably fixed to the outer surface of the first cylindrical member 1. This makes it difficult for the outer member 4 to twist or twist. Examples of the manner of fixing include welding and adhesion.

[0060] It is preferable that the length in the longitudinal direction X from the distal end 4B of the outer member 4 to the distal end 2B of the second tubular member 2 is greater than the maximum thickness of the second tubular member 2. This can improve the flexibility of the catheter 91 in the vicinity of its distal end.

[0061] As shown in FIG. 10, the outer member 4 is cylindrical and has a lumen 4L extending in the longitudinal direction X, and at least a part of the first cylindrical member 1 and at least a part of the second cylindrical member 2 may be disposed in the lumen 4L. This makes it possible to protect the first cylindrical member 1 and the second cylindrical member 2, and also makes it possible to release the force of the guidewire and the like from the inside of the catheter 91, since the gap between the outer member 4 and the first cylindrical member 1 and the gap between the outer member 4 and the second cylindrical member 2 allow each cylindrical member to move to a certain extent, and as a result, it is possible to easily prevent the guidewire and the like from breaking through. The distal end of the cylindrical outer member 4 is preferably fixed to the first cylindrical member 1 and the second cylindrical member 2. Furthermore, the proximal end of the cylindrical outer member 4 is preferably fixed to the first cylindrical member 1 and the second cylindrical member 2. This makes it difficult for the cylindrical outer member 4 to twist or twist.

[0062] 2, the first tubular member 1 preferably has a first opening 1E communicating with the inner cavity 1L. The first opening 1E can be used as an entrance or exit for a wire.

[0063] 2, the second tubular member 2 preferably has a second opening 2E communicating with the inner cavity 2L. The second opening 2E can be used as an entrance or exit for the wire.

[0064] As shown in FIG. 2, the outer member 4 preferably has a protuberance 41 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 direction different from the tip of the wire inserted into the second tubular member 2, making it easier to treat bifurcation lesions and the like. This also makes it harder for the wires to become entangled. The protuberance 41 is preferably adjacent to the distal end 1B of the first tubular member 1. This makes it easier to guide the wire coming out of the first opening 1E by the protuberance 41.

[0065] As shown in FIG. 2, when a cross section in the longitudinal direction X including the central axis 1C of the first cylindrical member 1 and the central axis 2C of the second cylindrical member 2 is taken as the cross section X, the protuberance 41 preferably has a first inclined portion inclined in a direction away from the central axis 2C as it approaches the distal side, and a second inclined portion inclined so as to approach the central axis 2C as it approaches the distal side in the cross section X. The second inclined portion is preferably located distal to the first inclined portion. The first inclined portion makes it easier to guide the wire coming out of the first opening 1E. The second inclined portion makes it easier to insert into the body. The shape of the outer surface of the first inclined portion and the second inclined portion in the cross section X is preferably linear or curved, and 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.

[0066] On the other hand, although not shown, the outer member 4 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.

[0067] As shown in Fig. 7 and Fig. 10, 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 surface of the first tubular member 1 and the outer surface of 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, improving the transmission of the pushing force. Furthermore, this makes it easier to hold the distal end portion 12b of the second linear member 12 between the first tubular member 1 and the second tubular member 2. Examples of the manner of fixing include welding and adhesion.

[0068] 7, it is preferable that the first tubular member 1 and the second tubular member 2 are each fixed to the outer member 4. Specifically, it is preferable that the outer surface of the first tubular member 1 and the outer surface of the second tubular member 2 are each fixed to the inner surface of the outer member 4. This makes the first tubular member 1 and the second tubular member 2 less likely to twist or distort, improving the transmittance of the pushing force.

[0069] Although not shown, the first tubular member 1 and the second tubular member 2 do not have to be fixed to each other in the radial direction Y. For example, in the case where the outer member 4 is cylindrical as shown in FIG. 10, if the first tubular member 1 and the second tubular member 2 are not fixed to each other in the radial direction Y, it is possible to easily release the force caused by the insertion of the wire into the first tubular member 1 or the second tubular member 2. In addition, the first tubular member 1 and the second tubular member 2 do not have to be fixed to the outer member 4. This makes it possible to easily release the force caused by the insertion of the wire into the first tubular member 1 or the second tubular member 2.

[0070] The outer diameters of the first tubular member 1 and the second tubular 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 curved portion of the coronary artery blood vessel.

[0071] As shown in FIG. 1, a handle portion 8 is preferably disposed at the proximal end 1a of the first cylindrical member 1. Specifically, the proximal end 1a of the first cylindrical member 1 is preferably disposed within the handle portion 8. The practitioner can insert the catheter 91 into the body by gripping and pushing the handle portion 8. The outer shape of the handle portion 8 may be such that the practitioner can grip it with his / her 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. Among these resins, transparent resins such as polycarbonate and polymethyl methacrylate are preferable. This makes it easier to see inside the handle portion 8, making it easier to insert the wire.

[0072] The proximal end 1A of the first tubular member 1 is preferably located within the handle portion 8. This can improve the pushing force.

[0073] 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. A wire can be inserted through this inner cavity.

[0074] 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 away from the proximal end of the first opening 1E, which makes it easier to grasp the position of the first opening 1E.

[0075] The second tubular member 2 may have an X-ray impermeable 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 curved part inside the body, making insertion easier.

[0076] The radiopaque marker is preferably ring-shaped. The radiopaque marker preferably contains a radiopaque material, and more preferably is made 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, and tantalum.

[0077] Although not shown, the catheter 91 may further have a tip extending in the longitudinal direction X. It is preferable that the tip has an inner cavity extending in the longitudinal direction X, and that at least the distal end of the second tubular member 2 is disposed within the inner cavity. This makes it easier for the tip and the second tubular member 2 to bend integrally.

[0078] At least a part of the inner surface of the tip is preferably 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 manner of fixing include welding and adhesion.

[0079] 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 a low-density polyethylene having a specific gravity of 0.91 to 0.92.

[0080] The catheter 91 can be preferably used for treatment of dilating a stenosed or blocked portion of a passageway such as a blood vessel in the body, and can be preferably used for performing a percutaneous coronary intervention (PCI) for a bifurcation lesion of a coronary artery. [Explanation of symbols]

[0081] 1 First cylindrical member 1a Proximal end 1A proximal end 1B Distal end 1C center axis 1E 1st opening 1L lumen 2 Second cylindrical member 2a Proximal end 2A Proximal End 2B Distal end 2C center axis 2E 2nd opening 2L lumen 3. Outer cylindrical member 3a Proximal end 3F Fixed part 3G non-fixed part 3L lumen 3M midpoint 3N center 3P1 Part 1 3P2 2nd part 3P3 3rd part 3R1: Side farther from the second cylindrical member 3R2 Side closer to the second cylindrical member 4 Outer member 4L lumen 5 pillars 6A, 6B Radiopaque markers 8 Handle 11 First linear member 11a Proximal end 11B Distal end 11F Fixed part 11N center 12 Second linear member 12a Proximal end 12b Distal end 12F Fixed part 12N center 12T tapered section 12U constant diameter section 41 Ridge 91 Catheter X Longitudinal direction Y radial direction

Claims

1. A first tubular member extending in a longitudinal direction; a second cylindrical member extending in the longitudinal direction and adjacent to the first cylindrical member in a radial direction; an outer tubular member extending in the longitudinal direction, containing a portion of the first tubular member, and having a fixed portion fixed to the first tubular member, and a non-fixed portion located proximal to the fixed portion and not fixed to the first tubular member; a first linear member extending in the longitudinal direction and at least a portion of which is disposed within the outer cylindrical member; a second linear member extending in the longitudinal direction and at least a portion of which is disposed within the outer tubular member, a distal end of the first tubular member is located proximal to a distal end of the second tubular member; a proximal end of the first tubular member is located proximal to a proximal end of the second tubular member; the first linear member is fixed to the non-fixed portion of the outer tubular member or the first tubular member in at least a portion that is proximal to the fixed portion of the outer tubular member and distal to a midpoint in the longitudinal direction of the non-fixed portion, A catheter in which the distal end of the second linear member is fixed to at least the fixing portion of the outer tubular member.

2. The catheter of claim 1 , wherein the outer tubular member is located proximal to the proximal end of the second tubular member.

3. The catheter according to claim 1 or 2, wherein the distal end of the second linear member is further fixed to a proximal end of the second tubular member.

4. The catheter according to claim 1 or 2, wherein the first linear member is fixed to the non-fixed portion of the outer tubular member in at least a portion of the portion distal to the midpoint.

5. The catheter according to claim 1 or 2, wherein the distal end of the first linear member is located proximal to the fixing portion of the outer tubular member and distal to the midpoint.

6. 3. The catheter according to claim 1, wherein the second linear member is not fixed to the first tubular member and the outer tubular member, at least in a portion that is proximal to the fixing portion of the outer tubular member and distal to the midpoint.

7. In the radial cross section including the portion to which the first linear member is fixed, The catheter according to claim 1 or 2, wherein a center of the first linear member, a center of the outer tubular member, and a center of the second linear member are not positioned on the same line.

8. The catheter according to claim 1 or 2, wherein the outer tubular member has a first portion which is on the side of the outer tubular member closer to the second tubular member in the radial direction and in which the first linear member and the second linear member are arranged.

9. The catheter according to claim 8 , wherein the first portion is at least a part of a region of the outer tubular member that is proximal to the fixed portion and distal to the midpoint in the longitudinal direction of the non-fixed portion.

10. The catheter according to claim 1 or 2, wherein in the radial cross section of the portion to which the first linear member is fixed, the second linear member is closer to the second tubular member than the first linear member.

11. The catheter according to claim 10, wherein an outer diameter of the first linear member is smaller than an outer diameter of the second linear member in the radial cross section of the portion to which the first linear member is fixed.

12. The catheter according to claim 1 or 2, wherein an outer diameter of the non-fixed portion of the outer tubular member is larger than an outer diameter of the fixed portion of the outer tubular member.

13. 3. The catheter according to claim 1, wherein the first linear member is a solid member having no lumen, and the second linear member is a solid member having no lumen.

14. The catheter further includes an outer member extending in the longitudinal direction and positioned distal to the outer tubular member, The catheter according to claim 1 or 2, wherein the outer member has a portion that contains a portion of the first tubular member and at least a portion of the second tubular member.

15. The catheter of claim 14, 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.

16. the outer member has a columnar body extending in the longitudinal direction and including a resin, The catheter of claim 14 , wherein at least a portion of the first tubular member and at least a portion of the second tubular member are disposed within the cylinder.

17. 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.

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

19. a proximal end portion of the first linear member is fixed to a proximal end portion of the first tubular member, a proximal end portion of the outer tubular member, or the handle portion; The catheter according to claim 18, wherein the proximal end of the second linear member is fixed to the proximal end of the first tubular member, the proximal end of the outer tubular member, or the handle portion.

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