Catheter

Abstract

To provide a catheter that allows the tip of a sheath tube to be easily checked under radioscopy.SOLUTION: A catheter 10 (antegrade catheter 18) can advance along a blood vessel of a living body and includes a tubular first catheter body 24 having a first lumen 22, and a marker 26 having a radiopaque material arranged at the tip 24a of the first catheter body. The marker includes a stripe part 32a parallel to an extending direction of the first lumen.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a catheter to be inserted into a lumen of a living body. [Background technology]

[0002] Patent Document 1 discloses a sheath introducer that guides a catheter when it is introduced into a blood vessel. The sheath introducer has a tubular sheath tube with three contrast-enhanced sections at the tip of the sheath tube. The three contrast-enhanced sections are spaced apart from one another in the circumferential direction of the sheath tube and are striped, each extending in the longitudinal direction of the sheath tube. When the sheath tube is inserted into a blood vessel, the position of the tip of the sheath tube can be confirmed by visually viewing the contrast-enhanced sections in an image under fluoroscopy. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-229812 Summary of the Invention [Problem to be solved by the invention]

[0004] The distal end of the sheath tube in Patent Document 1 has an outer peripheral surface tapered toward the distal end. When checking the distal end of the sheath tube under radioscopy, medical personnel view it from a direction perpendicular to the longitudinal direction of the sheath tube. At this time, the three contrast regions are displayed in an oblique (tapered) shape along the outer peripheral surface of the distal end.

[0005] Therefore, when inserting a guidewire into the distal opening of the sheath tube while viewing the radiographic image, it is difficult to align the guidewire straight with the distal end of the sheath tube and insert it using the three diagonally displayed contrast areas as a guide. To align the distal end of the sheath tube and the guidewire, medical professionals must view radiographic images from various angles, which increases the work time and poses the problem of increased radiation exposure for medical professionals and patients.

[0006] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0007] (1) A first aspect of the present invention is a catheter that can be inserted into a lumen of a living body and advanced along the lumen, comprising a tubular catheter body having a lumen, and a marker that includes a radiopaque material and is positioned at the tip of the catheter body, the marker having a stripe portion that is parallel to the extension direction of the lumen.

[0008] With this catheter, the striped portion of the marker and the lumen are arranged parallel to each other, so that when inserting a guidewire into the lumen from the distal end of the catheter body under radioscopy, the guidewire can be easily coaxially aligned with the catheter body while visually checking the striped portion, and the guidewire can be inserted into the lumen of the catheter body. Because the guidewire can be easily aligned with the catheter body, radiation exposure to medical personnel and living bodies during work under radioscopy can be reduced.

[0009] (2) In the catheter described in (1) above, the distal end of the catheter body may have a bent portion at a position a predetermined distance away from the most distal end of the catheter body in the proximal direction, and the striped portion may extend at least to the bent portion.

[0010] With this configuration, even if the distal end of the catheter body has a bent portion, the guide wire can be easily inserted by coaxially aligning it with the stripe portion provided parallel to the lumen.

[0011] (3) In the catheter described in (1) above, the distance between the most distal end of the marker and the most distal end of the catheter body in the axial direction of the catheter body may be 0.5 mm or less.

[0012] With this configuration, the axial distance between the most distal end of the marker placed at the tip of the catheter and the most distal end of the catheter body is 0.5 mm or less, so that the position of the catheter tip can be accurately confirmed under radioscopy when the catheter is advanced along the lumen of the living body.

[0013] (4) In the catheter described in (1) above, the marker may have a ring portion that is formed in an annular shape along the circumferential direction of the catheter body and that constitutes the most distal end of the marker.

[0014] With this configuration, by visually checking the ring portion under radioscopy, the most distal end of the marker can be more easily and accurately confirmed, and the distal end position of the catheter can be confirmed with high precision.

[0015] (5) In the catheter according to any one of (1) to (4) above, the catheter may be an antegrade catheter that advances along the lumen toward the peripheral side of the living body.

[0016] With this configuration, when inserting the tip of a retrograde catheter into the tip of an antegrade catheter, the insertability of the retrograde catheter can be improved by inserting a guide wire inserted into the retrograde catheter along the striped portion of the marker.

[0017] (6) A second aspect of the present invention is a method for treating a lesion in a lumen using an antegrade catheter that advances along a lumen of a living body toward the peripheral side of the living body and a retrograde catheter that advances along the lumen toward the central side of the living body, wherein the antegrade catheter comprises a tubular first catheter body having a first lumen, and a marker that includes a radiopaque material and is disposed at a distal end of the first catheter body, the marker having a stripe portion that is parallel to the extending direction of the first lumen, and the retrograde catheter comprises a second The treatment method includes a tubular second catheter body having a lumen, and includes the steps of: advancing the antegrade catheter toward the peripheral side within the lumen of the living body; advancing the retrograde catheter with a guidewire inserted through the second lumen toward the central side; and inserting the tip of the guidewire into the first lumen while checking the positions of the striped portion of the marker and the guidewire under radioscopy, and inserting the tip of the retrograde catheter into the tip of the antegrade catheter. [Effects of the Invention]

[0018] According to the present invention, in the catheter, the striped portion of the marker and the lumen are arranged parallel to each other, so that when a guidewire is inserted into the lumen from the distal end of the catheter body under radioscopy, the guidewire and the catheter body can be easily coaxially aligned while visually checking the striped portion, and the guidewire can be inserted into the lumen of the catheter body. Because the guidewire and the catheter body can be easily aligned, it is possible to reduce the amount of radiation exposure to the living body when performing procedures under radioscopy. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a plan view showing the overall configuration of a catheter according to an embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged plan view showing the distal end of the antegrade catheter of FIG. [Figure 3]FIG. 3 is a front view of the distal end of the antegrade catheter of FIG. 2. [Figure 4] 4A to 4D are explanatory diagrams showing the manufacturing process when manufacturing a marker. [Figure 5] FIG. 5 is an explanatory diagram showing a state in which the tip of the antegrade catheter has been delivered to the upstream end of the lesion and the tip of the retrograde catheter has advanced into the lesion. [Figure 6] FIG. 6 is an explanatory diagram showing a state in which a guidewire is being inserted into the distal end of an antegrade catheter. [Figure 7] FIG. 7 is an explanatory diagram showing the state in which the tip of a retrograde catheter is inserted into the tip of an antegrade catheter at the lesion site. [Figure 8] FIG. 8 is a plan view showing the overall configuration of a catheter according to a modified example that does not have a bending portion. DETAILED DESCRIPTION OF THE INVENTION

[0020] 1, a catheter 10 according to this embodiment is used, for example, to treat a lesion 16 (such as a stenosis or occlusion) that has occurred in a blood vessel 14 of a living body 12. Specifically, the catheter 10 is used in lower limb vascular treatment, in which a CTO 16a (chronic total occlusion, lesion 16) that has occurred in a blood vessel 14 of the lower limb of the living body 12 is treated by an antegrade approach. Note that the catheter 10 may also be used to treat a lesion 16 in a lumen other than a blood vessel 14, for example, in a biological organ such as a bile duct, trachea, esophagus, urethra, or other organ.

[0021] The catheter 10 can be inserted into a blood vessel 14 of a living body 12 and advanced along the blood vessel 14. The catheter 10 is used, for example, as an antegrade catheter 18 used in an antegrade approach in lower limb vascular treatment. Hereinafter, the catheter 10 will also be referred to as the antegrade catheter 18. In lower limb vascular treatment, the distal end 36a of a retrograde catheter 20 used in a retrograde approach can be inserted into the distal end 24a of the antegrade catheter 18 (see FIG. 7).

[0022] The antegrade catheter 18 is a catheter that advances along the blood vessels 14 of the living body 12 toward the peripheral side of the living body 12 (toward the ankle, in the direction of arrow A) in treatment of the blood vessels in the lower limbs.

[0023] As shown in FIG. 2, the antegrade catheter 18 includes a tubular first catheter body 24 having a first lumen 22 and a marker 26 disposed at a distal end 24 a of the first catheter body 24 .

[0024] The first catheter body 24 is formed from a flexible resin material. Specifically, the first catheter body 24 is made of a resin material with a certain degree of flexibility, such as polyolefins such as polyethylene, polypropylene, and ethylene-propylene copolymer; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polystyrene; polyvinyl chloride; polyurethane; polyamide; or various elastomers such as polyolefin elastomers, polyester elastomers, polyurethane elastomers, and polyamide elastomers. These materials may be blended, layered, or arranged in multiple axial layers, or a reinforcement may be provided. The first lumen 22 is disposed inside the first catheter body 24. The first lumen 22 extends along the first catheter body 24. Because the antegrade catheter 18 is used to treat a CTO 16a, the distal end 24a of the first catheter body 24 is not made of a soft material such as rubber (elastomer) but has a hardness suitable for treating a CTO 16a.

[0025] As shown in Fig. 1, the outer peripheral surface of the distal end portion 24a of the first catheter body 24 is tapered, with the diameter decreasing toward the distal end (direction of arrow A) of the first catheter body 24. The distal end portion 24a of the first catheter body 24 has a bent portion 28. The bent portion 28 is located at a position a predetermined distance away from the distal end 24b of the first catheter body 24 in the proximal end direction (direction of arrow B in Fig. 1). The bent portion 28 causes the distal end portion 24a and the proximal end of the first catheter body 24 to be inclined relative to each other.

[0026] 2, the marker 26 includes a cylindrical support 26a and an imaging portion 26b disposed on the support 26a. The marker 26 enables the distal end position (leading end 24b) of the antegrade catheter 18 to be visualized under X-ray (radiation) imaging within the living body 12. The marker 26 is disposed at the distal end 24a of the first catheter body 24.

[0027] The support 26a is formed into a cylindrical shape from a transparent sheet-like film 44. The support 26a is made of a resin material that is transmissive to radiation. The support 26a is embedded inside the distal end 24a of the first catheter body 24. The support 26a has a predetermined length along the extension direction of the first catheter body 24.

[0028] The imaging portion 26b includes a radiopaque material (e.g., gold, platinum, tungsten, or a mixture thereof, etc.) and is disposed inside the support 26a. The imaging portion 26b is, for example, laminated on the sheet-like support 26a and covered by the support 26a.

[0029] The contrast imaging section 26b has a stripe section 32a extending in the axial direction of the support 26a, and a ring section 32b disposed at the tip of the stripe section 32a.

[0030] The stripe portion 32a is made of a wire extending from the tip to the base end of the support 26a. A plurality of stripe portions 32a are provided in the circumferential direction of the support 26a. The stripe portions 32a are equally spaced apart from one another in the circumferential direction of the support 26a. A case where four stripe portions 32a are provided will be described below.

[0031] When the marker 26 is placed at the distal end 24a of the first catheter body 24, each of the multiple striped portions 32a is parallel to the extension direction of the first lumen 22 (the direction of arrows A and B). The thickness of the striped portion 32a in the radial direction of the first catheter body 24 is constant along the striped portion 32a. The distal end of the striped portion 32a extends to the ring portion 32b. The proximal end of the striped portion 32a extends at least to the bent portion 28. In this embodiment, the striped portion 32a extends further proximally than the bent portion 28.

[0032] The ring portion 32b is disposed at the most distal end 26c of the marker 26. The ring portion 32b constitutes the distal end of the marker 26. The ring portion 32b is formed from a wire in a ring shape. The ring portion 32b is disposed along the circumferential direction of the support 26a. The ring portion 32b is connected to the distal end of each stripe portion 32a. The ring portions 32b connect the multiple stripe portions 32a together. When the marker 26 is disposed at the distal end 24a of the first catheter body 24, the ring portion 32b is disposed along the circumferential direction of the first catheter body 24.

[0033] The distal end portion of the marker 26 has a leading end 26c that is located closest to the distal end (in the direction of arrow A). The leading end 26c of the marker 26 is the distal end of the ring portion 32b. The leading end 26c of the marker 26 is located closer to the proximal end (in the direction of arrow B) than the leading end 24b of the first catheter main body 24. In the axial direction of the first catheter main body 24 (in the direction of arrows A and B), the axial distance L between the leading end 26c of the marker 26 and the leading end 24b of the first catheter main body 24 is 0.5 mm or less. In other words, the leading end 26c of the marker 26 is located within 0.5 mm toward the proximal end (in the direction of arrow B) from the leading end 24b of the first catheter main body 24. The leading end 26c (ring portion 32b) of the marker 26 is not exposed to the outside from the leading end 24b of the first catheter main body 24.

[0034] 1, the proximal end of the first catheter body 24 is provided with a first hub 30. The first hub 30 is cylindrical. The proximal end of the first hub 30 is open.

[0035] Next, a retrograde catheter 20 used in lower limb vascular treatment will be described. As shown in Fig. 1, in lower limb vascular treatment, the retrograde catheter 20 advances along a blood vessel 14 of a living body 12 toward the central side of the living body 12 (toward the heart, in the direction of arrow B). When the retrograde catheter 20 advances toward the central side, the distal end 36a of the retrograde catheter 20 can be inserted into the distal end 24a of the antegrade catheter 18 (see Fig. 7).

[0036] The retrograde catheter 20 has a second tubular catheter body 36 having a second lumen 34 .

[0037] The second catheter body 36 is formed from a flexible resin material. Specifically, the second catheter body 36 is made of a resin material with a certain degree of flexibility, such as polyolefins (e.g., polyethylene, polypropylene, ethylene-propylene copolymer), polyesters (e.g., polyethylene terephthalate, polybutylene terephthalate), polystyrene, polyvinyl chloride, polyurethane, polyamide, or various elastomers (e.g., polyolefin elastomers, polyester elastomers, polyurethane elastomers, polyamide elastomers), and the like. These materials may be blended, layered, or arranged in multiple axial layers, or a reinforcing member may be provided. The diameter of the second catheter body 36 is smaller than the diameter of the first catheter body 24. The second lumen 34 is disposed inside the second catheter body 36. The second lumen 34 extends along the second catheter body 36. The second lumen 34 is a passageway through which a guidewire 38 can be inserted. Since the retrograde catheter 20 is used to treat a CTO 16a, the tip portion 36a of the second catheter body 36 is not made of a soft material such as rubber (elastomer material) but has a hardness suitable for treating a CTO 16a.

[0038] The distal end 36a of the second catheter body 36 is tapered, the diameter of which decreases toward the distal end (direction of arrow B) of the second catheter body 36. The distal end 36a of the second catheter body 36 is the end that faces the direction of advancement (direction of arrow B) when the retrograde catheter 20 is inserted into and advanced through the blood vessel 14. In other words, the distal end 36a of the second catheter body 36 gradually tapers toward the most distal end 36b (direction of the distal end, direction of arrow B).

[0039] A radiopaque marker (not shown) is disposed at the distal end 36a of the second catheter body 36. The radiopaque marker contains a radiopaque material and enables the distal end position of the retrograde catheter 20 to be visualized in the living body 12 under X-ray (radiation) imaging.

[0040] The guidewire 38 is a wire made of a metallic material. The guidewire 38 is movably inserted through the second lumen 34 of the second catheter body 36. The tip portion 38a of the guidewire 38 can protrude distally (toward the central side, in the direction of arrow B) from the foremost end 36b of the second catheter body 36. The tip portion 38a of the guidewire 38 advances through the blood vessel 14 toward the central side (in the direction of arrow B) ahead of the tip portion 36a of the second catheter body 36. The retrograde catheter 20 is guided through the blood vessel 14 by the guidewire 38.

[0041] The proximal end of the second catheter body 36 is provided with a second hub 40. The second hub 40 is cylindrical. The proximal end of the second hub 40 is open. A guide wire 38 can be inserted into the second lumen 34 through the second hub 40.

[0042] Next, a method for manufacturing the marker 26 will be described with reference to FIGS. 4A to 4D.

[0043] First, as shown in Fig. 4A, a plurality of wires 42 that form the stripe portion 32a and ring portion 32b of the contrast imaging section 26b are prepared. The wires 42 are formed into a rod shape from a contrast-imaging wire made of a metal material or a resin material containing a contrast agent. The plurality of wires 42 that form the stripe portion 32a (hereinafter referred to as first wires 42a) are arranged at equal intervals in the width direction (direction of arrow C).

[0044] After the plurality of first wires 42a are arranged as shown in Fig. 4A, a lamination process is performed in which all of the first wires 42a are sandwiched between films 44 made of a resin material, as shown in Fig. 4B. This forms a marker manufacturing sheet 46 in which the plurality of first wires 42a are fixed in predetermined positions by the films 44. The films 44 form the supports 26a in the marker 26.

[0045] As shown in Fig. 4C, the marker-manufacturing sheet 46 is cut to a desired length in the longitudinal direction of the first wire 42a to form small sheet pieces 48. A wire 42 (hereinafter, referred to as the second wire 42b) that will become the ring portion 32b is placed at the longitudinal end of the sheet piece 48. The second wire 42b is placed so as to intersect with and straddle the multiple first wires 42a. The second wire 42b is fixed to the end of the sheet piece 48 by, for example, thermal welding.

[0046] 4D, the sheet piece 48 is bent into a ring shape, and the widthwise ends of the sheet piece 48 are fused together by heat welding or the like. This forms a cylindrical marker 26 that covers the first and second wire materials 42a, 42b. The multiple first wire materials 42a form the stripe portion 32a, the second wire material 42b forms the ring portion 32b, and the sheet piece 48 forms the support body 26a.

[0047] Next, we will explain the case where the catheter 10 is used as an antegrade catheter 18 to treat a blood vessel in the lower limb. Figure 1 shows a blood vessel 14 in the lower limb that has a main tube 14a and first and second branch tubes 14b, 14c that bifurcate downstream of the main tube 14a, with a CTO 16a (lesion 16) occurring in the first branch tube 14b. The first branch tube 14b and the second branch tube 14c are bent in directions that move away from each other downstream.

[0048] In the blood vessel 14 shown in FIG. 1, the left side of the CTO 16a in the main tube 14a and the first branch tube 14b is the central side (heart side) and the upstream side of the blood flow. The right side of the CTO 16a in the first branch tube 14b is the peripheral side (ankle side) and the downstream side of the blood flow. Hereinafter, the blood vessel 14 (first branch tube 14b) upstream (left) of the CTO 16a will be referred to as the upstream blood vessel 14d, and the blood vessel 14 (first branch tube 14b) downstream (right) of the CTO 16a will be referred to as the downstream blood vessel 14e. The upstream blood vessel 14d is an artery with a relatively large diameter. The downstream blood vessel 14e is a peripheral blood vessel with a smaller diameter than the upstream blood vessel 14d.

[0049] First, as shown in FIG. 1 , an antegrade approach is performed with an antegrade catheter 18 into a blood vessel 14 in the lower limb of a living body 12. A medical professional (not shown) percutaneously inserts the distal end 24a of the antegrade catheter 18 into the main lumen 14a of the blood vessel 14. The distal end 24a of the antegrade catheter 18 is advanced distally (in the direction of arrow A) along a guidewire (not shown) within the blood vessel 14 toward the CTO 16a. At this time, the medical professional (not shown) can visually confirm the distal end position (distal end 24b) of the antegrade catheter 18 by visualizing the marker 26 as a radiographic image on a display or the like under X-ray angiography, thereby performing the procedure. The ring portion 32b of the marker 26 allows the marker 26 to be visually recognized from any circumferential position of the distal end 24a of the antegrade catheter 18 (see FIG. 3 ).

[0050] At the branch point between the first branch pipe 14b and the second branch pipe 14c, a medical professional (not shown) rotates the antegrade catheter 18 to point the tip 24a toward the first branch pipe 14b, thereby allowing the tip 24a of the antegrade catheter 18 to be advanced appropriately along the first branch pipe 14b. At this time, because the tip 24a of the antegrade catheter 18 is bent at the bending portion 28, it is easy to advance the tip 24a toward the bent first branch pipe 14b.

[0051] As shown in Figure 5, the tip 24a (leading edge 24b) of the antegrade catheter 18 is delivered along the upstream blood vessel 14d to the upstream end of the CTO 16a. The upstream end of the CTO 16a has a protruding portion 50 that is convex toward the upstream blood vessel 14d (in the direction of arrow B). The leading edge 24b of the antegrade catheter 18 comes into contact with the protruding portion 50. A medical professional (not shown) can use the marker 26 to confirm the position of the tip 24a of the antegrade catheter 18 as a radiological image on a display or the like.

[0052] After the tip 24a of the antegrade catheter 18 is delivered to the upstream end of the CTO 16a, a retrograde approach is performed in which the tip 36a of the retrograde catheter 20 is delivered to the CTO 16a along the downstream vascular portion 14e.

[0053] The distal end 36a of the retrograde catheter 20 is percutaneously inserted into the downstream blood vessel portion 14e of the blood vessel 14 (see FIG. 1). At this time, a guidewire 38 is inserted through the second lumen 34 of the retrograde catheter 20. With the distal end 38a of the guidewire 38 protruding distally (in the direction of arrow B) from the most distal end 36b of the retrograde catheter 20, the distal end 36a of the retrograde catheter 20 is advanced centrally (in the direction of arrow B) along the guidewire 38 toward the CTO 16a. The direction of advancement of the antegrade catheter 18 (first direction, toward the periphery) is opposite to the direction of advancement of the retrograde catheter 20 (second direction, toward the central side). In other words, the distal end 36a of the retrograde catheter 20 advances toward the distal end 24a of the antegrade catheter 18.

[0054] The distal end 36a of the retrograde catheter 20 is delivered along the downstream blood vessel portion 14e to the downstream end of the CTO 16a. The downstream end of the CTO 16a has a recessed portion 52 recessed toward the upstream blood vessel portion 14d. The distal end 36b of the retrograde catheter 20 is inserted into the recessed portion 52.

[0055] As the distal end 36a of the retrograde catheter 20 is further advanced, the distal end 36a advances from the depression 52 into the interior of the CTO 16a. The distal end 36a (leading edge 36b) of the retrograde catheter 20 excavates the CTO 16a, forming a perforation 54. The perforation 54 is formed from the bottom of the depression 52 toward the protrusion 50. As the retrograde catheter 20 advances, the perforation 54 penetrates all the way to the upstream end (protrusion 50) of the CTO 16a.

[0056] As shown in FIG. 6 , the tip of the guidewire 38 penetrates the CTO 16a and protrudes distally from the protruding portion 50. A medical professional (not shown) confirms the relative positions of the marker 26 of the antegrade catheter 18 and the tip 38a of the guidewire 38 under X-ray fluoroscopy and adjusts the direction of the guidewire 38 so that the tip 38a of the guidewire 38 is parallel to the striped portion 32a of the marker 26. After the guidewire 38 and the striped portion 32a are aligned parallel, the tip of the guidewire 38 is advanced toward the center of the ring portion 32b of the marker 26. The tip 38a of the guidewire 38 is inserted into the first lumen 22 of the first catheter body 24.

[0057] In this case, even if the tip 24a of the antegrade catheter 18 has a bent portion 28 and the tip 24a is inclined relative to the base end, the guide wire 38 can be easily and reliably inserted into the first lumen 22 by advancing the guide wire 38 toward the antegrade catheter 18 along the striped portion 32a of the marker 26.

[0058] As shown in Figure 7, by bringing the distal end 24a of the antegrade catheter 18 and the distal end 38a of the retrograde catheter 20 closer to each other along the guidewire 38, the distal end 24a (leading edge 24b) of the antegrade catheter 18 advances into the CTO 16a along the perforation 54. Inside the CTO 16a, the distal end 38a of the retrograde catheter 20 is inserted into the first lumen 22 of the distal end 24a of the antegrade catheter 18. At this time, because a perforation 54 has been formed in the CTO 16a, the distal end 24a of the antegrade catheter 18 is smoothly inserted into the CTO 16a along the perforation 54. The distal end 24a of the antegrade catheter 18 pushes the perforation 54 radially outward.

[0059] After the distal end 24a of the antegrade catheter 18 is placed at a predetermined position inside the CTO 16a, the retrograde catheter 20 is removed. A balloon catheter (not shown) is inserted into the first lumen 22 of the antegrade catheter 18 and delivered to the CTO 16a. The CTO 16a is treated with the balloon catheter. Alternatively, after a guidewire (not shown) is inserted into the first lumen 22 of the antegrade catheter 18, the antegrade catheter 18 may be removed, the guidewire may be left in place, and the balloon catheter may be delivered to the CTO 16a along the guidewire (not shown).

[0060] Insertion of the distal end portion 36a of the retrograde catheter 20 into the distal end portion 24a of the antegrade catheter 18 is not limited to being performed inside the CTO 16a. The distal end portion 36a of the retrograde catheter 20 may be inserted into the distal end portion 24a of the antegrade catheter 18 in the upstream blood vessel portion 14d or the downstream blood vessel portion 14e near the CTO 16a.

[0061] The catheter 10 used as the antegrade catheter 18 is not limited to a configuration including a bent section 28. As shown in Fig. 8, the catheter 10a (antegrade catheter 18a) may also be provided with a first catheter body 25 that is linear along the axial direction. The catheter 10a is ideal for use in treating unbranched blood vessels 14 in the lower extremities, for example.

[0062] As described above, in the embodiment of the present invention, in the catheter 10 (antegrade catheter 18), the striped portion 32a of the marker 26 and the first lumen 22 are arranged parallel to each other. Therefore, when a medical professional inserts the guidewire 38 into the first lumen 22 from the distal end 24a of the first catheter body 24 under X-ray imaging, the medical professional can easily coaxially align the guidewire 38 and the first catheter body 24 while visually checking the striped portion 32a, and insert the guidewire 38 into the first lumen 22 of the first catheter body 24. This makes it possible to easily align the guidewire 38 and the first catheter body 24, thereby reducing the radiation exposure of the medical professional and the living body when performing work under X-ray imaging.

[0063] The tip portion 24a of the first catheter body 24 has a bent portion 28 at a position a predetermined distance away from the most distal end 24b of the first catheter body 24 in the proximal direction, and the stripe portion 32a extends at least to the bent portion 28. Therefore, even if the tip portion 24a of the first catheter body 24 has the bent portion 28, the guide wire 38 can be easily aligned coaxially with the first lumen 22 by the stripe portion 32a arranged parallel to the first lumen 22.

[0064] The distance between the most distal end 26c of the marker 26 and the most distal end 24b of the first catheter body 24 in the axial direction of the first catheter body 24 is 0.5 mm or less, so when the antegrade catheter 18 is advanced along the blood vessels 14 of the living body 12, the position of the tip of the antegrade catheter 18 can be confirmed with high accuracy under X-ray angiography.

[0065] The marker 26 has a ring portion 32b that is formed in a ring shape along the circumferential direction of the first catheter body 24 and that constitutes the leading end 26c of the marker 26. Therefore, by visually checking the ring portion 32b under X-ray imaging, medical personnel can more easily and accurately confirm the leading end 26c of the marker 26, and thereby accurately confirm the tip position of the antegrade catheter 18.

[0066] When inserting the tip of the retrograde catheter 20 into the tip of the antegrade catheter 18, the insertability of the tip of the retrograde catheter 20 can be improved by inserting the guide wire 38 along the striped portion 32a of the marker 26 located at the tip portion 24a.

[0067] The present invention is not limited to the above disclosure, and various configurations may be adopted without departing from the spirit of the present invention. For example, the lesion 16 does not have to be a typical CTO 16a, but may be a severe stenotic lesion through which some blood flow is observed, or may be a mild stenotic lesion to reduce the burden on the patient. [Explanation of symbols]

[0068] 10, 10a...catheter 12...biological 14...Blood vessel 16...Lesion 16a...CTO 18, 18a...antegrade catheter 20... retrograde catheter 24, 25... first catheter body 26...Marker 32a...Stripes 32b...Ring section

Claims

1. A catheter that can be inserted into a lumen of a living body and advanced along the lumen, a tubular catheter body having a lumen; a marker including a radiopaque material and disposed at the distal end of the catheter body; Equipped with A catheter, wherein the marker has a stripe portion parallel to the extension direction of the lumen.

2. The catheter of claim 1, the distal end portion of the catheter body has a bent portion at a position a predetermined distance away from the most distal end of the catheter body in a proximal direction, The catheter, wherein the striped portion extends to at least the bent portion.

3. The catheter of claim 1, A catheter, wherein the distance between the most distal end of the marker and the most distal end of the catheter body in the axial direction of the catheter body is 0.5 mm or less.

4. The catheter of claim 1, A catheter, wherein the marker has a ring portion that is formed in an annular shape along the circumferential direction of the catheter body and that constitutes the most distal end of the marker.

5. The catheter according to any one of claims 1 to 4, The catheter is an antegrade catheter that advances along the lumen to the peripheral side of the living body.

6. A method for treating a lesion in a lumen using an antegrade catheter that advances along a lumen of a living body toward a peripheral side of the living body and a retrograde catheter that advances along the lumen toward a central side of the living body, comprising: The antegrade catheter comprises: a first tubular catheter body having a first lumen; a marker including a radiopaque material and disposed at the distal end of the first catheter body; Equipped with The marker has a stripe portion parallel to an extension direction of the first lumen, the retrograde catheter includes a second tubular catheter body having a second lumen; The method of treatment comprises: advancing the antegrade catheter distally within the lumen of the living body; advancing the retrograde catheter with a guide wire inserted through the second lumen toward the central side; and inserting the tip of the guide wire into the first lumen while checking the position of the striped portion of the marker and the guide wire under radioscopy, and inserting the tip of the retrograde catheter into the tip of the antegrade catheter.

Images