Catheter, catheter manufacturing method, and contrast marker crimping method

Abstract

To provide a catheter which suppresses exposure of a contrast marker and can improve a yield, a method of manufacturing the catheter, and a method of caulking the contrast marker.SOLUTION: A support catheter 1 comprises: a distal shaft 33 as a pipe having a second constituent outer layer 38 and an inner layer 35; an annular contrast marker 40 arranged between the second constituent outer layer 38 and the inner layer 35 so that its axial direction is substantially parallel with an axial direction of the distal shaft 33; and a tip-side portion 34a of a proximal shaft 34 arranged between the second constituent outer layer 38 and the contrast marker 40. A cross section of the contrast marker 40 perpendicular to the axial direction has a protrusion part 40a projecting to a radially outer side of the contrast marker 40, the protrusion part 40a being unevenly present in a first portion 401 within a range of one third of an outer periphery of the contrast marker 40 in the cross section. The tip-side portion 34a is arranged in the vicinity of the protrusion part 40a of the contrast marker 40.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to catheters, methods for manufacturing catheters, and methods for crimping contrast markers when manufacturing catheters. [Background technology]

[0002] Catheters have been used as a type of medical instrument for examining, treating, etc., tubular tissues within the body, such as blood vessels. Known catheters include, for example, guiding catheters for guiding an intervention device into a blood vessel when treating a stenosis, support catheters used together with the guiding catheter, balloon catheters equipped with a balloon used to dilate a stenosis, aspiration catheters for removing lesions, thrombi, etc., within a blood vessel, and penetration catheters for penetrating a stenosis.

[0003] When using a catheter, it is desirable to perform medical procedures while checking the position of the catheter in the living body, and it is common to attach a radiopaque contrast marker to the catheter so that the placement position of the catheter in the living body can be checked. With this configuration, while the catheter is placed in the patient's blood vessel, radiation is irradiated to visualize the part where the radiopaque contrast marker is attached, thereby checking the position of the catheter (see, for example, Patent Document 1).

[0004] Patent Document 1 discloses a treatment catheter and a support catheter that is used together with a guiding catheter for guiding the treatment catheter and guides the distal portion of the treatment catheter to the treatment site. The support catheter includes a tubular distal shaft into which the treatment catheter can be inserted and a proximal shaft whose distal portion is connected to the distal shaft. The document also discloses that an annular contrast marker may be placed at the connection portion of the distal shaft and the proximal shaft to, for example, identify the proximal opening of the distal shaft when inserting the treatment catheter into the distal shaft. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 153321 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, one procedure for placing a ring-shaped contrast marker at a desired position on a catheter is to place a contrast marker having a diameter slightly larger than the outer diameter of the precursor at a predetermined position on a tubular precursor that is the raw material for the catheter, and then crimp the contrast marker to fix it to the precursor.

[0007] Figure 14 shows a cross section perpendicular to the axial direction of a radiopaque marker 940 that has been crimped using a conventional method. When a circular radiopaque marker 940 is crimped using a conventional method, the radiopaque marker 940 is deformed into a polygonal shape (a regular hexagon in Figure 14). When a circle C is inscribed in a side 940d of the polygonal shape, multiple protrusions 940a are formed that protrude radially outward from the circle C, and these are arranged approximately evenly in the circumferential direction (six protrusions are arranged approximately evenly in the circumferential direction in Figure 14).

[0008] After the contrast marker 940 is crimped, an outer layer is provided to cover the precursor and the contrast marker 940, but the convex portion 940a of the contrast marker 940 is closer to the outer surface of the outer layer than the side portion 940d, and the convex portion 940a may be exposed on the outer surface of the outer layer, as shown in Figure 15, for example.

[0009] If the protrusion 940a of the contrast marker 940 is exposed, it may damage devices or internal body tissues that are located outside the catheter. In particular, with the support catheter of Patent Document 1, there is a possibility that a guide wire, a balloon, or the like may be passed outside the support catheter, and the exposed protrusion 940a is likely to damage these devices.

[0010] To avoid the above problems, measures such as thickening the outer layer or covering the portion where the radiopaque marker 940 is located with a cover tube are conceivable, but these are not preferable because they increase the outer diameter of the distal shaft. Therefore, at present, catheters in which the exposed protrusion 940a of the radiopaque marker 940 is visually confirmed are rejected as visually defective, resulting in a problem of reduced catheter yield.

[0011] Therefore, the present disclosure provides a catheter, a method for manufacturing a catheter, and a method for crimping a contrast marker, which can suppress exposure of the contrast marker and improve yield. [Means for solving the problem]

[0012] In order to solve the above-mentioned problems, the catheter disclosed herein comprises a tubular material having an outer layer and an inner layer, a ring-shaped contrast marker arranged between the outer layer and the inner layer so that its axial direction is approximately parallel to the axial direction of the tubular material, and a member arranged between the outer layer and the contrast marker, wherein a cross section of the contrast marker perpendicular to the axial direction has a convex portion that protrudes radially outward from the contrast marker, and the convex portion is unevenly distributed in a first portion within a range of 1 / 3 of the outer circumference of the contrast marker in the cross section, and the member is arranged in the vicinity of the convex portion of the contrast marker.

[0013] As described above, in conventional techniques in which multiple protrusions are formed on a radiopaque marker and arranged approximately evenly around the circumference, the protrusions are often exposed to the outer surface, resulting in a high rate of product defects. In this configuration, the protrusions that could cause exposure of the radiopaque marker are unevenly distributed in a first portion covering one-third of the circumference of the radiopaque marker, and a component is arranged near the protrusions. The outer layer is formed by covering the inner layer with an outer layer forming tube made, for example, of a thermoplastic polyamide elastomer and a heat-shrinkable tube covering the outer layer forming tube, and then removing the heat-shrinkable tube after heat welding the outer layer forming tube. If a component is arranged outside the inner layer, the resin material of the outer layer forming tube will flow and be biased toward the component during heat welding, resulting in a bias in the thickness of the outer layer. In other words, the component side of the outer layer will be thicker than the side without the component. In this configuration, the protrusions are unevenly distributed in the first portion, and the member is disposed near the protrusions, so that the protrusions are covered by the thicker portion of the outer layer, thereby preventing the contrast marker from being exposed and improving the yield of the catheter.

[0014] In this specification, "the convex portions are unevenly distributed in a first portion covering one-third of the circumference of the radiopaque marker" means that, when the entire circumference of the radiopaque marker is taken as 1, one or more convex portions are unevenly distributed in a first portion covering one-third of the circumference, and no convex portions are present in a second portion covering at least the remaining two-thirds of the circumference. The convex portions may be located in the first portion, and may be formed over the entire first portion or only in a part of the first portion.

[0015] In addition, in this specification, "exposure (to the outer surface)" of the contrast marker or protrusions means that the protrusions break through the outer layer and protrude to the outside of the outer layer, or that the protrusions come close to the outer surface of the outer layer, so that the protrusions of the contrast marker can be clearly confirmed when a visual inspection of the catheter is performed.

[0016] This configuration can be applied to any catheter that includes a tubular material, a contrast marker, and a component, and specifically, for example, it can be applied to a support catheter that is used together with a guiding catheter to guide a therapeutic device into a blood vessel when treating a stenosis, an aspiration catheter that removes lesions, thrombi, etc. from within a blood vessel, and a scoring balloon catheter that has an element-equipped balloon.

[0017] The cross section of the contrast marker preferably has two or less convex portions.

[0018] In this configuration, the number of protrusions that could potentially expose the radiopaque marker is two or less, so the protrusions can be easily covered by the thicker parts of the outer layer, further reducing the exposure of the radiopaque marker. This reduces the exposure of the radiopaque marker and improves the yield of catheters.

[0019] The cross section of the contrast marker preferably has one of the convex portions.

[0020] With this configuration, since there is only one protrusion that could potentially expose the radiopaque marker, the protrusion can be easily covered by the thicker part of the outer layer, further suppressing exposure of the radiopaque marker. In addition, since there is only one protrusion, positioning of the components is easy when manufacturing the catheter.

[0021] It is preferable that the cross section of the contrast marker has two adjacent convex portions and a flat portion formed between the vertices of the two convex portions in the first part, and that the member is arranged on the flat portion.

[0022] According to this configuration, the member is placed on the flat portion of the radiopaque marker, so that the distal end portion can be stably held between the outer layer of the tubing and the radiopaque marker. Note that the flat portion may be completely flat, or may have a shape that is not limited to being completely flat, such as a shape having a gentle curve in part of the flat portion.

[0023] It is preferable that the height of the convex portion of the contrast marker is smaller than the thickness of the member.

[0024] According to this configuration, the height of the member protruding radially outward from the tubular material is greater than the height of the protrusion of the radiopaque marker, and therefore, when the member and the radiopaque marker are covered with the outer layer, exposure of the radiopaque marker can be more effectively suppressed.

[0025] It is preferable that the member is a wire connected at its distal end portion to the proximal end portion of the tubular member, and the contrast marker is disposed at the connection portion between the tubular member and the wire.

[0026] According to this configuration, since the radiopaque marker is disposed at the connection portion between the tubular material and the wire material, it is possible to recognize the position of the connection portion when using the catheter.

[0027] The catheter is a support catheter that is used together with a treatment catheter and a guiding catheter for guiding the treatment catheter, and guides the distal portion of the treatment catheter to the treatment site, and it is preferable that the support catheter comprises a distal shaft as the tubular material into which the treatment catheter can be inserted, and a proximal shaft as the wire material.

[0028] This configuration can prevent the contrast marker from being exposed in the support catheter.

[0029] It is preferable that the cross section of the contrast marker further has a partial annular portion including a second portion that is the remaining two-thirds of the circumference other than the first portion.

[0030] According to this configuration, at least the second portion other than the first portion where the convex portion is formed is a smooth partial annular portion without any convex portion that would cause exposure of the contrast marker, thereby more effectively suppressing exposure of the contrast marker.

[0031] The method for manufacturing a catheter disclosed herein is a method for manufacturing the above-mentioned catheter, and includes the steps of: placing the contrast marker before crimping on the outside of the inner layer; placing a coating material on the outside of the contrast marker so as to cover the area other than the area where the convex portion is to be formed; applying an external force from the outside of the coating material to crimp the contrast marker and form the convex portion; removing the coating material and placing the member near the convex portion of the contrast marker; and covering the contrast marker and the member with the outer layer.

[0032] The method for crimping a radiopaque marker disclosed herein includes a tubular member having an outer layer and an inner layer, an annular radiopaque marker disposed between the outer layer and the inner layer so that its axial direction is substantially parallel to the axial direction of the tubular member, and a member disposed between the outer layer and the radiopaque marker, wherein a cross section of the radiopaque marker perpendicular to the axial direction has a convex portion that protrudes radially outward from the radiopaque marker, and the convex portion is unevenly distributed in a first portion that is within a range of one-third of the outer circumference of the radiopaque marker in the cross section, and the member is disposed in the vicinity of the convex portion of the radiopaque marker. The method for crimping the contrast marker when manufacturing a catheter includes the steps of: placing the contrast marker before crimping on the outside of the inner layer; placing a covering material on the outside of the contrast marker so as to cover the area other than the area where the convex portion is to be formed; applying an external force from the outside of the covering material to crimp the contrast marker and form the convex portion; removing the covering material and placing the member near the convex portion of the contrast marker; and covering the contrast marker and the member with the outer layer.

[0033] According to this configuration, the coating material is positioned to cover the portions of the radiopaque marker other than the portions where the protrusions are formed, so the crimping machine does not directly contact the portions where the coating material is positioned. As a result, in the portions of the radiopaque marker where the coating material is positioned, the outer diameter of the radiopaque marker is reduced to approximately the outer diameter of the inner layer by the pressure of the crimping machine, but no protrusions are formed. Furthermore, since the number of protrusions that could cause exposure of the radiopaque marker can be reduced, exposure of the radiopaque marker can be suppressed and the yield of catheters can be improved. [Effects of the Invention]

[0034] As described above, according to the present disclosure, exposure of the contrast marker can be suppressed, and the yield of catheters can be improved. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 1 is a diagram showing a support catheter according to an embodiment in use. [Figure 2] Figure 1. Overall view of the support catheter. [Figure 3] Cross-sectional view taken along line AA in Figure 2. [Figure 4] 10A and 10B are diagrams for explaining the relationship between the height of the convex portion of the contrast marker and the thickness of the distal end portion of the proximal shaft. [Figure 5] FIG. 4 is a diagram equivalent to FIG. 4 in which the width of the convex portion of the contrast marker is narrowed. [Figure 6] Photograph of the appearance of the support catheter of the embodiment. [Figure 7] FIG. 1 is a flow chart illustrating a method for manufacturing a support catheter according to one embodiment. [Figure 8] FIG. 10 is a diagram showing the precursor after the contrast marker crimping process. [Figure 9] 10A and 10B are diagrams for explaining a method of caulking a contrast marker. [Figure 10] FIG. 10 shows the precursor after the proximal shaft connection step. [Figure 11] FIG. 5 is a view equivalent to FIG. 4 showing a contrast marker and a distal end portion of a proximal shaft according to another embodiment. [Figure 12] 10A and 10B are diagrams for explaining a method for caulking a contrast marker according to another embodiment. [Figure 13] FIG. 10 is a cross-sectional view of a suction catheter according to another embodiment. [Figure 14] 10 is a cross-sectional view of a contrast marker crimped by a conventional crimping method. [Figure 15] Photograph of the appearance of a catheter equipped with a contrast marker crimped using a conventional crimping method. DETAILED DESCRIPTION OF THE INVENTION

[0036] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present disclosure, its applications, or its uses.

[0037] (First embodiment) <Support catheter> The following describes a support catheter as an example of a catheter according to the present disclosure. The support catheter is used together with a treatment catheter and a guiding catheter for guiding the treatment catheter, and is used to guide the distal portion of the treatment catheter to the treatment site.

[0038] 1, percutaneous coronary intervention (PCI) is known as one of the procedures for dilating a stenosis 3 (treatment site) formed in, for example, a coronary artery 2. PCI mainly uses a guiding catheter 4, a balloon catheter 5 (treatment catheter), a support catheter 1, and a guidewire 25.

[0039] The guiding catheter 4 is a catheter for guiding the balloon catheter 5 and the support catheter 1 inside a blood vessel. The guiding catheter 4 is inserted into, for example, the radial artery 8 using a sheath 7, and is advanced until its distal opening 4a passes through the aortic arch 9 and reaches the entrance 2a of the coronary artery 2. The main body 11 of the guiding catheter 4 is a long tube made of a bendable, flexible material, which can be advanced through a curved blood vessel and into which the balloon catheter 5 and the support catheter 1 can be inserted. The Y-shaped connector 12 of the guiding catheter 4 is provided at the proximal end of the main body 11 and has a main body portion 12a and a side arm 12b. The balloon catheter 5 and the support catheter 1 are inserted into the main body 11 via the proximal opening 4b and the main body portion 12a. Medicinal solutions, contrast agents, etc. are injected through the side arm 12b.

[0040] The balloon catheter 5 is a treatment catheter that is inserted into a stenotic portion 3 in a coronary artery to expand the stenotic portion 3. The balloon catheter 5 is, for example, a rapid exchange type (RX type) catheter, and as shown in Fig. 1, has a treatment catheter main body 21 and a connector 22. The treatment catheter main body 21 is a long tube, and has a balloon 23 with a stent 24 mounted on its distal end portion.

[0041] When the distal opening 4a of the guiding catheter 4 reaches the entrance 2a of the coronary artery 2, the guide wire 25, the support catheter 1, and the balloon catheter 5 are inserted in this order from the proximal opening 4b of the guiding catheter 4, and the stenosis 3 is treated.

[0042] The guiding catheter 4, the balloon catheter 5 and the guidewire 25 may be any known catheter.

[0043] The support catheter 1 of this embodiment will be described in detail below.

[0044] The support catheter 1 is advanced from the entrance 2a of the coronary artery 2 to a position closer to the stenosis 3, and serves to guide the balloon 23 of the balloon catheter 5 to the stenosis 3. The support catheter 1 also serves to support the balloon 23 when inserting the balloon 23 into the stenosis 3. The support catheter 1 is inserted from the proximal opening 4b of the guiding catheter 4, and has a length that allows it to protrude from the distal opening 4a of the guiding catheter 4.

[0045] As shown in FIG. 2, the support catheter 1 includes a protective member 32, a distal shaft 33 (tubular material), a proximal shaft 34 (wire material), and a contrast marker 40.

[0046] [Distal shaft] The distal shaft 33 constitutes the distal end portion 1a of the support catheter 1 and is a tubular material configured to allow the insertion of a balloon catheter 5. The distal shaft 33 has a laminated structure including an inner layer 35, an outer layer including a first constituent outer layer 37, a second constituent outer layer 38, and a distal tip 39, and a reinforcing layer 36 disposed between the inner layer 35 and the first constituent outer layer 37 and second constituent outer layer 38.

[0047] The inner layer 35 of the distal shaft 33 is formed of, for example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), or the like.

[0048] The first constituent outer layer 37 of the distal shaft 33 is formed of, for example, pelprene (a polyester-based elastomer resin), nylon (a polyamide-based elastomer resin), etc. The hardness of the first constituent outer layer 37 is lower than the hardness of the second constituent outer layer 38 in order to improve the insertability into thin, tortuous blood vessels.

[0049] The second outer layer 38 of the distal shaft 33 is disposed in contact with the first outer layer 37 along the axial direction of the distal shaft 33. The second outer layer 38 covers the proximal portion of the distal shaft 33 after the contrast marker 40 and the distal portion 34a of the proximal shaft 34 are disposed at the proximal portion of the distal shaft 33 by a method described below. The second outer layer 38 is formed of, for example, polybutylene terephthalate, pelprene (a polyester-based elastomer resin), nylon (a polyamide-based elastomer resin), or the like. From the viewpoints of ensuring the pushability of the support catheter 1, preventing breakage of the connection portion between the distal shaft 33 and the proximal shaft 34, and suppressing stretching of the outer layer resin during operation of the proximal shaft 34, the hardness of the second outer layer 38 is made higher than the hardness of the first outer layer 37.

[0050] The inner layer 35, the first outer layer 37, and the second outer layer 38 may be made of the same material and are not limited to the materials described above. To protect the surface of the distal shaft 33, the outer peripheral surfaces of the first outer layer 37, the second outer layer 38, and the distal tip 39 may be coated with polyurethane, polyvinylpyrrolidone (PVP), methyl vinyl ether (MVE), or the like. While the number of outer layers other than the distal tip 39 is two, the first outer layer 37 and the second outer layer 38, this is not limitative and the number may be three or more. For example, if the difference in hardness between the first outer layer 37 and the second outer layer 38 is large, an outer layer resin with an intermediate hardness may be sandwiched between the first outer layer 37 and the second outer layer 38, so that the distal shaft 33 does not kink due to a sudden change in hardness. Thus, three types of outer layers may be arranged longitudinally.

[0051] The distal tip 39 is provided at the distal end of the distal shaft 33. This distal tip 39 is a tube made of polyamide elastomer containing, for example, bismuth oxide, a contrast agent. The distal tip 39 is radiopaque so that a shadow appears under fluoroscopy. The hardness of the distal tip 39 is lower than that of the first constituent outer layer 37 so as not to damage the tissue when it comes into contact with the inner wall of a blood vessel.

[0052] The reinforcing layer 36 of the distal shaft 33 is intended to prevent kinking of the distal shaft 33 and ensure its insertability into blood vessels. It is made of a cylindrical mesh of multiple metal wires (element wires) 36a, such as stainless steel, tungsten, or nickel titanium. The reinforcing layer 36 is provided over most of the distal shaft 33, except for the distal end where the distal tip 39 of the distal shaft 33 is located and the proximal end where the radiopaque marker 40 is located. By not providing the reinforcing layer 36 at the distal and proximal ends, the metal wires (element wires) 36a constituting the reinforcing layer 36 can be prevented from protruding from the distal shaft 33 and causing damage to the living body. This also ensures flexibility at the distal end of the support catheter 1. Furthermore, the thinner wall at the proximal end facilitates insertion of the balloon catheter 5 into the distal shaft 33, and prevents an increase in the outer diameter even when the distal end portion 34a of the proximal shaft 34 is located.

[0053] The proximal end of the distal shaft 33 may have an obliquely cut shape, an arc shape, or a crescent shape, which makes it easier to insert the balloon catheter 5 into the distal shaft 33.

[0054] [Proximal shaft] The proximal shaft 34 constitutes the base end portion 1b of the support catheter 1 and is a long wire made of, for example, stainless steel, nickel titanium, etc. The surface of the proximal shaft 34 may be coated with, for example, a fluororesin such as PTFE, PFA, or ETFE.

[0055] A protective member 32 is provided at the base end of the proximal shaft 34. The protective member 32 is held by the practitioner to operate the support catheter 1, and is a plate-shaped member made of, for example, polyamide elastomer.

[0056] As will be described later, the distal portion 34a of the proximal shaft 34 is connected to the proximal portion of the distal shaft 33. The distal portion 34a of the proximal shaft 34 is formed to be wider than the remaining portion (see FIG. 10). The distal portion 34a is formed into a flat plate shape by pressing or machining the distal end of the proximal shaft 34, which is a wire material. The shape of the distal portion 34a is not limited to being wide.

[0057] From the viewpoint of strengthening the connection between the proximal shaft 34 and the distal shaft 33, it is desirable that the width (length in the direction perpendicular to the axial direction) of the distal portion 34a of the proximal shaft 34 be, for example, 8% to 15% of the circumferential length of the distal shaft 33. It is also desirable that the thickness of the distal portion 34a be equal to or smaller than the diameter of the wire material of the proximal shaft 34.

[0058] [Contrast marker] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2, showing the axis L of the annular contrast marker 40. 40 1 shows a cross section perpendicular to the direction in which the contrast marker 40 extends (hereinafter also referred to as the "axial direction of the contrast marker 40").

[0059] As shown in FIGS. 2 and 3, the axial direction of the contrast marker 40 is aligned with the axis L of the distal shaft 33. 33 The marker 40 is disposed at the connection portion 1c between the distal shaft 33 and the proximal shaft 34 so as to be approximately parallel to the direction in which the marker 40 extends (hereinafter also referred to as the "axial direction of the distal shaft 33"). In this specification, the term "approximately parallel" includes the term "completely parallel" and does not mean that the marker 40 is completely parallel to the axis L of the marker 40. 40 and the axis L of the distal shaft 33 33 This means that the angle between the two is 5° or less.

[0060] The radiopaque marker 40 is made of a metal such as stainless steel, platinum, or tantalum, and is radiopaque. By providing the radiopaque marker 40, the position of the distal end portion 34a of the proximal shaft 34 can be visualized under radioscopy. This serves as a marker for the proximal opening of the distal shaft 33 when inserting a treatment catheter into the distal shaft 33.

[0061] As shown in Figure 3, the contrast marker 40 and the distal portion 34a of the proximal shaft 34 are positioned inside the second constituent outer layer 38 of the distal shaft 33 in order to protect them and to strengthen the connection between the distal shaft 33 and the proximal shaft 34.

[0062] In a cross section perpendicular to its axial direction, the radiopaque marker 40 has one convex portion 40a that protrudes radially outward from the radiopaque marker 40, and a partial annular portion 40b. In this embodiment, the partial annular portion 40b constitutes the portion other than the convex portion 40a.

[0063] As described above, in the conventional radiopaque marker 40, the plurality of protrusions are arranged approximately uniformly in the circumferential direction, so that the protrusions are exposed to the outer surface of the outer layer, resulting in a high proportion of products having poor appearance.

[0064] The contrast marker 40 of this embodiment has one protruding portion 40a, and the first portion 401 (axis L) is located in the range of one-third of the outer periphery of the contrast marker 40. 40 The contrast marker 40 is unevenly distributed in a second portion 402 (a portion in which the angle θ around the axis L is in the range of more than 0° and not more than 120°) in the remaining two-thirds of the outer periphery of the contrast marker 40. 40 The part where the circumferential angle θ is in the range of more than 120° and 360° or less) constitutes a part or the whole of the partial annular portion 40b and does not have the protrusion 40a.

[0065] The distal end portion 34a of the proximal shaft 34 is located outside the radiopaque marker 40 and in the vicinity of the convex portion 40a of the radiopaque marker 40, preferably adjacent to the convex portion 40a.

[0066] The distal end portion 34a of the proximal shaft 34 has a certain thickness. Therefore, by arranging the distal end portion 34a near the protruding portion 40a of the radiopaque marker 40, particularly adjacent to the protruding portion 40a, when the radiopaque marker 40 and the distal end portion 34a are covered with the second outer layer 38, the protruding portion 40a is covered by the thick portion of the second outer layer 38. As a result, exposure of the radiopaque marker 40 can be effectively suppressed.

[0067] Specifically, the second outer layer 38 can be formed by covering the inner layer 35 with a second outer layer forming tube made of, for example, a thermoplastic polyamide elastomer and a heat-shrinkable tube covering the outer layer forming tube, heat-welding the second outer layer forming tube, and then removing the heat-shrinkable tube. If the distal end portion 34a of the proximal shaft 34 is disposed outside the inner layer 35, during heat-welding of the second outer layer forming tube, the resin material of the second outer layer forming tube flows and becomes biased toward the distal end portion 34a, resulting in a bias in the thickness of the second outer layer 38. That is, as shown in FIG. 3, in the cross section of the connection portion 1c, the side of the second outer layer 38 where the distal end portion 34a is disposed is thicker than the side where the distal end portion 34a is not present. In this embodiment, the protrusions 40a are unevenly distributed in the first portion 401, and the distal end portion 34a of the proximal shaft 34 is disposed near the protrusions 40a, so that the protrusions 40a are covered by the thick portions of the second constituent outer layer 38. This makes it possible to suppress exposure of the radiopaque marker 40, and improve the yield of the support catheter 1.

[0068] As shown in FIG. 4, in this specification, the “nearby” of the convex portion 40a is defined as the distance between the apex of the convex portion 40a and the center of the distal end portion 34a of the contrast marker 40 in the circumferential direction of the contrast marker 40 along the axis L 40 This means that the angle β around the periphery is within 90°.

[0069] In addition, in this embodiment, the partial annular portion 40b other than the convex portion 40a is a smooth partial annular portion without any convex portion, which effectively suppresses exposure of the contrast marker 40. In this specification, the "partial annular portion" of the partial annular portion 40b means a part of a ring made up of a perfect circle and an ellipse.

[0070] As shown in FIG. 4, it is assumed that the protrusion 40a of the contrast marker 40 protrudes radially outward from the ring 41 defined by the partial ring portion 40b. The height H of the protrusion 40a is 40a Consider the height H of the protrusion 40a. 40a The height H of the protrusion 40a can be set to, for example, 5% to 15% of the radius of the annulus 41. 40a If the height H of the protrusion 40a is less than the lower limit, the radiopaque marker 40 will not be sufficiently caulked, which may cause the radiopaque marker 40 to move or fall off. 40a If the upper limit is exceeded, the possibility of the protrusion 40a being exposed increases.

[0071] In addition, the height H of the protrusion 40a 40a is the thickness H of the distal end portion 34a of the proximal shaft 34. 34a Specifically, the height H of the protrusion 40a is preferably smaller than 40a is the thickness H of the tip side portion 34a 34a is preferably less than 100%, more preferably 95% or less, and more preferably 90% or less. According to this configuration, the distal portion 34a of the proximal shaft 34 protrudes radially outward from the distal shaft 33 to a greater extent than the protruding portion 40a of the radiopaque marker 40. Therefore, when the distal portion 34a and the radiopaque marker 40 are covered with the second component outer layer 38, exposure of the radiopaque marker 40 can be effectively suppressed.

[0072] Although not intended to be limiting, the height H of the protrusion 40a 40a is the thickness H of the tip side portion 34a 34a This ensures that the inner diameter of the radiopaque marker 40 before crimping is sufficient relative to the outer dimensions of the inner layer 35, making it easy to arrange the radiopaque marker 40 in the inner layer 35.

[0073] 4 and 5, the width of the convex portion 40a may be wide or narrow. Specifically, the width of the contrast marker 40 is determined by the distance from the center of the ring 41, i.e., the axis L 40 The width is such that the angle α around the circumference is preferably 5° to 80°, more preferably 8° to 70°. If the angle α is below the lower limit, the width of the protrusion 40a is too narrow, which may result in insufficient crimping of the radiopaque marker 40. If the angle α exceeds the upper limit, the width of the protrusion 40a is too wide, which may result in reduced stability in the fixation of the radiopaque marker 40 to the inner layer 35 by the partial annular portion 40b.

[0074] FIG. 6 is a digital microscope photograph showing the appearance of an example of the support catheter 1 according to this embodiment.

[0075] As described above, with conventional catheters, exposure of the convex portion 40a of the radiopaque marker 40 was often observed, as shown in Figure 14. On the other hand, with the support catheter 1 of the example, the position of the convex portion 40a of the radiopaque marker 40 was slightly observable, but exposure of the convex portion 40a was not observed, as shown in Figure 6. In this way, with the support catheter 1 of this embodiment, exposure of the radiopaque marker 40 can be effectively suppressed.

[0076] <Support catheter manufacturing method> Next, a method for manufacturing the support catheter according to this embodiment will be described with reference to FIGS.

[0077] As shown in Figure 7, the manufacturing method of the support catheter of this embodiment includes an inner layer forming step S1, a reinforcing layer forming step S2, a contrast marker placement step S3, a contrast marker crimping step S4, a proximal shaft connecting step S5, and an outer layer forming step S6.

[0078] [Inner layer formation process] 8, in the inner layer forming step S1, for example, a resin material such as PTFE is applied to the outer surface of a silver-plated copper wire 50 to form the inner layer 35. In this way, a precursor of the distal shaft 33 is obtained.

[0079] [Reinforcement layer formation process] Next, in the reinforcing layer formation step S2, the reinforcing layer 36 is formed on the outer surface of the inner layer 35. Specifically, for example, half of the several tens of metal wires 36a are spirally wound in one direction around the outer peripheral surface of the inner layer 35, and the remaining half are spirally wound in the other direction around the outer peripheral surface of the inner layer 35. At this time, the length of the reinforcing layer 36 is adjusted so that the base end portion and the tip end portion of the inner layer 35 slightly protrude (expose) from the base end portion and the tip end portion of the reinforcing layer 36, respectively. Note that the number of wound metal wires 36a and the ratio of the number wound in one direction to the number wound in the other direction are not limited to those described above. The method of winding the metal wires 36a is not limited to a spiral winding, and various conventionally known methods can be used.

[0080] [Contrast marker placement process] Next, in the radiopaque marker placement step S3, a circular radiopaque marker 40 before crimping is placed on the outer surface of the inner layer 35 in a portion of the proximal portion of the precursor where the reinforcing layer 36 is not provided. The radiopaque marker 40 before crimping has an inner diameter slightly larger than the outer diameter of the inner layer 35.

[0081] [Contrast marker crimping process] 9, in the radiopaque marker crimping step S4, a covering material 211 is placed on the outside of the radiopaque marker 40 so as to cover the area other than the area where the protrusion 40a is formed, i.e., the area where the partial annular portion 40b is formed. The covering material 211 is made of a flexible material. Specific examples of the covering material 211 that can be used include heat-shrinkable tubing or other tubes made of polyolefin, polypropylene, acetate, or cellulose, with a portion cut away in the axial direction.

[0082] Next, an external force is applied to the precursor from the outside of the covering material 211 using a crimping machine 201. In this way, the contrast marker 40 is crimped to form the protrusion 40a.

[0083] According to this configuration, the crimping machine 201 does not come into direct contact with the portion of the radiopaque marker 40 where the covering material 211 is arranged. As a result, in the portion of the radiopaque marker 40 where the covering material 211 is arranged, although the outer diameter of the radiopaque marker 40 is reduced to approximately the outer diameter of the inner layer 35 by the pressure of the crimping machine, no protrusions 40a are formed, and instead a partial annular portion 40b is formed. This makes it possible to reduce the number of protrusions 40a that could cause exposure of the radiopaque marker 40.

[0084] In this embodiment, the radiopaque marker 40 and the reinforcing layer 36 are not connected, but may be connected. Specifically, for example, the radiopaque marker 40 may be welded to the metal wire 36a of the reinforcing layer 36 after crimping by the crimping machine 201 is completed. This allows the fixation of the radiopaque marker 40 to be strengthened.

[0085] [Proximal shaft connection process] In the proximal shaft connecting step S5, the covering material 211 is removed, and the distal portion 34a of the proximal shaft 34 is placed near the protrusion 40a of the radiopaque marker 40, as shown in Fig. 10. At this time, the distal portion 34a is placed so that the width direction of the distal portion 34a coincides with the circumferential direction of the distal shaft 33.

[0086] The distal portion 34a is covered with the second constituent outer layer 38 in the next outer layer forming step S6, and is thereby sandwiched between the inner layer 35 and the second constituent outer layer 38. This fixes the distal portion 34a. To further strengthen the fixation, it is desirable to join the distal portion 34a to the distal shaft 33 by welding, adhesive, or the like. Specifically, as shown in FIG. 10, the distal portion 34a may be fixed by welding the distal portion 34a to the metal wire 36a of the reinforcing layer 36 at welding points w1. While five welding points w1 are shown in FIG. 10, the number of welding points w1 is not limited to five and may be one to four, or six or more.

[0087] When the tip portion 34a is welded to the reinforcing layer 36, the tip portion 34a may be welded to an end of the base portion of the reinforcing layer 36, or may be welded to one or more metal wires 36a. In particular, it is desirable that the tip portion 34a be disposed on an intersection of two metal wires 36a wound unidirectionally and multidirectionally around the reinforcing layer 36, as shown in Fig. 10, and welded to the location of the intersection.

[0088] Further, although the distal end portion 34a is not welded or adhered to the radiopaque marker 40, it may be welded or adhered to the radiopaque marker 40 as well.

[0089] [Outer layer formation process] Then, in the outer layer forming step S6, a first constituent outer layer 37, a second constituent outer layer 38, and a distal tip 39 are formed as shown by the two-dot chain lines in FIG.

[0090] Specifically, for example, the outer surface of the precursor is covered with a heat-shrinkable tube covering the first outer layer, the second outer layer, and the tip-forming tube, which are materials for the first outer layer 37, the second outer layer 38, and the tip 39. The first outer layer, the second outer layer, and the tip-forming tube are then heat-welded to the inner layer 35, and the heat-shrinkable tube is then removed.

[0091] At this time, the lengths of the first constituent outer layer forming tube, the second constituent outer layer forming tube and the distal tip forming tube are adjusted so that the second constituent outer layer 38 covers the base end portion of the distal shaft 33 where the contrast marker 40 and the distal portion 34a of the proximal shaft 34 are provided, and the distal tip 39 covers the distal portion of the distal shaft 33.

[0092] By the above method, with the reinforcing layer 36, the contrast marker 40 and the distal portion 34a of the proximal shaft 34 positioned in the lumen of the first constituent outer layer 37 and the second constituent outer layer 38, the inner surfaces of the first constituent outer layer 37, the second constituent outer layer 38 and the distal tip 39 are welded to the outer surface of the inner layer 35, and the interface between the distal tip 39 and the first constituent outer layer 37 and the interface between the first constituent outer layer 37 and the second constituent outer layer 38 are welded.

[0093] Finally, the copper wire 50 is stretched and drawn out to obtain the support catheter 1.

[0094] In this embodiment, the distal portion 34a of the proximal shaft 34 and the distal shaft 33 overlap in the radial direction. In this case, the distal portion 34a of the proximal shaft 34 preferably overlaps the distal shaft 33 by a distance (overlap distance) of 5 to 25% of the total length of the distal shaft 33. If the overlap distance is shorter than the above range, the connection strength of the distal portion 34a to the distal shaft 33 is not expected to be sufficiently improved. If the overlap distance is longer than the above range, the overlapping portion becomes stiff, which may result in reduced passability. Furthermore, if the overlap distance is longer than the above range, the overlapping portion with a substantially elliptical radial cross section increases in the axial direction, thereby increasing the lumen occupancy rate of the distal shaft 33 within the guiding catheter 4. Therefore, there is a risk of increased resistance to passage of the distal shaft 33 when performing a procedure using a thinner guiding catheter 4. Furthermore, there is a risk of increased resistance to insertion of the guidewires when performing a procedure using two guidewires. Therefore, it is desirable that the overlap distance be within the above range.

[0095] (Second embodiment) A second embodiment according to the present disclosure will be described below. In the description of this embodiment, the same parts as those in the first embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted.

[0096] In this embodiment, the contrast marker 40 has two protrusions 40a arranged on the first portion 401. The two protrusions 40a may be spaced apart from each other or adjacent to each other, but are preferably adjacent to each other.

[0097] FIG. 11 shows an example in which the contrast marker 40 has two adjacent protrusions 40a in a cross section perpendicular to the axial direction of the contrast marker 40.

[0098] 11, a flat portion 42 is formed between the vertices of the two convex portions 40a in the first portion 401. The distal end portion 34a of the proximal shaft 34 is disposed on the flat portion 42. By disposing the distal end portion 34a on the flat portion 42, the distal end portion 34a can be stably held between the second component outer layer 38 and the radiopaque marker 40.

[0099] The flat portion 42 may or may not be formed. Even if the flat portion 42 is not formed, it is preferable that the tip side portion 34a is disposed between the two protrusions 40a of the first portion 401.

[0100] The two convex portions 40a and the flat portion 42 shown in Figure 11 can be formed in the contrast marker crimping process S4 by adjusting the positioning of the corners in the crimping machine 201 and the circumferential length of the covering material 211, for example, as shown in Figure 12.

[0101] (Third embodiment) A third embodiment according to the present disclosure will be described below. In the description of this embodiment, the same parts as those in the first and second embodiments will be denoted by the same reference numerals, and detailed description thereof will be omitted.

[0102] 13 shows a cross section perpendicular to the axial direction of the contrast marker 40 when a suction catheter is used as the catheter according to the present disclosure. The suction catheter 300 has, inside an outer layer 321, a suction lumen 301 (tube material) and a guidewire lumen 302 (member) provided in parallel with the suction lumen 301.

[0103] The radiopaque marker 40 is provided, for example, on the outside of the suction lumen 301. In this embodiment, similar to the first embodiment, the radiopaque marker 40 has one convex portion 40a, and the guidewire lumen 302 is arranged near the convex portion 40a. By arranging the guidewire lumen 302 near the convex portion 40a, exposure of the radiopaque marker 40 can be effectively suppressed. [Industrial Applicability]

[0104] The present disclosure is extremely useful because it can suppress exposure of contrast markers and improve catheter yields. [Explanation of symbols]

[0105] 1. Support catheter (catheter) 1c Connection (between distal and proximal shafts) 3 Stenosis area (treatment area) 4 Guiding catheter 5. Balloon catheter (therapeutic catheter) 33 Distal shaft (tube material) 34 Proximal shaft (wire) 34a Tip side part 35 inner layer 37 First component outer layer (outer layer) 38 Second component outer layer (outer layer) 40 Contrast marker 40a convex part 40b Partial annular section 42 Flat area 211 Covering material 300 Suction catheter (catheter) 321 Outer layer 401 Part 1 402 Part 2 H 34a Thickness (of the distal portion of the proximal shaft) H 40a Height (of the convex part) L 33 Axis (of the distal shaft) L 40 Axis (of contrast marker) S1 Inner layer forming process S2 Reinforcement layer formation process S3 Contrast marker placement process S4 Contrast marker crimping process S5 Proximal Shaft Connection Process S6 Outer layer formation process

Claims

1. a pipe member having an outer layer and an inner layer; an annular contrast marker disposed between the outer layer and the inner layer such that its axial direction is substantially parallel to the axial direction of the tubular material; a member disposed between the outer layer and the contrast marker, a cross section of the radiopaque marker perpendicular to the axial direction has a convex portion that protrudes radially outward of the radiopaque marker; the convex portion is unevenly distributed in a first portion within a range of one-third of the outer periphery of the contrast marker in the cross section, the member is disposed in the vicinity of the convex portion of the contrast marker, The vicinity of the convex portion means that in the cross section, the angle around the axis between the apex of the convex portion and the center of the member in the circumferential direction of the contrast marker is within 90°.

2. The catheter according to claim 1 , wherein the cross section of the contrast marker has two or less of the protrusions.

3. The catheter according to claim 1 or 2, wherein the cross section of the contrast marker has one of the protrusions.

4. the cross section of the contrast marker has two adjacent convex portions and a flat portion formed between vertices of the two convex portions in the first portion, The catheter according to claim 1 or 2, wherein the member is disposed on the flat portion.

5. The catheter according to any one of claims 1 to 4, wherein the height of the convex portion of the contrast marker is smaller than the thickness of the member.

6. the member is a wire connected at a distal end portion to a proximal end portion of the tubular member, The catheter according to any one of claims 1 to 5, wherein the contrast marker is disposed at a connection portion between the tubular member and the wire member.

7. the catheter is a support catheter that is used together with a treatment catheter and a guiding catheter for guiding the treatment catheter, and that guides a distal end portion of the treatment catheter to a treatment site; The support catheter a distal shaft as the tubular member into which the treatment catheter can be inserted; The catheter according to claim 6, further comprising a proximal shaft as the wire material.

8. The catheter according to any one of claims 1 to 7, wherein the cross section of the contrast marker further has a partial annular portion including a second portion that is within the remaining 2 / 3 of the circumference other than the first portion.

9. A method for manufacturing the catheter according to any one of claims 1 to 8, comprising the steps of: placing the contrast marker on the outer side of the inner layer before crimping; a step of placing a covering material on the outside of the contrast marker so as to cover a portion other than a portion where the convex portion is to be formed; applying an external force from the outside of the covering material to crimp the contrast marker to form the protrusion; removing the covering material and placing the member near the protrusion of the contrast marker; and covering the contrast marker and the member with the outer layer.

10. a pipe member having an outer layer and an inner layer; an annular contrast marker disposed between the outer layer and the inner layer such that its axial direction is substantially parallel to the axial direction of the tubular material; a member disposed between the outer layer and the contrast marker, a cross section of the radiopaque marker perpendicular to the axial direction has a convex portion that protrudes radially outward of the radiopaque marker; the convex portion is unevenly distributed in a first portion within a range of one-third of the outer periphery of the contrast marker in the cross section, a method for crimping a contrast marker when manufacturing a catheter, the method comprising: The vicinity of the convex portion means that, in the cross section, the angle around the axis between the apex of the convex portion and the center of the member in the circumferential direction of the contrast marker is within 90°, placing the contrast marker on the outer side of the inner layer before crimping; a step of placing a covering material on the outside of the contrast marker so as to cover a portion other than a portion where the convex portion is to be formed; applying an external force from the outside of the covering material to crimp the contrast marker to form the protrusion; removing the covering material and placing the member near the protrusion of the contrast marker; and covering the contrast marker and the member with the outer layer.

Images