Catheter

Abstract

Provided is a catheter which is capable of improving flexibility while maintaining kink resistance. The catheter (10) is provided with a tube including a reinforcing member (40) comprising a braided fabric, and the reinforcing member (40) has: a first spiral part (50) formed by winding first wires (51, 51) in a first spiral direction with a predetermined gap being formed between the first wires (51, 51), and a second spiral part (50) formed by winding the first wires (51, 51) in a second spiral direction with a predetermined gap being formed between the first wires (51, 51); and a second spiral portion (60) formed by winding a second wire (61) in a second spiral direction different from the first spiral direction, the second spiral portion (60) having a parallel contact portion (65) in which two second wires (61, 61) are arranged in parallel so as to be in contact with each other, and the parallel contact portion (65, 65) is formed by winding with a predetermined gap therebetween.

Description

Technical Field

[0001] The present invention relates to a catheter for injecting an anticancer agent or the like or for placing a stent or the like into tubular organs of the human body, such as blood vessels, bile ducts, pancreatic ducts, ureters, and trachea. Background Art

[0002] Conventionally, catheters were inserted into tubular organs such as blood vessels, ureters, bile ducts, and trachea, or into body cavities and other human tissues to inject contrast agents, anticancer agents, nutrients, etc., or to place stents and vascular occlusion devices in conjunction with guidewires.

[0003] Such a catheter is in the form of a tube made of a predetermined synthetic resin material, and may include a reinforcing member in order to improve rigidity, kink resistance, and the like.

[0004] For example, Patent Document 1 below describes a catheter having a shaft having an inner lumen extending from the distal end to the proximal end. The shaft of this catheter includes a reinforcement layer formed from a braid of fine wires, extending from the proximal end to the distal end. The braid is constructed by intersecting a first helical portion, formed from one or more wires wound in a first helical direction, and a second helical portion, formed from one or more wires wound in a second helical direction different from the first helical direction.

[0005] Furthermore, the wires constituting the first helical portion and the wires constituting the second helical portion are arranged with a predetermined gap therebetween, and the gap between the wires constituting the first helical portion is wider than the gap between the wires constituting the second helical portion (see Patent Document 1). Figure 4 ).

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2012-29872 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] In the catheter described in Patent Document 1, the first and second helical portions are formed by winding the wire with gaps therebetween over the entire axial region (from the proximal end portion to the distal end portion), and thus may have poor flexibility.

[0011] That is, since the wires constituting the two helical portions are separated by gaps, the wires in the two helical portions intersect with each other at more locations, and the area surrounded by the intersecting portions tends to be narrow. Therefore, although the catheter as a whole has high kink resistance, it tends to have poor flexibility.

[0012] Therefore, an object of the present invention is to provide a catheter having improved flexibility while maintaining kink resistance.

[0013] Solutions for solving problems

[0014] To achieve the above-mentioned object, the catheter of the present invention is a catheter having a tube including a reinforcing member formed of a braid, characterized in that the reinforcing member includes: a first helical portion formed by winding a first wire in a first helical direction with a predetermined gap therebetween; and a second helical portion formed by winding a second wire in a second helical direction different from the first helical direction, the second helical portion having a parallel contact portion in which at least two of the second wires are arranged in parallel in a contacting manner, the parallel contact portions being formed by winding with a predetermined gap therebetween.

[0015] Effects of the Invention

[0016] According to the present invention, the second spiral portion has a parallel contact portion formed by at least two second wires arranged in parallel in a contact manner, and the parallel contact portions are formed by winding with a specified gap between each other, so that the parallel contact portions can maintain resistance to kinking and can improve flexibility through the gaps between the parallel contact portions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 One embodiment of the catheter of the present invention is shown, which is an enlarged cross-sectional view of its main parts.

[0018] Figure 2 yes Figure 1 A-A sectional view.

[0019] Figure 3 This is an enlarged explanatory diagram of the main parts of the catheter of the present invention.

[0020] Figure 4 This is an explanatory diagram comparing a parallel contact portion consisting of two thin wires and a single thick wire in the catheter.

[0021] Figure 5 It is a schematic explanatory diagram of the flexibility test of Examples and Comparative Examples.

[0022] Figure 6 It is a graph showing the test results of the flexibility test.

[0023] Figure 7 It is a graph showing the test results of the kink resistance test of Examples and Comparative Examples. DETAILED DESCRIPTION

[0024] (One embodiment of a catheter)

[0025] Hereinafter, one embodiment of the catheter of the present invention will be described with reference to the drawings.

[0026] like Figure 1 As shown, the catheter 10 of this embodiment has a tube including a reinforcing member 40 made of braid. It should be noted that the tube has an inner cavity therein.

[0027] In this embodiment, the tube constituting the catheter 10 includes an inner layer 20 and an outer layer 30 disposed outside the inner layer 20 .

[0028] It should be noted that the “front end”, “front end”, and “front end side” in the catheter 10, tube, inner layer 20, outer layer 30, reinforcing member 40, first spiral portion 50, second spiral portion 60 and other components refer to the distal end, distal end, and distal end side that are farthest from the hand side of the catheter operator, and further, the “base end”, “base end”, and “base end side” refer to the proximal end, proximal end, and proximal end side that are closest to the hand side of the catheter operator. In addition, as Figure 1 As shown in the figure, the axis of the catheter 10 is referred to as the "axis C", and the direction along the axis C is referred to as the axial direction (the axial direction in each member has the same meaning).

[0029] like Figure 1 As shown, the inner layer 20 in this embodiment is composed of the following components: a base 21, which extends a specified length with a fixed diameter; a tapered portion 23, which gradually reduces in diameter and extends from the front end of the base 21 toward the front end of the inner layer 20; and a front end portion 25, which extends a specified length from the front end of the tapered portion 23 with a fixed diameter that is smaller than the outer diameter of the base 21.

[0030] The inner layer 20 may be made of, for example, fluorine-based resins such as polytetrafluoroethylene (PTFE), perfluoroalkoxy resin (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and tetrafluoroethylene-ethylene copolymer (ETFE), polyurethane, nylon elastomer, polyether block amide, polyethylene, polyvinyl chloride, vinyl acetate, ultraviolet curing resin, and resins used in adhesives (acrylic resins, polyurethane-based, epoxy-based, and silicone-based). It should be noted that the inner layer 20 in this embodiment is formed of polytetrafluoroethylene (PTFE).

[0031] On the other hand, the outer layer 30 includes a first layer 31 , a second layer 32 , a third layer 33 , a fourth layer 34 , and a fifth layer 35 continuously provided in the axial direction from the base end side of the tube toward the front end side.

[0032] Specifically, the first layer 31 is disposed within a predetermined range of the base portion 21 of the inner layer 20. Furthermore, the second layer 32 is disposed on the base portion 21 of the inner layer 20, closer to the distal end than the position where the first layer 31 is disposed. Furthermore, the third layer 33 is disposed within a range extending from a position closer to the distal end than the position where the second layer 32 is disposed on the base portion 21 of the inner layer 20, through the tapered portion 23, to the proximal end of the distal end portion 25.

[0033] The fourth layer 34 is arranged in a predetermined range from the distal end 25 of the inner layer 20 to the distal side of the third layer 33. The fifth layer 35 is arranged in the distal end 25 of the inner layer 20 to the distal side of the fourth layer 34.

[0034] Furthermore, the layers 31 to 35 constituting the outer layer 30 may be made of, for example, polyurethane, polyester, nylon elastomer, polyether block amide, polyethylene, polyvinyl chloride, vinyl acetate, ultraviolet curing resin, resins used for adhesives (acrylic resins, polyurethane series, epoxy series, silicone series), polytetrafluoroethylene (PTFE), perfluoroalkoxy resin (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE) and other fluororesins.

[0035] Furthermore, from the viewpoint of ensuring operability and torque transmission, the hardness of each layer 31 to 35 is set so that the first layer 31 is the hardest and gradually decreases toward the fifth layer 35 .

[0036] Furthermore, if Figure 1 As shown, an X-ray opaque marker 37 formed of an X-ray opaque metal such as W, Pt, Ti, Pd, Rh, Au, Ag, Bi, Ta, Ir and alloys thereof is embedded in the fifth layer 35 arranged on the front end side of the outer layer 30.

[0037] Furthermore, the outer periphery of the outer layer 30 is covered with a hydrophilic resin film 39 made of, for example, polyvinyl pyrrolidone, polyethylene glycol, or a methyl vinyl ether-maleic anhydride copolymer.

[0038] Next, the reinforcing member 40 will be described in detail.

[0039] like Figure 3As shown, the reinforcing member 40 includes: a first spiral portion 50 formed by winding a first wire 51 in a first spiral direction with a predetermined gap therebetween; and a second spiral portion 60 formed by winding a second wire 61 in a second spiral direction different from the first spiral direction (the second wire 61 is wound in the second spiral direction different from the first spiral direction so as to be arranged so as to intersect with the first wire 51 of the first spiral portion 50). It should be noted that in the case of this embodiment, the first wire 51 and the second wire 61 are both round wires with a circular cross-section.

[0040] Figure 2 yes Figure 1 The cross-sectional view taken along the AA line of sight is a cross-sectional view when the catheter 10 is cut at a predetermined position on the distal end side and viewed from the base end side toward the distal end side. Figure 3 FIG. 3 shows a state where the outer layer 30 is removed. Figure 3 In the figure, the right side of the drawing is the base end side of the catheter 10, and the left side of the drawing is the front end side of the catheter 10.

[0041] In addition, the above-mentioned first spiral direction R1 (hereinafter, also referred to as “first spiral direction R1”) is determined by the inclination angle θ1 of the first wire 51 relative to the axis C of the catheter 10 and the winding direction of the first wire 51. On the other hand, the second spiral direction R2 (hereinafter, also referred to as “second spiral direction R2”) is determined by the inclination angle θ2 of the second wire 61 relative to the axis C of the catheter 10 and the winding direction of the second wire 61.

[0042] That is, Figure 3 As shown, the first spiral portion 50 is formed by tilting the first wire 51 relative to the axis C of the catheter 10 at a predetermined angle θ1. Figure 2 As shown, when the reinforcing member 40 is viewed from the proximal end side toward the distal end side of the catheter 10 , the first wire 51 is spirally wound in a right-hand (clockwise) manner.

[0043] Furthermore, the first wires 51 and 51 are separated from each other by a predetermined gap S1 in the axial direction of the first spiral portion 50 (see Figure 3 The gap S1 at the front end side of the first spiral portion 50 is wider than the gap S1 at the base end side. Figure 3 For the sake of convenience, the middle part of the first spiral portion 50 is shown. In this middle part, the gap S1 between the first wires 51 and 51 is substantially constant, but the gap S1 between the first wires 51 and 51 is substantially constant. Figure 3 The middle part shown is closer to the base end ( Figure 3 The gap S1 is larger than that of Figure 3 The middle part shown is closer to the front end ( Figure 3The gap S1 is wide (in the middle, on the left).

[0044] It should be noted that the gap S1 refers to a predetermined side edge ( Figure 3 The tangent line at the right side edge) is adjacent to the other side edge ( Figure 3 The length between the tangents at the side edge on the left.

[0045] Furthermore, the gap S1 between the first wires 51 and 51 of the first spiral portion 50 is preferably 0.03 to 0.25 mm, and more preferably 0.06 to 0.20 mm.

[0046] Furthermore, the first spiral portion 50 in this embodiment is composed of eight first wires 51a, 51b, 51c, 51d, 51e, 51f, 51g, and 51h, which are wound while maintaining a predetermined gap S1 in the axial direction of the first spiral portion 50.

[0047] Here, the first wires 51a, 51b, 51c, 51d, 51e, 51f, 51g, and 51h are arranged in order from the distal end to the proximal end of the first coil portion 50. The first wire 51a is arranged again after the first wire 51h.

[0048] Furthermore, the angle θ1 of the first wire 51 forming the first spiral portion 50 relative to the axis C of the catheter 10 is preferably 100 to 140°, and more preferably 110 to 130°.

[0049] On the other hand, Figure 3 As shown, the second spiral portion 60 is formed by tilting the second wire 61 relative to the axis C of the catheter 10 at a predetermined angle θ2. Figure 2 As shown, when the reinforcing member 40 is viewed from the base end side toward the front end side of the catheter 10, the second wire 61 is wound into a spiral in a left-handed (counterclockwise) manner in a direction different from the first spiral direction R1, here in the opposite direction to the first spiral direction R1.

[0050] Furthermore, the second spiral portion 60 includes a parallel contact portion 65 in which at least two second wires 61 are arranged in parallel so as to contact each other. The parallel contact portions 65 and 65 are wound with a predetermined gap therebetween.

[0051] In the case of this embodiment, if Figure 3 As shown, the two second wires 61 , 61 are arranged side by side in a manner of contacting each other (the second wires 61 , 61 are arranged side by side in a manner of contacting each other without a gap), thereby constituting a parallel contact portion 65 .

[0052] More specifically, one side edge ( Figure 3 In the embodiment, the side edge of the right side of the second wire 61 arranged on the left side of the two second wires 61, 61 constituting the parallel contact portion 65 and the other side edge in the width direction of the second wire 61 arranged adjacent to the second wire 61 in the axial direction of the second spiral portion 60 ( Figure 3 In the embodiment, the side edges of the left side of the second wire 61 on the right side of the two second wires 61, 61 constituting the parallel contact portion 65 are in contact with each other, thereby constituting a parallel contact portion 65 as a whole consisting of two wires as a group.

[0053] Furthermore, the parallel contact portions 65, 65, which constitute a set of two, are separated from each other by a predetermined gap S2 in the axial direction C of the second spiral portion 60 (see Figure 3 The gap S2 at the front end side of the second spiral portion 60 is wider than the gap S2 at the base end side. Figure 3 For the sake of convenience, the middle part of the second spiral portion 60 is shown. In this middle part, the gap S2 between the second wires 61 and 61 is substantially constant, but the gap S2 between the second wires 61 and 61 is substantially constant. Figure 3 The middle part shown is closer to the base end ( Figure 3 The gap S2 is larger than that of Figure 3 The middle part shown is closer to the front end ( Figure 3 center, left side) gap S2.

[0054] It should be noted that the gap S2 refers to the side edge ( Figure 3 The tangent line at the side edge of the second wire 61 on the right side of the predetermined parallel contact portion 65 and the other side edge ( Figure 3 , the length between the tangent lines at the side edge of the second wire material 61 constituting the left side of the other parallel contact portion 65).

[0055] Furthermore, the gap S2 between the parallel contact portions 65 and 65 of the second spiral portion 60 is preferably 0.06 to 0.50 mm, and more preferably 0.12 to 0.40 mm.

[0056] Furthermore, the second spiral portion 60 in this embodiment is composed of eight second wires 61a, 61b, 61c, 61d, 61e, 61f, 61g, and 61h. The second wire 61a and the second wire 61b are in contact with each other, the second wire 61c and the second wire 61d are in contact with each other, the second wire 61e and the second wire 61f are in contact with each other, and the second wire 61g and the second wire 61h are in contact with each other, thereby forming a parallel contact portion 65 consisting of two wires in a group, which is formed by maintaining a specified gap S2 in the axial direction of the second spiral portion 60 and being wound.

[0057] Here, the second wires 61a, 61b, 61c, 61d, 61e, 61f, 61g, and 61h are arranged in this order from the distal end toward the proximal end of the second coil 60, and this combination constitutes a parallel contact portion 65. It should be noted that after the parallel contact portion 65 formed by the second wires 61g and 61h, another parallel contact portion 65 formed by the second wires 61a and 61b is arranged.

[0058] In addition, if Figure 3 As shown, in the case of this embodiment, the parallel contact portion 65 composed of two second wires 61, 61 in contact with each other is located on the outside (radially outside) of the first wire 51 at two specified locations in the direction of travel of the second spiral direction R2, is located on the inside (radially inside) of the first wire 51 at the following two locations, and is located on the outside of the first wire 51 again at the following two locations. Thereafter, as the inside, outside, and inside of the first wire 51 are alternately located on the outside and inside of the first wire 51, the second spiral portion 60 is woven while crossing the first wire 51 of the first spiral portion 50, thereby forming the second spiral portion 60.

[0059] Furthermore, in this embodiment, the gap S2 between the parallel contact portions 65 , 65 of the second spiral portion 60 is set to be wider than the gap S1 between the first wires 51 , 51 of the first spiral portion 50 .

[0060] In addition, if Figure 3 As shown, the space K1 formed by the cross-arrangement of multiple first wires 51 of the first spiral portion 50 and multiple second wires 61 of the second spiral portion 60 is roughly parallelogram-shaped (the parallel contact portions 65, 65 are arranged on the short side, and the first wires 51, 51 are arranged on the long side, which is the area surrounded by them), and the roughly parallelogram-shaped space K1 is arranged from the front end of the reinforcing member 40 to the entire area of the base end.

[0061] It should be noted that each space K1 is configured such that the area on the front end side of the reinforcing member 40 is narrower than the area on the base end side. Figure 3In the figure, for the sake of convenience, the middle part of the reinforcing member 40 is shown, and the areas of the spaces K1 in the middle part are roughly the same, but the areas of the spaces K1 are larger than those in the figure. Figure 3 The middle part shown is closer to the front end ( Figure 3 The area of each space K1 on the left side is smaller than Figure 3 The middle part shown is closer to the base end ( Figure 3 The area of each space K1 (in the middle and right sides).

[0062] Furthermore, in this embodiment, the number of the first wires 51 forming the first coil portion 50 is set to be the same as the number of the second wires 61 forming the second coil portion 60 .

[0063] As described above, in the case of this embodiment, the first wires 51 forming the first spiral portion 50 are eight first wires 51a, 51b, 51c, 51d, 51e, 51f, 51g, and 51h, and the second wires 61 forming the second spiral portion 60 are also eight second wires 61a, 61b, 61c, 61d, 61e, 61f, 61g, and 61h, which are the same number.

[0064] In addition, if Figure 2 As shown, the catheter 10 is configured so that at least the parallel contact portion 65 contacts the outer periphery of the inner layer 20, and the catheter 10 is constructed so that the outer layer 30 does not enter between the outer periphery of the inner layer 20 and the second wires 61, 61 forming the parallel contact portion 65 configured in contact with the outer periphery.

[0065] In this embodiment, the parallel contact portion 65 formed by the two second wires 61, 61 is arranged in contact with the outer periphery of the inner layer 20. As a result, a predetermined gap K2 is defined between the outer periphery of the inner layer 20 and the second wires 61, 61 forming the parallel contact portion 65, and the outer layer 30 is prevented from entering this gap K2. It should be noted that the first wire 51 is also arranged in contact with the outer side (radially outward) of the two second wires 61, 61.

[0066] In addition, if Figure 2 As shown, the outer layer 30 enters the outside of the second wires 61, 61 and the first wire 51 that constitute the parallel contact portion 65, and the outer layer 30 also enters the space K1 formed by the intersection of the wires 51, 61. In other words, the second wires 61, 61 and the first wire 51 are buried within the outer layer 30. As a result, the displacement (radially outward displacement and circumferential displacement) of the second wires 61, 61 and the first wire 51 relative to the inner layer 20 is restricted.

[0067] In this embodiment, as described above, the parallel contact portions 65 are arranged in a weave pattern that intersects the first wire 51, alternating between the outside and inside of the first wire 51 (see paragraph 0046). Therefore, the parallel contact portions 65 have portions that contact the outer periphery of the inner layer 20 and portions that do not contact them along the spiral trajectory in the second spiral direction R2 of the second spiral portion 60. That is, the parallel contact portions 65 do not all abut against the outer periphery of the inner layer 20, but rather, the portions that abut and the portions that do not abut are positioned alternately along the spiral trajectory in the second spiral direction R2.

[0068] In addition, if Figure 1 As shown, the reinforcing member 40 is not positioned at the distal end of the inner layer 20, but rather is positioned in a range from a predetermined position in the inner layer 20 to just before the distal end. In other words, the reinforcing member 40 is not positioned at the distal end of the outer layer 30. As a result, the flexibility of the distal end of the catheter 10 is maintained.

[0069] Note that the angle θ2 of the second wire 61 forming the second spiral portion 60 with respect to the axis C of the catheter 10 is preferably 100 to 140°, and more preferably 110 to 130°.

[0070] As the first wire 51 of the first coil 50 and the second wire 61 of the second coil 60 of the reinforcing member 40 of the structure described above, for example, stainless steel or piano wire can be used. Alternatively, superelastic alloys such as Ni-Ti alloys, Ni-Ti-X (X = Fe, Cu, V, Co, Cr, Mn, Nb, etc.) alloys, and Cu-Zn-X (X = Al, Fe, etc.) alloys can be used. Alternatively, X-ray opaque metals composed of W, Pt, Ti, Pd, Rh, Au, Ag, Bi, Ta, and alloys thereof can be used. In this embodiment, the first wire 51 and the second wire 61 are W.

[0071] The wire diameters of the first and second wires 51 and 61 are preferably 0.010 to 0.050 mm, more preferably 0.015 to 0.030 mm. The outer diameter of the reinforcing member 40 is preferably 0.40 to 5.00 mm, more preferably 0.50 to 1.00 mm.

[0072] (Variation)

[0073] The shapes, structures, materials, layouts, etc. of the components constituting the catheter described above, such as the tube, inner layer, outer layer, reinforcing member, first helical portion, and second helical portion, are not limited to those described above.

[0074] In the case of this embodiment, the inner layer 20 has a shape having a tapered portion 23, but as the inner layer, it can also be a shape extending from the base end to the front end with a fixed diameter, or a shape in which multiple cylindrical portions with different outer diameters extending with a fixed diameter are continuously arranged in the axial direction (a shape with a stepped outer periphery), or a shape in which a cylindrical portion extending with a fixed diameter is combined with a tapered portion.

[0075] In this embodiment, the outer layer 30 is formed by continuously providing layers 31, 32, 33, 34, and 35 having different hardnesses in the axial direction. Alternatively, the outer layer may be a single layer made of the same material from the base end to the tip end.

[0076] Furthermore, in the case of this embodiment, the first spiral direction R1 of the first spiral portion 50 constituting the reinforcing member 40 is clockwise, and the second spiral direction R2 of the second spiral portion 60 is counterclockwise. For example, on the basis of setting the first spiral direction R1 of the first spiral portion and the second spiral direction R2 of the second spiral portion to be clockwise or counterclockwise, the inclination angle θ1 of the first wire 51 relative to the axis C of the catheter 10 and the inclination angle θ2 of the second wire 61 relative to the axis C of the catheter 10 can be different angles, as long as the first spiral direction R1 and the second spiral direction R2 are different.

[0077] In this embodiment, two second wires 61 are arranged in parallel so as to contact each other, thereby forming the parallel contact portion 65 . However, three or more second wires 61 may form the parallel contact portion.

[0078] Furthermore, in this embodiment, the gap S2 between the parallel contact portions 65, 65 of the second spiral portion 60 is set to be wider than the gap S1 between the first wires 51, 51 of the first spiral portion 50. The gap S2 may be narrower than the gap S1, or the two gaps S1 and S2 may be the same.

[0079] In addition, the number of first wires 51 forming the first spiral portion 50 and the number of second wires 61 forming the second spiral portion 60 are set to be the same, the number of first wires and the number of second wires can also be different, and the number of one of the first wires or the second wires can also be more or less than the number of the other.

[0080] Furthermore, in the case of this embodiment, the braiding pattern of the parallel contact portion 65 with respect to the first wire 51 is such that, in the direction of travel in the second spiral direction R2, there are two alternate crossings on the outside and inside of the first wire 51 (see FIG. Figure 3 ), for example, it may be a weaving pattern with an alternating cross pattern on the outside and inside of the first wire.

[0081] In addition, in the case of this embodiment, as for the gap S1 between the first wires 51, 51 of the first spiral portion 50, the base end side of the first spiral portion 50 is wider than the front end side. The gap S1 can also be, for example, fixed in the entire axial area from the base end to the front end of the first spiral portion 50, or the front end side of the first spiral portion 50 is wider than the base end side, or gradually widens or narrows from the base end of the first spiral portion 50 toward the front end.

[0082] Furthermore, in the case of this embodiment, with respect to the gap S2 between the parallel contact portions 65, 65 of the second spiral portion 60, the base end side of the second spiral portion 60 is wider than the front end side. The gap S2 may be, for example, fixed in the entire axial area from the base end to the front end of the second spiral portion 60, or the front end side of the second spiral portion 60 may be wider than the base end side, or the width may gradually widen or narrow from the base end toward the front end of the second spiral portion 60.

[0083] (Effect)

[0084] Next, an example of a method of using the catheter of the present invention based on the above-mentioned results, and its effects and benefits will be described.

[0085] This catheter 10 is used, for example, to inject contrast agents, anticancer agents, etc., or to place stents, etc., into predetermined locations of human tissue, such as blood vessels such as the hepatic artery, bile ducts, pancreatic ducts, ureters, and trachea, or tubular organs, such as body cavities. It should be noted that the catheter 10 can also be used in locations other than those listed above, and the location of use is not particularly limited.

[0086] First, after a contrast medium is administered into the body, the catheter 10 is guided and moved via a guide wire (not shown) under X-ray transmission (radiotransmission) by a known Seldinger method or the like.

[0087] In this case, it is sometimes desirable to select a specific small-diameter tubular organ from a plurality of small-diameter tubular organs branching from a large-diameter tubular organ and guide it through the catheter 10. To achieve this, the catheter 10 must be flexible. Furthermore, in order to ensure that a liquid anticancer agent or other drug reaches the affected area reliably, the catheter 10 must be kink-resistant and maintain its inner lumen.

[0088] In contrast, in the catheter 10 of the present invention, as described above, the second spiral portion 60 includes the parallel contact portion 65 where at least two second wires 61 , 61 are arranged in parallel so as to contact each other. The parallel contact portions 65 , 65 are wound with a predetermined gap therebetween.

[0089] Therefore, in the parallel contact portion 65 , the kink resistance of the catheter 10 is maintained, and the flexibility of the catheter 10 can be improved by the gap between the parallel contact portions 65 , 65 .

[0090] Therefore, the above requirements (maintaining kink resistance and improving flexibility) can be met. Therefore, for example, it can be preferably used in cases where the catheter 10 is inserted into the hepatic artery and an anticancer drug is injected into the liver through the hepatic artery during treatment of liver cancer.

[0091] Furthermore, to maintain the kink resistance of the catheter 10, for example, the second wire 61 forming the second coil 60 may be formed as a single thick wire. However, in this case, the kink resistance of the catheter 10 can be maintained, but the flexibility of the catheter 10 is likely to decrease.

[0092] In contrast, the catheter 10 of the present invention has a parallel contact portion 65 in which at least two second wires 61 forming the second spiral portion 60 are arranged in parallel in a contact manner. Therefore, it is as if the multiple wires are treated as a whole, and the same kink resistance as when a single thick wire is used can be obtained. While maintaining the kink resistance, a thin wire that is more flexible than a thick wire can be used, and the flexibility of the catheter 10 can be improved by the gap S2 between the parallel contact portions 65, 65.

[0093] Furthermore, compared with a single thick wire, the arrangement of at least two second wires 61, 61 in contact with each other can suppress the increase in the outer diameter. Figure 4 As shown, when comparing the width ( Figure 4 In the case of a thick wire with the same outer diameter as the one in the paper, the outer diameter direction dimensions ( Figure 4 On paper, it refers to the vertical dimension. Figure 4 As a result, the outer diameter of the catheter 10 can be reduced.

[0094] Furthermore, in this embodiment, the gap S2 between the parallel contact portions 65 , 65 of the second spiral portion 60 is set to be wider than the gap S1 between the first wires 51 , 51 of the first spiral portion 50 .

[0095] According to the above embodiment, since the gap S2 is set as described above, the space K1 formed by the second wire 61 of the second helical portion 60 intersecting the first wire 51 of the first helical portion 50 can be kept wide, further improving the flexibility of the catheter 10. Furthermore, the number of second wires 61 of the second helical portion 60 in a predetermined region can be made close to the number of first wires 51 of the first helical portion 50, which also improves the flexibility of the catheter 10 from this perspective.

[0096] Furthermore, in this embodiment, the number of the first wires 51 forming the first coil portion 50 and the number of the second wires 61 forming the second coil portion 60 are set to be the same.

[0097] According to the above embodiment, the number of first wires 51 forming the first helical portion 50 is equal to the number of second wires 61 forming the second helical portion 60 , thereby facilitating the widening of the gaps between the parallel contact portions 65 , 65 in the second helical portion 60 , and further enhancing the flexibility of the catheter 10 .

[0098] In addition, in this embodiment, the tube includes an inner layer 20 and an outer layer 30 arranged outside the inner layer 20, and is arranged so that at least the parallel contact portion 65 contacts the outer periphery of the inner layer 20, and is configured so that the outer layer 30 does not enter between the outer periphery of the inner layer 20 and the second wires 61, 61 forming the parallel contact portion 65 arranged in contact with the outer periphery (see Figure 2 ).

[0099] According to the above embodiment, the outer layer 30 is configured so as not to enter between the outer periphery of the inner layer 20 and the second wires 61, 61 constituting the parallel contact portion 65 arranged in contact with the outer periphery. Therefore, the second wires 61, 61 constituting the parallel contact portion 65 are not completely restrained from each other and can be displaced to a certain extent. Therefore, the flexibility of the reinforcing member 40 can be improved, and the flexibility of the catheter 10 can be improved.

[0100] Example

[0101] (Example)

[0102] Made with Figures 1 to 3 The catheter of the embodiment has the same shape and structure. The first helical portion 50 and the second helical portion 60 are formed by winding eight first wires 51 and eight second wires 61, respectively.

[0103] (Comparative Example)

[0104] Eight first and second wires were wound to form the first and second helical portions, respectively. The inclination angle θ1 of the first wire and the inclination angle θ2 of the second wire relative to the catheter axis were set to the same angles as those in the embodiment. Furthermore, a comparative example catheter having a second helical portion was manufactured in which the second wires were wound with gaps in the axial direction without contact with each other.

[0105] (Flexibility confirmation test)

[0106] like Figure 5 As shown, the catheters of the Examples and Comparative Examples were each placed in a known indentation load measuring machine 100. The distal end of each catheter was fixed 4 mm from the end face of the indentation load measuring machine 100. An indentation load F was then applied at a predetermined speed, 1 mm from the distal end of each catheter, for a penetration of 0.5 mm. The rebound load (resistance load) at this point was measured. This test was performed three times for each catheter of the Examples and Comparative Examples.

[0107] The results are shown in Figure 6 .exist Figure 6 If the rebound load is small, it means the flexibility is high. Figure 6 As shown, it can be seen that the rebound load of the embodiment is smaller than that of the comparative example, and the flexibility of the embodiment is higher than that of the comparative example.

[0108] (Kinking resistance test)

[0109] Using a specified measuring tool capable of gripping an object, the distal end of the catheters of the Examples and Comparative Examples was clamped into a U-shape. The amount of clamping applied to the measuring tool was gradually reduced, and the outer diameter was measured each time the clamping amount reached a specified value. This test was performed three times for each of the catheters of the Examples and Comparative Examples.

[0110] The results are shown in Figure 7 . Figure 7 The horizontal axis in is the amount of insertion of each catheter based on the measuring piece. Figure 7 The vertical axis in the figure represents the outer diameter retention rate, which indicates the ratio of the outer diameter of the catheter to the outer diameter at the start of the test (initial outer diameter / measurement outer diameter×100). If the outer diameter retention rate decreases, kinking can be considered to have occurred.

[0111] like Figure 7 As shown, the catheter of the example and the catheter of the comparative example have approximately the same tendency of decreasing outer diameter retention rate. Therefore, it can be seen that the catheter of the example has approximately the same kink resistance as the catheter of the comparative example.

[0112] It should be noted that the present invention is not limited to the above-described embodiment, and various modified embodiments are possible within the scope of the gist of the present invention, and such embodiments are also included in the scope of the present invention.

[0113] Description of Reference Numerals

[0114] 10: catheter;

[0115] 20: inner layer;

[0116] 30: outer layer;

[0117] 40: Reinforcement member;

[0118] 50: first spiral portion;

[0119] 51: first wire;

[0120] 60: second helical portion;

[0121] 61: second wire;

[0122] 65: Parallel contact part.

Claims

1. A catheter having a tube including a reinforcing member composed of a braid, characterized in that The reinforcing member has: a first spiral portion formed by winding a first wire material in a first spiral direction with a predetermined gap therebetween; and The second helical portion is formed by winding a second wire in a second helical direction different from the first helical direction. The second spiral portion includes a parallel contact portion in which at least two of the second wires are arranged in parallel so as to be in contact with each other, and the parallel contact portions are formed by being wound with a predetermined gap therebetween.

2. The catheter according to claim 1, wherein The gap between the parallel contact portions of the second spiral portion is set to be wider than the gap between the first wires of the first spiral portion.

3. The catheter according to claim 1 or 2, wherein: The number of the first wires forming the first spiral portion is the same as the number of the second wires forming the second spiral portion.

4. The catheter according to claim 1 or 2, wherein: The tube comprises: an inner layer; and an outer layer disposed outside the inner layer. The conduit is configured such that at least the parallel contact portion contacts the outer periphery of the inner layer, The catheter is configured so that the outer layer does not enter between the outer periphery of the inner layer and the second wire material constituting the parallel contact portion disposed in contact with the outer periphery.

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