JP2012061070A - Catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter capable of achieving a proper balance between the flexibility of bending and the degree of strength.SOLUTION: The catheter 10 includes a reinforcement layer 50 formed in the outer circumference of a lumen 21. The reinforcement layer 50 is formed of wires 51 and 52, which are wound in multiple lines and have a plurality of kinds of cross sections. Therefore, for example, spiral projection parts corresponding to the wire 52 with a large diameter are formed in the outer layer 64 positioned on the outer circumferential face of the reinforcement layer 50, and forward/backward thrusting force can be caused by turning the whole of the catheter 10. Since the wires 51 and 52 of the plurality of kinds are positioned inside the outer layer 64, the wire 51 with a small diameter can be easily displaced, and consequently, the catheter can be bent easily.

Description

  The present invention relates to a catheter in which a reinforcing layer is formed on the outer periphery of a lumen, and more particularly to a catheter made of a wire in which the reinforcing layer is wound in a coil shape.

  In recent years, there is a catheter in which a reinforcing layer is formed on the outer periphery of the lumen, and in particular, there is a catheter made of a wire in which the reinforcing layer is wound in a coil shape. In such a catheter, by pulling a slide operation line inserted through the sheath, the distal end portion of the sheath can be bent and the approach direction into the body cavity can be variably operated.

  With regard to this type of technology, a small-diameter operation wire tubule is arranged on the outer periphery of a large-diameter large-diameter resin tube, and a slide operation line is slidably inserted into the operation wire tubule so that the tip is distal to the large-diameter resin tube. There has been proposed a catheter that is connected to an end portion and encloses a large-diameter resin tube together with an operation wire thin tube with a reinforcing layer made of a mesh-like blade (Patent Document 1).

Special table 2009-537244 gazette

  However, since the mesh-shaped blade crosses the wires, the free bending of the catheter is hindered. On the other hand, in a catheter made of a wire in which the reinforcing layer is wound in a coil shape, good flexibility and kink resistance are realized.

  However, even with a catheter having such a reinforcing layer, it is not easy to achieve an appropriate balance between flexibility and torque transmission (torsional rigidity), for example, it is difficult to smoothly insert it into a human blood vessel or body cavity. There is something wrong.

  The present invention has been made in view of the above-described problems, and provides a catheter capable of making an appropriate balance between flexibility and torque transmission.

  The catheter of the present invention is a catheter in which a reinforcing layer is formed on the outer periphery of the lumen, and the reinforcing layer is formed by winding a plurality of types of wires having different cross-sectional shapes orthogonal to the longitudinal direction of the wire in multiple strands. Yes.

  Therefore, in the catheter of the present invention, the reinforcing layer formed on the outer periphery of the lumen is composed of a plurality of types of cross-sectional wires wound in multiple strands. For this reason, desired flexibility and torque transmission are realized by a plurality of types of cross-section wires.

  In the above-described catheter, the plurality of types of wires may have different cross-sectional areas orthogonal to the longitudinal direction.

  In the catheter as described above, the plurality of types of wires may have different diameters.

  Further, the catheter as described above further includes an inner layer in which a lumen is formed on the inner side and a reinforcing layer is formed on the outer periphery, and a plurality of types of wires of the reinforcing layer are provided on at least a part of the entire length of the inner layer. It may be wound on the surface.

  Further, the catheter as described above further includes an outer layer in which a reinforcing layer is formed on the inner side, and a convex portion corresponding to a large-diameter wire is formed on the outer peripheral surface of the outer layer in at least a part of the entire length. May be.

  In the catheter as described above, a plurality of types of wires of the reinforcing layer may be tightly wound on the outer peripheral surface of the inner layer on the proximal end side of the entire length.

  In the catheter as described above, at least a part of the small-diameter wire of the reinforcing layer may be held in pressure contact with the outer peripheral surface of the inner layer by the large-diameter wire.

  Further, the catheter as described above further includes a cylindrical outer layer having a reinforcing layer formed on the inside thereof, and plural types of wires of the reinforcing layer are wound on the inner peripheral surface of the outer layer at least at a part of the entire length. It may be turned.

  In the catheter as described above, a plurality of types of wires of the reinforcing layer may be wound on the inner peripheral surface of the outer layer on the distal end side of the entire length.

  A large-diameter wire and a small-diameter wire may be tightly wound on the inner peripheral surface of the outer layer, and the small-diameter wire may be separated from the inner layer.

  The various components of the present invention do not necessarily have to be independent of each other. A plurality of components are formed as a single member, and a single component is formed of a plurality of members. It may be that a certain component is a part of another component, a part of a certain component overlaps with a part of another component, or the like.

  In addition, the wire having a plurality of types of cross-sectional shapes referred to in the present invention is, for example, a wire having a cross-sectional shape of a perfect circle and a rectangle, a similar-shaped wire having a different diameter in a perfect circle, the same shape and a vertically long direction. It also means a rectangular wire that is different from a landscape.

  In the catheter of the present invention, the reinforcing layer formed on the outer periphery of the lumen is composed of a plurality of types of cross-sectional wires wound in multiple strands. For this reason, desired flexibility and torque transmission can be realized by a plurality of types of cross-section wires.

It is a typical vertical side view which shows the internal structure of the front-end | tip part of the catheter of embodiment of this invention. It is a typical vertical front view which shows the internal structure of the front-end | tip part of a catheter. It is a typical vertical side view which shows the internal structure of the base end part of a catheter. It is a typical vertical side view which shows the internal structure of the front-end | tip part of the catheter of one modification. It is a typical vertical side view which shows the internal structure of the base end part of the catheter of one modification.

  An embodiment of the present invention will be described below with reference to the drawings. In the present embodiment, description will be made by defining the front-rear, left-right, up-down directions as shown. However, this is provided for the sake of convenience in order to briefly explain the relative relationship between the components. Therefore, the direction at the time of manufacture and use of the product which implements the present invention is not limited.

  As shown in FIGS. 1 to 3, the catheter 10 of the present embodiment is a catheter 10 in which a reinforcing layer 50 is formed on the outer periphery of the lumen 21, and the reinforcing layer 50 is formed in the longitudinal direction of the wires 51 and 52. A plurality of types of wires 51 and 52 having different cross-sectional shapes orthogonal to each other are wound in multiple strips. Since the plurality of types of wires 51 and 52 have different diameters, their cross-sectional areas orthogonal to the longitudinal direction are different.

  Further, the catheter 10 of the present embodiment has a cylindrical inner layer 20 in which the lumen 21 is formed on the inner side and the reinforcing layer 50 is formed on the outer periphery, and the proximal end is at least a part of the entire length. On the side, a plurality of types of wires 51 and 52 of the reinforcing layer 50 are tightly wound on the outer peripheral surface of the inner layer 20.

  Furthermore, the catheter 10 of the present embodiment has a cylindrical outer layer 64 in which the reinforcing layer 50 is formed inside, and a convex portion 65 corresponding to the large-diameter wire 52 is formed on the outer peripheral surface of the outer layer 64. Has been.

  In the catheter 10 of the present embodiment, one large-diameter wire 52 is wound around two small-diameter wires 51, and the small-diameter wire 51 of the reinforcing layer 50 is formed by the large-diameter wire 52. It is held in pressure contact with the outer peripheral surface of the inner layer 20.

  Further, in the catheter 10 of the present embodiment, as shown in FIG. 1, a plurality of types of wires 51 and 52 of the reinforcing layer 50 are wound on the inner peripheral surface of the outer layer 64 on the distal end side which is at least a part of the entire length. It has been turned.

  More specifically, in the catheter 10 of the present invention, as shown in FIGS. 1 and 2, an inner layer 20 made of a large diameter resin tube in which a large diameter lumen 21 is formed, and an inner layer at least at the distal end portion. At least one small-diameter operation line capillary 30 (a, b) positioned outside of 20, and is slidably inserted into the operation line capillary 30 (a, b). And a reinforcing layer 50 that is wound in a coil shape integrally with the inner layer 20 and the operating wire thin tube 30 (a, b).

  In the catheter 10 of the present embodiment, separate operation line tubules 30 (a, b) made of polyetheretherketone (PEEK) or the like are arranged outside the inner layer 20 made of a fluorine coat layer, etc. Wires 51 and 52 of a reinforcing layer 50 are wound around the operation wire capillary 30 (a, b) and the inner layer 20.

  As shown in FIG. 1, the reinforcing layer 50 has wires 51 and 52 wound around a space at the distal end portion of the sheath 16 to facilitate bending, and the proximal end of the sheath 16. The wires 51 and 52 are tightly wound around the part or the like in order to restrict bending.

  The gap between the reinforcing layers 50 located between the inner layer 20 and the outer layer 64 is sealed with a reinforcing resin layer 60 made of resin, thereby forming the sheath 16. The sheath 16 is a flexible tubular body that is inserted into a body cavity through an endoscope or directly, and is inserted into a blood vessel such as a celiac artery and a peripheral blood vessel such as a hepatic artery branch or an internal carotid artery branch. The

  The outer layer 64 is formed of a hydrophilic resin layer that is lubricated on the outer surface as the outermost layer of the catheter 10. For the outer layer 64, a hydrophilic material such as polyvinyl alcohol (PVA) or polyvinyl pyrrolidone can be used.

  Here, typical dimensions of the sheath 16 of the present embodiment will be exemplified. The outermost diameter of the sheath 16 is less than 1 mm in diameter, specifically about 700 to 900 μm. The inner layer 20 has an inner diameter of about 400 to 600 μm, a thickness of about 10 to 30 μm, the reinforcing resin layer 60 has a thickness of about 100 to 150 μm, and the diameters of the wires 51 and 52 are 20 to 100 μm. Further, the inner diameter of the operation wire capillary 30 (a, b) is 40 to 100 μm, and the thickness of the slide operation wire 40 (a, b) is 30 to 60 μm.

  A thermoplastic polymer is widely used for the reinforcing resin layer 60. Examples include polyimide (PI), polyamideimide (PAI), polyethylene terephthalate (PET), polyethylene (PE), polyamide (PA), nylon elastomer, polyurethane (PU), ethylene-vinyl acetate resin (EVA), poly Vinyl chloride (PVC) or polypropylene (PP) can be used.

  For the wires 51 and 52 of the reinforcing layer 50, fine wires of polymer fibers such as polyimide, polyamideimide, polyethylene terephthalate, etc. can be used in addition to fine metal wires such as stainless steel (SUS) and nickel titanium alloy.

  The cross-sectional shape of the wires 51 and 52 of the reinforcing layer 50 is not particularly limited, and may be a circle, an ellipse, a square, a rectangle, a polygon, or the like, but is a general circle in the present embodiment.

  However, multiple types of wires only need to have different cross-sectional secondary moments.For example, a round wire and an elliptical wire may be combined, or the same rectangular wire may be vertically long and horizontally long (not shown). )

  The operation wire thin tubes 30 a and 30 b are held by the reinforcing layer 50 along the outer peripheral surface of the inner layer 20. That is, inside the reinforcing resin layer 60 and the reinforcing layer 50, the operation wire thin tubes 30a and 30b are embedded extending in the longitudinal direction, and the slide operation wires 40 (a, b) are slidably inserted into each of them. Has been.

  Further, a part or the whole of the operation wire tubule 30 (a, b) may be provided spirally with respect to the sheath 16, and may include a circumferential component together with a longitudinal component. Hereinafter, the slide operation line 40a may be referred to as a first slide operation line, and the slide operation line 40b may be referred to as a second slide operation line.

  In the catheter 10 of the present embodiment, the pair of operation line tubules 30a and 30b through which the slide operation lines 40a and 40b are respectively inserted are arranged facing the periphery of the inner layer 20.

  In other words, in the present embodiment, the operation line tubule 30a and the operation line tubule 30b are formed to be opposed to each other by 180 degrees across the axis of the catheter 10. The slide operation line 40a is inserted through the operation line capillary 30a, and the slide operation line 40b is inserted through the operation line capillary 30b.

  The operating wire tubules 30 (a, b) can be formed integrally on the outer peripheral surface of the inner layer 20 by being extruded together with the resin material constituting the inner layer 20. The material of the operation wire capillary 30 (a, b) is superior in heat resistance to the resin material of the reinforcing resin layer 60, and from the viewpoint of slidability with the slide operation wire 40 (a, b), for example, polyether Fluorine polymer materials such as ether ketone, polysulfone (PSF), polytetrafluoroethylene (PTFE), and polyvinylidene fluoride (PVDF) can be suitably used.

  There are various methods for inserting the slide operation line 40 (a, b) into the operation line capillary 30 (a, b). The slide operation lines 40 (a, b) may be inserted from one end side of the sheath 16 in which the operation line thin tubes 30 (a, b) are embedded in advance. Alternatively, the sheath 16 may be formed by extruding the operation line tubule 30 (a, b) into which the slide operation line 40 (a, b) is inserted in advance together with the resin material of the inner layer 20.

  Specific materials for the slide operation line 40 (a, b) include, for example, polyether ether ketone, polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), polymer fiber such as PI or PTFE, SUS, Corrosion-resistant coated steel wires, metal wires such as titanium or titanium alloys can be used.

  In addition, heat resistance is calculated | required for the slide operation line 40 (a, b), such as when inserting the slide operation line 40 (a, b) with respect to the sheath 16 by which the operation line thin tube 30 (a, b) was previously embedded. If not, polyvinylidene fluoride, high-density polyethylene (HDPE), or polyester may be used in addition to the above materials.

  As shown in FIG. 1, the distal end portion 15 of the sheath 16 is provided with a ring-shaped marker 66 made of a material that does not transmit radiation such as X-rays. Specifically, a metal material such as platinum can be used for the marker 66. The marker 66 of the present embodiment is provided outside the inner layer 20 and inside the outer layer 64.

  A distal end portion (distal end portion) 41 of the slide operation line 40 (a, b) is fixed to the distal end portion 15 of the catheter 10. A mode in which the tip end portion 41 of the slide operation line 40 (a, b) is fixed to the distal end portion 15 is not particularly limited.

  For example, the tip portion 41 of the slide operation line 40 (a, b) may be fastened to the marker 66, welded to the distal end portion 15 of the sheath 16, or the marker 66 or the sheath 16 with an adhesive. The distal end portion 15 may be adhesively fixed. In the present embodiment, the tip portion 41 of the slide operation line 40 (a, b) is embedded in the resin of the reinforcing resin layer 60.

  The distal end portion 15 of the sheath 16 refers to a predetermined region on the distal end side that is inserted into the body of the subject of the sheath 16. Further, the proximal end portion 17 of the sheath 16 refers to a predetermined region on the end side operated by the operator.

  Similarly, the distal end portion 41 of the slide operation line 40 (a, b) refers to a predetermined area including the distal end of the slide operation line 40 (a, b), and the proximal end portion of the slide operation line 40 (a, b). Means a predetermined region including the base end of the slide operation line 40 (a, b).

  The catheter 10 of the present embodiment is a slide operation in which a pair of slide operation lines 40 (a, b) drawn out from the pair of operation line tubules 30 (a, b) in the vicinity of the proximal end of the sheath 16 is manually operated. A mechanism (not shown) is formed.

  Furthermore, since the reinforcing layer 50 is wound around the outer periphery of the inner layer 20 instead of a strong blade as described above, it can be easily and selectively inserted into a branched small blood vessel. it can.

  In addition, since the slide operation line 40 (a, b) is located inside the reinforcing layer 50, the slide operation line 40 (a, b) slides greatly due to free bending of the sheath, and the operability is hindered. There is nothing.

  Further, in the catheter 10 of the present embodiment, separate operation line tubules 30 (a, b) are arranged outside the inner layer 20. For this reason, the inner layer 20 and the operation wire tubules 30 (a, b) can be formed of the optimum materials for each, and the operation wire tubules 30 (a, b) can be arranged on the outer peripheral surface of the inner layer 20. Easy.

  In the catheter 10 of the present embodiment, when the first slide operation line 40a or the second slide operation line 40b is pulled, tension is applied to the distal end portion 15 of the sheath 16, and the slide operation line The distal end portion 15 bends to the side through which 40 (a, b) is inserted.

  Here, the bending of the sheath 16 means that a part or all of the sheath 16 is bent or bent. For this reason, the operator can orient | assign the distal end part 15 of the catheter 10 to a desired direction rapidly.

  In the catheter 10 of the present embodiment, the reinforcing layer 50 formed on the outer periphery of the lumen 21 is composed of a plurality of types of cross-sectional wires 51 and 52 that are wound in multiple strands. Therefore, for example, as shown in FIG. 3, a convex portion 65 corresponding to the large-diameter wire 52 is formed on the outer layer 64 positioned on the outer peripheral surface of the reinforcing layer 50, thereby rotating the entire catheter 10. Thus, it is possible to generate forward and backward driving force.

  Further, in the catheter 10 of the present embodiment, as shown in FIG. 1, since the plurality of types of wires 51 and 52 are positioned on the inner peripheral surface of the outer layer 64, the small-diameter wire 51 is easily displaced. It becomes easy to bend. Therefore, the balance between the degree of freedom of bending and the degree of reinforcement can be made appropriate.

  Furthermore, the catheter 10 of the present embodiment has a cylindrical inner layer 20 in which the lumen 21 is formed on the inner side and the reinforcing layer 50 is formed on the outer periphery, and at the proximal end side that is at least a part of the entire length. A plurality of types of wires 51 and 52 of the reinforcing layer 50 are tightly wound on the outer peripheral surface of the inner layer 20. For this reason, the proximal end side of the catheter 10 can be firmly reinforced, and insertion into the human body can be facilitated.

  Further, the small-diameter wire 51 of the reinforcing layer 50 is held in pressure contact with the outer peripheral surface of the inner layer 20 by the large-diameter wire 52. For this reason, unnecessary displacement of the small-diameter wire 51 and springback during winding can be prevented by the large-diameter wire 52.

  Further, the catheter 10 of the present embodiment has a cylindrical outer layer 64 in which the reinforcing layer 50 is formed inside, and as shown in FIG. 1, the reinforcing layer 50 is formed on the distal end side which is at least a part of the entire length. A plurality of types of wires 51 and 52 are wound on the inner peripheral surface of the outer layer 64. For this reason, since the small-diameter wire 51 can be displaced in the space formed by the large-diameter wire 52, the distal end portion of the catheter 10 can be bent well.

  As shown in FIG. 3, in order to make the small-diameter wire 51 adhere to the outer peripheral surface of the inner layer 20 together with the large-diameter wire 52 as described above, the wires 51 and 52 are connected to the outer peripheral surface of the core wire (not shown). And then heating to suppress the spring back, and the inner layer 20 may be formed on the inner surfaces of the wires 51 and 52 in which the spring back is thus suppressed.

  On the other hand, as shown in FIG. 1, in order to make the small-diameter wire 51 adhere to the inner peripheral surface of the outer layer 64 together with the large-diameter wire 52 as described above, the wires 51 and 52 are wound around the outer peripheral surface of the inner layer 20. Then, the heating temperature and time may be adjusted to spring back the small-diameter wire 51.

  The present invention is not limited to the above-described embodiment, and includes various modifications and improvements as long as the object of the present invention is achieved. For example, in the above embodiment, the operation wire tubules 30 (a, b) are illustrated as being formed of resin. However, the operation wire thin tube may be formed of a thin tube coil around which a fine metal wire or resin wire is wound (not shown).

  An operation wire tubule made of such a tubule coil has a high pressure resistance, so that it is difficult to be compressed when the reinforcing layer 50 is wound. Further, since the area of contact with the slide operation line 40 (a, b) is extremely reduced, the frictional force of the slide movement of the slide operation line 40 (a, b) can also be reduced.

  Moreover, in the said form, eight small diameter wires 51 and four large diameter wires 52 were illustrated by being multi-winded. However, the number and cross-sectional shape of such multi-strand windings can be combined in various ways.

  Further, in the above embodiment, the plurality of types of wires 51 and 52 of the reinforcing layer 50 are tightly wound on the outer peripheral surface of the inner layer 20 on the base end side which is at least a part of the entire length, and at least a part of the entire length. A plurality of types of wires 51 and 52 of the reinforcing layer 50 are illustrated as being wound on the inner peripheral surface of the outer layer 64 on the distal end side.

  However, the plurality of types of wires 51 and 52 of the reinforcing layer 50 may be tightly wound on the outer peripheral surface of the inner layer 20 in the entire length, and the plurality of types of wires 51 and 52 of the reinforcing layer 50 in the entire length may be the outer layer 64. It may be pitch-wound on the inner peripheral surface. Further, the types of the wires 51 and 52 may be different between the proximal end side and the distal end side (not shown).

  Further, in the above embodiment, the slide operation line 40 (a, b) protruding forward from the operation line capillary 30 (a, b) is embedded in the resin of the reinforcing resin layer 60 and connected to the distal end portion 15 of the catheter 10. Exemplified that However, at least a part of the distal end side of the operation wire tubule 30 (a, b) may be formed of a tubule coil (not shown).

  Such a thin tube coil has a structure in which an extremely fine metal wire or resin wire is wound to have the same diameter as the resin portion of the operation wire thin tube 30 (a, b), and is formed to have a total length of 20 to 200 mm, for example. In such a catheter (not shown), since the sheath 16 is easily bent at the portion of the thin tube coil, the flexibility of the distal end portion of the sheath 16 can be improved.

  Moreover, in the catheter 10 mentioned above, it assumed that the marker 66 was arrange | positioned on the outer side of the position where the front-end | tip part of the operation wire tubule 30 (a, b) is embed | buried under the reinforcement resin layer 60. FIG. However, the distal end portion of the operation wire tubule 30 (a, b) may be embedded in the reinforcing resin layer 60 behind the position of the marker 66 (not shown).

  Furthermore, in the said form, it illustrated that the inside of the inner layer 20 opened directly. However, a layer film such as a fluorine coat (PTFE) may be formed on the inner peripheral surface of the inner layer 20 with a layer thickness of 15 μm or the like.

  Moreover, in the said form, it has illustrated that the distal end part 15 of the sheath 16 can be deflected in two directions by having a pair of slide operation line 40 (a, b). However, it is possible to deflect the distal end portion 15 of the sheath 16 in four directions, up, down, left, and right, by making the two pairs of slide operation lines 40 (a, b) orthogonal in the axial direction. Not shown).

  Furthermore, in the said form, it illustrated that the eight small diameter wires 51 and the four large diameter wires 52 were wound in multiple strips. However, like the catheter 100 illustrated in FIGS. 4 and 5, seven small-diameter wires 51 and one large-diameter wire 52 may be wound in multiple strands.

  Needless to say, the above-described embodiment and a plurality of modifications can be combined within a range in which the contents do not conflict with each other. Further, in the above-described embodiments and modifications, the structure of each part has been specifically described, but the structure and the like can be changed in various ways within a range that satisfies the present invention.

DESCRIPTION OF SYMBOLS 10 Catheter 15 Distal end part 16 Sheath 17 Proximal end part 20 Inner layer 21 Lumen 30a Operation line thin tube 30b Operation line thin tube 40a Slide operation line 40b Slide operation line 41 Tip part 50 Reinforcement layer 51 Wire 52 Wire 60 Reinforcement resin layer 64 Outer layer 65 Convex 66 Marker

Claims (10)

A catheter having a reinforcement layer formed on the outer periphery of the lumen;
The reinforcing layer is a catheter in which a plurality of types of wires having different cross-sectional shapes orthogonal to the longitudinal direction of the wire are wound in multiple strands.   The catheter according to claim 1, wherein the plurality of types of wires have different cross-sectional areas orthogonal to the longitudinal direction.   The catheter according to claim 2, wherein the plurality of types of wires have different diameters. An inner layer in which the lumen is formed on the inner side and the reinforcing layer is formed on the outer periphery;
The catheter according to any one of claims 1 to 3, wherein a plurality of types of the wires of the reinforcing layer are wound on the outer peripheral surface of the inner layer at least at a part of the entire length. An outer layer on which the reinforcing layer is formed;
The catheter according to any one of claims 1 to 4, wherein a convex portion corresponding to the large-diameter wire is formed on the outer peripheral surface of the outer layer at least at a part of the entire length.   The catheter according to claim 4 or 5, wherein a plurality of types of the wires of the reinforcing layer are tightly wound on the outer peripheral surface of the inner layer on the base end side of the entire length.   The catheter according to any one of claims 4 to 6, wherein at least a part of the small-diameter wire of the reinforcing layer is held on the outer peripheral surface of the inner layer by the large-diameter wire. An outer layer on which the reinforcing layer is formed;
The catheter according to any one of claims 1 to 7, wherein a plurality of types of the wires of the reinforcing layer are wound on the inner peripheral surface of the outer layer over at least a part of the entire length.   The catheter according to claim 8, wherein a plurality of types of the wires of the reinforcing layer are wound on the inner peripheral surface of the outer layer on the distal end side of the entire length.   The catheter according to claim 9, wherein the large-diameter wire and the small-diameter wire are wound in close contact with each other on the inner peripheral surface of the outer layer, and the small-diameter wire is separated from the inner layer.

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