Catheter and method of manufacturing the same

Abstract

To provide a catheter and a method of manufacturing the same that can improve bonding strength in a peeling direction while securing bonding strength in a traction direction of a traction wire with respect to a movable tube.SOLUTION: A catheter 10 includes: a movable tube 30 which can move along an axial direction; an outer tube 50 having a fixing part 51 provided on a radially outer side of the movable tube 30 and fixed to an outer peripheral surface of the movable tube 30; and at least one traction wire 80 with a tip end and a base end sandwiched between the movable tube 30 and the outer tube 50, a tip end side of the traction wire 80 being positioned between the fixing part 51 and the movable tube 30. The outer tube 50 includes a non-fixing part 52 which can move away from the outer peripheral surface of the movable tube 30 in a range containing an end part on the base end side relative to the fixing part 51.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a catheter and a method for manufacturing the same. [Background technology]

[0002] In recent years, for example, in the treatment of myocardial infarction and angina pectoris, a method is used in which a stent is placed in the diseased part (stenosis) of the coronary artery to secure space within the coronary artery, and a similar method is sometimes used to improve stenosis occurring in other blood vessels, bile ducts, tracheas, esophagus, urethra, and other biological lumens. Stents are classified into balloon-expandable stents and self-expandable stents depending on their function and placement method.

[0003] A balloon-expandable stent does not have an expansion function itself, and after reaching the target site, it is expanded by a balloon and is fixed in close contact with the lumen. In contrast, a self-expandable stent has an expansion function itself, and is housed in a catheter in a pre-reduced state. After reaching the target site, the self-expandable stent is released from the catheter, expands by its own expansion force, and is fixed in close contact with the lumen. For example, Patent Document 1 describes a device in which a self-expandable stent is housed in an inner sleeve and transported to the target site, and the self-expandable stent is released from the inner sleeve by pulling with a pulling wire to expand it. The pulling wire is fixed to a tubular member at the tip to release the self-expandable stent from the inner sleeve. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2018 / 333284 Summary of the Invention [Problem to be solved by the invention]

[0005] In the invention of the above-mentioned Patent Document 1, the bonding strength of the pulling wire to the tubular member can be sufficiently ensured in the pulling direction that is assumed in advance, but it may be insufficient in a peeling direction perpendicular to the pulling direction that is not assumed.

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a catheter and a manufacturing method thereof that can improve the bonding strength in the peeling direction while ensuring the bonding strength of the pulling wire to the movable tube in the pulling direction. [Means for solving the problem]

[0007] The above object can be achieved by the invention described in (1) below. (1) A catheter according to the present invention comprises a movable tube movable along an axial direction, an outer tube arranged radially outside the movable tube and having a fixed part fixed to an outer peripheral surface of the movable tube, and at least one pulling wire having a tip and a base end and sandwiched between the movable tube and the outer tube, the tip side of the pulling wire being located between the fixed part and the movable tube, and the outer tube has a non-fixed part movable away from the outer peripheral surface of the movable tube in a range including an end part on the base side of the fixed part. Effect of the Invention

[0008] The catheter described in (1) above has a non-fixed part on the proximal end side of the fixed part that fixes the pulling wire to the movable tube, so that the movement of the fixed part in the direction in which it peels off from the movable tube is restricted by the non-fixed part, making it difficult for the fixed part to peel off from the movable tube. Therefore, this catheter can improve the joining strength in the peeling direction while ensuring the joining strength in the pulling direction of the pulling wire to the movable tube.

[0009] (2) In the catheter described in (1) above, the proximal side of the tip of the traction wire may be located between the non-fixed part and the movable tube. This allows the catheter to absorb a force in a peeling direction perpendicular to the pulling direction acting on the traction wire led out from the fixed part to the proximal side by the non-fixed part located on the proximal side of the fixed part, making it difficult for the fixed part to peel off from the movable tube. Therefore, the catheter can effectively prevent the traction wire from peeling off from the movable tube.

[0010] (3) In the catheter according to (1) or (2) above, the length of the non-fixed portion along the axial direction may be shorter than the length of the fixed portion along the axial direction, thereby enabling the catheter to firmly fix the pulling wire to the movable tube by the fixed portion.

[0011] (4) In the catheter according to any one of (1) to (3) above, the length of the non-fixed part along the axial direction of the movable tube may be 2 mm or more. This allows the catheter to effectively absorb, by the non-fixed part, a force acting on the pulling wire led out from the fixed part to the base end side in a peeling direction, and therefore effectively suppresses the pulling wire from peeling off from the movable tube.

[0012] (5) In the catheter according to any one of the above (1) to (4), the non-fixed part may be deformable so as to form a gap around the pulling wire between the movable tube and the outer tube and bend from a boundary with the fixed part as a starting point, so that the non-fixed part can approach and move away from the outer peripheral surface of the movable tube independently of the movable tube.

[0013] (6) The catheter according to any one of (1) to (5) above may have two of the traction wires, and the two traction wires may be disposed at positions opposing each other in the circumferential direction of the movable tube. This allows the catheter to evenly traction the movable tube with the two traction wires, thereby suppressing tilt of the movable tube due to traction and effectively suppressing peeling off of the traction wires from the movable tube.

[0014] (7) In the catheter according to any one of the above (1) to (6), the movable tube may have a reinforcing member formed by braiding a plurality of wires into a tubular shape, and the tip of the traction wire may be located distal to the base end of the reinforcing member. This allows the catheter to apply the traction force of the traction wire to a portion of the movable tube reinforced by the reinforcing member, thereby efficiently transmitting the traction force to the movable tube.

[0015] (8) In the catheter according to any one of (1) to (7) above, the movable tube may house an expandable deployment object in a contracted state and release the deployment object by being pulled by the pulling wire. This makes it possible to prevent the pulling wire from peeling off the movable tube when releasing the deployment object.

[0016] (9) A method for manufacturing a catheter according to the present invention includes disposing at least one pulling wire between a movable tube and an outer tube arranged radially outside the movable tube, fixing a portion of the outer tube distal to its most proximal end to the outer peripheral surface of the movable tube while sandwiching the pulling wire to form a fixed portion, and forming a non-fixed portion of the outer tube proximal to the fixed portion that can be separated from the outer peripheral surface of the movable tube.

[0017] The method for manufacturing a catheter described in (9) above can form a non-fixed portion on the base end side of the fixed portion of the outer tube fixed to the movable tube by sandwiching the pulling wire. Therefore, the method for manufacturing this catheter can manufacture a catheter that can improve strength in the peeling direction while ensuring strength in the pulling direction of the pulling wire relative to the movable tube. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a plan view showing a catheter according to an embodiment. [Diagram 2] 1A and 1B are cross-sectional views showing the tip of a catheter, in which (A) shows the state before the stent is deployed, and (B) shows the state during the stent deployment. [Diagram 3] 1A and 1B are cross-sectional views showing a catheter, in which (A) shows the vicinity of the base-end opening of the guidewire lumen, and (B) shows the vicinity of the operation section. [Figure 4] FIG. 13 is a cross-sectional view showing the second movable tube, the outer tube and the puller wire. [Diagram 5] 5A and 5B are diagrams showing the second movable tube, the outer tube, and the pulling wire, where (A) is a cross-sectional view taken along line AA in FIG. 4, (B) is a cross-sectional view taken along line BB in FIG. 4, and (C) is a cross-sectional view taken along line CC in FIG. 4. [Figure 6] 1A and 1B are cross-sectional views showing a method for manufacturing a catheter, in which (A) shows a state in which a pulling wire and an outer tube are placed on the outside of the second movable tube, and a heat shrink tube is placed on the outside of the area to be fused, and (B) shows the state in which the heat shrink tube has been heated and shrunk. [Figure 7] 5 is a cross-sectional view taken along line CC in FIG. 4, showing a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that dimensions in the drawings may be exaggerated and may differ from actual dimensions for convenience of explanation. In addition, in this specification and the drawings, components having substantially the same functions are given the same reference numerals to avoid duplicated explanation. In this specification, the side inserted into a lumen is referred to as the "distal side" and the hand side used for operation is referred to as the "base side".

[0020] The catheter 10 according to this embodiment is for placing a stent 20, which is a medical deployable object, in a narrowed or blocked area that occurs in a blood vessel, bile duct, trachea, esophagus, urethra, or other biological lumen to maintain the patency of the biological lumen. The catheter 10 is of the RX (Rapid Exchange) type, in which a guidewire 200 is inserted only at the tip side.

[0021] 1 to 3, the catheter 10 includes a stent 20, a movable tube 30 capable of accommodating the stent 20, a base end tube 60 located on the base end side of the movable tube 30, an inner tube 40 disposed inside the movable tube 30 and the base end tube 60, a base end shaft 70 disposed on the base end side of the base end tube 60, and a connection tube 71 connecting the base end tube 60 and the base end shaft 70. The catheter 10 further includes a pulling wire 80 for pulling the movable tube 30, an outer tube 50 fixed to the outer circumferential surface of the movable tube 30 by fusion, a reinforcing shaft 100 for imparting strength to the catheter 10, a reinforcing shaft fixing tube 90 for fixing the tip end of the reinforcing shaft 100 to the inner tube 40, and an operation section 110 disposed at the base end of the catheter 10.

[0022] As shown in Figs. 1, 2, 4 and 5, the movable tube 30 is movable along the axial direction. The movable tube 30 includes a first movable tube 31, a second movable tube 32 located on the base end side of the first movable tube 31, and a fixed tube 33 for fixing the first movable tube 31 and the second movable tube 32. A reduced diameter stent 20 is disposed inside the first movable tube 31. The inner peripheral surface of the first movable tube 31 is preferably coated with a low friction material so that the stent 20 can slide easily. The base end side of the first movable tube 31 is formed to have smaller outer and inner diameters than the tip side, and is disposed and fixed inside the fixed tube 33 fixed to the tip portion of the second movable tube 32.

[0023] The second movable tube 32 is fixed to the base end side of the first movable tube 31 that houses the stent 20, is movable in the axial direction together with the first movable tube 31, and is capable of entering the inside of the base end tube 60. The tip side of the second movable tube 32 is disposed and fixed inside the fixed tube 33 that is fixed to the base end part of the first movable tube 31.

[0024] The second movable tube 32 is formed of a plurality of layers, and includes an inner layer 34, a reinforcing body 35 disposed radially outward of the inner layer 34, and an outer layer 36 disposed radially outward of the inner layer 34 and the reinforcing body 35. The second movable tube 32 may be formed of a single layer.

[0025] The inner layer 34 is a tubular member that forms the inner surface of the second movable tube 32. The constituent material of the inner layer 34 is preferably a low-friction material such as a fluorine-based resin such as polytetrafluoroethylene (PTFE) or high-density polyethylene (HDPE).

[0026] The reinforcing body 35 is formed by braiding a plurality of wires into a tubular shape with gaps around the outer periphery of the inner layer 34. The reinforcing body 35 may be formed by winding wires in the same direction horizontally or by winding wires in different directions, such as clockwise or counterclockwise, and the winding pitch, lattice distance, inclination angle with respect to the circumferential direction, etc. may be changed depending on the position, and the configuration is not particularly limited.

[0027] The cross-sectional shape of the wire of the reinforcing member 35 is not particularly limited, but may be, for example, a circle, an ellipse, an oval, a square, a rectangle, or the like.

[0028] The wire used for the reinforcing member 35 may be a metal wire such as stainless steel, platinum (Pt) or tungsten (W), resin fiber, carbon fiber, glass fiber, or the like, or a combination of a plurality of these wires may be used.

[0029] The outer layer 36 is a tubular member that covers the outer periphery of the inner layer 34 and the reinforcing body 35. The outer layer 36 forms the outer peripheral surface of the second movable tube 32. The outer layer 36 is fixed to the inner layer 34 and the reinforcing body 35.

[0030] The material constituting the outer layer 36 is preferably one that can be heat-sealed to the outer tube 50 and that has both hardness and flexibility, and examples of suitable materials include thermoplastic resins such as polyamide, polyether ether ketone (PEEK), and polyimide.

[0031] As shown in Figs. 2, 4 and 5, the outer tube 50 is a member for fixing the traction wire 80 to the second movable tube 32. The outer tube 50 is disposed radially outside the outer layer 36, and is fixed to the outer peripheral surface of the outer layer 36 by fusion while sandwiching at least one (two in this embodiment) traction wire 80 between the outer tube 50 and the outer layer 36. The outer tube 50 has a fixed part 51 fixed to the outer layer 36, and a non-fixed part 52 located on the base end side of the fixed part 51 and not fixed to the outer layer 36. The fixed part 51 is formed in a cylindrical shape in a predetermined range along the axial direction of the outer tube 50. The non-fixed part 52 is formed in a cylindrical shape in a predetermined range on the base end side of the outer tube 50, continuously from the fixed part 51 to the base end side. Since the non-fixed part 52 is not fixed to the second movable tube 32, it covers the second movable tube 32, forms a gap 55 around the pulling wire 80 between the second movable tube 32 and the fixed part 51, and is deformable so as to bend starting from the boundary part 54 with the fixed part 51. Therefore, the non-fixed part 52 can move toward and away from the outer circumferential surface of the movable tube 32 in the radial direction, independent of the second movable tube 32. In Figs. 4 and 5, the gap 55 extends over the entire circumference of the outer circumferential surface of the second movable tube 32 and the inner circumferential surface of the outer tube 50, including the circumference of the pulling wire 80. However, as will be described later, there may be a gap only around the pulling wire 80. Note that the gap 55 includes a case where the outer circumferential surface of the second movable tube 32 and the inner circumferential surface of the outer tube 50 are separated by a space, as well as a case where the range in which both members are in contact but not fixed is a part or the whole of the circumferential direction. The non-fixed part 52 has a reduced diameter part 53 that is narrowed so as to be narrowed at the free end side located at the most proximal end side. With this configuration, it is possible to suppress the pulling wire 80 from peeling off the second movable tube 32 as described later. In addition, the reduced diameter part 53 can prevent the second movable tube 32 from getting caught when being pulled into the proximal tube 60. It is preferable that at least a part of the fixed part 51 overlaps so as to surround the part of the outer tube 50 where the reinforcing body 35 is disposed. In other words, the tip of the fixed part 51 is located on the tip side relative to the proximal end of the reinforcing body 35.In addition, the base end of the outer tube 50 (i.e., the base end of the non-fixed portion 52) coincides with the base end of the movable tube 30 or is located further toward the tip side than the base end of the movable tube 30. This prevents the base end of the non-fixed portion 52 from protruding toward the base end side from the base end of the movable tube 30, thereby preventing interference from other members.

[0032] The tips of the two traction wires 80 sandwiched between the outer tube 50 and the second movable tube 32 are located on the tip side of the base end of the fixed part 51. Therefore, a predetermined range on the tip side of the traction wires 80 is sandwiched between the fixed part 51 of the outer tube 50 and the second movable tube 32 and fixed to the second movable tube 32. In addition, it is preferable that the tips of the traction wires 80 are located on the tip side of the most base end of the reinforcing body 35. This allows the traction force of the traction wires 80 to act on the part of the second movable tube 32 reinforced by the reinforcing body 35, so that the traction force can be efficiently transmitted to the second movable tube 32.

[0033] The material of outer tube 50 is not particularly limited as long as it can be heat-sealed to outer layer 36, and examples of the material that can be used include thermoplastic resins such as polyamide, polyetheretherketone (PEEK), and polyimide.

[0034] The outer diameter of the second movable tube 32 is not particularly limited, but is preferably 1.71 mm to 1.76 mm, and as a specific example, is 1.75 mm. The thickness of the outer tube 50 is not particularly limited, but is preferably 0.05 mm to 0.10 mm, and as a specific example, is 0.08 mm. The axial length of the fixed portion 51 is not particularly limited, but is preferably 3.0 mm or more, and as a specific example, is 7.0 mm. The axial length of the non-fixed portion 52 is not particularly limited, but is preferably 2.0 mm or more, and as a specific example, is 2.0 mm.

[0035] 1 to 3, the proximal tube 60 is a tubular body capable of receiving the second movable tube 32 moving toward the proximal side from the distal side into the inside. The inner circumferential surface of the region on the distal side of the proximal tube 60 into which the second movable tube 32 enters may be coated with a low-friction material. This allows the proximal tube 60 to smoothly receive the second movable tube 32 inside.

[0036] 1 and 3, the connection tube 71 is a tube that connects the proximal tube 60 and the proximal shaft 70. The connection tube 71 is connected to the proximal tube 60 and the proximal shaft 70 by heat fusion or adhesion. The connection tube 71 has a through hole 73 through which the reinforcing shaft 100 and the traction wire 80 pass.

[0037] 2 and 3, the inner tube 40 is a tubular body in which a guidewire lumen 41 is formed at the distal end side of the catheter 10. The inner tube 40 includes a distal inner tube 42, a proximal inner tube 43 located on the proximal end side of the distal inner tube 42, a distal tip 44 fixed to the distal end side of the distal inner tube 42, a distal marker 45, and a proximal marker 46 (locking portion). The distal tip 44, the distal inner tube 42, and the proximal inner tube 43 are aligned in a row in the axial direction and form a common guidewire lumen 41.

[0038] At least a portion of the distal inner tube 42 is located inside the first movable tube 31, and penetrates the inside of the stent 20 disposed inside the first movable tube 31. The distal end of the distal inner tube 42 is located on the distal side of the first movable tube 31, and the proximal end of the distal inner tube 42 is located inside the proximal tube 60. A distal tip 44 is fixed to the distal side of the distal inner tube 42.

[0039] The distal tip 44 is a flexible member that constitutes the distal end of the inner tube 40. The guidewire lumen 41 opens at a distal opening 47 formed at the distal end of the distal tip 44. The distal tip 44 may be formed integrally with the distal inner tube 42. The base end surface of the distal tip 44 contacts or is adjacent to the distal end surface of the first movable tube 31 that houses the stent 20.

[0040] The proximal inner tube 43 is located on the proximal side of the distal inner tube 42, and is arranged coaxially with the distal inner tube 42. The proximal side of the proximal inner tube 43 is connected to the connecting tube 71. The guidewire lumen 41 of the proximal inner tube 43 communicates with a proximal opening 72 provided in the connecting tube 71. A gap is formed between the distal end surface of the proximal inner tube 43 and the proximal end surface of the distal inner tube 42. Therefore, the priming liquid flowing in from the guidewire lumen 41 can flow through the gap between the distal inner tube 42 and the proximal inner tube 43.

[0041] 3, the reinforcing shaft fixing tubes 90 are tubular bodies that cover the inner tube 40 and the reinforcing shaft 100 together in the internal space 39 of the base end tube 60. One of the reinforcing shaft fixing tubes 90 covers and fixes the base end inner tube 43 and the reinforcing shaft 100 together, and the other reinforcing shaft fixing tube 90 covers and fixes the tip end inner tube 42 and the reinforcing shaft 100 together.

[0042] As shown in FIG. 2, the base end marker 46 is a ring-shaped member fixed to the outer surface of the distal inner tube 42, and has radiopaque properties. The base end marker 46 is used to grasp the position of the base end of the stent 20 under X-ray fluoroscopy. The base end marker 46 also serves as a locking portion that restricts movement of the stent 20 toward the base end side. The outer diameter of the base end marker 46 is large enough to abut against the base end of the stent 20 housed in the first movable tube 31. When the movable tube 30 moves toward the base end side, the base end of the stent 20 abuts against the base end marker 46, and the axial position of the stent 20 is maintained, resulting in the stent 20 being released from the movable tube 30.

[0043] The tip marker 45 is a ring-shaped member fixed to the outer surface of the tip inner tube 42, and has X-ray contrast properties. The tip marker 45 is used to grasp the position of the tip of the stent 20 under X-ray fluoroscopy. The outer surface on the tip side of the tip marker 45 contacts or is close to the inner surface of the first movable tube 31.

[0044] 3, the reinforced shaft 100 is a metal member for imparting rigidity to the catheter 10. The reinforced shaft 100 is one or more pieces of wire (one piece in this embodiment).

[0045] The base end side of the reinforcing shaft 100 is fixed to the operating section 110 inside the operating section 110. The reinforcing shaft 100 is located inside the proximal shaft 70, the through hole 73 of the connection tube 71, and the proximal tube 60. The tip side of the reinforcing shaft 100 is fixed to the outer surfaces of the distal inner tube 42 and the proximal inner tube 43 by the reinforcing shaft fixing tube 90.

[0046] As shown in Figs. 2 to 5, the pulling wire 80 is a wire for pulling the movable tube 30 toward the base end side to release the stent 20 from the movable tube 30. One or more pulling wires 80 (two in this embodiment) are provided. In this embodiment, the two pulling wires 80 are arranged at opposing positions (positions shifted by 180 degrees) on the outer circumferential surface of the base end of the second movable tube 32, and are fixed by being sandwiched between the outer tube 50 and the second movable tube 32. The tip end of each pulling wire 80 sandwiched between the outer tube 50 and the second movable tube 32 is preferably formed into a flat plate shape by press processing or the like. Alternatively, the tip end of the pulling wire 80 may be formed into a curved plate shape so as to have a curved surface that can be in close contact with the curved shape of the outer circumferential surface of the second movable tube 32. This can increase the contact area of ​​the pulling wire 80 with the outer tube 50 and the second movable tube 32. Therefore, the pulling wire 80 can stably transmit the pulling force, improve the resistance to peeling from the outer tube 50 and the second movable tube 32, and suppress an increase in the outer diameter of the catheter 10. The multiple pulling wires 80 may be independent of each other, or may be joined to have a common base end. The base end side of the pulling wire 80 is fixed to the operating part 112 of the operation part 110 described later. The pulling wire 80 is arranged in the inner cavity of the base end shaft 70, the through hole 73 of the connection tube 71, and the internal space 39 of the base end tube 60.

[0047] A wire or a plurality of twisted wires can be suitably used as the pulling wire 80. The thickness of the pulling wire 80 is not particularly limited, but is, for example, 0.15 mm to 0.30 mm.

[0048] The material of the pulling wire 80 is not particularly limited, but may be, for example, a stainless steel wire (preferably, high-tensile stainless steel for springs), a piano wire (preferably, a piano wire plated with nickel or chrome), or a wire material formed of various metals such as a superelastic alloy wire, a Ni-Ti alloy, a Cu-Zn alloy, a Ni-Al alloy, tungsten, a tungsten alloy, titanium, a titanium alloy, a cobalt alloy, or tantalum, or a relatively high-rigidity polymer material such as polyamide, polyimide, ultra-high molecular weight polyethylene, polypropylene, or a fluororesin, or an appropriate combination of these. In addition, the surface of the pulling wire 80 may be coated with a low-friction resin that increases the lubricity. As the low-friction resin, a fluororesin, nylon 66, polyether ether ketone, high-density polyethylene, or the like may be preferably applied.

[0049] The stent 20 is made of a superelastic alloy and formed into a generally cylindrical shape, and is housed in the first movable tube 31 in a state compressed toward the central axis, as shown in Fig. 2. When the stent 20 is pushed out from the opening on the distal end side of the first movable tube 31, the stress load is removed, the stent 20 expands, and the stent 20 restores to its shape before compression. The shape of the stent 20 is not limited as long as it is a so-called self-expanding stent 20. As an example, the stent 20 may be formed into a generally cylindrical shape by connecting a plurality of annular portions formed into an annular shape while bending.

[0050] As shown in Figures 1 and 3, the operating unit 110 includes an operating main body 111, an operating part 112 that is rotatable relative to the operating main body 111, a kink-resistant protector 113, a fixing part 114 that fixes the reinforcing shaft 100 and the base end of the base shaft 70 to the operating main body 111, and a valve body 116.

[0051] The operation body 111 is a portion that is held by the operator. The operating unit 112 can rotate with respect to the operation body 111 by the operator's operation to wind up the base end of the traction wire 80 and tow the traction wire 80. The valve body 116 is for introducing the traction wire 80 extending from the inside of the base end shaft 70 to the base end side into the operation body 111 while allowing the traction wire 80 to move in the axial direction and maintaining a liquid-tight state. The valve body 116 has a hole or slit through which the traction wire 80 slidably passes. The kink-resistant protector 113 partially protrudes from the operation body 111 to the tip side while covering the base end side of the base end shaft 70. The kink-resistant protector 113 suppresses kinking on the base end side of the base end shaft 70.

[0052] When manufacturing the catheter 10 according to this embodiment, the manufacturer fixes the pulling wire 80 to the second movable tube 32. As an example of fixing the pulling wire 80 to the second movable tube 32, the manufacturer covers the outside of the second movable tube 32 with the outer tube 50, as shown in FIG. 6(A), and arranges the tip end of each pulling wire 80 at a predetermined position between the second movable tube 32 and the outer tube 50. Next, the manufacturer covers a predetermined range on the tip end side of the outer tube 50 with the heat shrink tube 130, leaving a predetermined range on the base end side of the outer tube 50, and heats this range with a heating means such as a heater. As a result, the heat shrink tube 130 shrinks, and the heated outer tube 50 is brought into close contact with the outer peripheral surface of the pulling wire 80 and the second movable tube 32. As a result, the outer tube 50 is heat-sealed to the outer peripheral surface of the second movable tube 32, as shown in FIG. 6(B). After this, the heat shrink tube 130 is removed. As a result, a fixed portion 51 and a non-fixed portion 52 are formed on the outer tube 50, and the pulling wire 80 is firmly fixed between the fixed portion 51 and the second movable tube 32.

[0053] Next, a method of using the catheter 10 according to this embodiment will be described.

[0054] The surgeon percutaneously inserts a guidewire 200 (see FIG. 1) into a blood vessel, and inserts the proximal end of the guidewire 200 from the distal opening 47 into the guidewire lumen 41. The guidewire 200 is led out from the proximal opening 72.

[0055] Next, the surgeon inserts the catheter 10 into the blood vessel along the guide wire 200, and causes it to reach the target site. Next, the surgeon rotates the operating unit 112, as shown in Fig. 1 and 3(B). As a result, the pulling wire 80 is wound around the operating unit 112, and the pulling wire 80 moves toward the base end side.

[0056] When the pulling wire 80 moves toward the base end side, as shown in FIG. 2(B), since the tip side of the pulling wire 80 is fixed to the movable tube 30, the movable tube 30 moves toward the base end side. At this time, the second movable tube 32 of the movable tube 30 can enter the inside of the base end tube 60. Since the base end surface of the stent 20 abuts against and is locked to the tip end surface of the base end marker 46 of the inner tube 40, when viewed from the movable tube 30, the stent 20 moves toward the tip side on the inner surface of the movable tube 30. As a result, the stent 20 is gradually released from the opening on the tip side of the first movable tube 31. By this release, the stent 20 expands by its own elastic force to expand the stenosed portion and is placed in the stenosed portion.

[0057] Incidentally, since the pulling wire 80 is fixed by being sandwiched between the fixed part 51 of the outer tube 50 and the second movable tube 32, the joining strength of the pulling wire 80 to the second movable tube 32 in the pulling direction is high. Therefore, the pulling wire 80 can stably pull the second movable tube 32 in the pulling direction (proximal end direction) without coming off in the axial direction with respect to the second movable tube 32. In addition, since the outer tube 50 has the non-fixed part 52 on the proximal end side of the fixed part 51, the pulling wire 80 led out from the fixed part 51 to the proximal end side comes into contact with the non-fixed part 52 when it receives a force in a peeling direction (a direction moving away from the outer circumferential surface of the second movable tube 32 radially outward) perpendicular to the pulling direction. At this time, the non-fixed part 52 flexibly deforms and absorbs the force that moves the pulling wire 80 in the peeling direction. Therefore, the base end of the fixed part 51 covering the pulling wire 80 hardly receives a force in the peeling direction from the pulling wire 80, and is difficult to peel off from the second movable tube 32. Therefore, the fixed part 51 of the outer tube 50 located on the tip side of the non-fixed part 52 is difficult to receive a force in the peeling direction from the pulling wire 80, and is difficult to peel off from the second movable tube 32, compared to a case where there is no non-fixed part 52 on the base end side. Therefore, peeling off of the pulling wire 80 from the second movable tube 32 can be suppressed. Furthermore, when the non-fixed part 52 has the reduced diameter part 53, the outer tube 50 more effectively absorbs the force that moves the pulling wire 80 in the peeling direction, and can further suppress peeling off of the pulling wire 80 from the second movable tube 32.

[0058] As described above, the catheter 10 according to the present embodiment includes the movable tube 30 movable along the axial direction, the outer tube 50 having the fixed part 51 disposed radially outside the movable tube 30 and fixed to the outer circumferential surface of the movable tube 30, and at least one pulling wire 80 having a tip and a base end and sandwiched between the movable tube 30 and the outer tube 50, the tip side of the pulling wire 80 being located between the fixed part 51 and the movable tube 30, and the outer tube 50 has a non-fixed part 52 that can be separated from the outer circumferential surface of the movable tube 30 in a range including an end part on the base end side of the fixed part 51. As a result, the catheter 10 has the non-fixed part 52 on the base end side of the fixed part 51 that fixes the pulling wire 80 to the movable tube 30, and therefore the movement of the fixed part 51 in the direction of peeling off from the movable tube 30 is restricted by the non-fixed part 52, and the fixed part 51 is less likely to peel off from the movable tube 30. Therefore, the catheter 10 can improve the bonding strength in the peeling direction while ensuring the bonding strength of the pulling wire 80 to the movable tube 30 in the pulling direction.

[0059] The proximal side of the tip of the pulling wire 80 is located between the non-fixed part 51 and the movable tube 30. As a result, in the catheter 10, the force in the peeling direction perpendicular to the pulling direction acting on the pulling wire 80 led out from the fixed part 51 to the proximal side can be absorbed by the non-fixed part 52 located on the proximal side of the fixed part 51, so that the fixed part 51 is unlikely to peel off from the movable tube 30. Therefore, the catheter 10 can effectively suppress the pulling wire 80 from peeling off from the movable tube 30.

[0060] The length along the axial direction of the non-fixed portion 52 is shorter than the length along the axial direction of the fixed portion 51. This allows the catheter 10 to firmly fix the pulling wire 80 to the movable tube 30 by the fixed portion 51.

[0061] Moreover, the length of the non-fixed part 52 along the axial direction of the movable tube 30 is 2 mm or more. As a result, in the present catheter 10, the force acting in the peeling direction on the pulling wire 80 led out from the fixed part 51 to the base end side can be effectively absorbed by the non-fixed part 52, so that the pulling wire 80 can be effectively prevented from peeling off from the movable tube 30.

[0062] The non-fixed portion 52 forms a gap around the pulling wire 80 between the movable tube 30 and the outer tube 50, and is deformable so as to bend starting from a boundary portion 54 with the fixed portion 51. This allows the non-fixed portion 52 to approach and move away from the outer circumferential surface of the movable tube 30 independently of the movable tube 30.

[0063] Moreover, the catheter 10 has two pulling wires 80, and the two pulling wires 80 are arranged at positions opposing each other in the circumferential direction of the movable tube 30. As a result, the catheter 10 can evenly pull the movable tube 30 with the two pulling wires 80, thereby suppressing tilt of the movable tube 30 due to pulling, and effectively suppressing the pulling wires 80 from peeling off the movable tube 30.

[0064] In addition, the movable tube 30 has a reinforcing member 35 formed by braiding a plurality of wires into a tubular shape, and the tip of the traction wire 80 is located on the tip side of the base end of the reinforcing member 35. As a result, the catheter 10 can apply the traction force of the traction wire 80 to the portion of the movable tube 30 reinforced by the reinforcing member 35, and therefore can efficiently transmit the traction force to the movable tube 30.

[0065] The movable tube 30 may also accommodate an expandable deployment object (stent 20) in a contracted state and release the deployment object by being pulled by the pulling wire 80. This makes it possible for the catheter 10 to prevent the pulling wire 80 from peeling off from the movable tube 30 when releasing the deployment object. The deployment object does not have to be the stent 20.

[0066] Moreover, in the manufacturing method of the catheter 10 according to the present embodiment, at least one pulling wire 80 is disposed between the movable tube 30 and the outer tube 50 disposed radially outward of the movable tube 30, and the distal end side of the outer tube 50 is fixed to the outer peripheral surface of the movable tube 30 while sandwiching the pulling wire 80 to form a fixed part 51, while forming a non-fixed part 52 that can be separated from the outer peripheral surface of the movable tube 30 on the proximal side of the fixed part 51 of the outer tube 50. In this way, the manufacturing method of the present catheter 10 can form the non-fixed part 52 on the proximal side of the fixed part 51 of the outer tube 50 fixed to the movable tube 30 while sandwiching the pulling wire 80. Therefore, the manufacturing method of the present catheter 10 can manufacture a catheter 10 that can improve the joining strength in the peeling direction while ensuring the joining strength in the pulling direction of the pulling wire 80 to the movable tube 30.

[0067] The present invention is not limited to the above-described embodiment, and various modifications can be made by those skilled in the art within the technical concept of the present invention. For example, the traction wire 80 may be fixed to the first movable tube 31 or the fixed tube 33, instead of the second movable tube 32 of the movable tube 30. In addition, the movable tube 30 is a tube that combines the first movable tube 31 and the second movable tube 32, which are different members, in this embodiment, but it may be a single member (tube). In addition, the present invention may be applied to catheters other than the catheter 10 that delivers the stent 20. Therefore, the deployed object does not have to be the stent 20.

[0068] Also, as in the modified example shown in FIG. 7, at the axial position where the non-fixed portion 52 is formed on the outer tube 50, the non-fixed portion 52 may be formed only around at least the pulling wire 80. Therefore, the outer tube 50 may have the fixed portion 51 other than the periphery of the pulling wire 80 where the non-fixed portion 52 is formed. The peeling direction of the pulling wire 80 is usually a direction away from the movable tube 30 substantially perpendicularly, and the pulling wire 80 does not often move in the circumferential direction of the movable tube 30. Therefore, even in the structure of the modified example shown in FIG. 7, if at least the outer tube 50 around the pulling wire 80 is the non-fixed portion 52, the force that moves in the peeling direction of the pulling wire 80 can be absorbed by the non-fixed portion 52. [Explanation of symbols]

[0069] 10 Catheter 20 Stent (deployment) 30 Movable Tube 32 Second movable tube 34 Inner layer 35 Reinforcement 36 Outer layer 50 Outer tube 51 Fixed part 52 Non-fixed part 54 Boundary 55 Gap 80 Towing Wire

Claims

1. A movable tube that is movable along an axial direction; an outer tube including a fixing portion disposed radially outward of the movable tube and fixed to an outer peripheral surface of the movable tube; At least one puller wire having a distal end and a proximal end and sandwiched between the movable tube and the outer tube, the distal end side of the puller wire being positioned between the fixed portion and the movable tube; A catheter characterized in that the outer tube has a non-fixed portion that is separable from the outer peripheral surface of the movable tube in a range including the end portion on the base end side of the fixed portion.

2. The catheter according to claim 1 , wherein a proximal side of the tip of the puller wire is located between the non-fixed portion and the movable tube.

3. The catheter according to claim 1 or 2, wherein a length along the axial direction of the non-fixed portion is shorter than a length along the axial direction of the fixed portion.

4. 4. The catheter according to claim 3, wherein a length of the non-fixed portion along the axial direction of the movable tube is 2 mm or more.

5. The catheter according to claim 1 or 2, wherein the non-fixed portion forms a gap around the puller wire between the movable tube and the outer tube, and is deformable so as to bend from a boundary with the fixed portion as a starting point.

6. 3. The catheter according to claim 1, further comprising two puller wires, the two puller wires being disposed at opposing positions in the circumferential direction of the movable tube.

7. The movable tube has a reinforcing member formed by braiding a plurality of wires into a tubular shape, 3. The catheter according to claim 1, wherein the tip of the pulling wire is located distal to the base end of the reinforcing member.

8. 3. The catheter according to claim 1, wherein the movable tube accommodates an expandable deployment object in a contracted state, and the deployment object can be released by being pulled by the pull wire.

9. At least one pull wire is disposed between the movable tube and an outer tube disposed radially outward of the movable tube; A method for manufacturing a catheter, characterized in that a tip side of the outer tube rather than the base end is fixed to the outer peripheral surface of the movable tube while sandwiching the pulling wire to form a fixed portion, and a non-fixed portion that can be separated from the outer peripheral surface of the movable tube is formed on the base end side of the fixed portion of the outer tube.

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