Catheter and manufacturing method therefor

Abstract

Provided are a catheter capable of suppressing generation of foreign matter from a joint section that joins a traction wire to a tubular member, and capable of preventing the joint section from interfering with other members, and a method for manufacturing the catheter.　A catheter (10) comprises: a movable tube (31) that is movable along the longitudinal direction; a wire fixing tube (90) that is disposed on the radial outer side of the proximal end of the movable tube (31) and extends beyond the movable tube on the proximal end side (31); at least one traction wire (80) that has a distal end and a proximal end and is sandwiched between the movable tube (31) and the wire fixing tube (90); and a first joint section (91) that is disposed between the outer peripheral surface of the movable tube (31) and the inner peripheral surface of the wire fixing tube (90) and joins the traction wire (80) to the movable tube (31) and the wire fixing tube (90). At least a portion of the proximal end of the first joint section (91) in a region sandwiched between at least the traction wire (80) and the wire fixing tube (90) in the longitudinal direction of the movable tube (31) is located on a reference position (P) where the proximal end of the movable tube (31) is located or farther to the distal end side than the reference position (P).

Description

Catheter and method for manufacturing the same

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

[0002] In recent years, for example, in the treatment of myocardial infarction and angina pectoris, a method of placing a stent in a diseased portion (stenosis) of the coronary artery to secure a space in the coronary artery has been carried out, and the same method may be carried out for improving stenosis occurring in other blood vessels, bile ducts, tracheas, esophaguses, urethras, and other biological lumens. Stents are classified into balloon-expandable stents and self-expandable stents according to their functions and placement methods.

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

[0004] U.S. Patent Application Publication No. 2018 / 333284

[0005] In the invention of Patent Document 1 described above, when joining the traction wire to the tubular member, there is a possibility that the adhesive may reach an unintended position along the traction wire and cure. A joint cured at an undesirable position may have an undesirable effect on the living body if it falls off, and even if it does not fall off, it may interfere with other members, making it difficult to assemble the catheter or preventing the catheter from operating.

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a catheter and a method for manufacturing the same that can suppress the generation of foreign matter from the joint where the traction wire is joined to a tubular member, and can suppress interference of the joint with other members.

[0007] The above objective is achieved by the invention described in (1) below. (1) The catheter according to the present invention comprises: a movable tube that can move along the longitudinal axis; a wire fixing tube disposed radially outside the proximal end of the movable tube and extending further towards the proximal end than the movable tube; at least one traction wire having a tip and a proximal end and sandwiched between the movable tube and the wire fixing tube; and a joint disposed between the outer circumferential surface of the movable tube and the inner circumferential surface of the wire fixing tube for joining the traction wire to the movable tube and the wire fixing tube, wherein at least a portion of the proximal end of the joint in the region sandwiched between the traction wire and the wire fixing tube in the longitudinal axis direction of the movable tube is located on or towards the tip of the reference position where the proximal end of the movable tube is located.

[0008] In the catheter described in (1) above, the joint that connects the traction wire to the movable tube does not protrude from the proximal end of the movable tube, thereby suppressing the generation of foreign matter due to detachment from the joint and suppressing interference of the joint with other components.

[0009] (2) The catheter described in (1) above has a proximal movable tube that is positioned on the proximal side of the movable tube which is movable along the longitudinal axis and is movable along the longitudinal axis together with the movable tube, the proximal end of the wire fixing tube may be positioned radially outward of the proximal movable tube, and the traction wire may be positioned radially inward of the proximal movable tube. Since the joint does not protrude from the proximal end of the movable tube toward the proximal end, it is possible to prevent it from coming into contact with the proximal movable tube and falling off, interfering with the proximal movable tube and making it difficult to assemble the catheter, or hindering the operation of the catheter.

[0010] (3) The catheter described in (1) or (2) above may have a wire tip fixing tube positioned on the distal side of the wire fixing tube and radially outward of the movable tube, which sandwiches the traction wire between itself and the movable tube and fixes the traction wire to the movable tube. In this way, the catheter can firmly fix the movable tube to the traction wire because the traction wire is connected to the movable tube by the wire tip fixing tube in addition to the wire fixing tube.

[0011] (4) The catheter described in any one of (1) to (3) above has two traction wires, and the two traction wires may be positioned opposite each other in the circumferential direction of the movable tube. This prevents the joint between each traction wire and the wire fixing tube from protruding from the proximal end to the proximal end of the movable tube.

[0012] (5) In the catheter described in any one of (1) to (4) above, the movable tube may house an expandable deployable in a contracted state and release the deployable by being pulled by the traction wire. In this case, since the traction wire is firmly fixed to the movable tube by the wire fixing tube, it is possible to prevent the traction wire from detaching from the movable tube when releasing the deployable. In addition, since the joint does not protrude from the proximal end of the movable tube toward the proximal end, it is possible to prevent it from interfering with the operation of releasing the stent.

[0013] (6) A method for manufacturing a catheter according to the present invention is a method for manufacturing a catheter having a movable tube that is movable along the longitudinal axis and a traction wire fixed to the outer surface of the movable tube, comprising the steps of: arranging a wire fixing tube so as to cover the radially outer side of the proximal end of the movable tube and to extend further toward the proximal end than the movable tube, and arranging the traction wire between the outer surface of the movable tube and the inner surface of the wire fixing tube; inserting a cylindrical jig between the wire fixing tube and the traction wire from the proximal end side, and tilting the portion of the traction wire extending from the movable tube toward the proximal end inward with respect to the longitudinal axis of the movable tube; supplying an adhesive to the gap between the movable tube and the wire fixing tube from the tip side of the wire fixing tube; curing the adhesive to form a joint for joining the traction wire to the movable tube and the wire fixing tube; and pulling out the jig from between the wire fixing tube and the traction wire.

[0014] In the catheter manufacturing method described in (6) above, when the portion of the traction wire extending from the movable tube toward the proximal end is tilted inward with respect to the long axis of the movable tube, the portion of the traction wire extending from the movable tube toward the proximal end separates from the wire fixing tube. In this state, adhesive is supplied to the gap between the movable tube and the wire fixing tube, so the formed movable tube is less likely to protrude from the proximal end toward the proximal end. For this reason, this manufacturing method can suppress the generation of foreign matter from the joint and can also suppress interference of the joint with other components.

[0015] This is a plan view showing a catheter according to an embodiment. This is a cross-sectional view showing the tip of the catheter, where (A) is the state before stent deployment and (B) is the state during stent deployment. This is a cross-sectional view showing the catheter, where (A) is the vicinity of the proximal end opening of the guidewire lumen and (B) is the vicinity of the operating section. This is a cross-sectional view along the line A-A in Figure 2(A). This is a schematic plan view showing the manufacturing method of the catheter, where (A) is the state in which the tip of the traction wire is fixed to the outer surface of the proximal end movable tube by the wire tip fixing tube, (B) is the state in which the traction wire is fixed to the outer surface of the proximal end of the proximal end movable tube by the wire fixing tube and a jig is inserted between the wire fixing tube and the traction wire, (C) is the state in which adhesive is supplied to the gap between the proximal end movable tube and the wire fixing tube, and (D) is the state in which the jig has been withdrawn. This is a cross-sectional view showing the state in which adhesive is supplied from the tip side to the gap between the proximal end movable tube and the wire fixing tube. This is a photograph showing Test Example 1. This is a photograph showing Test Example 5. This is a photograph showing Test Example 2.

[0016] Embodiments of the present invention will be described below with reference to the drawings. Note that the dimensions in the drawings may be exaggerated for illustrative purposes and may differ from the actual dimensions. In addition, in this specification and drawings, components having substantially the same function are denoted by the same reference numerals to avoid redundant explanations. In this specification, the side inserted into the lumen will be referred to as the "tip side," and the side manipulated by the operator will be referred to as the "proximal side."

[0017] The catheter 10 according to this embodiment is for maintaining the patency of a biological lumen by placing a stent 20, which is a medical device, into a narrowed or blocked area in a blood vessel, bile duct, trachea, esophagus, urethra, or other biological lumen. The catheter 10 is an RX type (Rapid Exchange type) in which a guidewire 200 is inserted only at the tip.

[0018] As shown in Figures 1 to 3, the catheter 10 comprises a stent 20, a stent housing tube 30 capable of housing the stent 20, a proximal tube 60 located on the proximal end side of the stent housing tube 30, an inner tube 40 positioned inside the stent housing tube 30 and the proximal tube 60, a proximal shaft 70 positioned on the proximal end side of the proximal tube 60, a connecting tube 71 connecting the proximal tube 60 and the proximal shaft 70, a reinforcing shaft 100 that provides strength to the catheter 10, a reinforcing shaft fixing tube 120 that fixes the tip of the reinforcing shaft 100 to the inner tube 40, and an operating part 110 positioned at the proximal end of the catheter 10. The catheter 10 further includes a traction wire 80 for pulling the stent housing tube 30, a wire tip fixing tube 50 for fixing the tip of the traction wire 80 to the outer circumferential surface of the stent housing tube 30, a tip joint 51 for joining the wire tip fixing tube 50 to the stent housing tube 30, a wire fixing tube 90 for fixing the traction wire 80 to the outer circumferential surface of the stent housing tube 30 on the proximal end side of the wire tip fixing tube 50, and joints 91 and 92 for fixing the wire fixing tube 90 to the stent housing tube 30.

[0019] As shown in Figures 1 to 3, the stent housing tube 30 is movable along its long axis. The stent housing tube 30 comprises a movable tube 31 and a proximal movable tube 32 located on the proximal end side of the movable tube 31. A reduced-diameter stent 20 is placed inside the movable tube 31. Preferably, the inner circumferential surface of the movable tube 31 is covered with a low-friction material to allow the stent 20 to slide easily. The movable tube 31 has a reduced-diameter portion 33 at its proximal end, which has a smaller outer and inner diameter than the tip portion, and to which the traction wire 80 is fixed. The proximal end of the movable tube 31 does not necessarily have to be reduced in diameter.

[0020] The proximal movable tube 32 is positioned on the proximal end side of the movable tube 31 that houses the stent 20, and is movable in the longitudinal direction together with the movable tube 31, and is a tubular body that can enter inside the proximal tube 60.

[0021] The constituent materials of the movable tube 31 and the proximal end movable tube 32 are not particularly limited, and thermoplastic resins such as polyamide, polyetheretherketone (PEEK), and polyimide can be used.

[0022] The wire tip fixing tube 50 is a tubular body for fixing the towing wire 80 to the movable tube 31. The wire tip fixing tube 50 is positioned radially outside the reduced diameter portion 33 of the movable tube 31, and sandwiches the tip of the towing wire 80 between it and the outer surface of the reduced diameter portion 33. Adhesive is filled between the wire tip fixing tube 50 and the reduced diameter portion 33 to form a tip joint portion 51.

[0023] The wire fixing tube 90 is a tubular body that fixes the traction wire 80 to the movable tube 31 and connects the movable tube 31 to the base end movable tube 32. The wire fixing tube 90 is positioned radially outward from the base end of the reduced diameter portion 33 of the movable tube 31 and extends further towards the base end than the movable tube 31. The tip of the wire fixing tube 90 sandwiches the traction wire 80 between itself and the outer circumferential surface of the reduced diameter portion 33. Furthermore, the base end of the wire fixing tube 90 is in close contact with the outer circumferential surface of the tip of the base end movable tube 32. Adhesive is filled between the wire fixing tube 90 and the reduced diameter portion 33 to form a first joint portion 91 (joint portion). Adhesive is also filled between the wire fixing tube 90 and the base end movable tube 32 to form a second joint portion 92. In the longitudinal direction, the base end of the first joint portion 91 is located at a position that coincides with the reference position P, which is the position of the base end of the movable tube 31, or at a position further towards the tip than the reference position P. In other words, the first joint portion 91 does not protrude beyond the movable tube 31 in the direction X towards the base end. At least in the range sandwiched between the wire fixing tube 90 and the traction wire 80, the base end of the first joint portion 91 is located at a position that coincides with the reference position P, which is the position of the base end of the movable tube 31, or at a position that is closer to the tip than the reference position P. In other words, in the range not sandwiched between the wire fixing tube 90 and the traction wire 80, it is preferable that the base end of the first joint portion 91 is located at a position that coincides with the reference position P, which is the position of the base end of the movable tube 31, or at a position that is closer to the tip than the reference position P, but it may also be located closer to the base end than the reference position P. In the range not sandwiched between the wire fixing tube 90 and the traction wire 80, the amount by which the first joint portion 91 protrudes beyond the movable tube 31 in the direction X towards the base end is limited compared to the case where the adhesive flows through the gap between the wire fixing tube 90 and the traction wire 80, as will be described later. The adhesive used to form the tip joint 51, the first joint 91, and the second joint 92 is, for example, Henkel's product "LOCTITE AA3311". The viscosity of the adhesive is, for example, 200 to 400 mPa·s.

[0024] The constituent materials of the wire tip fixing tube 50 and the wire fixing tube 90 are not particularly limited, and thermoplastic resins such as polyamide, polyetheretherketone (PEEK), and polyimide can be used.

[0025] The outer diameters of the movable tube 31 and the base end movable tube 32 are not particularly limited, but are preferably 1.71 mm to 1.76 mm, and one specific example is 1.75 mm. The thickness of the wire tip fixing tube 50 and the wire fixing tube 90 is not particularly limited, but is preferably 0.05 mm to 0.10 mm, and one specific example is 0.08 mm.

[0026] As shown in Figures 1 to 3, the base tube 60 is a tubular body that can receive the base-side movable tube 32, which moves in the base-end direction X, into its interior from the tip side. The inner circumferential surface of the area on the tip side of the base tube 60 into which the base-side movable tube 32 enters may be covered with a low-friction material. This allows the base tube 60 to smoothly receive the base-side movable tube 32 into its interior.

[0027] As shown in Figures 1 and 3, the connecting tube 71 is a tubular body that connects the base tube 60 and the base shaft 70. The connecting tube 71 is connected to the base tube 60 and the base shaft 70 by heat fusion or adhesive. The connecting tube 71 has through holes 73 through which the reinforcing shaft 100 and the traction wire 80 pass.

[0028] As shown in Figures 2-3, the inner tube 40 is a tubular body in which a guidewire lumen 41 is formed at the tip of the catheter 10. The inner tube 40 comprises a tip inner tube 42, a proximal inner tube 43 located at the proximal end of the tip inner tube 42, a tip tip 44 fixed to the tip of the tip inner tube 42, a tip marker 45, and a proximal marker 46 (locking portion). The tip tip 44, tip inner tube 42, and proximal inner tube 43 are aligned in a line along their long axis, forming a common guidewire lumen 41.

[0029] The tip inner tube 42 is located at least partially inside the movable tube 31 and penetrates the inside of the stent 20, which is positioned inside the movable tube 31. The tip of the tip inner tube 42 is located further forward than the movable tube 31, and the base end of the tip inner tube 42 is located inside the base tube 60. A tip 44 is fixed to the tip side of the tip inner tube 42.

[0030] The tip 44 is a flexible component that constitutes the tip of the inner tube 40. The guide wire lumen 41 opens at the tip opening 47 formed at the tip of the tip 44. The tip 44 may be formed integrally with the tip inner tube 42. The base end surface of the tip 44 is in contact with or close to the tip surface of the movable tube 31 that houses the stent 20.

[0031] The base inner tube 43 is located on the base end side of the tip inner tube 42 and is coaxial with the tip inner tube 42. The base inner tube 43 communicates with the tip inner tube 42. The base end side of the base inner tube 43 is connected to the connecting tube 71. The guide wire lumen 41 of the base inner tube 43 communicates with a base end opening 72 provided in the connecting tube 71. A side hole 48 is formed between the tip surface of the base inner tube 43 and the base end surface of the tip inner tube 42. Therefore, priming fluid flowing in from the guide wire lumen 41 can flow through the side hole 48 between the tip inner tube 42 and the base inner tube 43.

[0032] As shown in Figure 3, the reinforcing shaft fixing tube 120 is a tubular body that covers the inner tube 40 and the reinforcing shaft 100 together within the internal space 61 of the base tube 60. One of the reinforcing shaft fixing tubes 120 covers and fixes the base inner tube 43 and the reinforcing shaft 100 together, while the other reinforcing shaft fixing tube 120 covers and fixes the tip inner tube 42 and the reinforcing shaft 100 together.

[0033] As shown in Figure 2, the proximal marker 46 is a ring-shaped member fixed to the outer surface of the tip inner tube 42 and is radiopaque. The proximal marker 46 is used to determine the position of the proximal end of the stent 20 under radiofluoroscopy. The proximal marker 46 also serves as a locking mechanism that restricts the movement of the stent 20 in the proximal direction X. The outer diameter of the proximal marker 46 is such that it can contact the proximal end of the stent 20 housed in the movable tube 31. When the stent housing tube 30 moves in the proximal direction X, the proximal end of the stent 20 contacts the proximal marker 46, maintaining the position of the stent 20 in the longitudinal axis direction, and as a result, the stent 20 is released from the stent housing tube 30.

[0034] The tip marker 45 is a ring-shaped member fixed to the outer surface of the inner tip tube 42 and is radiopaque. The tip marker 45 is used to determine the position of the tip of the stent 20 under radiographic fluoroscopy. The outer surface of the tip marker 45 is in contact with or close to the inner surface of the movable tube 31.

[0035] As shown in Figure 3, the reinforcing shaft 100 is a metal component that provides rigidity to the catheter 10. The reinforcing shaft 100 is one or more (in this embodiment, one) wires.

[0036] The base end 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 base shaft 70, the through hole 73 of the connecting tube 71, and the base tube 60. The tip end of the reinforcing shaft 100 is fixed to the outer surface of the tip inner tube 42 and the base inner tube 43 by the reinforcing shaft fixing tube 120.

[0037] As shown in Figures 2 to 4, the towing wire 80 is a wire used to pull the stent housing tube 30 in the proximal end direction X, thereby releasing the stent 20 from the stent housing tube 30. One or more towing wires 80 (two in this embodiment) are provided. In this embodiment, two towing wires 80 are positioned and fixed at opposing positions (180-degree offset positions) on the outer circumferential surface of the reduced diameter portion 33 of the movable tube 31. Preferably, the tip of each towing wire 80 fixed to the movable tube 31 is formed into a flat plate shape by press working or the like. Alternatively, the tip of the towing wire 80 may be formed into a curved plate shape so as to have a curved surface that can closely conform to the curved shape of the outer circumferential surface of the movable tube 31. This increases the contact area of ​​the towing wire 80 with the movable tube 31, the wire tip fixing tube 50, and the wire fixing tube 90. Therefore, the traction wire 80 can stably transmit the traction force, improve resistance to peeling from the movable tube 31, the wire tip fixing tube 50, and the wire fixing tube 90, and suppress an increase in the outer diameter of the catheter 10. Multiple traction wires 80 may be independent of each other, or they may be joined together so as to have a common proximal end. The proximal end of the traction wire 80 is fixed to the operating part 112 of the operating part 110, which will be described later. The traction wire 80 is positioned in the lumen of the proximal shaft 70, the through hole 73 of the connecting tube 71, the internal space 61 of the proximal tube 60, the lumen of the proximal side movable tube 32, and on the outside of the movable tube 31.

[0038] The towing wire 80 can preferably be made of a single wire or a twisted bundle of wires. The thickness of the towing wire 80 is not particularly limited, but is, for example, 0.15 mm to 0.30 mm.

[0039] The material used to construct the towing wire 80 is not particularly limited, but suitable materials include, for example, stainless steel wire (preferably high-tensile stainless steel for springs), piano wire (preferably nickel-plated or chromium-plated piano wire), or wires made from various metals such as superelastic alloy wire, Ni-Ti alloy, Cu-Zn alloy, Ni-Al alloy, tungsten, tungsten alloy, titanium, titanium alloy, cobalt alloy, tantalum, etc., or relatively high-rigidity polymer materials such as polyamide, polyimide, ultra-high molecular weight polyethylene, polypropylene, fluororesin, or combinations thereof as appropriate. The surface of the towing wire 80 may also be coated with a low-friction resin to increase its lubricity. Suitable low-friction resins include fluororesin, nylon 66, polyetheretherketone, high-density polyethylene, etc.

[0040] The stent 20 is formed in a substantially cylindrical shape from a superelastic alloy and, as shown in Figure 2, is housed in the movable tube 31 in a compressed state toward the central axis. The stent 20 expands as the stress load is removed by being pushed out from the opening at the tip of the movable tube 31, and returns to its pre-compression shape. The stent 20 is not limited in shape as long as it is a so-called self-expanding stent. As an example, the stent 20 may be formed by connecting multiple annular sections that are bent and formed into an annular shape in a row, thereby forming a single substantially cylindrical shape.

[0041] As shown in Figures 1 and 3, the operating unit 110 includes an operating body 111, an operating unit 112 that is rotatable relative to the operating body 111, a kink protector 113, a fixing unit 114 that fixes the base ends of the reinforcing shaft 100 and the base shaft 70 to the operating body 111, and a valve body 116.

[0042] The operation main body part 111 is the part grasped by the operator. The operation part 112 can rotate with respect to the operation main body part 111 by the operation of the operator, wind up the proximal end part of the traction wire 80, and traction the traction wire 80. The valve body 116 is for introducing the traction wire 80 extending in the proximal direction X from the inside of the proximal shaft 70 into the operation main body part 111 while maintaining a liquid-tight state while allowing movement in the long axis direction. The valve body 116 has a hole or slit through which the traction wire 80 can slide. The anti-kink protector 113 covers the proximal end side of the proximal shaft 70 and partially projects from the operation main body part 111 toward the distal end side. The anti-kink protector 113 suppresses kinking on the proximal end side of the proximal shaft 70.

[0043] Next, a method of using the catheter 10 according to the present embodiment will be described.

[0044] The operator percutaneously inserts the guide wire 200 (see FIG. 1) into the blood vessel and inserts the proximal end of the guide wire 200 into the guide wire lumen 41 from the tip opening 47. The guide wire 200 is led out from the proximal end opening 72.

[0045] Next, the operator inserts the catheter 10 into the blood vessel along the guide wire 200 and reaches the target site. Next, as shown in FIGS. 1 and 3(B), the operator rotates the operation part 112. As a result, the traction wire 80 is wound up by the operation part 112, and the traction wire 80 moves in the proximal direction X.

[0046] When the traction wire 80 moves in the proximal direction X, as shown in FIG. 2(B), since the distal end side of the traction wire 80 is fixed to the stent housing tube 30, the stent housing tube 30 moves in the proximal direction X. At this time, the proximal movable tube 32 of the stent housing tube 30 can enter the inside of the proximal tube 60. Since the proximal end surface of the stent 20 abuts against and is locked to the distal end surface of the proximal marker 46 of the inner tube 40, when viewed from the stent housing tube 30, the stent 20 moves toward the distal end side on the inner surface of the stent housing tube 30. As a result, the stent 20 is gradually released from the opening on the distal end side of the movable tube 31. By this release, the stent 20 expands by its own elastic force to expand the stenosis and is placed in the stenosis.

[0047] Next, a method for manufacturing the catheter 10 according to the present embodiment will be described.

[0048] The manufacturer fixes the traction wire 80 to the movable tube 31. As an example of fixing the traction wire 80 to the movable tube 31, as shown in FIG. 5(A), the manufacturer covers the outside of the reduced-diameter portion 33 of the movable tube 31 with a wire tip fixing tube 50 having a constant inner diameter and outer diameter along the long axis direction, and arranges the tips of the respective traction wires 80 at predetermined positions between the movable tube 31 and the wire tip fixing tube 50. The two traction wires 80 are arranged at opposing positions on the outer peripheral surface of the reduced-diameter portion 33. Next, the manufacturer supplies a liquid adhesive into the gap between the movable tube 31 and the wire tip fixing tube 50. After the liquid adhesive spreads and fills the narrow gap between the movable tube 31 and the wire tip fixing tube 50 by capillary action, it cures. Thereby, the traction wire 80 between the movable tube 31 and the wire tip fixing tube 50 is firmly fixed to the movable tube 31 and the wire tip fixing tube 50.

[0049] Next, the manufacturer places a wire fixing tube 90, whose inner and outer diameters are constant along the long axis, over the radially outer side of the base end of the movable tube 31. At this time, the base end of the wire fixing tube 90 extends further in the base direction X than the base end of the movable tube 31. At this time, the two traction wires 80 extending from the movable tube 31 in the base direction X are approximately parallel to the long axis of the movable tube 31 in the vicinity of the movable tube 31.

[0050] Next, as shown in Figure 5(B), the manufacturer inserts a cylindrical jig 300 between the wire fixing tube 90 and the towing wire 80 from the base end. That is, the two towing wires 80 are positioned inside the jig 300, and the wire fixing tube 90 is positioned outside the jig 300. To facilitate the insertion of the jig 300 into the wire fixing tube 90, the outer diameter of the jig 300 is preferably approximately the same as or slightly smaller than the inner diameter of the wire fixing tube 90. The inner diameter of the jig 300 is preferably smaller than the diameter D of the circumscribed circles of all (two in this embodiment) the towing wires 80 in a cross section perpendicular to the long axis (see Figure 4). This allows the inner circumference of the tip of the jig 300 to apply force to the towing wires 80 so that they bend.

[0051] When the jig 300 is inserted between the wire fixing tube 90 and the towing wire 80, as shown in Figure 5(B), the portion of the towing wire 80 extending from the base end of the movable tube 31 in the direction of the base end X is subjected to force from the inner circumference of the tip of the jig 300 and bends inward. The greater the insertion amount of the jig 300, the greater the force the towing wire 80 receives from the inner circumference of the tip of the jig 300 and bends, resulting in it moving away from the inner surface of the wire fixing tube 90. As shown in Figures 5(B) and 6, in the longitudinal axis direction, the position of the base end of the movable tube 31 is taken as the reference position P, and the jig 300 is inserted to a position at a distance L from the reference position P in the direction of the base end X. The portion of the towing wire 80 extending from the reference position P in the direction of the base end X is inclined inward at an angle θ with respect to the longitudinal axis of the movable tube 31. The angle θ increases as the tip of the jig 300 approaches the reference position P, that is, as the distance L approaches 0 mm.

[0052] Next, as shown in Figures 5(C) and 6, the manufacturer supplies liquid adhesive from the tip side into the gap between the movable tube 31 and the wire fixing tube 90. The liquid adhesive spreads and fills the narrow gap between the movable tube 31 and the wire tip fixing tube 50 by capillary action, and then hardens. When the inclination angle θ of the traction wire 80 is small, the gap between the portion of the traction wire 80 extending from the reference position P towards the proximal end X and the inner circumferential surface of the wire fixing tube 90 is small, so the liquid adhesive flows into this gap by capillary action. In contrast, when the inclination angle θ of the traction wire 80 is large, the gap between the portion of the traction wire 80 extending from the reference position P towards the proximal end X and the inner circumferential surface of the wire fixing tube 90 is large, so the flow of liquid adhesive into this gap is suppressed. However, if the inclination angle θ of the traction wire 80 is too large, the traction wire 80 will bend too much, which may interfere with the inner tube 40 when assembled as the catheter 10, so this is undesirable. Furthermore, if the distance L from the reference position P to the tip of the jig 300 is reduced too much in order to increase the inclination angle θ of the towing wire 80, the tip of the jig 300 may come too close to the base end of the movable tube 31, and liquid adhesive may adhere to the tip of the jig 300. For this reason, it is preferable that the inclination angle θ of the towing wire 80 is neither too large nor too small.

[0053] After the adhesive has hardened, the manufacturer pulls the jig 300 out from between the wire fixing tube 90 and the traction wire 80 in the direction X towards the base end, as shown in Figure 5(D). After this, the manufacturer inserts the base-side movable tube 32 from the base end side between the wire fixing tube 90 and the traction wire 80 (see Figure 2). At this time, since the base end of the first joint 91 is located at or towards the tip of the reference position P in the region sandwiched between the traction wire 80 and the wire fixing tube 90, the base-side movable tube 32 can be inserted to an appropriate position near the base end of the movable tube 31.

[0054] Next, the manufacturer supplies liquid adhesive from the proximal end to the gap between the proximal end movable tube 32 and the wire fixing tube 90. The liquid adhesive spreads and fills the narrow gap between the proximal end movable tube 32 and the wire fixing tube 90 by capillary action, and then hardens. As a result, the movable tube 31 and the proximal end movable tube 32 are connected by the wire fixing tube 90. After this, the manufacturer assembles the other components to complete the manufacture of the catheter 10.

[0055] As shown in Figure 5(A), multiple movable tubes 31 were prepared with the ends of the towing wires 80 already fixed by wire end fixing tubes 50. As shown in Figures 5(B) to 5(D), a test was conducted in which a wire fixing tube 90 was placed over the movable tubes 31 and adhesive was supplied to form a first joint 91. The outer diameter of the reduced diameter portion 33 (base end) of the movable tube 31 used in the test was 1.60 mm and the wall thickness was 0.085 mm. The material of the movable tube 31 was nylon 12. The radial thickness of each towing wire 80 was 0.25 mm and the width in the direction perpendicular to the thickness was 0.25 mm. The material of the towing wires 80 was stainless steel. The outer diameter of the jig 300 was 1.47 mm and the inner diameter was 0.91 mm. The material of the jig 300 was stainless steel. The length in the long axis direction of the wire fixing tube 90 was 13 mm, the inner diameter was 1.79 mm and the thickness was 0.075 mm. The wire fixing tube 90 was made of nylon 12. The adhesive used was an ultraviolet / visible light curing acrylic resin adhesive.

[0056] The first joint 91 was formed by covering the movable tube 31 with the wire fixing tube 90 and supplying adhesive under the conditions that the distance L from the reference position P where the base end of the movable tube 31 is located to the tip of the jig 300 is 0 mm (Test Example 1), 1 mm (Test Example 2), 2 mm (Test Example 3), 3 mm (Test Example 4), and 4 mm (Test Example 5). Table 1 shows the results for Test Examples 1 to 5. The average angle is the average value obtained by measuring the maximum inclination angle θ detected in each traction wire 80 when the jig 300 is inserted. The maximum angle is the larger of the maximum inclination angles θ detected in each traction wire 80 when the jig 300 is inserted.

[0057]

[0058] As a result, in Test Example 1, the formed first joint 91 protruded from the reference position P in the base end direction X, as shown in the photograph in Figure 7. In Test Example 1, it is thought that the tip of the jig 300 reached the reference position P, the inclination angle θ of the traction wire 80 became too large, and the adhesive flowed out beyond the reference position in the base end direction X, exceeding the surface tension.

[0059] In Test Example 5, as shown in the photograph in Figure 8, the formed first joint portion 91 protruded from the reference position P toward the base end X. This is thought to be because the inclination angle θ of the traction wire 80 was too small when the jig 300 was inserted, causing the adhesive to flow out between the portion of the wire fixing tube 90 closer to the base end than the reference position P and the traction wire 80 due to capillary action.

[0060] Figure 9 shows a photograph of Test Example 2. In Test Examples 2 to 4, the first joint portion 91 did not protrude from the reference position P in the base end direction X.

[0061] When the jig 300 is inserted, the inclination angle θ is preferably between 3.171 degrees and 4.599 degrees, when evaluated by the average angle. When the jig 300 is inserted, the inclination angle θ is preferably between 3.601 degrees and 5.336 degrees, when evaluated by the maximum angle. The distance L from the reference position P to the tip of the jig 300 is preferably between 1 mm and 3 mm.

[0062] As described above, the catheter 10 according to this embodiment includes a movable tube 31 that can move along the long axis, a wire fixing tube 90 positioned radially outside the proximal end of the movable tube 31 and extending further towards the proximal end than the movable tube 31, at least one traction wire 80 having a tip and a proximal end and sandwiched between the movable tube 31 and the wire fixing tube 90, and a first joint portion 91 (joint portion) positioned between the outer circumferential surface of the movable tube 31 and the inner circumferential surface of the wire fixing tube 90 and joining the traction wire 80 to the movable tube 31 and the wire fixing tube 90. In the long axis direction of the movable tube 31, at least a portion of the proximal end of the first joint portion 91 in the region sandwiched between the traction wire 80 and the wire fixing tube 90 is located on or towards the tip of the reference position P where the proximal end of the movable tube 31 is located. As a result, the catheter 10 has a first joint 91 that connects the traction wire 80 to the movable tube 31, which does not protrude from the proximal end of the movable tube 31 in the direction X from the proximal end. This suppresses the generation of foreign matter due to detachment from the first joint 91 and also suppresses interference of the first joint 91 with other components.

[0063] Furthermore, the catheter 10 has a proximal movable tube 32 that is positioned on the proximal side of the movable tube 31 which is movable along the long axis and is movable along the long axis together with the movable tube 31. The proximal end of the wire fixing tube 90 is positioned radially outward of the proximal movable tube 32, and the traction wire 80 is positioned radially inward of the proximal movable tube 32. Since the first joint portion 91 does not protrude from the proximal end of the movable tube 31 in the proximal direction X, it is possible to prevent it from coming into contact with the proximal movable tube 32 and falling off, interfering with the proximal movable tube 32 and making assembly of the catheter 10 difficult, or hindering the operation of the catheter 10.

[0064] Furthermore, the catheter 10 is positioned on the distal side of the wire fixing tube 90 and radially outward of the movable tube 31, sandwiching the traction wire 80 between the catheter and the movable tube 31, and has a wire tip fixing tube 50 that fixes the traction wire 80 to the movable tube 31. As a result, the catheter 10 connects the traction wire 80 to the movable tube 31 not only by the wire fixing tube 90 but also by the wire tip fixing tube 50, so the movable tube 31 can be firmly fixed to the traction wire 80.

[0065] Furthermore, the catheter 10 has two traction wires 80, which are positioned opposite each other in the circumferential direction of the movable tube 31. This prevents the first joint 91 from protruding from the proximal end of the movable tube 31 in the proximal direction X between each traction wire 80 and the wire fixing tube 90.

[0066] Furthermore, the movable tube 31 houses the expandable stent 20 (deployed object) in a contracted state, and the deployed object can be released by being pulled by the traction wire 80. Since the traction wire 80 is firmly fixed to the movable tube 31 by the wire fixing tube 90 of the catheter 10, it is possible to prevent the traction wire 80 from detaching from the movable tube 31 when releasing the stent 20. In addition, since the first joint portion 91 does not protrude from the proximal end of the movable tube 31 in the proximal direction X, it is possible to prevent it from hindering the operation of releasing the stent 20.

[0067] Furthermore, the method for manufacturing the catheter 10 according to this embodiment is a method for manufacturing the catheter 10 having a movable tube 31 that can move along the long axis and a traction wire 80 fixed to the outer surface of the movable tube 31, comprising the steps of: arranging a wire fixing tube 90 so as to cover the radially outer side of the proximal end of the movable tube 31 and to extend further toward the proximal end than the movable tube 31, and arranging the traction wire 80 between the outer surface of the movable tube 31 and the inner surface of the wire fixing tube 90; and arranging a cylindrical jig 3 between the wire fixing tube 90 and the traction wire 80. The procedure includes the steps of: inserting the tool 00 from the base end side and tilting the portion of the traction wire 80 extending from the movable tube 31 toward the base end X inward with respect to the long axis of the movable tube 31; supplying adhesive to the gap between the movable tube 31 and the wire fixing tube 90 from the tip side of the wire fixing tube 90; curing the adhesive to form a first joint portion 91 that joins the traction wire 80 to the movable tube 31 and the wire fixing tube 90; and pulling out the jig 300 from between the wire fixing tube 90 and the traction wire 80. When the portion of the traction wire 80 extending from the movable tube 31 toward the base end X is tilted inward with respect to the long axis of the movable tube 31, the portion of the traction wire 80 extending from the movable tube 31 toward the base end X separates from the wire fixing tube 90. In this state, because adhesive is supplied to the gap between the movable tube 31 and the wire fixing tube 90, the formed first joint portion 91 is less likely to protrude from the base end of the movable tube 31 toward the base end X. Therefore, this manufacturing method can suppress the generation of foreign matter from the first joint 91 and can also suppress interference between the first joint 91 and other members.

[0068] It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made by those skilled in the art within the technical framework of the present invention. For example, the shape of the wire fixing tube 90 when forming the first joint 91 may be such that the inner diameter increases as it moves away from the reference position P in the direction of the base end X. In this case, the wire fixing tube 90 on the base end side of the reference position P is away from the traction wire 80 even without inserting the jig 300, so that the first joint 91 does not protrude in the direction of the base end X from the reference position P.

[0069] Furthermore, by using a high-viscosity adhesive (for example, with a viscosity of 3500 to 7500 mPa·s) to form the first joint 91, the inflow rate of the adhesive is slowed down, and the position in which the first joint 91 is formed can be adjusted with high precision.

[0070] Furthermore, the traction wire 80 may be fixed to the proximal movable tube 32 of the stent housing tube 30, rather than to the movable tube 31. Also, the present invention may be applied to catheters other than the catheter 10 that transports the stent 20. Therefore, the deployed object does not have to be the stent 20.

[0071] This application is based on Japanese Patent Application No. 2024-167057, filed on September 26, 2024, and its disclosures are referenced and incorporated as a whole.

[0072] 10 Catheter 20 Stent (Deployment) 30 Stent housing tube 31 Movable tube 32 Proximal end movable tube 33 Diameter reduction section 50 Wire tip fixing tube 80 Traction wire 90 Wire fixing tube 91 First joint 92 Second joint 300 Jig X Proximal end direction

Claims

1. A catheter comprising: a movable tube that is movable along its long axis; a wire fixing tube positioned radially outward from the proximal end of the movable tube and extending further toward the proximal end than the movable tube; at least one traction wire having a tip and a proximal end and sandwiched between the movable tube and the wire fixing tube; and a joint positioned between the outer circumferential surface of the movable tube and the inner circumferential surface of the wire fixing tube for joining the traction wire to the movable tube and the wire fixing tube, wherein, in the long axis direction of the movable tube, at least a portion of the proximal end of the joint in the region sandwiched between the traction wire and the wire fixing tube is located on or toward the tip of the reference position where the proximal end of the movable tube is located.

2. The catheter according to claim 1, wherein it has a proximal movable tube that is positioned on the proximal side of the movable tube which is movable along the longitudinal axis and is movable together with the movable tube along the longitudinal axis, the proximal end of the wire fixing tube is positioned radially outward of the proximal movable tube, and the traction wire is positioned radially inward of the proximal movable tube.

3. The catheter according to claim 1 or 2, characterized in that it has a wire tip fixing tube located at the tip of the wire fixing tube and radially outward of the movable tube, which sandwiches the traction wire between itself and the movable tube and fixes the traction wire to the movable tube.

4. The catheter according to claim 1 or 2, wherein it has two traction wires, the two traction wires are positioned opposite each other in the circumferential direction of the movable tube.

5. The catheter according to claim 1 or 2, characterized in that the movable tube houses an expandable deployable in a contracted state and the deployable can be released by being pulled by the traction wire.

6. A method for manufacturing a catheter, comprising a movable tube that is movable along its long axis and a traction wire fixed to the outer surface of the movable tube, the method comprising: arranging a wire fixing tube so as to cover the radially outer side of the proximal end of the movable tube and to extend further toward the proximal end than the movable tube, and arranging the traction wire between the outer surface of the movable tube and the inner surface of the wire fixing tube; inserting a cylindrical jig between the wire fixing tube and the traction wire from the proximal end side, and tilting the portion of the traction wire extending from the movable tube toward the proximal end inward with respect to the long axis of the movable tube; supplying adhesive to the gap between the movable tube and the wire fixing tube from the tip side of the wire fixing tube; curing the adhesive to form a joint for joining the traction wire to the movable tube and the wire fixing tube; and withdrawing the jig from between the wire fixing tube and the traction wire.

Images