JP2009202030A - Guide wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a guide wire with high joint strength and excellent operability. <P>SOLUTION: The guide wire 1 is to be inserted into a catheter and used, and includes a fourth wire 6 disposed to a distal end side, a second wire 3 disposed to a proximal end side of the fourth wire 6, a first wire 2 disposed to the distal end side of the fourth wire 6, a third wire 5 disposed to the distal end side of the first wire 2, and a helical coil 4. In the guide wire 1, the first wire 2 is constituted of a Ni-Ti based alloy, the second wire 3 is constituted of a material with elastic modulus higher than that of the constitution material of the first wire 2, and the third wire 5 is constituted of a Ni based alloy mainly containing Ni. The first wire 2 and the third wire 5 are jointed by welding. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a guide wire, and particularly to a guide wire used when a catheter is introduced into a body cavity such as a blood vessel.

  The guide wire can be used for the treatment of a site where surgery is difficult, such as PTCA (Percutaneous Transluminal Coronary Angioplasty), or for the purpose of minimally invasive to the human body, Used to guide catheters used for examinations such as angiography. A guide wire used for PTCA surgery is inserted to the vicinity of the target vascular stenosis portion together with the balloon catheter with the tip of the guide wire protruding from the tip of the balloon catheter. Guide to near.

  The blood vessel is intricately curved, and the guide wire used to insert the balloon catheter into the blood vessel has flexibility and resilience to moderate bending, and pushability to transmit the operation at the proximal end to the distal side. In addition, torque transmission properties (collectively referred to as “operability”) and kink resistance (bending resistance) are required.

  Further, in order to select a blood vessel branch, a doctor often uses a guide wire by bending the distal end portion of the guide wire into a desired shape, and the distal end portion of the guide wire can be bent into a desired shape. (Reshape) characteristics are required.

  By the way, as for the conventional guide wire, the core material is substantially composed of one kind of material, and in order to improve the operability of the guide wire, a material having a relatively high elastic modulus is used. The flexibility of the tip is lost. Further, if a material having a relatively low elastic modulus is used in order to obtain the flexibility of the distal end portion of the guide wire, the operability on the proximal end side of the guide wire is lost. Thus, it has been difficult to satisfy the required flexibility and operability with one kind of core material.

  In order to improve such a defect, a guide wire in which a plurality of metal wires are connected using, for example, a tubular connecting member or the like so as to satisfy various characteristics has been proposed. However, in such a guide wire, in order to obtain a high bonding strength between the metal wires, there is a problem that the structure becomes complicated and a lot of labor and time are required for manufacturing.

  An object of the present invention is to provide a guide wire having high bonding strength and excellent operability.

Such an object is achieved by the following inventions (1) to (5).
(1) a linear first wire arranged on the tip side and made of a Ni-Ti alloy;
A linear second wire that is disposed on the proximal end side of the first wire and is made of a material having a larger elastic modulus than the constituent material of the first wire;
A linear third wire arranged on the tip side of the first wire and made of a Ni-based alloy mainly composed of Ni;
The guide wire, wherein the first wire and the third wire are connected by welding.

  (2) The guide wire according to (1), wherein the third wire is disposed so as to extend the first wire toward a distal end side.

  (3) The guide wire according to (1) or (2), wherein a distal end of the first wire and a proximal end of the third wire are connected by welding.

  (4) The guide wire according to any one of (1) to (3), wherein the second wire is made of stainless steel or a cobalt-based alloy.

  (5) The guide wire according to any one of (1) to (4), wherein the Ni-based alloy is a Ni-Cr-based alloy or a Ni-Co-based alloy.

  It is preferable that the third wire is connected to the distal end side of the first wire by welding.

  It is preferable that the third wire is made of a wire that has elasticity and can be reshaped.

  It is preferable that the guide wire has an outer diameter gradually decreasing portion in which the outer diameter gradually decreases in the axial direction from the middle in the axial direction.

  The welded portion between the first wire and the third wire is preferably located in the middle of the outer diameter gradually decreasing portion.

  It is preferable that a fourth wire is provided between the first wire and the second wire, and a welded portion between the fourth wire and the second wire is located in the middle of the outer diameter gradually decreasing portion.

  It is preferable that the connection end surfaces of the wires are substantially perpendicular to the axial direction of the guide wire.

The welding is preferably by butt resistance welding.
It is preferable that the welds between the wires are used so that they are all located in the living body.

As described above, according to the present invention, various characteristics (for example, pushability, torque transmission, kink resistance, etc.) can be obtained with a simple configuration, and the first wire and the third wire can be obtained. Since the bond strength is high, excellent operability can be obtained.
Moreover, the said effect improves more by selecting the constituent material of each wire suitably.

It is a longitudinal cross-sectional view which shows 1st Embodiment of the guide wire of this invention. It is a figure which shows the procedure which connects the 2nd wire and 4th wire in the guide wire shown in FIG. It is a schematic diagram for demonstrating the usage example of the guide wire of this invention. It is a schematic diagram for demonstrating the usage example of the guide wire of this invention. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the guide wire of this invention.

  Hereinafter, the guide wire of the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

<First Embodiment>
First, a first embodiment of the guide wire of the present invention will be described.

  FIG. 1 is a longitudinal sectional view showing a first embodiment of the guide wire of the present invention, and FIG. 2 is a diagram showing a procedure for connecting the wires in the guide wire shown in FIG. For convenience of explanation, the right side in FIG. 1 is referred to as “base end” and the left side is referred to as “tip”. Further, in FIG. 1, for the sake of easy understanding, the length direction of the guide wire is shortened and the thickness direction of the guide wire is exaggerated, and the ratio between the length direction and the thickness direction is schematically illustrated. It is very different from the actual one.

  A guide wire 1 shown in FIG. 1 is a catheter guide wire used by being inserted into a catheter, and includes a fourth wire 6 disposed on the distal end side and a second wire disposed on the proximal end side of the fourth wire 6. The wire 3, the first wire 2 disposed on the distal end side of the fourth wire 6, the third wire 5 disposed on the distal end side of the first wire 2, and the spiral coil 4 are provided. The total length of the guide wire 1 is not particularly limited, but is preferably about 200 to 5000 mm. Further, the outer diameter of the guide wire 1 is not particularly limited, but it is usually preferably about 0.2 to 1.2 mm.

  The first wire 2 is a flexible wire. Although the length of the 1st wire 2 is not specifically limited, It is preferable that it is about 20-1000 mm.

  In the present embodiment, the outer diameter of the first wire 2 gradually decreases toward the distal end over substantially the entire length thereof. As a result, the rigidity (bending rigidity, torsional rigidity) of the first wire 2 can be gradually decreased toward the distal end direction. As a result, the guide wire 1 obtains good flexibility at the distal end portion, and the blood vessel Follow-up performance and safety can be improved, and bending can also be prevented.

  In the configuration shown in the drawing, the first wire 2 has a tapered shape in which the outer diameter gradually decreases gradually toward the distal end over substantially the entire length thereof. The taper angle of the tapered portion of the first wire 2 may be constant along the longitudinal direction or may vary along the longitudinal direction.

  Further, unlike the drawing, the first wire 2 may have a portion with a constant outer diameter along the longitudinal direction. For example, the first wire 2 has taper-shaped tapered portions whose outer diameter gradually decreases in the distal direction, and is formed at a plurality of locations along the longitudinal direction, and the outer diameter is longer between these tapered portions and the tapered portion. A certain part may be formed along the direction. Even in such a case, the same effect as described above can be obtained. Further, the first wire 2 may have a constant outer diameter along the longitudinal direction of the first wire 2, unlike the illustration.

  The constituent material of the first wire 2 is preferably an alloy (including a superelastic alloy) exhibiting pseudoelasticity. More preferably, it is a superelastic alloy. Since the superelastic alloy is relatively flexible and has a resilience and is difficult to bend, the guide wire 1 can be sufficiently formed in the tip side portion by configuring the first wire 2 with the superelastic alloy. Flexibility and resilience to bending can be obtained, follow-up to complicatedly curved and bent blood vessels can be improved, and more excellent operability can be obtained. Even if the first wire 2 repeatedly bends and bends, Since the 1 wire 2 is not bent due to its restoring property, it is possible to prevent the operability from being deteriorated due to the bent wire being attached to the first wire 2 during use of the guide wire 1.

  Alloys exhibiting pseudoelasticity (pseudoelastic alloys) include any shape of a stress-strain curve caused by tension, and include those in which transformation points such as As, Af, Ms, and Mf can be remarkably measured, and those that cannot. This includes everything that is greatly deformed (strained) by the stress and returns almost to its original shape by removing the stress.

  The preferred composition of the superelastic alloy is Ni-Ti alloy such as Ni-Ti alloy of 49-52 atomic% Ni, Cu-Zn alloy of 38.5-41.5 wt% Zn, 1-10 wt% X Cu-Zn-X alloy (X is at least one of Be, Si, Sn, Al, and Ga), 36-38 atomic% Al-Ni-Al alloy, and the like. Of these, the Ni-Ti alloy is particularly preferable.

  The second wire 3 is disposed (installed) on the proximal end side of the fourth wire 6. The second wire 3 is an elastic wire. Although the length of the 2nd wire 3 is not specifically limited, It is preferable that it is about 20-4800 mm.

  The second wire 3 is made of a material having a higher elastic modulus (Young's modulus (longitudinal elastic modulus), rigidity (transverse elastic modulus), and bulk elastic modulus) than the constituent material of the first wire 2. Thereby, moderate rigidity (bending rigidity, torsional rigidity) is obtained for the second wire 3, the guide wire 1 becomes so-called strong and the pushability and torque transmission performance are improved, and more excellent insertion operability. Is obtained.

  The constituent material (material) of the 2nd wire 3 is not specifically limited, Stainless steel (For example, SUS304, SUS303, SUS316, SUS316L, SUS316J1, SUS316J1L, SUS405, SUS430, SUS434, SUS444, SUS429, SUS430F, SUS302, etc. Varieties), piano wires, cobalt-based alloys, pseudoelastic alloys, and the like can be used, but stainless steel or cobalt-based alloys are preferred. By configuring the second wire 3 with stainless steel or a cobalt-based alloy, the guide wire 1 can obtain better pushability and torque transmission.

  A fourth wire 6 is disposed (installed) between the first wire 2 and the second wire 3, and ends of the wires 2, 3, 6 are connected (connected) by welding. Yes. The 4th wire 6 is a wire which has elasticity. Although the length of the 4th wire 6 is not specifically limited, It is preferable that it is about 20-1000 mm.

  The fourth wire 6 is made of a material whose bonding property to the first wire 2 by welding is higher than that of the second wire 3 to welding to the fourth wire 6. Even when the first wire 2 and the second wire 3 are directly connected by welding, a sufficient bond strength can be obtained in these welds, but by configuring the fourth wire 6 with the above material, A high joint strength (weldability) is obtained at the welded portion 16 between the fourth wire 6 and the second wire 3, and the welded portion 17 between the fourth wire 6 and the first wire 2 is equal to or higher than that. Particularly high bond strength can be obtained. Therefore, the guide wire 1 has excellent operability.

  Such a constituent material of the fourth wire 6 can be appropriately selected according to the relationship of the bonding properties of the wires 2, 3, 6 described above. For example, a nickel-based alloy (Ni-based alloy mainly composed of Ni) Various metal materials such as superelastic alloy and stainless steel can be used. Furthermore, an alloy that forms a solid solution with Ni as a main component or an alloy component is preferable, and examples thereof include a Ni—Cr alloy, a Ni—Cu alloy, and a Fe—Ni alloy.

  From the viewpoint of further improving the bonding strength in the welded portion 17, the constituent material of the fourth wire 6 preferably includes at least one element included in the constituent material of the first wire 2, and the first wire When the constituent material 2 is a superelastic alloy, in particular, a Ni—Ti alloy, a nickel-based alloy (a Ni alloy mainly composed of Ni) is preferable.

  On the other hand, from the viewpoint of further improving the bond strength in the welded portion 16, the constituent material of the fourth wire 6 preferably includes at least one element among the elements contained in the constituent material of the second wire 3, When the constituent material of the 2-wire 3 is stainless steel or a cobalt-based alloy, the constituent material of the fourth wire 6 is preferably a metal material (alloy) mainly composed of chromium or cobalt.

  For this reason, when the first wire 2 is made of a superelastic alloy (particularly, Ni—Ti alloy) and the second wire 3 is made of stainless steel or cobalt alloy, The constituent material is preferably a Ni-based alloy mainly containing Ni, and a Ni-Cr-based alloy or a Ni-Co-based alloy is optimal. As a result, the bond strength at the welded portion 16 is increased, and the bond strength at the welded portion 17 is particularly high, which is equal to or higher than that. As a result, the guidewire 1 is particularly excellent in durability and extremely high. Safety is high.

  The elastic modulus of the Ni-Cr alloy or Ni-Co alloy is preferably an intermediate value between the elastic modulus of the superelastic alloy and the elastic modulus of the stainless steel or cobalt alloy. In the wire 1, the rigidity (bending rigidity, torsional rigidity) gradually decreases from the middle in the longitudinal direction (axial direction) toward the distal direction. As a result, the kink resistance (bending resistance) in the vicinity of the welds 16 and 17 is improved, and the guide wire 1 can obtain excellent operability.

  Further, the proximal end portion of the third wire 5 is preferably connected (connected) to the distal end portion of the first wire 2 by welding. The third wire 5 is a wire that has elasticity and can be reshaped. Here, “reshapable” means that the shape can be maintained by bending the wire into a desired shape.

  The guide wire 1 is usually used by a doctor by bending the distal end portion of the guide wire 1 into a desired shape in order to select a blood vessel branch. In this way, the guide wire 1 is a third wire that can be reshaped. By having 5, it is possible to easily and reliably reshape (shape) the distal end portion of the guide wire 1. As a result, the operability during the operation of inserting the guide wire 1 into the living body is greatly improved.

  In the configuration shown in the figure, the third wire 5 has a taper shape in which the outer diameter gradually decreases gradually toward the distal end over substantially the entire length thereof. The taper angle of the tapered portion of the third wire 5 may be constant along the longitudinal direction or may vary along the longitudinal direction.

  Further, unlike the drawing, the third wire 5 may have a portion with a constant outer diameter along the longitudinal direction. For example, the third wire 5 is formed with a plurality of taper-shaped taper portions whose outer diameters gradually decrease in the distal direction along the longitudinal direction, and the outer diameter is long between the taper portions and the taper portions. A certain part may be formed along the direction. Even in such a case, the same effect as described above can be obtained. Also, the third wire 5 may have a constant outer diameter along the longitudinal direction at the tip side, unlike the illustration.

  The third wire 5 can form a desired shape and can maintain the shape, and a nickel-base alloy can be used as a constituent material (raw material).

  The constituent material of the third wire 5 is preferably the same as the constituent material of the fourth wire 6. That is, the constituent material of the third wire is preferably a Ni-based alloy (nickel-based alloy) mainly composed of Ni, and a Ni-Cr-based alloy or a Ni-Co-based alloy is optimal. By configuring the third wire 5 with a nickel-based alloy, particularly excellent reshapability is exhibited. Moreover, when the 1st wire 2 is comprised with a Ni-Ti type alloy, the joining property by welding with the 1st wire 2 of the 3rd wire 5 further improves.

  The length of the third wire 5 is not particularly limited, but is preferably about 20 to 1000 mm.

  The coil 4 is installed (arranged) so as to cover the entire length (the whole) in the longitudinal direction (axial direction) of the third wire 5 and a part of the first wire 2. The coil 4 is composed of a member obtained by winding a wire (thin wire) in a spiral shape. In the configuration shown in the figure, the third wire 5 is inserted through the substantially central portion inside the coil 4. The third wire 5 is inserted in a non-contact manner with the inner surface of the coil 4.

  In the configuration shown in the figure, the coil 4 has a slight gap between the spirally wound wires in a state where no external force is applied, but unlike the illustration, the coil 4 is spiraled in a state where no external force is applied. Wires wound in a shape may be densely arranged without a gap.

  The coil 4 is preferably made of a metal material. Examples of the metal material constituting the coil 4 include stainless steel, superelastic alloy, cobalt-based alloy, noble metals such as gold, platinum, and tungsten, or alloys containing these. In particular, when the guide wire 1 is made of an X-ray opaque material such as a noble metal, X-ray contrast can be obtained in the guide wire 1, and the guide wire 1 can be inserted into the living body while confirming the position of the tip under X-ray fluoroscopy. It is possible and preferable. Moreover, you may comprise the coil 4 with the material from which the front end side and base end side differ. For example, the distal end side may be constituted by a coil made of an X-ray opaque material, and the proximal end side may be constituted by a coil made of a material (such as stainless steel) that relatively transmits X-rays. The total length of the coil 4 is not particularly limited, but is preferably about 5 to 500 mm.

  The proximal end portion and the distal end portion of the coil 4 are fixed to the third wire 5 (the distal end portion of the guide wire 1) and the first wire 2 by fixing materials 11 and 12, respectively. Further, an intermediate portion (position near the tip) of the coil 4 is fixed to the third wire 5 by a fixing material 13. The fixing materials 11, 12 and 13 are made of solder (brazing material). The fixing materials 11, 12 and 13 are not limited to solder, and may be adhesives. Moreover, the fixing method of the coil 4 is not limited to a fixing material, and for example, welding may be used. In order to prevent damage to the inner wall of the blood vessel, the distal end surface of the fixing material 12 is preferably rounded.

  In the present embodiment, since such a coil 4 is provided, the third wire 5 is covered with the coil 4 and has a small contact area, so that the sliding resistance can be reduced. The operability of 1 is further improved.

  In the case of the present embodiment, the coil 4 has a circular cross section of the wire. However, the present invention is not limited to this, and the cross section of the wire is, for example, elliptical or quadrangular (particularly rectangular). Also good.

  Further, the coil 4 is not limited to the configuration shown in FIG. 1, that is, the configuration covering the entire length of the third wire 5 and the middle of the first wire 2 in the longitudinal direction. 5 may cover the middle of the longitudinal direction of the fifth wire 5, or may cover substantially the entire length of the third wire 5 in the longitudinal direction or the middle of the fourth wire 6 in the longitudinal direction. .

  The guide wire 1 as described above may have a synthetic resin coating (plastic jacket) that covers all or part of the outer peripheral surface (outer surface) thereof. Thereby, friction with the inner wall of the catheter used with the guide wire 1 is reduced, the slidability is improved, and the operability of the guide wire 1 in the catheter becomes better. Examples of the constituent material of the coating include polyethylene, polyvinyl chloride, polyester, polypropylene, polyamide, polyurethane, polystyrene, polycarbonate, fluorine-based resin (PTFE, ETFE, etc.), silicone resin, and other various elastomers, or these These composite materials are preferably used. In particular, those having flexibility and softness equivalent to or lower than those of the first wire 2 are preferable. Further, the place where such a coating is provided is not particularly limited, and may be provided, for example, on almost the entire guide wire 1, and a part of the guide wire 1 (for example, the first wire 2, the fourth wire 6, and the like). It may be provided only on the outer peripheral surface of the second wire 3.

  Further, all or a part of the outer peripheral surface of the guide wire 1 may be subjected to processing for suppressing friction generated by contact with the inner wall of the catheter used together with the guide wire 1. Thereby, friction with a catheter inner wall is suppressed and the operativity of the 2nd wire 3 in a catheter becomes a better thing. As this treatment, for example, a coating (not shown) made of a hydrophilic material or a hydrophobic material can be provided on the outer peripheral surface of the guide wire 1.

  Examples of the hydrophilic material constituting the coating include cellulose-based polymer materials, polyethylene oxide-based polymer materials, and maleic anhydride-based polymer materials (for example, maleic anhydride such as methyl vinyl ether-maleic anhydride copolymer). Acid copolymer), acrylamide polymer substances (for example, polyacrylamide, polyglycidyl methacrylate-dimethylacrylamide (PGMA-DMAA) block copolymer), water-soluble nylon, polyvinyl alcohol, polyvinylpyrrolidone, and the like. Moreover, as a hydrophobic material which comprises a film, fluororesins, such as polytetrafluoroethylene, a silicone type material, etc. are mentioned, for example.

  In this guide wire 1, the third wire 5 and the first wire 2, the first wire 2 and the fourth wire 6, and the fourth wire 6 and the second wire 3 are connected (fixed) to each other by welding. ing. As a result, the welded portion (connecting portion) 16 between the fourth wire 6 and the second wire 3 has high bonding strength (joinability), and the welded portion (connecting portion) between the fourth wire 6 and the first wire 2 is obtained. ) 17 can obtain a high bond strength (joinability) equal to or higher than that of the welded portion 16, and therefore the guide wire 1 can reliably provide the torsional torque and the pushing force from the second wire 3 with the fourth wire 6 and the first wire 1. It is transmitted to the wire 2 and the third wire 5.

  As described above, in the present invention, the fourth wire 6 has a characteristic material, that is, the joining property of the fourth wire 6 to the first wire 2 by welding is the joining of the second wire 3 to the fourth wire 6 by welding. By using a material that is higher than the weldability, a high bond strength (weldability) can be obtained in the welded portion 16, and a high bond strength (weldability) equivalent to or higher than that can be obtained in the welded portion 17. Yes.

  In the present embodiment, the connection end surface 31 of the second wire 3 to the fourth wire 6, the connection end surface 52 of the fourth wire 6 to the second wire 3, the connection end surface 51 of the fourth wire 6 to the first wire 2, and the first wire. The connection end surface 22 of the second wire 6 to the fourth wire 6, the connection end surface 21 of the first wire 2 to the third wire 5, and the connection end surface 61 of the third wire 5 to the first wire 2 are all axes of the guide wire 1. Although it is a plane substantially perpendicular to the direction (longitudinal direction), the processing for forming the connection end faces 21, 22, 31, 51, 52, 61 is extremely easy. The above effects can be achieved without complicating the manufacturing process.

  Note that, unlike the illustrated configuration, each of the connection end faces 21, 22, 31, 51, 52, 61 may be inclined with respect to a plane perpendicular to the axial direction (longitudinal direction) of the guide wire 1 or may be a concave surface. Or it may be convex.

  The method for welding the wires 2, 3, 5, and 6 is not particularly limited, and examples thereof include butt resistance welding such as spot welding using a laser and butt seam welding. Is preferred. Thereby, each welding part 16, 17, 18 can obtain higher bond strength, respectively.

  In such a guide wire 1, the outer diameters of the third wire 5, the first wire 2, and the fourth wire 6 are welded between the welded portion 16 and the welded portion 17 (the base end 151 of the outer diameter gradually decreasing portion 15). It is gradually decreased toward the distal end from the welded portion 18 to the position on the distal end side (the distal end 152 of the outer diameter gradually decreasing portion 15) across the portions 17 and 18. In other words, the guide wire 1 has the outer diameter gradually decreasing portion 15 whose outer diameter gradually decreases from the middle of the axial direction (longitudinal direction) toward the distal end, and the welded portion 16 has the outer diameter gradually decreasing portion 15. Further, the welds 17 and 18 are located between the base end 151 of the outer diameter gradually decreasing portion 15 and the tip 152 of the outer diameter gradually decreasing portion 15 (in the middle of the outer diameter gradually decreasing portion 15). ing. As a result, the rigidity (bending rigidity, torsional rigidity) of the portion in the vicinity including the welds 16, 17, 18 gradually decreases toward the distal end. Therefore, the guide wire 1 includes the second wire 3 and the fourth wire 6, the first wire 2 and the fourth wire 6, and the first wire 2 and the third wire 5 made of materials having different elastic moduli. Even in the vicinity of the part including the welded parts 16, 17, and 18 connected (joined), the rigidity changes more gently (smoothly) along the longitudinal direction. As a result, the kink resistance (bending resistance) in the vicinity of the welds 16, 17, and 18 is further improved, and the guide wire 1 can obtain more excellent operability.

  In the present embodiment, the outer diameter gradually decreasing portion 15 has a tapered shape in which the outer diameter continuously decreases at a substantially constant decrease rate in the distal direction. In other words, the taper angle of the outer diameter gradually decreasing portion 15 is substantially constant along the longitudinal direction. Thereby, in the guide wire 1 of this embodiment, the rigidity change along the longitudinal direction can be made more gradual (smooth) particularly in the vicinity of the portion including the welded portions 17 and 18.

  The length of the outer diameter gradually decreasing portion 15 is not particularly limited, but is preferably about 10 to 1000 mm, and more preferably about 20 to 300 mm.

  The outer diameter gradually decreasing portion 15 differs from the illustrated configuration in that the outer diameter decreasing rate (taper angle of the outer diameter gradually decreasing portion 15) in the distal direction of the outer diameter gradually decreasing portion 15 varies along the longitudinal direction. For example, a portion where the outer diameter reduction rate is relatively large and a relatively small portion may be alternately formed a plurality of times. In this case, there may be a portion where the decrease rate of the outer diameter toward the distal end of the outer diameter gradually decreasing portion 15 becomes zero.

  Further, the distal end 152 of the outer diameter gradually decreasing portion 15 is the position of the distal end of the third wire 5, but is not limited to such a configuration, and the distal end 152 of the outer diameter gradually decreasing portion 15 is in the longitudinal direction of the third wire 5. An intermediate position or an intermediate position of the first wire 2 may be used. That is, the outer diameters of the third wire 5 and the first wire 2 on the tip side do not have to be gradually reduced toward the tip.

  In addition, the base end 151 of the outer diameter gradually decreasing portion 15 is a position in the middle of the second wire 3 in the longitudinal direction, a position in the middle of the first wire 2 in the longitudinal direction, or a position in the middle of the third wire 5 in the longitudinal direction. There may be.

  Hereinafter, with reference to FIG. 2, the procedure in the case of joining each wire by butt seam welding which is an example of butt resistance welding is demonstrated. In addition, since the method of joining each wire is substantially the same, below, the case where the 2nd wire 3 and the 4th wire 6 are joined by butt seam welding is demonstrated as a representative. In the figure, procedures <1> to <4> in the case where the second wire 3 and the fourth wire 6 are joined by butt seam welding are shown.

  In the procedure <1>, the second wire 3 and the fourth wire 6 fixed (attached) to a butt welder (not shown) are shown.

  In procedure <2>, the second wire 3 and the fourth wire 6 are connected to the proximal end side connection end surface 52 of the fourth wire 6 and the distal end of the second wire 3 while a predetermined voltage is applied by a butt welder. The contact end surface 31 on the side is brought into pressure contact. By this pressure contact, a molten layer is formed in the contact portion, and the second wire 3 and the fourth wire 6 are firmly connected.

  In the procedure <3>, the protruding portion of the connection portion (welded portion 16) deformed by the pressure contact is deleted.

  The above steps <1> to <3> are repeated to weld (join) the third wire 5, the first wire 2, the fourth wire 6, and the second wire 3, respectively.

  Next, in the step <4>, the portion including the connection portion (welded portions 17 and 18) is polished to form the outer diameter gradually decreasing portion 15 in which the outer diameter gradually decreases in the distal direction. In the step of welding the wires 2, 3, 5, 6 to each other, if necessary, the procedure <3> may be omitted, and in this procedure <4>, the protruding portion of the joint portion may be deleted, The outer diameter gradually decreasing portion 15 may be formed.

  As shown in this embodiment, the first wire 2 and the fourth wire 6 and the third wire 5 and the first wire 2 are preferably joined by welding, but any other method is used. You can also

  FIG. 3 and FIG. 4 are diagrams each showing a use state when the guide wire 1 of the present invention is used in PTCA surgery.

  3 and 4, reference numeral 40 denotes an aortic arch, reference numeral 50 denotes a right coronary artery of the heart, reference numeral 60 denotes a right coronary artery opening, and reference numeral 70 denotes a vascular stenosis. Reference numeral 30 is a guiding catheter for reliably guiding the guide wire 1 from the femoral artery to the right coronary artery, and reference numeral 20 is a balloon catheter for constriction portion expansion having a balloon 201 that can be expanded and contracted at its distal end. .

  As shown in FIG. 3, the distal end of the guide wire 1 is projected from the distal end of the guiding catheter 30 and inserted into the right coronary artery 50 through the right coronary artery opening 60. Further, the guide wire 1 is advanced and inserted into the right coronary artery from the distal end, and stopped at a position where the distal end exceeds the vascular stenosis 70. Thereby, the passage of the balloon catheter 20 is secured. At this time, the welds 16, 17, and 18 of the guide wire 1 are all located in the aortic arch 40 or in the vicinity thereof (in vivo).

  Next, as shown in FIG. 4, the distal end of the balloon catheter 20 inserted from the proximal end side of the guide wire 1 is projected from the distal end of the guiding catheter 30 and further advanced along the guide wire 1 to open the right coronary artery opening. It is inserted into the right coronary artery 50 from the part 60 and stops when the balloon reaches the position of the vascular stenosis part 70.

  Next, a balloon expansion fluid is injected from the proximal end side of the balloon catheter 20 to expand the balloon 201 and expand the vascular stenosis part 70. By doing in this way, deposits, such as cholesterol deposited on the blood vessel of the blood vessel stenosis part 70, are physically expanded, and blood flow obstruction can be eliminated.

Second Embodiment
Next, a second embodiment of the guide wire of the present invention will be described.

  FIG. 5 is a longitudinal sectional view showing a second embodiment of the guide wire of the present invention. For convenience of explanation, the right side in FIG. 5 is referred to as “base end”, and the left side is referred to as “tip”. Further, in FIG. 5, for the sake of easy understanding, the length direction of the guide wire is shortened, the thickness direction of the guide wire is exaggerated, and the ratio between the length direction and the thickness direction is schematically illustrated. It is very different from the actual one.

  In the following, the guide wire 1 ′ shown in FIG. 5 will be described. The description will focus on the differences from the guide wire 1 of the first embodiment, and the description of the same matters will be omitted.

  The guide wire 1 ′ of the present embodiment is the same as the guide wire 1 of the first embodiment except that the fourth wire is omitted.

  That is, in the guide wire 1 ′ of the present embodiment, the third wire 5 ′ is disposed on the distal end side of the first wire 2, and the third wire 5 ′, the first wire 2, the first wire 2, and the second wire are connected. These are connected to each other by welding.

  The constituent material of the first wire 2 is the same as that of the first wire 2 in the first embodiment. That is, the constituent material of the first wire 2 is preferably an alloy (including a superelastic alloy) exhibiting pseudoelasticity, and more preferably a superelastic alloy.

  On the other hand, the constituent material of the third wire 5 'is the same as that of the third wire 5 in the first embodiment. That is, a nickel-based alloy (Ni-based alloy mainly composed of Ni) can be used as the constituent material of the third wire 5 '.

  The first wire 2 is made of a material whose weldability to the third wire 5 ′ is substantially equal to or higher than the weldability of the second wire 3 to the first wire 2. Thereby, higher joint strength is obtained at the welded portion 17 ′ between the third wire 5 ′ and the first wire 2. It should be noted that sufficient bonding strength is also obtained at the welded portion 14 between the first wire 2 and the second wire 3, and thus the guide wire 1 ′ has excellent operability.

  In the present embodiment, the connection end surface 51 ′ of the third wire 5 ′ with respect to the first wire 2 and the connection end surface 21 of the first wire 2 with respect to the third wire 5 ′ are both in the axial direction (longitudinal direction) of the guide wire 1. However, the processing for forming the connection end faces 21 and 51 ′ is extremely easy, and the above effect can be obtained without complicating the manufacturing process of the guide wire 1 ′. Can be achieved.

  Note that, unlike the configuration shown in the drawing, each of the connection end faces 21, 51 ′ may be inclined with respect to a plane perpendicular to the axial direction (longitudinal direction) of the guide wire 1 ′, and may be a concave surface or a convex surface. Also good.

  Such a third wire 5 ′ can be provided for any purpose. For example, the third wire 5 ′ is provided for the purpose of ensuring the reshapability of the distal end portion of the guide wire 1 ′.

  In this case, the constituent material of the third wire 5 ′ is a Ni-based alloy (nickel-based alloy) mainly composed of Ni so that the desired shape can be formed and the shape can be maintained. ) Is used. By configuring the third wire 5 ′ with a nickel-based alloy, particularly excellent reshapability is exhibited. Moreover, when the 1st wire 2 is comprised with a Ni-Ti type-alloy, the joining property by welding with the 1st wire 2 of 3rd wire 5 'is further improved.

  The length of the third wire 5 'is not particularly limited, but is preferably about 20 to 1000 mm.

  The welded portion 17 ′ is located between the base end 151 of the outer diameter gradually decreasing portion 15 and the distal end 152 of the outer diameter gradually decreasing portion 15 (in the middle of the outer diameter gradually decreasing portion 15). The three wires 5 ′ have a tapered shape in which the outer diameter continuously decreases gradually toward the distal end over almost the entire length. Although the elastic modulus of the constituent material of the third wire 5 ′ as described above is larger than the elastic modulus of the constituent material of the first wire 2, the guide wire can be obtained by configuring the third wire 5 ′ as illustrated. It is possible to prevent the rigidity of the tip portion of 1 ′ from becoming extremely large.

  Note that the taper angle of the tapered portion of the third wire 5 ′ may be constant along the longitudinal direction or may vary along the longitudinal direction.

  In addition, the third wire 5 ′ may have a portion having a constant outer diameter along the longitudinal direction, unlike the third wire 5 ′. For example, the third wire 5 ′ has a tapered portion whose outer diameter gradually decreases in the distal direction, formed at a plurality of locations along the longitudinal direction, and the outer diameter is between the tapered portion and the tapered portion. A certain part may be formed along the longitudinal direction. Even in such a case, the same effect as described above can be obtained. In addition, the third wire 5 ′ may have a constant outer diameter along the longitudinal direction at the tip side, unlike the figure.

  As shown in the present embodiment, the first wire 2 and the second wire 3 are preferably joined by welding, but any other method can be used.

  Such a guide wire 1 'can also be used in the same manner as the guide wire 1 of the first embodiment.

  The guide wire of the present invention has been described above with respect to each illustrated embodiment. However, the present invention is not limited to this, and each part constituting the guide wire has an arbitrary configuration that can exhibit the same function. Can be substituted for Moreover, arbitrary components may be added.

DESCRIPTION OF SYMBOLS 1 Guide wire 2 1st wire 21 Connection end surface 22 Connection end surface 3 2nd wire 31 Connection end surface 4 Coil 5 3rd wire 51 Connection end surface 52 Connection end surface 6 4th wire 61 Connection end surface 11, 12, 13 Fixing material 16, 17, 18 welded portion 15 outer diameter gradually decreasing portion 151 proximal end of outer diameter gradually decreasing portion 152 distal end of outer diameter gradually decreasing portion 1 'guide wire 5' third wire 51 'connection end surface 14, 17' welded portion 20 balloon catheter 201 balloon 30 guiding Catheter 40 Aortic arch 50 Right coronary artery 60 Right coronary artery opening 70 Blood vessel stenosis

Claims (5)

A linear first wire disposed on the distal end side and made of a Ni-Ti alloy;
A linear second wire that is disposed on the proximal end side of the first wire and is made of a material having a larger elastic modulus than the constituent material of the first wire;
A linear third wire arranged on the tip side of the first wire and made of a Ni-based alloy mainly composed of Ni;
The guide wire, wherein the first wire and the third wire are connected by welding.   The guide wire according to claim 1, wherein the third wire is disposed so as to extend the first wire toward a distal end side.   The guide wire according to claim 1 or 2, wherein a distal end of the first wire and a proximal end of the third wire are connected by welding.   The guide wire according to any one of claims 1 to 3, wherein the second wire is made of stainless steel or a cobalt-based alloy.   The guide wire according to any one of claims 1 to 4, wherein the Ni-based alloy is a Ni-Cr-based alloy or a Ni-Co-based alloy.

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