JP3962652B2 - Guide wire - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
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.
[0002]
[Prior art]
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.
[0003]
The blood vessel is intricately curved, and the guide wire used to insert the balloon catheter into the blood vessel has moderate flexibility, pushability and torque transmission for transmitting operation at the proximal end to the distal side ( These are collectively referred to as “operability”), and further kink resistance (bending resistance) is required. In order to satisfy such requirements, a superelastic alloy such as a Ni-Ti alloy is preferably used as a constituent material of the core material (wire body) of the guide wire in order to impart flexibility and restorability.
[0004]
By the way, in such a guide wire, in order to select a blood vessel branch, a doctor often uses the guide wire by bending the distal end portion into a desired shape. Bending the distal end portion of the guide wire into a desired shape in this way is called reshaping.
[0005]
However, when the wire body is made of a superelastic alloy such as a Ni—Ti alloy, reshaping is difficult because the wire body exhibits superelasticity. Therefore, it is necessary to separately provide a reshape ribbon made of a reshapeable material (for example, stainless steel). However, if the wire body is a Ni-Ti alloy, the solder wettability is poor and the solder joint strength is low. In order to increase the solder joint strength, contact with air after removing the oxide film on the metal surface A special treatment of covering the preliminary tin with the shielded material must be performed, and much labor and time are required for the production.
[0006]
[Problems to be solved by the invention]
An object of the present invention is to provide a guide wire that has a simple structure, is excellent in operability, and can easily and reliably reshape (shape) a distal end portion of the guide wire.
[0007]
[Means for Solving the Problems]
  Such an object is achieved by the present inventions (1) to (6) below. In addition, the following (7) ~(21)Is preferred.
[0008]
  (1) a linear first wire made of a reshapeable metal material disposed on the tip side;
  A linear second wire that is arranged on the base end side of the first wire and is made of an alloy exhibiting pseudoelasticity;
The first wire has a small cross-sectional area portion in the vicinity of a welded portion between the first wire and the second wire, whose cross-sectional area is smaller than the cross-sectional area of the tip end portion of the second wire,
  The guide wire, wherein the first wire and the second wire are connected by welding.
[0009]
(2) The guide wire according to (1), further including a step filling member that fills a step formed on an outer periphery of the small cross-sectional area portion.
[0010]
(3) The guide wire according to (2), wherein the step filling member is made of a flexible material that contributes little to the rigidity of the guide wire.
[0011]
  (4) A linear third wire that is disposed on the base end side of the second wire and is made of a material having a larger elastic modulus than that of the constituent material of the second wire, and the second wire and the third wire are provided. And the above (1) One of (3)Guide wire as described in.
[0012]
  (5) The first wire has an overlapping portion in which the proximal end portion of the first wire and the distal end portion of the second wire overlap each other along the axial direction of the two wires, and the first portion includes the first portion. The above (the wire and the second wire are welded)1) One of (4)Guide wire as described in.
[0013]
  (6) Stiffening is provided in the vicinity of the proximal end of the welded portion between the first wire and the second wire so as to cover the outer periphery of the second wire and to increase the bending rigidity in the vicinity of the distal end portion of the second wire. The above having a member (1) One of (4)Guide wire as described in.
[0014]
(7) The guide wire according to any one of (1) to (6), wherein the second wire is made of stainless steel.
[0015]
(8) The connection end surface between the first wire and the second wire is substantially perpendicular to the axial direction of both wires, respectively, according to any one of (1) to (4) and (6). Guide wire.
[0016]
(9) The guide wire according to any one of (1) to (8), wherein the guide wire includes a spiral coil that covers at least a portion on a distal end side of the first wire.
[0017]
(10) The guide wire according to (9), wherein a welded portion between the first wire and the second wire is located closer to the proximal end than the proximal end of the coil.
[0018]
(11) The guide wire according to (9), wherein a weld portion between the first wire and the second wire is located on a distal end side with respect to a proximal end of the coil.
[0019]
(12) The guide wire according to any one of the above (1) to (11), which is used so that a welded portion between the first wire and the second wire is located in a living body.
[0020]
  (13) The third wire is made of stainless steel or a cobalt alloy.(4)Guide wire as described in.
[0021]
(14) The guide wire according to any one of (1) to (13), wherein the welding is performed by butt resistance welding.
[0022]
  (15) The bending rigidity at the distal end of the second wire is substantially equal to the bending rigidity at the proximal end of the first wire.One of (1) to (14)Guide wire as described in.
[0024]
  (16)  The said overlapping part is a guide wire as described in said (5) which has a part in which the ratio which the said 2nd wire occupies in the cross-sectional area of the said overlapping part reduces gradually toward a front-end | tip direction.
[0025]
  (17)  The base end portion of the first wire has a cone shape or a frustum shape whose outer diameter gradually decreases toward the base end direction,
  The distal end portion of the second wire has a conical or frustum-shaped hollow portion whose inner diameter gradually decreases in the proximal direction,
  The first wire and the second wire are welded in a state where the proximal end portion of the first wire is inserted into the hollow portion (5) or(16)Guide wire as described in.
[0026]
  (18)  The distal end portion of the second wire has a conical shape or a truncated cone shape whose outer diameter gradually decreases in the distal direction,
  The proximal end portion of the first wire has a conical or frustum-shaped hollow portion whose inner diameter gradually decreases in the distal direction,
  The first wire and the second wire are welded in a state where the tip of the second wire is inserted into the hollow portion (5) or(16)Guide wire as described in.
[0027]
  (19)  The guide wire according to (6), wherein the rigidity imparting member is made of a material having a larger elastic modulus than the constituent material of the second wire.
[0028]
  (20)  The rigidity imparting member is a tubular or coiled member (6) or(19)Guide wire as described in.
[0029]
  (21)  Said (1) thru | or which has a coating layer which consists of a resin material which covers the outer periphery of at least one part of said 1st wire and said 2nd wire(20)A guide wire according to any one of the above.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the guide wire of the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.
[0031]
<First Embodiment>
FIG. 1 is a longitudinal sectional view showing an embodiment of the guide wire of the present invention, and FIG. 2 is a diagram showing a procedure for connecting the first wire and the second wire 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.
[0032]
A guide wire 1 </ b> A shown in FIG. 1 is a catheter guide wire used by being inserted into a catheter, and has a wire body 10 and a spiral coil 4. The total length of the guide wire 1A (wire body 10) is not particularly limited, but is preferably about 200 to 5000 mm. Further, the outer diameter of the guide wire 1A is not particularly limited, but it is usually preferably about 0.2 to 1.2 mm.
[0033]
The wire body 10 includes a first wire 2 disposed on the distal end side, a second wire 3 disposed on the proximal end side of the first wire 2, and a third wire disposed on the proximal end side of the second wire 3. 5 is connected.
[0034]
The portion on the distal end side of the wire body 10 is an outer diameter gradually decreasing portion 15 whose outer diameter gradually decreases in the distal direction. Thereby, the rigidity (bending rigidity, torsional rigidity) of the wire main body 10 can be gradually decreased toward the distal end direction. As a result, the guide wire 1A obtains good flexibility at the distal end portion, and enters the blood vessel. Follow-up performance and safety are improved.
[0035]
In the present embodiment, the outer diameter gradually decreasing portion 15 is formed from the distal end portion of the third wire 5 to the distal end of the first wire 2. 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 decreasing rate toward the distal direction. In other words, the taper angle of the outer diameter gradually decreasing portion 15 is substantially constant along the longitudinal direction. In addition, unlike such a configuration, the rate of decrease of the outer diameter toward the distal end direction of the outer diameter gradually decreasing portion 15 (taper angle of the outer diameter gradually decreasing portion 15) may change along the longitudinal direction, For example, a portion where the reduction rate of the outer diameter is relatively large and a portion where the outer diameter is relatively small 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.
[0036]
The first wire 2 is a wire made of a metal material, having elasticity, and capable of being reshaped (shaped). Since the guide wire 1A has the first wire 2 at the distal end portion thereof, when the doctor or the like bends the distal end portion of the guide wire 1A into a desired shape with fingers, the first wire 2 is plastically deformed. The desired shape can be maintained.
[0037]
In the present invention, by providing the first wire 2, it is possible to reshape the distal end portion of the guide wire 1A with a simple structure without providing a separate member such as a reshape ribbon. Further, the manufacturing is easy, and the manufacturing cost can be reduced.
[0038]
The constituent material (material) of the first wire 2 is not particularly limited as long as it can be reshaped. Stainless steel (for example, SUS304, SUS303, SUS316, SUS316L, SUS316J1, SUS316J1L, SUS405, SUS430, SUS434, SUS444, SUS429) SUS430F, all types of SUS such as SUS302), various kinds of metal materials such as piano wire and cobalt-based alloy can be used, but stainless steel is preferable. By configuring the first wire 2 of stainless steel, the guide wire 1A can be more easily reshaped at the distal end portion, and can maintain the reshaped shape firmly.
[0039]
Although the length of the 1st wire 2 is not specifically limited, Usually, it is preferable that it is about 10-1000 mm, and especially the length of the 2nd wire 2 is about 10-50 mm or about 100-300 mm. Is more preferable.
[0040]
When the length of the first wire 2 is relatively short, such as about 10 to 50 mm, it is possible to reshape the guide wire 1A that needs to be reshaped, and near the tip of the guide wire 1A excluding the most distal portion. Since this part is composed of the second wire 3 made of a pseudoelastic alloy, which will be described later, the part has high flexibility, excellent followability to a complicatedly curved blood vessel, and bends to the part. There is no wrinkle, and the influence on the operability due to the bending wrinkle can be prevented.
[0041]
Further, when the length of the first wire 2 is relatively long, such as about 100 to 300 mm, almost the entire portion that protrudes (exposes) from the distal end opening of the catheter used together with the guide wire 1A and enters the blood vessel is relatively long. Since it is composed of the first wire 2 made of a material having a high elastic modulus, the portion has high rigidity (bending rigidity, torsional rigidity), and torque transmission and pushability for transmitting the operation at the proximal end to the distal end side. And improved operability can be obtained.
[0042]
The distal end portion of the second wire 3 is connected (connected) to the proximal end portion of the first wire 2. 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.
[0043]
The second wire 3 is made of an alloy exhibiting pseudoelasticity (hereinafter referred to as “pseudoelastic alloy”). Thereby, the portion of the second wire 3 in the guide wire 1 </ b> A is relatively flexible, has a restoring property, and is difficult to bend. Therefore, the guide wire 1A can be reshaped at the distal end portion, while the second wire 3 portion can have excellent followability to a blood vessel that is curved in a complicated manner and bends during use. Therefore, it is possible to reliably prevent the operability from being lowered. For this reason, the guide wire 1A can obtain excellent operability.
[0044]
Pseudoelastic alloys include those in which the stress-strain curve by tension is any shape, including those in which transformation points such as As, Af, Ms, and Mf can be remarkably measured, and those that cannot be measured, and are greatly increased by stress. Anything that is deformed (distorted) and returns almost to its original shape by removing the stress is included. Superelastic alloys are also included in pseudoelastic alloys. The second wire 3 is preferably made of a superelastic alloy.
[0045]
An example of the composition of the pseudoelastic alloy is a Ni—Ti alloy such as a Ni—Ti alloy of 49 to 52 atomic% Ni. Moreover, as an example of the composition of the superelastic alloy as a preferable constituent material, in addition to the above-described Ni—Ti alloy, a Cu—Zn alloy of 38.5 to 41.5 wt% Zn, 1 to 10 wt% X Cu-Zn-X alloys (X is at least one of Be, Si, Sn, Al, and Ga), Ni-Al alloys of 36 to 38 atomic% Al, and the like. Of these, the Ni-Ti alloy is particularly preferable as the superelastic alloy.
[0046]
In this guide wire 1A, the first wire 2 and the second wire 3 are connected (fixed) to each other by welding. As a result, the welded portion (connecting portion) 14 between the first wire 2 and the second wire 3 has a high bonding strength (joining strength), and thus the guide wire 1A is able to obtain a torsional torque from the second wire 3 and The pushing force is reliably transmitted to the first wire 2.
[0047]
In this embodiment, the connection end surface 21 of the first wire 2 with respect to the second wire 3 and the connection end surface 31 of the second wire 3 with respect to the first wire 2 are substantially perpendicular to the axial direction (longitudinal direction) of both wires. It is flat. Thereby, the process for forming the connection end surfaces 21 and 31 is very easy, and the above-described effects can be achieved without complicating the manufacturing process of the guide wire 1A.
[0048]
Note that, unlike the illustrated configuration, the connection end faces 21 and 31 may be inclined with respect to a plane perpendicular to the axial direction (longitudinal direction) of both wires, or may be concave or convex.
[0049]
The method for welding the first wire 2 and the second wire 3 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, as for the welding part 14, higher bond strength is obtained.
[0050]
Hereinafter, with reference to FIG. 2, the procedure in the case of joining the 1st wire 2 and the 2nd wire 3 by butt seam welding which is an example of butt resistance welding is demonstrated. In the figure, procedures (1) to (4) in the case of joining the first wire 2 and the second wire 3 by butt seam welding are shown.
[0051]
In the procedure (1), the first wire 2 and the second wire 3 fixed (attached) to a butt welder (not shown) are shown.
[0052]
In step (2), the first wire 2 and the second wire 3 are connected to the proximal end side connection end surface 21 of the first wire 2 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 at the contact portion, and the first wire 2 and the second wire 3 are firmly connected.
[0053]
In step {circle around (3)}, the protruding portion of the connection portion (welded portion 14) deformed by the pressure contact is deleted.
[0054]
Next, in step {circle around (4)}, the portion including the connection portion (welded portion 14) is polished to form the outer diameter gradually decreasing portion 15 in which the outer diameter gradually decreases in the distal direction. The procedure (4) may be performed by omitting the procedure (3).
[0055]
As shown in FIG. 1, the distal end portion of the third wire 5 is connected (connected) to the proximal end portion of the second wire 3. The third wire 5 is an elastic wire. Although the length of the 3rd wire 5 is not specifically limited, It is preferable that it is about 100-4500 mm.
[0056]
The third wire 5 is made of a material having a higher elastic modulus (Young's modulus (longitudinal elastic modulus), rigidity (transverse elastic modulus), volume elastic modulus) than the constituent material of the second wire 3. In the present embodiment, by providing such a third wire 5, in the portion of the second wire 3, while obtaining excellent flexibility (following ability to blood vessels) and difficulty in bending bends, In the portion of the third wire 5 on the base end side, appropriate rigidity (bending rigidity, torsional rigidity) is obtained. Therefore, the guide wire 1A becomes so-called firm and the pushability and torque transmission performance are improved, so that more excellent insertion operability can be obtained.
[0057]
The constituent material (raw material) of the third wire 5 is not particularly limited as long as it has an elastic modulus larger than that of the constituent material of the second wire 3, but is preferably stainless steel or a cobalt-based alloy. Thereby, the guide wire 1A can obtain more excellent pushability and torque transmission.
[0058]
The third wire 5 and the second wire 3 are connected (fixed) to each other by welding. Thereby, the welding part 16 of the 3rd wire 5 and the 2nd wire 3 has high joint strength (joining strength), and the effect similar to having described the welding part 14 is acquired. Matters such as a preferable welding method for the welded portion 16 are the same as those for the welded portion 14.
[0059]
The coil 4 is installed so as to cover a portion on the distal end side of the wire body 10. The coil 4 is a member formed by spirally winding a wire (thin wire). In the configuration shown in the figure, the wire body 10 is inserted through substantially the center of the inside of the coil 4, and 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.
[0060]
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, tungsten, and alloys containing these. In particular, when it is made of an X-ray opaque material such as a noble metal, X-ray contrast can be obtained in the guide wire 1A, and it 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 composed of a coil made of an X-ray-impermeable material, and the proximal end side may be composed of 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.
[0061]
The proximal end portion and the distal end portion of the coil 4 are fixed to the wire body 10 by fixing materials 11 and 12, respectively. Further, an intermediate portion (position near the tip) of the coil 4 is fixed to the wire body 10 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 may be welding, for example. 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.
[0062]
In the present embodiment, since such a coil 4 is provided, the tip side portion of the wire body 10 is covered with the coil 4 and has a small contact area, so that the sliding resistance of the guide wire 1A is reduced. Therefore, the operability of the guide wire 1A is further improved.
[0063]
In the present embodiment, the welded portion 14 is located on the distal end side from the proximal end of the coil 4. In other words, the coil 4 is installed so as to cover the entire first wire 2 and the tip side portion of the second wire 3. The portion where the coil 4 covers the wire body 10 can be made relatively long, and as a result, the sliding resistance of the guide wire 1A can be further reduced.
[0064]
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.
[0065]
In such a guide wire 1A of the present embodiment, the outer diameters of the second wire 3 and the first wire 2 extend from the position on the proximal end side to the welding portion 14 to the position on the distal end side from the welding portion 14. Until, it gradually decreases toward the tip. In other words, the taper in which the outer diameter of the portion from the position on the proximal end side of the welding portion 14 of the wire body 10 to the position on the distal end side from the welding portion 14 is gradually narrowed toward the distal end. It has a shape. Thereby, the rigidity (bending rigidity, torsional rigidity) of the vicinity of the part including the welded portion 14 gradually decreases in the distal direction. Therefore, the guide wire 1 </ b> A is made of different materials and includes a welded portion 14 in which the first wire 2 and the second wire 3 having different rigidity are connected (joined) along the longitudinal direction. Therefore, the rigidity changes gently (smooth). As a result, the kink resistance (bending resistance) in the vicinity of the welded portion 14 is improved, and the guide wire 1A can obtain more excellent operability.
[0066]
Furthermore, in the present embodiment, the portion from the position on the proximal end side of the welded portion 16 of the wire body 10 to the position on the distal end side of the welded portion 16 across the welded portion 16 is similarly outer diameter toward the distal end direction. Has a tapered shape that gradually becomes thinner. As a result, the kink resistance (bending resistance) in the vicinity of the welded portion 16 is improved, and the guide wire 1A can obtain more excellent operability.
[0067]
All or a part of the outer peripheral surface of the guide wire 1A may be subjected to a process for suppressing friction generated by contact with the inner wall of the catheter used together with the guide wire 1A. Thereby, the friction with the inner wall of the catheter is suppressed, and the operability of the guide wire 1A in the catheter becomes better. 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 1A.
[0068]
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.
[0069]
FIG. 3 and FIG. 4 are diagrams each showing a use state when the guide wire of the present invention is used in PTCA surgery.
[0070]
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 1A 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. .
[0071]
As shown in FIG. 3, the distal end of the guide wire 1 </ b> A protrudes from the distal end of the guiding catheter 30 and is inserted into the right coronary artery 50 through the right coronary artery opening 60. Further, the guide wire 1A is advanced and inserted into the right coronary artery from the distal end. At this time, the distal end portion of the guide wire 1A is reshaped into a desired shape and inserted in advance so that the blood vessel branch leading to the blood vessel stenosis portion 70 can be easily selected and inserted. The blood vessel branch is selected and stopped at a position where the tip exceeds the blood vessel stenosis part 70. Thereby, the passage of the balloon catheter 20 is secured. At this time, the welded portion 14 and the welded portion 16 of the guide wire 1A are located at positions (in vivo) as shown in FIG.
[0072]
Next, as shown in FIG. 4, the distal end of the balloon catheter 20 inserted from the proximal end side of the guide wire 1A is projected from the distal end of the guiding catheter 30, and further advanced along the guide wire 1A 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.
[0073]
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.
[0074]
Second Embodiment
FIG. 5 is a longitudinal sectional view showing a second embodiment of the guide wire of the present invention. Hereinafter, the second embodiment of the guide wire according to the present invention will be described with reference to this figure, but the description will focus on the differences from the above-described embodiment, and the description of the same matters will be omitted.
[0075]
The guide wire 1B of this embodiment is the same as that of the first embodiment except that it has a plastic jacket (covering layer) 17 made of synthetic resin that covers the outer peripheral surface (outer surface).
[0076]
In the present embodiment, the plastic jacket 17 is provided so as to cover almost the entire outer peripheral surface of the guide wire 1B. The plastic jacket 17 covers the surface of the smooth welded portion 16. Examples of the constituent material of the plastic jacket 17 include polyethylene, polyvinyl chloride, polyester, polypropylene, polyamide, polyurethane, polystyrene, polycarbonate, silicone resin, fluororesin (PTFE, ETFE, etc.), various other elastomers, Alternatively, these composite materials are preferably used.
[0077]
By providing such a plastic jacket 17, the friction with the inner wall of the catheter used together with the guide wire 1B is reduced and the slidability is improved, and the operability of the guide wire 1B in the catheter is further improved. It will be good.
[0078]
When such a plastic jacket 17 is provided, the plastic jacket 17 may not be provided on the entire guide wire 1B. For example, the plastic jacket 17 is provided only on the distal end side portion (particularly, the outer diameter gradually decreasing portion 15) of the guide wire 1B. It may be done. Further, a plastic jacket 17 may be provided in a portion excluding the outer periphery of the coil 4. Further, when the plastic jacket 17 is provided, excellent slidability can be obtained without the coil 4, and therefore the coil 4 may be omitted.
[0079]
<Third Embodiment>
FIG. 6 is a longitudinal sectional view showing a third embodiment of the guide wire of the present invention. Hereinafter, the third embodiment of the guide wire of the present invention will be described with reference to this figure. However, the difference from the first embodiment will be mainly described, and the description of the same matters will be omitted.
[0080]
The wire body 10 in the guide wire 1 </ b> C of the present embodiment includes the first wire 2 and the second wire 3, and does not have the third wire 5. Thereby, in this embodiment, since the whole part of the base end side from the welding part 14 is comprised with the 2nd wire 3 which consists of a pseudoelastic alloy, Preferably it is a superelastic alloy, in the whole of the said part, it was excellent in flexibility. And it is possible to prevent the operability from being deteriorated due to bending folds during use. Operability is obtained. In particular, during use, the proximal end portion of the guide wire 1C, which is a portion that the operator moves out of the body and is operated by the hand, is not bent and has no wrinkles, so that this portion is easy to grasp and operate. easy.
[0081]
In the present embodiment, the welded portion 14 is located closer to the proximal end than the proximal end of the coil 4. That is, the entire coil 4 is fixed (bonded) to the first wire 2 including the fixing material 11 (solder) for fixing the base end portion thereof. This eliminates the need to fix (join) a part of the coil 4 to the second wire 3 made of a superelastic alloy such as a Ni—Ti alloy having poor solder wettability, so that the coil 4 can be easily fixed (joined). In addition to being easy to manufacture, the coil 4 can be more firmly fixed.
[0082]
In the present embodiment, similarly to the first embodiment, the outer diameter of the wire body 10 (the second wire 3 and the first wire 2) straddles the welded portion 14 from the position on the proximal end side with respect to the welded portion 14. Thus, it gradually decreases toward the tip from the welded portion 14 to the tip side. That is, the vicinity of the region including the welded portion 14 has a tapered shape in which the outer diameter gradually decreases toward the tip. As a result, the guide wire 1 </ b> C changes gradually (smoothly) along the longitudinal direction even in the vicinity thereof including the welded portion 14, and kink resistance (bending resistance) in the vicinity of the welded portion 14. And improved operability can be obtained.
[0083]
The guide wire 1C of the present embodiment may have a plastic jacket as in the second embodiment.
[0084]
<Fourth embodiment>
FIG. 7 is a longitudinal sectional view showing a fourth embodiment of the guide wire of the present invention. Hereinafter, the fourth embodiment of the guide wire according to the present invention will be described with reference to this figure. However, the difference from the third embodiment will be mainly described, and the description of the same matters will be omitted.
[0085]
The first wire 2 in the guide wire 1 </ b> D of the present embodiment has a small cross-sectional area portion 22 in the vicinity of the weld portion 14 whose cross-sectional area is smaller than the cross-sectional area of the distal end portion 32 of the second wire 3. In other words, in the first wire 2, the cross-sectional area of the portion (small cross-sectional area portion 22) from the connection end surface 21 to a predetermined position on the front end side is smaller than the cross-sectional area of the front end portion 32 of the second wire 3. ing. In the present embodiment, the small cross-sectional area portion 22 has an outer diameter smaller than the outer diameter of the distal end portion 32 of the second wire 3, so that the cross-sectional area is smaller than the cross-sectional area of the distal end portion 32. . That is, the area of the connection end surface 21 is smaller than the area of the connection end surface 31.
[0086]
As described above, since the second wire 3 is made of a relatively soft material (low elastic modulus), for example, a superelastic alloy, the outer diameter of the proximal end portion of the first wire 2 and the second wire 3, the rigidity of the proximal end portion of the first wire 2 is larger than the rigidity of the distal end portion 32 of the second wire 3, but in the present embodiment, the first wire 2 has the same outer diameter. By providing a small cross-sectional area portion 22 at the base end portion and reducing (decreasing) the rigidity (bending rigidity, torsional rigidity) in the small cross-sectional area portion 22, Changes along the longitudinal direction of rigidity (bending rigidity, torsional rigidity) can be made gentle (smooth). As a result, the kink resistance (bending resistance) in the vicinity of the welded portion 14 is improved, and the guide wire 1D can obtain more excellent operability.
[0087]
In the present embodiment, the small cross-sectional area portion 22 includes a portion where the outer diameter of the small cross-sectional area portion 22 gradually decreases toward the proximal direction, that is, a portion where the cross-sectional area gradually decreases toward the proximal direction. Have. Thereby, the rigidity (bending rigidity, torsional rigidity) can be gradually decreased in the direction from the distal end of the small cross-sectional area portion 22 to the base end of the small cross-sectional area portion 22, and as a result, the guide wire 1D. Can make the change along the longitudinal direction of the rigidity (bending rigidity, torsional rigidity) more gradual (smooth).
[0088]
In the configuration shown in the figure, the small cross-sectional area portion 22 has a tapered shape in which the outer diameter (cross-sectional area) gradually decreases toward the proximal direction over the entire length. There may be a portion having a constant outer diameter (cross-sectional area) at the end, and even in that case, the same effect as described above can be obtained.
[0089]
Length of the small cross section area 22 (L in FIG. 1₁Is not particularly limited, but is preferably about 3 to 50 mm, and more preferably about 3 to 10 mm. L₁Is within the above range, the change in rigidity (bending rigidity, torsional rigidity) along the longitudinal direction can be made more gradual (smooth) in the vicinity including the welded portion 14.
[0090]
The small cross-sectional area portion 22 is formed such that the bending rigidity at the base end (connection end face 21) of the first wire 2 is substantially equal to the bending rigidity at the tip end (connection end face 31) of the second wire 3. Is preferred. Thereby, the change of the rigidity along the longitudinal direction can be made more gradual (smooth) in the vicinity thereof including the welded portion 14. The bending rigidity at the proximal end of the first wire 2 is obtained by determining the secondary moment of the section of the connecting end face 21 (determined only from the shape and dimensions of the connecting end face 21).₁And the Young's modulus of the constituent material of the first wire 2 is E₁When E₁I₁The bending rigidity at the distal end of the second wire 3 is obtained by calculating the sectional moment of inertia of the connection end face 31 (determined only from the shape and dimensions of the connection end face 31).₂And the Young's modulus of the constituent material of the second wire 3 is E₂When E₂I₂It is obtained by.
[0091]
Further, the guide wire 1 </ b> D of the present embodiment has a step filling member 6 that fills the step formed on the outer periphery of the welded portion 14. As a result, the step on the outer periphery of the welded portion 14 formed when the outer diameter of the proximal end of the first wire 2 is smaller than the outer diameter of the distal end of the second wire 3 is eliminated. A decrease in slidability can be prevented.
[0092]
In the configuration shown in the figure, the step filling member 6 covers the outer periphery of the small cross-sectional area portion 22, and its outer diameter is substantially constant along the longitudinal direction, and its inner diameter gradually decreases toward the proximal direction. The outer diameter of the guide wire 1D in the vicinity including the welded portion 14 and the small cross-sectional area portion 22 is substantially constant along the longitudinal direction. Thereby, the influence which a level | step difference has on the slidability of guide wire 1D can be eliminated more reliably.
[0093]
The constituent material of the step filling member 6 is not particularly limited. For example, various resin materials and various metal materials can be used, but a relatively flexible material (such as a small contribution to the rigidity of the guide wire 1D). For example, solder, brazing material, epoxy resin, etc.) are preferable. Moreover, the form of the step filling member 6 is not limited to the illustrated configuration, and may be, for example, a coiled member.
[0094]
In this embodiment, the small cross-sectional area portion 22 has a truncated cone shape, but may have a truncated pyramid shape. Further, the configuration of the small cross-sectional area portion 22 is not limited to a configuration in which the outer diameter is reduced to reduce the cross-sectional area, but the small cross-sectional area portion 22 is formed so as to form a cylindrical shape (cylindrical shape) having a hollow portion. It may be formed. In this case, since the small cross-sectional area portion 22 can be formed without reducing the outer diameter, there is an advantage that no step is generated on the outer periphery of the welded portion 14 without providing the step filling member 6.
[0095]
<Fifth Embodiment>
FIG. 8 is a longitudinal sectional view showing a fifth embodiment of the guide wire of the present invention, and FIG. 9 is a view showing a procedure for connecting the first wire and the second wire in the guide wire shown in FIG. Hereinafter, the fifth embodiment of the guide wire of the present invention will be described with reference to these drawings. However, the difference from the third embodiment will be mainly described, and the description of the same matters will be omitted.
[0096]
In the guide wire 1E of the present embodiment, the wire body 10 is in a state in which the proximal end portion 23 of the first wire 2 and the distal end portion 32 of the second wire 3 overlap (coexist) along the axial direction of both wires. The first wire 2 and the second wire 3 are welded (fixed) to each other in the overlapping portion 18. Thereby, since the area (area | region) of the welding part 14 (joining part) can be ensured large, the joint strength of the welding part 14 can be made especially high.
[0097]
In the present embodiment, the proximal end portion 23 of the first wire 2 has a conical shape (or a truncated cone shape) whose outer diameter gradually decreases in the proximal direction, and the distal end portion of the second wire 3. 32 has a hollow portion (recessed portion) 321 that is hollow before being joined to the first wire 2, and the shape of the hollow portion 321 is a conical shape (or a truncated cone having an inner diameter that gradually decreases in the proximal direction). Shape). And when the base end part 23 of the 1st wire 2 inserts in the hollow part 321 of the 2nd wire 3, the overlapping part 18 is formed and both the joint surfaces in this overlapping part 18 are welded. That is, in this embodiment, the welding part 14 is formed so that a conical surface shape may be made.
[0098]
In the illustrated configuration, the outer diameter of the overlapping portion 18 is substantially the same as the portion near the distal end side of the overlapping portion 18 of the first wire 2 and the portion near the proximal end side of the overlapping portion 18 of the second wire 3. It has become. That is, the outer diameter of the wire body 10 is substantially constant in the vicinity thereof including the overlapping portion 18, but unlike the illustration, the outer diameter of the wire body 10 in the vicinity thereof including the overlapping portion 18 is It may change along the longitudinal direction.
[0099]
As described above, since the second wire 3 is made of a relatively soft material (low elastic modulus), for example, a superelastic alloy, when the outer diameters of the two wires 3 are the same, the second wire 3 is used. Is less rigid (bending rigidity, torsional rigidity) than the first wire 2. Since the first wire 2 and the second wire 3 coexist in the overlapping portion 18, the rigidity (bending rigidity, torsional rigidity) of the overlapping portion 18 is the tip side of the overlapping portion 18 of the first wire 2. It has an intermediate size between the rigidity (bending rigidity and torsional rigidity) in the vicinity and the rigidity (bending rigidity and torsional rigidity) in the vicinity of the base end side of the overlapping portion 18 of the second wire 3.
[0100]
As described above, in the guide wire 1E, the overlapping portion 18 having intermediate rigidity between the first wire 2 having relatively high rigidity and the second wire 3 having relatively low rigidity is provided. The change along the longitudinal direction of the rigidity (bending rigidity, torsional rigidity) in the vicinity of the connecting portion between the first wire 2 and the second wire 3 can be made gradual (smooth). As a result, the kink resistance (bending resistance) in the vicinity of the connecting portion between the first wire 2 and the second wire 3 is improved, and the guide wire 1E can obtain more excellent operability.
[0101]
Moreover, in this embodiment, since the base end part 23 of the 1st wire 2 and the front-end | tip part 32 of the 2nd wire 3 overlap in the above forms, and form the overlapping part 18, in the overlapping part 18, The proportion of the second wire 3 in the cross-sectional area of the overlapping portion 18 gradually decreases in the distal direction. In other words, in the overlapping portion 18, the ratio of the first wire 2 in the cross-sectional area of the overlapping portion 18 gradually increases in the distal direction. As a result, the rigidity of the overlapping portion 18 is substantially the same as the rigidity of the second wire 3 at the base end of the overlapping portion 18 and gradually increases from there toward the distal direction. The rigidity of the wire 2 is almost the same. Thereby, the guide wire 1E can make the change along the longitudinal direction of rigidity (bending rigidity, torsional rigidity) more gentle (smooth).
[0102]
In the configuration shown in the figure, the ratio of the second wire 3 in the cross-sectional area over the entire length of the overlapping portion 18 is gradually reduced toward the distal end. If there is, an effect similar to the above can be obtained.
[0103]
Moreover, in this embodiment, since the overlapping part 18 is a form as mentioned above, the bending rigidity of the overlapping part 18 is the same magnitude | size irrespective of the bending direction, and is isotropic. Thereby, the guide wire 1E can obtain more excellent (more natural) operability.
[0104]
The length of the overlapping portion 18 (L in FIG.₂Is not particularly limited, but is preferably about 3 to 100 mm, and more preferably about 5 to 10 mm. L₂Is in the above range, the change in rigidity (bending rigidity, torsional rigidity) along the longitudinal direction of the guide wire 1E can be made more gradual (smooth).
[0105]
Note that the overlapping portion 18 may have a shape having a hemispherical portion.
[0106]
Hereinafter, with reference to FIG. 9, the procedure in the case of joining the 1st wire 2 and the 2nd wire 3 in the guide wire 1E of this embodiment by butt seam welding which is an example of butt resistance welding is demonstrated. In the figure, procedures (1), (2) and (2) 'in the case of joining the first wire 2 and the second wire 3 by butt seam welding are shown.
[0107]
In the procedure (1), the first wire 2 and the second wire 3 fixed (attached) to a butt welder (not shown) are shown. The proximal end portion 23 of the first wire 2 and the distal end portion 32 of the second wire 3 are respectively processed in advance, the proximal end portion 23 is formed in a conical shape, and the distal end portion 32 has a conical hollow portion. 321 is formed.
[0108]
In step {circle around (2)}, the first wire 2 and the second wire 3 are pressed in the axial direction of both wires by a butt welder with the base end portion 23 inserted into the hollow portion 321 of the tip end portion 32. (Pressed) and a predetermined voltage is applied. As a result, a molten layer is formed on the joint surface (contact portion) between the proximal end portion 23 of the first wire 2 and the distal end portion 32 of the second wire 3, and the first wire 2 and the second wire 3 are firmly formed. Connected. If a protruding portion is formed on the outer periphery of the connection portion by this welding, it is removed by polishing or the like.
[0109]
In performing this procedure (2), in this embodiment, since the central axes of the first wire 2 and the second wire 3 coincide with each other only by inserting the base end portion 23 into the hollow portion 321, both of them are aligned. (Center axis alignment) is easy. Further, the proximal end portion 23 and the distal end portion 32 are configured to shift the joining surface between the proximal end portion 23 and the distal end portion 32 when a pressing force is applied to press the overlapping portion 18 in the axial direction of both wires. It is also a shape that prevents an excessive force from acting. Therefore, when a pressing force in the axial direction of both wires is applied to the overlapping portion 18 at the time of welding, it is possible to reliably prevent the joining surface from being displaced (sliding).
[0110]
Further, as shown in the procedure (2), instead of pressing (pressing) the overlapping portion 18 in the axial direction of both wires in the procedure (2), the outer peripheral portion of the overlapping portion 18 is directed toward the inner peripheral side. Alternatively, welding may be performed while pressing. As described above, in this embodiment, the pressing force can be applied to the joint surface between the base end portion 23 and the tip end portion 32 by pressing the overlapping portion 18 from the outer peripheral side to the inner peripheral side. Can be manufactured easily. Note that the pressing methods (2) and (2) 'may be used in combination.
[0111]
The base end portion 23 of the first wire 2 may have a pyramid shape (or a truncated pyramid shape) such as a triangular pyramid, a quadrangular pyramid, a pentagonal pyramid, or a hexagonal pyramid, and the distal end portion of the second wire 3. The 32 hollow portions 321 may have a pyramid shape (or a truncated pyramid shape) corresponding thereto. Further, the overlapping portion 18 has a conical or frustum shape in which the outer diameter of the second wire 3 gradually decreases in the distal direction, contrary to the illustrated configuration, and the proximal end portion of the first wire 2. However, it has a conical or frustum-shaped hollow portion whose inner diameter gradually decreases in the distal direction, and the distal end portion of the second wire 3 is inserted into the hollow portion of the proximal end portion of the first wire 2. It may be.
[0112]
In addition, the configuration of the overlapping portion 18 is not limited to that illustrated in the figure. For example, the proximal end portion 23 of the first wire 2 and the distal end portion 32 of the second wire 3 each have a semi-cylindrical shape. The overlapping portion 18 may be configured by overlapping.
[0113]
<Sixth Embodiment>
FIG. 10 is a longitudinal sectional view showing a sixth embodiment of the guide wire of the present invention. Hereinafter, the sixth embodiment of the guide wire of the present invention will be described with reference to this drawing. However, the difference from the third embodiment will be mainly described, and the description of the same matters will be omitted.
[0114]
The guide wire 1 </ b> F of the present embodiment has a rigidity imparting member 7 installed so as to cover the outer periphery of the second wire 3 (the distal end portion 32) in the vicinity of the proximal end side of the welded portion 14. Since the rigidity imparting member 7 is installed, the bending rigidity of the guide wire 1F in the vicinity of the distal end portion 32 of the second wire 3 is increased.
[0115]
As described above, since the second wire 3 is made of a relatively flexible material (low elastic modulus), for example, a superelastic alloy, the bending rigidity of the proximal end portion 23 of the first wire 2 is the second. It is larger than the bending rigidity of the tip portion 32 of the wire 3. Therefore, when it is assumed that there is no rigidity imparting member 7, the bending rigidity of the guide wire 1 </ b> F changes with the weld 14 interposed therebetween. However, in this embodiment, the distal end portion 32 of the second wire 3 is caused by the rigidity imparting member 7. Since the bending rigidity in the vicinity is increased, there is little difference from the bending rigidity of the proximal end portion 23 of the first wire 2. Therefore, in the guide wire 1 </ b> F, the change along the longitudinal direction of the bending rigidity at the vicinity including the welded portion 14 can be made gentle (smooth). As a result, the kink resistance (bending resistance) in the vicinity of the welded portion 14 is improved, and the guide wire 1F has excellent operability. The effect of the rigidity imparting member 7 is the same for the torsional rigidity of the guide wire 1F.
[0116]
In the present embodiment, the rigidity imparting member 7 is formed of a tubular (cylindrical) member. The outer diameter of the rigidity imparting member 7 is substantially the same as the outer diameter of the proximal end portion 23 of the first wire 2. That is, the outer diameter of the distal end portion 32 of the second wire 3 is smaller than the outer diameter of the proximal end portion 23 of the first wire 2. The distal end surface of the rigidity imparting member 7 is in contact with the connection end surface 21 (base end surface) of the first wire 2. With such a configuration, bending and torsional forces are reliably transmitted between the first wire 2 and the rigidity-imparting member 7, and rigidity along the longitudinal direction (flexural rigidity, The change in torsional rigidity can be made more gradual (smooth).
[0117]
In the guide wire 1F of the present embodiment, the boundary between the distal end of the rigidity imparting member 7 and the first wire 2 and the boundary between the proximal end of the rigidity imparting member 7 and the second wire 3 are stepped. It constitutes a smooth continuous surface with no gap. As a result, the guide wire 1F has reduced sliding resistance, and more excellent slidability can be obtained.
[0118]
In the present embodiment, the inner diameter and the outer diameter of the rigidity imparting member 7 are substantially constant along the longitudinal direction (axial direction), and thus the bending rigidity of the rigidity imparting member 7 is the longitudinal direction of the guide wire 1F ( The rigidity imparting member 7 may be one whose bending rigidity varies along the longitudinal direction.
[0119]
The constituent material of the rigidity imparting member 7 is not particularly limited. For example, various metal materials such as stainless steel, cobalt alloy, solder material, brazing material, superelastic alloy, fluorine resin such as polytetrafluoroethylene, epoxy, etc. Various resin materials (plastics) such as resin and polyimide can be used.
[0120]
In addition, the constituent material of the rigidity imparting member 7 is preferably a material having substantially the same elastic modulus as that of the second wire 3 or a material having a higher elastic modulus. Thereby, the rigidity (bending rigidity, torsional rigidity) of the distal end portion 32 of the second wire 3 can be further increased, and as a result, the change in the rigidity (bending rigidity, torsional rigidity) along the longitudinal direction of the guide wire 1F. Can be made more gradual (smooth).
[0121]
The fixing method of the rigidity imparting member 7 is not particularly limited, and examples thereof include welding, brazing, adhesion with an adhesive, and caulking. The rigidity imparting member 7 may be installed after the second wire 3 and the first wire 2 are welded. After the rigidity imparting member 7 is installed at the distal end portion 32 of the second wire 3, The first wire 2 may be welded. Furthermore, the rigidity imparting member 7 is not limited to a method of mounting a separately manufactured member, and may be formed, for example, so as to be deposited on the outer periphery of the distal end portion 32 of the second wire 3 by thermal spraying.
[0122]
The length of the rigidity imparting member 7 is not particularly limited, but is preferably about 3 to 100 mm, and more preferably about 5 to 10 mm.
[0123]
In addition, the shape (form) of the rigidity imparting member 7 is not limited to the illustrated configuration, and may be a coil shape, for example.
[0124]
As mentioned above, although the guide wire of this invention was demonstrated about embodiment of illustration, this invention is not limited to this, Each part which comprises a guide wire is a thing of arbitrary structures which can exhibit the same function. Can be substituted. Moreover, arbitrary components may be added.
[0125]
In addition, the guide wire of the present invention may be a combination of any two or more configurations (features) of the above embodiments.
[0126]
【The invention's effect】
As described above, according to the present invention, the tip portion of the guide wire on which the first wire is installed can be reshaped (shaped) easily and reliably, and the portion on which the second wire is installed Can obtain excellent flexibility and a characteristic that is difficult to bend, and as a result, a guide wire with excellent operability can be obtained.
[0127]
In addition, the above-described effect can be achieved with a simple structure that does not provide a separate member from the wire body such as a reshape ribbon. Furthermore, the manufacturing is easy and the manufacturing cost can be reduced.
[0128]
Further, by connecting the first wire and the second wire by welding, the coupling strength of the connecting portion (welded portion) is high, and torsional torque and pushing force can be reliably transmitted from the second wire to the first wire. it can.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a first embodiment of a guide wire of the present invention.
2 is a diagram showing a procedure for connecting a first wire and a second wire in the guide wire shown in FIG. 1; FIG.
FIG. 3 is a schematic view for explaining an example of use of the guide wire of the present invention.
FIG. 4 is a schematic diagram for explaining an example of use of the guide wire of the present invention.
FIG. 5 is a longitudinal sectional view showing a second embodiment of the guide wire of the present invention.
FIG. 6 is a longitudinal sectional view showing a third embodiment of the guide wire of the present invention.
FIG. 7 is a longitudinal sectional view showing a fourth embodiment of the guide wire of the present invention.
FIG. 8 is a longitudinal sectional view showing a fifth embodiment of the guide wire of the present invention.
9 is a diagram showing a procedure for connecting a first wire and a second wire in the guide wire shown in FIG. 8. FIG.
FIG. 10 is a longitudinal sectional view showing a sixth embodiment of the guide wire of the present invention.
[Explanation of symbols]
1A, 1B, 1C, 1D, 1E, 1F Guide wire
2 First wire
21 Connection end face
22 Small cross section
23 Base end
3 Second wire
31 Connection end face
32 Tip
321 Hollow part
4 Coils
5 Third wire
6 Step filling material
7 Stiffening member
10 Wire body
11, 12, 13 Fixing material
14 Welded part
15 Outer diameter gradually decreasing part
16 Welded part
17 Plastic Jacket
18 Overlap
20 Balloon catheter
201 balloon
30 guiding catheter
40 Aortic arch
50 Right coronary artery
60 Right coronary artery opening
70 Vascular stenosis

Claims (6)

A linear first wire made of a reshapeable metal material disposed on the distal end side;
A linear second wire that is arranged on the base end side of the first wire and is made of an alloy exhibiting pseudoelasticity;
The first wire has a small cross-sectional area portion in the vicinity of a welded portion between the first wire and the second wire, whose cross-sectional area is smaller than the cross-sectional area of the tip end portion of the second wire,
The guide wire, wherein the first wire and the second wire are connected by welding. The guide wire according to claim 1, further comprising a step filling member that fills a step formed on an outer periphery of the small cross-sectional area portion. The guide wire according to claim 2, wherein the step filling member is made of a flexible material that contributes little to the rigidity of the guide wire. It is arranged on the base end side of the second wire, and includes a linear third wire made of a material having a larger elastic modulus than that of the constituent material of the second wire, and the second wire and the third wire are: The guide wire according to any one of claims 1 to 3, wherein the guide wire is connected by welding. The base portion of the first wire and the tip portion of the second wire have an overlapping portion that is overlapped along the axial direction of both wires, and in the overlapping portion, the first wire and the The guide wire according to any one of claims 1 to 4, wherein the second wire is welded. A rigidity-imparting member is provided in the vicinity of the proximal end side of the welded portion between the first wire and the second wire so as to cover the outer periphery of the second wire and increases the bending rigidity near the distal end portion of the second wire. The guide wire according to any one of claims 1 to 4 .

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