JP4734029B2 - Guide wire manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a guide wire, and more particularly to a method for manufacturing a guide wire used when a catheter is introduced into a body cavity such as a blood vessel or a bile duct.

  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.

  Furthermore, the guide wire is used to guide each treatment device to the vicinity of the bile duct and the pancreatic duct lesion by the following method, for example, in the treatment of the lesion of the bile duct and pancreatic duct.

[1] ERCP (endoscopic retrograde cholangiopancreatography)
A method in which an endoscope is inserted into the descending portion of the duodenum, and while the Vater papilla is viewed in front with the endoscope, a contrast cannula is inserted into the bile duct and pancreatic duct, a contrast agent is injected, and X-ray imaging is performed.

[2] EST (endoscopic sphincterotomy)
A papillotome for incision is inserted into the opening of the duodenal papilla and the papillary sphincter is incised at high frequency.

[3] EPBD (endoscopic papillary balloon dilation)
A method of expanding the nipple with a balloon via an endoscope and removing the bile duct gallstones.

  Blood vessels that require PTCA surgery are intricately curved, and the guide wire used to insert a balloon catheter into the blood vessel has moderate bending flexibility and resilience, and manipulation at the proximal end. Pushability and torque transmission properties for transmission (collectively these are referred to as “operability”) and kink resistance (bending resistance) are required. Among these characteristics, as a structure for obtaining moderate flexibility, a structure having a metal coil having flexibility for bending around a thin tip core material of a guide wire, and for providing flexibility and resilience There is a guide wire using a super elastic wire such as Ni-Ti as a core material.

  Conventionally, the guide wire is composed of a single core material from the proximal end to the distal end, and the core material is often made of a material having a relatively high elastic modulus in order to improve the operability of the guide wire. As a result, the flexibility of the guide wire tip tends to be lost. Further, when a material having a relatively low elastic modulus is used as the core material in order to obtain flexibility at 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 achieve both required flexibility and operability.

  In addition, the guide wire used in the above-described transendoscopic procedure is a catheter in a state where the endoscope is bent in the body cavity, the guide wire is bent at the forceps raising base, and the contrast agent is fixed. Therefore, torque transmission performance and pushing force (pushability: pushability) are impaired. Further, depending on the device to be combined, it is necessary to use a guide wire with a thin outer diameter. However, when the outer diameter is reduced, there is a problem that the rigidity of the guide wire is lowered, the torque transmission property and the pushing force are reduced, and it is difficult to guide each treatment device to the target site.

  In order to improve such a defect, for example, a Ni-Ti alloy wire is used as a core material, and heat treatment is performed on the distal end side and the proximal end side under different conditions to increase the flexibility of the distal end portion. A guide wire with increased rigidity has been proposed (see, for example, Patent Document 1).

  However, there is a limit to the control of flexibility by such heat treatment, and even if sufficient flexibility is obtained at the distal end portion, there is a case where satisfactory rigidity is not always obtained at the proximal end side.

  In addition, a flexible first wire disposed on the distal end side, a second wire having high rigidity disposed on the proximal end side, a first wire and a second wire are connected to each other, and a groove and There has been proposed a guide wire that includes a tubular connecting member having a slit, and the connecting member is configured such that rigidity gradually increases from the distal end side toward the proximal end side (see, for example, Patent Document 2).

  In such a guide wire, wires having desired characteristics can be arranged on the distal end side and the proximal end side, respectively. However, since both wires are connected via a tubular connecting member, the bonding strength of both wires can be increased. There is a problem that the torque cannot be increased and the torque transmission cannot be sufficiently obtained. In addition, there is a manufacturing problem that it takes time to connect the wires.

Japanese Examined Patent Publication No. 4-60675 Japanese Patent Laid-Open No. 10-118055

An object of the present invention is to provide a method of manufacturing a guide wire that is excellent in operability and has high bonding strength between a first wire and a second wire while ensuring flexibility of a tip portion.

  Such an object is achieved by the present inventions (1) to (6) below. Moreover, it is preferable that it is following (7)-(18).

(1) A linear first wire made of a metal material, and a linear second wire made of a metal material and having a distal end outer diameter larger than the outer diameter of the proximal end of the first wire. A first step of preparing and joining the proximal end of the first wire and the distal end of the second wire by welding;
By removing and shaping a part of the solidified product of the molten metal generated by welding the first wire and the second wire in the first step, the base end of the first wire and the second wire And a second step of forming a metal coating layer that fills the step caused by the difference in the outer diameter of the tip.

(2) The method for manufacturing a guide wire according to (1), wherein the metal coating layer is formed by machining the solidified product of the molten metal.

(3) The said metal coating layer is a manufacturing method of the guide wire as described in said (1) or (2) which has the part which the thickness reduces gradually toward a front-end | tip direction.

(4) The guide wire manufacturing method according to any one of (1) to (3), wherein the distal end portion of the second wire includes a tapered portion whose outer diameter changes along the longitudinal direction.

(5) The guide wire manufacturing method according to (4), wherein the tapered portion has an outer diameter that gradually increases from a distal end toward a proximal end.

(6) The metal coating layer has a tapered portion whose outer diameter gradually decreases from the proximal end toward the distal end, where the taper angle of the tapered portion is β and the taper angle of the tapered portion is α. ,
The guide wire manufacturing method according to (5), wherein the relationship 0.5 ≦ β / α ≦ 2 is satisfied.

(7) The guide wire manufacturing method according to any one of (1) to (6), wherein an outer diameter of the proximal end portion of the first wire is substantially constant along a longitudinal direction.

(8) The guide wire manufacturing method according to any one of (1) to (7), wherein the first wire and the second wire are made of the same or the same kind of metal material.

(9) The guide wire manufacturing method according to any one of (1) to (7), wherein each of the first wire and the second wire is made of a superelastic alloy.

(10) The guide wire manufacturing method according to any one of (1) to (9), wherein an average thickness of the metal coating layer is 2 to 300 μm.

(11) The guide wire manufacturing method according to any one of (1) to (10), wherein the guide wire includes a spiral coil that covers at least a portion on a distal end side of the first wire.

(12) The guide wire manufacturing method according to any one of (1) to (11), wherein a distal end portion of the first wire has a contrast portion having X-ray contrast properties.

(13) The guide wire manufacturing method according to any one of (1) to (12), wherein a resin coating layer is provided on an outer periphery of the first wire and / or the second wire.

(14) The guidewire manufacturing method according to any one of (1) to (13), wherein a resin coating layer made of a resin material capable of reducing friction is provided on an outer periphery of the second wire.

(15) The guide wire manufacturing method according to any one of (1) to (14), wherein a resin coating layer made of a flexible material is provided on an outer periphery of the first wire.

(16) The guide wire manufacturing method according to any one of (13) to (15), wherein the resin coating layer is made of a thermoplastic elastomer, a silicone resin, or a fluorine resin.

(17) The guide wire manufacturing method according to any one of (13) to (16), wherein the tip of the first wire is covered with the resin coating layer without being exposed.

(18) The guidewire manufacturing method according to any one of (1) to (17), wherein a hydrophilic material is coated on an outer surface of at least a tip portion of the guidewire .

According to the guide wire manufacturing method of the present invention, the flexible first wire and the second wire having higher rigidity than the first wire are joined by welding, so that the distal end side of the guide wire is flexible. It is possible to obtain a guide wire excellent in push-in property, torque transmission property and follow-up property by sufficiently securing the safety and improving the safety and obtaining sufficient rigidity on the proximal end side of the guide wire. Such an effect is exhibited not only in a guide wire having a normal outer diameter but also in a guide wire having a small outer diameter. Therefore, the guide wire manufactured by the guide wire manufacturing method of the present invention exhibits excellent operability in a body cavity such as a curved catheter, an endoscope, a blood vessel, a bile duct, and a pancreatic duct. .

  Moreover, when the difference in rigidity between the first wire and the second wire is mainly due to the difference in the outer diameters of both wires, both wires can be made of the same or the same material. As a result, the bonding strength between the first wire and the second wire can be increased. Therefore, even when a stress such as bending or tension acts on the guide wire, the joint portion between the first wire and the second wire is not detached, and the reliability is high.

  In particular, by joining (connecting) the first wire and the second wire by welding and forming a metal coating layer around the welded portion, the bond strength of the welded portion is further increased, and the first wire is connected to the first wire. Torsional torque and pushing force can be more reliably transmitted to the wire.

  In addition, since the metal coating layer is provided so as to fill the step caused by the outer diameter difference between the first wire and the second wire, when bending or twisting acts on the guide wire, the stress is applied to the welded portion (stepped portion). ) And the concentration of stress on the welded portion is prevented. Therefore, bending and torsional stresses are transmitted smoothly before and after the welded portion, and steep kinks (bending) and twisting can be effectively prevented.

  In the present invention, since the metal coating layer is formed by machining the solidified product of the molten metal generated by welding the first wire and the second wire, the metal coating layer is formed as a separate member. Compared with the case where it does, manufacture is easy, and the adhesion strength of the metal coating layer to the first wire and the second wire is also strong, and even if an excessive stress is applied, damage or the like does not occur. In particular, since the metal coating layer is composed of the material of the first wire and / or the second wire, it can be securely fixed to the first wire and the second wire and can be easily shaped. The wire main body can form a surface with a continuous surface without a step before and after the welded portion.

  In addition, when a resin coating layer, particularly a resin coating layer made of a material capable of reducing friction, is provided, the slidability of the guide wire in the catheter or the like is improved, and the operability of the guide wire is further improved. Can be. By reducing the sliding resistance of the guide wire, it is possible to more reliably prevent kinking and twisting of the guide wire, particularly kinking and twisting in the vicinity of the welded portion.

  Further, when a resin coating layer made of a flexible material is provided on the outer periphery of the first wire, particularly when the tip of the first wire is covered with the resin coating layer without being exposed. Further, it is possible to more reliably prevent damage to the inner wall of the blood vessel during insertion into the blood vessel or the like, and safety can be further improved.

It will be described in detail with reference to preferred embodiments shown in the accompanying drawings moth guide wire.

Figure 1 is a longitudinal sectional view showing an embodiment of a gas guide wire, FIG. 2 is a longitudinal sectional view showing an enlarged vicinity of the joint portion of the wire body in moth guide wire. For convenience of explanation, the right side in FIGS. 1 and 2 is referred to as “base end”, and the left side is referred to as “tip”. Further, in FIG. 1 and FIG. 2, for easy understanding, the length direction of the guide wire is shortened and the thickness direction of the guide wire is exaggerated and schematically illustrated. The vertical ratio is different from the actual one.

  A guide wire 1 shown in FIG. 1 is a guide wire for a catheter that is used by being inserted into the lumen of a catheter (including an endoscope), and includes a first wire 2 disposed on the distal end side, and a first wire 2. The wire main body 10 formed by joining (connecting) the second wire 3 disposed on the base end side of the wire by welding 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.

  The first wire 2 is composed of a wire material having flexibility or elasticity. 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 first wire 2 has a portion having a constant outer diameter and a tapered portion (outer diameter gradually decreasing portion) in which the outer diameter gradually decreases in the distal direction. The latter may be one place or two places or more. In the illustrated embodiment, the outer diameter gradually decreasing portion 15 is provided at one place.

  By having the outer diameter gradually decreasing portion 15 as described above, the rigidity (bending rigidity, torsional rigidity) of the first wire 2 can be gradually decreased toward the distal end direction. In addition, it is possible to obtain good flexibility, improve followability to blood vessels and the like and safety, and prevent bending and the like.

  The taper angle (decrease rate of the outer diameter) of the outer diameter gradually decreasing portion 15 may be constant along the longitudinal direction of the wire, or there may be a portion that varies along the longitudinal direction. For example, a portion in which a taper angle (an outer diameter reduction rate) and a relatively small portion are alternately formed a plurality of times may be used.

  The portion of the first wire 2 on the proximal end side (the portion on the proximal end side from the outer diameter gradually decreasing portion 15) has a constant outer diameter up to the proximal end of the first wire 2.

  The distal end of the second wire 3 is connected (coupled) to the proximal end of the first wire 2 by welding. The second wire 3 is composed of a wire material having flexibility or elasticity. Although the length of the 2nd wire 3 is not specifically limited, It is preferable that it is about 20-4800 mm.

  A tapered portion 16 whose outer diameter gradually increases from the distal end (the most distal end of the second wire 3) toward the proximal end is formed at the distal end of the second wire 3. The outer diameter of the second wire 3 is substantially constant along the wire longitudinal direction on the proximal end side with respect to the tapered portion 16.

  When the outer diameter of the distal end of the second wire 3 (the distal end of the tapered portion 16) is D2, and the outer diameter of the proximal end of the first wire 2 is D1, the relationship D1 <D2 is established. In particular, D1 / D2 is preferably about 0.2 to 0.98, and more preferably about 0.5 to 0.9. By setting it as such a range, while ensuring the area of the junction part 14 of the 1st wire 2 and the 2nd wire 3, sufficient joining strength is obtained, and the 1st wire 2 shall be rich in flexibility. it can.

  The average outer diameter of the first wire 2 is smaller than the average outer diameter of the second wire 3. As a result, the guide wire 1 is highly flexible on the first wire 2 on the distal end side and relatively high on the second wire 3 on the proximal end side. And excellent operability (pushability, torque transmission, etc.).

  And by having the taper part 16 in the front-end | tip part of the 2nd wire 3, the physical characteristic from the 2nd wire 3 to the 1st wire 2, especially elasticity changes smoothly, and the junction part ( Excellent pushability and torque transmission performance are exhibited before and after the joint surface 14, and kink resistance is also improved.

  The constituent materials of the first wire 2 and the second wire 3 are not particularly limited, and for example, stainless steel (for example, SUS304, SUS303, SUS316, SUS316L, SUS316J1, SUS316J1L, SUS405, SUS430, SUS434, SUS444, SUS429, Various metal materials such as SUS430F, all types of SUS such as SUS302), piano wires, cobalt alloys, alloys showing pseudoelasticity (including superelastic alloys) can be used. The alloys shown (including superelastic alloys) are preferred, more preferably superelastic alloys.

  Since the superelastic alloy is relatively flexible, has a resilience, and is difficult to bend, the guide wire 1 can be sufficiently formed at the tip side by configuring the first wire 2 with the superelastic alloy. Flexibility and resilience to bending, improved followability to complicatedly bent and bent blood vessels, etc., and more excellent operability, and even if the first wire 2 repeats bending and bending deformation Since the bend crease is not attached due to the resilience provided in the first wire 2, it is possible to prevent the operability from being lowered due to the bend crease in the first wire 2 during use of the guide wire 1.

  Pseudoelastic alloys include any shape of stress-strain curve due to tension, including those that can measure the transformation point of As, Af, Ms, Mf, etc., and those that cannot be measured. However, everything that returns to its original shape by removing stress is included.

  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. In addition, the superelastic alloy represented by the Ni-Ti system alloy is excellent also in the adhesiveness of the resin coating layers 8 and 9 mentioned later.

  The cobalt-based alloy has a high elastic modulus when used as a wire and has an appropriate elastic limit. For this reason, the wire comprised by the cobalt type alloy is excellent in torque transferability, and problems, such as buckling, do not arise very much. Any cobalt-based alloy may be used as long as it contains Co as a constituent element, but it contains Co as a main component (Co-based alloy: Co content in the elements constituting the alloy) Is preferable, and a Co—Ni—Cr alloy is more preferably used. By using an alloy having such a composition, the above-described effects become more remarkable. In addition, an alloy having such a composition has a high elastic modulus and can be cold-formed even as a high elastic limit, and by reducing the diameter while sufficiently preventing buckling from occurring due to the high elastic limit. And can have sufficient flexibility and rigidity to be inserted into a predetermined portion.

  Examples of the Co—Ni—Cr alloy include alloys having a composition of 28 to 50 wt% Co-10 to 30 wt% Ni-10 to 30 wt% Cr—remainder Fe, and a part of the other elements (substitution elements). Alloys substituted with are preferred. The inclusion of a substitution element exhibits a unique effect depending on the type. For example, the strength of the second wire 3 can be further improved by including at least one selected from Ti, Nb, Ta, Be, and Mo as the substitution element. In addition, when an element other than Co, Ni, and Cr is included, the content (of the entire substituted element) is preferably 30 wt% or less.

  Further, a part of Co, Ni, and Cr may be substituted with other elements. For example, a part of Ni may be substituted with Mn. Thereby, the further improvement of workability etc. can be aimed at, for example. Further, a part of Cr may be replaced with Mo and / or W. Thereby, the further improvement of an elastic limit, etc. can be aimed at. Among Co—Ni—Cr alloys, Co—Ni—Cr—Mo alloys containing Mo are particularly preferable.

  As a specific composition of the Co—Ni—Cr alloy, for example, [1] 40 wt% Co-22 wt% Ni-25 wt% Cr-2 wt% Mn—0.17 wt% C-0.03 wt% Be—balance Fe [2] 40 wt% Co-15 wt% Ni-20 wt% Cr-2 wt% Mn-7 wt% Mo-0.15 wt% C-0.03 wt% Be-balance Fe, [3] 42 wt% Co-13 wt% Ni- 20 wt% Cr-1.6 wt% Mn-2 wt% Mo-2.8 wt% W-0.2 wt% C-0.04 wt% Be-balance Fe, [4] 45 wt% Co-21 wt% Ni-18 wt% Cr- 1 wt% Mn-4 wt% Mo-1 wt% Ti-0.02 wt% C-0.3 wt% Be-balance Fe, [5] 34 wt% Co-21 wt% Ni-14 wt% Cr-0.5 wt% Mn-6w % Mo-2.5wt% Nb-0.5wt% Ta- balance being Fe, and the like. The Co—Ni—Cr alloy referred to in the present invention is a concept that includes these alloys.

  The first wire 2 and the second wire 3 may be made of different materials, but are preferably made of the same or the same kind of metal material (the main metal material in the alloy is the same). Thereby, the joint strength of the joint part (welded part) 14 becomes higher, and even if the outer diameter of the joint part 14 is small, excellent torque transmission properties and the like are exhibited without causing separation.

  In this case, each of the first wire 2 and the second wire 3 is preferably made of the superelastic alloy described above, and more preferably made of a Ni—Ti alloy. As a result, excellent flexibility on the distal end side of the taper portion 16 of the wire body 10 can be ensured, and sufficient rigidity (bending rigidity, torsional rigidity) can be secured on the proximal end portion of the wire body 10. . As a result, the guide wire 1 obtains excellent pushability and torque transmission and secures good operability, and obtains good flexibility and resilience on the distal end side to follow blood vessels, bile ducts and pancreatic ducts. And safety are improved.

  A coil 4 is disposed on the outer periphery of the distal end portion of the first wire 2. The coil 4 is a member formed by winding a wire (thin wire) in a spiral shape, and is installed so as to cover at least a portion on the distal end side of the first wire 2. In the configuration shown in the drawing, the portion on the distal end side of the first wire 2 is inserted through a substantially central portion inside the coil 4. Further, the distal end portion of the first wire 2 is inserted in a non-contact manner with the inner surface of the coil 4. The joint portion 14 is located closer to the proximal end than the proximal end 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, tungsten, and alloys containing these (for example, platinum-iridium alloy). 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. Further, the coil 4 may be composed of different materials on the distal end side and the proximal end side. 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 that relatively transmits X-rays (such as stainless steel). 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 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 first wire 2 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 a body cavity such as a blood vessel, the distal end surface of the fixing material 12 is preferably rounded.

  In the present embodiment, since such a coil 4 is installed, the first wire 2 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.

  The first wire 2 and the second wire 3 constituting the guide wire body 10 are connected and fixed by welding. Accordingly, a high bonding strength can be obtained at the bonded portion (welded portion) 14 between the first wire 2 and the second wire 3 by a simple method. The pushing force is reliably transmitted to the first wire 2.

  The method for welding the first wire 2 and the second wire 3 is not particularly limited, and examples thereof include friction welding, spot welding using a laser, butt resistance welding such as butt seam welding, and the like. Butt resistance welding is particularly preferred because high joint strength is obtained.

  As described above, the outer diameter D1 of the proximal end of the first wire 2 is smaller than the outer diameter D2 of the distal end of the second wire 3 (the distal end of the tapered portion 16), so that both the wires 2 and 3 are welded. When attached, the step 5 is caused by the difference between the outer diameters D2 and D1 (hereinafter referred to as “outer diameter difference”).

  And after joining both the wires 2 and 3 by welding, the metal coating layer 6 which fills the said level | step difference 5 in the outer peripheral part of the junction part 14 of both the wires 2 and 3 is formed. Hereinafter, the shape of the metal coating layer 6 will be described.

  As shown in FIGS. 2 to 4, the distal end side of the joint portion 14 is the first wire 2 having a substantially constant outer diameter, and the proximal end side of the joint portion 14 gradually increases in the outer diameter in the proximal direction. The metal covering layer 6 is formed so as to fill the step 5 caused by the difference in outer diameter between the distal end of the first wire 2 and the proximal end of the tapered portion 16.

  The metal coating layer 6 has a tapered portion 61 whose outer diameter gradually decreases from the proximal end toward the distal end. In the example of FIGS. 2 to 4, almost the entire metal coating layer 6 is configured by the tapered portion 61, but the tapered portion 61 may be partially formed.

  Such a metal coating layer 6 has a tapered portion 61 whose thickness gradually decreases in the tip direction. In particular, in the example of FIGS. 2 to 4, the thickness of the metal coating layer 6 decreases linearly toward the tip direction.

  When the taper angle of the tapered portion 61 of the metal coating layer 6 (the angle of the outer peripheral surface with respect to the axis of the wire body 10) is β and the taper angle of the taper portion 16 of the second wire 3 is α, 0.5 ≦ It is preferable to satisfy the relationship β / α ≦ 2, and it is more preferable to satisfy the relationship 0.75 ≦ β / α ≦ 1.25. When such a relationship is satisfied, since β is a value relatively close to α, the rate of change (decrease) in the outer diameter from the tapered portion 16 of the second wire 3 to the first wire 2 becomes smaller. Therefore, the physical characteristics from the second wire 3 to the first wire 2, particularly the elasticity, changes smoothly, and excellent pushability and torque transmission before and after the joint portion (joint surface) 14 of both the wires 2 and 3. And kink resistance is improved.

  In the configuration example shown in FIG. 2, a case where β≈α is shown. The configuration example shown in FIG. 3 shows a case where β> α. In this case, it is preferable that 1 <β / α ≦ 2. The configuration example shown in FIG. 4 shows a case where β <α. In this case, it is preferable that 0.5 ≦ β / α <1. Among these, in the configuration example shown in FIGS. 3 and 4, particularly in the configuration example shown in FIG. 4, the metal coating layer 6 has a difference in angle between the outer peripheral surface of the proximal end portion of the first wire 2 and the outer peripheral surface of the tapered portion 16. Since it is formed so as to relax, the above-described effects are more prominently preferable.

  By forming such a metal coating layer 6, the steep outer diameter change (step 5) on the tip side of the joint portion 14 can be relaxed, and stress concentration in the weld portion 14 can be eliminated or alleviated, The physical characteristics from the second wire 3 to the first wire 2, particularly the rigidity and elasticity, change smoothly, and excellent pushability and torque transmission before and after the joint portion 14 of both wires 2 and 3 are exhibited. Kink property is also improved.

  The metal coating layer 6 is composed of a solidified product of molten metal (melt) generated by welding the wires 2 and 3. Therefore, the constituent material of the metal coating layer 6 includes at least one of the constituent metal of the first wire 2 and the constituent metal of the second wire 3, and usually includes both. In particular, as described above, when the first wire 2 and the second wire 3 are made of the same or the same kind of metal material, the constituent material of the metal coating layer 6 also has the same metal composition.

  Further, the metal coating layer 6 is formed by machining the solidified product of the molten metal, for example, into a shape as shown in FIGS. Thereby, the metal coating layer 6 can be made into a desired shape or surface property, and the pushability, torque transmission property, and kink resistance of the guide wire 1 can be further improved. In addition, as machining, it can carry out combining 1 type, or 2 or more types among grinding | polishing, grinding | polishing, laser processing etc., for example. Further, instead of machining or after machining, chemical treatment such as etching may be performed.

  It is preferable that the metal coating layer 6 forms a continuous surface with no step by such shaping. That is, the outer peripheral surface of the base end portion of the metal coating layer 6 and the outer peripheral surface of the tip end portion of the tapered portion 16 constitute a continuous surface without a step (see FIG. 2).

  Although the average thickness of the metal coating layer 6 is not particularly limited, it is preferably about 2 to 300 μm, more preferably about 1 to 200 μm, and more preferably about 1 to 100 μm. If the level difference 5 is too large, the thickness of the metal coating layer 6 tends to increase. When the constituent metals of the first wire 2 and the second wire 3 are different, the physical characteristics (stiffness) between the wires 2 and 3 are different. , Elasticity, etc.) may not change smoothly. Moreover, when the thickness of the metal coating layer 6 is too thin, there exists a possibility that the function of the metal coating layer 6 mentioned above cannot fully be exhibited.

  The length of the metal coating layer 6 in the wire longitudinal direction is not particularly limited, but is preferably about 0.5 to 2.0 mm, and more preferably about 0.5 to 1.0 mm.

Such a metal coating layer 6 is formed as follows, for example.
The first wire 2 and the second wire 3 are brought into pressure contact with the proximal end of the first wire 2 and the distal end of the second wire 3 while a predetermined voltage is applied by, for example, a butt welder. By this pressure contact, a thin (for example, about 0.01 to 50 μm) molten layer is formed in the contact portion, and when the molten layer is cooled and solidified, a joint portion 14 is formed, and the first wire 2 and the second wire 3 Are firmly joined. During this welding, the melt accumulates inside the step 5 (for example, a region in the range of about 0.2 to 8 mm from the joint portion 14 in the distal direction), the melt is solidified, as if the outside of the first wire 2. A raised portion having an increased diameter is formed. This raised portion is a solidified melt of the first wire 2 and / or the second wire 3.

  The raised portion of the melt is formed beyond the outer diameter D2. Therefore, the metal coating layer 6 having a desired shape as shown in FIGS. 2 to 4 is obtained by appropriately removing the raised portions and shaping (shaping the shape). Examples of the shaping method include mechanical processing such as grinding, polishing, and laser processing, and chemical processing such as etching on the raised portion. After machining, chemical treatment may be performed for the purpose of finishing or the like. By such shaping, the outer peripheral surface of the metal coating layer 6 can be made a substantially smooth surface.

  As shown in FIG. 2, the tapered portion 61 of the metal coating layer 6 has an outer diameter that gradually increases linearly from the distal end toward the proximal end. However, the tapered portion 61 forms a concave surface. May be formed, or conversely, a convex surface may be formed. Moreover, the structure which coat | covered all or one part of the metal coating layer 6 with the coating layer by resin etc. which are mentioned later may be sufficient.

As shown in FIG. 1, the wire body 10 has resin coating layers 8 and 9 that cover all or part of the outer peripheral surface (outer surface) thereof. In the illustrated embodiment, resin coating layers 8 and 9 are provided on the outer circumferences of the first wire 2 and the second wire 3, respectively.
Although these resin coating layers 8 and 9 can be formed for various purposes, as an example, the guide wire 1 is reduced by reducing the friction (sliding resistance) of the guide wire 1 and improving the slidability. May improve operability.

  Unlike the illustration, the resin coating layer 8 or 9 may be provided so as to cover the outer periphery of the metal coating layer 6. Thereby, the outer diameter change (change in taper angle, etc.) of the wire body 10 can be further mitigated, the pushability, torque transmission property, and kink resistance of the guide wire 1 can be further improved, and the guide wire The moving operability in the longitudinal direction of 1 can be improved.

  In order to reduce the friction (sliding resistance) of the guide wire 1, the resin coating layers 8 and 9 are preferably made of a material that can reduce friction as described below. Thereby, the frictional resistance (sliding resistance) with the inner wall of the catheter used together with the guide wire 1 is reduced, the slidability is improved, and the operability of the guide wire 1 in the catheter becomes better. In addition, since the sliding resistance of the guide wire 1 is reduced, when the guide wire 1 is moved and / or rotated in the catheter, kinks (bending) and twisting of the guide wire 1, especially kinks in the vicinity of the joint 14, Twist can be prevented more reliably.

  Examples of materials that can reduce such friction include polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polyesters (PET, PBT, etc.), polyamides, polyimides, polyurethanes, polystyrenes, polycarbonates, silicone resins, fluorine resins ( PTFE, ETFE, etc.) or a composite material thereof.

  In particular, when a fluorine-based resin (or a composite material containing the same) is used, the frictional resistance (sliding resistance) between the guide wire 1 and the inner wall of the catheter is more effectively reduced, and slidability is improved. This can improve the operability of the guide wire 1 in the catheter. In addition, this makes it possible to more reliably prevent kinking (bending) and twisting of the guide wire 1, particularly kinking and twisting in the vicinity of the welded portion, when the guide wire 1 is moved and / or rotated in the catheter.

  In addition, when a fluororesin (or a composite material containing the same) is used, the wire body 10 can be coated with the resin material heated by a method such as baking or spraying. Thereby, the adhesiveness between the wire body 10 and the resin coating layers 8 and 9 is particularly excellent.

  Further, when the resin coating layers 8 and 9 are made of a silicone resin (or a composite material containing the same), the resin coating layers 8 and 9 are heated when the resin coating layers 8 and 9 are formed (covered on the wire body 10). Even if it does not exist, the resin coating layers 8 and 9 adhered to the wire body 10 reliably and firmly can be formed. That is, when the resin coating layers 8 and 9 are made of a silicone resin (or a composite material containing the same), a reaction-curing material or the like can be used, so that the resin coating layers 8 and 9 are formed. It can be performed at room temperature. Thus, by forming the resin coating layers 8 and 9 at room temperature, the coating can be easily performed, and the bonding strength between the first wire 2 and the second wire 3 in the welded portion 14 is sufficiently maintained. The guide wire can be operated.

  Further, the resin coating layers 8 and 9 (particularly, the resin coating layer 8 on the distal end side) can be provided for the purpose of improving safety when the guide wire 1 is inserted into a blood vessel or the like. For this purpose, the resin coating layers 8 and 9 are preferably made of a material having a high flexibility (soft material, elastic material).

  Examples of such flexible materials include polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polyester (PET, PBT, etc.), polyamide, polyimide, polyurethane, polystyrene, silicone resin, polyurethane elastomer, polyester elastomer, polyamide. Examples thereof include thermoplastic elastomers such as elastomers, various rubber materials such as latex rubber and silicone rubber, or composite materials in which two or more thereof are combined.

  In particular, when the resin coating layers 8 and 9 are made of the above-described thermoplastic elastomer or various rubber materials, the flexibility of the distal end portion of the guide wire 1 is further improved. In addition, it is possible to more reliably prevent damage to the inner wall of the blood vessel, and the safety is extremely high.

  Each of the resin coating layers 8 and 9 may be a laminate of two or more layers. Moreover, the resin coating layer 8 and the resin coating layer 9 may be made of the same material or different materials. For example, the resin coating layer 8 positioned on the distal end side of the guide wire 1 is made of the above-described flexible material (soft material, elastic material), and the resin coating layer 9 positioned on the proximal end side of the guide wire 1 is The material can reduce friction as described above. Thereby, both improvement of slidability (operability) and improvement of safety can be achieved.

  The thickness of the resin coating layers 8 and 9 is not particularly limited, and is appropriately determined in consideration of the purpose of forming the resin coating layers 8 and 9, the constituent material, the forming method, and the like. In both cases, the thickness (average) is preferably about 1 to 100 μm, and more preferably about 1 to 30 μm. If the thickness of the resin coating layers 8 and 9 is too thin, the purpose of forming the resin coating layers 8 and 9 may not be sufficiently exhibited, and the resin coating layers 8 and 9 may be peeled off. Further, if the resin coating layers 8 and 9 are too thick, the physical characteristics of the wire body 10 may be affected, and the resin coating layers 8 and 9 may be peeled off.

  In the present invention, the outer peripheral surface (surface) of the wire body 10 is subjected to a treatment (roughening, chemical treatment, heat treatment, etc.) for improving the adhesion of the resin coating layers 8 and 9, or the resin coating layer. An intermediate layer that can improve the adhesion of 8, 9 can also be provided.

  It is preferable that the outer surface of at least the distal end portion of the guide wire 1 is coated with a hydrophilic material. In this embodiment, the hydrophilic material is coated on the outer peripheral surface of the guide wire 1 in the region from the distal end of the guide wire 1 to the vicinity of the proximal end of the tapered portion 16. As a result, the hydrophilic material is wetted to produce lubricity, the friction (sliding resistance) of the guide wire 1 is reduced, and the slidability is improved. Therefore, the operability of the guide wire 1 is improved.

  Examples of hydrophilic materials include cellulose-based polymer materials, polyethylene oxide-based polymer materials, and maleic anhydride-based polymer materials (for example, maleic anhydride copolymers such as methyl vinyl ether-maleic anhydride copolymer). Acrylamide polymer substances (for example, polyacrylamide, polyglycidyl methacrylate-dimethylacrylamide (PGMA-DMAA) block copolymer), water-soluble nylon, polyvinyl alcohol, polyvinylpyrrolidone and the like.

  In many cases, such a hydrophilic material exhibits lubricity by wetting (water absorption) and reduces frictional resistance (sliding resistance) with the inner wall of the catheter used together with the guide wire 1. Thereby, the slidability of the guide wire 1 is improved, and the operability of the guide wire 1 in the catheter becomes better.

Figure 5 is a longitudinal sectional view showing another embodiment of a gas guide wire. Hereinafter, the guide wire shown in FIG. 5 will be described, but the description of the same matters as those of the above-described guide wire shown in FIGS. 1 to 4 will be omitted, and differences will be mainly described. 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 ease of understanding, the length direction of the guide wire is shortened and the thickness direction of the guide wire is exaggerated and schematically illustrated. The ratio is different from the actual.

  The guide wire 1 shown in FIG. 5 is the same as the guide wire 1 shown in FIGS. 1 to 4 except that the coil 4 is not provided. That is, the guide wire 1 shown in FIG. 5 is formed by joining (connecting) the first wire 2 disposed on the distal end side and the second wire 3 disposed on the proximal end side of the first wire 2 by welding. The metal coating layer 6 is formed so as to fill the step 5 formed in the joint portion 14 between the first wire 2 and the second wire 3, having the wire body 10.

  A portion on the distal end side (the outer peripheral surface of the first wire 2) and a portion on the proximal end side (the outer peripheral surface of the second wire 3) of the wire body 10 are covered with resin coating layers 8 and 9, respectively.

  The purpose of forming the resin coating layers 8, 9 and the constituent materials are the same as described above. In the present embodiment, in particular, the resin coating layer 8 positioned on the distal end side of the guide wire 1 is made of the above-described flexible material (soft material, elastic material) and positioned on the proximal end side of the guide wire 1. The resin coating layer 9 is preferably made of a material that can reduce the friction described above. This is because it is possible to improve both slidability (operability) and safety. As a specific example in this case, there is a case where the resin coating layer 8 is made of polyurethane and the resin coating layer 9 is made of a fluorine-based resin (PTFE, ETFE or the like).

  Moreover, the resin coating layer 8 covers the first wire 2 without exposing the tip, and the tip of the resin coating layer 8 preferably has a rounded shape. Thereby, when the guide wire 1 is inserted into a body cavity such as a blood vessel, damage to the inner wall can be prevented more effectively, and safety can be improved.

  In the resin coating layer 8, fillers (particles) made of a contrasting material (such as the X-ray opaque material) may be dispersed, thereby forming a contrast portion.

  Further, it is preferable that a hydrophilic material is coated on at least the outer surface of the guide wire 1. In this embodiment, the hydrophilic material is coated on the outer peripheral surface of the guide wire 1 in the region from the distal end of the guide wire 1 to the vicinity of the proximal end of the tapered portion 16. As a result, the hydrophilic material is wetted to produce lubricity, the friction (sliding resistance) of the guide wire 1 is reduced, and the slidability is improved. Therefore, the operability of the guide wire 1 is improved.

  Further, the hydrophilic material may be formed on a part of the outer surface of the resin coating layer 8 or only on the entire outer surface. Specific examples of the hydrophilic material are the same as described above.

  6, 7, 8, and 9 are enlarged longitudinal sectional views showing other configuration examples in the vicinity of the joint portion 14 of the wire body 10 in the guide wire 1. Hereinafter, each structural example shown in these drawings will be described in order, but the description of the same matters as those of the above-described guide wire shown in FIGS. 1 to 4 will be omitted, and differences will be mainly described. For convenience of explanation, the right side in FIGS. 6 to 9 is referred to as “base end”, and the left side is referred to as “tip”. 6 to 9, the length direction of the wire body 10 is shortened and the thickness direction of the wire body 10 is exaggerated schematically for easy understanding. The ratio in the thickness direction is different from the actual one.

  In the wire main body 10 shown in FIG. 6, the outer diameter of the proximal end portion of the first wire 2 is constant, and the outer diameter of the distal end portion of the second wire 3 is constant (the taper portion 16 is not provided). The outer diameter D1 of the proximal end of the first wire 2 is set smaller than the outer diameter D2 of the distal end of the second wire 3. Other configurations are the same as those in the embodiment described with reference to FIG. 2 to FIG. 4 or FIG.

  The wire body 10 shown in FIG. 7 has a taper portion 17 in which the outer diameter of the proximal end portion of the first wire 2 is constant, and the outer diameter of the second wire 3 gradually increases in the forward direction. . The outer diameter D1 of the proximal end of the first wire 2 is set smaller than the outer diameter D2 of the distal end of the second wire 3. Other configurations are the same as those in the embodiment described with reference to FIG. 2 to FIG. 4 or FIG.

  The wire body 10 shown in FIG. 8 has a tapered portion 18 whose outer diameter gradually increases in the proximal direction at the proximal end portion of the first wire 2, and the outer diameter of the distal end portion of the second wire 3 is constant. (The taper portion 16 is not provided). The outer diameter D1 of the proximal end of the first wire 2 is set smaller than the outer diameter D2 of the distal end of the second wire 3. Other configurations are the same as those in the embodiment described with reference to FIG. 2 to FIG. 4 or FIG.

  The wire main body 10 shown in FIG. 9 is based on the configuration shown in FIG. 6 (the first wire 2, the second wire 3 and the structure in the vicinity of the joint portion 14 are the same), and the base of the second wire 3 is the same. A third wire 19 is further connected to the end by welding.

  The outer diameter of the proximal end portion of the second wire 3 and the outer diameter of the distal end portion of the third wire 19 are constant. The outer diameter D3 of the proximal end of the second wire 3 is set smaller than the outer diameter D4 of the distal end of the third wire 19. The proximal end of the second wire 3 and the distal end of the third wire 19 are joined by welding to form a joint portion 14, and the outer periphery of the joint portion 14 has an outer diameter D 3 and an outer diameter D 4. A metal coating layer 6 similar to the above is formed to fill the step 5 caused by the diameter difference.

  D2 and D3 may be the same or different. Although not shown, at least one of the second wire 3 and the third wire 19 may have, for example, a tapered portion similar to the tapered portion 16 or 17 at a necessary place.

  The constituent material of the 3rd wire 19 is not specifically limited, For example, stainless steel (For example, SUS304, SUS303, SUS316, SUS316L, SUS316J1, SUS316J1L, SUS405, SUS430, SUS434, SUS444, SUS429, SUS430F, SUS302, etc. Varieties), piano wires, cobalt-based alloys, alloys that exhibit pseudoelasticity (including superelastic alloys), and other metal materials can be used. The superelastic alloy described above is more preferable.

  The second wire 3 and the third wire 19 may be made of different materials, but are preferably made of the same or the same kind of metal material (the main metal material in the alloy is the same). Thereby, the joint strength of the joint part (welded part) 14 between the second wire 3 and the third wire 19 is further increased, and excellent torque transmission properties and the like are exhibited without causing separation or the like.

  In this case, each of the second wire 3 and the third wire 19 is preferably made of the superelastic alloy described above, and more preferably made of a Ni—Ti alloy. Thereby, the flexibility can be gradually increased toward the distal end portion of the wire main body 10 (from the third wire 19 to the first wire 2), and the proximal end portion of the wire main body 10, particularly the third wire 19 can be increased. Above, sufficient rigidity (bending rigidity, torsional rigidity) can be ensured. As a result, the guide wire 1 using the wire main body 10 shown in FIG. 9 obtains excellent pushability and torque transmission and secures good operability, while having good flexibility and resilience on the distal end side. As a result, the followability and safety of blood vessels, bile ducts and pancreatic ducts are improved.

  In addition, about the wire main body 10 shown in FIG. 9, the structure of those other than the above is the same as that of embodiment described based on above-mentioned FIG. 2-4 or FIG.

  In the present invention, any two or more configurations of the embodiments shown in FIGS. 1 to 9 described above may be combined.

10 and 11 are diagrams showing a use state in the case of using the gas guide wire 1 to PTCA surgery.

  10 and 11, 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 (lesion). 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. . The following operations are performed under fluoroscopy.

  As shown in FIG. 10, 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, inserted into the right coronary artery 50 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 joint 14 or the metal coating layer 6 between the first wire 2 and the second wire 3 of the guide wire 1 is located on the descending aorta side (in vivo) of the aortic arch 40.

  Next, as shown in FIG. 11, the distal end of the balloon catheter 20 inserted from the proximal end side of the guide wire 1 is protruded 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 201 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.

As described above, the guide wire manufacturing method of the present invention has been described based on the illustrated embodiments. However, the present invention is not limited to these, and each part constituting the guide wire exhibits the same function. It can be replaced with any configuration obtained. Moreover, arbitrary components may be added.

In addition, the use of the guide wire manufactured by the guide wire manufacturing method of the present invention is not limited to use in the above-described PTCA operation, and can be used for, for example, angiography, a transendoscopic procedure, and the like.

It is a longitudinal sectional view showing an embodiment of a gas guide wire. It is a longitudinal sectional view showing an enlarged vicinity of the joint portion of the wire body in moth guide wire. It is a longitudinal sectional view showing an enlarged vicinity of the joint portion of the wire body in moth guide wire. It is a longitudinal sectional view showing an enlarged vicinity of the joint portion of the wire body in moth guide wire. It is a longitudinal sectional view showing another embodiment of a gas guide wire. It is a longitudinal sectional view showing an enlarged another configuration example of the vicinity of the joint portion of the word ear body. It is a longitudinal sectional view showing an enlarged another configuration example of the vicinity of the joint portion of the word ear body. It is a longitudinal sectional view showing an enlarged another configuration example of the vicinity of the joint portion of the word ear body. It is a longitudinal sectional view showing an enlarged another configuration example of the vicinity of the joint portion of the word ear body. It is a schematic diagram for explaining an example of using the gas guide wire. It is a schematic diagram for explaining an example of using the gas guide wire.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Guide wire 10 Wire main body 2 1st wire 3 2nd wire 4 Coil 5 Level | step difference 6 Metal coating layer 61 Tapered part 8, 9 Resin coating layer 11, 12, 13 Fixing material 14 Joining part (welding part)
DESCRIPTION OF SYMBOLS 15 Outer diameter decreasing part 16, 17, 18 Tapered part 19 3rd wire 20 Balloon catheter 201 Balloon 30 Guiding catheter 40 Aortic arch 50 Right coronary artery 60 Right coronary artery opening 70 Vascular constriction part

Claims (6)

  Preparing a linear first wire made of a metal material and a linear second wire made of a metal material and having a distal end outer diameter larger than the outer diameter of the proximal end of the first wire; A first step of joining the proximal end of the first wire and the distal end of the second wire by welding;
  By removing and shaping a part of the solidified product of the molten metal generated by welding the first wire and the second wire in the first step, the base end of the first wire and the second wire And a second step of forming a metal coating layer that fills the step caused by the difference in the outer diameter of the tip. The guide wire manufacturing method according to claim 1, wherein the metal coating layer is formed by machining the solidified product of the molten metal. The method for manufacturing a guide wire according to claim 1, wherein the metal coating layer has a portion whose thickness gradually decreases in a distal direction. The guide wire manufacturing method according to any one of claims 1 to 3, wherein a distal end portion of the second wire is configured by a tapered portion whose outer diameter changes along the longitudinal direction. The guide wire manufacturing method according to claim 4, wherein the tapered portion has an outer diameter that gradually increases from a distal end toward a proximal end. The metal coating layer has a tapered portion whose outer diameter gradually decreases from the proximal end toward the distal end, and when the taper angle of the tapered portion is β and the taper angle of the tapered portion is α,
The guide wire manufacturing method according to claim 5, wherein a relationship of 0.5 ≦ β / α ≦ 2 is satisfied.

Images