JP5328835B2 - Guide wire manufacturing method - Google Patents

Description

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

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

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

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

  In order to improve such a defect, 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.

JP-A-63-171570

  The objective of this invention is providing the manufacturing method of the guide wire excellent in operativity and kink resistance.

Such an object is achieved by the present inventions (1) to (5) below.
(1) preparing a linear first wire composed of a Ni-Ti alloy and a linear second wire composed of stainless steel or a cobalt alloy;
Welding the first wire and the second wire to obtain a wire body having a weld;
Forming a coating layer covering the weld,
The coating layer is a material that can reduce friction on the surface in the vicinity of the welded portion, and is composed of a reaction-curing type silicone resin or a composite material containing the same, and the wire is formed in the step of forming the coating layer. A method of manufacturing a guide wire, wherein the guide wire is formed without being heated substantially when being coated on the main body.

(2) The guide wire manufacturing method according to (1) , wherein a distal end side coating layer is formed on a distal end side of the coating layer of the wire body.

(3) The guide wire manufacturing method according to (2) , wherein the tip side coating layer is formed by heating.

(4) The guide wire manufacturing method according to the above (2) or (3) , wherein a proximal end side coating layer is formed on the proximal side of the wire body with respect to the coating layer.

(5) The guide wire manufacturing method according to (4) , wherein the base end side coating layer is formed by heating.

  According to the present invention, by providing the first wire disposed on the distal end side and the second wire disposed on the proximal end side of the first wire and made of a material having a larger elastic modulus than the first wire. A guide wire having a distal end portion excellent in flexibility and a base end portion rich in rigidity and excellent in pushability, torque transmission property and followability can be configured.

  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.

  In addition, the outer periphery of the wire body is provided with a coating layer made of a material that can reduce friction on the surface near the welded portion so as to cover at least the welded portion, thereby providing kink resistance and sliding at the welded portion. Thus, the kink resistance of the entire guide wire is improved. In addition, even if a step, a burr, or the like is generated on the outer peripheral portion of the welded portion, the coating layer covers it, so that an adverse effect due to the step, a burr, or the like can be prevented or alleviated.

  In particular, since the coating layer is formed without being heated substantially when the wire body is coated, the guide layer is maintained while maintaining the bonding strength between the first wire and the second wire when the coating layer is formed. The wire as a whole has sufficient slidability and can exhibit excellent operability.

It is a longitudinal cross-sectional view which shows the structural example of the guide wire manufactured by the manufacturing method of the guide wire of this invention. It is a figure which shows the procedure which connects the 1st wire and 2nd wire in the guide wire shown in FIG. It is a longitudinal cross-sectional view which shows the other structural example of the guide wire manufactured by the manufacturing method of the guide wire of this invention. It is a longitudinal cross-sectional view which shows the other structural example of the guide wire manufactured by the manufacturing method of the guide wire of this invention. It is a longitudinal cross-sectional view which shows the other structural example of the guide wire manufactured by the manufacturing method of the guide wire of this invention. It is a longitudinal cross-sectional view which shows the structural example of the welding part vicinity in the guide wire manufactured by the manufacturing method of the guide wire of this invention. It is a longitudinal cross-sectional view which shows the structural example of the welding part vicinity in the guide wire manufactured by the manufacturing method of the guide wire of this invention. It is a schematic diagram for demonstrating the usage example of a guide wire. It is a schematic diagram for demonstrating the usage example of a guide wire.

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

  FIG. 1 is a longitudinal sectional view showing a configuration example of a guide wire manufactured by the guide wire manufacturing method of the present invention, and FIG. 2 is a procedure for connecting the first wire and the second wire in the guide wire shown in FIG. FIG. 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, the length direction of the guide wire is shortened and the thickness direction of the guide wire is exaggerated for the sake of clarity. The ratio is very different from the actual ratio (the same applies to FIGS. 3 to 5 described later).

  A guide wire 1 shown in FIG. 1 is a catheter guide wire used by being inserted into a catheter, and includes a first wire 2 disposed on the distal end side and a second wire disposed on the proximal end side of the first wire 2. A wire body 10 formed by connecting the wire 3 and a spiral coil 4 are provided. The total length of the guide wire 1 is not particularly limited, but is preferably about 200 to 5000 mm. Further, the outer diameter of the wire body 10 (the outer diameter of the portion where the outer diameter is constant) is not particularly limited, but is usually preferably about 0.2 to 1.2 mm.

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

  In the illustrated configuration, the first wire 2 has a constant outer diameter for a predetermined length from the base end, and the outer diameter gradually decreases from the middle toward the distal end. This portion is referred to as the outer diameter gradually decreasing portion 15. 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 safety, and prevent bending and the like.

  In the illustrated configuration, the outer diameter gradually decreasing portion 15 is formed on a part of the first wire 2, but the entire first wire 2 may constitute the outer diameter gradually decreasing portion 15. In addition, the taper angle (outer diameter reduction rate) 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.

  Further, the first wire 2 may have a portion with a constant outer diameter along the longitudinal direction in the middle of the outer diameter gradually decreasing portion 15 or on the tip side of the outer diameter gradually decreasing portion 15. For example, the first wire 2 has taper-shaped tapered portions whose outer diameters gradually decrease in the distal direction, and are formed at a plurality of locations along the longitudinal direction, and the outer diameter is long between the tapered portions and the tapered portions. A certain part may be formed along the direction. Even in such a case, the same effect as described above can be obtained.

  Unlike the illustrated configuration, the proximal end of the outer diameter gradually decreasing portion 15 is located in the middle of the second wire 3, that is, the outer diameter gradually decreasing portion 15 is a boundary between the first wire 2 and the second wire 3 (welded portion 14 ) May be used.

  The constituent material of the 1st wire 2 is not specifically limited, For example, various metal materials, such as stainless steel, can be used, Among them, the alloy (a superelastic alloy is included) which shows pseudoelasticity especially among these. preferable. More preferably, it is a superelastic alloy. 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 bendability can be obtained, followability to a complicatedly bent / bent blood vessel can be improved, more excellent operability can be obtained, and even if the first wire 2 repeats bending / bending deformation, Since the first wire 2 is not bent due to the resilience, it is possible to prevent the operability from being deteriorated due to the bending of 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 type alloy is excellent also in the adhesiveness of the coating layer 5 and the 2nd coating layer 6 mentioned later.

  The distal end of the second wire 3 is connected (connected) to the proximal end of the first wire 2 by welding. The second wire 3 is an elastic wire. Although the length of the 2nd wire 3 is not specifically limited, It is preferable that it is about 20-4800 mm.

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

  The constituent material (material) of the second wire 3 is not particularly limited, and stainless steel (for example, SUS304, SUS303, SUS316, SUS316L, SUS316J1, SUS316J1L, SUS405, SUS430, SUS434, SUS444, SUS429, SUS430F, SUS302, etc. All types), various metal materials such as piano wire, cobalt-based alloy, and pseudoelastic alloy can be used.

  Among these, the cobalt-based alloy has a high elastic modulus when used as a wire and has an appropriate elastic limit. For this reason, the 2nd wire 3 comprised by the cobalt type alloy has the outstanding outstanding torque transmission, and it is hard to produce problems, such as buckling. 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 as a constituent material of the second wire 3, the above-described effects become more remarkable. In addition, since an alloy having such a composition has plasticity even when deformed at room temperature, it can be easily deformed into a desired shape, for example, at the time of use. 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.

  Moreover, when stainless steel is used as the constituent material of the second wire 3, the guide wire 1 can obtain better pushability and torque transmission.

  In the present invention, the first wire 2 and the second wire 3 are preferably made of different alloys, and the first wire 2 is made of a material having a smaller elastic modulus than the constituent material of the second wire 3. Is preferred. As a result, the guide wire 1 has excellent flexibility at the distal end portion and abundant rigidity (bending rigidity, torsional rigidity) at the proximal end portion. As a result, the guide wire 1 obtains excellent pushability and torque transmission and secures good operability, while obtaining good flexibility and restoration on the distal end side, followability to blood vessels, and safety. Will improve.

  As a specific combination of the first wire 2 and the second wire 3, the first wire 2 is made of a superelastic alloy, and the second wire 3 is made of a Co—Ni—Cr alloy or stainless steel. It is particularly preferable to do this. Thereby, the effect mentioned above becomes further remarkable.

  In the illustrated configuration, the second wire has a substantially constant outer diameter over substantially the entire length, but may have a portion where the outer diameter changes in the longitudinal direction.

  In addition, it is preferable to use a Ni—Ti alloy as the superelastic alloy of the first wire 2 from the viewpoint of flexibility and resilience on the tip side.

  The coil 4 is a member formed by spirally winding a wire (thin wire), and is installed so as to cover 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 welded 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, and tungsten, or alloys containing these. In particular, when the guide wire 1 is made of an X-ray opaque material such as a noble metal, X-ray contrast can be obtained in the guide wire 1, and the guide wire 1 can be inserted into the living body while confirming the position of the tip under X-ray fluoroscopy. It is possible and preferable. 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 the blood vessel, the distal end surface of the fixing material 12 is preferably rounded.

  In the illustrated configuration, since the 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 illustrated configuration, 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, an ellipse or a quadrangle (particularly a rectangle). Also good.

  In the guide wire 1, 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 guidewire 1 The pushing force is reliably transmitted to the first wire 2.

  Moreover, it is preferable that the outer peripheral part of the welding part 14 is substantially smoothed, for example by methods <3>, <4> etc. which are mentioned later.

  In the illustrated configuration, the connection end surface 21 of the first wire 2 to the second wire 3 and the connection end surface 31 of the second wire 3 to the first wire 2 are substantially perpendicular to the axial direction (longitudinal direction) of both wires. It is a flat surface. Thereby, the process for forming the connection end surfaces 21 and 31 is very easy, and the above-described effect can be achieved without complicating the manufacturing process of the guide wire 1.

  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.

  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.

  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 where the first wire 2 and the second wire 3 are joined by butt seam welding are shown.

  In the procedure <1>, the first wire 2 and the second wire 3 fixed (attached) to a butt welder (not shown) are shown.

  In the procedure <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.

  In the procedure <3>, the protruding portion of the connection portion (welded portion 14) deformed by the pressure contact is removed (deleted). Thereby, the outer periphery of the welding part 14 is made substantially smooth. In addition, as for the removal method of a protrusion part, chemical processing, such as grinding, grinding | polishing, and etching, is mentioned, for example.

  Next, in step <4>, the outer diameter gradually decreasing portion 15 in which the outer diameter gradually decreases in the distal direction is formed by grinding or polishing the portion on the distal end side from the connection portion (welded portion 14) of the first wire 2. .

  When the base end of the outer diameter gradually decreasing portion 15 is set to the base end side from the welded portion 14, the procedure <4> may be performed by omitting the procedure <3>.

  The wire body 10 has a coating layer 5 that covers all or part of the outer peripheral surface (outer surface) thereof. The covering layer 5 can be formed for various purposes. As an example, the coating layer 5 reduces the friction (sliding resistance) of the guide wire 1 and improves the slidability, thereby improving the operability of the guide wire 1. May improve.

  For this purpose, the covering layer 5 is preferably made of a material that can reduce friction. 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. Further, since the sliding resistance of the guide wire 1 is lowered, when the guide wire 1 is moved and / or rotated in the catheter, the guide wire 1 is kinked (bent) or twisted, particularly in the vicinity of the welded portion. 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 achieved. And the operability of the guide wire 1 in the catheter becomes better. 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.

  When a fluororesin (or a composite material containing this) is used, the wire main body 10 is usually coated by a method such as baking or spraying while the resin material is heated. Thereby, the adhesiveness of the wire main body 10 and the coating layer 5 becomes especially excellent.

  Further, when the coating layer 5 is made of a silicone resin (or a composite material containing the same), the wire body can be formed without heating when the coating layer 5 is formed (covered on the wire body 10). Thus, the coating layer 5 that is firmly and firmly adhered to the coating 10 can be formed. That is, when the coating layer 5 is 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 coating layer 5 can be formed at room temperature. it can. Thus, by forming the coating layer 5 at room temperature, the coating can be easily performed, and the guide wire is maintained in a state in which the bonding strength between the first wire 2 and the second wire 3 in the welded portion 14 is sufficiently maintained. Can be operated.

  Other preferable examples of the material that can reduce friction include a hydrophilic material or a hydrophobic material. Of these, hydrophilic materials are particularly preferable.

  Examples of the hydrophilic material 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 materials (for example, polyacrylamide, block copolymer of polyglycidyl methacrylate-dimethylacrylamide (PGMA-DMAA)), 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.

  The location where the coating layer 5 is formed may be the entire length of the wire body 10 or a part in the longitudinal direction, but is preferably formed so as to cover the welded portion 14, that is, at the location including the welded portion 14. . Thereby, even if a step, a burr, or the like is generated on the outer peripheral portion of the welded portion 14, the covering layer 5 covers it, so that slidability can be secured. Moreover, since the coating layer 5 has a substantially uniform outer diameter, the slidability is further improved.

  The thickness of the coating layer 5 is not particularly limited, but usually the thickness (average) is preferably about 1 to 20 μm, and more preferably about 2 to 10 μm. If the thickness of the coating layer 5 is too thin, the purpose of forming the coating layer 5 may not be sufficiently exhibited, the peeling of the coating layer 5 may occur, and the thickness of the coating layer 5 is too thick. Then, the physical properties of the wire may be hindered, and the coating layer 5 may be peeled off.

  In the present invention, the outer peripheral surface (surface) of the wire body 10 can be subjected to a treatment (chemical treatment, heat treatment, etc.) for improving the adhesion of the coating layer 5 or the adhesion of the coating layer 5 can be improved. An intermediate layer can also be provided.

  Next, another configuration example of the guide wire manufactured by the guide wire manufacturing method of the present invention will be described with reference to FIG. 3, but the description of the same matters as the above-described guide wire is omitted, The difference will be mainly described.

  FIG. 3 is a longitudinal sectional view showing another configuration example of the guide wire manufactured by the guide wire manufacturing method of the present invention. The guide wire 1 shown in FIG. 3 has a distal end of the covering layer 5 at a position closer to the proximal end than the proximal end of the coil 4, and a second covering layer 6 different from the covering layer 5 on the distal end side of the covering layer 5. Is formed.

  The second covering layer 6 is provided so as to cover all or part of the coil 4. In the illustrated configuration, the second coating layer 6 covers the entire coil 4.

  Examples of the constituent material of the second coating layer 6 include the same materials as those mentioned for the coating layer 5 and other materials such as polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polyesters (PET, PBT). Etc.), polyamides, polyimides, polyurethanes, polystyrenes, polycarbonates, fluororesins, silicone resins, silicone rubbers, and other various elastomers (for example, thermoplastic elastomers such as polyamides and polyesters). The material of the second coating layer 6 may be the same as or different from the material of the coating layer 5.

  As described above, the constituent materials of the covering layer 5 and the second covering layer 6 are not particularly limited, but the covering layer 5 is made of a silicone resin (or a composite material containing the same) and the second covering layer. 6 is preferably composed of a fluororesin (or a composite material containing the same).

  Thereby, it can have both the advantage of the silicone resin mentioned above, and the advantage of a fluorine resin. That is, the guide layers are maintained while maintaining the bonding strength between the first wire 2 and the second wire 3 in the welded portion 14 by combining the constituent materials of the coating layer 5 and the second coating layer 6 as described above. The wire 1 as a whole has sufficient slidability and can exhibit excellent operability.

  Further, when the coating layer 5 is made of a silicone resin (or a composite material containing the same) and the second coating layer 6 is made of a fluorine-based resin (or a composite material containing the same), As described above, when forming the coating layer 5, it is preferable not to heat the wire body 10 and to heat the wire body 10 when coating the second coating layer 6. As a result, the above-described effects become more remarkable, and the adhesion between the second coating layer 6 and the wire body 10 is particularly excellent.

  Furthermore, when the coating layer 5 is made of a hydrophobic resin and the second coating layer 6 is made of a hydrophilic resin, the slidability in the catheter is particularly good and the passage through the blood vessel is good. Excellent.

  The thickness of the second coating layer 6 is not particularly limited, but usually the thickness (average) is preferably about 1 to 20 μm, more preferably about 2 to 10 μm. The thickness of the second coating layer 6 may be the same as or different from the thickness of the coating layer 5.

  The guide wire may not be provided with the coil 4, but in this case, the second coating layer 6 may or may not be provided at the same location.

  In the configuration shown in FIG. 3, the tip of the coating layer 5 and the base end of the second coating layer 6 are joined and both layers are formed continuously. The base end of the coating layer 6 may be spaced apart, or the coating layer 5 and the second coating layer 6 may partially overlap.

  FIG. 4 is a longitudinal sectional view showing another configuration example of the guide wire manufactured by the guide wire manufacturing method of the present invention. Hereinafter, a configuration example of the guide wire will be described with reference to this figure, but the description will focus on differences from the above-described guide wire, and description of similar matters will be omitted.

  In the guide wire 1 shown in FIG. 4, the first wire 2 has an outer diameter gradually decreasing portion 15 and an outer diameter gradually decreasing portion 16 provided on the proximal side from the outer diameter gradually decreasing portion 15. As described above, the first wire 2 (second wire 3) may have outer diameter gradually decreasing portions at a plurality of portions.

  In the guide wire 1 shown in FIG. 4, the second wire 3 has an outer diameter gradually decreasing portion 18 in the vicinity of the tip thereof. That is, the second wire 3 includes a first part provided in the vicinity of the distal end portion thereof and a second part provided on the proximal side from the first part and having higher rigidity than the first part. Have. Thereby, the effect that the elastic transition of the 1st wire 2 and the 2nd wire 3 changes smoothly is acquired.

  Further, in the configuration shown in the drawing, a protruding portion 17 protruding in the outer peripheral direction is formed on the welded portion 14. By forming such a protrusion 17, the bonding area between the first wire 2 and the second wire 3 is increased, and the bonding strength thereof is particularly high. As a result, the torsional torque and pushing force from the second wire 3 are more reliably transmitted to the first wire 2 in the guide wire 1.

  Further, by forming the protruding portion 17, for example, the welded portion 14 between the first wire 2 and the second wire 3 can be more easily visually recognized under X-ray fluoroscopy. As a result, by confirming the fluoroscopic image, the progress of the guide wire 1 and the catheter in the blood vessel can be easily and reliably grasped, which contributes to shortening of the operation time and improving safety. it can.

  Although the height of the protrusion part 17 is not specifically limited, It is preferable that it is 0.001-0.3 mm, and it is more preferable that it is 0.005-0.05 mm. If the height of the projecting portion 17 is less than the lower limit value, the above-described effects may not be sufficiently exhibited depending on the constituent materials of the first wire 2 and the second wire 3. On the other hand, when the height of the protruding portion 17 exceeds the upper limit value, the inner diameter of the lumen to be inserted into the balloon catheter is determined. In some cases, the diameter of the second wire 3 must be reduced, and it may be difficult to fully exhibit the physical properties of the second wire 3.

  The protrusion 17 as described above can be formed, for example, by gently shaping the protrusion 17 in the procedure <3> in the example of the joining procedure described above (see FIG. 2). In particular, when the second wire 3 has an outer diameter gradually decreasing portion (small cross-sectional area portion) 18 as in the guide wire 1 of this configuration example, the first wire 2 and the distal direction are The protrusion 17 can be formed by welding the second wire 3 having a gradually decreasing cross-sectional area (small cross-sectional area) where the cross-sectional area gradually decreases.

  The covering layer 5 covers the outer diameter gradually decreasing portion 18 and the protruding portion 17 and has a substantially uniform outer diameter. It should be noted that the “substantially uniform outer diameter” includes changes in the outer diameter that do not hinder use.

  In the present embodiment, the coating layer 5 covers the coil 4 to the first wire 2 and the second wire 3, but the coil 4 may be covered with a different material, for example, a hydrophilic material.

  FIG. 5 is a longitudinal sectional view showing another configuration example of the guide wire manufactured by the guide wire manufacturing method of the present invention. Hereinafter, a configuration example of the guide wire will be described with reference to this figure, but the description will focus on differences from the above-described guide wire, and description of similar matters will be omitted.

  In the guide wire 1 shown in FIG. 5, the coating layer 5 is formed so as to cover the vicinity of the welded portion 14 of the wire body 10, and a distal end side coating layer 6 ′ different from the coating layer 5 is formed on the distal end side of the coating layer 5. Further, a proximal side coating layer 7 different from the coating layer 5 is formed on the proximal side of the coating layer 5.

  As a constituent material of the front end side coating layer 6 ′, for example, those mentioned in the coating layer 5 and the second coating layer 6 can be used. The material of the distal end side coating layer 6 ′ may be the same as or different from the material of the coating layer 5 and the material of the proximal end side coating layer 7.

  The constituent material of the base end side coating layer 7 is not particularly limited, but the same materials as those described for the coating layer 5 and the tip side coating layer 6 'or other materials can be used. The material of the base end side coating layer 7 may be the same as or different from the material of the coating layer 5 and the material of the distal end side coating layer 6 ′.

  As described above, the base end side coating layer 7 may be made of any material, but is preferably made of a fluorine-based resin (or a composite material containing the same). Thereby, the frictional resistance (sliding resistance) between the guide wire 1 and the inner wall of the catheter can be reduced more effectively, and the slidability can be improved, and the operability of the guide wire 1 in the catheter is better. It will be something. 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.

  Moreover, as a specific combination of the constituent materials of the coating layer 5, the distal-side coating layer 6 ′, and the proximal-side coating layer 7, for example, the coating layer 5 is composed of a silicone resin (or a composite material including the same), The front end side coating layer 6 ′ is made of a fluorine-based resin (or a composite material containing this), and the base end side coating layer 7 is made of a fluorine-based resin (or a composite material containing this). Is preferred.

  Thereby, it can have both the advantage of the silicone resin mentioned above, and the advantage of a fluorine resin. That is, by combining the constituent materials of the coating layer 5, the distal-side coating layer 6 ′, and the proximal-side coating layer 7 as described above, the first wire 2 and the second wire 3 are joined in the welded portion 14. While maintaining the strength, the guide wire 1 as a whole has sufficient slidability and can exhibit excellent operability.

  Further, when the constituent materials of the coating layer 5, the distal-side coating layer 6 ′, and the proximal-side coating layer 7 are the above combinations, as described above, when the coating layer 5 is formed, the wire body It is preferable to heat 10 when heating the tip side coating layer 6 ′ and the base side coating layer 7 without heating. As a result, the above-described effects become more remarkable, and the adhesion between the distal end side coating layer 6 ′ and the wire body 10 and the adhesion between the proximal side coating layer 7 and the wire body 10 are particularly excellent. It becomes.

  Further, the thickness of the front end side coating layer 6 ′ is not particularly limited, but usually the thickness (average) is preferably about 1 to 20 μm, more preferably about 2 to 10 μm. The thickness of the distal-side coating layer 6 ′ may be the same as or different from the thickness of the coating layer 5 and the thickness of the proximal-side coating layer 7.

  Moreover, the thickness of the base end side coating layer 7 is not particularly limited, but usually the thickness (average) is preferably about 1 to 20 μm, and more preferably about 2 to 10 μm. The thickness of the base end side coating layer 7 may be the same as or different from the thickness of the coating layer 5 and the thickness of the distal end side coating layer 6 ′.

  Further, in the configuration shown in FIG. 5, the base end of the coating layer 5 and the tip of the base end side coating layer 7 are joined to form both layers continuously. The tip of the side coating layer 7 may be spaced apart, or the coating layer 5 and the proximal side coating layer 7 may partially overlap.

  In the configuration shown in FIG. 5, the tip side coating layer 6 ′ also covers the coil 4, but the coil 4 may be covered with a different material, for example, a hydrophilic material.

  FIG. 6 and FIG. 7 are longitudinal sectional views showing other configuration examples in the vicinity of the welded portion in the guide wire manufactured by the guide wire manufacturing method of the present invention. Hereinafter, description will be made sequentially.

  As shown in FIG. 6, a coating layer 5 ′ is formed on the outer periphery of the wire body 10 in the vicinity of the welded portion 14 so as to cover the outer periphery of the welded portion 14 (so as to straddle the welded portion 14). A distal end side covering layer 6 ′ and a proximal end side covering layer 7 similar to those described above are formed on the distal end side and the proximal end side of the layer 5 ′, respectively. In this case, the thickness of the coating layer 5 ′ is substantially uniform along the axial direction.

  The covering layer 5 ′ functions as a reinforcing layer that reinforces the welded portion 14. By providing such a covering layer 5 ′, the welding strength of the welded portion 14 is improved, and when a torsional torque or a pushing force is applied from the second wire 3 to the first wire 2, Damage is prevented and the torsional torque and pushing force are transmitted more reliably.

  Examples of the constituent material of the coating layer 5 ′ include various metal materials and various hard resin materials, and metal materials are particularly preferable.

  Moreover, it is preferable that the constituent material of the coating layer 5 ′ is made of a material having the same rigidity as that of the material constituting the first wire 2 as described above or a smaller rigidity (large flexibility). Thereby, the advantage by the above-mentioned reinforcement effect can be acquired, ensuring the softness | flexibility of the welding part 14 vicinity, and the restoring property with respect to a bending sufficiently.

  The welding part 14 shown in FIG. 7 is formed with a protruding part 17 protruding in the outer peripheral direction. The effects of the formation of the protrusions 17, the conditions of the protrusions 17, the formation method, and the like are the same as described above.

  A coating layer 5 similar to the above is provided on the outer periphery of the wire body 10. In this case, the covering layer 5 is formed so as to straddle the protruding portion 17, that is, straddle the welded portion 14, and the thickness of the covering layer 5 is substantially uniform from the proximal end portion to the distal end portion of the protruding portion 17. It is. By setting it as such a structure, the softness | flexibility of the welding part 14 vicinity and the restoring property with respect to a bending can fully be ensured.

  In the configuration shown in FIGS. 4, 5, and 7, the projecting portion 17 has a substantially circular arc shape on one side (upper side in each figure) and on the opposite side (lower side in each figure) of the longitudinal section. None, the welded portion 14 is located at the maximum outer diameter portion of the protruding portion 17. Thereby, the area of the welding surface of the welding part 14 can be taken large, and there exists an advantage that higher bond strength (welding strength) is obtained.

  However, it goes without saying that the shape of the protruding portion 17 and the position of the welded portion 14 relative to the protruding portion 17 are not limited to this. For example, the protruding portion 17 may have a non-circular (non-arc-shaped) shape such as a trapezoidal shape or a triangular shape, for example, on one side and the opposite side in the longitudinal section. Further, the protruding portion 17 may have an asymmetric shape between the proximal end side and the distal end side with respect to the welding surface (connection end surfaces 21, 31) of the welded portion 14. In addition, the protrusion 17 has an axial position of the welding surface of the welded portion 14 with respect to the protrusion 17, not the central portion as shown in FIGS. 4, 5, and 7, but the proximal end side (the second wire 3 side). ) Or at a position biased toward the tip side (first wire 2 side). By adopting such a configuration, it is possible to prevent or alleviate stress concentration on the welded portion 14, and thus when a torsional torque or a pushing force is applied from the second wire 3 to the first wire 2, the welded portion. It is possible to more reliably prevent the welded portion 14 from being damaged due to stress concentration on the surface 14.

  Moreover, as the coating layer 5 which coat | covers the protrusion part 17, the reinforcement layer demonstrated in embodiment shown in FIG. 6 may be sufficient. If it coat | covers with a metal material, the joint strength of the protrusion part 17 can be improved. For example, a relatively thin metal tube can be inserted to the vicinity of the protruding portion 17 and pressure can be applied from the outside to form the coating layer 5 firmly adhered to the protruding portion 17.

  FIG. 8 and FIG. 9 are diagrams each showing a use state when the guide wire 1 is used for PTCA.

  8 and 9, reference numeral 40 denotes an aortic arch, reference numeral 50 denotes a right coronary artery of the heart, reference numeral 60 denotes a right coronary artery opening, and reference numeral 70 denotes a vascular stenosis. Reference numeral 30 is a guiding catheter for reliably guiding the guide wire 1 from the femoral artery to the right coronary artery, and reference numeral 20 is a balloon catheter for constriction portion expansion having a balloon 201 that can be expanded and contracted at its distal end. .

  As shown in FIG. 8, the distal end of the guide wire 1 is projected from the distal end of the guiding catheter 30 and inserted into the right coronary artery 50 through the right coronary artery opening 60. Further, the guide wire 1 is advanced and inserted into the right coronary artery from the distal end, and stopped at a position where the distal end exceeds the vascular stenosis 70. Thereby, the passage of the balloon catheter 20 is secured. At this time, the welded portion 14 of the guide wire 1 is located near the base of the aortic arch 40 (in vivo).

  Next, as shown in FIG. 9, 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 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 illustrated example of the configuration of the guide wire has been described. However, the present invention is not limited to these, and each component constituting the guide wire is replaced with an arbitrary configuration that can exhibit the same function. be able to. Moreover, arbitrary components may be added.

  In addition, the guide wire may be a combination of any two or more configurations (features) of the configuration examples.

DESCRIPTION OF SYMBOLS 1 Guide wire 10 Wire body 2 1st wire 21 Connection end surface 3 2nd wire 31 Connection end surface 4 Coil 5 Covering layer 5 'Covering layer (reinforcing layer)
6 Second coating layer 6 ′ Tip side coating layer 7 Base end side coating layer 11, 12, 13 Fixing material 14 Welding portion 15 Outer diameter gradually decreasing portion 16 Outer diameter gradually decreasing portion 17 Projecting portion 18 Outer diameter gradually decreasing portion (small cross-sectional area) Part)
20 balloon catheter 201 balloon 30 guiding catheter 40 aortic arch 50 right coronary artery 60 right coronary artery opening 70 vascular stenosis

Claims (5)

Preparing a linear first wire composed of a Ni-Ti alloy and a linear second wire composed of stainless steel or a cobalt alloy;
Welding the first wire and the second wire to obtain a wire body having a weld;
Forming a coating layer covering the weld,
The coating layer is a material that can reduce friction on the surface in the vicinity of the welded portion, and is composed of a reaction-curing type silicone resin or a composite material containing the same, and the wire is formed in the step of forming the coating layer. A method of manufacturing a guide wire, wherein the guide wire is formed without being heated substantially when being coated on the main body. The guide wire manufacturing method according to claim 1 , wherein a tip side coating layer is formed on a tip side of the wire body from the coating layer. The guide wire manufacturing method according to claim 2 , wherein the tip side coating layer is formed by heating. The guide wire manufacturing method according to claim 2 , wherein a proximal end side coating layer is formed on a proximal end side of the wire body with respect to the covering layer. The guide wire manufacturing method according to claim 4 , wherein the base end side coating layer is formed by heating.

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