JP4138467B2 - Guide wire - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a guide wire, and particularly to a guide wire used when a catheter is introduced into a body cavity such as a blood vessel.
[0002]
[Prior art]
The guide wire can be used for the treatment of a site where surgical operation is difficult, such as PTCA (Percutaneous Transluminal Coronary Angioplasty), or for the purpose of minimally invasive to the human body, Used to guide catheters used for examinations such as angiography. A guide wire used for PTCA surgery is inserted to the vicinity of the target vascular stenosis portion together with the balloon catheter with the tip of the guide wire protruding from the tip of the balloon catheter. Guide to near.
[0003]
The blood vessel is intricately curved, and the guide wire used to insert the balloon catheter into the blood vessel has 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.
[0004]
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.
[0005]
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).
[0006]
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.
[0007]
[Patent Document 1]
JP-A-63-171570
[0008]
[Problems to be solved by the invention]
An object of the present invention is to provide a guide wire excellent in operability, in particular, a guide wire excellent in kink resistance, pushability (pushability) and torque transmission.
[0009]
[Means for Solving the Problems]
  The purpose is as follows (1)~ (8)This is achieved by the present invention.
[0010]
  (1) A guide having a wire body including a welded portion formed by connecting a linear first wire disposed on the distal end side and a second wire disposed on the proximal end side of the first wire by welding. A wire,
The second wire is provided in the vicinity of the weld, and has a first portion having a cross-sectional area smaller than a cross-sectional area of the base end portion of the first wire, and a base end side of the first portion. And a second part having a rigidity higher than that of the first part,
  The first wire is made of a Ni-Ti alloy showing pseudoelasticity, and the second wire is made of a Co-Ni-Cr alloy,
  A guide wire comprising a coating layer made of a resin material provided to cover the weld and capable of reducing friction.
[0011]
  (2) The Co—Ni—Cr alloy is an alloy having a composition of 28 to 50 wt% Co-10 to 30 wt% Ni-10 to 30 wt% Cr—balance Fe, or a part of each of these elements is other The guide wire according to the above (1), which is an alloy substituted with an element (substitution element).
  (3) The guide wire according to (1) or (2), wherein the first portion is a cross-sectional area gradually decreasing portion in which a cross-sectional area gradually decreases toward a tip of the second wire.
  (4) The guide wire according to any one of (1) to (3), wherein a protruding portion that protrudes in an outer peripheral direction is formed on the welded portion.
  (5) The guide wire according to (4), wherein the protrusion has a height satisfying a range of 0.01 to 0.3 mm.
  (6) In the above (4) or (5), the coating layer constitutes the surface of the guide wire, and the surface of the guide wire has a portion protruding along the curve of the protruding portion. Guide wire as described.
[0012]
  (7) The guide wire according to any one of (1) to (6), wherein the coating layer is formed of a reaction-curable silicone resin that can be formed at room temperature or a composite material including the same.
[0013]
  (8)  The coating layer is made of a fluororesin(1) to (6)A guide wire according to any one of the above.
[0016]
It is preferable that the welding of the first wire and the second wire is performed by butt resistance welding.
[0017]
It is preferable that a protruding portion that protrudes in the outer circumferential direction is formed in a welded portion between the first wire and the second wire.
[0018]
It is preferable that the second wire has a portion in the vicinity of the welded portion whose cross-sectional area is smaller than the cross-sectional area of the proximal end portion of the first wire.
[0020]
  The coating layer is,parentIt is preferably composed of an aqueous material.
[0021]
  in frontThe thickness of the coating layer is preferably 1 to 20 μm.
[0022]
It is preferable to have a second coating layer provided on the tip side of the coating layer and made of a material different from that of the coating layer.
[0023]
The coating layer is formed without substantially heating the wire body when coating the guide wire body, and the second coating layer covers the guide wire body. In this case, it is preferably formed by heating.
[0024]
The second coating layer is preferably made of a material that can reduce friction.
The second coating layer is preferably made of a fluorine-based resin or a hydrophilic material.
The thickness of the second coating layer is preferably 1 to 20 μm.
[0025]
It is preferable to have a third coating layer provided on the base end side of the coating layer and made of a material different from that of the coating layer.
[0026]
The coating layer is formed without substantially heating the wire body when coating the guide wire body, and the third coating layer covers the guide wire body. In this case, it is preferably formed by heating.
[0027]
The third coating layer is preferably made of a material that can reduce friction.
The third coating layer is preferably made of a fluororesin or a hydrophilic material.
The thickness of the third coating layer is preferably 1 to 20 μm.
[0028]
The wire body preferably has at least one outer diameter gradually decreasing portion (tapered portion) whose outer diameter gradually decreases in the distal direction.
[0029]
It is preferable that the outer diameter gradually decreasing portion is provided in the first wire.
It is preferable that the outer diameter gradually decreasing portion is provided on the second wire.
[0030]
It is preferable that the outer diameter gradually decreasing portion is provided in the vicinity of the welded portion of the second wire.
[0031]
The outer diameter gradually decreasing portion is preferably provided in each of the first wire and the second wire.
[0032]
Moreover, it is preferable to have a spiral coil that covers at least the tip side portion of the first wire.
Moreover, it is preferable that the said welding part is located in the base end side rather than the base end of the said coil.
[0033]
Moreover, it is preferable that the 2nd coating layer is provided so that at least one part of the said coil may be covered.
[0034]
Moreover, it is preferable that the connection end surface of the said 1st wire and the said 2nd wire is respectively substantially perpendicular | vertical with respect to the axial direction of both wires.
[0035]
Moreover, it is preferable that the said protrusion part is formed when welding the said 1st wire and the said 2nd wire.
[0036]
Moreover, it is preferable that the said welding part is used so that it may become a position in a biological body.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the guide wire of the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.
[0038]
FIG. 1 is a longitudinal sectional view showing a first embodiment of the guide wire of the present invention, and FIG. 2 is a diagram showing a procedure for connecting the first wire and the second wire in the guide wire shown in 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).
[0039]
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.
[0040]
The first wire 2 is a wire having elasticity (flexibility). Although the length of the 1st wire 2 is not specifically limited, It is preferable that it is about 20-1000 mm.
[0041]
In the present embodiment, the first wire 2 has a constant outer diameter for a predetermined length from the proximal end, and the outer diameter gradually decreases in the distal direction from the middle. This portion is referred to as an outer diameter gradually decreasing portion (tapered 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.
[0042]
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 where the taper angle (reduction rate of outer diameter) is relatively large and a portion where the taper angle is relatively small are alternately formed a plurality of times, or the taper angle is continuously along the longitudinal direction of the wire. It may have a part that changes. In addition, a plurality of outer diameter gradually decreasing portions may be formed on the first wire 2.
[0043]
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.
[0044]
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.
[0045]
The constituent material of the first wire 2 is an alloy (including a superelastic alloy) exhibiting pseudoelasticity, and a superelastic alloy is particularly preferable. 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.
[0046]
The preferred composition of the superelastic alloy is Ni-Ti alloy such as Ni-Ti alloy of 49 to 52 atomic% Ni, Cu-Zn alloy of 38.5 to 41.5 wt% Zn, 1 to 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. This is because the distal end side flexibility and restoring property of the guide wire 1 can be made particularly excellent. 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.
[0047]
Alloys exhibiting pseudoelasticity include any shape of a stress-strain curve caused by tension, including those that can measure the transformation point such as As, Af, Ms, and Mf remarkably, and those that cannot be measured. Anything that is deformed (distorted) and returns almost to its original shape by removing the stress is included.
[0048]
The distal end of the second wire 3 is connected (connected) to the proximal end of the first wire 2 by welding. The 2nd wire 3 is comprised with the wire which has elasticity (flexibility). Although the length of the 2nd wire 3 is not specifically limited, It is preferable that it is about 20-4800 mm.
[0049]
The second wire 3 is preferably 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.
[0050]
Such a constituent material (material) of the second wire 3 is a cobalt-based alloy. 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. Further, when the cobalt-based alloy is welded to the superelastic alloy constituting the first wire 2, there is an advantage that the welding strength is high.
[0051]
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.
[0052]
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 each of these elements is another element ( Alloys substituted with a substitution element) 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, Cr, and Fe is included, the content (of the entire substituted element) is preferably 30 wt% or less.
[0053]
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. More preferably, it is a Co—Ni—Cr—Mo alloy.
[0054]
The specific composition of the Co-Ni-Cr alloy is, 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.
[0055]
In the present invention, by making the constituent materials of the first wire 2 and the second wire 3 as described above, the distal end portion has excellent flexibility and the proximal end portion is rigid (bending rigidity, torsion). (Rigidity) rich. 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.
[0056]
Further, in the present invention, when the first wire 2 and the second wire 3 made of the above materials are welded, since the two wires have good compatibility, they are firmly joined, so that the operability of the guide wire 1 is excellent. be able to.
[0057]
The most preferable combination of the constituent materials of the first wire 2 and the second wire 3 is that the first wire 2 is a Ni—Ti alloy, and the second wire 3 is a Co—Ni—Cr alloy or a Co—Ni—Cr—Mo alloy. It is an alloy. Thereby, the effect mentioned above becomes still more remarkable.
[0058]
In the illustrated configuration, the second wire has a substantially constant outer diameter over substantially the entire length, but at least a portion where the outer diameter changes along the longitudinal direction (for example, the aforementioned gradually decreasing outer diameter portion). You may have one place.
[0059]
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.
[0060]
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.
[0061]
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.
[0062]
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.
[0063]
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.
[0064]
In the case of the present embodiment, the coil 4 has a circular cross section of the wire. However, the present invention is not limited to this, and the cross section of the wire is, for example, elliptical or quadrangular (particularly rectangular). Also good.
[0065]
In the guide wire 1, the first wire 2 and the second wire 3 are connected (fixed) 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 (bonding strength). The pushing force is reliably transmitted to the first wire 2. In particular, by making the constituent materials of the first wire 2 and the second wire 3 as described above, higher bonding strength can be obtained even when welding a Ni—Ti alloy and stainless steel.
[0066]
Even if the outer peripheral portion of the welded portion 14 is substantially smooth, for example, by procedures (3) and (4) described later, the projecting portion 17 is left by omitting the procedure (3). It may be said. The configuration shown in FIG. 1 is the former.
[0067]
In this embodiment, the connection end surface 21 of the first wire 2 with respect to the second wire 3 and the connection end surface 31 of the second wire 3 with respect to the first wire 2 are substantially perpendicular to the axial direction (longitudinal direction) of both wires. It is 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.
[0068]
Note that, unlike the illustrated configuration, the connection end surfaces 21 and 31 may be inclined with respect to a plane perpendicular to the axial direction (longitudinal direction) of both wires, and have a concave or convex surface or a shape having a step. It may be.
[0069]
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 joint strength is obtained.
[0070]
Hereinafter, with reference to FIG. 2, the procedure in the case of joining the 1st wire 2 and the 2nd wire 3 by butt seam welding which is an example of butt resistance welding is demonstrated. In the figure, procedures (1) to (4) in the case of joining the first wire 2 and the second wire 3 by butt seam welding are shown.
[0071]
In the procedure (1), the first wire 2 and the second wire 3 fixed (attached) to a butt welder (not shown) are shown.
[0072]
In step (2), the first wire 2 and the second wire 3 are connected to the proximal end side connection end surface 21 of the first wire 2 and the distal end of the second wire 3 while a predetermined voltage is applied by a butt welder. The contact end surface 31 on the side is brought into pressure contact. By this pressure contact, a molten layer is formed at the contact portion, and the first wire 2 and the second wire 3 are firmly connected.
[0073]
In step {circle around (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.
[0074]
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. .
[0075]
When the base end of the outer diameter gradually decreasing portion 15 is set to the base end side from the welded portion 14, step (3) may be omitted and step (4) may be performed.
[0076]
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.
[0077]
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.
[0078]
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.
[0079]
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.
[0080]
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.
[0081]
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 can be reliably and firmly adhered to the coating layer 10. 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 is formed at room temperature. Can do. As described above, by forming the coating layer 5 at room temperature, the coating can be easily performed, and the guide wire is operated in a state where the bonding strength between the first wire 2 and the second wire 3 in the welded portion 14 is maintained. Can do.
[0082]
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.
[0083]
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.
[0084]
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.
[0085]
Such a layer of hydrophilic material (or hydrophobic material) can also be provided as an upper layer of the coating layer 5 made of fluorine-based resin, silicone resin, or the like.
[0086]
The formation location (formation region) of the covering layer 5 may be the entire length of the wire body 10 or a part in the longitudinal direction, but is formed so as to cover the welded portion 14, that is, at a location including the welded portion 14. preferable.
[0087]
In the configuration shown in FIG. 1, the distal end of the coating layer 5 is located in the middle of the first wire 2 (on the outer diameter gradually decreasing portion 15), but not limited to this, the coating layer 5 is further extended to the distal end side. The coil 4 and the fixing material 12 may be formed so as to cover the tips.
[0088]
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 depending on the material, the coating layer 5 may be peeled off.
[0089]
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.
[0090]
FIG. 3 is a longitudinal sectional view showing a second embodiment of the guide wire of the present invention. Hereinafter, the second embodiment of the guide wire of the present invention will be described with reference to this figure, but the description will focus on the differences from the first embodiment described above, and description of similar matters will be omitted.
[0091]
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.
[0092]
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. That is, the second coating layer 6 is formed continuously from the tip of the coating layer 5 and covers up to the tip of the fixing material 12.
[0093]
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.
[0094]
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).
[0095]
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.
[0096]
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.
[0097]
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.
[0098]
In addition, although the guide wire of this invention may not provide the coil 4, in this case, it is not necessary to provide the said 2nd coating layer 6 in the same location.
[0099]
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 to form both layers 5, 6. The base end of the second coating layer 6 may be separated, or the coating layer 5 and the second coating layer 6 may partially overlap. Any of the overlapping portions of the layers 5 and 6 may be an upper layer. Furthermore, the coating layer 5 and the second coating layer 6 may be partially mixed (fused).
[0100]
FIG. 4 is a longitudinal sectional view showing a third embodiment of the guide wire of the present invention. Hereinafter, a third embodiment of the guide wire of the present invention will be described with reference to this drawing, but the description will focus on the differences from the above-described embodiment, and the description of the same matters will be omitted.
[0101]
In the guide wire 1 of the present embodiment, 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.
[0102]
Moreover, in the guide wire 1 of this embodiment, the 2nd wire 3 has the cross-sectional area gradually decreasing part (outer diameter gradually decreasing part: small cross-sectional area part) 18 in the vicinity of the front-end | tip. 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 transition of elasticity between the first wire 2 and the second wire 3 becomes smoother is obtained.
[0103]
The cross-sectional area gradually decreasing portion 18 of the second wire 3 has its cross-sectional area gradually decreasing toward the protruding portion 17 described below. In the configuration shown in the figure, the cross section is circular and has a tapered shape in which the outer diameter gradually decreases toward the protrusion 17. However, the cross-sectional shape of the cross-sectional area gradually decreasing portion 18 is not limited to a circle, and may be a polygon such as a rectangle, a hexagon, an octagon, an ellipse, or any other shape.
[0104]
In the present embodiment, the welded portion 14 is formed with a protruding portion 17 that protrudes in the outer peripheral direction. 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.
[0105]
In the configuration shown in the figure, the surface of the guide wire 1 is flat in the vicinity of the welded portion 14. For example, the guide wire 1 has a portion that protrudes from the surface of the guide wire 1 along the curvature of the protruding portion 17. There may be. In this case, the contact area with the inner wall of the catheter used together with the guide wire 1 can be reduced. Thereby, the frictional resistance at the time of moving the guide wire 1 and the catheter relatively is reduced, and the slidability is improved. As a result, the operability of the guide wire 1 in the catheter is good.
[0106]
Although the height of the protrusion part 17 is not specifically limited, It is preferable that it is 0.01-0.3 mm, and it is more preferable that it is 0.01-0.05 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, so that the outside of the second wire 3 on the proximal end side is compared with the height of the protruding portion 17. 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.
[0107]
The protrusion 17 as described above can be formed, for example, by gently shaping the protrusion in step (3) in the above-described example of the joining procedure (see FIG. 2). In particular, when the second wire 3 has a cross-sectional area gradually decreasing portion (small cross-sectional area portion) 18 as in the guide wire 1 of the present embodiment, the first wire 2 and the distal direction are formed by the method described above. 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.
[0108]
FIG. 5 is a longitudinal sectional view showing a fourth embodiment of the guide wire of the present invention. Hereinafter, the fourth embodiment of the guide wire of the present invention will be described with reference to this drawing. However, the difference from the above-described embodiment will be mainly described, and description of similar matters will be omitted.
[0109]
In the guide wire 1 of the present embodiment, the coating layer 5 is formed so as to cover the vicinity of the welded portion 14 of the wire body 10, and a second coating layer 6 different from the coating layer 5 is formed on the distal end side of the coating layer 5. Further, a third coating layer 7 different from the coating layer 5 is formed on the base end side of the coating layer 5.
[0110]
Although it does not specifically limit as a constituent material of the 3rd coating layer 7, The same thing as what was mentioned by the said coating layer 5 and the 2nd coating layer 6 and others are mentioned. The material of the third coating layer 7 may be the same as or different from the material of the coating layer 5 and the material of the second coating layer 6.
[0111]
As described above, the third 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.
[0112]
Moreover, as a specific combination of the constituent materials of the coating layer 5, the second coating layer 6, and the third coating layer 7, for example, the coating layer 5 is composed of a silicone resin (or a composite material including the same), The second coating layer 6 is made of a fluorine-based resin (or a composite material containing the same), and the third coating layer 7 is made of a fluorine-based resin (or a composite material containing the same). Is preferred.
[0113]
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 second coating layer 6, and the third 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.
[0114]
When the constituent materials of the covering layer 5, the second covering layer 6, and the third covering layer 7 are the above combinations, as described above, when forming the covering layer 5, the wire body When 10 is not heated and the second coating layer 6 and the third coating layer 7 are coated, it is preferable to heat them. As a result, the above-described effects become more remarkable, and the adhesion between the second coating layer 6 and the wire body 10 and the adhesion between the third coating layer 7 and the wire body 10 are particularly excellent. It becomes.
[0115]
Moreover, the thickness of the 3rd coating layer 7 is although it does not specifically limit, Usually, it is preferable that thickness (average) is about 1-20 micrometers, and it is more preferable that it is about 2-10 micrometers. The thickness of the third coating layer 7 may be the same as or different from the thickness of the coating layer 5 and the thickness of the second coating layer 6.
[0116]
In the configuration shown in FIG. 5, the base end of the covering layer 5 and the tip end of the third covering layer 7 are joined and both layers are formed continuously. The tip of the coating layer 7 may be spaced apart, or the coating layer 5 and the third coating layer 7 may partially overlap. Any of the overlapping portions of the layers 5 and 7 may be an upper layer. Furthermore, the coating layer 5 and the third coating layer 7 may be partially mixed (fused).
[0117]
Further, the second coating layer 6 and the third coating layer 7 may cover the entire outer peripheral surface of the coating layer 5 (a configuration in which the outer surface of the coating layer 5 is not exposed). In this configuration, when the second coating layer 6 and the third coating layer 7 are made of the same material (for example, fluorine-based resin), there is no boundary between the second coating layer 6 and the third coating layer 7. It may be recognized as one layer.
[0118]
FIG. 6 and FIG. 7 are diagrams showing a use state when the guide wire 1 of the present invention is used for PTCA.
[0119]
6 and 7, 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. .
[0120]
As shown in FIG. 6, the distal end of the guide wire 1 is protruded 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).
[0121]
Next, as shown in FIG. 7, 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.
[0122]
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.
[0123]
The guide wire of the present invention has been described above with respect to the illustrated embodiments. However, the present invention is not limited to these embodiments, and each part of the guide wire has an arbitrary configuration that can exhibit the same function. Can be substituted for Moreover, arbitrary components may be added.
[0124]
【The invention's effect】
As described above, according to the present invention, a guide wire having a tip portion excellent in flexibility and a base end portion rich in rigidity, and excellent in kink resistance, push-in property, torque transmission property and follow-up property. Is obtained.
[0125]
Further, since the first wire and the second wire are connected by welding, the connecting portion (welded portion) has a high bonding strength. In particular, the first wire on the distal end side is made of a superelastic alloy and the second wire on the proximal end side. By configuring the wire with a cobalt-based alloy, the distal end portion has excellent flexibility, and the proximal end portion is rich in rigidity (bending rigidity, torsional rigidity), and these physical properties are well balanced. In addition, since the bonding strength of the welded portion between the first wire and the second wire is high, the pushing force and the torsion torque can be reliably transmitted from the proximal end side to the distal end side, and excellent pushability and In addition to exhibiting torque transferability, good flexibility and resilience are obtained on the distal end side where these forces are transmitted, and blood vessel followability and safety are improved.
[0126]
Further, when the coating layer is made of a silicone-based resin, the guide wire as a whole is sufficiently slid while maintaining the bonding strength between the first wire and the second wire when the coating layer is formed. And exhibit excellent operability.
[0127]
Further, when the coating layer is made of a material that can reduce friction, the slidability of the guide wire in the catheter or the like is improved, and the operability of the guide wire can be improved. By reducing the sliding resistance of the guide wire, it is possible to more reliably prevent kinking (bending) and twisting of the guide wire, especially kinking and twisting near the welded part. Can be maintained.
[0128]
Also, by forming a second coating layer or a third coating layer different from the coating layer, a portion having a property different from that of the coating layer, for example, a portion having a higher sliding resistance than the coating layer is provided. Therefore, the versatility of the guide wire is widened for the surgeon.
[0129]
Further, by forming the protruding portion in the welded portion, it is possible to further increase the joining strength of the connecting portion (welded portion), and more reliably transmit the torsional torque and the pushing force from the second wire to the first wire. It becomes possible.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a first embodiment of a guide wire of the present invention.
FIG. 2 is a diagram showing a procedure for connecting a first wire and a second wire in the guide wire of the present invention.
FIG. 3 is a longitudinal sectional view showing a second embodiment of the guide wire of the present invention.
FIG. 4 is a longitudinal sectional view showing a third embodiment of the guide wire of the present invention.
FIG. 5 is a longitudinal sectional view showing a fourth embodiment of the guide wire of the present invention.
FIG. 6 is a schematic view for explaining an example of use of the guide wire of the present invention.
FIG. 7 is a schematic view for explaining an example of use of the guide wire of the present invention.
[Explanation of symbols]
1 Guide wire
10 Wire body
2 First wire
21 Connection end face
3 Second wire
31 Connection end face
4 Coils
5 Coating layer
6 Second coating layer
7 Third coating layer
11, 12, 13 Fixing material
14 Welded part
15 Outer diameter gradually decreasing part
16 Outer diameter gradually decreasing part
17 Projection
18 Cross-sectional area gradually decreasing part (outer diameter gradually decreasing 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 (8)

A guide wire having a wire main body provided with a welded portion formed by joining a linear first wire disposed on a distal end side and a second wire disposed on a proximal end side of the first wire by welding. And
The second wire is provided in the vicinity of the weld, and has a first portion having a cross-sectional area smaller than a cross-sectional area of the base end portion of the first wire, and a base end side of the first portion. And a second part having a rigidity higher than that of the first part,
The first wire is made of a Ni-Ti alloy showing pseudoelasticity, and the second wire is made of a Co-Ni-Cr alloy,
A guide wire comprising a coating layer that is provided so as to cover the weld and is made of a resin material capable of reducing friction.   The Co—Ni—Cr alloy is an alloy having a composition of 28 to 50 wt% Co-10 to 30 wt% Ni-10 to 30 wt% Cr—balance Fe, or a part of each of these elements is another element (substitution The guide wire according to claim 1, which is an alloy substituted with (element). 3. The guide wire according to claim 1, wherein the first part is a cross-sectional area gradually decreasing portion in which a cross-sectional area gradually decreases toward a tip of the second wire. The guide wire according to any one of claims 1 to 3, wherein a protrusion that protrudes in an outer peripheral direction is formed on the weld. The guide wire according to claim 4, wherein the height of the protrusion satisfies a range of 0.01 to 0.3 mm. The guide wire according to claim 4 or 5, wherein the coating layer constitutes a surface of the guide wire, and the surface of the guide wire has a portion that protrudes along the curvature of the protruding portion. The guide wire according to any one of claims 1 to 6, wherein the coating layer is made of a reaction-curable silicone resin that can be formed at room temperature or a composite material containing the same. The coating layer is the guide wire according to any one of claims 1 is composed of a fluorocarbon resin 6.

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