JP5135452B2 - Guide wire - Google Patents

Description

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

  The guide wire can be used for the treatment of a site where 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.

  The blood vessel is intricately curved, and the guide wire used to insert the balloon catheter into the blood vessel has moderate flexibility and resilience to bending, and pushability to transmit the proximal end operation to the distal end. 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

  An object of the present invention is to provide a guide wire that has a moderate change in rigidity in the longitudinal direction of the wire and is excellent in operability and kink resistance.

Such an object is achieved by the present inventions (1) to (3) below.
(1) a linear first wire disposed on the distal end side;
A linear second wire that is arranged on the base end side of the first wire and is made of a material having a larger elastic modulus than the constituent material of the first wire;
The first wire and the second wire are connected by welding,
The second wire has a small cross-sectional area portion in the vicinity of a welded portion between the first wire and the second wire, whose cross-sectional area is smaller than the cross-sectional area of the base end portion of the first wire,
The small cross-sectional area portion has a first portion whose outer diameter gradually decreases in the distal direction, and a second portion that is located on the distal side from the first portion and whose outer diameter gradually increases in the distal direction. A portion, and a third portion located between the first portion and the second portion, the outer diameter of which is substantially constant along the longitudinal direction,
An outer diameter of the third portion is the smallest diameter portion in the small cross-sectional area portion.

(2) a linear first wire disposed on the distal end side;
A linear second wire that is arranged on the base end side of the first wire and is made of a material having a larger elastic modulus than the constituent material of the first wire;
The first wire and the second wire are connected by welding,
The second wire has a small cross-sectional area portion in the vicinity of a welded portion between the first wire and the second wire, whose cross-sectional area is smaller than the cross-sectional area of the base end portion of the first wire,
The small cross-sectional area portion has a first portion whose outer diameter gradually decreases in the distal direction, and a second portion that is located on the distal side from the first portion and whose outer diameter gradually increases in the distal direction. And a guide wire.

  (3) The guide wire according to (2), wherein an outer peripheral surface of a boundary portion between the first portion and the second portion forms a continuous portion without a step.

  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, by providing a small cross-sectional area on the second wire, the change in rigidity along the longitudinal direction of the portion including the welded portion is gentle, and kink (bending) and twisting in the vicinity of the welded portion are ensured. Can be prevented.

  In particular, the small cross-sectional area portion has a first portion, a second portion, and a third portion, and the outer diameter of the third portion is the smallest diameter portion of the small cross-sectional area portions. In such a case, local stress concentration on the smallest diameter portion is relaxed or distributed, and as a result, when a torsional torque or a pushing force is applied from the second wire to the first wire, Twist, kink, breakage, etc. of the smallest diameter portion can be prevented more reliably.

  The small cross-sectional area portion has a first portion and a second portion, and the outer peripheral surface of the boundary portion between the first portion and the second portion constitutes a continuous portion without a step. In such a case, local stress concentration at the boundary is prevented or alleviated, and twisting and kinking are more reliably prevented.

  Therefore, according to the present invention, a guide wire excellent in operability, kink resistance, and twist resistance can be provided.

It is a longitudinal cross-sectional view which shows the structural example of a guide wire. 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 schematic diagram for demonstrating the usage example of the guide wire of this invention. It is a schematic diagram for demonstrating the usage example of the guide wire of this invention. It is a longitudinal cross-sectional view which shows suitable embodiment of the guide wire of this invention. It is a longitudinal cross-sectional view which shows other embodiment of the guide wire of this invention. It is a longitudinal cross-sectional view which shows the other structural example of a guide wire. It is a perspective view which shows the other structural example of the small cross-sectional area part of the 2nd wire in a guide wire.

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

  FIG. 1 is a longitudinal sectional view showing a configuration example of a guide wire, and FIG. 2 is a diagram showing a procedure for connecting a first wire and a second wire in the guide wire shown in FIG. For convenience of explanation, the right side in FIG. 1 is referred to as “base end” and the left side is referred to as “tip”. Further, in FIG. 1, for the sake of easy understanding, the length direction of the guide wire is shortened and the thickness direction of the guide wire is exaggerated, and the ratio between the length direction and the thickness direction is schematically illustrated. This is very different from the actual situation (the same applies to FIGS. 5 to 7 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. It has a wire 3 and a spiral coil 4. The total length of the guide wire 1 is not particularly limited, but is preferably about 200 to 5000 mm. Further, the outer diameter of the guide wire 1 is not particularly limited, but it is usually preferably about 0.2 to 1.2 mm.

  The first wire 2 is 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 configuration shown in the drawing, the first wire 2 has an outer diameter gradually decreasing portion 22 whose outer diameter gradually decreases toward the distal end in a portion on the distal end side. Thereby, in the outer diameter gradually decreasing portion 22 of the first wire 2, the rigidity (bending rigidity, torsional rigidity) can be gradually decreased toward the distal end direction, and as a result, the guide wire 1 is excellent in the distal end portion. Flexibility is obtained, blood vessel followability and safety are improved, and bending and the like can be prevented.

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

  In the configuration shown in the drawing, the outer diameter gradually decreasing portion 22 has a tapered shape in which the outer diameter continuously decreases at a substantially constant decrease rate in the distal direction. In other words, the taper angle of the outer diameter gradually decreasing portion 22 is substantially constant along the longitudinal direction. Thereby, the change of the rigidity along the longitudinal direction of the outer diameter gradually decreasing portion 22 can be made more gradual (smooth). In addition, unlike such a configuration, the rate of decrease of the outer diameter toward the distal direction of the outer diameter gradually decreasing portion 22 (taper angle of the outer diameter gradually decreasing portion 22) may change along the longitudinal direction, For example, a portion where the reduction rate of the outer diameter is relatively large and a portion where the outer diameter is relatively small may be alternately formed a plurality of times. In this case, there may be a portion where the decrease rate of the outer diameter toward the distal end of the outer diameter gradually decreasing portion 22 becomes zero.

  The portion on the proximal end side of the first wire 2 has an outer diameter that is substantially constant along the longitudinal direction. In addition, unlike the drawing, the first wire 2 may be one in which the outer diameter gradually decreases in the distal direction over almost the entire length, that is, the first wire 2 may be one in which almost the whole is the outer diameter gradually decreasing portion 22. .

  The constituent material of the 1st wire 2 is not specifically limited, For example, although various metal materials, such as stainless steel, can be used, It is preferable that it is an alloy (a superelastic alloy is included) which shows pseudoelasticity, More preferably, it is an elastic alloy. Since the superelastic alloy is relatively flexible and has a resilience and is difficult to bend, the guide wire 1 can be sufficiently formed in the tip side portion by configuring the first wire 2 with the superelastic alloy. Flexibility and resilience to bending can be obtained, follow-up to complicatedly curved and bent blood vessels can be improved, and more excellent operability can be obtained. Even if the first wire 2 repeatedly bends and bends, Since the 1 wire 2 is not bent due to the restoring property, it is possible to prevent the operability from being deteriorated due to the bent wire being attached to the first wire 2 during use of the guide wire 1.

  Pseudoelastic alloys include those in which the stress-strain curve by tension is any shape, including those in which transformation points such as As, Af, Ms, and Mf can be measured remarkably, and those that cannot be deformed. Anything that is distorted) and returns almost to its original shape upon removal of 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.

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

  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.

  Further, the first wire and / or the second wire can be made of a so-called composite material, such as forming inner and outer layers of different materials. Even in such a case, it is preferable that the rigidity of the second wire is higher than that of the first wire.

  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, it is preferable that the first wire 2 and the second wire 3 are made of different kinds of alloys, and the first wire 2 is made of a material having a smaller elastic modulus than that of the constituent material of the second wire 3. It is preferred that 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 addition, it is preferable to use a Ni—Ti-based alloy as the superelastic alloy constituting the first wire 2 in terms 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. In the configuration shown in the figure, the coil 4 has a slight gap between the spirally wound wires in a state where no external force is applied, but unlike the illustration, the coil 4 is spiraled in a state where no external force is applied. Wires wound in a shape may be densely arranged without a gap.

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

  The proximal end portion and the distal end portion of the coil 4 are fixed to the 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 this 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.

  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 flat. 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.

  In such a guide wire 1, the second wire 3 has a small cross-sectional area portion 32 in the vicinity of the weld portion 14 whose cross-sectional area is smaller than the cross-sectional area of the base end portion 23 of the first wire 2. In other words, the second wire 3 has a cross-sectional area of a portion (small cross-sectional area portion 32) from the connection end surface 31 to a predetermined position on the base end side thereof than the cross-sectional area of the base end portion 23 of the first wire 2. It is getting smaller. In the present embodiment, since the outer diameter of the small cross-sectional area portion 32 is smaller than the outer diameter of the base end portion 23 of the first wire 2, the cross-sectional area becomes smaller than the cross-sectional area of the base end portion 23. ing. That is, the area of the connection end surface 31 is smaller than the area of the connection end surface 21.

  As described above, since the second wire 3 is made of a material having a larger elastic modulus than that of the first wire 2, the outer diameter of the distal end portion of the second wire 3 is assumed to be that of the proximal end portion 23 of the first wire 2. When it is the same as the outer diameter, the rigidity (bending rigidity, torsional rigidity) of the guide wire 1 changes rapidly across the welded portion 14. On the other hand, in the present invention, by providing the small cross-sectional area portion 32 at the distal end portion of the second wire 3 and reducing (decreasing) the rigidity (bending rigidity, torsional rigidity) in the small cross-sectional area portion 32, Changes along the longitudinal direction of the rigidity (bending rigidity, torsional rigidity) in the vicinity including the welded portion 14 can be made gentle (smooth), and the guide wire 1 can obtain excellent operability.

  In the illustrated configuration, the small cross-sectional area portion 32 has a portion where the outer diameter of the small cross-sectional area portion 32 gradually decreases toward the distal end, that is, a portion where the cross-sectional area gradually decreases toward the distal end. ing. Thereby, rigidity (bending rigidity, torsional rigidity) can be gradually decreased in the direction from the proximal end of the small cross-sectional area portion 32 to the distal end of the small cross-sectional area portion 32. As a result, the guide wire 1 is The change along the longitudinal direction of rigidity (bending rigidity, torsional rigidity) can be made more gradual (smooth).

  In the configuration shown in the figure, the small cross-sectional area portion 32 has a tapered shape in which the outer diameter (cross-sectional area) gradually decreases in the tip direction over the entire length. The portion may have a portion with a constant outer diameter (cross-sectional area), and further, there may be a portion where the outer diameter gradually increases toward the welded portion 14 on the tip side of the portion with the constant outer diameter. In these cases, the same effect as described above can be obtained. Specific examples of these configurations will be described in detail later.

  The length of the small cross-sectional area portion 32 (length indicated by L in FIG. 1) is not particularly limited, but is preferably about 3 to 1000 mm, and more preferably about 3 to 300 mm. When L is in the above range, the change in rigidity (bending rigidity, torsional rigidity) along the longitudinal direction can be made more gradual (smooth) in the vicinity including the welded portion 14.

The small cross-sectional area portion 32 is formed such that the bending rigidity at the distal end (connection end surface 31) of the second wire 3 is substantially equal to the bending rigidity at the proximal end (connection end surface 21) of the first wire 2. Is preferred. Thereby, the change of the rigidity along the longitudinal direction can be made more gradual (smooth) in the vicinity thereof including the welded portion 14. Incidentally, flexural rigidity at the tip of the second wire 3, the second moment of the connection end face 31 a (shape of the connection end faces 31, the dimensions only determined from) the I _2, the Young's modulus of the material of the second wire 3 E ₂ is obtained by E ₂ I ₂ , and the bending rigidity at the base end of the first wire 2 is I _{1 where} the cross-sectional secondary moment of the connection end surface 21 (determined only from the shape and dimensions of the connection end surface 21) is I ₁ when the Young's modulus of the first constituent material of the wire 2 and _{E 1,} obtained in the E 1 _{I 1.}

  Further, the guide wire 1 having the illustrated configuration has a step filling member 6 that fills a step formed on the outer periphery of the welded portion 14. As a result, the step on the outer periphery of the welded portion 14 formed by the outer diameter of the distal end of the second wire 3 being smaller than the outer diameter of the proximal end of the first wire 2 is eliminated. A decrease in slidability can be prevented.

  In the illustrated configuration, the step filling member 6 covers the outer periphery of the small cross-sectional area portion 32, and its outer diameter is substantially constant along the longitudinal direction and its inner diameter gradually decreases toward the distal end. The outer diameter of the guide wire 1 in the vicinity including the welded portion 14 and the small cross-sectional area portion 32 is configured to be substantially constant along the longitudinal direction. Thereby, the influence which a level | step difference has on the slidability of the guide wire 1 can be eliminated more reliably.

  The constituent material of the step filling member 6 is not particularly limited. For example, various resin materials and various metal materials can be used, but a relatively flexible material (such as a small contribution to the rigidity of the guide wire 1). For example, solder, plastic, wax, etc.) are preferable. Moreover, the form of the step filling member 6 is not limited to the illustrated configuration, and may be, for example, a coiled member.

  In the illustrated embodiment, the welded portion 14 is located closer to the proximal end than the proximal end of the coil 4, but unlike the illustration, the welded portion 14 is located closer to the distal end than the proximal end of the coil 4. May be.

  Further, when the rigidity of the first wire is weaker than the rigidity of the second wire, the sizes of the connection end faces 31 and 21 in FIG. 1 may be reversed.

  FIG. 5 is a longitudinal sectional view showing a preferred embodiment of the guide wire of the present invention. Hereinafter, the guide wire according to the present embodiment will be described with reference to this drawing. However, the difference from the above-described guide wire will be mainly described, and description of similar matters will be omitted.

  As shown in FIG. 5, the small cross-sectional area portion 32 has a first portion 32A whose outer diameter gradually decreases in the distal direction, and is positioned closer to the distal end side than the first portion 32A, and has an outer diameter in the distal direction. And a second portion 32B that gradually increases toward the end. The outer peripheral surface of the boundary portion between the first portion 32A and the second portion 32B constitutes a continuous curved surface (smooth surface) without a step. With such a configuration, stress concentration on the boundary portion is prevented or alleviated, and twisting and kink are more reliably prevented (kink resistance is improved).

  The maximum outer diameter of the second portion 32B is on the connection end surface 31 at the tip thereof, and this maximum outer diameter is substantially equal to the outer diameter of the base end (connection end surface 21) of the first wire 2. That is, in the small cross-sectional area portion 32 shown in FIG. 5, the area of the welded surface of the welded portion 14 can be made larger than in the configuration shown in FIG. 1, and the welding strength can be improved. As a result, when torsional torque or pushing force is applied from the second wire 3 to the first wire 2, damage to the welded part 14 due to stress concentration on the welded part 14 or insufficient strength can be prevented more reliably.

Further, in such a small cross sectional area 32, when the length _{L A} of the first portion 32A, the length of the second portion 32B was set to _{L B,} the _{L A} larger _{L B.} That is, the taper angle of the first portion 32A is smaller than the taper angle of the second portion 32B.

Specifically, the length _{L A} of the first portion 32A is preferably in the range of 0.1 to 1000 times the length _{L B} of the second portion 32B, is about 1.0 to 1000 times Is more preferable, and about 1.0 to 50 times is more preferable. By setting it as such conditions, the stress concentration to the welding part 14 can be suppressed and a smooth transition of rigidity can be realized.

  In the small cross-sectional area portion 32 shown in FIG. 5, the outer periphery of the small cross-sectional area portion 32 may be covered with the above-described step filling member 6, thereby obtaining the same effect as described above.

  FIG. 6 is a longitudinal sectional view showing another embodiment of the guide wire of the present invention. Hereinafter, the guide wire according to the present embodiment will be described with reference to this drawing. However, the difference from the above-described guide wire will be mainly described, and description of similar matters will be omitted.

  As shown in FIG. 6, the small cross-sectional area portion 32 included in the guide wire 1 ″ of the present embodiment has a third outer diameter that is substantially constant between the first portion 32A and the second portion 32B. Other than that, the configuration is the same as that shown in Fig. 5. The outer diameter of the third portion 32C is the smallest diameter portion of the small cross-sectional area portion 32.

The small cross-sectional area portion 32 shown in FIG. 6 also has the same operation and effect as the small cross-sectional area portion 32 shown in FIG. 5, but in particular, by providing the third portion 32C, the small cross-sectional area portion 32 is provided. Since the minimum diameter portion in the inside continuously exists for a certain length (L _C below), the stress concentration on the minimum diameter portion in the small cross-sectional area portion 32 is reduced as compared with the configuration shown in FIG. As a result, when twisting torque or pushing force is applied from the second wire 3 to the first wire 2, twisting, kinking, breakage, etc. of the smallest diameter portion in the small cross-sectional area portion 32 can be prevented more reliably. can do.

  The third portion 32C preferably has substantially the same rigidity as the vicinity of the proximal end portion 23 of the first wire 2. Further, the outer diameter of the third portion 32C is such an outer diameter that has substantially the same rigidity as that of the vicinity of the proximal end portion 23 of the first wire 2, and therefore, the proximal end portion of the first wire 2 from the small cross-sectional area portion 32. A smooth transition of rigidity to 23 is realized.

  The outer peripheral surface of the boundary portion between the first portion 32A and the third portion 32C and the outer peripheral surface of the boundary portion between the third portion 32C and the second portion 32B are respectively continuous curved surfaces having no steps (slowly The other side). Thereby, the same effect as described above can be obtained.

_A preferable relationship between the length L _A of the first portion 32A and the length L _B of the second portion 32B is the same as described above. The relationship between the length _{L C} of the third portion 32C is not particularly limited, preferably in the _{L B} ≦ _{L C} ≦ _{L A} or _{L B ≦ L A ≦ L C} .

Further, in the present embodiment, the length _{L A} of the first portion 32A is preferably in the range of about 0.1 to 1000 times the length _{L B} of the second portion 32B, 0.1 to 10 times It is more preferable that By setting it as such conditions, the stress concentration to the welding part 14 can be suppressed and a smooth transition of rigidity can be realized.

Further, while maintaining the strength of the small cross sectional area 32, in order to obtain relief or dispersion effect of stress concentration to the minimum diameter portion sufficiently long L _C of the third portion 32C is, 0.1～200Mm Is preferably about 1 to 50 mm.

  In the small cross-sectional area portion 32 shown in FIG. 6, the outer periphery of the small cross-sectional area portion 32 may be covered with the above-described step filling member 6, thereby obtaining the same effect as described above.

  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 <3> 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 deleted. Next, the base end side portion of the welded portion 14 of the second wire 3, that is, the distal end portion of the second wire 3 is polished, for example, a small cross-sectional area having a desired shape as shown in FIG. 1, FIG. 5 or FIG. A portion 32, that is, a small cross-sectional area portion 32 whose outer diameter gradually decreases toward the distal end or has such a portion is formed.

  The first wire 3 having a small cross-sectional area 32 having a desired shape (the outer diameter gradually decreases or has such a portion) is obtained by polishing the tip of the second wire 3 in advance. The wire 2 may be welded in pressure contact.

  FIG. 3 and FIG. 4 are views showing a use state when the guide wire 1 ″ of the present invention is used for PTCA.

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

  As shown in FIG. 3, the distal end of the guide wire 1 "protrudes from the distal end of the guiding catheter 30 and is inserted into the right coronary artery 50 from the right coronary artery opening 60. Further, the guide wire 1" is advanced to advance the distal end. Is inserted into the right coronary artery and stopped at a position where the tip 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. 4, 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 form a right coronal shape. It is inserted into the right coronary artery 50 from the arterial opening 60 and stops when the balloon reaches the position of the vascular stenosis 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.

  FIG. 7 is a longitudinal sectional view showing another configuration example of the guide wire. Hereinafter, the guide wire of the present configuration example will be described with reference to this drawing. However, the description will focus on differences from the above-described embodiment and the like, and description of similar matters will be omitted.

  In the guide wire 1 ′ of the present configuration example, the first wire 2 has an outer diameter gradually decreasing portion 22 and an outer diameter gradually decreasing portion 24 provided on the proximal side from the outer diameter gradually decreasing portion 22. Thus, the first wire 2 may have outer diameter gradually decreasing portions at a plurality of portions.

  Further, in the present configuration example, the protruding portion 15 protruding in the outer peripheral direction is formed on the welded portion 14. By forming such a protrusion 15, 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 15, for example, the welded portion 14 between the first wire 2 and the second wire 3 can be more easily viewed under X-ray fluoroscopy. As a result, by confirming the X-ray fluoroscopic image, it is possible to easily and reliably grasp the progress of the guide wire 1 ′ and the catheter in the blood vessel, etc., and contribute to shortening the operation time and improving safety. Can do.

  Further, as described above, the first wire 2 and the second wire 3 are usually made of materials having different elastic moduli. For this reason, by providing the projecting portion 15, the operator can easily and reliably recognize a site where the elastic modulus of the guide wire 1 ′ changes relatively greatly. As a result, the guide wire 1 ′ is excellent in operability, and can contribute to shortening the treatment time and improving safety.

  The height of the protrusion 15 is not particularly limited because it depends on the outer diameter of the first wire 2 or the second wire 3, but is preferably 0.001 to 0.3 mm, and is 0.005 to 0.05 mm. Is more preferable. If the height of the projecting portion 15 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 15 exceeds the upper limit, 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 15. 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.

  In the configuration shown in FIG. 7, the projecting portion 15 has a substantially arc shape on one side (upper side in FIG. 7) and the opposite side (lower side in FIG. 7) in the longitudinal section thereof. The welded portion 14 is located at the maximum outer diameter portion. 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, in the present invention, it goes without saying that the shape of the protrusion 15 and the position of the welded portion 14 with respect to the protrusion 15 are not limited thereto. For example, the projecting portion 15 may have a non-circular (non-arc-shaped) shape such as a trapezoid or a triangle, for example, on the one side and the opposite side in the longitudinal section. Further, the protruding portion 15 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 welding portion 14. Moreover, the protrusion 15 has a base end side (second wire 3 side) or a tip end side (first wire 3) instead of the central portion as shown in FIG. It may be located at a position biased toward the 1 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.

  Further, the guide wire 1 ′ of this configuration example has a coating layer 7 on the outer surface (outer peripheral surface) side thereof. As described above, the guide wire 1 ′, 1 ″ and the guide wire 1 shown in FIG. 1 may have a coating layer that covers all or a part of the outer surface (outer peripheral surface). The layer 7 can be formed for various purposes. As one example, the operability of the guide wire 1 ′ is improved by reducing the friction (sliding friction) of the guide wire 1 ′ and improving the slidability. There are things to do.

  For this purpose, the coating layer 7 is preferably made of a material that can reduce friction. As a result, 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 ′ within the catheter is improved. Become. 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. Kink and twist can be prevented more reliably.

  Examples of materials that can reduce such friction include polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polyesters (PET, PBT, etc.), polyamides, polyimides, polyurethanes, polystyrenes, polycarbonates, silicone resins, fluorine resins ( PTFE, ETFE, etc.), silicone rubber, other various elastomers (for example, polyamide elastomers, polyester elastomers, etc.) or composite materials thereof, among which fluorine resins (or including them) are particularly mentioned. Composite material) is preferred, and PTFE is more preferred.

  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.

  Moreover, by providing such a coating layer 7, the step filling member 6 described above can be omitted or simplified. That is, since the covering layer 7 is formed so as to cover the step near the welded portion 14, even when the step filling member 6 is omitted or simplified, the slidability of the guide wire 1 ′ by the step. Can be sufficiently prevented.

  Such a coating layer 7 may be formed on the entire length of the guide wire 1 ′ or a part in the longitudinal direction, but covers the welded portion 14 and the small cross-sectional area portion 32, that is, the welded portion 14 and the small cross-sectional area. It is preferably formed at a location including the portion 32.

  The covering layer 7 is formed so that the outer diameter of the guide wire 1 ′ in the vicinity of the portion including the welded portion 14 and the small cross-sectional area portion 32 is substantially constant along the longitudinal direction. That is, the coating layer 7 covers the small cross-sectional area portion 32 and the protrusion 15 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.

  The thickness of the 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. If the thickness of the coating layer 7 is too thin, the purpose of forming the coating layer 7 may not be sufficiently exhibited, the peeling of the coating layer 7 may occur, and the thickness of the coating layer 7 is too thick. Then, the physical properties of the wire may be hindered, and the coating layer 7 may be peeled off.

  In the present invention, treatment (chemical treatment, heat treatment, etc.) for improving the adhesion of the coating layer 7 to the outer peripheral surface (surface) of the guide wire body (first wire 2, second wire 3, coil 4, etc.). ) Or an intermediate layer that can improve the adhesion of the coating layer 7.

  Moreover, the coating layer 7 may have a substantially constant composition in each part, or may have a different composition. For example, the constituent material of the coating layer 7 may be different between at least a region (first coating layer) covering the coil 4 and a region (second coating layer) closer to the base end than the region. Further, as shown in the figure, the first coating layer and the second coating layer may be formed in a continuous manner in the longitudinal direction, but the base end of the first coating layer and the second coating layer The tip may be separated, or the first coating layer and the second coating layer may partially overlap.

  FIG. 8 is a perspective view showing another configuration example of the small cross-sectional area portion of the second wire in the guide wire.

  The small cross-sectional area portion 32 of the second wire 3 shown in FIG. 8A is not reduced in outer diameter, and the outer diameter is the same as the proximal end portion of the small cross-sectional area portion 32. . The small cross-sectional area portion 32 has a hollow portion 321, and the inner diameter of the hollow portion 321 gradually increases in the distal direction. That is, the hollow portion 321 has a shape like a cone (or a truncated cone). By forming such a hollow portion 321, the small cross-sectional area portion 32 has a cross-sectional area smaller than the base end portion 23 of the first wire 2 and the cross-sectional area gradually decreases toward the distal end direction, The rigidity (bending rigidity, torsional rigidity) is also gradually reduced toward the tip. In the present invention, even when the small cross-sectional area portion 32 has the form shown in FIG. 8A, the same effect as that of the above-described embodiment can be obtained. Further, by forming the hollow portion 321 and reducing the transverse area without changing the outer diameter, there is a step in the welded portion 14 with the base end portion 23 of the first wire 2 without providing the step filling member 6. There is also an advantage that it does not occur. The hollow portion 321 may have a shape like a pyramid (or a truncated pyramid). Further, in this case, the rigidity before and after the welded portion 14 changes more smoothly by welding so that a part of the base end portion 23 of the first wire 2 is inserted into the hollow portion 321 of the second wire 3. Therefore, kink resistance is further improved.

  The small cross-sectional area portion 32 of the second wire 3 shown in FIG. 8B has a shape like a truncated pyramid (hexagonal pyramid), and the size of the polygon (regular hexagon) in the cross section is small. By gradually decreasing toward the distal end direction, the cross-sectional area gradually decreases toward the distal end direction, and its rigidity (bending rigidity, torsional rigidity) also decreases gradually toward the distal end direction. Even in the case where the small cross-sectional area portion 32 has the form shown in FIG. 8B, the same effect as that of the above-described embodiment can be obtained.

  As mentioned above, although the guide wire of this invention was demonstrated about embodiment of illustration, this invention is not limited to this, Each part which comprises a guide wire is a thing of arbitrary structures which can exhibit the same function. Can be substituted. Moreover, arbitrary components may be added.

1, 1 ′, 1 ″ Guide wire 2 First wire 21 Connection end surface 22 Outer diameter gradually decreasing portion 23 Base end portion 24 Outer diameter gradually decreasing portion 3 Second wire 31 Connection end surface 32 Small cross-sectional area portion 32A First portion 32B Second Part 32C Third part 321 Hollow part 4 Coil 6 Step filling member 7 Cover layer 11, 12, 13 Fixing material 14 Welding part 15 Protrusion 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 (3)

A linear first wire disposed on the distal end side;
A linear second wire that is arranged on the base end side of the first wire and is made of a material having a larger elastic modulus than the constituent material of the first wire;
The first wire and the second wire are connected by welding,
The second wire has a small cross-sectional area portion in the vicinity of a welded portion between the first wire and the second wire, whose cross-sectional area is smaller than the cross-sectional area of the base end portion of the first wire,
The small cross-sectional area portion has a first portion whose outer diameter gradually decreases in the distal direction, and a second portion that is located on the distal side from the first portion and whose outer diameter gradually increases in the distal direction. A portion, and a third portion located between the first portion and the second portion, the outer diameter of which is substantially constant along the longitudinal direction,
An outer diameter of the third portion is the smallest diameter portion in the small cross-sectional area portion. A linear first wire disposed on the distal end side;
A linear second wire that is arranged on the base end side of the first wire and is made of a material having a larger elastic modulus than the constituent material of the first wire;
The first wire and the second wire are connected by welding,
The second wire has a small cross-sectional area portion in the vicinity of a welded portion between the first wire and the second wire, whose cross-sectional area is smaller than the cross-sectional area of the base end portion of the first wire,
The small cross-sectional area portion has a first portion whose outer diameter gradually decreases in the distal direction, and a second portion that is located on the distal side from the first portion and whose outer diameter gradually increases in the distal direction. And a guide wire.   The guide wire according to claim 2, wherein an outer peripheral surface of a boundary portion between the first portion and the second portion constitutes a continuous portion without a step.

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