JP5605949B2 - Medical guidewire - Google Patents

Description

  The present invention relates to a medical guide wire in which a coil spring is attached to the outer periphery of a small diameter portion on the distal end side of a core wire.

A guide wire for guiding a medical device such as a catheter to a predetermined position in a body cavity such as a blood vessel is required to have flexibility at the distal end.
For this reason, the outer diameter of the distal end portion of the core wire is made smaller than the outer diameter of the proximal end portion, and a coil spring is attached to the outer periphery of the distal end portion (distal end side small diameter portion) of the core wire. A guide wire intended to improve the flexibility of the distal end is known (see, for example, Patent Document 1).

  In order to attach the coil spring to the outer periphery of the small-diameter portion on the distal end side of the core wire, each of the front end portion and the rear end portion of the coil spring is usually fixed to the core wire with solder.

Recently, it has been desired to reduce the size of medical devices in order to achieve minimal invasiveness to patients.
Along with this, there has been a demand for a thinner guide wire, and the present inventors have developed a guide wire having an outer diameter (0.010 inch) thinner than the conventional one (outer diameter is 0.014 inch). ing.

The 0.010 inch guide wire can greatly contribute to miniaturization of medical devices such as catheters.
Further, according to this guide wire, for example, the operability when accessing the microchannel in a CTO (chronic total occlusion) lesion is also good to some extent.

  However, a thin guide wire has low bending rigidity (kink resistance) and inferior pushability (pushability).

  Under such circumstances, the present inventor is a guide wire in which a coil spring is mounted on the outer periphery of the small diameter portion of the distal end side of the core wire, and the coil outer diameter on the tip side of the coil spring is 0.010 inch. Therefore, a guide wire in which the outer diameter of the coil on the rear end side of the coil spring and the outer diameter of the proximal end of the core wire are both 0.014 inches has been developed and proposed (see Patent Document 2). .

JP 2003-299739 A Japanese Patent No. 4354525

Some microchannels in CTO lesions have a pore size smaller than 0.010 inches, and a further reduction in the diameter of the guide wire (coil outer diameter of the coil spring) is required in order to pass through such a microchannel. It becomes.
On the other hand, if the coil outer diameter of the coil spring that constitutes the guide wire is different between the front end side and the rear end side, stress is concentrated on the part where the coil diameter changes when the constricted part such as a microchannel is inserted. Then, there is a problem that it becomes easy to kink in that portion. Further, a guide wire having a coil spring whose coil outer diameter largely changes does not have a good pushability.

Further, the guide wire is required to have a good torque transmission property (the rotational torque on the proximal end side is well transmitted to the distal end side). If the torque transmission is not sufficient, it is difficult to advance to the target blood vessel by selecting the blood vessel branch, and the insertion workability is impaired.
However, a guide wire having a small diameter or a guide wire having a coil spring whose coil outer diameter largely changes tends to be inferior in torque transmission.

  Further, the guide wire is required to be less likely to cause permanent deformation (shape retention) even when bent through a tortuous blood vessel. If permanent deformation occurs during the procedure, subsequent operations in the blood vessel may be difficult, such as undulation due to rotation by hand operation.

The present invention has been made based on the above situation.
The first object of the present invention is that it can be inserted into a narrowed portion having a small hole diameter that could not be inserted with a conventional guide wire, has high bending rigidity (kink resistance), and excellent pushability. It is to provide a medical guide wire.
A second object of the present invention is to provide a medical guide wire having excellent shape retaining property, which has good torque transmission property, and hardly causes permanent deformation even when passing through a tortuous blood vessel. .

(1) The medical guide wire of the present invention is made of austenitic stainless steel having a tensile strength of 2600 to 3000 MPa, and has a proximal end side large diameter portion and a distal end having a smaller outer diameter than the proximal end side large diameter portion. A core wire having an end-side small diameter portion;
A coil spring that is mounted along the axial direction on the outer periphery of the small-diameter portion on the distal end side of the core wire, and that is fixed to the core wire at least at the front end portion and the rear end portion;
The coil spring is
A tip-side small diameter portion having a coil outer diameter of 0.008 inch ( 0.203 mm ) or less;
A medium diameter portion having a coil outer diameter larger than the coil outer diameter of the tip side small diameter portion;
A rear end side large-diameter portion having a coil outer diameter of 0.012 inch (0.305 mm) or more and larger than the coil outer diameter of the medium-diameter portion;
A first taper portion located between the tip side small diameter portion and the medium diameter portion;
A second taper portion located between the medium diameter portion and the rear end side large diameter portion;
When a 150 gf tensile load is applied for 10 seconds with the small diameter portion of the core wire to which the coil spring is fixed wound once along the outer periphery of a rod having a diameter of 3 mm, the tip portion of the core wire is wound. The warping angle is less than 25 °.

(2) In the medical guide wire of the present invention, the proximal end side large-diameter portion made of austenitic stainless steel having a tensile strength of 2600 to 3000 MPa and having an outer diameter of 0.012 inch (0.305 mm) or more. And a core wire having a distal end side small diameter portion having a smaller outer diameter than the proximal end side large diameter portion;
Attached along the outer circumference of the small-diameter portion on the distal end side of the core wire along the axial direction, a closely wound portion having a coil pitch 1.1 to 2.0 times the coil wire diameter, and continuous to the closely wound portion, A coil spring comprising a coarsely wound portion having a coil pitch exceeding 2.0 times the coil wire diameter;
The coil spring is
A tip-side small diameter portion having a coil outer diameter of 0.008 inch ( 0.203 mm ) or less;
A medium diameter portion having a coil outer diameter larger than the coil outer diameter of the tip side small diameter portion;
A rear end side large-diameter portion having a coil outer diameter of 0.012 inch (0.305 mm) or more and larger than the coil outer diameter of the medium-diameter portion;
A first taper portion located between the tip side small diameter portion and the medium diameter portion;
A second taper portion located between the medium diameter portion and the rear end side large diameter portion;
The tightly wound portion having a length of 5.5 to 110 mm is constituted by the distal end side small diameter portion, the first taper portion, the medium diameter portion, and the second taper portion, and the rear end side large diameter. The sparsely wound portion is constituted by a portion;
The distal end portion of the distal end side small diameter portion, the rear end portion of the second tapered portion, and the rear end portion of the rear end side large diameter portion are fixed to the outer periphery of the distal end side small diameter portion of the core wire by solder,
When a 150 gf tensile load is applied for 10 seconds with the small diameter portion of the core wire to which the coil spring is fixed wound once along the outer periphery of a rod having a diameter of 3 mm, the tip portion of the core wire is wound. The warp angle (hereinafter also referred to as “bending heel angle (θ)”) is preferably less than 25 °.

  According to such a medical guide wire, the coil spring constituting the medical guide wire has a distal end side small diameter portion having a coil outer diameter of 0.008 inches or less, and thus cannot be inserted through a conventional guide wire. It can be inserted into a stenotic region having a small pore diameter, and a narrow region (for example, a microchannel having a pore diameter of 250 μm or less in a CTO lesion) that cannot be performed using a conventional guide wire can be treated.

  In addition, this coil spring has a rear end side large diameter portion with a coil outer diameter of 0.012 inches or more, and the tip end small diameter portion, the medium diameter portion, the rear end side large diameter portion, and the coil outer diameter in stages. Since it has changed, the guide wire provided with this coil spring has high bending rigidity and excellent pushability.

  In addition, the distal end portion of the distal end side small diameter portion, the rear end portion of the second taper portion, and the rear end portion of the rear end side large diameter portion are fixed to the outer periphery of the distal end side small diameter portion of the core wire by solder. Thus, the coil spring can be securely fixed to the distal end side small diameter portion of the core wire, and the distal end side small diameter portion (excluding the distal end portion), the first tapered portion, the intermediate diameter portion, and the second tapered portion. Since the portions (excluding the rear end portion) are not fixed to the outer periphery of the small-diameter portion on the distal end side of the core wire by solder, it is possible to sufficiently ensure flexibility in the closely wound portion that is the tip region of the coil spring. In addition, it is possible to perform shaping in the region.

  In addition, since the closely wound portion of the coil spring is constituted by the distal end side small diameter portion, the first tapered portion, the medium diameter portion, and the second tapered portion, good contrast is achieved in the closely wound portion that is the distal end region of the coil spring. (Visibility) can be expressed.

  In addition, since the resistance when inserting the coil spring into the constricted part varies depending on the outer diameter of the coil, the insertion length of the coil spring into the constricted part changes the insertion resistance with the stepwise change of the outer diameter of the coil (feel). ).

  In addition, the core wire is made of high strength austenitic stainless steel having a tensile strength of 2600 to 3000 MPa, and the bending wrinkle angle (θ) as a guide wire is less than 25 °. Is excellent in shape retention (for example, shaping shape retention), having good torque transmission, hardly causing permanent deformation even when passing through a tortuous blood vessel.

(3) In the medical guidewire of the present invention, the outer diameter of the proximal end side large diameter portion of the core wire is 0.014 inch (0.356 mm) or more, and the coil of the distal end side small diameter portion of the coil spring An outer diameter of 0.008 inch ( 0.203 mm ) or less, a coil outer diameter of the medium diameter portion of 0.009 to 0.011 inch (0.229 to 0.279 mm ) , and a coil of the rear end side large diameter portion The outer diameter is preferably 0.014 inch (0.356 mm) or more.

(4) Further, in this medical guide wire, the ratio of the coil outer diameter of the distal end side small diameter portion to the coil outer diameter of the medium diameter portion is 0.5 to 0.9, and the length of the first taper portion Is 0.5 to 10 mm, the ratio of the coil outer diameter of the rear end side large diameter portion to the coil outer diameter of the medium diameter portion is 1.1 to 2.3, and the length of the second tapered portion is 0. It is preferable that it is 5-10 mm.

(5) In the medical guide wire of the present invention, the distal end portion of the distal-side small-diameter portion is fixed to the core wire with gold-containing solder, and the length of the distal-end rigid portion with the gold-containing solder is 0.1 to 0. 0.5 mm is preferable.

  Here, “gold-containing solder” includes Au alloy solder such as Au—Sn solder, Au—Ge solder, Au—Si solder, Au—In solder, Au—Sb solder, and Au solder. It is.

Moreover, the “tip rigid portion” means a tip portion of a coil spring (guide wire) that can no longer be bent freely due to solder penetrating the inside of the coil. When the tip is formed by solder, The tip is also part of the tip rigid portion.
Further, the “length of the tip rigid portion” refers to the length of the guide wire in the axial direction from the tip of the guide wire to the rear end of the solder that has penetrated into the coil.

By using gold-containing solder as the solder for fixing the tip portion of the tip side small diameter portion (tip portion of the coil spring) to the core wire, the length of the tip rigid portion is as short as 0.1 to 0.5 mm (solder Despite being narrow), the strength of the coil spring to the core wire can be sufficiently high (higher than the breaking strength of the small diameter portion at the distal end of the core wire) and inserted into the coil spring. Even if a tensile force is applied to the core wire in a state of being, the core wire is not pulled out.
And since the length of the tip rigid portion is as short as 0.1 to 0.5 mm, the shaping length (bending length of the tip) can be shortened (0.7 mm or less). As a result, the microchannel The frictional resistance can be sufficiently reduced during the operation.

(6) Moreover, in this medical guide wire, it is preferable that the gold-containing solder permeates into the inside of the coil in a range corresponding to 1 to 4 pitches from the tip in the small diameter portion on the tip side of the coil spring.
Here, for example, the penetration into the coil within a range corresponding to 3 pitches from the tip means that the rear end of the solder that has penetrated into the coil contacts the third coil from the tip, and the fourth winding The case where the coil is not in contact with the coil.

(7) In the medical guide wire of the present invention, the coil spring is filled with resin, and a resin layer is formed on the outer periphery of the coil spring, and the surface of the resin layer is hydrophilic. It is preferable that a resin layer is laminated and a water-repellent resin layer is formed on the surface of the core wire.

  By filling the inside of the coil spring with resin, the integrity of the core wire and the coil spring can be remarkably improved, thereby further improving the torque transmission and operability of the guide wire.

  Further, since the hydrophilic resin layer is laminated on the outer periphery of the coil spring through the resin layer made of the same resin as that filled in the coil spring, the hydrophilic resin layer is securely fixed and hydrophilic. The lubricity due to the functional resin can be stably expressed.

  In addition, since the water-repellent resin layer is formed on the surface of the core wire, it is possible to prevent the patient's blood from coming into contact with the metal constituting the core wire and causing allergies. Thus, adhesion of blood and the like can be reliably prevented. Moreover, the lubricity with respect to another medical device can be expressed.

According to the medical guide wire of the present invention, it can be inserted into a stenotic region having a small hole diameter that could not be inserted with a conventional guide wire.
The medical guidewire of the present invention has high bending rigidity (kink resistance) and excellent pushability.
The medical guide wire of the present invention has a good torque transmission property and is easy to be advanced to a target blood vessel by selecting a blood vessel branch, and is excellent in insertion workability.
The medical guide wire of the present invention is less likely to be permanently deformed even when bent, and has excellent shape retention.

It is the side view which fractured | ruptured a part which shows 1st Embodiment of the guide wire of this invention. It is the side view (figure for demonstrating a dimension) which fractured | ruptured a part which shows 1st Embodiment of the guide wire of this invention. FIG. 2 is a partially enlarged view of FIG. 1, (A) is a detailed view of part A, (B) is a detailed view of part B, (C) is a detailed view of part C, and (D) is a detailed view of part D. It is a side view which shows the state which shaped the front-end | tip part of the guide wire. It is explanatory drawing of the measuring method of the bending habit angle ((theta)) of a guide wire. It is a partially broken side view which shows 2nd Embodiment of the guide wire of this invention. It is a partially broken side view (figure for demonstrating a dimension) which shows 2nd Embodiment of the guide wire of this invention. FIG. 7 is a partially enlarged view of FIG. 6, where (A) is a detailed view of part A, (B) is a detailed view of part B, and (C) is a detailed view of part C. It is a partially broken side view which shows 3rd Embodiment of the guide wire of this invention. It is a partially broken side view (figure for demonstrating a dimension) which shows 3rd Embodiment of the guide wire of this invention. It is the elements on larger scale of Drawing 9, (A) is the A section detailed drawing, (B) is the B section detailed drawing, (C) is the C section detailed drawing. It is explanatory drawing which shows the simulation apparatus for testing the torque transmission property of a guide wire. It is a graph which shows the torque transmissibility of a guide wire.

<First Embodiment>
The medical guide wire of the present embodiment shown in FIGS. 1 to 3 is made of austenitic stainless steel having a tensile strength of 2600 to 3000 MPa, and has a large diameter portion 13 on the proximal end side having an outer diameter of 0.012 inches or more. And a distal end side small diameter portion 11 having an outer diameter smaller than that of the proximal end side large diameter portion 13, and a tapered portion 12 positioned between the proximal end side large diameter portion 13 and the distal end side small diameter portion 11. A core wire 10 having a tightly wound portion 201 which is attached to the outer periphery of the small diameter portion 11 on the distal end side of the core wire 10 along the axial direction and has a coil pitch 1.1 to 2.0 times the coil wire diameter; A coil spring 20 that is continuous with the winding portion 201 and comprises a coarse winding portion 202 having a coil pitch exceeding 2.0 times the coil wire diameter; the coil spring 20 is outside the coil of 0.008 inch or less. Tip with diameter (D ₂₁ ) An end-side small-diameter portion 21, a medium-diameter portion 23 having a coil outer diameter (D ₂₃ ) larger than the coil-outer diameter (D ₂₁ ) of the tip-side small-diameter portion 21; A rear end side large diameter portion 25 having a coil outer diameter (D ₂₅ ) larger than the coil outer diameter (D ₂₃ ), a first taper portion 22 positioned between the front end side small diameter portion 21 and the medium diameter portion 23; The second tapered portion 24 is located between the middle diameter portion 23 and the rear end side large diameter portion 25, and the distal end side small diameter portion 21, the first tapered portion 22, the middle diameter portion 23, and the second tapered portion 24. And a densely wound portion 201 having a length (L ₂₁ + L ₂₂ + L ₂₃ + L ₂₄ ) of 5.5 to 110 mm is formed, and a loosely wound portion 202 is formed by the rear end side large diameter portion 25; The front end portion of the side small diameter portion 21, the rear end portion of the second taper portion 24, and the rear end portion of the rear end side large diameter portion 25 are The core wire 10 is fixed to the outer periphery of the distal end side small-diameter portion 11 of the core wire 10 by the Au-Sn solder 31, the Au-Sn solder 32, and the Ag-Sn solder 33, and the coil spring 20 is fixed. When the 150 gf tensile load is applied for 10 seconds with the distal end side small diameter portion 11 wound once along the outer periphery of the rod having a diameter of 3 mm, the warping angle of the tip portion due to winding (the bending curve which is permanent deformation) A medical guide wire having an angle (θ) of less than 25 °.

The guide wire of this embodiment includes a core wire 10 and a coil spring 20.
The core wire 10 includes a distal end side small diameter portion 11 that is tapered so as to expand in the proximal direction, a tapered portion 12 that expands in the proximal direction, and a proximal end large diameter portion 13.
The distal end side small diameter portion 11, the taper portion 12, and the proximal end side large diameter portion 13 are integrally configured by the same wire (for example, a round bar member).

The cross section of the taper part 12 and the proximal end side large diameter part 13 is substantially circular.
The cross section on the proximal end side of the distal end side small diameter portion 11 is substantially circular, but the distal end side of the distal end side small diameter portion 11 may be formed into a plate shape by compressing the wire. In that case, the cross section is substantially rectangular.

The core wire 10 is made of high strength austenitic stainless steel (for example, SUS304, SUS316) having a tensile strength of 2600 to 3000 MPa.
A high-strength austenitic stainless steel having a tensile strength of 2600 to 3000 MPa also has a high elastic limit. Therefore, in the guide wire of this embodiment using this as a core wire, it is difficult to cause permanent deformation due to bending.

The core wire 10 is a wire rod having a predetermined wire diameter and strength by drawing a wire of austenitic stainless steel, then straightening, and then cutting to a predetermined length to obtain a bar material. Next, it can manufacture by performing an aging process on the processing conditions of temperature 300-500 degreeC and time 0.5-4 hours.
Here, the “aging treatment” is performed for the purpose of removing (reducing) the residual stress in the portion that becomes the distal end side small diameter portion 11 and preventing the undulation on the distal end side.
When the aging treatment temperature is less than 300 ° C. or more than 500 ° C., it is possible to obtain a core wire 10 having a tensile strength of 2600 MPa or more and to obtain a guide wire having a bending angle (θ) of less than 25 °. It becomes difficult.
Moreover, if the aging treatment time is less than 0.5 hours, the residual stress cannot be sufficiently removed. On the other hand, even if the treatment is performed for more than 4 hours, an effect corresponding to the time cannot be obtained.

A water repellent resin layer (not shown) is formed on the outer peripheral surface of the core wire 10.
As the resin constituting the water-repellent resin layer, any resin that is used for medical purposes and has water repellency can be used, and suitable resins include fluorine-based resins such as PTFE.

The total length (L ₁ ) of the guide wire shown in FIG. 2 is, for example, 1500 to 3000 mm, and is 1780 mm if a suitable example is shown.
The outer diameter (D ₁ ) of the proximal end side large-diameter portion 13 of the core wire 10 is 0.012 inch (0.305 mm) or more, preferably 0.014 inch (0.356 mm) or more. One example is 0.014 inch.

The maximum outer diameter of the distal end side small-diameter portion 11, is not particularly limited smaller than the inner diameter of the coil spring 20, the outer diameter of the proximal end side large-diameter portion 13 (D ₁₎ 1/5 It is preferably about ˜3 / 5.
The distal end side small diameter portion 11 may be continuously reduced in diameter toward the tip end side, or may be reduced in steps.

  The coil spring 20 constituting the guide wire is composed of one wire, and is attached to the outer periphery of the distal end side small diameter portion 11 of the core wire 10 along the axial direction.

Although the outer diameter (coil wire diameter) of the wire which comprises the coil spring 20 is not specifically limited, Preferably it is 30-90 micrometers, and if it shows a suitable example, it will be 50 micrometers.
The material of the coil spring 20 is a material (X-ray opaque material) having good contrast with respect to X-rays, such as platinum, platinum alloy (for example, Pt / W = 92/8), gold, gold-copper alloy, tungsten, and tantalum. ).

  The coil spring 20 includes a front end side small diameter portion 21, a first taper portion 22, a medium diameter portion 23, a second taper portion 24, and a rear end side large diameter portion 25.

The distal end side small diameter portion 21, the first taper portion 22, the medium diameter portion 23, and the second taper portion 24 constitute a closely wound portion 201 of the coil spring 20. The closely wound portion 201 (the distal end side small diameter portion 21, the first tapered portion 22, the intermediate diameter portion 23, and the second tapered portion 24) of the coil spring 20 and the distal end tip described later serve as an X-ray opaque region.
The rear end side large diameter portion 25 constitutes a loosely wound portion 202 of the coil spring 20.

The coil pitch in the closely wound portion 201 on the front end side is 1.1 to 2.0 times the coil wire diameter, and 1.5 times if a suitable example is shown.
When the coil pitch is less than 1.1 times the coil wire diameter, the flexibility of the region is impaired. On the other hand, when the coil pitch exceeds 2.0 times the coil wire diameter, good contrast cannot be expressed in the region.
The coil pitch in the sparsely wound portion 202 on the rear end side exceeds 2.0 times the coil wire diameter, and is 3.0 times if a suitable example is shown.
As described above, by changing the coil pitch between the front end side and the rear end side, good contrast (visibility) can be exhibited in the closely wound portion 201 which is the front end region.
When the same pitch is used over the entire coil spring, the X-ray opaque region becomes longer, resulting in a decrease in visibility.

In FIG. 2, the length (L ₂ ) of the coil spring 20 is, for example, 30 to 800 mm, preferably 100 to 200 mm, and 165 mm if a suitable example is shown.
The length (L ₂₁ ) of the distal end side small diameter portion 21 is 0.5 to 100 mm, preferably 3 to 15 mm, and 8.5 mm if a suitable example is shown.
The length of the first taper portion 22 (L ₂₂₎ is preferably 0.5 to 10 mm, a 1.5mm as a preferable example.
The length (L ₂₃ ) of the medium diameter portion 23 is 0.5 to 150 mm, preferably 10 to 50 mm, and 28.5 mm if a suitable example is shown.
The length (L ₂₄ ) of the second taper portion 24 is preferably 0.5 to 10 mm, and is 1.5 mm if a suitable example is shown.
The length (L ₂₅ ) of the rear end side large diameter portion 25 is, for example, 85 to 154.5 mm, and is 125 mm if a suitable example is shown.

The length of the closely wound portion 201 of the coil spring 20, that is, the length (L ₂₁ + L ₂₂ + L ₂₃ + L ₂₄ ) from the front end of the front end side small diameter portion 21 to the rear end of the second taper portion 24 is usually 5.5. ˜110 mm, preferably 10.5 to 80 mm, and 40.0 mm (8.5 mm + 1.5 mm + 28.5 mm + 1.5 mm) as a suitable example.
When this length (L ₂₁ + L ₂₂ + L ₂₃ + L ₂₄ ) is 5.5 mm or more, for most microchannels, the density from the front end of the small-diameter portion 21 on the tip side to the rear end of the second taper portion 24 is increased. The winding part 201 can be inserted (penetrated).
In addition, since the length (L ₂₁ + L ₂₂ + L ₂₃ + L ₂₄ ) is 110 mm or less, the length (L ₂₅ ) of the rear end side large-diameter portion 25 that contributes to the improvement of bending rigidity and pushability is sufficiently obtained. Can be secured.

The length (L ₃ + L ₂ ) from the front end of the guide wire to the rear end of the coil spring 20 is, for example, 30 to 800 mm, and is 165.2 mm (0.2 mm + 165 mm) as a suitable example.
The length (L ₃ + L ₂₁ + L ₂₂ + L ₂₃ + L ₂₄ ) from the front end of the guide wire to the rear end of the second taper portion 24 is, for example, 10 to 50 mm, and 40.2 mm (0. 2 mm + 8.5 mm + 1.5 mm + 28.5 mm + 1.5 mm).

The coil outer diameter (D ₂₁ ) at the distal end side small diameter portion 21 of the coil spring 20 is usually 0.008 inch (0.203 mm) or less, and 0.0078 inch is a preferable example. When the coil outer diameter (D ₂₁ ) of the distal-side small-diameter portion 21 is 0.008 inches or less, it can be inserted into a narrowed portion having a small hole diameter that cannot be inserted with a conventional guide wire. The treatment of a narrow region (for example, a microchannel having a pore diameter of 250 μm or less in a CTO lesion) that cannot be performed by using a wire becomes possible.

The coil outer diameter (D ₂₃ ) in the middle diameter portion 23 of the coil spring 20 is larger than the coil outer diameter (D ₂₁ ) in the distal end side small diameter portion 21, and preferably 0.009 to 0.011 inch (0.229 to 0.229). 0.279 mm), and a suitable example is 0.010 inch (0.254 mm).

  The presence of the intermediate diameter portion 23 between the front end side small diameter portion 21 and the rear end side large diameter portion 25 allows the front end side small diameter portion 21, the intermediate diameter portion 23, the rear end side large diameter portion 25, and the coil outer diameter to be stepped. There is no portion where the outer diameter of the coil changes suddenly (a portion that tends to be kinked).

The coil outer diameter (D ₂₅ ) in the rear end side large diameter portion 25 of the coil spring 20 is larger than the coil outer diameter (D ₂₃ ) in the medium diameter portion 23 and is usually 0.012 inches or more, and 0.014 inches. (0.356 mm) or more is preferable, and 0.014 inch is a preferable example.

The coil outer diameter (D ₂₅ ) of the rear end side large diameter portion 25 is 0.012 inch or more, and the distal end side small diameter portion 21, the medium diameter portion 23, the rear end side large diameter portion 25 and the coil outer diameter are steps. Therefore, the guide wire of this embodiment provided with such a coil spring 20 has high bending rigidity and excellent pushability.

In the coil spring 20, the ratio (D ₂₁ / D ₂₃ ) of the coil outer diameter of the distal end side small diameter portion 21 to the coil outer diameter of the medium diameter portion 23 is 0.5 to 0.9, and the first taper portion 22 The length (L ₂₂ ) is preferably 0.5 to 10 mm.

When the ratio of the coil outer diameter (D ₂₁ / D ₂₃ ) is less than 0.5 and / or when the length of the first taper portion 22 is less than 0.5 mm, the bending rigidity of the guide wire is There is a risk that the lowering may cause kinking in the vicinity of the first taper portion 22 or the pushability may be impaired.
On the other hand, when the ratio (D ₂₁ / D ₂₃ ) exceeds 0.9 and / or when the length of the first taper portion 22 exceeds 10 mm, the tip side small diameter portion 21 is sufficiently reduced in diameter. May not be able to plan.
A suitable example of the ratio (D ₂₁ / D ₂₃ ) of the coil outer diameter is 0.78 (0.0078 inch / 0.010 inch).

In the coil spring 20, the ratio (D ₂₅ / D ₂₃ ) of the coil outer diameter of the rear end side large diameter portion 25 to the coil outer diameter of the medium diameter portion 23 is 1.1 to 2.3, and the second It is preferable that the length (L ₂₄ ) of the taper portion 24 is 0.5 to 10 mm.

When the ratio (D ₂₅ / D ₂₃ ) of the coil outer diameter of the rear end side large diameter part 25 to the coil outer diameter of the medium diameter part 23 exceeds 2.3 and / or the length of the second taper part 24 is When it is less than 0.5 mm, the bending rigidity of the guide wire is lowered, and there is a risk that the guide wire may be kinked in the vicinity of the second taper portion 24 or the pushability may be impaired.
On the other hand, when the ratio (D ₂₁ / D ₂₃ ) is less than 1.1 and / or when the length of the second taper portion 24 exceeds 10 mm, the medium diameter portion 23 and the distal end side small diameter portion 21 are included. There is a possibility that it is not possible to sufficiently reduce the diameter.
A suitable example of the ratio of the coil outer diameter (D ₂₅ / D ₂₃ ) is 1.4 (0.014 inch / 0.010 inch).

  In the guide wire of the present embodiment, each of the distal end portion of the distal end side small diameter portion 21 of the coil spring 20, the rear end portion of the second taper portion 24, and the rear end portion of the rear end side large diameter portion 25 is made of solder. The core wire 10 is fixed to the outer periphery of the distal end side small diameter portion 11.

As shown in FIG. 1 and FIG. 3A, the distal end portion of the distal-side small diameter portion 21 that is the distal end portion of the coil spring 20 is fixed to the core wire 10 by Au—Sn solder 31.
That is, the Au—Sn based solder 31 penetrates into the tip part of the coil spring 20 (tip part of the tip side small diameter part 21) and comes into contact with the outer periphery of the core wire 10 (distal end side small diameter part 11). The tip of the coil spring 20 is fixed to the core wire 10 (distal end side small diameter portion 11).

As shown in FIG. 3A, the Au—Sn solder 31 penetrates into the coil in a range corresponding to 3 pitches of the coil spring 20.
In addition, a substantially hemispherical tip is formed by Au—Sn solder 31 that has not penetrated into the coil spring 20 at the tip of the coil spring 20.

As a result, the distal end portion of the guide wire according to the present embodiment has a hardened tip portion of the Au—Sn solder 31 [the coil spring 20 (which can no longer be bent freely by the Au—Sn 31 solder penetrating into the coil). The tip portion of the tip side small diameter portion 21) and the tip portion formed by the Au—Sn solder 31 are formed.
The length of the tip rigid portion (the length from the tip of the guide wire to the rear end of the Au—Sn solder 31 penetrating into the coil) (L ₄ ) is 0.1 to 0.5 mm, preferably 0. .3 to 0.4 mm.

When the length of the tip rigid portion is 0.1 mm or more, a sufficient fixing force of the coil spring 20 to the core wire 10 can be ensured.
Further, when the length of the tip rigid portion is 0.5 mm or less, the shaping length (external length (L ₅₂ ) described later) can be 0.7 mm or less.

  In the guide wire of the present embodiment, the Au—Sn solder penetrates into the coil within a range corresponding to 1 to 4 pitches of the coil spring in order to set the length of the tip rigid portion to 0.1 to 0.5 mm. It is preferable.

  The Au—Sn solder used in the guide wire of this embodiment is made of an alloy of, for example, 75 to 80% by mass of Au and 25 to 20% by mass of Sn.

By fixing the stainless steel and platinum (alloy) using Au—Sn solder, the fixing force (about 2.5 times that of fixing using the usual Ag—Sn solder) Tensile strength).
For this reason, even when the length of the tip rigid portion is as short as 0.1 to 0.5 mm (when the penetration range of the solder is 1 to 3 times the coil pitch), the coil spring 20 is fixed to the core wire 10. The strength can be made sufficiently high. Specifically, the strength can be made higher than the tensile breaking strength of the small diameter portion 11 on the distal end side of the core wire 10. For this reason, even if a tensile force is applied between the coil spring 20 and the core wire 10, it is possible to prevent the core wire 10 from being pulled out.
In addition, Au—Sn solder is superior in contrast to Ag—Sn solder.
Furthermore, Au—Sn solder is superior in corrosion resistance to blood and body fluids than Ag—Sn solder.
In addition, it can replace with Au-Sn type solder, and there can exist the same effect as the case where Au-Sn type solder is used also by using another gold-containing solder.
Examples of the gold-containing solder other than the Au—Sn solder include Au alloy solder such as Au—Ge solder, Au—Si solder, Au—In solder, Au—Sb solder, and Au solder.

As shown in FIGS. 1 and 3B, the boundary portion between the first tapered portion 22 and the middle diameter portion 23 of the coil spring 20 is not fixed to the core wire 10 by solder.
As a result, there is no rigid portion due to solder in the region (the tip region of the coil spring) from the tip side small diameter portion 21 (excluding the tip portion) to the second taper portion 24 (excluding the rear end portion). A sufficient flexibility of the guide wire in the region can be ensured.

As shown in FIG. 1 and FIG. 3C, the rear end portion of the second tapered portion 24 of the coil spring 20 is fixed to the core wire 10 with Au—Sn solder 32.
That is, the Au—Sn-based solder 32 penetrates into the rear end portion of the second taper portion 24 and comes into contact with the outer periphery of the core wire 10 (distal end side small diameter portion 11). The rear end portion is fixed to the core wire 10 (distal end side small diameter portion 11).

As shown in FIG. 1 and FIG. 3D, the rear end portion of the rear end side large diameter portion 25 that is the rear end portion of the coil spring 20 is fixed to the core wire 10 by Ag—Sn solder 33. .
That is, the Ag—Sn solder 33 penetrates into the rear end portion of the coil spring 20 (the rear end portion of the rear end side large diameter portion 25), and the outer periphery of the core wire 10 (distal end side small diameter portion 11). By contacting, the rear end portion of the coil spring 20 is fixed to the core wire 10 (distal end side small diameter portion 11).

  In the distal end side small diameter portion 11 of the core wire 10, the outer diameter of the portion to which the rear end side large diameter portion 25 of the coil spring 20 is fixed is the portion to which the tip side small diameter portion 21 of the coil spring 20 is fixed (distal end). Therefore, it is possible to use an Ag—Sn solder having a smaller fixing force than that of the Au—Sn solder.

As shown in FIGS. 1 to 3, in the guide wire of the present embodiment, the inside of the coil spring 20 (inside the solder is not penetrated) is filled with the cured resin 40, and the resin layer made of the cured resin 40. The outer periphery of the coil spring 20 and the tip are covered by 40A.
A hydrophilic resin layer 50 is laminated on the surface of the resin layer 40A.

  By filling the inside of the coil spring 20 with the cured resin 40, the integrity (interlocking) between the core wire 10 and the coil spring 20 is significantly improved. As a result, the torque transmission performance of the guide wire is further improved, and the rotational torque transmitted from the proximal end side large diameter portion 13 of the core wire 10 is distant from the coil spring 20 integrated with the distal end side small diameter portion 11. It is reliably transmitted to the end.

  Further, since the hydrophilic resin layer 50 is formed on the outer periphery of the coil spring 20 via the resin layer 40A (undercoat layer), the hydrophilic resin layer 50 is firmly fixed and lubricated by the hydrophilic resin. Can be stably expressed.

Here, the cured resin 40 that fills the inside of the coil spring 20 and forms the resin layer 40A that covers the outer periphery of the coil spring 20 has good adhesion to both the coil spring 20 and the hydrophilic resin. Specific examples include urethane acrylate resins, polyurethane resins, silicone resins, epoxy resins, acrylic resins, nylon resins, and other photo-curable resins or thermosetting resin cured products. .
The film thickness of the resin layer 40A covering the outer periphery and the tip of the coil spring 20 is, for example, 1 to 100 μm, and preferably 3 to 10 μm.

As the resin constituting the hydrophilic resin layer 50 that is laminated on the surface of the resin layer 40A, any resin that is used in the medical device field can be used.
The thickness of the hydrophilic resin layer 50 is, for example, 1 to 30 μm, preferably 3 to 19 μm.

  As a method of filling the cured resin 40 and forming the resin layer 40A and a method of forming the hydrophilic resin 50 by lamination, for example, the coil spring 20 attached to the core wire 10 is immersed in the curable resin to immerse the coil spring 20. The inside is filled with a curable resin, and a resin layer is formed on the surface of the coil spring 20, and this is thermally cured or photocured to obtain a cured resin 40 (resin layer 40A), and then on the surface of the resin layer 40A. A method of applying a hydrophilic resin by an appropriate means can be mentioned.

According to the guide wire of the present embodiment, the coil spring 20 constituting this has the distal end side small diameter portion 21 whose coil outer diameter (D ₂₁ ) is 0.008 inch or less, so that the conventional guide wire In a narrow region that cannot be inserted with a conventional guidewire (for example, a microchannel with a pore diameter of 250 μm or less in a CTO lesion) that cannot be performed using a conventional guide wire. Treatment becomes possible.

The coil spring 20 has a rear end side large diameter portion having a coil outer diameter (D ₂₅ ) of 0.012 inches or more, a front end side small diameter portion 21, an intermediate diameter portion 23, and a rear end side large diameter portion 25. Since the outer diameter of the coil changes stepwise (the outer diameter of the coil does not change abruptly), the guide wire of this embodiment having such a coil spring 20 has high bending rigidity and pushability. In addition, the torque transmission is excellent.

In the coil spring 20, the ratio (D ₂₁ / D ₂₃ ) of the coil outer diameter of the distal-side small diameter portion 21 to the coil outer diameter of the medium diameter portion 23 is 0.5 to 0.9, and the first taper portion 22 has a length (L ₂₂ ) of 0.5 to 10 mm, and a ratio (D ₂₅ / D ₂₃ ) of the coil outer diameter of the rear end side large diameter portion 25 to the coil outer diameter of the medium diameter portion 23 is 1. 0.1 to 2.3, and the length (L ₂₄ ) of the second taper portion 24 is 0.5 to 10 mm, thereby reducing the diameter of the distal-side small-diameter portion 21 (enlarging a treatable case) ) And the improvement effect of bending rigidity, pushability, and torque transmission can be expressed in a balanced manner.

  Further, since the close-winding portion 201 of the coil spring 20 is configured by the tip-side small-diameter portion 21, the first taper portion 22, the medium-diameter portion 23, and the second taper portion 24, a dense region that is the tip region of the coil spring 20 is formed. Good contrast (visibility) can be expressed in the wound portion 201.

  In addition, since the insertion resistance of the guide wire into the stenosis site varies depending on the coil outer diameter of the coil spring 20, the operator can change the insertion length of the guide wire into the stenosis site according to the present embodiment by changing the coil outer diameter. It can be grasped based on the change (feel) of the accompanying insertion resistance.

Further, since the inside of the coil spring 20 is filled with the cured resin 40, the integrity (interlocking) between the core wire 10 and the coil spring 20 can be improved, and the torque transmission and operability of the guide wire can be further improved. Can be improved.
Further, since the hydrophilic resin layer 50 is laminated on the outer periphery of the coil spring 20 via the resin layer 40A of the cured resin 40, the lubricity by the hydrophilic resin can be stably expressed.

In addition, since Au—Sn based solder is used as the solder for fixing the tip of the coil spring 20 (tip of the tip-side small diameter portion 21) to the core wire 10, the length of the tip rigid portion is 0.1. Despite being as short as ˜0.5 mm, the fixing strength of the coil spring to the core wire (distal end side small diameter portion 11) is sufficiently high, and even if a tensile force acts between the coil spring 20 and the core wire 10, The core wire 10 is not pulled out.
And since the length of the tip rigid portion is as short as 0.1 to 0.5 mm, the shaping length can be shortened, and as a result, the frictional resistance can be sufficiently reduced during operation in the microchannel. it can. In addition, treatment in a narrow region that cannot be performed using a conventional guide wire is also possible.

FIG. 4A shows that the Au—Sn solder penetrates into a range corresponding to two pitches of the small diameter portion (coil wire diameter 50 μm, coil pitch 75 μm, coil outer diameter 0.0078 inch) of the coil spring. The state which shape | molded the front-end | tip part of the guide wire of this embodiment is shown. The length of the rigid portion of the guide wire is 0.25 mm, and the shaping length is 0.35 mm for the inner length (L ₅₁ ) and 0.40 mm for the outer length (L ₅₂ ).

FIG. 4B shows a guide wire in which Ag-Sn solder penetrates into a range corresponding to 6 pitches of the tip of the coil spring (coil wire diameter 50 μm, coil pitch 75 μm, coil outer diameter 0.010 inch). The state which shape | molded the front-end | tip part of is shown. The length of the rigid portion of the guide wire is 0.60 mm, and the shaping length is 0.70 mm for the inner length (L ₅₁ ) and 0.75 mm for the outer length (L ₅₂ ).

The bending angle (θ) of the guide wire of this embodiment is less than 25 °, preferably less than 10 °.
Here, the “bending heel angle (θ)” is measured as follows. That is, as shown in FIG. 5 (1), the tip of the guide wire G (specifically, a portion about 2 mm from the tip including the tip) is fixed by the chuck C, and about 5 mm from the tip of the guide wire G. From the position to the position of 14.5 mm from the tip (length ≒ 9.5 mm ≒ 3.14 x 3 mm), wrap once around the outer circumference of the rod R with a diameter of 3 mm, then hang down, the rear end (lower end ) A 150 g weight W is attached and a tensile load is applied. After 10 seconds, the weight W is removed and the guide wire G released from the chuck C and the rod R is warped at the tip portion (the angle formed by the tangent lines before and after the winding portion) as shown in FIG. ) Is the bending heel angle (θ). It can be said that the smaller the bending wrinkle angle (θ), the harder the permanent deformation occurs.
The guide wire of the present embodiment having a bending heel angle (θ) of less than 25 ° is less likely to be permanently deformed even when bent, and is excellent in shape retention. Therefore, the guide wire passes through a tortuous blood vessel such as a coronary artery system. Excellent operability.
In addition, the high tensile strength (2600-3000 MPa) which the constituent material of the core wire 10 has contributed greatly to such excellent shape retainability (hardness of occurrence of permanent deformation when bent).

According to the guide wire of the present embodiment, it can be inserted into a stenosis site such as a microchannel with a small hole diameter that could not be inserted with a conventional guide wire.
The guide wire of the present embodiment has high bending rigidity (kink resistance), excellent pushability, and good torque transmission (the rotational force at hand is easily transmitted to the tip), so that the blood vessel branch By selection, it is easy to move forward to the target blood vessel and has excellent operability.
In addition, the guide wire of the present embodiment is hardly deformed even when it is bent when passing through a tortuous blood vessel, and has excellent shape retention.

Second Embodiment
The guide wire shown in FIG. 6 has a core wire 10 and a coil spring 20B.
The core wire 10 includes a distal end side small diameter portion 11 that is tapered so as to expand in the proximal direction, a tapered portion 13 that expands in the proximal direction, and a proximal end large diameter portion 14.
The distal end side small diameter portion 11, the taper portion 13, and the proximal end side large diameter portion 14 are integrally configured by the same wire (for example, a round bar member).

The cross section of the taper part 13 and the proximal end side large diameter part 14 is substantially circular.
The cross section on the proximal end side of the distal end side small diameter portion 11 is substantially circular, but the distal end side of the distal end side small diameter portion 11 may be formed into a plate shape by compressing the wire. In that case, the cross section is substantially rectangular.

The core wire 10 is made of high strength austenitic stainless steel (for example, SUS304, SUS316) having a tensile strength of 2600 to 3000 MPa.
A high-strength austenitic stainless steel having a tensile strength of 2600 to 3000 MPa also has a high elastic limit. Therefore, in the guide wire of this embodiment using this as a core wire, it is difficult to cause permanent deformation due to bending.

A water repellent resin layer is formed on the outer peripheral surface of the core wire 10.
As the resin constituting the water-repellent resin layer, any resin that is used for medical purposes and has water repellency can be used, and suitable resins include fluorine-based resins such as PTFE.

As shown in FIG. 7, the total length (L ₁ ) of the guide wire 1 is, for example, 1500 to 3000 mm, and is 1780 mm if a suitable example is shown.
In addition, the outer diameter (D ₁ ) of the proximal end side large-diameter portion 14 is usually 0.012 inches (0.305 mm) or less, preferably 0.010 inches (0.254 mm) or less, more preferably 0. 0.006 to 0.010 inch, and 0.010 inch is a preferable example.

Since the outer diameter (D ₁ ) of the proximal-end-side large-diameter portion 14 is 0.012 inches or less, the medical instrument such as a catheter used with the guide wire of the present invention can be reduced in size and further reduced in invasiveness. Can contribute.

The maximum outer diameter of the distal end side small diameter portion 11 is not particularly limited as long as it is smaller than the inner diameter of the coil spring 20B, but it is 1/5 of the outer diameter (D ₁ ) of the proximal end side large diameter portion 14. About 3/5.

The coil spring 20 </ b> B constituting the guide wire 1 is attached to the outer periphery of the distal end side small diameter portion 11 of the core wire 10 along the axial direction.
The coil spring 20B is composed of a single wire, and the coil pitch is 1.0 to 1.8 times the coil wire diameter, and the tip side densely wound portion 21B, and the coil pitch is 1.8 times the coil wire diameter. The X-ray opaque region is configured by the distal end side densely wound portion 21B and a distal end tip described later.

The coil pitch in the tip side densely wound portion 21B is 1.0 to 1.8 times the coil wire diameter, and is 1.0 times if a suitable example is shown.
The coil pitch in the rear end side loosely wound portion 22B is 1.8 to 2.5 times the coil wire diameter, and is 2.0 times if a suitable example is shown.
As described above, by changing the coil pitch between the front end side and the rear end side, good contrast (visibility) can be expressed in the front end side closely wound portion 21B.
When the same pitch is used over the entire coil spring, the X-ray opaque region becomes longer, resulting in a decrease in visibility.

In FIG. 7, the length (L ₂ ) of the coil spring 20B is, for example, 30 to 800 mm, and 115 mm if a suitable example is shown.
The length (L ₂₁ ) of the tip side densely wound portion 21B is, for example, 10 to 50 mm, and is 30 mm if a suitable example is shown.
The length (L ₂₂ ) of the rear end side loosely wound portion 22B is, for example, 20 to 750 mm, and is 85 mm if a suitable example is shown.
The length (L ₃ + L ₂ ) from the front end of the guide wire 1 to the rear end of the coil spring 20B is, for example, 30 to 800 mm, and 115.2 mm if a suitable example is shown.
The length (L ₃ + L ₂₁ ) from the front end of the guide wire 1 to the rear end of the front end side tightly wound portion 21B is, for example, 10 to 50 mm, and is 30.2 mm if a suitable example is shown.

The coil outer diameter (D ₂ ) of the coil spring 20B is usually 0.012 inch (0.305 mm) or less, preferably 0.010 inch (0.254 mm) or less, more preferably 0.006 to 0.010. Inches are 0.010 inches.

When the outer diameter (D ₁ ) of the proximal end side large diameter portion 14 of the core wire 10 is 0.012 inch or less and the coil outer diameter (D ₂ ) of the coil spring 20B is also 0.012 inch or less, The operability when accessing the microchannel (for example, lubricity in the microchannel) is excellent.
Although the outer diameter of the wire which comprises the coil spring 20B is not specifically limited, Preferably it is 30-90 micrometers, and if it shows a suitable example, it is 60 micrometers.

  As a material of the coil spring 20B, a material (X-ray opaque material) having good contrast with respect to X-rays such as platinum, platinum alloy (for example, Pt / W = 92/8), gold, gold-copper alloy, tungsten, tantalum and the like. ).

  In the guide wire of the present embodiment, each of the front end portion, the rear end portion, and the intermediate portion (the boundary portion between the front end side densely wound portion 21B and the rear end side loosely wound portion 22B) of the coil spring 20B is made of solder. The distal end side small-diameter portion 11 is fixed to the outer periphery.

As shown in FIGS. 6 and 8A, the tip of the coil spring 20B is fixed to the core wire 10 with Au—Sn solder 31.
That is, the Au-Sn solder 31 penetrates into the coil spring 20B, and the Au-Sn solder 31 comes into contact with the outer periphery of the core wire 10 (distal end side small diameter portion 11), whereby the tip of the coil spring 20B. The portion is fixed to the core wire 10 (the distal end side small diameter portion 11).

As shown in FIG. 8A, the Au—Sn solder 31 penetrates into the coil in a range corresponding to two pitches of the coil spring 20B.
In addition, a substantially hemispherical tip is formed by the Au—Sn solder 31 that has not penetrated into the coil spring 20B at the tip of the coil spring 20B.

As a result, the distal end portion of the guide wire 1 of the present embodiment has a hardened tip portion of the Au—Sn solder 31 (coil spring 20B that can no longer be freely bent by the Au—Sn 31 solder that has penetrated into the coil. And a tip portion formed by the Au—Sn solder 31).
The length of the rigid portion of the tip (the length from the tip of the guide wire 1 to the rear end of the Au—Sn solder 31 penetrating into the coil) (L ₄ ) is about 0.3 to 0.4 mm.

In the guide wire of the present invention, the length of the distal rigid portion is 0.1 to 0.5 mm. When the length of the tip rigid portion is less than 0.1 mm, it is not possible to sufficiently secure the fixing force of the coil spring to the core wire.
On the other hand, when the length of the tip rigid portion exceeds 0.5 mm, the shaping length (the outer length (L ₅₂ ) described later) cannot be 0.7 mm or less.

  In the guide wire of the present invention, the coil pitch at the tip of the coil spring is 1.0 to 1.8 times the coil wire diameter in order to make the length of the tip rigid portion 0.1 to 0.5 mm. In addition, it is preferable that the Au—Sn solder penetrates into the coil in a range corresponding to 1 to 3 pitches of the coil spring.

The medical guide wire of the present invention is characterized in that Au—Sn solder is used as solder for fixing the tip of the coil spring to the core wire.
The Au—Sn solder used in the present invention is made of, for example, an alloy of 75 to 80% by mass of Au and 25 to 20% by mass of Sn.

By fixing the stainless steel and platinum (alloy) using Au-Sn solder, the adhesive strength (tensile strength) is about 2.5 times that of the case of fixing with Ag-Sn solder. It is done.
For this reason, even when the length of the tip rigid portion is as short as 0.1 to 0.5 mm (when the penetration range of the solder is 1 to 3 times the coil pitch), the coil spring 20B is fixed to the core wire 10. The strength can be made sufficiently high. Specifically, the strength can be made higher than the tensile breaking strength of the small diameter portion 11 on the distal end side of the core wire 10. For this reason, even if a tensile force is applied between the coil spring 20B and the core wire 10, it is possible to prevent the core wire 10 from being pulled out.
In addition, Au—Sn solder is superior in contrast to Ag—Sn solder.
Furthermore, Au—Sn solder is superior in corrosion resistance to blood and body fluids than Ag—Sn solder.

As shown in FIG. 6 and FIG. 8 (B), an intermediate portion including a boundary region between the front end side densely wound portion 21B and the rear end side loosely wound portion 22B of the coil spring 20B is made of a core wire by an Au—Sn solder 32 10 is fixed.
That is, the Au—Sn based solder 32 penetrates into the coil spring 20B, and the Au—Sn based solder 32 comes into contact with the outer periphery of the core wire 10 (distal end side small diameter portion 11). The intermediate part is fixed to the core wire 10 (distal end side small diameter part 11).
Stress concentration is likely to occur in the boundary region between the front end side densely wound portion 21B and the rear end side loosely wound portion 22B, and the intermediate portion including this boundary region is fixed with an Au—Sn solder having a high fixing force, thereby obtaining a coil. The fixing strength of the spring 20B can be further improved.

As shown in FIGS. 6 and 8C, the rear end portion of the coil spring 20B is fixed to the core wire 10 with Ag—Sn solder 33.
That is, the Ag-Sn solder 33 penetrates into the coil spring 20B, and the Ag-Sn solder 33 comes into contact with the outer periphery of the core wire 10 (distal end side small-diameter portion 11). The rear end portion is fixed to the core wire 10 (distal end side small diameter portion 11).
In the distal end side small diameter portion 11 of the core wire 10, the outer diameter of the portion to which the rear end portion of the coil spring 20B is fixed is larger than the outer diameter of the portion (distal end) to which the tip portion of the coil spring 20B is fixed (relative). Therefore, it is possible to use an Ag—Sn solder having a smaller fixing force than that of the Au—Sn solder.

As shown in FIGS. 6 to 8, the guide wire 1 of the present embodiment is filled with a cured resin 40 inside the coil spring 20 </ b> B, and the outer periphery of the coil spring 20 </ b> B is formed by the resin layer 40 </ b> A of the cured resin 40. And the tip is covered.
A hydrophilic resin layer 50 is laminated on the surface of the resin layer 40A.

  By filling the inside of the coil spring 20B with the cured resin 40, the core wire 10 and the coil spring 20B are integrated, the torque transmission performance of the guide wire is greatly improved, and the proximal end side large diameter of the core wire 10 is increased. The rotational torque transmitted from the portion 14 is reliably transmitted to the distal end of the coil spring 20B integrated with the distal end side small diameter portion 11.

  Further, since the hydrophilic resin layer 50 is formed on the outer periphery of the coil spring 20B via the resin layer 40A (undercoat layer), the hydrophilic resin layer 50 is firmly fixed and lubricated by the hydrophilic resin. Can be stably expressed.

Here, the cured resin 40 constituting the resin layer 40A that fills the inside of the coil spring 20B and covers the outer periphery of the coil spring 20B has good adhesion to both the coil spring 20B and the hydrophilic resin. Specific examples include urethane acrylate resins, polyurethane resins, silicone resins, epoxy resins, acrylic resins, nylon resins, and other photo-curable resins or thermosetting resin cured products. .
The film thickness of the resin layer 40A covering the outer periphery and the tip of the coil spring 20B is, for example, 1 to 100 μm, and preferably 3 to 10 μm.

As the resin constituting the hydrophilic resin layer laminated on the surface of the resin layer 40A, any resin used in the medical device field can be used.
The thickness of the hydrophilic resin layer 50 is, for example, 1 to 30 μm, preferably 3 to 19 μm.

  As a method for filling the cured resin 40 and forming the resin layer 40A and a method for forming the hydrophilic resin 50 by lamination, for example, the coil spring 20B attached to the core wire 10 is immersed in the curable resin, thereby forming the coil spring 20B. The inside is filled with a curable resin, and a resin layer is formed on the surface of the coil spring 20B, and this is thermally cured or photocured to obtain a cured resin 40 (resin layer 40A), and then on the surface of the resin layer 40A. A method of applying a hydrophilic resin by an appropriate means can be mentioned.

According to the guide wire 1 of the present embodiment, since the Au—Sn solder is used as the solder for fixing the tip of the coil spring 20B to the core wire 10, the proximal end side large diameter portion 14 of the core wire 10 is used. Strength of the coil spring to the core wire (the distal end side small diameter portion 11) despite the fact that the outer diameter of the wire is as thin as 0.012 inches or less and the length of the tip rigid portion is as short as 0.3 to 0.4 mm. Is sufficiently high, and even if a tensile force is applied between the coil spring 20B and the core wire 10, the core wire 10 is not pulled out.
And since the length of the tip rigid portion is as short as 0.3 to 0.4 mm, the shaping length can be shortened, and as a result, the frictional resistance can be sufficiently reduced during operation in the microchannel. it can. In addition, treatment in a narrow region that cannot be performed using a conventional guide wire is also possible.

Further, since the inside of the coil spring 20B is filled with the cured resin 40, the core wire 10 and the coil spring 20B can be integrated, and the torque transmission performance and operability of the guide wire 1 can be significantly improved. it can.
Further, since the hydrophilic resin layer 50 is laminated on the outer periphery of the coil spring 20B via the resin layer 40A of the cured resin 40, the lubricity by the hydrophilic resin can be stably expressed.

  In addition, since the coil spring 20B includes the front end side densely wound portion 21B and the rear end side loosely wound portion 22B, good contrast (visibility) can be expressed in the front end side closely wound portion 21B.

The bending angle (θ) of the guide wire of this embodiment is less than 25 °, preferably less than 10 °.
The guide wire of the present embodiment having a bending heel angle (θ) of less than 25 ° is less likely to be permanently deformed even when bent, and is excellent in shape retention. Therefore, the guide wire passes through a tortuous blood vessel such as a coronary artery system. Excellent operability.

  The guide wire of this embodiment has high bending rigidity (kink resistance), excellent pushability, and good torque transmission. Therefore, it is easy to move forward to the target blood vessel by selecting blood vessel branching. Excellent in properties. In addition, the guide wire of the present embodiment is hardly deformed even when it is bent when passing through a tortuous blood vessel, and has excellent shape retention.

<Third Embodiment>
The guide wire shown in FIG. 9 has a core wire 10 and a coil spring 20C.
The core wire 10 includes a distal end side small diameter portion 11 that is tapered so as to expand in the proximal direction, a tapered portion 13 that expands in the proximal direction, and a proximal end large diameter portion 14.
The distal end side small diameter portion 11, the taper portion 13, and the proximal end side large diameter portion 14 are integrally configured by the same wire (for example, a round bar member).

The cross section of the taper part 13 and the proximal end side large diameter part 14 is substantially circular.
The cross section on the proximal end side of the distal end side small diameter portion 11 is substantially circular, but the distal end side of the distal end side small diameter portion 11 may be formed into a plate shape by compressing the wire. In that case, the cross section is substantially rectangular.

The core wire 10 is made of high strength austenitic stainless steel (for example, SUS304, SUS316) having a tensile strength of 2600 to 3000 MPa.
A high-strength austenitic stainless steel having a tensile strength of 2600 to 3000 MPa also has a high elastic limit. Therefore, in the guide wire of this embodiment using this as a core wire, it is difficult to cause permanent deformation due to bending.

A water repellent resin layer (not shown) is formed on the outer peripheral surface of the core wire 10.
As the resin constituting the water-repellent resin layer, any resin that is used for medical purposes and has water repellency can be used, and suitable resins include fluorine-based resins such as PTFE.

As shown in FIG. 10, the total length (L ₁ ) of the guide wire is, for example, 1500 to 3000 mm, and is 1780 mm if a suitable example is shown.
The outer diameter (D ₁ ) of the proximal end side large-diameter portion 14 of the core wire 10 is preferably 0.014 inch (0.356 mm) or more, and 0.014 inch is a preferable example.

The maximum outer diameter of the distal end side small diameter portion 11 is not particularly limited as long as it is smaller than the inner diameter of the coil spring 20C, but it is 1/5 of the outer diameter (D ₁ ) of the proximal end side large diameter portion 14. It is preferably about ˜3 / 5.

The coil spring 20 </ b> C constituting the guide wire is composed of one wire, and is attached to the outer periphery of the distal end side small diameter portion 11 of the core wire 10 along the axial direction.
The coil spring 20C includes a front end side small diameter portion 21C, a tapered portion 22C, and a rear end side large diameter portion 23C.

  In the present embodiment, the distal end side small diameter portion 21C and the tapered portion 22C are formed from the distal end side densely wound portion 201, and the rear end side large diameter portion 23C is formed from the rear end side loosely wound portion 202. The tip-side densely wound portion 201 (tip-side small-diameter portion 21C and tapered portion 22C) and the tip that will be described later constitute an X-ray opaque region.

The coil pitch in the tip side densely wound portion 201 is 1.0 to 1.8 times the coil wire diameter, and is 1.3 times as long as a suitable example is shown.
The coil pitch in the rear end side loosely wound portion 202 is 1.8 to 3.0 times the coil wire diameter, and is 3.0 times if a suitable example is shown.
As described above, by changing the coil pitch between the front end side and the rear end side, good contrast (visibility) can be expressed in the front end side closely wound portion 201.
When the same pitch is used over the entire coil spring, the X-ray opaque region becomes longer, resulting in a decrease in visibility.

In FIG. 10, the length (L ₂ ) of the coil spring 20C is, for example, 30 to 800 mm, preferably 100 to 200 mm, and 165 mm if a suitable example is shown.
The length (L ₂₁ ) of the distal end side small diameter portion 21C is 5 to 100 mm, preferably 10 to 70 mm, and 38.5 mm if a suitable example is shown.
When the length (L ₂₁ ) of the distal-side small diameter portion 21C is 5 mm or more, the distal-side small diameter portion 21C can be inserted into most microchannels.
When the length (L ₂₁ ) of the distal-side small-diameter portion 21C is 100 mm or less, the length of the rear-end-side large-diameter portion 23C that contributes to improvement in bending rigidity and torque transmission can be sufficiently secured.
The length (L ₂₂ ) of the tapered portion 22C is, for example, 0.5 to 10 mm, and is 1.5 mm if a suitable example is shown.
The length (L ₂₃ ) of the rear end side large diameter portion 23C is, for example, 85 to 154.5 mm, and is 125 mm if a suitable example is shown.

The length (L ₃ + L ₂ ) from the front end of the guide wire to the rear end of the coil spring 20C is, for example, 30 to 800 mm, and is 165.2 mm if a suitable example is shown.
The length (L ₃ + L ₂₁ + L ₂₂ ) from the front end of the guide wire to the rear end of the tapered portion 22C is, for example, 10 to 50 mm, and is 40.2 mm if a suitable example is shown.

The coil outer diameter (D ₂₁ ) at the small diameter portion 21C on the distal end side of the coil spring 20C is usually 0.012 inches (0.305 mm) or less, preferably 0.010 inches (0.254 mm) or less, more preferably 0. 0.006 to 0.010 inch, and 0.010 inch is a preferable example.

When the coil outer diameter (D ₂₁ ) of the distal-side small diameter portion 21C is 0.012 inch or less, the operability when accessing the microchannel (for example, lubricity in the microchannel) is excellent.

The coil outer diameter (D ₂₃ ) in the large diameter portion 23C on the rear end side of the coil spring 20C is preferably 0.014 inch (0.356 mm) or more, and 0.014 inch as a suitable example.

When the coil outer diameter (D ₂₃ ) of the rear end side large-diameter portion 23C is 0.014 inch or more, sufficient bending rigidity (push transmission at the time of insertion / delivery performance of the device after insertion) is provided for the guide wire. In addition, the guide wire (the guide wire of the present embodiment) is excellent in torque transmission.
The ratio (D ₂₃ / D ₂₁ ) of the coil outer diameter between the rear end side large diameter portion 23C and the front end side small diameter portion 21C is preferably 1.1 to 2.3. .4.

Although the outer diameter of the wire which comprises the coil spring 20C is not specifically limited, Preferably it is 30-90 micrometers, and if it shows a suitable example, it is 60 micrometers.
As a material of the coil spring 20C, a material (X-ray opaque material) having good contrast with respect to X-rays such as platinum, platinum alloy (for example, Pt / W = 92/8), gold, gold-copper alloy, tungsten, tantalum, etc. ).

  In the guide wire of this embodiment, each of the distal end side small diameter portion 21C, the tapered portion 22C and the rear end side large diameter portion 23C of the coil spring 20C is fixed to the outer periphery of the distal end side small diameter portion 11 of the core wire 10 by solder. Has been.

As shown in FIGS. 9 and 11A, the distal end portion of the distal-side small diameter portion 21C, which is the distal end portion of the coil spring 20C, is fixed to the core wire 10 with Au—Sn solder 31.
That is, the Au—Sn based solder 31 penetrates into the tip part of the coil spring 20C (tip part of the tip side small diameter part 21C) and comes into contact with the outer periphery of the core wire 10 (distal end side small diameter part 11). The tip of the coil spring 20C is fixed to the core wire 10 (the distal end side small diameter portion 11).

As shown in FIG. 11 (A), the Au—Sn solder 31 penetrates into the coil in a range corresponding to approximately two pitches of the coil spring 20C.
Also, a substantially hemispherical tip is formed by the Au-Sn solder 31 that has not penetrated into the coil spring 20C at the tip of the coil spring 20C.

As a result, the distal end portion of the guide wire according to the present embodiment has a hardened tip portion of the Au-Sn solder 31 [coil spring 20C (which can no longer be bent freely by the Au-Sn 31 solder penetrating into the coil). A rigid portion formed by a tip portion of the tip-side small diameter portion 21C) and a tip tip formed of the Au-Sn solder 31 is formed.
The length of the tip rigid portion (the length from the tip of the guide wire to the rear end of the Au—Sn solder 31 penetrating into the coil) (L ₄ ) is about 0.3 to 0.4 mm.

In the guide wire of the present invention, the length of the distal rigid portion is 0.1 to 0.5 mm. When the length of the tip rigid portion is less than 0.1 mm, it is not possible to sufficiently secure the fixing force of the coil spring to the core wire.
On the other hand, when the length of the tip rigid portion exceeds 0.5 mm, the shaping length (the outer length (L ₅₂ ) described later) cannot be 0.7 mm or less.

  In the guide wire of the present invention, the coil pitch at the distal-side small-diameter portion 21C of the coil spring is 1.0 to 1.8 of the coil wire diameter so that the length of the distal-end rigid portion is 0.1 to 0.5 mm. It is preferable that the Au-Sn solder penetrates inside the coil in a range corresponding to 1 to 3 pitches of the coil spring.

The medical guide wire of the present invention is characterized in that Au—Sn solder is used as a solder for fixing the small diameter portion of the distal end side of the coil spring to the core wire.
The Au—Sn solder used in the present invention is made of, for example, an alloy of 75 to 80% by mass of Au and 25 to 20% by mass of Sn.

By fixing the stainless steel and platinum (alloy) using Au-Sn solder, the adhesive strength (tensile strength) is about 2.5 times that of the case of fixing with Ag-Sn solder. It is done.
For this reason, even when the length of the tip rigid portion is as short as 0.1 to 0.5 mm (when the penetration range of the solder is 1 to 3 times the coil pitch), the coil spring 20C is fixed to the core wire 10. The strength can be made sufficiently high. Specifically, the strength can be made higher than the tensile breaking strength of the small diameter portion 11 on the distal end side of the core wire 10. For this reason, even if a tensile force is applied between the coil spring 20 </ b> C and the core wire 10, the core wire 10 can be prevented from being pulled out.
In addition, Au—Sn solder is superior in contrast to Ag—Sn solder.
Furthermore, Au—Sn solder is superior in corrosion resistance to blood and body fluids than Ag—Sn solder.

As shown in FIGS. 9 and 11B, the rear end portion of the tapered portion 22 </ b> C of the coil spring 20 </ b> C is fixed to the core wire 10 with Au—Sn solder 32.
That is, the Au—Sn-based solder 32 penetrates into the inside of the rear end portion of the tapered portion 22C and comes into contact with the outer periphery of the core wire 10 (distal end side small diameter portion 11). It is fixed to the core wire 10 (distal end side small diameter portion 11).

As shown in FIGS. 9 and 11C, the rear end portion of the rear end side large diameter portion 23C, which is the rear end portion of the coil spring 20C, is fixed to the core wire 10 with Ag-Sn solder 33. .
That is, the Ag-Sn solder 33 penetrates into the rear end portion (rear end portion of the rear end side large diameter portion 23C) of the coil spring 20C, and the outer periphery of the core wire 10 (distal end side small diameter portion 11). By contacting, the rear end portion of the coil spring 20C is fixed to the core wire 10 (distal end side small diameter portion 11).

  In the distal end side small diameter portion 11 of the core wire 10, the outer diameter of the portion to which the rear end side large diameter portion 23C of the coil spring 20C is fixed is the portion (distal end) to which the tip side small diameter portion 21C of the coil spring 20C is fixed. Therefore, it is possible to use an Ag—Sn solder having a smaller fixing force than that of the Au—Sn solder.

As shown in FIGS. 9 to 11, in the guide wire of the present embodiment, the inside of the coil spring 20 </ b> C (inside the solder does not penetrate) is filled with the cured resin 40 and the resin layer made of the cured resin 40. 40A covers the outer periphery and tip of the coil spring 20C.
A hydrophilic resin layer 50 is laminated on the surface of the resin layer 40A.

  By filling the inside of the coil spring 20C with the cured resin 40, the integrity (interlocking) between the core wire 10 and the coil spring 20C is remarkably improved. As a result, the torque transmission performance of the guide wire is further improved, and the rotational torque transmitted from the proximal end side large diameter portion 14 of the core wire 10 is distant from the coil spring 20C integrated with the distal end side small diameter portion 11. It is reliably transmitted to the end.

  Further, since the hydrophilic resin layer 50 is formed on the outer periphery of the coil spring 20C via the resin layer 40A (undercoat layer), the hydrophilic resin layer 50 is firmly fixed and lubricated by the hydrophilic resin. Can be stably expressed.

Here, the cured resin 40 constituting the resin layer 40A that fills the inside of the coil spring 20C and covers the outer periphery of the coil spring 20C has good adhesion to both the coil spring 20C and the hydrophilic resin. Specific examples include urethane acrylate resins, polyurethane resins, silicone resins, epoxy resins, acrylic resins, nylon resins, and other photo-curable resins or thermosetting resin cured products. .
The film thickness of the resin layer 40A that covers the outer periphery and the tip of the coil spring 20C is, for example, 1 to 100 μm, and preferably 3 to 10 μm.

As the resin constituting the hydrophilic resin layer 50 that is laminated on the surface of the resin layer 40A, any resin that is used in the medical device field can be used.
The thickness of the hydrophilic resin layer 50 is, for example, 1 to 30 μm, preferably 3 to 19 μm.

  As a method of filling the cured resin 40 and forming the resin layer 40A and a method of forming the hydrophilic resin 50 by lamination, for example, by immersing the coil spring 20C attached to the core wire 10 in the curable resin, The inside is filled with a curable resin, and a resin layer is formed on the surface of the coil spring 20C. This is thermally cured or photocured to obtain a cured resin 40 (resin layer 40A), and then on the surface of the resin layer 40A. A method of applying a hydrophilic resin by an appropriate means can be mentioned.

The outer periphery of the tapered portion 22C of the coil spring 20C is covered with resin (the resin layer 40A and the hydrophilic resin layer 50), thereby forming a taper as a guide wire shape.
Here, the starting point of this taper is on the distal end side (position indicated by T ₁ in FIG. 10) from the tip of the taper portion 22C, and the end point of the taper is the proximal end than the rear end of the taper portion 22C. It is on the side (position indicated by T ₂ in FIG. 10). That is, the taper as the shape of the guide wire has a taper angle smaller than the taper angle of the taper portion 22C, and the taper length (L ₅ ) is longer than the length (L ₂₂ ) of the taper portion 22C. ing.

Thus, by covering the tapered portion 22C with resin, the taper shape as the guide wire is made gentler than the taper of the tapered portion 22C, so that the guide wire can be inserted more smoothly.
In FIG. 10, when the length (L ₂₂ ) of the tapered portion 22C is, for example, about 1.5 mm, it is preferable to set the taper length (L ₅ ) of the guide wire to about 5-6 mm.

According to the guide wire of the present embodiment, since the Au—Sn solder is used as the solder for fixing the distal end portion of the coil spring 20C (the distal end portion of the distal-side small diameter portion 21C) to the core wire 10, the distal end stiffness Although the length of the portion is as short as 0.3 to 0.4 mm, the fixing strength of the coil spring to the core wire (distal end side small diameter portion 11) is sufficiently high, and between the coil spring 20C and the core wire 10 Even if a tensile force is applied, the core wire 10 is not pulled out.
And since the length of the tip rigid portion is as short as 0.3 to 0.4 mm, the shaping length can be shortened, and as a result, the frictional resistance can be sufficiently reduced during operation in the microchannel. it can. In addition, treatment in a narrow region that cannot be performed using a conventional guide wire is also possible.

Further, since the coil outer diameter (D ₂₁ ) of the small diameter portion 21C on the distal end side of the coil spring 20C is as small as 0.012 inches or less, operability when accessing the microchannel (for example, lubrication in the microchannel). Property).
Moreover, the outer diameter (D ₁ ) of the proximal end side large diameter portion 14 of the core wire 10 and the coil outer diameter (D ₂₃ ) of the rear end side large diameter portion 23C are both 0.014 inches or more, Sufficient bending rigidity (push transmission at the time of insertion / delivery performance of the device after insertion) is imparted to the guide wire, and this guide wire (guide wire of the present embodiment) also has excellent torque transmission.

Further, since the cured resin 40 is filled in the coil spring 20C, the integrity (interlocking) between the core wire 10 and the coil spring 20C can be improved, and the torque transmission and operability of the guide wire can be further improved. Can be improved.
Further, since the hydrophilic resin layer 50 is laminated on the outer periphery of the coil spring 20C via the resin layer 40A of the cured resin 40, the lubricity by the hydrophilic resin can be stably expressed.

  Further, since the coil spring 20C is composed of the front end side densely wound portion 201 constituting the front end side small diameter portion 21C and the tapered portion 22C and the rear end side loosely wound portion 202 constituting the rear end side large diameter portion 23C, Good contrast (visibility) can be developed in the distal-side small-diameter portion 21C and the tapered portion 22C configured by the side densely wound portion 201.

The bending angle (θ) of the guide wire of this embodiment is less than 25 °, preferably less than 10 °.
The guide wire of the present embodiment having a bending heel angle (θ) of less than 25 ° is less likely to be permanently deformed even when bent, and is excellent in shape retention. Therefore, the guide wire passes through a tortuous blood vessel such as a coronary artery system. Excellent operability.

  The guide wire of this embodiment has high bending rigidity (kink resistance), excellent pushability, and good torque transmission. Therefore, it is easy to move forward to the target blood vessel by selecting blood vessel branching. Excellent in properties. In addition, the guide wire of the present embodiment is hardly deformed even when it is bent when passing through a tortuous blood vessel, and has excellent shape retention.

<Example 1>
Core wire 10 (covered with PTFE) made of austenitic stainless steel (SUS304) having a tensile strength of 2800 MPa after being subjected to an aging treatment at 300 to 500 ° C. for 0.5 to 4 hours. A coil spring 20 was attached to the distal end side small diameter portion 11 of the core wire), and six guide wires of the present invention having a structure as shown in FIGS.

(1) Proximal end side large diameter portion 14:
・ Outer diameter: 0.014 inch (0.356 mm)
・ Length: 1665mm
(2) Tapered portion 13:
・ Maximum outer diameter: 0.014 inches ・ Minimum outer diameter: 0.008 inches ・ Length: 70 mm
(3) Distal end side small diameter part 11:
・ Continuous taper shape ・ Maximum outer diameter: 0.008 inches ・ Minimum outer diameter: 0.0017 inches ・ Length: 165 mm

Here, the coil spring 20 is made of a platinum wire having an outer diameter (coil wire diameter) of 50 μm, the coil outer diameter (D ₂₁ ) of the distal end side small diameter portion 21 is 0.0078 inch, and the length (L ₂₁ ) is. 8.5 mm, the length (L ₂₂ ) of the first taper portion 22 is 1.5 mm, the coil outer diameter (D ₂₃ ) of the medium diameter portion 23 is 0.010 inches, the length (L ₂₃ ) is 28.5 mm, The length (L ₂₄ ) of the second taper portion 24 is 1.5 mm, the coil outer diameter (D ₂₅ ) of the rear end side large diameter portion 25 is 0.014 inch, and the length (L ₂₅ ) is 125 mm, The coil pitch of the closely wound portion 201 formed by the tip side small diameter portion 21, the first taper portion 22, the medium diameter portion 23, and the second taper portion 24 is 75 μm (1.5 times the coil wire diameter, the coil separation distance). Is 25 μm), and the coil pitch of the coarsely wound portion 202 constituted by the rear end side large diameter portion 25 150 [mu] m (3 times the coil wire diameter, the distance of the coil 100 [mu] m) was used for.
The distal end portion of the small-diameter portion 21 on the distal end side of the coil spring 20 and the rear end portion of the second tapered portion are fixed to the core wire 10 using Au—Sn solder, and the rear end of the large-diameter portion 25 on the rear end side. The portion was fixed to the core wire 10 using Ag—Sn solder.

In each of the six guide wires, the coil pitch number (abbreviated as “pitch number” in Table 1) corresponding to the region (length) in which the solder has penetrated inside the coil is one of 1 to 4. I did it. Table 1 shows the length of the tip rigid portion.
In addition, after the coil spring is mounted on the core wire, the inside of the coil spring is filled with a cured resin (urethane acrylate resin), and a resin layer is formed on the outer periphery of the coil spring from the polyethylene oxide on the surface of the resin layer. The resulting hydrophilic resin layer was laminated.

<Comparative Example 1>
The coil spring is made of a platinum wire having an outer diameter of 50 μm, the outer diameter of the coil is 0.0078 inches, the length is 38.5 mm at the distal end side small diameter portion, and the distal end side small diameter portion is 1.5 mm long. And a coiled outer portion having a coil outer diameter of 0.014 inches and a length of the rear end side large diameter portion of 125 mm, and a close winding comprising a tip end small diameter portion and a taper portion. The coil pitch in the part is 75 μm, the coil pitch in the coarse winding part constituted by the rear end side large diameter part is 150 μm, the tip part of the small diameter part on the tip side of this coil spring and the rear end part of the taper part are used. secured to the core wire by using the au-Sn based solder, except that the rear end of the rear end large diameter portion fixed to the core wire by using Ag-Sn based solder in the same manner as in example 1, the tip A coil spring made of a small-diameter portion and a tapered portion and a rear end large-diameter portion to produce six guide wire for comparison composed mounted on the distal end side small-diameter portion of the core wire.

<Comparative example 2>
Six comparative guide wires were produced in the same manner as in Example 1 except that a core wire made of austenitic stainless steel (SUS304) having a tensile strength of 2400 MPa was used.

(2) Guide wire tip load:
For each of the guidewires obtained in Example 1 and Comparative Example 1, the maximum when a portion 10 mm from the tip was bent with the tip tip in contact with the electronic balance (amount of deflection: 0.5 mm) The load was measured. If the maximum load (described as “tip load” in Table 1) is in the range of 0.5 to 1.0 gf, the tip portion of the guide wire has both good bending rigidity and flexibility. I can say that. The results are shown in Table 1 below.

(3) Minimum shaping length and adherence of guide wire:
The minimum shaping length (minimum bendable length) was measured for each of the guidewires obtained in Example 1 and Comparative Example 1.
The measurement of the minimum shaping length was performed for the inner length (L ₅₁ ) and the outer length (L ₅₂ ) as shown in FIG.
Further, a tensile force was applied between the coil spring and the core wire, and the fractured portion was observed to evaluate the fixing property. The evaluation criteria were “◯” when the distal end side small diameter portion of the core wire was broken, and “X” when peeling occurred between the coil spring or the distal end side small diameter portion and the solder. If there is even one “x”, it cannot be made into a product. The results are also shown in Table 1 below.

(4) Bending angle (θ):
The bending wrinkle angle (θ) of each of the guidewires obtained in Example 1 and Comparative Example 2 was measured by the above-described method. As a result, the bending wrinkle angle (θ) of the guidewires (6 pieces) according to Comparative Example 2 was measured. Is 26 to 30 °, whereas the bend angle (θ) of the guidewires (six pieces) according to Example 1 is as small as 7 to 10 °, and it has excellent shape retention that hardly causes permanent deformation. It was.

(5) Torque transmission:
Each of the guide wires obtained in Example 1 and Comparative Example 2 is inserted into a jig simulating the human coronary artery shown in FIG. 12, and the proximal end (hand side) of the guide wire is moved by a motor. The tip was rotated at a predetermined proximal angle of 720 degrees, and the tip rotation angle (twist angle) at the distal end (tip) of the guide wire was examined. The results are shown in FIG. The closer to the theoretical line shown in FIG. 13, the better the torque transmission and the better the operability. When the torque transmission is good, the rotational force on the proximal side is easily transmitted to the tip, and it becomes easy to advance to the target blood vessel by selecting the blood vessel branch, and the insertion workability is improved.

DESCRIPTION OF SYMBOLS 10 Core wire 11 Distal end side small diameter part 12 Tapered part 13 Proximal end side large diameter part 20 Coil spring 21 Tip side small diameter part 22 1st taper part 23 Medium diameter part 24 2nd taper part 25 Rear end side large diameter part 201 Closely wound portion 202 Sparsely wound portion 31 Au—Sn solder 32 Au—Sn solder 33 Ag—Sn solder 40 Cured resin 40A Resin layer 50 Hydrophilic resin layer

Claims (7)

A core wire made of austenitic stainless steel having a tensile strength of 2600 to 3000 MPa, and having a proximal end side large diameter portion and a distal end side small diameter portion having an outer diameter smaller than the proximal end side large diameter portion;
A coil spring that is mounted along the axial direction on the outer periphery of the small-diameter portion on the distal end side of the core wire, and that is fixed to the core wire at least at the front end portion and the rear end portion;
The coil spring is
A tip-side small diameter portion having a coil outer diameter of 0.008 inch ( 0.203 mm ) or less;
A medium diameter portion having a coil outer diameter larger than the coil outer diameter of the tip side small diameter portion;
A rear end side large-diameter portion having a coil outer diameter of 0.012 inch (0.305 mm) or more and larger than the coil outer diameter of the medium-diameter portion;
A first taper portion located between the tip side small diameter portion and the medium diameter portion;
A second taper portion located between the medium diameter portion and the rear end side large diameter portion;
When a 150 gf tensile load is applied for 10 seconds with the small diameter portion of the core wire to which the coil spring is fixed wound once along the outer periphery of a rod having a diameter of 3 mm, the tip portion of the core wire is wound. A medical guide wire having a warp angle of less than 25 °. The proximal end side large diameter portion, which is made of austenitic stainless steel having a tensile strength of 2600 to 3000 MPa and has an outer diameter of 0.012 inches (0.305 mm) or more, and an outer diameter from the proximal end side large diameter portion A core wire having a small distal end small diameter portion;
Attached along the outer circumference of the small-diameter portion on the distal end side of the core wire along the axial direction, a closely wound portion having a coil pitch 1.1 to 2.0 times the coil wire diameter, and continuous to the closely wound portion, A coil spring comprising a coarsely wound portion having a coil pitch exceeding 2.0 times the coil wire diameter;
The coil spring is
A tip-side small diameter portion having a coil outer diameter of 0.008 inch ( 0.203 mm ) or less;
A medium diameter portion having a coil outer diameter larger than the coil outer diameter of the tip side small diameter portion;
A rear end side large-diameter portion having a coil outer diameter of 0.012 inches (0.305 mm) or more and larger than the coil outer diameter of the medium-diameter portion;
A first taper portion located between the tip side small diameter portion and the medium diameter portion;
A second taper portion located between the medium diameter portion and the rear end side large diameter portion;
The tightly wound portion having a length of 5.5 to 110 mm is constituted by the distal end side small diameter portion, the first taper portion, the medium diameter portion, and the second taper portion, and the rear end side large diameter. The sparsely wound portion is constituted by a portion;
The distal end portion of the distal end side small diameter portion, the rear end portion of the second tapered portion, and the rear end portion of the rear end side large diameter portion are fixed to the outer periphery of the distal end side small diameter portion of the core wire by solder,
When a 150 gf tensile load is applied for 10 seconds with the small-diameter portion on the distal end side of the core wire to which the coil spring is fixed wound once along the outer periphery of a rod having a diameter of 3 mm, The medical guide wire according to claim 1, wherein a warp angle is less than 25 °. The outer diameter of the large diameter portion on the proximal end side of the core wire is 0.014 inch (0.356 mm) or more,
The coil outer diameter of the small diameter portion on the tip side of the coil spring is 0.008 inch ( 0.203 mm ) or less,
The outer diameter of the coil of the middle diameter portion is 0.009 to 0.011 inch (0.229 to 0.279 mm ) ,
The medical guide wire according to claim 2, wherein an outer diameter of the coil at the rear end side large diameter portion is 0.014 inch (0.356 mm) or more. The ratio of the coil outer diameter of the tip side small diameter part to the coil outer diameter of the medium diameter part is 0.5 to 0.9, and the length of the first taper part is 0.5 to 10 mm,
The ratio of the coil outer diameter of the rear end side large diameter portion to the coil outer diameter of the medium diameter portion is 1.1 to 2.3, and the length of the second taper portion is 0.5 to 10 mm. A medical guide wire according to claim 3. The tip portion of the tip side small diameter portion is fixed to the core wire by gold-containing solder,
The medical guide wire according to any one of claims 1 to 4, wherein a length of the tip rigid portion of the gold-containing solder is 0.1 to 0.5 mm.   The medical guide wire according to claim 5, wherein the gold-containing solder penetrates into the inside of the coil in a range corresponding to 1 to 4 pitches from the tip in the small-diameter portion on the tip side of the coil spring. The inside of the coil spring is filled with resin, a resin layer made of the resin is formed on the outer periphery of the coil spring, and a hydrophilic resin layer is laminated on the surface of the resin layer,
The medical guide wire according to any one of claims 1 to 6, wherein a water-repellent resin layer is formed on a surface of the core wire.

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