JP5424248B2 - Medical guidewire - Google Patents

Description

  The present invention relates to a medical guide wire having a coil spring mounted on the outer periphery of a small-diameter portion on the distal end side of a core wire. More specifically, the coil spring has a high adhering strength to the core wire, and the shaping length in the shaping operation of the tip portion The present invention relates to a medical guide wire that can be made shorter than conventional ones, has high bending rigidity, and is excellent in torque transmission.

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.

  Here, as the solder for fixing the front end portion and the rear end portion of the coil spring to the core wire, Ag-Sn solder is used because of its low melting point and easy handling.

The solder that has penetrated into the coil contacts the outer peripheral surface of the core wire at the front end portion and the rear end portion of the coil spring, so that the coil spring is fixed to the core wire.
Further, the tip of the coil spring is formed by solder that has not penetrated into the coil.

  Therefore, in order to secure the fixing force of the coil spring to the core wire, it is necessary to sufficiently penetrate the solder into the coil at the tip of the coil spring fixed to the distal end of the core wire having the smallest outer diameter. is necessary. Specifically, it is necessary to allow the solder (Ag—Sn solder) to penetrate into the coil within a range corresponding to about 6 to about 8 pitches of the coil spring.

A rigid portion (including a tip formed of solder) formed by solder filled in the coil is formed at the tip of the guide wire thus manufactured.
The length of the tip rigid portion (the length corresponding to about 6 to about 8 pitches of the tip and coil) is about 0.8 to 1.1 mm.

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 a thinner wire diameter (0.010 inch) than the conventional one (wire 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, operability when accessing a microchannel in a CTO (chronic total occlusion) lesion is also good.

JP 2003-299739 A

  A further improvement in operability is required for a guide wire inserted through a microchannel in a CTO lesion. For example, it is desired to reduce frictional resistance during operation in a microchannel. However, the reduction in frictional resistance is limited only by reducing the wire diameter of the guide wire.

By the way, when the guide wire is inserted into the microchannel, the operator performs bending (shaping) of the distal end portion thereof.
For example, as shown in FIG. 5, when a rotational torque is applied on the proximal end side of the guide wire by bending a portion having a length of 1.0 mm from the tip of the guide wire G by 45 °, The distal end rotates on a circle having a diameter of about 1.4 mm.

This shaping operation greatly affects the operability of the guide wire in the microchannel.
From the viewpoint of reducing frictional resistance in the microchannel, it is preferable to reduce the rotation diameter (operation area) at the distal end of the guide wire. For this purpose, the shaping length (the bending length of the tip) is preferable. ) Should be as short as possible, specifically 0.7 mm or less.

However, in the conventional guide wire, since there is the above-mentioned rigid portion of the tip, the shaping length cannot be set to 1.0 mm or less, and this cannot sufficiently reduce the frictional resistance.
Note that if the length of the rigid portion of the tip is shortened by narrowing the range in which the solder (Ag—Sn solder) penetrates, the fixing force of the coil spring to the core wire cannot be secured, and the core wire and the coil spring cannot be secured. If a tensile force is applied between them, the core wire inserted into the coil spring is pulled out.

  On the other hand, a guide wire with a small diameter such as 0.010 inches does not have sufficient bending rigidity, so that the push-transmitting property at the time of insertion is inferior, and the guide wire is bent when the device is delivered after insertion. There is a problem that it is easy to deliver and inferior in delivery performance. In addition, the narrow guide wire is inferior in torque transmission.

The present invention has been made based on the above situation.
A first object of the present invention is to provide a medical guide wire in which the strength of fixing a coil spring to a core wire is high and the shaping length can be shortened as compared with the conventional one.
A second object of the present invention is to provide a medical guide wire excellent in operability in a microchannel of a CTO lesion.
The third object of the present invention is to provide a medical guide wire that is minimally invasive, has good operability when accessing a microchannel, has sufficient bending rigidity, and is excellent in torque transmission. There is to do.

The medical guide wire of the present invention is a core wire having a distal end side small diameter portion and a proximal end side large diameter portion having a larger outer diameter than the distal end side small diameter portion,
Attached to the outer periphery of the distal end side small diameter portion of the core wire along the axial direction, the tip side small diameter portion, the rear end side large diameter portion having a coil outer diameter larger than the tip side small diameter portion, and the tip side small diameter portion And a coil spring fixed to the core wire at least at the front end portion and the rear end portion, and a taper portion located between the rear end side large diameter portion,
The length of the small-diameter portion on the tip side of the coil spring is 5 to 100 mm, and the outer diameter of the coil is 0.012 inch (0.305 mm) or less.
The tip of the coil spring is fixed to the core wire with gold-containing solder made of Au-Ge solder, Au-Si solder, Au-In solder, or Au-Sb solder ,
The length of the tip rigid portion by the gold-containing solder is 0.1 to 0.5 mm.

Here, the “tip rigid portion” means the tip portion of a coil spring (guide wire) that can no longer be bent freely by the solder that has penetrated into the coil. When the tip is formed by solder, The tip is also a 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.

In the medical guide wire of the present invention, the following forms are preferable.
(1) The coil outer diameter of the small-diameter portion on the distal end side of the coil spring is 0.010 inch or less, particularly 0.006 to 0.010 inch.

(2) Both the outer diameter of the proximal end side large diameter portion of the core wire and the coil outer diameter of the rear end side large diameter portion of the coil spring are 0.014 inches or more.

(3) A range in which the coil pitch at the small diameter portion on the tip end side of the coil spring is 1.0 to 1.8 times the coil wire diameter, and the Au—Ge solder corresponds to 1 to 3 pitches of the coil spring. In the coil.

(4) The inside of the coil spring (a space surrounded by the outer periphery of the small-diameter portion on the distal end side of the core wire and the inner periphery of the coil spring) is filled with resin, and the outer periphery of the coil spring is filled with the resin A resin layer is formed, a hydrophilic resin layer is laminated on the surface of the resin layer, and a water-repellent resin layer is formed on the surface of the core wire.

(5) In the case of (4) above, the outer periphery including the tapered portion of the coil spring is covered with the resin layer and the hydrophilic resin layer, whereby a taper as a guide wire shape is formed. The taper angle is smaller than the taper angle of the taper portion of the coil spring.

(6) The coil spring includes a tip side densely wound portion having a coil pitch of 1.0 to 1.8 times the coil wire diameter, and a rear end side loosely wound coil having a coil pitch exceeding 1.8 times the coil wire diameter. It consists of parts.

(7) In the case of (6) above, the leading end side small-diameter portion and the tapered portion are formed by the leading end side closely wound portion of the coil spring, and the trailing end side large diameter portion is formed by the trailing end side loosely wound portion of the coil spring. That it is formed.

(8) The core wire is made of stainless steel.

According to the medical guide wire of the present invention, since the Au—Ge based solder is used as the solder for fixing the tip of the coil spring to the core wire, the length of the tip rigid portion is 0.1-0. Despite being as short as 5 mm (the solder fixing area is narrow), the coil spring fixing strength 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) Even if a tensile force is applied to the core wire inserted in the spring, 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.
In addition, treatment in a narrow region that cannot be performed using a conventional guide wire is also possible.

The medical guide wire of the present invention has a thin coil outer diameter at a small diameter portion of the tip side of 0.012 inches or less, a high fixing strength by Au—Ge solder, and a short tip rigid portion of 0.1 to 0.5 mm. The operability in the microchannel of the lesion is excellent.
The coil spring constituting the medical guide wire of the present invention has a rear end side large diameter portion whose coil outer diameter is larger than the distal end side small diameter portion, thereby ensuring bending rigidity and excellent torque transmission. Become.

  According to the medical guide wire of (4) above, since the resin is filled in the coil spring, the integrity of the core wire and the coil spring is remarkably improved. The operability can be further improved.

  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 (5) above, the guide wire is inserted by forming a taper having a smaller angle (smooth inclination) than the taper angle of the tapered portion of the coil spring as the shape of the guide wire. Can be performed more smoothly.

  According to the medical guide wire of the above (6) [(7)], good contrast (visibility) is expressed in the tip side densely wound portion (tip side small diameter portion and taper portion) of the coil spring. Can do.

It is the side view which fractured | ruptured one part which shows one 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 one 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, and (C) is a detailed view of part C. It is a side view which shows the state which shaped the front-end | tip part of the guide wire. It is explanatory drawing which shows typically the state which shaped the front-end | tip part of the guide wire.

The guide wire shown in FIG. 1 has 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 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 material of the core wire 10 is not particularly limited, and examples thereof include metals such as stainless steel (for example, SUS316, SUS304), gold, platinum, aluminum, tungsten, tantalum, and alloys thereof. Then, it is made of stainless steel.

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. 2, the total length (L ₁ ) of the guide wire is, for example, 1500 to 3000 mm, and 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 smaller than the inner diameter of the coil spring 20, the outer diameter of the proximal end side large-diameter portion 14 (D ₁₎ 1/5 It is preferably about ˜3 / 5.

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

  In the present embodiment, the front end side small diameter portion 21 and the taper portion 22 are formed from the front end side densely wound portion 201, and the rear end side large diameter portion 23 is formed from the rear end side loosely wound portion 202. The tip-side densely wound portion 201 (tip-side small diameter portion 21 and taper portion 22) 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. 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 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 end side small diameter portion 21 is 5 mm or more, the distal end side small diameter portion 21 can be inserted into most microchannels.
When the length (L ₂₁ ) of the distal end side small diameter portion 21 is 100 mm or less, it is possible to sufficiently secure the length of the rear end side large diameter portion 23 that contributes to improvement in bending rigidity and torque transmission.
The length (L ₂₂ ) of the tapered portion 22 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 23 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 20 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 22 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 distal end side small diameter portion 21 of the coil spring 20 is usually 0.012 inch (0.305 mm) or less, preferably 0.010 inch (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 end side small diameter portion 21 is 0.012 inch or less, the operability when accessing the microchannel (for example, lubricity in the microchannel) is excellent.

The outer diameter (D ₂₃ ) of the coil at the rear end side large diameter portion 23 of the coil spring 20 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 23 is 0.014 inch or more, sufficient bending rigidity (push transmission at the time of insertion / delivery performance of the device after the insertion) is obtained for the guide wire. In addition, the guide wire (the guide wire of the present embodiment) is excellent in torque transmission.
The ratio of the outer diameter of the coil (D ₂₃ / D ₂₁ ) between the rear end side large diameter portion 23 and the front end side small diameter portion 21 is preferably 1.1 to 2.3. .4.

Although the outer 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 is 60 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. ).

  In the guide wire of the present embodiment, the distal end side small diameter portion 21, the tapered portion 22 and the rear end side large diameter portion 23 of the coil spring 20 are 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 FIG. 1 and FIG. 3A, the distal end portion of the distal end side small diameter portion 21 that is the distal end portion of the coil spring 20 is fixed to the core wire 10 with Au—Ge solder 31.
That is, the Au—Ge-based solder 31 penetrates into the tip portion of the coil spring 20 (tip portion of the tip side small diameter portion 21) and comes into contact with the outer periphery of the core wire 10 (distal end side small diameter portion 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—Ge solder 31 penetrates into the coil in a range corresponding to approximately two pitches of the coil spring 20.
In addition, a substantially hemispherical tip is formed by the Au—Ge 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 of the present embodiment has a hardened tip portion of the Au—Ge solder 31 [the coil spring 20 (which can no longer be bent freely by the Au—Ge 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—Ge 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—Ge 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 end side small diameter portion 21 of the coil spring is 1.0 to 1.8 of the coil wire diameter so that the length of the distal rigid portion is 0.1 to 0.5 mm. It is preferable that the Au-Ge solder penetrates into the coil within a range corresponding to 1 to 3 pitches of the coil spring.

  The medical guide wire according to the present invention is characterized in that an Au—Ge solder is used as a solder for fixing the small diameter portion of the coil spring to the core wire.

By fixing the stainless steel and platinum (alloy) using an Au-Ge solder, an adhesive force (tensile strength) about 2.5 times that obtained when fixing with an Ag-Sn solder is obtained. 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 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—Ge solder is superior in contrast to Ag—Sn solder.
Further, the Au—Ge solder has better corrosion resistance against blood and body fluid than the Ag—Sn solder.

As shown in FIGS. 1 and 3B, the rear end portion of the tapered portion 22 that is an intermediate portion of the coil spring 20 is fixed to the core wire 10 with an Au—Ge solder 32.
That is, the Au—Ge-based solder 32 penetrates into the rear end portion of the taper portion 22 and comes into contact with the outer periphery of the core wire 10 (distal end side small diameter portion 11), whereby the rear end portion of the taper portion 22 is It is fixed to the core wire 10 (distal end side small diameter portion 11).

As shown in FIGS. 1 and 3C, the rear end portion of the rear end side large diameter portion 23, which is the rear end portion of the coil spring 20, 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 of the coil spring 20 (the rear end portion of the rear end side large diameter portion 23), 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 23 of the coil spring 20 is fixed is the portion (distal end) to which the tip side small diameter portion 21 of the coil spring 20 is fixed. Therefore, it is possible to use an Ag—Sn solder having a smaller fixing force than that of the Au—Ge 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 14 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.

The outer periphery of the tapered portion 22 of the coil spring 20 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. 2) from the tip of the taper portion 22, and the end point of the taper is the proximal end from the rear end of the taper portion 22. On the side (position indicated by T ₂ in FIG. 2). That is, the taper as the shape of the guide wire has a taper angle smaller than the taper angle of the taper portion 22 and a taper length (L ₅ ) longer than the taper portion 22 length (L ₂₂ ). ing.

Thus, by covering the taper portion 22 with the resin, the taper shape as the guide wire is made gentler than the taper of the taper portion 22, so that the guide wire can be inserted more smoothly.
2, the length of the tapered portion 22 (L _22), for example when it is about 1.5 mm, it is preferable that the length of the taper of the guidewire (L ₅₎ of about 5 to 6 mm.

According to the guide wire of the present embodiment, since the Au—Ge solder is used as the solder for fixing the distal end portion of the coil spring 20 (the distal end portion of the distal-side small diameter portion 21) 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 strength of fixing the coil spring to the core wire (distal end side small diameter portion 11) is sufficiently high, and the coil spring 20 and the core wire 10 are 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 21 at the tip end side of the coil spring 20 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 23 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 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.

  Further, since the coil spring 20 includes a front end side closely wound portion 201 constituting the front end side small diameter portion 21 and the taper portion 22, and a rear end side loosely wound portion 202 constituting the rear end side large diameter portion 23, the front end side Good contrast (visibility) can be developed in the distal-side small-diameter portion 21 and the tapered portion 22 that are formed by the side densely wound portion 201.

FIG. 4A shows a state where the distal end portion of the guide wire of the present invention in which the outer diameter of the coil on the distal end side small diameter portion is 0.010 inch is shaped. The length of the rigid portion of the guide wire is 0.35 mm (the penetration range of the Au—Ge solder corresponds to two pitches of the coil spring), and the shaping length is 0.32 mm on the inner side length (L ₅₁ ). The outer length (L ₅₂ ) is 0.53 mm.
FIG. 4B shows a state where the distal end portion of a conventional guide wire in which the coil spring has a coil outer diameter of 0.010 inch is shaped. The length of the rigid portion of the guide wire is 0.8 mm (the penetration range of the Ag—Sn solder is equivalent to 6 pitches of the coil spring), and the shaping length is 0.82 mm on the inner length (L ₅₁ ). The outer length (L ₅₂ ) is 1.01 mm.

As described above, the embodiment in which the Au—Ge solder is used as the solder for fixing the tip part (tip part of the tip side small diameter part) and the middle part (back end part of the taper part) of the coil spring to the core wire has been described. However, in place of the Au—Ge solder, the same effect as when the Au—Ge solder is used can be obtained by using another gold-containing solder.
Examples of the gold-containing solder other than the Au—Ge solder include Au alloy solder such as Au—Si solder, Au—In solder, Au—Sb solder, and Au solder.

<Example 1>
(1) Preparation of guide wire:
A coil spring is attached to the small diameter part of the distal end of the core wire (core wire made of stainless steel coated with PTFE) whose outer diameter of the proximal end side large diameter part is 0.014 inch, and is shown in FIGS. Six guide wires of the present invention having the above-described structure were produced.

Here, the coil spring 20 has a front end side small-diameter portion 21 and a tapered portion 22 formed by a front end side closely wound portion 201 (coil pitch is about 1.3 times the coil wire diameter), and a rear end side loosely wound portion 202 ( The rear end side large diameter portion 23 is formed by a coil pitch of about 3.0 times the coil wire diameter), the length (L ₂ ) is 165 mm, and the coil outer diameter (D ₂₁ ) at the front end side small diameter portion 21 is 0.010 inch, length (L ₂₁ ) is 38.5 mm, coil outer diameter (D ₂₃ ) at the rear end side large diameter portion 23 is 0.014 inch, length (L ₂₃ ) is 125 mm, taper portion 22 A length (L ₂₂ ) of 1.5 mm was used.
In addition, the tip portion of the coil spring 20 (tip portion of the tip-side small diameter portion 21) and the middle portion (back end portion of the taper portion 22) are secured to the core wire using Au—Ge solder, The end portion (the rear end portion of the rear end side large diameter portion 23) was fixed to the core wire 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 any one of 1 to 3. 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.

(2) Guidewire evaluation:
The minimum shaping length (minimum bendable length) was measured for each of the six guide wires obtained by the above (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.

<Comparative Example 1>
Six guide wires for comparison were made using Ag—Sn solder as solder for fixing the tip, middle and rear ends of the coil spring to the core wire.
In each of the six guide wires, the coil pitch number (abbreviated as “pitch number” in Table 2) corresponding to the region (length) in which the solder has penetrated inside the coil is any one of 1 to 3. I did it. Table 2 shows the length of the rigid portion of the tip.
Further, after the coil spring is attached to the core wire, in the same manner as in Example 1, the inside of the coil spring is filled with a cured resin, and a resin layer made of a cured resin is formed on the outer periphery of the coil spring. A hydrophilic resin layer was laminated.
For each of the six guide wires obtained as described above, the minimum shaping length was measured in the same manner as in Example 1 to evaluate the sticking property. The results are also shown in Table 2 below.
The comparative example 1 is a comparative example in which no Au—Ge solder was used when fixing the tip of the coil spring to the core wire.

<Comparative Examples 2-6>
As a solder for fixing the tip, middle and rear ends of the coil spring to the core wire, Ag-Sn solder is used, and a comparative guide wire having a tip rigid portion exceeding 0.5 mm is used. Produced.
In each of the guide wires, the pitch number of the coil (abbreviated as “pitch number” in Table 3) corresponding to the region (length) in which the solder penetrated into the coil was set to any one of 4 to 8. . Table 3 shows the length of the tip rigid portion.
Further, after the coil spring is attached to the core wire, in the same manner as in Example 1, the inside of the coil spring is filled with a cured resin, and a resin layer made of a cured resin is formed on the outer periphery of the coil spring. A hydrophilic resin layer was laminated.
For each of the guide wires obtained as described above, the minimum shaping length was measured in the same manner as in Example 1. The results are also shown in Table 3 below.

<Examples 2 to 4>
As the solder for fixing the tip and middle portions of the coil spring to the core wire, any one of Au-Si solder, Au-In solder, and Au-Sb solder is used, and the rear end of the coil spring is used as the core wire. Nine guide wires of the present invention (three in each example) were produced by using Ag—Sn solder as the solder for fixing to the substrate. In each of the obtained guide wires, the number of coil pitches (abbreviated as “pitch number” in Table 4) corresponding to the region (length) in which the solder has penetrated inside the coil is any one of 1 to 3. I did it. Table 4 shows the length of the rigid portion of the tip.
Further, after the coil spring is attached to the core wire, in the same manner as in Example 1, the inside of the coil spring is filled with a cured resin, and a resin layer made of a cured resin is formed on the outer periphery of the coil spring. A hydrophilic resin layer was laminated.
For each of the nine guide wires obtained as described above, the minimum shaping length was measured in the same manner as in Example 1, and the sticking property was evaluated. The results are also shown in Table 4 below.

DESCRIPTION OF SYMBOLS 10 Core wire 11 Distal end side small diameter part 13 Tapered part 14 Proximal end side large diameter part 20 Coil spring 21 Front end side small diameter part 22 Tapered part 23 Back end side large diameter part 201 Front end side close winding part 202 Back end side loose winding Portion 31 Au-Ge solder 32 Au-Ge solder 33 Ag-Sn solder 40 Cured resin 40A Resin layer 50 Hydrophilic resin layer

Claims (1)

A core wire having a distal end side small diameter portion and a proximal end side large diameter portion having an outer diameter larger than that of the distal end side small diameter portion;
Attached to the outer periphery of the distal end side small diameter portion of the core wire along the axial direction, the tip side small diameter portion, the rear end side large diameter portion having a coil outer diameter larger than the tip side small diameter portion, and the tip side small diameter portion And a coil spring fixed to the core wire at least at the front end portion and the rear end portion, and a taper portion located between the rear end side large diameter portion,
The length of the small-diameter portion on the tip side of the coil spring is 5 to 100 mm, and the outer diameter of the coil is 0.012 inch (0.305 mm) or less.
The tip of the coil spring is fixed to the core wire with gold-containing solder made of Au-Ge solder, Au-Si solder, Au-In solder, or Au-Sb solder ,
A medical guide wire characterized in that the length of the tip rigid portion made of gold-containing solder is 0.1 to 0.5 mm.

Images