WO2013145893A1

WO2013145893A1 - Medical guide wire

Info

Publication number: WO2013145893A1
Application number: PCT/JP2013/053077
Authority: WO
Inventors: 亮一奥村; 浩範河崎
Original assignee: 日本ライフライン株式会社
Priority date: 2012-03-29
Filing date: 2013-02-08
Publication date: 2013-10-03
Also published as: CN104023783B; HK1200746A1; TWI517869B; TW201350154A; CN104023783A; KR20140141605A; JP2013202308A; JP5404840B2; KR101844630B1

Abstract

A medical guide wire has: a core wire (10) having a distal end small-diameter section (11) and a proximal end large-diameter section (14); and a coiled spring (20) mounted to the outer periphery of the distal end small-diameter section (11). The coiled spring (20) comprises: a front end closely wound section (21) having a pitch which is 1.0 to 1.8 times the diameter of the coil wire; and a rear end loosely wound section (22) having a pitch which is 1.8 to 2.5 times the diameter of the coil wire. The inside of the rear end loosely wound section (22) is filled with a resin (40), and a resin layer (40A) consisting of the resin is formed on the outer periphery of the rear end loosely wound section (22). A hydrophilic resin coating layer (50) is laminated and formed on the surface of the resin layer (40A). The outer periphery of the front end closely wound section (21) is not coated with a resin, and a material which forms the coiled spring (20) is exposed at the outer periphery. The guide wire has satisfactory lubricating properties at the distal end thereof, has satisfactory insertability, enables information within a blood vessel to be sufficiently sensed as resistance (change) by the operator's hand, and can be reliably advanced to a destination site.

Description

Medical guidewire

The present invention relates to a medical guide wire having a coil spring 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 requires flexibility and 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 Patent Document 1).

In addition, the inside of the coil spring attached to the distal end portion of the core wire is filled with resin, and a resin layer made of the resin is formed on the outer periphery of the coil spring, and a hydrophilic resin layer is formed on the surface of the resin layer. A laminated guide wire is introduced (see Patent Document 2). By forming the hydrophilic resin layer on the outer periphery of the coil spring, lubricity is imparted to the distal end portion of the guide wire, and the insertion property of the guide wire can be improved.

JP 2003-299739 A JP 2010-214054 A

For information in the blood vessel in which the guide wire is inserted (for example, the status of a lesion site such as a stenosis or an occlusion), the operator can change the resistance (change) of the blood vessel site with which the distal end of the guide wire is in contact. Is grasped by feeling at hand.

However, in the guide wire in which the hydrophilic resin layer is formed on the outer periphery of the coil spring as in the guide wire described in Patent Document 2, such resistance (change) can hardly be felt. This makes it difficult to grasp information.
In addition, such a guide wire can obtain good lubricity, but its distal end portion is easy to slip, so that it is difficult to push it toward the target site.
Furthermore, since the resistance (change) can hardly be felt, a tip load is applied more than necessary, and the blood vessel may be damaged.

On the other hand, for example, when a guide wire is inserted into a microchannel in a CTO lesion, an operator performs bending and shaping of the distal end portion (shaping).

However, in the guide wire in which the resin is filled in the coil spring like the guide wire described in Patent Document 2, the shaping operation is difficult to be performed by the resin filled in the tip portion.

The present invention has been made based on the above situation.
The object of the present invention is to have a good lubricity at the distal end and a good guide wire insertion property, but it is possible to sufficiently grasp information in the blood vessel as resistance (change) on the hand side. ,
An object of the present invention is to provide a medical guide wire that can be reliably pushed toward a target site.
Another object of the present invention is to provide a medical guide wire that can easily perform a shaping operation.

(1) The medical guidewire of the present invention includes 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;
A medical guide wire having a coil spring attached to the outer periphery of the small-diameter portion on the distal end side of the core wire along the axial direction, and having a coil spring fixed to the core wire at least at the front end portion and the rear end portion;
The coil spring includes a close winding portion on the front end side having a coil pitch of 1.0 to 1.8 times the coil wire diameter, and a sparse winding on the rear end side having a coil pitch of 1.8 to 2.5 times the coil wire diameter. Consisting of winding parts,
The inside of the rear end side loosely wound portion is filled with resin, a resin layer made of the resin is formed on the outer periphery of the rear end side loosely wound portion, and a hydrophilic resin coating layer is laminated on the surface of the resin layer Formed,
The outer periphery of the tip side densely wound portion is not covered with resin, and the constituent material (metal) of the coil spring is exposed.

According to the medical guide wire having such a configuration, the outer periphery of the distal-side densely wound portion is not covered with the resin, and the constituent material of the coil spring is exposed, so that the blood vessel into which the guide wire is inserted The information inside can be fully grasped as resistance (change) on the hand side (excellent in information transmission).
In addition, it is possible to sufficiently grasp the information on the blood vessel part in contact with the distal side tightly wound part, and the distal side closely wound part is difficult to slip, so that the medical guide of the present invention is directed toward the target part in the blood vessel. The wire can be pushed forward reliably (excellent guide wire direction selectivity).

In addition, since the inside of the rear end side loosely wound portion is filled with resin, the core wire and the coil spring (rear end side loosely wound portion) can be integrated, and the torque transmission and operability of the guide wire can be integrated. Can be improved (excellent torque transmission).
In addition, a resin layer is formed on the outer periphery of the rear end side loosely wound portion, and a hydrophilic resin coating layer is laminated on the surface of the resin layer, thereby filling the inside of the rear end side loosely wound portion. Since the hydrophilic resin coating layer is laminated on the outer periphery of the rear end side loosely wound portion through the resin layer made of the same resin as the one, the hydrophilic resin coating layer is securely fixed, and the hydrophilic resin is preferably used. Lubricity can be stably expressed (excellent adhesion of the hydrophilic resin coating layer to the outer periphery of the rear end side loosely wound portion).

(2) In the medical guidewire of the present invention, it is preferable that the distal end side closely wound portion is not filled with resin.
According to such a configuration, it is possible to sufficiently ensure flexibility and flexibility in the front end side closely wound portion, and it is possible to easily perform a shaping operation in the coil spring (front end side closely wound portion).

(3) In the medical guidewire of the present invention, an outer diameter (D ₁ ) of the proximal end side large diameter portion of the core wire and a coil outer diameter (D ₂ ) of the coil spring are 0.012 inches or less,
The coil spring length (L ₂ ) is 51 to 800 mm,
The length (L ₂₁ ) of the tip side densely wound portion is 1 to 50 mm,
It is preferable that the length (L ₂₂ ) of the rear end side loosely wound portion is 50 to 750 mm.

(4) In the medical guide wire of the present invention, it is preferable that an intermediate portion including the front end side closely wound portion and the rear end side loosely wound portion of the coil spring is fixed to the core wire by solder.
(5) In the medical guidewire according to (4), it is preferable that a tip portion and an intermediate portion of the coil spring are fixed to the core wire with gold-containing solder.
(6) In the medical guidewire of the present invention, it is preferable that the core wire is made of stainless steel.

According to the medical guidewire of the present invention, it has good lubricity at the distal end, and has good insertability, while sufficiently grasping information in the blood vessel as resistance (change) on the hand side. Can be pushed forward toward the target site.
Further, since the resin is filled in the rear end side loosely wound portion, the torque transmission is excellent.
In addition, according to the medical guide wire of the present invention including the distal end side tightly wound portion that is not filled with resin, the shaping operation can be further easily performed.

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.

A guide wire 1 shown in FIGS. 1 and 2 includes a core wire 10 having a distal end side small diameter portion 11 and a proximal end side large diameter portion 14 having a larger outer diameter than the distal end side small diameter portion 11, and the core wire 10. A medical guide wire having a coil spring 20 attached to the outer periphery of the distal end side small-diameter portion 11 along the axial direction and fixed to the core wire 10 at the front end portion, the intermediate portion, and the rear end portion, The coil spring 20 includes a front end side closely wound portion 21 having a coil pitch of 1.0 to 1.8 times the coil wire diameter, and a rear end side having a coil pitch of 1.8 to 2.5 times the coil wire diameter. The rear end side loosely wound portion 22 is filled with the cured resin 40, and a resin layer 40A made of the cured resin is formed on the outer periphery of the rear end side loosely wound portion 22 to form the resin. Hydrophilic resin coating layer 50 on the surface of layer 40A On the other hand, the outer periphery of the tip side densely wound portion 21 is not covered with resin, and the constituent material of the coil spring 20 is exposed, and the inside of the tip side closely wound portion 21 is also filled with resin. Not a guide wire.

The guide wire 1 of the present embodiment 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.

The total length (L ₁ ) of the guide wire 1 shown in FIG. 2 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 a preferred example is 0.010 inch.

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 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 About 3/5.

The coil spring 20 constituting the guide wire 1 of the present embodiment is mounted on 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 is formed of a single wire, and has a closely wound end 21 with a coil pitch of 1.0 to 1.8 times the coil wire diameter, and a coil pitch of 1.8 to 2 of the coil wire diameter. The rear end side sparsely wound portion 22 which is .5 times larger, and the tip side densely wound portion 21 and a tip which will be described later constitute an X-ray opaque region.

The coil pitch in the front end side densely wound portion 21 is 1.0 to 1.8 times the coil wire diameter, and is 1.0 times as a suitable example.
The coil pitch in the rear end side loosely wound portion 22 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 21.
When the pitch is the same throughout the coil spring 20, the X-ray non-transparent region becomes long, and the visibility is lowered.

The coil outer diameter (D ₂ ) 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 0.006 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 20 is also 0.012 inch or less, The operability when accessing the microchannel (for example, lubricity in the microchannel) is excellent.
The outer diameter of the wire constituting the coil spring 20 is not particularly limited, but is preferably 30 to 90 μm, and 60 μm is a preferable example.

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

In the guide wire 1 of the present embodiment, the front end portion, the rear end portion, and the intermediate portion of the coil spring 20 (boundary portions of the front end side densely wound portion 21 and the rear end side loosely wound portion 22) are soldered 31 and 32, respectively. 33 is fixed to the outer periphery of the distal end side small diameter portion 11 of the core wire 10.

As shown in FIG. 1, the tip of the coil spring 20 is fixed to the core wire 10 with solder 31. That is, the solder 31 penetrates into the coil spring 20, and the 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 20 is fixed to the core wire 10. Yes.
In addition, a substantially hemispherical tip is formed by 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 is provided with a rigid end portion by the solder 31 (the distal end portion of the coil spring 20 that can no longer be freely bent by the solder 31 that has penetrated into the coil, and the distal end formed by the solder 31. A rigid part) is formed.

Further, an intermediate portion including a boundary region between the front end side densely wound portion 21 and the rear end side loosely wound portion 22 of the coil spring 20 is fixed to the core wire 10 by the solder 32. That is, the solder 32 penetrates into the coil spring 20, and the solder 32 comes into contact with the outer periphery of the core wire 10 (distal end side small diameter portion 11), whereby the intermediate portion of the coil spring 20 is fixed to the core wire 10. Yes.

Furthermore, the rear end portion of the coil spring 20 is fixed to the core wire 10 with solder 33. That is, the solder 33 penetrates into the coil spring 20, and the solder 33 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 coil spring 20 is fixed to the core wire 10. ing.

It is preferable to use gold-containing solder as the

solders

31 and 32 for fixing the tip part and the intermediate part of the coil spring 20 to the core wire 10 respectively.
By using gold-containing solder as the solder 31.32, the fixing strength of the coil spring 20 to the core wire 10 can be made sufficiently high (higher than the breaking strength of the small diameter portion 11 on the distal end side of the core wire 10). Even when a tensile force is applied to the core wire 10 inserted in the coil spring 20, the core wire 10 is not pulled out. 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.
On the other hand, examples of the solder 33 for fixing the rear end portion of the coil spring 20 to the core wire 10 include silver-based solder such as Ag—Sn.

As shown in FIG. 1, in the guide wire 1 according to the present embodiment, the inside of the rear end side loosely wound portion 22 of the coil spring 20 is filled with the cured resin 40 and the outer periphery of the rear end side loosely wound portion 22. Further, a resin layer 40A (cured resin layer covering the coil wire) is formed by the cured resin 40, and a hydrophilic resin coating layer 50 is laminated on the surface of the resin layer 40A.

By filling the inside of the rear end side sparsely wound portion 22 of the coil spring 20 with the cured resin 40, the core wire 10 and the coil spring 20 are integrated, and the torque transmission performance of the guide wire is greatly improved. The rotational torque transmitted from the 10 proximal end large diameter portions 14 is reliably transmitted to the distal end of the coil spring 20 integrated with the distal end small diameter portion 11.

Further, a resin layer 40A is formed on the outer periphery of the rear end side loosely wound portion 22 of the coil spring 20, and a hydrophilic resin coating layer 50 is laminated on the surface of the resin layer 40A (rear end side loosely wound portion). 2
2), the hydrophilic resin coating layer 50 is formed on the outer periphery of the coil spring 20 via the resin layer 40A. Therefore, the hydrophilic resin coating layer 50 is firmly fixed to the coil spring 20, thereby The suitable lubricity due to can be expressed stably.

Here, the inside of the rear end side sparsely wound portion 22 is filled, and the cured resin 40 constituting the resin layer 40A has a good adhesiveness to both the coil spring 20 and the hydrophilic resin. Specific examples thereof include a photo-curing resin such as urethane acrylate resin, polyurethane resin, silicone resin, epoxy resin, acrylic resin, and nylon resin, or a cured product of thermosetting resin.
The film thickness of the resin layer 40A covering the outer periphery of the rear end side loosely wound portion 22 is, for example, 1 to 100 μm, preferably 3 to 10 μm.

As the hydrophilic resin that constitutes the hydrophilic resin coating layer 50 that is laminated on the surface of the resin layer 40A, all conventionally known hydrophilic polymers that are used for hydrophilic treatment of medical devices can be used. Specifically, polysaccharides such as polyethylene glycol, polyethylene oxide, polyol, polyacrylamide, polyvinyl pyrrolidone, polyvinyl alcohol, polyether, polyurethane, polycarboxylic acid and derivatives thereof, cellulose, protein, hyaluronic acid can be exemplified. . Moreover, these hydrophilic polymers may have a crosslinked structure.
The thickness of the hydrophilic resin layer 50 is, for example, 1 to 30 μm, preferably 3 to 19 μm.

The method of filling the cured resin 40 and forming the resin layer 40A and the method of forming the laminated layer of the hydrophilic resin 50 are not particularly limited. For example, the rear end side loosely wound portion attached to the core wire 10 is used. 22 is immersed in a curable resin to fill the inside of the rear end side loosely wound portion 22 with a curable resin, and a resin layer is formed on the surface of the rear end side loosely wound portion 22, which is thermoset. Alternatively, a method may be mentioned in which a cured resin 40 (resin layer 40A) is obtained by photocuring, and then a hydrophilic resin is applied to the surface of the resin layer 40A by an appropriate means.
Here, in the case where the tip side densely wound part 21 is immersed in the curable resin together with the rear end side loosely wound part 22, the outer periphery of the tip side densely wound part 21 is masked, etc. It is preferable to prevent inflow and adhesion of the curable resin to the inside or the outer periphery.

As shown in FIG. 1, in the guide wire 1 of the present embodiment, the outer periphery of the tip side densely wound portion 21 of the coil spring 20 is not covered with resin, and the constituent material of the coil spring 20 (X-ray opaque substance) Etc.) are exposed.
Thereby, information in the blood vessel into which the guide wire 1 of the present embodiment is inserted (for example, the state of a lesion site such as a stenosis part or an obstruction part) can be sufficiently grasped as resistance (change) on the hand side. .
In addition, it is possible to sufficiently grasp the information on the blood vessel part that is in contact with the distal side densely wound portion 21, and the distal side closely wound portion 21 that is not covered with the hydrophilic resin is difficult to slip. The guide wire 1 of the present embodiment can be reliably pushed toward the site.

Moreover, in the guide wire 1 of this embodiment, the inside of the front end side tightly wound portion 21 is not filled with resin. Thereby, the flexibility and softness in the front end side densely wound portion 21 can be sufficiently secured, and the shaping operation can be easily performed in the front end side closely wound portion 21.
In addition, even if the inside of the front end side densely wound portion 21 is not filled with resin, the torque transmission property of the guide wire 1 is improved by filling the inside of the rear end side loosely wound portion 22 with the cured resin 40. Sufficiently secured.

The length (L ₂ ) of the coil spring 20 shown in FIG. 2 is preferably 51 to 800 mm, more preferably 85 to 310 mm, and 115 mm if a suitable example is shown.
The length (L ₂₁ ) of the tip side densely wound portion 21 is preferably 1 to 50 mm, more preferably 20 to 40 mm, and 30 mm if a suitable example is shown.
The length (L ₂₂ ) of the rear end side loosely wound portion 22 is preferably 50 to 750 mm, more preferably 65 to 270 mm, and 85 mm if a suitable example is shown.

If the length (L ₂₁ ) of the distal end side tightly wound portion 21 that is not coated with resin is too small, information in the blood vessel into which the guide wire is inserted cannot be sufficiently grasped, and the guide The distal end of the wire becomes slippery and it is difficult to push such a guidewire toward the target site.
On the other hand, when the length (L ₂₁ ) of the distal end side tightly wound portion 21 is excessive, the lubricity at the distal end portion of the guide wire is insufficient and, for example, it is difficult to pass through the stenosis site. For example, the insertion property of the guide wire is impaired.

Further, when the length (L ₂₂ ) of the rear end side loosely wound portion 22 is too small, the lubricity of the distal end portion of the guide wire is insufficient and the guide wire insertion property is impaired. Further, the torque transmission performance of the guide wire may be impaired.
On the other hand, when the length (L ₂₁ ) of the leading end side densely wound portion 21 becomes relatively small due to the excessive length (L ₂₂ ) of the rear end side loosely wound portion 22, the guide wire is Information in the inserted blood vessel cannot be fully grasped, and it is difficult to push the guide wire toward the target site.

The length (L ₃ ) of the substantially hemispherical tip formed by the solder 31 is, for example, 0.1 to 5.0 mm, and 0.3 mm is a preferable example.

As described above, according to the guide wire 1 of the present embodiment, the distal end portion to which the coil spring 20 (rear end side loosely wound portion 22) is attached has good lubricity and enters the blood vessel. While the insertability of the coil spring 20 is good, the outer periphery of the distal end side densely wound portion 21 is not covered with resin, and the constituent material (metal) of the coil spring 20 is exposed, so that the information in the blood vessel is resisted (changed). ) Can be grasped sufficiently on the hand side, and can be reliably pushed toward the target site.
Further, since the cured resin 40 is filled in the rear end side loosely wound portion 22, the torque transmission is excellent.
In addition, since the inside of the distal end side tightly wound portion 21 is not filled with resin, the shaping operation can be easily performed.

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 close winding part 22 Back end side loose winding part 31 Solder 32 Solder 33 Solder 40 Curing resin 40A Resin layer 50 Hydrophilic Resin layer

Claims

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;
A medical guide wire having a coil spring attached to the outer periphery of the small-diameter portion on the distal end side of the core wire along the axial direction, and having a coil spring fixed to the core wire at least at the front end portion and the rear end portion;
The coil spring includes a close winding portion on the front end side having a coil pitch of 1.0 to 1.8 times the coil wire diameter, and a sparse winding on the rear end side having a coil pitch of 1.8 to 2.5 times the coil wire diameter. Consisting of winding parts,
The inside of the rear end side loosely wound portion is filled with resin, a resin layer made of the resin is formed on the outer periphery of the rear end side loosely wound portion, and a hydrophilic resin coating layer is laminated on the surface of the resin layer Formed,
The medical guide wire according to claim 1, wherein the outer peripheral portion of the distal-end side densely wound portion is not covered with resin, and the constituent material of the coil spring is exposed.
2. The medical guide wire according to claim 1, wherein the distal end side tightly wound portion is not filled with resin.
The outer diameter (D 1 ) of the large diameter portion on the proximal end side of the core wire and the coil outer diameter (D 2 ) of the coil spring are 0.012 inches or less,
The coil spring length (L 2 ) is 51 to 800 mm,
The length (L 21 ) of the tip side densely wound portion is 1 to 50 mm,
3. The medical guide wire according to claim 1, wherein a length (L 22 ) of the rear end side loosely wound portion is 50 to 750 mm.
The medical device according to any one of claims 1 to 3, wherein an intermediate portion including a front end side closely wound portion and a rear end side loosely wound portion of the coil spring is fixed to the core wire by solder. Guide wire.
The medical guide wire according to claim 4, wherein a tip portion and an intermediate portion of the coil spring are fixed to the core wire by a gold-containing solder.
The medical guide wire according to any one of claims 1 to 5, wherein the core wire is made of stainless steel.