JP2623066C - - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guide wire used for introducing a catheter to a necessary part of a human body for treatment or examination. 2. Description of the Related Art In recent years, catheters have been introduced into blood vessels for examination and treatment of heart diseases and the like. When introducing such a catheter into a target site in the body, a guide wire is inserted into the catheter, the distal end of the guide wire is slightly projected from the distal end of the catheter, and the catheter is guided to the target site by the guide wire. . As such a guide wire for a catheter, for example, JP-A-60-7862
And JP-A-60-63066. These guide wires have an inner core formed by a superelastic metal body at least at the distal end, and the entire inner core is coated with a synthetic resin. This guide wire has excellent flexibility and a restoring property at the distal end, so that it is excellent in guiding the catheter. The above-mentioned guide wire has an extremely excellent effect in terms of catheter guideability. However, in the above-described guide wire, a metal wire such as a coil is not coated on the inner core unlike a conventional guide wire, and the inner core is merely coated with a synthetic resin. Although it is conceivable to include an X-ray contrast material in the coated synthetic resin, its content is limited due to a decrease in physical properties of the synthetic resin film, and the overall X-ray contrast function is not very high. Was. In particular, the inner core formed of a metal body has a problem that the X-ray contrast at the tip is particularly poor because the tip is thinner. Recently, it has been considered to introduce a catheter into a thinner blood vessel, for example, a blood vessel such as an inner blood vessel of a brain or a blood vessel constituting a kidney. Is required. For this reason, in the case of a guide wire in which the inner core is coated with a synthetic resin, it is expected that the X-ray contrast at the distal end portion will be further reduced, and it will be difficult to introduce the catheter into the target site. Therefore, the present invention provides a guide wire for a catheter in which even when the guide wire is formed into a thinner guide wire, the distal end thereof has a high X-ray contrast function, and the operation of introducing the catheter into a target site can be easily performed. Is provided. Means for solving the problems are achieved by an inner core integrally formed with a rigid main body, a thinner tip having a smaller diameter than the main body, and a lower rigidity. Enclose the outer peripheral surface of the tip of the core,
And a high X-ray contrast part made of a metal having high X-ray contrast fixed to the tip of the inner core, and the high X-ray contrast part being in close contact with the entire inner core to which the high X-ray contrast part is fixed and the entire inner core And a guide wire having a lubricating substance having lubricity when wetted on the surface. And it is preferable that the said annular member is a coil or a pipe-shaped member.
Further, it is preferable that the inner core is formed of a superelastic metal. Also,
Preferably, the coiled high X-ray contrast material is formed of any one of gold, platinum, lead, silver, bismuth, and tungsten. Further, the distal end of the inner core may be formed so as to gradually decrease in diameter toward the distal end. Further, the high X
The length of the line contrast part may be 1 to 10 mm. The inner core is formed integrally from, for example, a TiNi alloy. An embodiment of the guide wire of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of one embodiment of the guide wire of the present invention. The guide wire 1 according to the present invention is provided at an end of the inner core 2 in which a main body 2 a having high rigidity, a distal end 2 b having a smaller diameter than the main body 2 a and having low rigidity are integrally formed, and a distal end of the inner core 2. And a synthetic resin film 4 enclosing the whole of the inner core 2 provided with the high X-ray contrast portion 3 and the lubricating substance fixed on the surface of the synthetic resin film. . An embodiment of the guide wire of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of one embodiment of the guide wire of the present invention, and FIG. 2 is an enlarged cross-sectional view taken along line II of FIG. The guide wire 1 according to the present invention is provided at an end of the inner core 2 in which a main body 2 a having high rigidity, a distal end 2 b having a smaller diameter than the main body 2 a and having low rigidity are integrally formed, and a distal end of the inner core 2. And a synthetic resin film 4 having a substantially uniform outer diameter and enclosing the entire inner core 2 provided with the high X-ray contrast part 3. Therefore, the guide wire of the present invention will be described with reference to FIGS. The inner core 2 of the guide wire 1 has a main body 2a and a tip 2b, and is integrally formed of a superelastic metal. The distal end portion 2b is formed so as to gradually decrease in diameter from the distal end of the main body portion 2a toward the distal end. By having such a small diameter, the rigidity is lower than that of the main body. As described above, by gradually reducing the diameter of the distal end of the inner core, when force is applied to the distal end, the distal end is gradually bent, thereby improving operability. As the inner core 2, a TiNi alloy of 49 to 53 atomic% Ni, 38.5 to 41.5
1 wt% X Cu-Zn-X alloy (X = B
e, Si, Sn, Al, Ga), and a superelastic metal body such as a 36-38 atomic% Al Ni-Al alloy is preferably used. Particularly preferred is the above-mentioned TiNi alloy. The outer diameter of the main body 2a of the inner core 2 is 0.10 to 1.00 mm, more preferably 0.15 to 0.40 mm, and the length is 1000 to 4000 mm, more preferably 1500 to 3000 mm. Buckling strength (yield stress under load) is 30 to 1
00 Kg / mm ² (22 ° C.), more preferably 40 to 55 Kg / mm ² , and the restoring stress (yield stress at the time of unloading) is 20 to 80 Kg / mm ² (22 ° C.), more preferably 30 to 35 Kg / mm. ² The outer diameter of the distal end portion 2b of the inner core 2 is 0.03 to 0.15 mm, more preferably 0.05 to 0.10, and the length is 10 to 300 mm, preferably 50 to 1 mm.
50 mm, and the bending load is 0.1 to 10 g, preferably 0.3 to 6.0 g,
The restoration load is 0.1 to 10 g, preferably 0.3 to 6.0 g. In addition, the outer diameter of the distal end portion of the inner core does not need to be the above-mentioned size, and may be a part. Further, the restoring stress of the main body and the tip does not have to have the same value, but rather it is preferable to change it according to the heat treatment conditions so as to obtain appropriate physical properties at an appropriate wire diameter. That is, it is preferable to separate the heat treatment between the main body and the tip so that the restoring stress of the main body is large and the tip is flexible. Further, the inner core 2 is not limited to a single wire, but may be a plurality of wires that are parallel or twisted to exhibit the above-described function, that is, a stepwise or continuous change in physical properties. In the embodiment shown in FIGS. 1 and 2, the high X-ray contrast section 3 covers the outer peripheral surface of the tip of the inner core 2 as shown in FIGS. It is a fixed metal annular member having high X-ray contrast, and is specifically formed of a pipe-shaped member. As the metal having high X-ray contrast, gold, platinum, lead, silver, bismuth, tungsten, and the like are preferable, and gold is particularly preferable. The high X-ray contrast part 3 is fixed by mechanical crimping to the tip of the inner core 2 or by soldering to a metal plated or deposited on the tip of the inner core 2.
As the metal to be plated or vapor-deposited, when the inner core 2 is a TiNi alloy, Ni or the same kind of high X-ray contrast metal to be used is preferable, and a Cu—Zn alloy or a Cu—Zn—X alloy is used. In the case, Zn or the same kind as the high X-ray contrast metal to be used is preferable, and in the case of a Ni-Al alloy, Ni or the same kind as the high X-ray contrast forming metal to be used is preferable. It is. As the solder, a hard solder such as a silver solder or a gold solder can be preferably used. The high X-ray contrast part 3 has an outer diameter of 0.20 to 0.90 mm, preferably 0.1 to 0.90 mm.
25 to 0.40 mm, inner diameter 0.04 to 0.16 mm, preferably 0.06 to 0
. 11 mm, 1.00 to 10.00 mm in length, preferably 1.5 to 4.0 mm
It is. The high X-ray contrast section 3 may be, for example, one as shown in FIG. In the embodiment shown in FIG. 3, a thin wire formed of a metal having high X-ray contrast as described above is wound around the tip of the inner core 2 in a coil shape. As this fine wire, a wire having a wire diameter of 0.02 to 0.10 mm is suitably used. The length to be wound is 1.0 to 10.0 mm from the tip of the inner core, preferably 1.5 to 4.0 mm.
It is. As a method of forming such a coiled high X-ray contrast portion, a method of directly winding a fine wire on the inner core as described above, and a method of attaching a coil-shaped one to the tip of the inner core, etc. It is also preferable to securely fix them to the tip of the inner core. As a method, it is preferable to fix the wound or attached coil by pressing the coil from the outside. In addition, as another method, a metal for enhancing the adhesiveness to the high X-ray contrast part is plated or vapor-deposited on the tip of the inner core, and the above-mentioned fine wire is wound thereon or formed into a coil. Or by soldering. Generally, the coil body is easily deformed, and if the deformation is equal to or less than a predetermined stress value, the coil body is elastically deformed. Therefore, if the high X-ray contrast part is such a coil-shaped part,
Does not significantly impede the flexibility of the guidewire tip. And by having such a high X-ray contrast part, the visibility of the tip of the guide wire under X-ray fluoroscopy is improved. Further, the coil body formed of the above-described material is plastically deformed when a stress equal to or more than a predetermined stress value is applied. That is, the distal end of the coil body can be deformed by bending the coil body so as to be pulled by a finger or the like. By deforming the distal end of the guide wire into a desired shape in this way, the guide wire is adapted to the blood vessel bifurcation shape, and insertion into the blood vessel is facilitated. The materials forming the above-described coil body, such as gold, platinum, lead, silver, bismuth, and tungsten, have high X-ray contrast and the above-described plastic deformability, and maintain the deformed tip shape. I do. Further, in addition to the above, the high X-ray imaging part 3 is provided with a high X-ray imaging metal foil applied to the tip of the inner core and pressed, and a high X-ray imaging metal is plated or deposited on the tip. May be used to form a high X-ray contrast metal layer. The above metal foil, plating and vapor deposition preferably have a thickness of 50 μm or more. Further, as shown in FIG. 1, the synthetic resin film 4 covering the entire inner core 2 has a substantially uniform outer diameter including the tip. In particular, the synthetic resin film 4 has a substantially uniform outer diameter such that a step or the like due to a high X-ray contrast portion provided at the tip of the inner core 2 does not affect the outer surface shape of the guide wire 1. In addition, synthetic resin coating (coating part)
The high X-ray imaging part 3 may be provided so as to cover only the high X-ray imaging part 3, and when the high X-ray imaging part 3 is a coil body, It may be provided to cover. As the synthetic resin film 4, polyethylene, polyvinyl chloride, polyester, polypropylene, polyamide, polyurethane, polystyrene, fluororesin, silicone rubber, or their respective elastomers and composite materials are preferably used. It is preferable that the synthetic resin film 4 is flexible enough not to hinder the curvature of the inner core 2 and that the outer surface has a smooth surface without irregularities. Further, the synthetic resin film 4 is coated with an anticoagulant such as heparin or urokinase or an antithrombotic material such as silicone rubber, a block copolymer of urethane and silicone (registered trademark Abcosan), or a hydroxyethyl methacrylate-styrene copolymer. Thus, the surface may have antithrombotic properties. Further, the synthetic resin film 4 is formed of a resin having a low friction surface such as a fluororesin.
By applying a lubricating liquid such as silicone oil to the outer surface of the guide wire 1, the friction property of the guide wire 1 may be reduced. Further, it is preferable to mix a fine powdery X-ray opaque substance made of a single metal or a compound such as Ba, W, Bi, or Pb into the synthetic resin forming the synthetic resin film 4. The position of the entire guide wire 1 being introduced into the blood vessel can be easily confirmed. As described above, the synthetic resin film 4 preferably has a substantially uniform outer diameter. The term “substantially uniform” is not limited to complete uniformity, but may have a slightly smaller tip end. In this way, by making the distal end portion substantially uniform, it is possible to reduce damage that the distal end of the guide wire may give to the inner wall of the blood vessel. The outer diameter of the synthetic resin film is 0.25 to 1.04 mm, preferably 0.30 to 0.
The thickness of the inner core 2 on the main body 2a is 0.25 to 1.04 mm, preferably 0.30 to 0.64 mm. Further, it is preferable that the synthetic resin coating 4 is adhered to the inner core 2 in a state of close contact with the inner core 2 by a synthetic resin, and is also fixed to the distal end portion and the base end portion of the inner core 2.
Further, the synthetic resin film 4 is formed of a hollow tube, and the distal end portion and the proximal end portion of the inner core 2 or
An appropriate portion of the inner core may be fixed to the inner core 2 by bonding or melt molding. The distal end of the guide wire 1 (the distal end of the synthetic resin coating 4) has a curved surface such as a hemisphere as shown in FIG. 1 in order to prevent damage to the blood vessel wall and to improve the operability of the guide wire 1. Is preferred. Further, a lubricating substance is fixed on the surface of the synthetic resin film 4. The lubricating substance refers to a substance having lubricity when wet. Specifically, there is a water-soluble polymer substance or a derivative thereof. The lubricating substance is fixed to the surface of the synthetic resin by a covalent bond or an ionic bond. Then, the lubricant material is a polymeric material having no crosslinked principle chain, -OH, -CONH _2, -COOH, -
It has a hydrophilic group such as NH ₂ , —COO ⁻ , and —SO ³⁻ . Further, the lubricating substance contains water when wet (for example, at the time of blood contact) and exhibits lubricity. By fixing such a lubricating substance to the synthetic resin coating 4 which is the outer surface of the guidewire 1, the friction between the inner wall of the catheter and the outer surface of the guidewire during introduction of the catheter is reduced, and the sliding of the guidewire in the catheter is reduced. Because mobility is improved,
The operation of the guide wire becomes easy. Specifically, as natural water-soluble polymer substances, carboxymethyl starch, starch-based such as dialdehyde starch, cellulose-based such as carboxymethylcellulose, hydroxyethylcellulose, tannin, lignin-based, alginic acid, gum arabic heparin, chitin, chitosan and the like Polysaccharides, gelatin, and proteins such as casein. Synthetic water-soluble polymer substances include polyvinyl alcohol, polyalkylene oxide, polyethylene oxide, polyalkylene glycol, polyethylene glycol, acrylic acid, sodium polyacrylate, maleic anhydride, and methyl vinyl ether anhydride. Maleic acid copolymer, methyl vinyl ether sodium maleic anhydride, methyl vinyl ether maleic anhydride ammonium salt, maleic anhydride ethyl ester copolymer, phthalic acid, polyhydroxyethyl phthalate, water-soluble polyester, polydimethylolpropion Acid esters and acrylamides include polyacrylamide hydrolyzate, polyacrylamide quaternary, polyvinylpyrrolidone, polyethyleneimine, polyethylenes Honeto, such as water-soluble nylon is considered. Preferably, maleic anhydride is used, and particularly, maleic anhydride ethyl ester copolymer is suitable. Further, the derivative of the water-soluble polymer substance is not limited to water-soluble, and may be insolubilized as long as it has the above-mentioned water-soluble polymer substance as a basic structure, and may be hydrated when wet. Any material that exhibits lubricity can be used. For example, in the case of the water-soluble polymer substance, addition, substitution, oxidation, esterification compounds obtained by a reduction reaction, etc., salts, amidides, anhydrides, halides, ethereal compounds, hydrolysates, acetal compounds, formal compounds, Alkylol compound, quaternary compound, diazo compound, hydrazide compound, sulfonated compound, nitrated compound, ion complex, diazonium group, azide group, isocyanate group, acid chloride group, acid anhydride group, imino carbonate group, amino group Cross-linked products with substances having two or more reactive functional groups such as carboxyl groups, epoxy groups, hydroxyl groups, aldehyde groups, etc., and vinyl compounds, acrylic acid, methacrylic acid, diene compounds, maleic anhydride, etc. Polymers and the like are conceivable. In addition, the synthetic resin has a reactive functional group that forms an ionic or covalent bond with a lubricating substance as described below, or contains a compound having a reactive functional group, or has a reactive functional group introduced therein. . By the reactive functional group present or introduced in the synthetic resin and the above-mentioned lubricating substance being bonded, it is possible to impart lubricity on the synthetic resin surface, and it can be sustained without being dissolved in water. A lubricious surface can be obtained. Here, the description will be made based on a covalent bond. The lubricating substance is not particularly limited, but the above-mentioned cellulose-based, maleic anhydride-based, acrylamide-based, polyethylene oxide-based, water-soluble nylon and the like are preferably used. Particularly, hydroxypropyl cellulose, methyl vinyl ether, maleic anhydride copolymer, polyacrylamide, polyethylene glycol, water-soluble nylon (AQ-nylon P-70 manufactured by Toray Industries, Inc.)
And the like are preferred. The average molecular weight of these lubricating substances is not particularly limited, but is 3 to
A lubricating layer having a lubricating property of about 5 million is preferable because it has high lubricity, has an appropriate thickness, and does not have a remarkably large swelling degree when containing water. Examples of the lubricating substance fixed on the surface of the synthetic resin by ionic bonding include carboxylate, sulfonate, and ammonium salt of the above-mentioned water-soluble polymer substance in addition to polyvinylpyrrolidone. Examples of the carboxylate include sodium salt of methyl vinyl ether maleic anhydride, sodium polyacrylate, polyacrylamide hydrolyzate, sodium carboxymethyl cellulose, sodium alginate, and the like, and examples of the sulfonate include sodium polystyrene sulfonate and sodium polyvinyl sulfonate. And ammonium salts such as ammonium salt of methyl vinyl ether maleic anhydride and quaternary polyacrylamide. The reactive functional group present in the synthetic resin is not particularly limited as long as it reacts with the lubricating substance and bonds or cross-links to fix the diazonium group.
Azide group, isocyanate group, acid chloride group, acid anhydride group, imino carbonate group, amino group, carboxyl group, epoxy group, hydroxyl group, aldehyde group, etc. are considered, and especially isocyanate group, amino group, aldehyde group, epoxy group Is preferred. Therefore, as the synthetic resin having a reactive functional group, polyurethane, polyamide and the like are preferable. Examples of the substance having a reactive functional group include isocyanates such as methylene diisocyanate, ethylene diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate, and adducts or prepolymers of these isocyanates and polyols. Further, for example, ethylenediamine, trimethylenediamine, 1.2-diaminopropane as low molecular weight polyamine,
Tetramethylene diamine and the like can be considered. [I] a poly (alkylene polyamine) synthesized from an amine and an alkylenedihalide or epichlorohydrin as a high molecular weight polyamine, [II] an alkyleneimine polymer obtained by ring-opening polymerization of an alkyleneimine such as ethyleneimine or propyleneimine, [III] In addition, there are polyamines such as polyvinylamine and polylysine, polyaldehydes such as glutaraldehyde and terephthalaldehyde, and polyepoxides such as ethylene glycol diglycidyl ether. Next, examples of the guide wire of the present invention will be described. The inner core has a total length of 1800 mm, a tip diameter of 0.06 mm, and a rear end diameter of 0.
. A 25 mm tapered tapered 120 mm from the tip toward the tip was created. As the material of the inner core, a TiNi alloy of 51% Ni was used. Then, a pipe-shaped member having an inner diameter of 0.07 mm, an outer diameter of 0.3 mm, and a length of 2.0 mm is made of pure gold, inserted into the tip of the inner core, sandwiched using a jig, and pressed against the inner core. It was fixed and a high X-ray contrast part was formed. Further, the outer surface of the entire inner core was coated with a polyurethane containing 45% by weight of tungsten fine powder (particle size: about 3 to 4 μm) so that the entire outer diameter became substantially uniform, thereby forming a synthetic resin film. Then, a solution of a maleic anhydride ester copolymer dissolved in tetrahydrofuran so as to have a concentration of 5.0% by weight is applied to the surface of the synthetic resin film formed of the above polyurethane, and the maleic anhydride ethyl ester copolymer is dissolved. The coalescence was fixed to form a lubricious surface. This guide wire has an overall length of about 1800 mm and an overall diameter of 0.36
mm, the bending load at the tip of the guide wire was about 4 g, and the restoring load was about 2 g. When the entire guidewire was X-rayed, a high X
A line contrast image was obtained. Next, the operation of the guide wire of the present invention will be described with reference to the embodiment shown in FIG. The guide wire 1 is introduced into a blood vessel together with the catheter in a state where the distal end of the guide wire is protruded from the distal end of the catheter (not shown), and the distal end of the guide wire 1 guides the distal end of the catheter. Is inserted into a predetermined blood vessel site. At this time, the guide wire and the catheter are advanced while the distal end of the guide wire 1 and the catheter are confirmed from the outside by X-ray contrast.
After the distal end of the catheter has reached near the target site, the guide wire is removed from the catheter. According to the guide wire of the present invention, an inner core in which a main body having high rigidity, a distal end having a smaller diameter than the main body and having low rigidity are integrally formed, and an outer periphery of a distal end of the inner core are provided. Envelop the surface,
And a high X-ray contrast part made of a metal having high X-ray contrast fixed to the tip of the inner core, and the high X-ray contrast part being in close contact with the entire inner core to which the high X-ray contrast part is fixed and the entire inner core A synthetic resin film encapsulating the material, the synthetic resin film having a lubricating substance having lubricity when wetted on the surface, and in particular, at the tip of the inner core, a high X-ray contrast portion is provided. Since the position of the tip can be reliably grasped under X-ray contrast,
The introduction of the guide wire and the subsequent operation of introducing the catheter can be easily performed. In addition, since the lubricating substance is fixed to the synthetic resin coating, which is the outer surface of the guidewire, the friction between the inner wall of the catheter and the outer surface of the guidewire during introduction of the catheter is reduced, and the sliding property of the guidewire in the catheter is reduced. , The operation of the guide wire is facilitated. In addition, the inner core is made of a superelastic alloy, and the tip is made to have a small diameter, so that the tip is relatively displaced under a constant stress and has elastic strain characteristics that can be restored. It can be. Therefore, when the distal end portion advances along the bent portion of the blood vessel, a large bending deformation is easily generated with a relatively small load, so that the responsiveness of the distal end portion is good, and the bent portion of the blood vessel is not damaged. The curve deformation and its restoration are repeated in response to the change of the shape, the shape adaptability to the meandering blood vessels is good, and the blood vessels are relatively easily curved, and can be easily introduced into the predetermined blood vessel site. it can. Further, the guide wire has a good torque transmitting property in the main body portion in both torsion directions, and can securely and easily direct the distal end portion toward a predetermined blood vessel portion by the torque applied to the main body portion. Good insertion operability into the site.

[Brief description of the drawings]     FIG.   FIG. 1 is a sectional view of one embodiment of the guide wire of the present invention.     FIG. 2   FIG. 2 is an enlarged sectional view taken along line II of FIG.     FIG. 3   FIG. 3 is a sectional view of another embodiment of the guide wire of the present invention.     [Explanation of symbols] 1 guide wire 2 inner core 3 High X-ray contrast material 4 Synthetic resin coating

Claims (1)

Claims: 1. An inner core integrally formed with a highly rigid main body, a thinner distal end having a smaller diameter than the main body, and an outer peripheral surface of a distal end of the inner core. And a high X-ray imaging part made of a metal having high X-ray imaging property fixed to the tip of the inner core, and the whole of the inner core to which the high X-ray imaging part is fixed is adhered. And a synthetic resin film encapsulating the entire inner core. The synthetic resin film has a lubricating substance having lubricity when wet on the surface, and the synthetic resin film has a fine powdery X-ray contrast property. A guide wire comprising a synthetic resin mixed with a substance. 2. An inner core in which a highly rigid main body, a thinner tip than the main body and a lower rigidity are integrally formed, and an outer peripheral surface of a tip of the inner core is encapsulated, and A high X-ray imaging part made of a metal having high X-ray imaging property fixed to the tip of the inner core; and the entire inner core fixedly adhered to the entire inner core to which the high X-ray imaging part is fixed. A guide wire, comprising a synthetic resin film to be encapsulated, the synthetic resin film having a lubricating substance having lubricity when wetted on the surface, and the high X-ray imaging part being a coil. 3. An inner core in which a main body part having high rigidity, a tip part having a smaller diameter than the main body part and having low rigidity are integrally formed, and an outer peripheral surface of a tip end of the inner core is encapsulated, and A high X-ray imaging part made of a metal having high X-ray imaging property fixed to the tip of the inner core; and the entire inner core fixedly adhered to the entire inner core to which the high X-ray imaging part is fixed. A guide comprising: a synthetic resin film to be encapsulated; said synthetic resin film having a lubricating substance having lubricity when wetted on the surface, and wherein said high X-ray contrast section is a pipe-shaped member. wire. 4. An inner core integrally formed with a highly rigid main body, a thinner distal end having a smaller diameter than the main body, and an outer peripheral surface of a distal end of the inner core. A high X-ray imaging part made of a metal having high X-ray imaging property fixed to the tip of the inner core; and the entire inner core fixedly adhered to the entire inner core to which the high X-ray imaging part is fixed. A synthetic resin film to be encapsulated, the synthetic resin film having a lubricating substance having lubricity when wet on the surface, and the high X-ray contrast portion is formed by plating or vapor-depositing a high X-ray contrast metal. A guide wire, which is formed. 5. An inner core in which a main body part having high rigidity, a tip part having a smaller diameter than the main body part and having low rigidity are integrally formed, and an outer peripheral surface of a tip end of the inner core is encapsulated, and A high X-ray imaging part made of a metal having high X-ray imaging property fixed to the tip of the inner core; and the entire inner core fixedly adhered to the entire inner core to which the high X-ray imaging part is fixed. A synthetic resin film to be encapsulated, the synthetic resin film having a lubricating substance having lubricity when wet on the surface, and the tip of the inner core having a gradually decreasing diameter toward the tip. A guide wire formed on a guide wire. 6. An inner core integrally formed with a highly rigid main body, a thinner tip than the main body, and a lower rigidity, and enclosing an outer peripheral surface of a tip of the inner core, and A high X-ray imaging part made of a metal having high X-ray imaging property fixed to the tip of the inner core; and the entire inner core fixedly adhered to the entire inner core to which the high X-ray imaging part is fixed. A synthetic resin film to be encapsulated, wherein the synthetic resin film has a lubricating substance having lubricity on the surface when wet, and the inner core is integrally formed of a TiNi alloy. Guide wire.