JP2002233574A - Guide wire with marker at end portion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the operation of introducing a catheter into a target part by providing an end portion of a guide wire with an advanced function of X-ray imaging. SOLUTION: This guide wire has a metal having an advanced function of X-ray imaging, provided at the end of an end core 2b. The guide wire has a film 4 of synthetic resin making intimate contact with both an advanced X-ray imaging part formed of the metal and the core and having a uniform outside diameter, except at least at the end of the advanced X-ray imaging part 3, with the outside diameter of the metal being approximately equal to the outside diameter of a body side core 2b having the film 4 thereon. The metal is in the form of an annular member which is either a coil- or pipe-shaped member. The advanced X-ray imaging part 3 has a metal layer of advanced X-ray imaging properties which is formed on its outer surface by plating or vapor deposition. The end core 2b tapers toward an end and is preferably made of a pseudoelastic alloy or a superelastic alloy. Further, a pulverized X-ray imaging substance is mixed into at least the end portion of the film of synthetic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guide wire used for introducing a catheter to a required site in a body for treatment or examination. More specifically, even when formed into a thinner guide wire, the distal end thereof has a high X-ray contrast function, and can be used to easily introduce a catheter, an indwelling tube, and the like to a target site. It relates to a guide wire.

[0002]

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 such a catheter is introduced into a target site in the body, a guide wire is inserted into the catheter. , And the distal end of the guide wire is made to slightly protrude from the distal end of the catheter, and the catheter is guided to the target site by the guide wire. As a guide wire for a catheter used for such a purpose, for example, JP-A-60-7862
And Japanese Patent Application Laid-Open No. Sho 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 covered with a synthetic resin. It has been shown that this guidewire has excellent catheter guideability by having high flexibility and restoring properties at the distal end.

On the other hand, as shown in FIGS. 12 and 13, the inner core 2 of the conventional guide wire 1 has a body-side inner core portion 2a and a distal-end inner core portion 2b which are integrally formed. The distal inner core 2b is formed in a tapered shape toward the distal end, and the entire inner core 2 is covered with a synthetic resin 4 so as to have the same diameter.
Has a high X-ray contrast part 3 at the tip. The high X-ray imaging unit 3 is configured by coating the tip with a synthetic resin mixed with a fine powdery high X-ray imaging substance, and moves in a blood vessel by the high X-ray imaging unit 3. At this time, the position of the tip can be confirmed. FIG. 13 is a sectional view taken along line II of FIG.

[0004]

However, although the guide wire as described above has an extremely excellent effect in terms of catheter guideability, the guide wire used for introduction into a conventional thin blood vessel is used. Has a high X-ray contrast part 3 at the tip of the inner core, but has a problem that the X-ray contrast at the tip is particularly poor because the tip of the inner core is thinner. . Therefore, in order to improve the contrast property, it is conceivable to include an X-ray contrast substance in the synthetic resin coating the inner core of the guide wire. And the overall X-ray imaging function was not very high.

In particular, recently, thinner blood vessels, for example,
It has been considered to introduce a catheter into a thin blood vessel such as an inner blood vessel of the brain or a blood vessel constituting a kidney, so that the diameter of the catheter is further reduced, and the diameter of the guide wire is also required to be reduced. For this reason, it cannot be denied that the guide wire of the type in which the inner core is coated with the synthetic resin further deteriorates the X-ray contrast at the distal end and makes it difficult to introduce the catheter into the target site. .

Accordingly, the present inventors have studied variously the markers formed on a smaller-diameter guide wire, and have found a smaller-diameter guide wire having an excellent X-ray contrast function without the above-mentioned problems. Is found to be obtained,
The present invention has been accomplished. Therefore, the problem to be solved by the present invention is that even when a guide wire having a smaller diameter is formed, the distal end thereof has a high X-ray contrast function, and it is easy to introduce a catheter into a target site. The object of the present invention is to provide a guide wire for a catheter which can be used.

[0007]

The above object is achieved by the present invention comprising the following constituent elements.

(1) An inner core in which a highly rigid body-side inner core, a smaller-rigidity inner core having a smaller diameter than the body-side inner core are integrally formed, It is made of a metal having high X-ray contrast provided at the distal end of the core portion, and at least the distal end side of the high X-ray contrast portion is in close contact with the high X-ray contrast portion formed of the metal and the inner core. With a synthetic resin coating having a substantially uniform outer diameter that covers the entire inner core except for
A guide wire, wherein the outer diameter of the metal is substantially the same as the outer diameter of the inner core portion having a synthetic resin coating. (2) The guide wire according to (1), wherein the metal of the high X-ray imaging part is formed of an annular member. (3) The guide wire according to (2), wherein the annular member is formed of a coil or a pipe-shaped member. (4) The high X-ray contrast part has a metal layer having a high X-ray contrast property formed on the outer surface by plating or vapor deposition.
2. The guidewire according to claim 1, wherein the guidewire comprises a line contrast part. (5) The guide wire according to any one of (1) to (4), wherein the distal end side inner core portion is tapered toward the distal end. (6) The guide wire according to any of (1) to (5), wherein the inner core is formed of a pseudoelastic alloy. (7) The guidewire according to any one of (1) to (6), wherein the pseudoelastic alloy is a superelastic alloy. (8) The guide wire according to any one of (1) to (7), wherein a fine powdery X-ray opaque substance is mixed in at least a tip portion of the synthetic resin film.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a guide wire according to the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing one embodiment of the guide wire of the present invention, and FIG. 2 is a longitudinal sectional view of FIG. 1 and 2, an inner core 2 of a guide wire 1 according to the present invention has a highly rigid main body side inner core portion 2a and a thinner rigid body having a diameter smaller than that of the main body side inner core portion 2a and reduced toward the distal end. The lower tip side inner core portion 2b is integrally formed. A high X-ray contrast part 3 is provided at the tip of the inner core 2, and the inner core 2 covers a part of the high X-ray contrast part 3 and substantially covers the entire inner core 2. And a synthetic resin film 4 having a diameter. The outer diameter of the high X-ray contrast part 3 is substantially the same as the outer diameter of the inner core part having the synthetic resin film. Specifically, as shown in FIGS. 1 and 2, the spherical body 30 of the high X-ray contrast part 3 is an example in which a part thereof is covered with a synthetic resin film 4.

FIGS. 3 to 7 are sectional views showing other modified examples of the inner core 2 of the guide wire 1 according to the present invention.
FIG. 2 shows an inner core 2 of the guide wire 1 shown in FIG. 2, and has a high X-ray contrast part 3 made of a spherical body 30 at the tip of the inner core. In FIG. 4, the inner core 2 has the same shape as the inner core 2 shown in FIG. 3, but the shape of the high X-ray contrast part 3 provided at the tip is a hemispherical body 31. The high X-ray contrast part 3 shown in FIG. 5 has a raindrop shape 32, and in FIG. 6, the high X-ray contrast part 3 has a rounded bullet 33.

Furthermore, in FIG. 7, the high X-ray contrast part 3 is a hemisphere 31, but the inner core 2 has the same diameter as the inner core part 2b on the tip side smaller than the inner core part 2a on the main body side. The main body side inner core portion 2a having the same diameter is connected by a connection portion 2c. The connecting portion 2c is preferably formed in a tapered shape from the inner core 2a on the main body side toward the inner core 2b on the distal end side. In the present invention, the high X-ray contrast part 3 is provided at the tip of the inner core 2, and is made of metal having a shape larger than the diameter of the tip. As a result, when a catheter is introduced into a required site in the body for treatment or examination, even if the catheter is formed into a smaller diameter guide wire, the distal end has a high X-ray contrast function and can be used for a target site. This provides an excellent effect that the catheter introduction operation can be easily performed.

As shown in FIG. 2, the inner core 2 shown in FIGS. 3 to 7 is covered with a synthetic resin coating 4 except for at least a part of the high X-ray contrast part 3, and the inner core 2 is made of the same material. It goes without saying that the core 2 is used in the form of a guide wire 1 covered with a synthetic resin film 4.

FIG. 8 is a side view showing another embodiment of the present invention. In FIG. 8, the distal end portion of the guide wire 1 manufactured using the inner core 2 shown in FIGS. Used by bending to FIGS. 9 to 11 show a high X-ray imaging part 3 of a coil shape 35 near the distal end of the distal inner core 2b.
a consisting of a guide wire provided with a.
Further, at the tip thereof, a high X-ray contrast part 3 having a hemispherical shape 31 is provided. Since it has a diameter substantially the same as the outer diameter of the body-side inner core portion covered with, it has an extremely high X-ray contrast function. FIG.
The high X-ray imaging part 3a of the coil shape 35 is provided so as to cover a part of the inner core 2 at the distal end portion.
Are covered with a synthetic resin film 4. FIG.
It is an enlarged view of A of FIG.

The inner core 2 of the guide wire 1 according to the present invention comprises an inner core 2a on the main body side and an inner core 2b on the distal end, and at least the distal inner core 2b on the distal end is pseudoelastic. It is integrally formed of an alloy. The characteristic of the tip portion (the tip-side inner core portion covered with a synthetic resin film) in which the tip-side inner core portion 2b is formed in a tapered shape with this pseudoelastic alloy, the strain gradually increases as the stress increases. Characteristic appears. Thus, the distal-side inner core 2b is
It is preferable that the diameter is gradually reduced from the main body side inner core portion 2a toward the distal end. Further, the pseudoelastic alloy may be a superelastic alloy, and the characteristic of the superelastic alloy is that the magnitude of the stress does not change even if the strain increases under a constant stress. This characteristic shows that when the diameter of the tip side inner core portion 2b is the same due to the shape of the superelastic alloy, the stress does not change even if the strain increases under a constant load. When the diameter of the side inner core portion 2b changes in a tapered shape, a characteristic is obtained in which the strain gradually increases as the load increases.

As shown in FIG. 7, the distal inner core 2b
By reducing the diameter to the same diameter, it is possible to obtain a rigid body having a lower rigidity than the main body side inner core portion 2a, increase the strain under a constant stress (or load), and remove the stress (or load). The tip-side inner core 2b formed of a superelastic alloy having a characteristic of returning to the original strain exhibits a characteristic in which the distortion increases in response to the stress and returns to the original state when the stress is removed.
As described above, when a superelastic alloy having a characteristic in which the strain increases according to the stress and the strain returns to the original state when the stress is removed is used, the tip side inner core portion formed of the superelastic alloy is used. 2b
Exhibits a characteristic in which the strain increases under a constant stress and the strain returns to the original state when the stress is removed. Further, by gradually reducing the diameter of the inner core portion 2b on the distal end side, when a force is applied to the distal end, the distal end portion is gradually bent, so that the operability is improved.

As the inner core 2 used in the present invention, 49
-58 atomic% Ni TiNi alloy, 38.5-41.5
Weight% Zn Cu-Zn alloy, 1-10 weight% X Cu
-Zn-X alloy (X = Be, Si, Sn, Al, G
a) A pseudoelastic alloy or a superelastic alloy 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 side inner core portion 2a is 0.10 to 1.00 mm, more preferably 0.15 to 0.40 mm, and the length is 1000
~ 4000mm, more preferably 1500 ~ 3000m
m. As described above, the guide wire inner core made of these alloys has the property that the strain increases under a constant stress, and has the property of completely or almost returning to the original state when the stress is removed, and the As the strain increases,
Those having the property of completely or almost returning to the original state when the stress is removed can be selected and used. Further, since the above two properties can be realized depending on the shape of the inner core of the guide wire formed of the superelastic alloy, those properties can be selected by changing the shape of the inner core.

When the outer diameter of the inner core portion 2b on the tip side is the same outer diameter, 0.03 to 0.15 mm, more preferably,
0.05 ~ 0.10mm, length is 10 ~ 300m
m, preferably 50-150 mm, and the bending load is
0.1 to 10 g, preferably 0.3 to 6.0 g, and the restoration load is 0.1 to 10 g, preferably 0.3 to 6.0 g. When the distal-side inner core portion 2b is formed in a tapered shape, the outer diameter of the main-body-side inner core portion 2a ranges from 0.10 to 1.0.
It is 00 mm, more preferably 0.15 to 0.40 mm, and the length is 1000 to 4000 mm, more preferably 1500 to 3000 mm. This main body side inner core 2a
The outer diameter of the tip when the diameter is reduced in a tapered shape from the outer diameter of the tip to the outer diameter of the tip of the tip side inner core portion 2b is 0.03 to 0.15
mm, more preferably 0.05 to 0.10 mm, and a length of 10 to 300 mm, preferably 50 to 150 mm.
mm.

Further, the outer diameter of the distal end portion of the inner core does not need to be the above-mentioned size, and is not limited to this size. Further, the rigidity and flexibility of the main body portion and the tip portion do not need to have the same value, but rather it is preferable to devise them according to heat treatment conditions so as to obtain appropriate physical properties at an appropriate wire diameter. Further, it is preferable to separate the heat treatment between the main body and the distal end so that the rigidity of the main body is high and the distal end 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.

The high X-ray contrast part 3 used in the present invention is formed of a metal having high X-ray contrast or a plastic whose surface is coated with a metal having high X-ray contrast by plating or vapor deposition. FIGS. 1 to 4 and 7 show a hemispherical shape 31 and a spherical shape 34, but FIGS. 5 to 6 and FIGS. 9 to 11 show an annular member. Specifically, FIGS. In FIG. 6, the pipe-shaped member, in particular, the pipe-shaped member is further deformed and formed into a raindrop shape or a bullet shape. However, the annular member may be in the form of a coil. Further, the outer diameter of the high X-ray imaging part 3 is preferably equal to or larger than the outer diameter of the inner core part 2a of the inner core, and is preferably equal to or slightly smaller than the outer diameter of the guide wire. It is good to form small. Normally, high X-ray imaging unit 3
Has an outer diameter of 0.20 to. 90 mm, preferably 0.35
0.70 mm, inner diameter 0.04 to 0.16 mm, preferably 0.06 to 0.11 mm, length 1.00 to 1
It is 0.00 mm, preferably 1.5 to 4.0 mm.
It is preferable that the high X-ray contrast part 3 is fixed to the tip of the tip part whose diameter is reduced in a tapered shape. As the metal having high X-ray contrast, gold, platinum, lead, silver, bismuth, tungsten and alloys containing these metals as main components are preferable, and platinum and gold are particularly preferable.

The high X-ray contrast part 3 is inserted into the front end of the inner core 2 and then fixed by mechanical crimping, or is made of metal or plastic to be an X-ray contrast part provided at the front end of the inner core 2. For example, a metal having high X-ray contrast may be plated or vapor-deposited on the outer surface of the substrate. Among these, when the X-ray contrast part is metal, it is preferable to fix it by soldering, and when it is plastic, it is preferable to use an adhesive. As the metal to be plated or 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 Cu—Zn—X In the case of an alloy, Zn or the same kind as the high X-ray contrast metal to be used is suitable, and in the case of a Ni-Al alloy, N
i or the same kind as the high X-ray contrast-enhancing metal to be used is preferable. As the solder, a hard solder such as a silver solder or a gold solder can be preferably used.

As shown in FIGS. 9 to 11, the outer diameter of the high X-ray contrast part 3 used in the present invention is the same as the outer diameter of the inner core 2a on the main body side. Or, it is large and is fixed to the tip of the tip side inner core portion 2b which is tapered and reduced in diameter. In this example, a thin wire made 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 0.1 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 m.
m.

In the present invention, such a coil 35
As a method for forming the high X-ray contrast part 3, a method in which a fine wire is directly wound on the inner core as described above, a method in which a coil formed in a coil shape is attached to the tip of the inner core, and the like are considered. Further, it is preferable to securely fix them to the tip of the inner core. As a method for fixing them, it is preferable to fix the wound or attached coil by pressing the coil from the outside. In addition, as another method, metal plating or vapor deposition is applied to the tip of the inner core to enhance the adhesiveness to the high X-ray contrast part 3, and the above-mentioned fine wire is wound or formed into a coil shape. Or by soldering. 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 thickness of the metal foil, plating and vapor deposition is preferably 50 μm or more.

In the present invention, as shown in FIG. 2, the synthetic resin coating 4 covering the entire inner core 2 has a substantially uniform outer diameter including the tip. In particular, the synthetic resin coating 4 has a substantially uniform outer diameter so that a step or the like due to the high X-ray contrast part 3 provided at the tip of the inner core 2 does not affect the outer surface shape of the guide wire 1. Synthetic resin coating 4
Examples of suitable materials include polyethylene, polyvinyl chloride, polyester, polypropylene, polyamide, polyurethane, polystyrene, fluororesin, silicone rubber, and their respective elastomers and composite materials. 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.

After the inner core 2 is coated with the synthetic resin film 4, an anticoagulant such as heparin or urokinase, a silicone rubber, or a urethane-silicone block copolymer (registered trademark, Abucosan Co., Ltd.) ), An antithrombotic material such as hydroxyethyl methacrylate-styrene copolymer. Further, even if the synthetic resin film 4 is formed of a resin having a low friction surface such as a fluororesin, or the outer surface of the synthetic resin film 4 is coated with a lubricating liquid such as silicone oil, the friction of the guide wire 1 is reduced. Good. Further, it is preferable to mix a high X-ray contrast material in the form of a fine powder of a simple metal or a compound such as Ba, W, Bi, or Pb into the synthetic resin for forming the synthetic resin film 4. The position of the entire guide wire 1 being introduced into the blood vessel can be easily confirmed. The synthetic resin coating 4 has a substantially uniform outer diameter as described above. 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 coating is 0.25
1.04 mm, preferably 0.30 to 0.70 mm, and the thickness of the inner core 2 on the main body 2a is 0.25 to 1.04 m
m, preferably 0.30 to 0.64 mm.

It is preferable that the synthetic resin film 4 is adhered to the inner core 2 by a synthetic resin in a state of being in close contact with the inner core 2 and is also fixed at the end. Further, the synthetic resin film 4 is formed of a hollow tube, and is fixed to the inner core 2 by bonding or melt molding at the end of the high X-ray imaging section 3 and the end of the inner core 2b on the main body side or an appropriate portion of the inner core. May be. The distal end of the guide wire 1 (the distal end of the high X-ray contrast section 3) is used to prevent damage to the blood vessel wall and to improve the operability of the guide wire 1 as shown in FIGS. Imaging unit 3
Is preferably a curved surface such as a hemisphere.

In the present invention, it is preferable that 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. And this lubricating substance,
In principle, it is a chain-like, non-crosslinked polymer substance,
_{H, -CONH 2, -COOH, -NH} 2, -CO
O ^-, -SO ₃ ^- and has a hydrophilic group such as. 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. Since the mobility is improved, the operation of the guide wire is facilitated.

The lubricating substance used in the present invention may be, for example, a natural water-soluble polymer substance such as carboxymethyl starch, dialdehyde starch or the like, cellulosic such as carboxymethyl cellulose or hydroxyethyl cellulose, tannin, or the like. Polysaccharides such as lignin, alginic acid, gum arabic heparin, chitin and chitosan, and proteins such as gelatin and casein are considered. 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,
Examples of polydimethylol propionate and acrylamide include polyacrylamide hydrolyzate, polyacrylamide quaternary product, polyvinylpyrrolidone, polyethyleneimine, polyethylenesulfonate, and water-soluble nylon. Preferably, maleic anhydride is used, and particularly, maleic anhydride ethyl ester copolymer is suitable.

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 basic structure. Any material that sometimes contains water and exhibits lubricity can be used. For example, in the case of the above water-soluble polymer substance, addition,
Esterification products obtained by substitution, oxidation, reduction reaction, etc.,
Salts, amidates, anhydrides, halides, etherified compounds, hydrolysates, acetalized compounds, formalized compounds, alkylolated compounds, quaternized compounds, diazotized compounds, hydrazide compounds, sulfonated compounds, nitrated compounds, ion complexes, and diazonium Group, azide group, isocyanate group, acid chloride group, acid anhydride group, imino carbonate group, amino group, carboxyl group, epoxy group, hydroxyl group,
A crosslinked product with a substance having two or more reactive functional groups such as an aldehyde group, a copolymer with a vinyl compound, acrylic acid, methacrylic acid, a diene compound, maleic anhydride, and the like can be considered.

The synthetic resin has a reactive functional group that forms an ionic or covalent bond with a lubricating substance, contains a compound having a reactive functional group, or has a reactive functional group introduced therein, as described later. Have been. 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 preferable. The average molecular weight of these lubricating substances is not particularly limited, but those having a lubricating property of about 3 to 5,000,000 have a high lubricating property, an appropriate thickness, and a swelling degree when containing water is not remarkably large. It is.

Examples of the lubricating substance fixed to the surface of the synthetic resin by ionic bonding include, in addition to polyvinylpyrrolidone, carboxylate, sulfonate and ammonium salt of the above-mentioned water-soluble polymer substances. Specific examples of the carboxylate include sodium salt of methyl vinyl ether maleic anhydride, sodium polyacrylate, polyacrylamide hydrolyzate, sodium carboxymethylcellulose, sodium alginate, and the like, and the sulfonates include sodium polystyrene sulfonate and polyvinyl sulfonate. Examples include sodium sulfonate, and ammonium salts include ammonium salts of methyl vinyl ether maleic anhydride and quaternary polyacrylamide. In the synthetic resin, as the reactive functional group present, as long as it reacts with the lubricating substance and bonds or cross-links it,
Although there is no particular limitation, a diazonium group, an azide group, an isocyanate group, an acid chloride group, an acid anhydride group, an imino carbonate group, an amino group, a carboxyl group, an epoxy group, a hydroxyl group, an aldehyde group, and the like are considered. , An amino group, an aldehyde group and an epoxy group are preferred. Therefore, as a synthetic resin having a reactive functional group,
Polyurethane, polyamide and the like are preferred.

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. Furthermore, for example, ethylenediamine, trimethylenediamine, 1,2
-Diaminopropane, tetramethylenediain and the like. [I] poly (alkylene polyamine) synthesized from amine and alkylene dihalide or epichloro and hydrin as polymer polyamine, [II] alkylene imine polymer obtained by ring-opening polymerization of alkylene imine such as ethyleneimine and propyleneimine,
[III] In addition, polyamines such as polyvinylamine and polylysine. In addition, polyaldehydes such as glutaraldehyde and terephthalaldehyde. Further, there are polyepoxides such as ethylene glycol diglycidyl ether.

[0032]

DESCRIPTION OF THE PREFERRED EMBODIMENTS For better understanding of the present invention, embodiments of the guide wire of the present invention will be described below with reference to the drawings. However, the present invention is not limited to these examples. .

Example 1 As shown in FIG. 6, the total length is 1800 mm, the diameter of the tip is 0.06 mm, the diameter of the rear end is 0.25 mm, and 120 mm from the tip is shrunk in a Taber shape toward the tip. An inner core 2 having a diameter was prepared. As the material of the inner core 2, a superelastic alloy made of TiNi of 51% Ni was used. The tip-side inner core portion 2b from the tip to 120 mm has a characteristic that the strain increases as the stress increases. Next, pure gold was used as the metal having high X-ray contrast, with an inner diameter of 0.07 mm and an outer diameter of 0.35 m.
m, a pipe-shaped member having a length of 2.0 mm is prepared, the tip of the inner core 2 is inserted into the pipe-shaped member, sandwiched with a jig, and the pipe-shaped member is pressed and fixed to the inner core. An X-ray contrast part 3 was formed. Further, the entire outer surface of the inner core 2 was coated with polyurethane containing 45% by weight of tungsten fine powder (particle diameter: 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 with a synthetic resin coating. When an X-ray image of the entire guide wire was taken, a high X-ray contrast image was obtained at the distal end.

Using the obtained guide wire of the present invention, X-ray photography of the entire guide wire was performed as follows.
The guide wire is introduced into the blood vessel together with the catheter with its distal end protruding from the distal end of a catheter (not shown), and the distal end of the guide wire guides the distal end of the catheter to guide the catheter to a predetermined position. It was inserted into the vascular site. At this time, the guide wire and the catheter are advanced while confirming the distal end of the guide wire and the catheter from the outside by X-ray contrast, and after the distal end of the catheter reaches the vicinity of the target site,
The guide wire was removed from the catheter. When observing from the outside, this situation shows that the tip of the guidewire is clearly projected by X-ray contrast, and it is easy to confirm that the guidewire reaches the vicinity of the target site. Was.

Embodiment 2 As shown in FIGS. 1 to 3, the total length is 1800 mm, the tip diameter is 0.06 mm,
The inner core 2 having a diameter of 0.30 mm at the rear end and a diameter of 150 mm from the front end reduced in a Taber shape toward the front end was prepared. As a material of the inner core 2, Ti of 51% Ni is used.
A superelastic alloy made of Ni was used. 120 from this tip
The distal end side inner core portion 2b up to mm has a characteristic that the strain increases as the stress increases. Then, using pure gold as a metal having high X-ray contrast, an outer diameter of 0.46 mm
Of 0.07mm in diameter toward the center of the sphere
The spherical member provided with the hole was prepared, the tip of the inner core 2 was inserted into the hole of the spherical member, and bonded with an adhesive to form a high X-ray contrast part 3. Thereafter, in the same manner as in Example 1, a guide wire was prepared by applying a synthetic resin film, a lubricating substance, and other necessary treatments. This guide wire had an overall length of about 1800 mm and an overall diameter of 0.46 mm with a synthetic resin coating. When an X-ray image of the entire guide wire was taken, a high X-ray contrast image was obtained at the distal end. It should be noted that a guide wire produced in the same manner as in Example 1 using the inner core shown in FIG. 4 to FIG. 6 exhibited the excellent effect of the present invention.

[Embodiment 3] As shown in FIGS. 9 to 11, the total length is 2600 mm and the diameter of the tip is 0.06 m.
m, diameter of the rear end is 0.30 mm, 200 mm from the front end
The inner core 2 whose diameter was reduced in a taber shape toward the tip was prepared. As the material of the inner core 2, a superelastic alloy made of TiNi of 51% Ni was used. 2 from this tip
The tip side inner core portion 2b up to 00 mm has a characteristic that the strain increases as the stress increases. Next, as a metal having high X-ray contrast, pure gold was used, and it was made of a hemisphere having an outer diameter of 0.46 mm.
A hemispherical member provided with a hole having a depth of 0.08 mm was prepared, the tip of the inner core 2 was inserted into the hole of the spherical member, and bonded by brazing to form a high X-ray contrast part 3. Next, a wire made of pure gold was wound several times adjacent to the hemispherical member 3 to form a coil 35. Thereafter, in the same manner as in Example 1, a guide wire was prepared by applying a synthetic resin film, a lubricating substance, and other necessary treatments. At this time, two types were prepared, one in which the synthetic resin coating 4 covers the high X-ray contrast parts 3 and 3a and the other in which the coating was not coated. This guide wire had an overall length of about 1800 mm and an overall diameter of 0.46 mm with a synthetic resin coating. When an X-ray image of the entire guide wire was taken, a high X-ray contrast image was obtained at the distal end portion.
The insertion operation was easier with the guide wire in which the entire line contrast portion 3a and the inner core 2 were covered.

[0037]

According to the present invention, there is provided a guide wire in which a rigid inner body portion having a higher rigidity and a distal inner core portion having a smaller diameter than the main body side and having a lower rigidity are integrally formed. And a metal having high X-ray contrast provided at the distal end of the inner core portion on the distal end side, and further, a high X-ray contrast portion formed of the metal and at least a high X It is characterized by having a synthetic resin coating having a substantially uniform outer diameter that covers the entire inner core except for a part of the line contrast part. Since a high X-ray contrast part of the same size as the outer diameter of
Under radiography, the position of the tip can be more clearly and reliably grasped, so that the introduction of the guidewire and the subsequent introduction of the catheter can be easily performed.

Further, the inner core is made of a superelastic alloy, and the tip is made to have a small diameter so that the tip can be displaced relatively large by a smaller external load and can recover elastic strain characteristics. Can be provided. 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 portion is good, and the bent portion of the blood vessel is not damaged without damaging the blood vessel wall. Repeatedly deforms and restores in response to changes in the shape, has good shape adaptability to meandering blood vessels, bends relatively easily to blood vessel bifurcations, and introduces it into a predetermined blood vessel part without difficulty. Can be. further,
Since this guide wire has a main body made of a superelastic alloy, it has good torque transmission in both torsion directions,
The tip applied to the predetermined vascular site can be reliably and easily directed to the predetermined vascular site by the torque applied to the main body, and the operability of insertion into a complicated vascular site is good.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a guide wire of the present invention.

FIG. 2 is a sectional view showing the guide wire of the present invention of FIG. 1;

FIG. 3 is a cross-sectional view showing the shape of an inner core used in the present invention of FIG. 1 and a high X-ray contrast part provided in an inner core portion on a distal end side thereof.

FIG. 4 is a cross-sectional view showing another shape of the high X-ray contrast part provided at the tip of the inner core used in the present invention.

FIG. 5 is a cross-sectional view showing another example of the shape of the high X-ray contrast section provided at the tip of the inner core used in the present invention.

FIG. 6 is a cross-sectional view showing still another example of the shape of the high X-ray contrast part provided at the tip of the inner core used in the present invention.

FIG. 7 is a sectional view showing a shape of an inner core used in the present invention.

FIG. 8 is a perspective view showing a shape of a distal end portion of the guide wire of the present invention.

FIG. 9 is a perspective view showing another example of the guide wire of the present invention.

FIG. 10 is a sectional view showing the guide wire of FIG. 9;

11 is an enlarged sectional view showing A of the distal end portion of the guide wire of FIG. 10;

FIG. 12 is a cross-sectional view showing an X-ray contrast section provided at a distal end of a conventional guide wire.

FIG. 13 is a cross-sectional view showing a cross section taken along line II of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Guide wire 2 Inner core 2a Body side inner core part 2b Tip side inner core part 3, 3a High X-ray imaging part 30 Spherical body 31 Hemispherical body 32 Raindrop shape 33 Bullet shape 34 Spherical shape 35 Coiled member 4 Synthetic resin Coating

Claims (8)

[Claims] An inner core formed integrally with a main body-side inner core having high rigidity, a tip-side inner core having a smaller diameter than the main body-side inner core and having lower rigidity; A metal having high X-ray contrast provided at the tip of the portion, except for at least the tip side of the high X-ray contrast portion in close contact with the high X-ray contrast portion formed of the metal and the inner core. A guide having a synthetic resin coating having a substantially uniform outer diameter that covers the entire inner core, and the outer diameter of the metal being substantially equal to the outer diameter of the main body side inner core having the synthetic resin coating. wire. 2. The guide wire according to claim 1, wherein the metal of the high X-ray imaging part is formed of an annular member. 3. The guide wire according to claim 2, wherein the annular member is formed of a coil or a pipe. 4. An X-ray imaging part having a high X-ray imaging metal layer formed on the outer surface by plating or vapor deposition instead of a metal having a high X-ray imaging property. The guide wire according to claim 1, wherein: 5. The guidewire according to claim 1, wherein the distal inner core portion is tapered toward the distal end. 6. The guide wire according to claim 1, wherein said inner core is formed of a pseudoelastic alloy. 7. The guide wire according to claim 1, wherein the pseudoelastic alloy is a superelastic alloy. 8. At least a tip portion of the synthetic resin film,
The guide wire according to any one of claims 1 to 7, wherein a fine powdery X-ray contrast material is mixed.