JP2516444B2 - Guide wire for catheter - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a guide wire used for introducing a catheter to a required part of a human body for treatment or examination.

[Prior 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. .

Examples of such catheter guide wires include those disclosed in Japanese Patent Laid-Open Nos. 60-7862 and 60-63066. These guide wires have an inner core at least the tip of which is formed of a superelastic metal body,
Further, the entire inner core is covered 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.

Further, in JP-A-61-45775, a water-soluble polymer substance or a derivative thereof is covalently bonded to the surface of the guide wire to impart lubricity to the surface to improve the sliding property of the guide wire. Is disclosed.

[Problems to be Solved by the Present Invention] When inserting a catheter into a target site in the body, the catheter is advanced inside the blood vessel with the tip of the guide wire slightly protruding from the catheter. Before reaching the target site, there are multiple vascular bifurcations, more complicated vascular bifurcations, meandering, bending, and even vascular sites with cholesterol adhering to the inner surface. Pass these sites. In order to do so, the tip of the guide wire is brought into contact with the branch portion or the like, and the tip of the guide wire is moved in either direction. Then, when the tip of the guide wire moves toward the target member by this work, the insertion is further performed.
Therefore, the tip of the guide wire needs to be slidably moved on the blood vessel wall with very weak force, and
It is preferable that the distal end portion of the guide wire is flexible, and the portion that comes into contact with the blood vessel wall has a small frictional resistance when coming into contact with the blood vessel wall.

In this respect, the guide wire disclosed in the above-mentioned JP-A-61-45775 has a sufficient effect. However, since the water-soluble polymer or its derivative is covalently bonded to the entire outer surface of this guide wire, the frictional resistance between the inner surface of the catheter and the outer surface of the guide wire is extremely small. The operation for inserting the guide wire is performed by holding the part where the guide wire is out of the human body in hand, pushing it in, pulling it back in the opposite direction, and giving a twist,
Gloves are worn during operation. For this reason,
If the operation resistance is too low, the guide wire may be pushed in or pulled back more than expected, and the operation resistance may be poor because the resistance is too small.

Therefore, the purpose of the present invention is to have a certain degree of operation resistance, excessive pushing of the guide wire during operation,
Further, the present invention provides a guide wire for a catheter, which is less likely to be pulled back and has a sufficiently low frictional resistance in a portion in contact with a blood vessel wall, and which can be easily inserted into a target site.

[Means for Solving the Problems] The object to achieve the above object is to have a highly rigid main body portion and a flexible tip portion that is less rigid than the main body portion,
A guide wire for a catheter, wherein only the surface of the tip portion has a surface that exhibits lubricity when wet.

Further, what achieves the above-mentioned object is that the first linear body made of a highly rigid material forming the main body and the rigidity connected to the tip of the first linear body is low and the flexibility is high. A core material formed of a second linear body made of a material having the first linear resin body, and a first synthetic resin layer covering the outer surface of the first linear body,
A guide for a catheter having a second synthetic resin layer that covers the outer surface of the second linear body, and further, only the surface of the second synthetic resin layer is a surface that exhibits lubricity when wet. It is a wire.

It is preferable that the second synthetic resin layer is made of a material different from that of the first synthetic resin layer. Further, it is preferable that the first linear body is formed of stainless steel or piano wire. Furthermore, it is preferable that the second linear body is formed of a superelastic alloy. Further, it is preferable that a high X-ray contrast part made of a high X-ray contrast metal is provided at the tip of the second linear body. Further, it is preferable that the second linear body is gradually softened toward the tip. Furthermore, it is preferable that the first linear body and the second linear body are fixed by an annular member fitted to a joint surface between the first linear body and the second linear body. Further, it is preferable that the annular member fitted to the joining surface of the first linear body and the second linear body is made of a shape memory alloy.

Further, what achieves the above-mentioned object is to cover the entire inner core with an inner core integrally formed with a highly rigid main body portion and a flexible tip portion having lower rigidity than the main body portion. A guide wire for a catheter having a synthetic resin layer, wherein only the surface of the synthetic resin layer at the tip portion of the inner core is a surface exhibiting lubricity when wet.

It is preferable that a high X-ray contrast part made of a high X-ray contrast material is provided at the tip of the inner core. Furthermore, it is preferable that the inner core is formed of a superelastic metal. The lubricious surface is preferably formed by immobilizing a water-soluble polymer or its derivative.

Further, what achieves the above object is to provide a linear body having a tip and a main body, a tip synthetic resin layer provided on an outer surface of the tip of the linear body, and a surface of the tip synthetic resin layer. A guide wire for a catheter, which comprises a lubricious substance provided on the main body of the linear body and a synthetic resin layer of a main body having a relatively small frictional resistance provided on the outer surface of the main body of the linear body.

The catheter guide wire of the present invention will be described with reference to the embodiments shown in the drawings.

The catheter guide wire 1 of the present invention has a highly rigid main body portion 10 and a flexible tip portion 12 that is less rigid than the main body portion 10, and further only the surface of the tip portion 12 is lubricative when wet. Is a lubricious surface 7.

 Therefore, description will be made with reference to the embodiment shown in FIG.

The guide wire 1 of this embodiment includes a first linear body 2 which is made of a highly rigid material and which forms the body 10.
The core material formed of the second linear body 3 made of a flexible material and connected to the distal end of the linear body 2 and the outer surface of the first linear body 2 are covered. The first synthetic resin layer 8 and the second synthetic resin layer 5 that covers the outer surface of the second linear body 3, and the surface of the second synthetic resin layer 5 is
Has a lubricious surface.

More specifically, the first linear body 2 forms the main body of the core material, and the operation at the base end (hand side when using) of the first linear body 2 is used as the tip. Since it has a function of reliably transmitting, for that reason, a material with high rigidity,
For example, it is made of stainless steel, piano wire, or the like. As the rigidity, a bending rigidity of 19 Kg mm ² or more, more preferably 21 Kg mm ² or more, stainless steel or the like is suitable, and particularly high-tensile stainless steel for spring can be preferably used. The first linear body 2 has a diameter of 0.2 to 1.8 mm, preferably 0.3 to 1.6 mm, and a length of 200 mm to 3500 mm, preferably 300.
mm to 3000 mm.

The second linear body 3 forms a guide portion for advancing the guide wire in the meandering blood vessel and the thinned blood vessel, and therefore is formed of a highly flexible material, “Highly flexible” means a material having a wide elastic region that does not plastically deform even when a strain of 2 to 6% is applied.

Examples of such a wide elastic region include, for example, Ni
Superelastic materials such as -Ti alloys, Cu-Al-Ni alloys, and Cu-Zn-Al alloys are suitable. Specifically, the second linear body 3
As a Ti-Ni alloy of 49 to 58 atomic% Ni, a Cu-Zn alloy of 38.5 to 41.5 wt% Zn, a Cu-Zn-X alloy of 1 to 10 wt% X (X = Be, Si, Sn, Al , Ga), a superelastic metal body such as a Ni-Al alloy of 36 to 38 atomic% Al is preferably used. The above Ti-Ni alloy is particularly preferable. And the second linear body 3
Is preferably more flexible on the tip side, and in particular, is gradually softer toward the tip. Therefore, in the embodiment shown in FIG. 1, the second linear body 3 extends toward the tip. The diameter is gradually reduced, and the flexibility can be changed according to the adaptation by changing the diameter. The change in flexibility can also be made by changing the heat treatment conditions for the metal forming the second linear body. And the outer diameter of the second linear body 3 is 0.03 to 0.15.
mm, more preferably 0.05-0.10 and length 10-10
00 mm, preferably 50 to 5000 mm, particularly preferably 200 to 5
00 mm, bending load is 0.1-10 g, preferably 0.3-
6.0 g, restoration load is 0.1-10 g, preferably 0.3-6.0 g. Further, the outer diameter of the second linear body does not have to be the above-mentioned dimensions, and may be a part thereof.

Then, as shown in FIG. 1, a high X-ray contrast section 6 is preferably provided at the tip of the second linear body 3. The high X-ray contrast part can be formed by, for example, a metal annular member having a high X-ray contrast property fixed to the tip of the second linear body 3. Specifically, it is 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 6 is fixed by mechanical pressure bonding to the tip of the second linear body 3 or by soldering with a metal plated or vapor-deposited on the tip of the second linear body 3. Has been done. As the metal to be plated or vapor-deposited, when the second linear body 3 is a Ti-Ni alloy, Ni or the same kind as the high X-ray contrast metal to be used is suitable, such as Cu-Zn alloy or Cu. In the case of -Zn-X alloy, Zn or the same kind as the high X-ray contrasting metal used is suitable, and in the case of Ni-Al alloy, Ni or the high X-ray contrasting metal used. The same kind and the like are suitable. As the solder, a hard solder such as silver solder or gold solder can be preferably used.

When the high X-ray contrast part 6 is formed of an annular member, the outer diameter is 0.20 to 0.90 mm, preferably 0.25 to 0.40 mm,
Inner diameter 0.04 to 0.16 mm, preferably 0.06 to 0.11 mm, length
It is 1.00 to 10.0 mm, preferably 1.5 to 4.0 mm. Also,
The high X-ray contrast part 6 may be a coil formed by winding a thin wire made of a metal having high X-ray contrast property as described above at the tip of the second linear body 3. As this fine wire, a wire having a wire diameter of 0.02 to 0.10 mm is suitably used. The length that can be wrapped is 1.0 to 10.0 m from the tip of the inner core.
m, preferably 1.5 to 4.0 mm.

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. As another method, a high X
It is also possible to plate or vapor-deposit a metal for enhancing the adhesiveness to the line contrast part, and to attach the above-mentioned fine wire wound or coiled thereon and solder it.

Further, the high X-ray contrast part 6 is, in addition to the above-mentioned parts, applied and pressure-bonded with a high X-ray contrast metal foil on the tip of the inner core, and plating or vapor deposition of the high X-ray contrast metal on the tip. Alternatively, a high X-ray contrast metal layer may be formed. The above-mentioned metal foil, plating and vapor deposition preferably have a thickness of 50 μm or more.

And the connection between the first linear body 2 and the second linear body is
A method of fitting the base end portion of the second linear body 3 to the distal end portion of the first linear body 2, a method of brazing the both, and the like,
Alternatively, a combination of both can be used.
Particularly preferably, as shown in FIG. 1, the first linear body 2
Is fixed by an annular member 4 fitted on the joint surface of the second linear body 3 and, in particular, the annular member 4 is preferably formed of a shape memory alloy. Specifically, the shape in which the inner diameter of the annular member 6 has an outer diameter at the tip of the first linear body 2 and an inner diameter at the rear end of the second linear body that is slightly smaller than the outer diameter is memorized. , By expanding the inner diameter by forcibly expanding it, it is fitted to the joint part of the above-mentioned linear body and then heated or cooled to a predetermined temperature to restore the memorized shape. It is to use what you do. As the shape memory alloy, Ni-Ti alloy,
Shape memory alloys such as Cu-Al-Ni alloys and Cu-Zn-Al alloys are suitable. Specifically, as the second linear body 3,
49-58 atom% Ni Ti-Ni alloy, 38.5-41.5 wt% Zn Cu
-Zn alloy, 1-10 wt% X Cu-Zn-X alloy (X = Be, S
i, Sn, Al, Ga), and a Ni-Al alloy containing 36 to 38 atomic% Al are preferably used.

Further, it is preferable to provide a synthetic resin layer 8 on the outer surface of the first linear body 2 in order to reduce the frictional resistance with the inner surface of the tubular body such as a catheter to some extent. As the synthetic resin layer 8, polyethylene, polyvinyl chloride, polyester, polypropylene, polyamide, polyurethane, polystyrene, fluororesin (for example, PTFE, ETFE), silicone rubber or their respective elastomers and composite materials are preferably used. Preferred is a fluororesin. The synthetic resin layer 8 is preferably flexible enough not to hinder the bending of the inner core 2, and the outer surface is preferably a smooth surface without unevenness. The synthetic resin layer 8 is coated with an anticoagulant such as heparin or urokinase, or an antithrombotic material such as silicone rubber, urethane / silicone block copolymer (registered trademark Abucosan), or hydroxyethyl methacrylate-styrene copolymer. You may. Particularly preferably, the synthetic resin layer 8 is formed of a resin having a low friction surface such as fluororesin. The thickness of the synthetic resin layer 8 is 0.25 to 1.04 mm, preferably 0.30 to 0.64 mm.

Further, it is necessary to provide the synthetic resin layer 5 on the outer surface of the second linear body 3. As the synthetic resin layer 5, polyethylene, polyvinyl chloride, polyester, polypropylene, polyamide, polyurethane, polystyrene, fluororesin (for example, ETFE), silicone rubber, respective elastomers and composite materials are used. And
In particular, polyvinyl chloride, polyurethane, and polyester are examples of synthetic resins having a high effect of fixing a lubricating substance when forming a lubricating surface described later, in other words, having a high lubricating effect. Further, when using a synthetic resin other than these synthetic resins, it is preferable to use a mixture of the above synthetic resins with the synthetic resin.

The synthetic resin layer 5 is preferably flexible enough not to hinder the bending of the inner core 2, and the outer surface is preferably a smooth surface without unevenness. Furthermore, the synthetic resin layer 5
It is preferable to mix an X-ray contrast medium in the form of a fine powder with a simple metal or compound such as Ba, W, Bi, Pb, etc. into the synthetic resin that forms the resin. It becomes easy to confirm the position of the distal end portion of the guide wire 1.

The surface of the synthetic resin layer 5 needs to be a lubricious surface, and the lubricious surface is preferably formed by fixing a lubricating substance on the surface of the synthetic resin layer 5.

Lubricant refers to a substance that has lubricity when wet. Specifically, there are water-soluble polymer substances or their derivatives. The lubricating substance is fixed to the surface of the synthetic resin by covalent bond or ionic bond. Then, the lubricant material is a polymeric material having no crosslinked principle _{chain, -OH, -CONH 2, -COOH,} -NH 2, -COO -, -SO 3-
It has a hydrophilic group such as. In addition, the lubricious substance is
When wet (for example, in contact with blood), it contains water and exhibits lubricity.

By fixing such a lubricating substance to the synthetic resin layer 5, which is the outer surface of the guide wire 1, the friction between the inner wall of the catheter and the outer surface of the guide wire is reduced when the catheter is introduced, and the guide wire slides inside the catheter. Since the mobility is improved, the guide wire can be easily operated.

Specific examples of the natural water-soluble polymer substance include starch-based materials such as carboxymethyl starch, cellulose-based materials such as carboxymethyl cellulose, polysaccharides such as alginic acid, heparin, chitin and chitosan, and proteins such as gelatin. As the synthetic water-soluble polymer substance, polyvinyl alcohol, polyalkylene oxide-based polyethylene oxide, polyalkylene glycol-based polyethylene glycol,
Acrylic acid-based, polyacrylic acid soda, maleic anhydride-based, methyl vinyl ether maleic anhydride copolymer, methyl vinyl ether sodium maleic anhydride, methyl vinyl ether maleic anhydride ammonium salt, maleic anhydride ethyl ester copolymer, phthalate Acid-based, polyhydroxyethyl phthalate ester, water-soluble polyester, polydimethylol propionate, acrylamide-based polyacrylamide hydrolyzate, polyacrylamide quaternized product, polyvinylpyrrolidone, polyethyleneimine, polyethylenesulfonate, water-soluble nylon And so on. 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 above water-soluble polymer substance, addition, substitution, oxidation,
Esterification products, salts, amidation products, anhydrides, halides, etherification products, hydrolysis products, acetalization products, formalization products, alkylol products, quaternary products, diazo compounds, hydrazide products, sulfonation products obtained by reduction reaction, etc. Nitrates, ion complexes, further diazonium groups, azido groups, isocyanate groups, acid chloride groups, acid anhydride groups, iminocarbonic acid ester groups, amino groups,
Crosslinked product with a substance having two or more reactive functional groups such as carboxyl group, epoxy group, hydroxyl group and aldehyde group, and copolymerization with vinyl compound, acrylic acid, methacrylic acid, diene compound, maleic anhydride, etc. Things can be considered.

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. .

A reactive functional group present or introduced into the synthetic resin,
By bonding with the above-mentioned lubricating substance, lubricating properties can be provided on the synthetic resin surface, and a continuous lubricating surface can be obtained without being dissolved in water. 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, etc. are preferably used. Especially hydroxypropyl cellulose, methyl vinyl ether,
Maleic anhydride copolymer, polyacrylamide, polyethylene glycol, water-soluble nylon (manufactured by Toray Industries, Inc.
AQ-nylon P-70) is suitable. Although the average molecular weight of these lubricating substances is not particularly limited, 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 which is not extremely large. It is.

Further, as the lubricating substance fixed to the surface of the synthetic resin by ionic bonding, in addition to polyvinylpyrrolidone, carboxylate, sulfonate,
There are ammonium salts and the like, and specific examples of the carboxylic acid salts include sodium salts of methyl vinyl ether maleic anhydride, sodium polyacrylate, hydrolysates of polyacrylamide, sodium carboxymethyl cellulose, sodium alginate, and the like, and sulfonate salts. Include sodium polystyrene sulfonate, sodium polyvinyl sulfonate, and the like, and examples of the ammonium salt include an ammonium salt of methyl vinyl ether maleic anhydride, a quaternary polyacrylic acid, and the like.

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 or the like. A 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, and an isocyanate group, an amino group, an aldehyde group and an epoxy group are particularly preferable.

Therefore, as the synthetic resin having a reactive functional group, polyurethane, polyamide and the like are preferable.

Further, as the substance having a reactive functional group, for example,
Isocyanates such as methylene diisocyanate and ethylene diisocyanate, and adducts or prepolymers of these isocyanates and polyols, and further, for example, ethylenediamine as a low molecular weight polyamine,
Trimethylenediamine, 1.2-diaminopropane, tetramethylenediamine, etc. are considered. As a high molecular weight polyamine, poly (alkylene polyamine) synthesized from [I] amine and alkylene dihalide or epichlorohydrin, [II] alkylene imine polymer obtained by ring-opening polymerization of alkylene imine such as ethylene imine, [III] others, There are polyamines such as polyvinylamine, polyaldehydes such as glutaraldehyde, and polyepoxides such as ethylene glycol diglycidyl ether.

Next, an embodiment of the guide wire for catheter of the present invention shown in FIG. 2 will be described.

The guide wire 1 of this embodiment has a highly rigid body portion.
An inner core 22 integrally formed with a tip portion 12 having a rigidity lower than that of the main body 10 and having flexibility, and a synthetic resin layer 25 covering the entire inner core 22. Only the surface of the synthetic resin layer 25 at the tip 12 is a lubricious surface 27 that exhibits lubricity when wet.

More specifically, the inner core 22 of the guide wire 1 has a main body portion 22a and a distal end portion 22b, and is integrally formed of superelastic metal. Then, the tip portion 22b is the main body 2
The diameter is gradually reduced from the tip of 2a toward the tip. By having such a small diameter, the rigidity is lower than that of the main body. Thus, by gradually reducing the diameter of the tip of the inner core, when a force is applied to the tip, the tip bends gradually, so that the operability is improved.
As the inner core 22, 49-58 atomic% Ni Ti-Ni alloy, 38.5-
41.5 wt% Cu-Zn alloy, 1-10 wt% X Cu-Zn-
X alloy (X = Be, Si, Sn, Al, Ga), 36-38 atomic% Al Ni-
A super elastic metal body such as an Al alloy is preferably used. The above Ti-Ni alloy is particularly preferable. The outer diameter of the main body portion 22a of the inner core 22 is 0.10 to 1.00 mm, more preferably 0.15.
~ 0.40 mm, length 1000 ~ 4000 mm, more preferably 1500 ~ 3000 mm, buckling strength (yield stress under load) is 30
~ 100Kg / mm ² (22 ° C), more preferably 40-55Kg / mm ² ,
The restoring stress (yield stress at unloading) is 20 to 80 kg / mm ² (22
C.), more preferably 30 to 35 Kg / mm ² .

The outer diameter of the tip portion 22b of the inner core 22 is 0.03 to 0.15 mm,
More preferably, it is 0.05-0.10 and the length is 10-300 m.
m, preferably 50-150 mm, bending load 0.1-10
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.

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 22 is not limited to one formed by a single wire, and may be a plurality of wires that are parallel or twisted, and exhibit the above-mentioned function, that is, a stepwise or continuous change in physical properties.

Further, it is preferable to have a high X-ray contrast part 6 at the tip of the inner core 22, and in the embodiment shown in FIG. 2, a metal annular member having a high X-ray contrast property fixed to the tip of the inner core 22 is used. It is installed. Specifically, a thin wire made of a metal having high X-ray contrast as described above is wound around the tip of the inner core 22 in a coil shape. The diameter of this thin wire is
Those having a thickness of 0.02 to 0.10 mm are preferably used. Also, the length of wrapping around is 1.0 to 10.0 mm, preferably 1.5 to 4.0 mm from the tip of the inner core. 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. As another method, a metal for enhancing the adhesiveness with the high X-ray contrast part is plated or vapor-deposited on the tip of the inner core, and the thin wire is wound or coiled on the metal. ,
It may be done by soldering.

Further, the high X-ray contrast part 3 is, in addition to the above-described one, applied and pressure-bonded with a high X-ray contrast metal foil on the tip of the inner core, and plated or vapor-deposited the high X-ray contrast metal on the tip. Alternatively, a high X-ray contrast metal layer may be formed. The above-mentioned metal foil, plating and vapor deposition preferably have a thickness of 50 μm or more.

Further, the synthetic resin layer 25 covering the entire inner core 22 is the first
As shown in the figure, it has a substantially uniform outer diameter including the tip. Particularly, in the synthetic resin layer 25, a step due to a high X-ray contrast part provided at the tip of the inner core 22 is
Has a substantially uniform outer diameter so as not to affect the outer surface shape. As the synthetic resin layer 25, polyethylene, polyvinyl chloride, polyester, polypropylene, polyamide, polyurethane, polystyrene, fluororesin, silicone rubber, respective elastomers and composite materials are preferably used. Then, the synthetic resin layer 25 is the inner core 22.
It is preferable that the outer surface is a flexible surface that does not hinder the curvature of the surface and the outer surface is a smooth surface with no unevenness.

Further, in the synthetic resin forming the synthetic resin layer 25, Ba,
It is preferable to mix a fine powdery X-ray contrast substance with a simple metal or compound such as W, Bi, Pb, etc. By doing so, it is easy to confirm the entire position of the guide wire 1 being introduced into the blood vessel. Becomes As described above, the synthetic resin layer 25 has a substantially uniform outer diameter. Almost uniform means
The tip is not limited to a completely uniform one, and the tip may have a small diameter. 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 thickness of the inner core 22 of the synthetic resin layer on the main body portion 22a is 0.25.
˜1.04 mm, preferably 0.30 to 0.64 mm.

Further, it is preferable that the synthetic resin layer 25 is adhered to the inner core 22 by a synthetic resin in a close contact state, and is also fixed to the front end portion and the base end portion of the inner core 22. Alternatively, the synthetic resin layer 25 may be formed of a hollow tube, and may be fixed to the inner core 22 by adhesion or melt molding at the distal end portion and the proximal end portion of the inner core 22 or at an appropriate portion of the inner core. The tip of the guide wire 1 (tip of the synthetic resin layer 25) has a hemispherical curved surface as shown in FIG. 1 in order to prevent damage to the blood vessel wall and improve the operability of the guide wire 1. Preferably.

And, as the synthetic resin layer forming the synthetic resin layer 25, it is preferable to use a synthetic resin having a high lubricating effect when fixing the lubricating surface 27, which will be described later. Specifically, polyvinyl chloride, polyurethane, polyester and the like are preferable. When using a synthetic resin other than these synthetic resins,
It is preferable to use a mixture of the above synthetic resin with the synthetic resin. Further, for the synthetic resin layer 25, the synthetic resin of different materials may be used for the portion of the inner core 22 that covers the tip portion 22b and the portion that covers the main body portion 22a. In this case, as the portion that covers the tip portion 22b, a synthetic resin having a high effect of fixing the above-mentioned lubricating substance is used, and as the synthetic resin that covers the main body portion 22a, the friction resistance is relatively small, polyethylene, It is preferable to use polypropylene, polyamide, fluororesin (eg, PTFE, ETFE), or the like.

The surface of the tip of the inner core of the synthetic resin layer 25 is a lubricious surface 27. The lubricating surface is preferably formed by fixing a lubricating substance on the surface of the synthetic resin layer at the tip portion of the inner core. Lubricant refers to a substance that has lubricity when wet. The above-mentioned substances can be preferably used as the lubricating substance.

Further, the synthetic resin layer 25 of the main body portion 22a of the inner core 2 includes an anticoagulant such as heparin and urokinase, or silicone rubber, urethane and silicone block copolymer (registered trademark Abucosan), hydroxyethyl methacrylate-styrene copolymer. An antithrombotic material such as a polymer may be coated.

[Example] Next, an example of the guidewire of the present invention will be described.

The first linear body that forms the main body is made of stainless steel (SUS304, 18Cr steel) and has an outer diameter of 0.41 mm and a length.
The length was 1500 mm, and the tip part had a length of 10 mm and a small diameter part with an outer diameter of 0.3 mm. Then, the outer surface of the first linear body was baked and coated with PTFE. The second linear body forming the tip portion was made using a Ni-Ti alloy (52 atomic% Ni), and the outer diameter of the base end portion (portion joined to the first linear body) was , 0.3 mm, the diameter was reduced toward the tip, the outer diameter of the tip was 0.07 mm, and the length was 300 mm. First
As a tubular member for joining the linear body of and the second linear body,
Shape memory alloy pipe (Ni-Ti alloy, 52 atom% Ni) is used, shape restoration temperature 80 ℃, inner diameter 0.20mm, outer diameter 0.40mm when restored, this shape memory alloy pipe Was used forcibly, and the inner diameter was expanded to 0.30 mm.

Then, after joining the end portions of the first linear body and the second linear body, respectively, the shape memory alloy pipe is fitted to the joint portion, and the pipes are heated by using a heat gun to form the memory shape. The two linear bodies were joined to each other by restoring the two.
Subsequently, a pipe-shaped member formed of pure gold with an inner diameter of 0.08 mm, an outer diameter of 0.30 mm, and a length of 2 mm was created, inserted into the tip of the second linear body, and sandwiched with a jig to form a second piece. Then, the high X-ray contrast part was formed by pressure-bonding and fixing to the linear body.

 Furthermore, a fine tungsten powder is formed on the outer surface of the second linear body.
Polyurethane containing 45% by weight (particle size of about 3-4 μm)
(Pandex (T-5000, made by Dainippon Ink Co., Ltd.)
Was coated to form a synthetic resin layer. In addition, tetrahydr
Ethane maleic anhydride should be 2.0% by weight in lofran.
The solution in which the polyester ester copolymer was dissolved
Applied to the surface of the synthetic resin layer formed of
Immobilize maleic acid ethyl ester copolymer, lubricity
The surface was formed.

This guide wire has an overall length of about 1800 mm, a bending load of about 0.2 g at the tip of the guide wire, and a restoring load of about
It was 0.1 g. Also, when the body was cut to a length of 50 mm, one end was fixed like a cantilever burr and the other was pressed horizontally, and the other end was pressed 5 mm, the bending rigidity was measured and found to be 10 g. It was When the X-ray imaging of the entire guide wire created in this way was performed, a high X-ray contrast image was obtained at the tip.

[Operation] Next, the operation of the guide wire for a catheter of the present invention will be described using the embodiment shown in FIG.

The guide wire 1 of the present invention is used for guiding a catheter such as an angiography catheter or a blood vessel dilatation catheter into a target site of a blood vessel. When inserting the guide wire 1, First, after securing a blood vessel in the human body by the Seldinger method or the like, the catheter guide wire 1 of the present invention is placed in the blood vessel,
A catheter is inserted into the blood vessel along it. In this insertion, the catheter guide wire 1 is inserted into the blood vessel in a state in which the catheter guide wire 1 is projected by several cm (the coil spring 4 portion). And the tip 12
Uses a linear body formed of a flexible material, the tip 12 is sufficiently flexible and can be easily inserted into a meandering blood vessel or a narrowed blood vessel. further,
Since the outer surface of the tip portion 12 is the lubricious surface 7, the frictional resistance when contacting the blood vessel wall is extremely small, and the guide wire 1 can be easily guided to the target site.
Further, the main body portion 10 is formed of a material having high bending rigidity, and when the tip portion 12 is pushed in when the tip of the guide wire 1 is operated to travel in a desired direction within a lumen such as a blood vessel. In addition, the force of the operation at the proximal end (hand) of the guide wire performed when rotating it can be reliably transmitted to the distal end 12 for easy insertion, and further, the outer surface of the main body 10 Since it does not have a lubricious surface, it has some operating resistance. Therefore, there is little possibility of pushing and pulling back the guide wire excessively due to the operation resistance being too low, and the operability is excellent. Then, after the tip of the catheter has been guided to the vicinity of the target site, the guide wire 1 is withdrawn, and if the catheter is an angiography catheter, an angiography agent is injected from the rear end to perform X-ray imaging, To remove the pressure, stop the bleeding with pressure and finish the procedure.

[Effects of the Invention] The catheter guide wire of the present invention has a highly rigid body portion and a flexible tip portion that is less rigid than the body portion, and only the outer surface of the tip portion is lubricated when wet. Since the tip has a lower rigidity than the main body, the tip is sufficiently flexible and can be easily inserted into a meandering blood vessel or a narrowed blood vessel. Furthermore, since the outer surface of the tip is a lubricious surface,
Frictional resistance when contacting the blood vessel wall is extremely small, and it is easy to guide the tip to the target site. Also, since the main body has a high bending rigidity, it is performed when operating the tip of the guide wire in the desired direction within the lumen such as a blood vessel, when pushing in the tip, or when rotating it. The force of the operation at the proximal end (hand) of the guide wire can be reliably transmitted to the distal end and insertion can be done easily. Furthermore, the outer surface of this main body is not a lubricious surface, It has some operating resistance. Therefore, there is little possibility of pushing and pulling back the guide wire excessively due to the operation resistance being too low, and the operability is excellent.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the catheter guide wire of the present invention, and FIG. 2 is a sectional view showing another embodiment of the catheter guide wire of the present invention. 1 ... Catheter guide wire 2 ... First linear body, 3 ... Second linear body, 4 ... Annular member, 5 ... First synthetic resin layer, 6 ... High X-ray contrast Part, 7 ... Lubricating surface, 8 ... Second synthetic resin layer, 10 ... Main body part, 12 ... Tip part

Claims (4)

(57) [Claims] 1. A main body having a high rigidity and a flexible tip having a rigidity lower than that of the main body, and only the surface of the tip is a surface exhibiting lubricity when wet. Guide wire for catheter. 2. A first linear body made of a highly rigid material for forming a main body, and a low-rigidity and flexible material connected to a tip portion of the first linear body. A core material formed of two linear bodies, a first synthetic resin layer that covers the outer surface of the first linear body, and a second synthetic resin layer that covers the outer surface of the second linear body. A guide wire for a catheter, comprising a resin layer, and wherein only the surface of the second synthetic resin layer is a surface exhibiting lubricity when wet. 3. An inner core integrally formed with a highly rigid main body portion, a flexible tip portion having lower rigidity than the main body portion, and a synthetic resin layer covering the entire inner core portion. A guide wire for a catheter, characterized in that only the surface of the synthetic resin layer at the distal end portion of the inner core is a surface exhibiting lubricity when wet. 4. A linear body having a tip and a body, a tip synthetic resin layer provided on the outer surface of the tip of the linear body, and lubrication provided on the surface of the tip synthetic resin layer. A guide wire for a catheter, comprising a conductive substance and a main body synthetic resin layer having a relatively small frictional resistance provided on the outer surface of the main body of the distal end portion.