JP4417355B2 - Medical wire - Google Patents

Description

  The present invention relates to a medical wire used for introducing a catheter into a necessary part of a human body for treatment or examination.

  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 tip of the guide wire is slightly protruded from the tip 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, a coil having a high X-ray contrast function is fixed to the end of a thin metal core, and the whole is covered with a resin containing about 30 to 40% by weight of an X-ray opaque material. There is something that was done.
JP-A-8-257133

Such a guide wire has high flexibility due to the reduced diameter of the distal end portion, and further has high X-ray contrast properties, so that the catheter can be easily introduced into the target site. it can.
Recently, for example, guide wires for PTCA, cerebral blood vessels, and liver blood vessels are required to have thinner tips and more flexibility. However, in the above-described conventional guide wire, a coil having a high X-ray contrast function is fixed to the distal end portion of the core wire, and therefore the core wire distal end portion is required to have a minimum thickness capable of fixing the coil. Therefore, although it has an excellent effect in terms of visibility under X-ray fluoroscopy, there is a limit to the flexibility of the tip due to the presence of the coil and the thickness of the tip.
Further, as a guide wire not using a coil, for example, there is one shown in Japanese Patent Laid-Open No. 8-257133 (Patent Document 1). This is a resin film containing a radiopaque substance at a high concentration at the tip, but the amount of X-ray contrast agent that can be added to the resin is limited from the viewpoint of adhesion of the resin to the core wire. The X-ray contrast function is not so high. Note that “the content of the radiopaque material is 40 to 200 wt%” in JP-A-8-257133 is the weight of the radiopaque material when the resin weight before the radiopaque material is mixed is 100. The calculation method differs from the content in the present invention ((X-ray opaque material weight / total resin weight after mixing) × 100) which cannot exceed 100% by weight. If the calculation method in this invention is used, content in the said gazette will be "28.6-66.7 weight%."

  Accordingly, an object of the present invention is to provide a medical wire having a distal end portion with sufficient flexibility and high X-ray contrast properties.

What achieves the above-described object is to provide a main body having high rigidity, an inner core integrally formed with a tip having a smaller diameter and lower rigidity than the main body, and a synthetic resin covering the tip of the inner core. A distal end portion of the inner core is provided with a plate-like portion formed in a thin plate shape, and the synthetic resin coating is an upper layer and has an X-ray resistance of 70% by weight or more. A first synthetic resin layer formed of a synthetic resin containing a permeable substance; a second synthetic resin layer positioned between the first synthetic resin layer and a tip of the inner core; and The synthetic resin forming the synthetic resin layer is a resin having a higher rigidity than the first synthetic resin and has a content lower than the content of the radiopaque material in the first synthetic resin layer. A resin that contains a radiopaque material, and further comprises a resin and a resin that form the first synthetic resin layer. The resins forming the second synthetic resin layer may be either polyamide resins, both polyolefin resins, both urethane resins, both polyester resins, or both vinyl chloride resins. This is a medical wire.
The content of the radiopaque material in the second synthetic resin is preferably 45% by weight or less.

In addition, what achieves the above-described object is to cover a core part having a high rigidity, an inner core formed integrally with a tip part having a smaller diameter and lower rigidity than the main body part, and the tip part of the inner core. A medical wire provided with a synthetic resin coating, wherein a tip portion of the inner core includes a plate-like portion formed in a thin plate shape, and the synthetic resin coating is an upper layer and 70 wt% or more of X A first synthetic resin layer formed of a synthetic resin containing a radiopaque material, and a second synthetic resin layer located between the first synthetic resin layer and the tip of the inner core, The synthetic resin forming the second synthetic resin layer is a resin having higher rigidity than the first synthetic resin and does not contain an X-ray opaque material, and further includes the first synthetic resin layer. Both the resin to be formed and the resin to form the second synthetic resin layer are both poly Bromide based resin, both a medical wire is either together polyolefin resin, both together urethane resin, both together polyester resin, both together a vinyl chloride resin.

  In the medical wire described above, the width of the plate-like portion is wider than the outer diameter of the inner core of the portion continuous with the plate-like portion, and the thickness of the plate-like portion is continuous with the plate-like portion. It is preferable that it is thinner than the outer diameter of the inner core of the part to perform. The synthetic resin preferably contains 70 to 85% by weight of an X-ray opaque material. Furthermore, it is preferable that the front-end | tip part of the said inner core is equipped with the taper part diameter-reduced toward the front-end | tip formed in the base end side from the plate-shaped part, and the linear part continuous with this taper part. In particular, the distal end portion of the inner core has a first linear portion formed on the proximal side from the plate-shaped portion, and a first taper that is continuous with the first linear portion and decreases in diameter toward the distal end. And a second linear portion that is continuous with the first tapered portion, and a second tapered portion that is continuous with the second linear portion and has a diameter reduced toward the tip. .

The medical wire of the present invention includes a main body portion having high rigidity, an inner core integrally formed with a tip portion having a smaller diameter and lower rigidity than the main body portion, and a synthetic resin that covers the tip portion of the inner core. A distal end portion of the inner core includes a plate-like portion formed in a thin plate shape, and the synthetic resin coating contains 70% by weight or more of an X-ray opaque material. It is formed of a synthetic resin.
For this reason, compared with the medical wire which arranged the X-ray impermeable substance coil etc. in the conventional tip part, since the flexibility of a tip part is high, and grasping of the position of the tip under X-ray contrast can also be performed reliably, The introduction work of the medical wire can be easily performed.
Further, the width of the plate-like portion is wider than the outer diameter of the inner core of the portion continuous with the plate-like portion, and the thickness of the plate-like portion is outside the inner core of the portion continuous with the plate-like portion. By making it thinner than the diameter, the surface area of the tip of the inner core is increased, the contact area with the resin coating is increased, the adhesion and retention of the resin coating is ensured, and the peel resistance of the resin coating 3 is improved.

Further, the ultrasonic catheter of the present invention is an ultrasonic catheter including an ultrasonic transducer housed inside the distal end portion and a guiding portion that forms the distal end, and the guiding portion includes a highly rigid main body portion, The inner core is integrally formed with a tip having a smaller diameter and lower rigidity than the main body, and a synthetic resin film covering the tip of the inner core. A thin plate-like plate-like portion is provided, and the synthetic resin film is made of a synthetic resin containing 70% by weight or more of an X-ray opaque material.
For this reason, compared with an ultrasonic wire in which an X-ray impermeable material coil or the like is arranged in the guiding portion, the tip portion is highly flexible and the position of the tip under X-ray contrast can be reliably grasped. Wire introduction work can be easily performed.

Moreover, the catheter with an expansion body of this invention is a catheter with an expansion body provided with the expandable expansion body provided in the front-end | tip part, the lumen for fluid distribution for expanding this expansion body, and the guidance | induction part which forms a front-end | tip. The guide portion includes a main body portion having high rigidity, an inner core integrally formed with a tip portion having a smaller diameter and lower rigidity than the main body portion, and a synthetic covering the tip portion of the inner core. A synthetic resin containing a X-ray opaque material in an amount of 70% by weight or more, and the tip of the inner core has a plate-like portion formed in a thin plate shape. It is formed by.
For this reason, compared with a catheter with an expansion body in which an X-ray impermeable material coil or the like is arranged in the guiding portion, the distal end portion is more flexible and the position of the distal end under X-ray contrast can be reliably grasped. It is possible to easily introduce the body-attached catheter into the blood vessel stenosis portion or the like.

The method for producing a medical wire according to the present invention includes a step of preparing an inner core, a powder of a thermoplastic synthetic resin and a powder of an X-ray opaque material, and 70 wt% or more of X-ray opaqueness. Producing a synthetic resin mixture containing the substance, heating and melting the synthetic resin mixture to produce a pellet containing a high amount of X-ray-impermeable substance, and at least a tip portion of the inner core and the thermoplastic synthetic resin A step of forming a resin film containing a soluble thermoplastic resin, and a high X-ray opaque substance-containing resin film is formed by heating and melting the X-ray opaque substance-containing pellet on the resin film. Process.
For this reason, it is possible to form a resin film containing a high amount of X-ray opaque material that does not easily peel or detach from the distal end portion of the inner core, and a medical wire having high X-ray contrast properties at the distal end portion can be easily and reliably formed. Can be manufactured.

Next, an embodiment of the medical wire of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional view of an embodiment in which the medical wire of the present invention is applied to a guide wire. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is an enlarged cross-sectional view of the distal end portion of the guide wire 1 shown in FIG. FIG. 4 is an enlarged cross-sectional view of the distal end portion of the guide wire shown in FIG. FIG. 5 is an external view of the inner core. FIG. 6 is an enlarged perspective view of the distal end portion of the inner core.

  The medical wire 1 of the present invention includes an inner core 2 in which a main body 2a having high rigidity and a tip 2b having a smaller diameter and lower rigidity than the main body 2a are integrally formed, and a tip 2b of the inner core 2. And a synthetic resin film 3 for covering the film. And the front-end | tip part 2b of the inner core 2 is equipped with the plate-shaped part 4 formed in thin plate shape, and the synthetic resin film 3 is formed of the synthetic resin containing 70 weight% or more X-ray opaque substance. .

An embodiment in which the medical wire of the present invention is applied to a guide wire will be described with reference to FIGS.
The guide wire 1 covers an inner core 2 in which a main body portion 2a having high rigidity and a tip portion 2b having a smaller diameter and lower rigidity than the main body portion 2a are integrally formed, and the front end portion 2b of the inner core 2. And a synthetic resin coating 3.

  The inner core 2 has a main body portion 2a and a tip portion 2b and is integrally formed. As shown in FIGS. 1 to 5, the distal end portion 2b is formed so that its diameter gradually decreases from the distal end of the main body portion 2a toward the distal end, and the rigidity of the distal end portion 2b is lower than that of the main body portion 2a. It is said that. In this manner, by gradually reducing the diameter of the tip 2b of the inner core 2, the tip 2b is gradually bent when a force is applied to the tip, so that the operability is improved.

  The distal end portion 2b of the inner core 2 used in the guide wire of this embodiment has a plate-like portion 4, a first straight portion 21a continuous with the plate-like portion 4, and a continuous straight portion 21a. The taper part 21b which reduces in diameter toward the front-end | tip is provided. In particular, in the embodiment shown in FIGS. 1 to 5, as shown in FIG. 5, the distal end portion 2 b of the inner core 2 is formed on the base end side from the plate-like portion 4 and is continuous with the plate-like portion 4. The first linear portion 21a, the first linear portion 21a that is continuous with the first linear portion 21a, the first tapered portion 21b that is reduced in diameter toward the tip, the second linear portion 22a that is continuous with the first tapered portion 21b, A second taper portion 22b that is continuous with the second straight portion 22a and is reduced in diameter toward the tip, a third straight portion 23a that is continuous with the second taper portion 22b, and a third straight portion 23a. A third taper portion 23b that is continuous and has a diameter reduced toward the tip is provided. In addition, the part (1st linear part) which continues with the plate-shaped part 4 does not become a linear part like the Example mentioned above, but may be a taper part.

  In this way, instead of reducing the diameter by a uniform taper, by repeatedly providing a tapered portion and a linear portion and reducing the diameter stepwise, a portion having a constant rigidity is formed, so that a body cavity such as a heart is formed. In accordance with the curved shape, it becomes easy to form a relatively long flexible portion without a sudden change in physical properties.

  A plate-like portion 4 is formed at the tip of the inner core 2. The plate-like portion 4 is formed by crushing (rolling) the first straight portion 21a. As a result, as shown in FIG. 6, the thickness of the plate-like portion 4 is as follows. As shown in FIG. 3, the width is thinner than the outer diameter of the straight portion 21a that is continuous with 4, and wider than the outer diameter of the straight portion 21a. Thus, by making the front end of the inner core 2 into a flat plate shape, the front end of the inner core 2 becomes more flexible. And by providing this flat plate part, the surface area of the front-end | tip of the inner core 2 becomes large, the contact area with the resin film 3 increases, the adhesion retention of the resin film 3 is ensured, and the peeling resistance of the resin film 3 is improved. improves. Although the surface area is reduced, the tip may be plate-shaped as described above, and etching may be performed to make the width equal to the outer diameter of the straight portion (portion continuous with the plate-shaped portion). . By doing in this way, the front-end | tip of the inner core 2 can be made more flexible.

As the inner core 2, stainless steel is preferably used. The outer diameter of the main body 2a of the inner core 2 is 0.2 to 0.51 mm, preferably 0.23 to 0.46 mm, and the length is 200 to 3000 mm, preferably 400 to 2600 mm. It is. Further, the buckling strength of the body portion 2a (yield stress under load) is 500~1200g / mm ^2, preferably a 700~900g / mm ^2.

  Moreover, the length of the front-end | tip part 2b of the inner core 2 is 20-600 mm, Preferably, it is 30-500 mm. Further, the minimum outer diameter (excluding the plate-like portion 4) of the distal end portion 2b of the inner core 2 is 40 to 300 μm, preferably 50 to 250 μm. The length of the plate-like portion 4 is 5 to 50 mm, preferably 10 to 30 mm, the thickness is 15 to 120 μm, preferably 20 to 90 μm, and the width is 45 to 45 mm. It is 380 micrometers, Preferably, it is 55-300 micrometers.

  Further, the plate-like portion 4 is not limited to the flat plate shape as described above, and the cross-section is elliptical, and conversely, the upper surface or the lower surface of the plate-like portion 4 or both are concave. It may be the one that became.

  Furthermore, as shown in FIG. 7, the plate-like portion 4 may be thinner toward the tip. In this way, the tip can be made more flexible. In this case, when the plate-like portion 4 is formed by crushing (rolling) a portion having the same outer diameter, the width becomes wider toward the tip as shown in FIG. In this case as well, etching may be performed so that the width is the same as the outer diameter of the straight portion (portion continuous with the plate-like portion). By doing in this way, the front-end | tip of the inner core 2 can be made more flexible.

  Further, the dimensions of the main body 2a, the tip 2b, and the plate-like part 4 of the inner core 2 are not necessarily the above-mentioned dimensions, and may be a part. Further, the buckling strength and the restoring stress of the main body 2a need not all have the same value, and may be devised so as to obtain appropriate physical properties at an appropriate wire diameter by changing them according to heat treatment conditions. That is, the heat treatment may be performed separately so that the main body 2a has a large restoring stress on the proximal end side and is flexible on the distal end side. Similarly, in the main body 2a and the front end 2b, the main body 2a may be subjected to heat treatment separately so that the restoring stress is large and the front end 2b is flexible.

  And the front-end | tip part 2b of the inner core 2 is coat | covered with the synthetic resin. In this embodiment, the synthetic resin coating 3 is an upper layer, and a first synthetic resin layer 3a formed of a synthetic resin containing 70% by weight or more of an X-ray opaque material, and the first synthetic resin. A layer 3a and a second synthetic resin layer 3b located between the tips of the inner core 2 are provided.

  The synthetic resin used for the first synthetic resin layer 3a is preferably a thermoplastic resin, and is an olefin resin such as polyethylene, polypropylene, polybutene, or ethylene-vinyl acetate copolymer, or a polyolefin elastomer, fluorine resin or the like. Polyester such as soft fluororesin, polyethylene terephthalate, polybutylene terephthalate or polyester elastomer, methacrylic resin, polyphenylene oxide, modified polyphenylene ether, polyurethane or polyurethane elastomer, polyamide or polyamide elastomer, polycarbonate, polyacetal, polystyrene, styrene butadiene copolymer Styrenic resin such as coalescence or styrene elastomer, thermoplastic polyimide, Such as vinyl chloride can be used. It is also possible to use polymer alloys or polymer blends based on these resins. Furthermore, rubbers such as natural rubber, isoprene rubber and silicon rubber can be used. In particular, a thermoplastic resin is suitable. The synthetic resin coating 3 is preferably flexible to the extent that the bending of the inner core 2 is not hindered, and the outer surface is preferably a smooth surface without irregularities.

  As the X-ray opaque material added to the synthetic resin, for example, fine particles made of a simple metal or a compound such as tungsten, barium sulfate, bismuth, gold, and platinum are preferable. The particle size of the X-ray opaque material is preferably 1 to 4 μm. And X-ray opaque substance content in a synthetic resin is 70 weight% or more, and it is preferable that it is 70 to 85 weight% especially. More preferably, it is 75 to 85% by weight.

  Further, as shown in FIG. 1, the synthetic resin film (first synthetic resin layer 3a, X-ray contrast material high-containing resin layer 3a) covering the tip 2b of the inner core 2 is substantially uniform at the tip 2b. It has an outer diameter. Thereby, the level | step difference etc. which were provided in the front-end | tip part 2b of the inner core 2 do not affect the outer surface shape of a guide wire. The term “substantially uniform” is not limited to a completely uniform one, and the tip 2b may be slightly narrow. Thus, by making the tip 2b substantially uniform, damage that the tip of the guide wire may cause to the blood vessel inner wall can be reduced. The outer diameter of the synthetic resin coating 3 is preferably about 200 to 500 μm, and particularly preferably 230 to 460 μm. Further, the synthetic resin coating 3 may cover the tip of the main body 2a. In this case, the thickness of the synthetic resin coating 3 on the main body 2a is preferably about 20 to 40 μm. It is.

  Moreover, as a synthetic resin used for the 2nd synthetic resin layer 3b, what was demonstrated in the 1st synthetic resin layer 3a can be used conveniently. For the synthetic resin (second synthetic resin) forming the second synthetic resin layer 3b, a material having good compatibility with the synthetic resin (first synthetic resin) constituting the first synthetic resin layer 3a is selected. It is preferable to do. Good compatibility indicates that the thermodynamic mutual solubility is good, in other words, does not separate between the two after curing.

  And as a 2nd synthetic resin which touches the inner core 2 directly and coat | covers the inner core 2 thinly, a thing with comparatively high rigidity is selected, and it coat | covers with the predetermined thickness with respect to the inner core 2. A relatively flexible resin may be selected as the first synthetic resin.

  As a combination of the synthetic resins having compatibility, for example, the first resin and the second resin may be the same resin or the same resin. For example, a flexible polyether polyamide block copolymer is selected as the first synthetic resin, nylon 12 having higher rigidity than the first synthetic resin is selected as the second synthetic resin, and both are made polyamide resins. Also, a polyolefin elastomer (for example, polyethylene elastomer) is selected as the flexible first synthetic resin, and polyethylene or a polyolefin elastomer (for example, polyethylene elastomer) that is harder than the first synthetic resin is selected as the second rigid synthetic resin. Both of them are made of polyolefin resin, polyester elastomer (for example, polyester elastomer) is used as the flexible first synthetic resin, and polyethylene terephthalate or first synthetic resin is used as the second rigid synthetic resin. Hard polyester base Select a streamer (for example, polyester elastomer), make them both polyester resins, select polyurethane elastomer as the flexible first synthetic resin, select polyurethane as the second rigid synthetic resin, and make both urethane types For example, a highly plasticized vinyl chloride resin is selected as the flexible first synthetic resin, a low plasticized vinyl chloride resin is selected as the second highly rigid synthetic resin, and both are made vinyl chloride resins. Can be considered.

  The second synthetic resin layer 3b may also contain a radiopaque material. The content of the radiopaque material in the second synthetic resin layer 3b needs to be lower than the content of the radiopaque material in the first synthetic resin layer 3a. As the X-ray impermeable substance, for example, fine particles made of simple metals or compounds such as tungsten, barium sulfate, bismuth, gold and platinum are preferable. The particle size of the X-ray opaque material is preferably 1 to 5 μm. And X-ray opaque substance content in 2nd synthetic resin is 45 weight% or less, and it is especially preferable that it is 30 weight% or less. More preferably, it is 20% by weight or less. And the 2nd synthetic resin layer 3b has coat | covered the front-end | tip part 2b of the inner core 2 with thickness about 1-10 micrometers. The second synthetic resin may encapsulate the entire inner core 2.

  7 and 8, the second synthetic resin layer 3b is not provided, and the X-ray contrast material-rich resin layer 3a directly covers the tip 2b of the inner core 2. It may be.

  In the medical wire of the present invention, the distal end portion 2b of the inner core 2 can have a small diameter, and the distal end portion 2b is relatively largely displaced under a constant stress and has an elastic strain characteristic that can be restored. Can be. Therefore, when the distal end portion 2b advances the bent portion of the blood vessel, a large bending deformation easily occurs with a relatively small load. Therefore, the responsiveness of the distal end portion 2b is good, and the blood vessel wall is not damaged. Repeatedly deformed and restored in response to changes in the bend, has good shape adaptability to meandering blood vessels, and is relatively easy to bend against blood vessel branches, so that it can be easily introduced into a predetermined blood vessel site. be able to. Further, by providing a metal up to the outer diameter of the wire without providing a synthetic resin coating on the inner core main body portion 2a of the wire, torque transmission is improved, and the tip portion 2b is attached to the predetermined blood vessel by the torque applied to the main body portion 2a. It can be surely and easily directed toward the site, and the operability of insertion into a complex blood vessel site is improved.

  Furthermore, the outer surface of the synthetic resin film 3 is coated with an anticoagulant such as heparin or urokinase, an antithrombotic material such as a block copolymer of urethane and silicone (registered trademark Abcosan), or a hydroxyethyl methacrylate-styrene copolymer. May be.

  The synthetic resin coating 3 (second synthetic resin layer 3b) is preferably in close contact with the inner core 2 and fixed to the tip 2b of the inner core 2. Alternatively, the synthetic resin coating 3 may be formed of a hollow tube and fixed to the inner core 2 by bonding or melt molding at the tip 2b of the inner core 2 or an appropriate portion of the inner core 2. The tip of the guide wire is preferably a hemispherical curved surface as shown in FIGS. 1 to 4 in order to prevent damage to the blood vessel wall and to improve the operability of the guide wire 1.

Further, it is preferable that a lubricating substance is fixed on the surface of the synthetic resin coating 3. A lubricious 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. This lubricating substance is in principle a chain-like and non-crosslinked polymer substance, and has a hydrophilic group such as —OH, —CONH ₂ , —COOH, —NH ₂ , —COO ⁻ , —SO ^{3 —} . Have. Furthermore, the lubricating substance is water-containing when wet (for example, when in contact with blood) and exhibits lubricity.

  By fixing such a lubricating substance to the synthetic resin coating 3 that is the outer surface of the guide wire, 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 in the catheter. Therefore, the guide wire can be easily operated.

  Specifically, as natural water-soluble polymer substances, starch-based compounds such as carboxymethyl starch and dialdehyde starch, cellulose-based compounds such as carboxymethylcellulose and hydroxyethylcellulose, tannin, lignin-based, alginic acid, gum arabic heparin, chitin, chitosan, etc. And other proteins such as polysaccharides, gelatin, and casein. Synthetic water-soluble polymer materials include polyvinyl alcohol, polyalkylene oxide series, polyethylene oxide, polyalkylene glycol series, polyethylene glycol, acrylic acid series, polyacrylic acid soda, maleic anhydride series, methyl vinyl ether maleic anhydride Acid copolymer, methyl vinyl ether maleic anhydride sodium salt, methyl vinyl ether maleic anhydride ammonium salt, maleic anhydride ethyl ester copolymer, phthalic acid-based polyhydroxyethyl phthalic acid ester, water-soluble polyester, polydimethylol propionic acid Esters and acrylamides such as polyacrylamide hydrolysates, polyacrylamide quaternized products, polyvinylpyrrolidone, polyethyleneimine, polyethylenes Honeto, such as water-soluble nylon is considered. Maleic anhydride is preferable, and maleic anhydride ethyl ester copolymer is particularly preferable.

  The derivative of the water-soluble polymer substance is not limited to water-solubility, and may be insolubilized as long as it has the above-mentioned water-soluble polymer substance as a basic component, and is hydrated when wet. Any material that exhibits lubricity can be used. For example, in the case of the above water-soluble polymer substance, esterified product obtained by addition, substitution, oxidation, reduction reaction, salt, amidated product, anhydride, halide, etherified product, hydrolyzed product, acetalized product, formalized product, Alkyrolated product, quaternized product, diazotized product, hydrazide product, sulfonated product, nitrated product, ion complex, diazonium group, azide group, isocyanate group, acid chloride group, acid anhydride group, imino carbonate group, amino group , Carboxyl groups, epoxy groups, hydroxyl groups, aldehyde groups, etc., cross-linked products with substances having two or more reactive functional groups, and vinyl compounds, acrylic acid, methacrylic acid, diene compounds, maleic anhydride, etc. Polymers and the like can be considered.

  In addition, as described later, the synthetic resin has a reactive functional group that is ionically or covalently bonded to the lubricating substance, or contains a compound having a reactive functional group, or a reactive functional group is introduced. . By combining the reactive functional group present or introduced in the synthetic resin with the above-mentioned lubricating substance, it becomes possible to impart lubricity on the surface of the synthetic resin, and it can be sustained without being dissolved in water. A lubricious surface can be obtained. Here, explanation will be made by the covalent bond.

  Although there is no restriction | limiting in particular as a lubricous substance, The cellulose type, maleic anhydride type, acrylamide type, polyethylene oxide type, water-soluble nylon, etc. which were mentioned above are used suitably. In particular, 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 suitable. The average molecular weight of these lubricating substances is not particularly limited, but those having a molecular weight of about 3 to 5 million have high lubricity, have an appropriate thickness, and are capable of obtaining a lubricating layer that does not significantly increase the degree of swelling when containing water. It is.

  In addition to polyvinyl pyrrolidone, the lubricating substances fixed on the surface of the synthetic resin by ionic bonds include the above-mentioned water-soluble polymer substances such as carboxylates, sulfonates, and ammonium salts. Specifically, Examples of the carboxylate include sodium salt of methyl vinyl ether maleic anhydride, polyacrylic acid soda, polyacrylamide hydrolyzate, carboxymethylcellulose sodium salt, sodium alginate, and the sulfonates include polystyrene sulfonate sodium and polyvinyl sulfonate sodium. Examples of ammonium salts include ammonium salts of methyl vinyl ether maleic anhydride and polyacrylamide quaternized products.

The reactive functional group present in the synthetic resin is not particularly limited as long as it reacts with the lubricating substance and is bonded or cross-linked and fixed, but 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 can be considered, and an isocyanate group, an amino group, an aldehyde group, and an epoxy group are particularly preferable.
Accordingly, polyurethane, polyamide, and the like are suitable as the synthetic resin having a reactive functional group.

  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, tetramethylenediamine and the like can be considered as low molecular weight polyamines. [I] Poly (alkylene polyamine) synthesized from [I] amine and alkylene dihalide or epichlorohydrin as a high molecular polyamine, [II] alkylene imine polymer obtained by ring-opening polymerization of alkylene imine such as ethylene imine, propylene imine, [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.

  Further, it is preferable to apply a silicon coat or the like to the main body portion 2a portion (portion not covered with the synthetic resin) in order to improve lubricity. As the silicone, those that form a thin film at room temperature or by heating are suitable. Moreover, you may coat | cover the thin part of the fluororesin which has low friction property in the main-body part 2a part (part which is not coat | covered with the synthetic resin).

Next, the manufacturing method of the medical wire of this invention is demonstrated.
The method for manufacturing a medical wire according to the present invention is a method for manufacturing a medical wire including an inner core 2 and a synthetic resin coating 3 that covers the tip 2b of the inner core 2.

  The method for producing a medical wire includes a step of preparing the inner core 2, a powder of a thermoplastic synthetic resin and a powder of an X-ray opaque material, and contains 70% by weight or more of an X-ray opaque material A step of producing a synthetic resin mixture, heating and melting the synthetic resin mixture to produce a pellet containing a high amount of X-ray opaque material, and at least the tip 2b of the inner core 2 is compatible with the thermoplastic synthetic resin. A step of forming a resin film 3b containing a thermoplastic resin, and heating and melting the high X-ray opaque substance-containing pellets on the resin film 3b to form a high X-ray opaque substance-containing resin film 3a. Process.

  As a process for preparing the inner core 2, for example, a stainless steel wire is used, as shown in FIGS. As shown in FIG. 5, what has the main-body part 2a and the front-end | tip part 2b diameter-reduced in steps can be produced, for example by etching the metal wire of the same outer diameter. The plate-like portion 4 at the tip can be formed by crushing or rolling and cutting.

  The inner core 2 includes a first straight portion 21a that is continuous with the plate-like portion 4, and a tapered portion 21b that is continuous with the straight portion 21a and has a diameter that decreases toward the tip. In particular, as shown in FIG. 4, a first straight portion 21 a that is formed on the distal end portion 2 b on the proximal end side from the plate-like portion 4 and that is continuous with the plate-like portion 4, and a first straight portion 21 a is continued. At the same time, the first taper portion 21b that decreases in diameter toward the tip, the second straight portion 22a that continues to the first taper portion 21b, and the second straight portion 22a that continues to the tip taper 21b and shrinks toward the tip. A second taper portion 22b having a diameter, a third straight portion 23a continuous with the second taper portion 22b, and a third taper continuous with the third straight portion 23a and having a diameter reduced toward the tip. A portion 23b is provided. In addition, the part (1st linear part) which continues with the plate-shaped part 4 does not become a linear part like the Example mentioned above, but may be a taper part.

As the inner core 2, stainless steel is preferably used. The outer diameter of the main body 2a of the inner core 2 is 0.2 to 0.51 mm, preferably 0.23 to 0.46 mm, and the length is 200 to 3000 mm, preferably 400 to 2600 mm. Moreover, the buckling strength (the yield stress at the time of load) of the main-body part 2a is 500-1200 g / mm < ² >, Preferably, it is 700-900 g / mm < ² >.

  Moreover, the length of the front-end | tip part 2b of the inner core 2 is 20-600 mm, Preferably, it is 30-500 mm. Further, the minimum outer diameter (excluding the plate-like portion) of the distal end portion 2b of the inner core 2 is 40 to 300 μm, and preferably 50 to 250 μm. The length of the plate-like portion 4 is 5 to 50 mm, preferably 10 to 30 mm, the thickness is 15 to 120 μm, preferably 20 to 90 μm, and the width is 45 to 45 mm. It is 380 micrometers, Preferably, it is 55-300 micrometers.

  The thermoplastic synthetic resin powder and the X-ray opaque material powder are mixed to produce a synthetic resin mixture containing 70% by weight or more of the X-ray opaque material, the synthetic resin mixture is heated and melted, and X The process of producing a pellet with a high content of radiopaque substances can be performed as follows.

  As a synthetic resin used for pellets containing a high amount of X-ray opaque material, a thermoplastic resin is used. For example, an olefin resin such as polyethylene, polypropylene, polybutene, ethylene-vinyl acetate copolymer, or a polyolefin elastomer thereof, Fluorine resin or soft fluorine resin, polyethylene terephthalate, polyester such as polybutylene terephthalate or polyester elastomer, methacrylic resin, polyphenylene oxide, modified polyphenylene ether, polyurethane or polyurethane elastomer, polyamide or polyamide elastomer, polycarbonate, polyacetal, polystyrene, Styrene resin such as styrene butadiene copolymer or styrene elastomer, thermoplastic Polyimides, such as polyvinyl chloride can be used. It is also possible to use polymer alloys or polymer blends based on these resins.

  As the X-ray opaque material added to the synthetic resin, for example, fine particles made of a simple metal or a compound such as tungsten, barium sulfate, bismuth, gold, and platinum are preferable. The particle size of the X-ray opaque material is preferably 1 to 5 μm. The amount of the radiopaque material added to the synthetic resin is such that the content of the radiopaque material in the produced high radiopaque material-containing pellet is 70% by weight or more. It adds so that it may become weight%. More preferably, it is 75 to 85% by weight.

  For example, the pellets are prepared by, for example, putting a radiopaque material together with a thermoplastic resin into a hensil mixer, mixing for 5 to 20 minutes, forming a strand with an extruder having a small burden on the resin, and then rapidly cooling the strand. Then, it can be performed by producing a strand cut pellet.

  In particular, it is preferable to use a powdery thermoplastic resin and knead by rotating the screw while heating and melting at a relatively low temperature in an extruder to produce pellets. Also, as the extruder, use a stone mill kneading extruder with a modified cross-section cylinder with a large cylinder surface area to efficiently disperse the heat of the resin in the cylinder and knead (shallow kneading) at a low rotational speed. Is preferred. As a result, the burden on the synthetic resin is reduced, so that deterioration of resin physical properties due to kneading is suppressed. By using a powdery thermoplastic resin, pellets can be formed at a relatively low temperature. Thereby, it is possible to improve the dispersibility of the contrast agent (filler) while causing a thermal effect on the resin.

The step of forming the resin film 3b containing a thermoplastic resin compatible with the thermoplastic synthetic resin on at least the tip 2b of the inner core can be performed as follows.
As a thermoplastic resin used here, what was demonstrated in formation of the pellet mentioned above can be used conveniently.
The synthetic resin (second synthetic resin) forming the synthetic resin film 3b is preferably selected from a material that is compatible with the synthetic resin (first synthetic resin) of the pellet containing a high amount of X-ray opaque material. . Good compatibility indicates that the thermodynamic mutual solubility is good, in other words, does not separate between the two after curing.
Then, as the second synthetic resin that is in direct contact with the inner core 2 and that covers the inner core 2 thinly, a relatively high rigidity resin is selected, and the first synthetic resin is coated with a predetermined thickness. A relatively flexible resin may be selected as the synthetic resin.

  As a combination of the synthetic resins having compatibility, for example, the first resin and the second resin may be the same resin or the same resin. For example, a flexible polyether polyamide block copolymer is selected as the first synthetic resin, nylon 12 having higher rigidity than the first synthetic resin is selected as the second synthetic resin, and both are made polyamide resins. Also, a polyolefin elastomer (for example, polyethylene elastomer) is selected as the flexible first synthetic resin, and polyethylene or a polyolefin elastomer (for example, polyethylene elastomer) that is harder than the first synthetic resin is selected as the second rigid synthetic resin. Both of them are made of polyolefin resin, polyester elastomer (for example, polyester elastomer) is used as the flexible first synthetic resin, and polyethylene terephthalate or first synthetic resin is used as the second rigid synthetic resin. Hard polyester base Select a streamer (for example, polyester elastomer), make them both polyester resins, select polyurethane elastomer as the flexible first synthetic resin, select polyurethane as the second rigid synthetic resin, and make both urethane types For example, a highly plasticized vinyl chloride resin is selected as the flexible first synthetic resin, a low plasticized vinyl chloride resin is selected as the second highly rigid synthetic resin, and both are made vinyl chloride resins. Can be considered.

  The second synthetic resin may also contain a radiopaque material. The content of the X-ray opaque material of the second synthetic resin needs to be lower than the content of the X-ray opaque material of the first synthetic resin. As the X-ray impermeable substance, for example, fine particles made of simple metals or compounds such as tungsten, barium sulfate, bismuth, gold and platinum are preferable. The particle size of the X-ray opaque material is preferably 1 to 5 μm. And X-ray opaque substance content in 2nd synthetic resin is 45 weight% or less, and it is especially preferable that it is 30 weight% or less. More preferably, it is 20% by weight or less. In this case, it may be performed in the same manner as the above-described method for producing the high X-ray opaque substance-containing pellet, and the low X-ray opaque substance-containing pellet may be produced. The synthetic resin film 3b made of the second synthetic resin is formed so as to cover the tip 2b of the inner core 2 with a thickness of about 1 to 10 μm. In addition, you may form the synthetic resin film 3b by a 2nd synthetic resin so that the whole inner core 2 may be enclosed. The synthetic resin film 3b can be formed by passing the inner core 2 through a die and extruding a molten synthetic resin from the die so as to adhere to the outer surface of the inner core 2. The thickness of the synthetic resin film 3b can be adjusted by the feed rate of the inner core 2 and the discharge amount of the molten synthetic resin. Alternatively, the synthetic resin coating 3b made of the second synthetic resin may be formed by immersing the tip 2b of the inner core 2 in a resin solution obtained by dissolving the synthetic resin in a solvent and pulling it up.

And on the front-end | tip part 2b of the inner core 2 in which the resin film 3b was formed as mentioned above, the X-ray opaque substance high content pellet is heat-melted and the X-ray opaque substance high content resin film 3a is formed. The process to perform is performed.
Formation of the resin film 3a containing X-ray opaque material can be performed by passing the inner core 2 through a die and extruding a molten synthetic resin from the die so as to adhere to the outer surface of the inner core 2. The X-ray opaque substance-rich resin coating 3a is preferably formed so that the outer diameter is substantially uniform. As a method for partially changing the thickness of the resin film 3a containing a high amount of X-ray opaque material, it is possible to adjust one or both of the feed speed of the inner core 2 and the discharge amount of the molten synthetic resin.

Next, the Example which applied the medical wire of this invention to the ultrasonic catheter is described.
FIG. 9 is an overall view of an ultrasonic catheter device in which the medical wire of the present invention is applied to an ultrasonic catheter. FIG. 10 is an enlarged cross-sectional view of the distal end portion of the ultrasonic catheter of FIG.
The ultrasonic catheter 5 includes an ultrasonic transducer 15 housed inside the distal end portion and a guide portion 6 that forms the distal end. The guiding portion 6 includes a main body portion 62a having high rigidity, an inner core 62 integrally formed with a distal end portion 62b having a smaller diameter and lower rigidity than the main body portion 62a, and a synthetic covering the front end portion 62b of the inner core 62. And a resin film 63. Further, the tip 62b of the inner core 62 is provided with a plate-like part 64 formed in a thin plate shape, and the synthetic resin film contains 70% by weight or more of an X-ray opaque material. It is formed of a synthetic resin.

  The ultrasonic catheter 5 of this embodiment includes a flexible tube 7, a guide portion 6 that is a medical wire of the present invention fixed to the distal end portion of the tube 7, and an outer tube 8 that covers the outer periphery of the tube 7. And X-ray contrast coils 9, 10, 11. Further, a passage (flow path) 12 that communicates the inside and the outside of the tube 7 is provided along the guide portion 6 inside the tube 7. A rotating shaft 13 is inserted into the tube 7. A housing 14 is fixed to the tip of the rotary shaft 13, and an ultrasonic transducer (transducer) 15 is installed in the housing 14. The proximal end of the ultrasonic catheter 5 is detachably connected to the external unit 18 via the hand operation unit 17. The external unit 18 includes a driving unit 19 that rotationally drives the rotary shaft 13 and a transmission / reception circuit that transmits ultrasonic waves to the ultrasonic transducer 15 and receives ultrasonic waves (reflected waves) received by the ultrasonic transducer 15. 20 are built in. The external unit 18 is connected to the console 30 and images and displays the ultrasonic waves received by the console 30.

  Examples of the tube 7 include polyolefins such as polyvinyl chloride, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polystyrene, polyurethane, polyamide, and polyimide. Polyoxymethylene, polyvinyl alcohol, polytetrafluoroethylene, polyvinylidene fluoride, other resins such as fluororesin, thermoplastic elastomers such as polyamide elastomer and polyester elastomer, various rubbers such as silicone rubber and latex rubber, etc. Tubes are used.

  Examples of the outer tube 8 include the same materials as those of the tube 7 described above. In this case, the constituent material of the outer tube 8 may be the same as or different from the constituent material of the tube 7. In particular, it is preferable to use a heat-shrinkable tube such as polyethylene that shrinks by heating as the outer tube 8 because of the ease of covering and mounting the tube 7. Further, the outer tube 8 and the tube 7 may be bonded by fusion (thermal fusion, high frequency fusion, ultrasonic fusion, etc.) or an adhesive. Furthermore, the distal end portion 31 of the outer tube 8 protrudes toward the distal end side from the distal end of the tube 7 and encloses the outer periphery of the proximal end portion of the guide portion 6. Thereby, the detachment of the outer tube 8 from the tube 7 is prevented. Here, as shown in FIG. 9, the distal end portion 31 of the outer tube 8 is reduced in diameter by, for example, thermal contraction. The distal end portion 31 of the outer tube 8 is preferably in close contact with the outer peripheral surface of the guide portion 6 except for the passage 12.

  And the guidance | induction part 6 is being fixed to the front-end | tip part of the tube 7 so that about 5-25 mm may protrude from the front-end | tip of the tube 7 by predetermined length. In particular, it preferably projects about 10 to 20 mm. The guiding portion 6 is fixed to the inner surface of the tube by an adhesive layer 16. In addition, in order to increase the bonding force (adhesive strength) of the adhesive layer 16 to the guiding portion 6, the surface of the guiding portion 6 is formed with a synthetic resin film having adhesiveness with the adhesive, It is preferable that the process which forms a groove | channel, the roughening process, and the process which makes it porous are performed. Thereby, even when a strong pulling force, pressing force, torsional torque, or the like acts on the tip wire, peeling (detachment) and damage of the adhesive layer 16 are prevented.

  Although it does not specifically limit as an adhesive agent which comprises the adhesive bond layer 16, It is preferable that it is a photocurable or thermosetting adhesive. In particular, a photocurable adhesive such as an ultraviolet curable adhesive is preferable in that it is easy to adjust the degree of progress of curing. Moreover, it does not specifically limit as a composition of the adhesive agent which comprises the adhesive bond layer 16, An acrylic adhesive, an epoxy-type adhesive agent, etc. are mentioned. The adhesive is cured (solidified) to form the adhesive layer 16. The method of curing the adhesive is performed according to the type and characteristics of the adhesive. For example, when the adhesive is an ultraviolet curable adhesive, it is cured by irradiating ultraviolet rays from the outer surface of the tube 7, and when the adhesive is a thermosetting adhesive, it is heated and cured from the outer surface of the tube 7. Let In addition, when hardening an ultraviolet curable adhesive, the degree of hardening can be adjusted by adjusting the irradiation amount of an ultraviolet-ray suitably.

  The guide unit 6 functions as a so-called guide wire that guides the distal end of the catheter 5 to a target blood vessel site. The guiding portion 6 includes a main body portion 62a having high rigidity, an inner core 62 integrally formed with a distal end portion 62b having a smaller diameter and lower rigidity than the main body portion 62a, and a synthetic covering the front end portion 62b of the inner core 62. And a resin coating 63.

  The inner core 62 has a main body portion 62a and a distal end portion 62b and is integrally formed. As shown in FIG. 10, the distal end portion 62b is formed to have a diameter that gradually decreases from the distal end of the main body portion 62a toward the distal end, and the rigidity of the distal end portion 62b is lower than that of the main body portion 62a. Yes. Thus, by gradually reducing the diameter of the tip 62b of the inner core 62, the tip 62b is gradually bent when a force is applied to the tip, so that the operability is improved.

  The distal end portion 62b of the inner core 62 used in the ultrasonic catheter 5 of this embodiment has a plate-like portion 64, a first straight portion continuous with the plate-like portion 64, and the straight portion. And a tapered portion that decreases in diameter toward the tip. In particular, in the embodiment shown in FIG. 10, the distal end portion 62 b of the inner core 62 is formed on the proximal end side with respect to the plate-like portion 64 and is continuous with the plate-like portion 64, and the first straight-line portion. And a first taper portion that is reduced in diameter toward the tip, a second straight portion that is continuous with the first taper portion, and a second straight portion that is continuous with the first taper portion and reduced in diameter toward the tip. A second tapered portion, a third linear portion that is continuous with the second tapered portion, and a third tapered portion that is continuous with the third linear portion and is reduced in diameter toward the tip. . In addition, the part (1st linear part) continuous with the plate-shaped part 64 does not become a linear part like the Example mentioned above, but may be a taper part.

  And the plate-shaped part 64 currently formed in the front-end | tip of the inner core 62 is formed by crushing (rolling) a 1st linear part, As a result, like what is shown in FIG. The plate-like portion 64 is thinner than the outer diameter of the straight portion, and the width is wider than the outer diameter of the straight portion as shown in FIG. Thus, by making the tip of the inner core 62 flat, the tip of the inner core 62 becomes more flexible. And by providing this flat plate part, the outer area of the front-end | tip of the inner core 62 becomes large, a contact area with a resin film increases, and the adhesion maintenance of the resin film becomes certain. Although the surface area is reduced, the tip may be plate-shaped as described above, and etching may be performed to make the width equal to the outer diameter of the straight portion (portion continuous with the plate-shaped portion). . By doing in this way, the front-end | tip of the inner core 62 can be made more flexible.

As the inner core 62, stainless steel is preferably used. The outer diameter of the main body 62a of the inner core 62 is 0.05 to 0.2 mm, preferably 0.1 to 0.15 mm, and the length is 5 to 20 mm, preferably 7 to 15 mm.
Moreover, the length of the front-end | tip part 62b of the inner core 62 is 5-25 mm, Preferably, it is 10-20 mm. Further, the minimum outer diameter (excluding the plate-like portion 64) of the tip end portion 62b of the inner core 62 is 40 to 300 μm, and preferably 50 to 250 μm. The length of the plate-like portion 64 is 5 to 50 mm, preferably 10 to 30 mm, the thickness is 15 to 120 μm, preferably 20 to 90 μm, and the width is 45 to 45 mm. It is 380 micrometers, Preferably, it is 55-300 micrometers.
Further, the plate-like portion 64 is not limited to a flat plate-like shape as described above, and has an elliptical cross section, conversely, the upper or lower surface of the plate-like portion 64 or both are concave. It may be the one that became.

Further, as shown in FIG. 7, the plate-like portion 64 may be thinner toward the tip. In this way, the tip can be made more flexible. In this case, when the plate-like portion 64 is formed by crushing (rolling) a portion having the same outer diameter, the width becomes wider toward the tip, as shown in FIG. In this case as well, etching may be performed so that the width is the same as the outer diameter of the straight portion (portion continuous with the plate-like portion). By doing in this way, the front-end | tip of the inner core 62 can be made more flexible.
The dimensions of the main body 62a, the tip 62b, and the plate-like part 64 of the inner core 62 are not necessarily the dimensions described above, and may be a part.

  The inner core 62 is covered with a synthetic resin. In this embodiment, the synthetic resin film 63 is an upper layer, and a first synthetic resin layer 63a formed of a synthetic resin containing 70% by weight or more of an X-ray opaque material, and the first synthetic resin. A layer 63a and a second synthetic resin layer 63b located between the tips of the inner core 62 are provided.

  As the synthetic resin used for the first synthetic resin layer 63a, the synthetic resin used for the first synthetic resin layer 3a described above can be suitably used. Further, as the X-ray opaque material added to the synthetic resin, for example, fine particles made of a simple metal or a compound such as tungsten, barium sulfate, bismuth, gold, and platinum are preferable. The particle size of the X-ray opaque material is preferably 1 to 4 μm. And X-ray opaque substance content in a synthetic resin is 70 weight% or more, and it is preferable that it is 70 to 85 weight% especially. More preferably, it is 75 to 85% by weight.

  Further, as shown in FIG. 10, the synthetic resin film (first synthetic resin layer 63a) covering the inner core 62 has a substantially uniform outer diameter at the tip 62b. Thereby, the level | step difference etc. which were provided in the front-end | tip part 62b of the inner core 62 do not affect the outer surface shape of an ultrasonic catheter. The term “substantially uniform” is not limited to being completely uniform, and the tip may be slightly narrower. Thus, by making the tip portion 62b substantially uniform, damage that the tip of the ultrasonic catheter may cause to the blood vessel inner wall can be reduced. The outer diameter of the synthetic resin coating is preferably about 200 to 500 μm, particularly preferably 230 to 460 μm. Further, the thickness of the synthetic resin film on the main body 62a is preferably about 100 to 150 μm.

  Further, as the synthetic resin used for the second synthetic resin layer 63b, those described for the synthetic resin (second synthetic resin) forming the second synthetic resin layer 3b described above can be suitably used. For the synthetic resin (second synthetic resin) that forms the second synthetic resin layer 63b, a material that is compatible with the synthetic resin (first synthetic resin) that constitutes the first synthetic resin layer 63a is selected. It is preferable to do. Good compatibility indicates that the thermodynamic mutual solubility is good, in other words, does not separate between the two after curing. This is also the same as described above.

  Further, the second synthetic resin layer 63b may also contain a radiopaque material. The content of the radiopaque material in the second synthetic resin layer 63b needs to be lower than the content of the radiopaque material in the first synthetic resin layer. As the X-ray impermeable substance, for example, fine particles made of simple metals or compounds such as tungsten, barium sulfate, bismuth, gold and platinum are preferable. The particle size of the X-ray opaque material is preferably 1 to 5 μm. The content of the radiopaque substance in the second synthetic resin is 40% by weight or less, and particularly preferably 30% by weight or less. More preferably, it is 20% by weight or less. The second synthetic resin layer 63b covers the tip 62b of the inner core 62 with a thickness of about 1 to 10 μm. The second synthetic resin may encapsulate the entire inner core 62.

  Furthermore, the outer surface of the synthetic resin film is coated with an anti-coagulant such as heparin or urokinase, an anti-thrombotic material such as a block copolymer of urethane and silicone (registered trademark Abcosan), or a hydroxyethyl methacrylate-styrene copolymer. Also good.

The synthetic resin film (second synthetic resin layer 63 b) is preferably in close contact with the inner core 62 and fixed at the tip 62 b of the inner core 62. Alternatively, the synthetic resin coating 2 may be formed of a hollow tube and fixed to the inner core 62 by bonding or melt molding at the tip 62b of the inner core 62 or an appropriate portion of the inner core 62. The tip of the ultrasonic catheter is preferably a curved surface such as a hemisphere as shown in FIG. 10 in order to prevent damage to the blood vessel wall and improve the operability of the ultrasonic catheter.
Furthermore, it is preferable that the lubricating substance is fixed to the surface of the portion exposed to the outside of the synthetic resin coating. As the lubricating substance, those described above can be used.

  The X-ray contrast coil 9 is composed of a linear body wound around the outer periphery of the reduced diameter portion 31 of the tube 7. Thereby, the position of the ultrasonic catheter 5 in the living body under X-ray fluoroscopy, particularly the position of the distal end portion of the ultrasonic catheter 5 can be confirmed. Examples of the material of the X-ray contrast coil 9 include gold, silver, platinum, tungsten, palladium or alloys thereof, barium carbonate, and barium sulfate having X-ray contrast properties. In this case, the winding of the linear body is not limited to a single winding as shown in FIG.

  Further, X-ray contrast coils 10 and 11 are provided on the proximal end side from the guiding portion 6. In this embodiment, the X-ray contrast coil 10 is constituted by a coil (elastic body) wound spirally along the inner peripheral surface of the tube 7. Similarly, the X-ray contrast coil 11 is formed of a coil wound spirally. Examples of the material constituting these coils include the same material as that of the X-ray contrast coil 9 described above. Note that the tip of the X-ray contrast coil 10 is embedded and fixed in the adhesive layer 16. The X-ray contrast coil 11 is fixed to the distal end of the housing 14 and is provided so as to be inserted inside the coil 10.

In the adhesive layer 16, a passage (flow path) 12 that communicates the inside and the outside of the tube 7 is provided along the guide portion 6. For example, the passage 12 is used as a flow path (priming port) for supplying the ultrasonic transmission liquid when the tube 7 is filled with the ultrasonic transmission liquid (priming liquid). In addition, when inject | pouring an ultrasonic transmission liquid from the base end side of the ultrasonic catheter 5, this channel | path 12 functions as an exhaust port which discharges the air in the tube 7. FIG. In addition, the manufacturing method of the said channel | path 12 inserts a channel | path formation member (not shown) in the tube 7 along the guidance | induction part 6 with the insertion of this guidance | induction part 6 first. As this channel | path formation member, the linear body comprised with various metal materials, hard resin, etc. is used. Then, an adhesive (not shown) is injected from the opening of the tube 7. After the adhesive (not shown) is solidified, the passage forming member is extracted and the passage is produced. Moreover, it is preferable to apply a release agent such as silicone to the surface of the passage forming member so that the passage forming member is easily peeled from the adhesive layer 16 when the passage forming member is removed. In FIG. 10, the passage 12 is formed in the adhesive layer 16, but is not limited thereto, and may be formed, for example, in the guide portion 6 or in the side walls of the tube 7 and the outer tube 8. .
Furthermore, the antithrombotic material as described above may be coated on the outer surface of the ultrasonic catheter 5 or may be coated with the above-described lubricating substance.

Next, the Example which applied the medical wire of this invention to the catheter with an expansion body is described.
FIG. 11 is an external view of an embodiment in which the medical wire of the present invention is applied to a catheter with an expansion body. FIG. 12 is an enlarged cross-sectional view of the distal end portion of the catheter with the expansion body of FIG.
The expander-equipped catheter 40 includes an expandable expansion body 48 provided at the distal end portion, a fluid flow lumen 46 for expanding the expansion body 48, and a guide portion 6 that forms the distal end. The guiding portion 6 includes a main body portion 62a having high rigidity, an inner core 62 integrally formed with a distal end portion 62b having a smaller diameter and lower rigidity than the main body portion 62a, and a synthetic covering the front end portion 62b of the inner core 62. And a resin film 63. Further, the tip 62b of the inner core 62 includes a plate-like part 64 formed in a thin plate shape, and the synthetic resin film 63 contains 70% by weight or more of an X-ray opaque material. Formed of synthetic resin.

  The catheter 40 with the expansion body of this embodiment is attached to the distal end of the catheter main body 44 and the catheter main body 44 formed by the flexible tubular body 42 having the lumen 46 formed therein and having the opening 50 at the distal end. The guiding wire 6 for guiding the catheter with the expansion body, which is the medical wire of the present invention, has a distal end portion and a proximal end portion, and the proximal end portion is attached to the catheter body 44, and The guide portion 6 is attached, and further includes an expansion body 48 communicating with the lumen 46 through the opening 50 and a hub 45 attached to the proximal end of the catheter body portion 44.

  The catheter body 44 includes a flexible tubular body 42 and a synthetic resin layer 43 that covers the surface of the flexible tubular body 42. In addition, the synthetic resin layer 43 is not necessarily provided, but is provided in order to suppress adhesion of blood to the surface of the flexible tubular body 42 and to make it easy to fix the expansion body described later. Is preferred.

Examples of the flexible tubular body 42 include a TiNi alloy of 49 to 58 atomic% Ni, a Cu—Zn alloy of 38.5 to 41.5 wt% Zn, and a Cu—Zn—X alloy of 1 to 10 wt% X (X = Be, Si, Sn, Al, Ga), a super elastic metal tube such as a Ni-Al alloy of 36 to 38 atomic% Al, and a stainless steel tube are preferably used. The TiNi alloy is particularly preferable. The flexible tubular body 42 has an outer diameter of 0.6 to 2.0 mm, preferably 0.8 to 1.6 mm, a wall thickness of 50 to 200 μm, preferably 80 to 150 μm, and the length is 500 to 4000 mm, more preferably 1000 to 3000 mm, buckling strength (yield stress under load) is 5 to 200 kg / mm ² (22 ° C.), more preferably 8 to 150 kg / mm ² , restoring stress (unloading) The yield stress at the time is 3 to 180 kg / mm ² (22 ° C.), more preferably 5 to 130 kg / mm ² . The outer tube 63 has an outer diameter of 0.60 to 2.00 mm, preferably 0.80 to 1.60 mm, and an inner diameter of 0.50 to 1.90 mm, preferably 0.60 to 1.40 mm. . The wall thickness is 0.05 to 0.75 mm, preferably 0.1 to 0.3 mm. A plurality of openings 50 are provided on the side surface of the distal end portion of the flexible tubular body 42. The synthetic resin layer 43 covers the entire flexible tubular body 42.

  Examples of the synthetic resin layer 43 include thermoplastic resins such as polyolefin (for example, polyethylene, polypropylene, ethylene-propylene copolymer, etc.), polyvinyl chloride, ethylene-vinyl acetate copolymer, polyamide elastomer, polyurethane, and fluorine resin. Silicone rubber or the like can be used, and polyolefin, polyamide elastomer or polyurethane is preferable. The synthetic resin layer 43 is preferably flexible to the extent that it does not hinder the bending of the flexible tubular body 42. The thickness of the synthetic resin layer 43 is 0.005 to 0.3 mm, preferably 0.01 to 0.2 mm. Furthermore, the anti-thrombotic material as described above may be coated on the outer surface of the synthetic resin layer 43, or the lubricating material described above may be coated.

The guiding portion 6 is fixed to the distal end of the catheter main body 44. This is for guiding the distal end of the catheter 40 with the expansion body to a target blood vessel site.
The guiding unit 6 functions as a so-called guide wire that guides the distal end of the catheter 40 to a target blood vessel site. The guiding portion 6 includes a main body portion 62a having high rigidity, an inner core 62 integrally formed with a distal end portion 62b having a smaller diameter and lower rigidity than the main body portion 62a, and a synthetic covering the front end portion 62b of the inner core 62. And a resin coating 3.
The inner core 62 has a main body portion 62a and a distal end portion 62b and is integrally formed. As shown in FIG. 12, the distal end portion 62b is formed so that its diameter gradually decreases from the distal end of the main body portion 62a toward the distal end, and the rigidity of the distal end portion 62b is lower than that of the main body portion 62a. Yes. Thus, by gradually reducing the diameter of the tip 62b of the inner core 62, the tip 62b is gradually bent when a force is applied to the tip, so that the operability is improved.

  The distal end portion 62b of the inner core 62 used in the catheter 40 with the expansion body according to this embodiment is continuous with the plate-like portion 64, the first straight portion continuous with the plate-like portion 64, and the straight portion. In addition, a taper portion that decreases in diameter toward the tip is provided. In particular, in the embodiment shown in FIG. 10, the distal end portion 62 b of the inner core 62 is formed on the proximal end side with respect to the plate-like portion 64 and is continuous with the plate-like portion 64, and the first straight-line portion. And a first taper portion that is reduced in diameter toward the tip, a second straight portion that is continuous with the first taper portion, and a second straight portion that is continuous with the first taper portion and reduced in diameter toward the tip. A second tapered portion, a third linear portion that is continuous with the second tapered portion, and a third tapered portion that is continuous with the third linear portion and is reduced in diameter toward the tip. . In addition, the part (1st linear part) continuous with the plate-shaped part 64 does not become a linear part like the Example mentioned above, but may be a taper part.

  And the plate-shaped part 64 currently formed in the front-end | tip of the inner core 62 is formed by crushing (rolling) a 1st linear part, As a result, like what is shown in FIG. The plate-like portion 64 is thinner than the outer diameter of the straight portion, and the width is wider than the outer diameter of the straight portion as shown in FIG. Thus, by making the tip of the inner core 62 flat, the tip of the inner core 62 becomes more flexible. And by providing this flat plate part, the outer area of the front-end | tip of the inner core 62 becomes large, a contact area with a resin film increases, and the adhesion maintenance of the resin film becomes certain. Although the surface area is reduced, the tip may be plate-shaped as described above, and etching may be performed to make the width equal to the outer diameter of the straight portion (portion continuous with the plate-shaped portion). . By doing in this way, the front-end | tip of the inner core 62 can be made more flexible.

As the inner core 62, stainless steel is preferably used. The outer diameter of the main body 62a of the inner core 62 is 0.05 to 0.2 mm, preferably 0.1 to 0.15 mm, and the length is 5 to 20 mm, preferably 7 to 15 mm.
Moreover, the length of the front-end | tip part 62b of the inner core 62 is 5-25 mm, Preferably, it is 10-20 mm. Further, the minimum outer diameter (excluding the plate-like portion 64) of the tip end portion 62b of the inner core 62 is 40 to 300 μm, and preferably 50 to 250 μm. The length of the plate-like portion 64 is 5 to 50 mm, preferably 10 to 30 mm, the thickness is 15 to 120 μm, preferably 20 to 90 μm, and the width is 45 to 45 mm. It is 380 micrometers, Preferably, it is 55-300 micrometers.

Further, the plate-like portion 64 is not limited to a flat plate-like shape as described above, and has an elliptical cross section, conversely, the upper or lower surface of the plate-like portion 64 or both are concave. It may be the one that became.
Further, as shown in FIG. 7, the plate-like portion 64 may be thinner toward the tip. In this way, the tip can be made more flexible. In this case, when the plate-like portion 64 is formed by crushing (rolling) a portion having the same outer diameter, the width becomes wider toward the tip, as shown in FIG. In this case as well, etching may be performed so that the width is the same as the outer diameter of the straight portion (portion continuous with the plate-like portion). By doing in this way, the front-end | tip of the inner core 62 can be made more flexible.
The dimensions of the main body 62a, the tip 62b, and the plate-like part 64 of the inner core 62 are not necessarily the dimensions described above, and may be a part.

  And the front-end | tip part 62b of the inner core 62 is coat | covered with the synthetic resin. In this embodiment, the synthetic resin film 63 is an upper layer, and a first synthetic resin layer 63a formed of a synthetic resin containing 70% by weight or more of an X-ray opaque material, and the first synthetic resin. A layer 63a and a second synthetic resin layer 63b located between the tips of the inner core 62 are provided.

  As the synthetic resin used for the first synthetic resin layer 63a, the synthetic resin used for the first synthetic resin layer 3a described above can be suitably used. Further, as the X-ray opaque material added to the synthetic resin, for example, fine particles made of a simple metal or a compound such as tungsten, barium sulfate, bismuth, gold, and platinum are preferable. The particle size of the X-ray opaque material is preferably 1 to 4 μm. And X-ray opaque substance content in a synthetic resin is 70 weight% or more, and it is preferable that it is 70 to 85 weight% especially. More preferably, it is 75 to 85% by weight.

  Further, as shown in FIG. 12, the synthetic resin film (first synthetic resin layer 63a) covering the front end 62b of the inner core 62 has a substantially uniform outer diameter at the front end 62b. Thereby, the level | step difference etc. which were provided in the front-end | tip part 62b of the inner core 62 do not affect the outer surface shape of the catheter with an expansion body. The term “substantially uniform” is not limited to being completely uniform, and the tip may be slightly narrower. Thus, by making the tip portion substantially uniform, it is possible to reduce the damage that the tip of the catheter with the expansion body may cause to the blood vessel inner wall. The outer diameter of the synthetic resin coating is preferably about 200 to 500 μm, particularly preferably 230 to 460 μm. The synthetic resin coating may cover the tip of the main body 62a. In this case, the thickness of the synthetic resin coating on the main body 62a is preferably about 100 to 150 μm. .

  Further, as the synthetic resin used for the second synthetic resin layer 63b, those described for the synthetic resin (second synthetic resin) forming the second synthetic resin layer 3b described above can be suitably used. For the synthetic resin (second synthetic resin) that forms the second synthetic resin layer 63b, a material that is compatible with the synthetic resin (first synthetic resin) that constitutes the first synthetic resin layer 63a is selected. It is preferable to do. Good compatibility indicates that the thermodynamic mutual solubility is good, in other words, does not separate between the two after curing. This is also the same as described above.

  Further, the second synthetic resin layer 63b may also contain a radiopaque material. The content of the radiopaque material in the second synthetic resin layer 63b needs to be lower than the content of the radiopaque material in the first synthetic resin layer 63a. As the X-ray impermeable substance, for example, fine particles made of simple metals or compounds such as tungsten, barium sulfate, bismuth, gold and platinum are preferable. The particle size of the X-ray opaque material is preferably 1 to 5 μm. The content of the radiopaque substance in the second synthetic resin is 40% by weight or less, and particularly preferably 30% by weight or less. More preferably, it is 20% by weight or less. The second synthetic resin layer 63b covers the tip 62b of the inner core 62 with a thickness of about 1 to 10 μm. The second synthetic resin may encapsulate the entire inner core 62.

  Furthermore, the outer surface of the synthetic resin film is coated with an anticoagulant such as heparin or urokinase, an antithrombotic material such as a block copolymer of urethane and silicone (registered trademark Abcosan), or a hydroxyethyl methacrylate-styrene copolymer. Also good.

The synthetic resin film (second synthetic resin layer 63 b) is preferably in close contact with the inner core 62 and fixed at the tip 62 b of the inner core 62. Alternatively, the synthetic resin coating 2 may be formed of a hollow tube and fixed to the inner core 62 by bonding or melt molding at the tip 62b of the inner core 62 or an appropriate portion of the inner core 62. The distal end of the catheter with the expansion body is preferably a curved surface such as a hemisphere as shown in FIG. 12 in order to prevent damage to the blood vessel wall and to improve the operability of the catheter with the expansion body.
Furthermore, it is preferable that the lubricating substance is fixed to the surface of the portion exposed to the outside of the synthetic resin coating. As the lubricating substance, those described above can be used.

  Further, as shown in FIG. 12, the inner core 62 has a flange portion at its proximal end portion, and is inserted into the distal end of the catheter main body portion 44 and fixed by soldering. As the solder, a hard solder such as a silver solder or a gold solder can be suitably used. Further, the guide portion 6 may be fixed by inserting the tip of the catheter body 44 and then caulking the tip of the catheter body 44.

  Next, the expansion body 48 can be contracted or folded, and can be folded on the outer periphery of the catheter main body 44 and the guide portion when not expanded. And the expansion body 48 is a foldable thing which has the substantially cylindrical part of the substantially same diameter by which at least one part is substantially cylindrical shape so that the constriction part of the blood vessel can be expanded easily. The substantially cylindrical portion may not be a complete cylinder, but may be a polygonal column. The base end portion of the expansion body 48 is liquid-tightly fixed to the front end portion of the main body portion by an adhesive or heat fusion, and the front end portion is similarly liquid-tightly fixed to the front end portion of the guide portion 6. ing. The expansion body 48 forms an expansion space between the inner surface of the expansion body 48 and the outer surface of the catheter main body 44. This expansion space communicates with the lumen 46 through an opening 50 provided in the catheter main body 44.

  As the forming material of the expansion body 48, a material having a certain degree of flexibility is preferable. For example, polyolefin such as polyethylene, polypropylene, ethylene-propylene copolymer, polyvinyl chloride, ethylene-vinyl acetate copolymer, cross-linked type Thermoplastic resins such as ethylene-vinyl acetate copolymer, polyamide elastomer and polyurethane, silicone rubber, latex rubber and the like can be used, preferably the above-mentioned thermoplastic resin, more preferably cross-linked ethylene-vinyl acetate copolymer. It is a coalescence.

Furthermore, the expansion body 48 has a tapered shape at the front and rear of the cylindrical portion up to the above-described fixing portion between the catheter main body 44 and the guide portion 6.
As the size of the expanded body 48, the outer diameter of the cylindrical portion when expanded is 1.50 to 35.00 mm, preferably 2.00 to 30.00 mm, and the length is 10.00 to 80.00 mm. It is 00 mm, preferably 15.00-75.00 mm, and the total length of the expansion body 48 is 15.00-120.00 mm, preferably 20.00-100.00 mm.
Then, the outer surface of the expansion body may be coated with the antithrombotic material as described above, or may be coated with the above-described lubricating substance.

  Further, the catheter with an expansion body is not limited to the above-mentioned type, for example, a catheter main body formed by a flexible tubular body having a lumen formed therein and having an opening at the tip. A guide portion for guiding the catheter attached to the distal end of the main body portion, a distal end portion and a proximal end portion, and the proximal end portion is attached to a position proximal to the opening of the catheter main body portion; May be a catheter with an expansion body that is attached to the distal end portion of the catheter body and has a contractible or foldable expansion body that communicates with the lumen through the opening. The only difference between the catheter with the expansion body and the catheter 40 with the expansion body of the embodiment shown in FIGS. 11 and 12 is the position where the distal end portion of the expansion body is fixed. About points other than the above, it is the same as what was mentioned above.

Next, specific examples of the guide wire of the present invention will be described.
(Preparation of high X-ray contrast material pellets)
Add 5kg of thermoplastic polyurethane powder (PENDEX-T-5000P, manufactured by Dainippon Ink Co., Ltd.) and 20kg of tungsten powder (particle size: 3μm, manufactured by Nippon Shin Metal Co., Ltd.) to a hensil mixer and mix for 10 minutes at room temperature. Then, a strand is formed by heating and melting at 160 to 205 ° C. with an extruder with a modified cross-section cylinder (KCK Co., Ltd. continuous kneading extruder), and then rapidly cooling to form a strand cut pellet containing a high amount of X-ray contrast material. 25 kg (particle size 2 mm, X-ray contrast material content 80% by weight) was prepared.

(Production of inner core)
It was prepared by etching a 400 mm tip of stainless steel having a total length of 1800 mm and a wire diameter of 0.34 mm, and repeatedly providing a tapered portion and a straight portion three times to reduce the diameter. From the distal end side, the length of the first straight portion is 20 mm, the wire diameter is 65 μm, the length of the first taper portion is 50 mm, the length of the second straight portion is 50 mm, the wire diameter is 200 μm, The length of the second tapered portion was 90 mm, the length of the third linear portion was 120 mm, the wire diameter was 300 μm, and the length of the third tapered portion was 70 mm. And the most advanced part (to 15 mm from the front-end | tip) of a 1st linear part was rolled, and it processed into the flat form of thickness 30micrometer and width 0.1mm.

(Formation of a resin layer containing a low X-ray contrast material)
Polyurethane pellets (PANDEX-T-5210, manufactured by Dainippon Ink Co., Ltd.) are dissolved in a solvent, and tungsten powder (particle size: 3 μm, manufactured by Nippon Shin Metal Co., Ltd.) is dissolved in the polyurethane at 5% by weight with respect to the polyurethane weight. Thus, an added tungsten powder-containing resin solution was prepared. Then, about 400 mm of the tip of the inner core was dipped in this tungsten powder-containing resin solution, pulled up and dried to form a low X-ray contrast material-containing resin layer on the tip of the inner core.

(Formation of X-ray contrast material-rich resin layer)
A high X-ray contrast material-containing strand cut pellet is put into an extruder, and a melted X-ray contrast material-rich resin is formed on the X-ray contrast material-low-resin layer forming portion at the tip of the inner core (400 mm from the tip). And then passed through a heating die to form a resin layer containing a high X-ray contrast material. The outer diameter of the tip of the wire after forming the resin layer containing a high X-ray contrast material was 0.34 mm, which was almost uniform.

  Then, a solution of maleic anhydride ethyl ester copolymer dissolved in tetrahydrofuran so as to be 5.0% by weight was applied on the X-ray contrast material-rich resin layer, and the maleic anhydride ethyl ester copolymer was coated with Fixed and formed a lubricious surface. Moreover, the guide wire for catheters was produced by silicon-coating the resin layer non-formation part (main part) of an inner core.

  The guide wire has an overall length of about 1800 mm, an overall diameter of 0.34 mm, an abutment resistance of the guide wire 30 mm of about 0.4 g, and a bending load of the main body of about 77 g. there were. When X-ray imaging of the entire guide wire was performed, a high X-ray contrast image was obtained at the tip.

FIG. 1 is a sectional view of an embodiment in which the medical wire of the present invention is applied to a guide wire. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is an enlarged cross-sectional view of the distal end portion of the guide wire shown in FIG. FIG. 4 is an enlarged cross-sectional view of the distal end portion of the guide wire shown in FIG. FIG. 5 is an external view of the inner core. FIG. 6 is an enlarged perspective view of the distal end portion of the inner core. FIG. 7 is an enlarged cross-sectional view of the distal end portion of another embodiment in which the medical wire of the present invention is applied to a guide wire. 8 is a cross-sectional view taken along line BB in FIG. FIG. 9 is an overall view of an ultrasonic catheter device in which the medical wire of the present invention is applied to an ultrasonic catheter. FIG. 10 is an enlarged cross-sectional view of the distal end portion of the ultrasonic catheter of FIG. FIG. 11 is an external view of an embodiment in which the medical wire of the present invention is applied to a catheter with an expansion body. FIG. 12 is an enlarged cross-sectional view of the distal end portion of the catheter with the expansion body of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Medical wire 2 Inner core 2a Main-body part 2b Tip part 3 Synthetic resin film 3a 1st synthetic resin layer (X-ray contrast material high content resin layer)
3b Second synthetic resin layer 4 Plate-shaped part

Claims (9)

A medical wire comprising a highly rigid main body, an inner core integrally formed with a tip having a smaller diameter and lower rigidity than the main body, and a synthetic resin film covering the tip of the inner core. The tip portion of the inner core includes a plate-like portion formed in a thin plate shape, and the synthetic resin film is an upper layer and is made of a synthetic resin containing 70% by weight or more of an X-ray opaque material. A synthetic resin comprising the formed first synthetic resin layer and the second synthetic resin layer positioned between the first synthetic resin layer and the tip of the inner core, and forming the second synthetic resin layer , the first is higher than the synthetic resin rigid resin, and those containing an X-ray opaque substance at a lower content than the content of the X-ray opaque material in the first synthetic resin layer Furthermore, the resin forming the first synthetic resin layer and the second synthetic resin layer are shaped. To the resin, medical, characterized in that both are both either polyamide resin, both together a polyolefin resin, both together urethane resin, both together polyester resin, both together a vinyl chloride resin For wire. The medical wire according to claim 1 , wherein the content of the radiopaque material in the second synthetic resin is 45% by weight or less. A medical wire comprising a highly rigid main body, an inner core integrally formed with a tip having a smaller diameter and lower rigidity than the main body, and a synthetic resin film covering the tip of the inner core. The tip portion of the inner core includes a plate-like portion formed in a thin plate shape, and the synthetic resin film is an upper layer and is made of a synthetic resin containing 70% by weight or more of an X-ray opaque material. A synthetic resin comprising the formed first synthetic resin layer and the second synthetic resin layer positioned between the first synthetic resin layer and the tip of the inner core, and forming the second synthetic resin layer Is a resin having higher rigidity than the first synthetic resin and does not contain an X-ray opaque material , and further, a resin forming the first synthetic resin layer and the second synthetic resin The resins forming the layers are both polyamide resins and both A medical wire, characterized in that it is a olefin resin, both are urethane resins, both are polyester resins, and both are vinyl chloride resins . The width of the plate-like portion is wider than the outer diameter of the inner core of the portion continuous with the plate-like portion, and the thickness of the plate-like portion is larger than the outer diameter of the inner core of the portion continuous with the plate-like portion. The medical wire according to any one of claims 1 to 3 , wherein the medical wire is thin. The medical wire according to any one of claims 1 to 4 , wherein the first synthetic resin layer contains 70 to 85% by weight of an X-ray opaque material. Distal portion of the inner core, the tapered portion reduced in diameter toward the distal end that is formed on the proximal side of the plate-like portion, either of claims 1 and a straight portion 5 which is continuous with the tapered portion Medical wire according to crab. The distal end portion of the inner core includes a first straight portion formed on the proximal side from the plate-like portion, a first tapered portion that is continuous with the first straight portion and has a diameter reduced toward the distal end. , a second straight portion continuous with the first tapered portion, contiguous with the second linear portion, and claims 1 and a second tapered portion which decreases in diameter toward the distal end 6 The medical wire according to any one of the above. The medical wire according to any one of claims 1 to 7 , wherein the medical wire is a guide wire for a catheter. The medical wire according to any one of claims 1 to 8 , wherein a substance having lubricity when wet is fixed on a surface of the synthetic resin coating.

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