JP3288619B2 - Guide wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guide wire used for introducing a catheter to a target site for treatment or examination.

[0002]

2. Description of the Related Art Conventionally, 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, and the distal end of the guide wire is advanced. The distal end of the guide wire reaches the target site, and then the catheter is guided to the target site.

In particular, percutaneous transluminal coronary angioplasty (PTC)
In A), while selecting a branch of a coronary artery under fluoroscopy, the coronary artery is allowed to reach a target stenosis part, pass therethrough, and then a dilatation catheter provided with a balloon at the distal end is guided along a guide wire. Then, the balloon of the dilatation catheter is positioned at the stenosis, and is expanded to expand the stenosis to secure blood flow, thereby treating angina pectoris and the like.

In order to advance the guide wire to a desired branch of the bifurcation of the coronary artery, the distal end of the guide wire is shaped (reshaped) to match the shape of the bifurcation.
Is performed by hand. In particular, when inserting into a peripheral coronary artery, a desired branch cannot be selected with a conventional preformed angle-type or J-type tip shape, and the guidewire tip must be reshaped and re-inserted. There are many. If the shape does not match, remove the guidewire from the catheter, reshape and insert.

[0005] Further, in order to direct the tip of the guide wire in a desired direction, it is important that a force for rotating the guide wire is transmitted to the tip. Also, X to perform those operations
The position of the tip of the guide wire is confirmed by irradiating a line, and a contrast agent is intermittently injected into the coronary artery to visually recognize an X-ray image of the coronary artery. Therefore, the tip of the guide wire is desired to have excellent X-ray contrast.

Furthermore, in order to insert a guide wire from the femoral artery and advance the aorta, aortic arch, and coronary artery into the coronary artery, the force for pushing the hand portion is transmitted to the distal end portion together with the flexibility for following the blood vessel. It is necessary. Furthermore, in order for the balloon of the dilatation catheter to be positioned at the stenosis (or occlusion) and expanded, it is important that the distal end of the guide wire pass through the stenosis. When the distal end of the guidewire is passed through such a narrowed or closed part, the guidewire is pushed in while rotating slowly, so that the rotation of the distal end of the guidewire is also synchronized with the rotation of the hand. If intermittent rotation (so-called splashing) occurs at the distal end with respect to the rotation at a constant speed at hand, it becomes difficult to pass through the stenosis.

As this type of guide wire, there are those disclosed in JP-A-59-77866 and JP-A-2-180277. In the former guide wire, the distal end portion of the main wire member is tapered in diameter toward the distal end, and a spring member is fixed only to that portion. The latter guide wire has a tapered inner core end and a high X-ray contrast part provided at the foremost end thereof.

[0008]

However, Japanese Unexamined Patent Publication No.
Once reshaped, the guide wire disclosed in 77866 becomes difficult to reshape. That is, the main wire member is plastically deformed by the reshaping, and it is difficult to reshape the main wire member into another shape, and it is necessary to prepare a new guide wire. Further, the spring member at the tip is exposed, and the unevenness on the surface becomes a resistance to the passage of the constriction. Especially when the constriction is smaller and smaller than the outer diameter of the guide wire tip, there is insertion resistance due to even slight surface irregularities. The more flexible the tip is, the easier it is to bend and the more difficult it is to pass due to the insertion resistance of the spring member. Become.

Further, the guide wire disclosed in Japanese Patent Application Laid-Open No. 2-180277 has a spring member having high X-ray contrast as the most advanced high X-ray contrast portion of the inner core.
This spring member is provided to ensure high X-ray contrast, and it is substantially difficult to reshape in dimension.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and is capable of performing reshaping, forming a desired shape even in a plurality of reshaping operations, having good visibility, and easily passing through a narrow portion. The purpose is to provide. It is still another object of the present invention to provide a guide wire capable of smoothly transmitting rotation at hand from the guide wire main body portion as torque to the distal end portion.

[0011]

Means for Solving the Problems To achieve such an object
For this purpose, the guide wire of the present invention comprises a main body,
Smaller diameter than bodyTip with almost uniform outer diameter
And a transition between the body and the tip
Core material, provided in close contact with the tip of the core materialPlastic deformation
DoAn X-ray contrast-enhancing metal coil, the core member and the contrast member
Synthetic resin coating overlaid to form a substantially smooth outer surface
A member, a hydrophilic lubricating layer covering the synthetic resin covering member,
It is composed of

Further, a guide wire according to the present invention is a super-elastic core material comprising a main body, a distal end having a smaller diameter than the main body, a transition portion between the main body and the distal end, A plastically deformable X-ray opaque metal coil provided in close contact with the tip of the material, a synthetic resin covering member that covers the core and the contrast member to form a substantially smooth outer surface, A hydrophilic lubricating layer covering the synthetic resin covering member, wherein the X-ray contrast
The axial length of the conductive metal coil is configured to be 10 to 40 mm .

Since the tip has a substantially uniform outer diameter, the tip has substantially the same flexibility in the axial direction. The tip is the most flexible part compared to the transition part and the main body.
The transition portion is a portion whose diameter is reduced from the base end toward the distal end. A taper-shaped tapered portion at a fixed ratio (also referred to as a tapered portion), a tapered portion whose diameter gradually changes, or a tip portion and a body portion that are easily bent by a synthetic resin covering member described later. Any configuration may be used as long as the rigidity properties of the distal end portion and the main body portion are not suddenly changed, such as a configuration in which the hardness is continuously or stepwisely changed. By providing the transition portion, bending (kinking) without local concentration of stress does not occur. The main body is a portion extending toward the proximal end of the transition portion, and is thicker than the distal end. this is,
This is to transmit the torque applied at hand or the axial force (pushing force) applied at hand to insert the guide wire to the tip as much as possible.

Each size of the core material differs depending on the use of the guide wire, but a PT having a tip portion, a transition portion, and a main body portion.
An example of the case of a CA guide wire is as follows. The outer diameter of the tip portion is 0.06 to 0.10 mm, the length is 10 to 50 mm, and the length of the transition portion is 50 to 60
0 mm. The outer diameter of the main body is 0.26 to 0.50 mm,
The length is 1000-3000 mm.

[0015] The core material may be composed of a tip transition portion and a main body. In this case, since the distal end transition portion is provided continuously from the main body, the diameter of the main body is reduced in a tapered shape from the same outer diameter as the main body having a constant outer diameter toward the distal end. The X-ray contrast member is provided at a predetermined distance from the front end transition portion. In addition, the core material may have a constant outer diameter from the distal end to the proximal end.

The core material is made of a super-elastic material having appropriate flexibility with blood vessel followability, transmitting torque to the distal end, and having rigidity for transmitting pushing force at hand to the distal end. As the superelastic material, Ni—Ti alloy, Cu—Zn—X alloy (X = Be, Si, Sn, A
1, Ga), a Ni-Al alloy, preferably Ni-
It is a Ti alloy. A third element such as Co or Fe may be added to the Ni-Ti alloy.

The superelastic core material may have the same physical properties at the tip, the transition portion and the main body, or may have different physical properties only at the tip. Further, the physical properties may be different only in the main body. For example, if the tip is made to have a physical property capable of being plastically deformed, the tip can be reshaped, but this can be achieved by deteriorating the superelastic properties by a predetermined heat treatment. The core body has a rigidity of 20 at 40 ° C.
It is preferable from the viewpoint of torque transmission that the heat treatment is performed so as to be 1.5 times or more the rigidity at ° C.

The X-ray contrast metal coil is provided in close contact with the tip of the superelastic core material. Gold, platinum, silver, bismuth, tungsten, alloys of two or more of these (for example, platinum-tungsten), or alloys with other metals (for example, gold-
Iridium, platinum-iridium) and the like. Another material may be plated on the surface of the contrast member. The outer diameter of the metal coil is not particularly limited as long as it satisfies the reshaping property, the operability of the guide wire, and the X-ray contrast property described later, but the larger the outer diameter of the contrast member, the better the X-ray contrast property. Further, torque transmission is facilitated when the outer diameter of the metal coil is equal to or smaller than the outer diameter of the core material. In the case of the core material having the three portions of the tip, the transition portion, and the main body as described above, the outer diameter of the imaging member is equal to or smaller than the outer diameter of the main body having the largest outer diameter. The axial length of the metal coil has a length that can be reshaped, and
40 mm is preferred.

The X-ray opaque metal coil and the core material can be adhered by winding the X-ray opaque metal wire around the core material,
It is possible to prepare an X-ray opaque metal coil having an inner diameter substantially equal to the outer diameter of the core material in advance, and insert the core material tip into the metal coil. It is preferable that both ends of the metal coil be fixed to the core material with an adhesive or soldering. Alternatively, both ends of the metal coil may be melted and fixed to the core material. Further, if the tip of the core material is formed as a bulged portion, such as a sphere, larger than the inner diameter of the metal coil, and the tip of the metal coil is abutted and fixed, the fixing can be performed more reliably. The spherical bulging portion is preferably formed by melting the core material so that it can be integrally formed with other portions of the core material.

By providing the superelastic core material in close contact with the X-ray opaque metal coil, reshaping is possible by plastic deformation of the metal coil. However, since the core material is superelastic, it is not plastically deformed, and can be returned to a straight shape or another shape only by changing the shape of the metal coil.

The X-ray opaque metal coil adhered to the core material is covered with a synthetic resin covering member from the outside. The covering member may cover only the metal coil and its periphery. That is, the front end of the synthetic resin covering member having the front end and the base end is located closer to the front end than the metal coil front end,
The proximal end terminates on the proximal side from the coil proximal end. In this case, it is preferable to apply silicone to the core material where there is no covering member.

The covering member made of synthetic resin is intended to cover the core material and the X-ray opaque metal coil to form a substantially smooth outer surface. The outer diameter of the guide wire covered by the coating member is preferably substantially uniform from the distal end to the proximal end. The distal end portion may have a smaller outer diameter than the other portions in order to allow the portion to pass therethrough or to be inserted into the microvessels. Further, only the leading end may be covered with a synthetic resin covering member.

The covering member is preferably made of a synthetic resin because of its ease of covering and the ease of treating the outer surface described later. The covering member made of synthetic resin is flexible enough not to hinder the bending of the core material, and the outer surface is a smooth surface having substantially no irregularities. It is also possible to mix a fine powdery X-ray contrast material into the synthetic resin forming the synthetic resin covering member. Examples of the fine powder X-ray contrast material include tungsten, bismuth, and barium.
The entire or a part of the guide wire can be visually recognized by coating a part or the entire surface of the core material with the covering member made of the synthetic resin containing the X-ray contrast material. In particular, the visibility is further improved by applying a covering member made of a synthetic resin containing an X-ray contrast material to the distal end portion of the guide wire.

Further, the flexibility of the covering member made of synthetic resin may be changed according to the flexibility of the core material. That is, the material is changed according to the respective portions of the core material having the tip portion, the transition portion, and the main body portion. For example, select the most flexible material at the tip because it may be inserted into the blood vessel and come into contact with the vessel wall, and the body is more rigid to reinforce the torsional and bending stiffness of the core itself. Material with high quality can be selected. It is possible to select an intermediate rigid material for the transition. Further, it is preferable to continuously change two kinds of resins having different stiffness so that the distribution of the resin having low stiffness increases as going to the front end, because the change in torsional stiffness does not become extreme.

Further, the covering member made of synthetic resin may have two or more layers. For example, the main body of the core material is coated with a resin having relatively high rigidity such as polyimide to impart rigidity, and the outer layer has a resin having a large number of reactive groups to which a hydrophilic lubricating layer described later is easily fixed. This means that a layer is provided and a lubricating layer such as a hydrophilic material is fixed to the resin layer. Further, in order to enhance the adhesiveness between the superelastic core material and the resin and improve the torque transmission, an adhesive resin such as an ionomer is used as an inner layer, and a lubricating layer having many reactive groups is fixed to the outer layer. Can be provided. Further, a low friction resin may be provided outside the covering member. Examples of the low friction resin include a fluorine resin.

Examples of the material of the synthetic resin covering member include polyurethane, polyethylene, polyvinyl chloride, polyester, polypropylene, polyamide, polystyrene, fluororesin, silicone or their respective elastomers (eg, polyester elastomers) and composite materials thereof. It can be suitably used.

The hydrophilic lubricating layer which covers the synthetic resin covering member exhibits hydrophilicity when wet and improves lubricity, and reduces frictional resistance with the inner surface of the catheter and blood vessels, thereby improving sliding. Sex can be obtained. Such a lubricating layer only needs to be fixed to the synthetic resin covering member, and may be fixed by a physical bond in addition to a chemical bond such as an ionic bond or a covalent bond. The hydrophilic lubricating layer fixed to the covering member is formed of a hydrophilic lubricating substance, and is preferably a water-soluble polymer substance. Also, the hydrophilic lubricating substance is
It is preferable to use a material which exhibits lubricity by containing water when wet. Further, the hydrophilic lubricating layer may be formed only at the tip portion of the guide wire.

As the hydrophilic lubricating substance, -OH, -CON
^{_{H 2, -COOH, -NH 2,}} -COO -, -SO 3-
Preferred are those having a hydrophilic group such as maleic anhydride, specifically, methyl vinyl ether maleic anhydride copolymer, methyl vinyl ether maleic anhydride sodium, methyl vinyl ether maleic anhydride ammonium salt, anhydride As the maleic acid ethyl ester copolymer, polyalkyne oxide is preferably polyethylene oxide, polyalkylene glycol is polyethylene glycol, and acrylic acid is sodium polyacrylate.

Further, it is desirable that the hydrophilic lubricating layer is a copolymer of a hydrophilic compound and a hydrophobic compound. Further, a block copolymer of a hydrophilic compound and a hydrophobic compound is desirable. Examples of such a block copolymer of a hydrophilic compound and a hydrophobic compound include polyglycidyl methacrylate (PGMA) -dimethylacrylamide (DMAA), methacrylic acid chlorido DMAA, methacryloyloxyethyl isocyanate-DMAA, polyglycidyl acrylate-maleic anhydride, and the like. is there.
The hydrophobic compound reacts and bonds with the coating member as the base material, and the hydrophilic compound swells with water to realize low friction.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a guide wire according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a first embodiment of the guide wire of the present invention, and FIG. 2 is a cross-sectional view showing a distal end portion of the embodiment of FIG.

As shown in FIG. 1, the guide wire 1 according to the first embodiment of the present invention includes a main body 12, a distal end 14 having a smaller diameter than the main body 12, and a main body 12 and a distal end 14. A superelastic core material 10 including a transition portion 16 between the core material, an X-ray opaque metal coil 20 provided in close contact with the tip end portion 14 of the core material 10, and substantially covering the core material 10 and the metal coil 20. It is composed of a synthetic resin covering member 30 that forms a smooth external surface, and a hydrophilic lubricating layer 40 that covers the synthetic resin covering member 30.

The guide wire 1 of the present invention has a total length of 180
cm and the outer diameter is about 0.35 mm. Guide wire 1
Can be applied in the range of 80 to 500 cm in total length, and the outer diameter varies depending on the application.
mm or less is preferable.

The superelastic core 10 has a tip 14 and a transition 1
6 and a main body 12. The distal end portion 14 has a substantially uniform outer diameter, and has substantially the same flexibility, and is the portion having the highest flexibility as compared with a later-described transition portion 16 and the main body portion 12. The outer diameter of the tip portion 14 of the core material 10 is about 0.1 mm, and the length is 20 mm. The transition portion 16 is a portion whose diameter is reduced from the base end toward the distal end, and is tapered at a constant rate in the present embodiment, and can be referred to as a tapered portion. Transition section 16 length 300m
m. By having the transition portion 16, the flexibility (flexibility) of the main body portion 23 and the distal end portion 21 having different outer diameters can be increased toward the distal end, that is, the flexibility can be increased, and the flexibility can be rapidly changed. The flexibility is continuously increased toward the tip and does not locally bend (kink). The main body 12 is
It is a portion extending toward the base end of the transition portion 16 and has an approximately uniform outer diameter of about 0.3 mm and a length of about 1500 mm.
The body 12 is thicker than the tip 14. This is for transmitting to the distal end portion 14 the torque applied at hand and the axial force (pushing force) applied at hand to insert the guide wire 1.

The distal end portion 14, the transition portion 16 and the main body portion 12 of the core material 10 are formed of the same material and are integrated. It is preferable to use an integral body without breakage or breakage. Such a superelastic core material 10 is a Ni-Ti alloy wire which is a superelastic alloy.
Since it is a superelastic alloy wire, it does not have a bending habit, and even if a torque is applied in a state where a meandering blood vessel is inserted, the force is smoothly transmitted to the distal end, and the torque transmission is rich.

FIG. 4 shows a load-strain curve of the superelastic core material 10 in a tensile test. Core material diameter is 0.343mm and 40 ℃
5% of the core material was subjected to a tensile test. The solid line is a load-strain curve of the core material 10 in the present embodiment, and the broken line is
It is a reference example in the same superelastic wire. As shown in FIG. 4, the yield load and the restoring load of the core material 10 are lower than those of the core material of the reference example. Further, in the core material 10, the yield point is not curved, and when the elastic region straight line reaches the yield point, the angle is changed to a superelastic region straight line, and the elastic region is widened. Such a core material 10 is achieved by performing a heat treatment at 450 to 550 ° C. for about 30 seconds to 2 minutes.

FIG. 5 is a diagram showing the torque transmission of the superelastic core material 10. A PVC tube with an inner diameter of 6 mm is used with a curvature of 30.
mm of U-shape, filled with water at 20 ° C., and the base rotation angle when the base of a 0.5 mm outer diameter NiTi wire (super elastic core material) was rotated at 1.5 rpm It shows the tip rotation angle (vertical axis) with respect to the (horizontal axis).
The broken line is an ideal line where the base rotation angle and the tip rotation angle are the same. FIG. 5A shows the result of the heat treatment, and FIG.
(B) is unprocessed. It can be seen that the untreated core material has a maximum difference of about 45 degrees with respect to the ideal line, whereas the heat-treated superelastic NiTi wire rotates almost along the ideal line. This means that the rotation at hand is smoothly transmitted to the tip without any rebound.

FIG. 6 is a diagram showing the rigidity of the superelastic core material 10. An untreated NiTi wire (A) and a heat-treated (B) having an outer diameter of 0.5 mm were prepared, and a load was applied to the center of a 25 mm span in a warm bath, and the wire was pushed down by 2 mm (5 mm / min). Was measured. According to FIG. 6, the rigidity was almost unchanged at 20 ° C.
The heat-treated one has a high rigidity, 40 ° C
It can be seen that the stiffness at 1.5 ° C. is 1.5 times or more that at 20 ° C. This is because the stiffness is high in the part introduced into the blood vessel near the body temperature, and the torque transmission and pushability are improved.

An X-ray opaque metal coil 20 is provided in close contact with the tip portion 14 of the superelastic core material 10. The X-ray contrast metal coil 20 is formed of gold, and the length of the metal coil 20 in the axial direction is 20 mm. Metal coil 20
Has a wire diameter of about 0.1 mm, is wound tightly around the core material 10, and the gap between the coils 20 is provided substantially closely. The outer diameter of the metal coil 20 provided at the distal end portion 14 of the core 10 is substantially the same as the outer diameter of the main body 12 of the core 10. At the distal end and the proximal end of the metal coil 20, fixing portions 22 for fixing to the distal end portion 14 of the core material 10 are provided. The fixing portion 22 uses an adhesive.

The covering member 30 made of synthetic resin is composed of the core material 10 and X
The lineable metal coil 20 is coated to form a substantially smooth outer surface. The outer diameter of the guide wire 1 covered by the covering member 30 is substantially uniform from the distal end to the proximal end. The covering member 30 is made of a synthetic resin because of its easiness of covering and easiness of treatment of an outer surface to be described later. The covering member 30 is flexible enough not to hinder the bending of the core material 10, and the outer surface is substantially uneven. Has no smooth surface. The coating material 30 covers the outer surface of the metal coil 20 which is substantially in close contact with the metal coil 20 and regulates the movement of the coil 20. Since the coil 20 and the core member 10 are not fixed except at both ends of the coil 20, it can be moved to some extent. As the synthetic resin, a thermoplastic resin is preferable because of its simple production. Polyurethane is used as the covering member 30 of the guide wire 1.

Further, the synthetic resin forming the synthetic resin covering member 30 contains 45% by weight of tungsten as an X-ray contrast material. By covering the surface of the core material 10 with the covering member 30 made of synthetic resin containing an X-ray contrast material, the whole or a part of the guide wire can be visually recognized.

The hydrophilic lubricating layer 40 is made of the synthetic resin covering member 3.
0 outer surface. If the entire outer surface of the covering member 8 is used, the inside of the blood vessel can be easily advanced, and the sliding property with the lumen in the catheter can be enhanced. In particular, when the purpose is to pass through a constricted portion, the hydrophilic lubricating layer 40 may be formed only at the tip portion.

Examples of the lubricating substance forming the lubricating layer 40 include polyalkylene glycols such as polyvinyl alcohol and polyethylene glycol, and maleic anhydrides such as a methyl vinyl ether-maleic anhydride copolymer. On the outer surface of the synthetic resin covering member 30, in addition to the hydrophilic lubricating layer 40, an anticoagulant such as heparin, urokinase or silicone rubber, a block copolymer of urethane and silicone, a hydroxyethyl methacrylate-styrene copolymer And other antithrombotic materials.

FIG. 2 is a sectional view showing a second embodiment of the guide wire according to the present invention. 1 are indicated by the same reference numerals. The guide wire 11 shown in FIG. 2 includes a superelastic core material 10 including a main body 12, a distal end portion 14 having a smaller diameter than the main body portion 12, and a transition portion 16 between the main body portion 12 and the distal end portion 14. An X-ray opaque metal coil 20 provided in close contact with the distal end portion 14 of the core material 10, a core material 10 and a metal coil 2
It is composed of a synthetic resin covering member 30 that forms a substantially smooth outer surface by covering 0, and a hydrophilic lubricating layer 40 that covers the synthetic resin covering member 30. Furthermore, the tip 1
At the forefront of No. 4, a bulging portion 14a is formed.

The guide wire 1 of the present invention has a total length of 180.
cm and the outer diameter is about 0.35 mm. Guide wire 1
Can be applied in the range of 80 to 500 cm in total length, and the outer diameter varies depending on the application.
mm or less is preferable.

The superelastic core material 10 includes the main body 12, the transition 1
6. Tip 14 and tip end bulge 14 at tip 14
a. The distal end portion 14 has a substantially uniform outer diameter, and has substantially the same flexibility.
This is the portion having the highest flexibility compared to 2. The outer diameter of the tip portion 14 of the core material 10 is about 0.08 mm, and the length is 20 mm. The bulging portion 14a has a spherical shape, and is formed by dissolving the core material 10 into a spherical shape. The diameter of the bulging portion 14a is larger than the inner diameter of the metal coil 20 described later, and is larger than the outer diameter of the tip portion 14, so that the metal coil 20 can be securely fixed to the core material 10. The bulging portion 14 is formed by inserting the coil 20 into the core material 10 and melting the protruding core material 10. The transition portion 16 is a portion whose diameter is reduced from the base end toward the distal end, and is tapered at a constant rate in the present embodiment, and can be referred to as a tapered portion. The length of the transition portion 16 is 300 mm. The main body 23 and the tip 21 having different outer diameters by having the transition portion 16
The bendability (flexibility) can be increased as it goes to the tip, that is, it can be made softer, the bendability does not change suddenly, and the flexibility increases continuously as it goes to the tip, It does not bend (kink) locally. The main body portion 12 is a portion extending to the proximal end side of the transition portion 16 and has an outer diameter that is substantially uniform and is approximately 0.3 m.
m, about 1500 mm long. The body 12 is thicker than the tip 14. This is to transmit to the distal end portion 14 the torque applied at hand and the axial force (pushing force) applied at hand to insert the guide wire 1.

The bulge portion 14a, the tip portion 14, the transition portion 16, and the main body portion 12 of the core material 10 are integrally formed of the same material. It is preferable to use an integral body without breakage or breakage.
Such a superelastic core material 10 is made of Ni-T which is a superelastic alloy.
This is an i-alloy wire. Since it is a superelastic alloy wire, it does not have a bending habit, and even if a torque is applied in a state where a meandering blood vessel is inserted, the force is smoothly transmitted to the distal end, and the torque transmission is rich. An X-ray opaque metal coil 20 is provided in close contact with the distal end portion 14 of the superelastic core material 10. The X-ray contrast metal coil 20 is formed of an alloy of 92% platinum and 8% iridium, and has appropriate rigidity as well as X-ray contrast. With appropriate rigidity, shape retention during plastic deformation is possible, and it is easy to form a guide wire tip at a desired shape. The axial length of the metal coil 20 is 20 mm.
The wire diameter of the metal coil 20 is about 0.1 mm.
The coils 20 are wound in close contact with each other, and the intervals between the coils 20 are provided substantially in close contact with each other. Tip 14 of core material 10
The outer diameter of the metal coil 20 provided in the core member 10 is smaller than the outer diameter of the main body 12 of the core member 10. At the distal end and the proximal end of the metal coil 20, fixing portions 22 for fixing to the distal end portion 14 of the core material 10 are provided. The fixing portion 22 uses an adhesive.

The covering member 30 made of synthetic resin is made of the core material 10 and X
The lineable metal coil 20 is coated to form a substantially smooth outer surface. The outer diameter of the guide wire 1 covered by the covering member 30 is substantially uniform from the distal end to the proximal end. The covering member 30 is made of a synthetic resin because of its easiness of covering and easiness of treatment of an outer surface to be described later. The covering member 30 is flexible enough not to hinder the bending of the core material 10, and the outer surface is substantially uneven. Has no smooth surface. The coating material 30 covers the outer surface of the metal coil 20 which is substantially in close contact with the metal coil 20 and regulates the movement of the coil 20. Since the coil 20 and the core member 10 are not fixed except at both ends of the coil 20, it can be moved to some extent. As the synthetic resin, a thermoplastic resin is preferable because of its simple production. As the covering member 30, methacrylic acid modified polyethylene is used.

Further, the synthetic resin forming the synthetic resin covering member 30 contains 45% by weight of tungsten as an X-ray contrast material. By covering the surface of the core material 10 with the covering member 30 made of synthetic resin containing an X-ray contrast material, the whole or a part of the guide wire can be visually recognized.

The hydrophilic lubricating layer 40 is made of the synthetic resin covering member 3.
0 outer surface. If the entire outer surface of the covering member 8 is used, the inside of the blood vessel can be easily advanced, and the sliding property with the lumen in the catheter can be enhanced. In particular, when the purpose is to pass through a constricted portion, the hydrophilic lubricating layer 40 may be formed only at the tip portion. The lubricating substance forming the lubricating layer 40 is a block copolymer of polyglycidyl methacrylate (PGMA) -dimethylacrylamide (DMAA), which is a block copolymer of a hydrophilic compound and a hydrophobic compound.

On the outer surface of the synthetic resin covering member 30, in addition to the hydrophilic lubricating layer 40, an anticoagulant such as heparin or urokinase or silicone rubber, a block copolymer of urethane and silicone, hydroxyethyl methacrylate-styrene An antithrombotic material such as a copolymer may be coated.

FIG. 3 is a sectional view showing a second embodiment of the guide wire according to the present invention. 1 are indicated by the same reference numerals. The guide wire 100 shown in FIG. 3 includes a superelastic core material 10 including a main body 12, a distal end portion 14 having a smaller diameter than the main body portion 12, and a transition portion 16 between the main body portion 12 and the distal end portion 14. An X-ray opaque metal coil 20 provided in close contact with the distal end portion 14 of the core member 10, and a synthetic resin covering member that covers the core member 10 and the metal coil 20 to form a substantially smooth outer surface 30 and a hydrophilic lubricating layer 40 that covers the synthetic resin covering member 30. Furthermore, core material 1
The tip 14 has physical properties capable of maintaining a deformed shape at room temperature or near body temperature.

The guide wire 1 of the present invention has a total length of 180
cm and the outer diameter is about 0.35 mm. Super elastic core material 10
Consists of a main body 12, a transition portion 16, and a tip portion 14. The distal end portion 14 has a substantially uniform outer diameter, and has substantially the same flexibility, and is the portion having the highest flexibility as compared with a later-described transition portion 16 and the main body portion 12. The outer diameter of the tip portion 14 of the core material 10 is about 0.08 mm, and the length is 20 mm.

FIG. 6 shows a load-strain curve of the core material 10 used for the tip portion 14 by a tensile test. The core diameter is approx.
The core material was subjected to a 5% tensile test at 335 mm and 40 ° C. It can be seen that when unloading is performed after 5% load, about 1.8% strain remains. The distal end portion 14 can be reshaped with fingers.

The transition portion 16 is a portion whose diameter is reduced from the base end toward the tip end, and in this embodiment, is tapered at a constant rate in this embodiment, and can be called a tapered portion. . The length of the transition portion 16 is 300 mm. By having the transition portion 16, the flexibility (flexibility) of the main body portion 23 and the distal end portion 21 having different outer diameters can be increased toward the distal end, that is, the flexibility can be increased, and the flexibility can be rapidly changed. The flexibility is continuously increased toward the tip and does not locally bend (kink). The main body portion 12 is a portion extending toward the base end side of the transition portion 16 and has an outer diameter that is substantially uniform, about 0.3 mm, and about 1500 mm in length. The body 12 is thicker than the tip 14. This is to transmit to the distal end portion 14 the torque applied at hand and the axial force (pushing force) applied at hand to insert the guide wire 1.

The front end portion 14, the transition portion 16 and the main body portion 12 of the core member 10 are integrally formed of the same material. It is preferable to use an integral body without breakage or breakage. Such a superelastic core material 10 is a Ni-Ti alloy wire which is a superelastic alloy.
Since it is a superelastic alloy wire, it does not have a bending habit, and even if a torque is applied in a state where a meandering blood vessel is inserted, the force is smoothly transmitted to the distal end, and the torque transmission is rich.

An X-ray opaque metal coil 20 is provided in close contact with the tip portion 14 of the superelastic core material 10. The X-ray contrast metal coil 20 is formed of an alloy of 92% platinum and 8% iridium, and has appropriate rigidity as well as X-ray contrast. With appropriate rigidity, shape retention during plastic deformation is possible, and it is easy to form a guide wire tip at a desired shape. The axial length of the metal coil 20 is 20 mm. The wire diameter of the metal coil 20 is about 0.1 mm, the metal coil 20 is wound tightly around the core material 10, and the gap between the coils 20 is provided substantially closely. The outer diameter of the metal coil 20 provided at the distal end portion 14 of the core 10
Has an outer diameter smaller than that of the main body 12. Metal coil 20
A fixing portion 22 for fixing to the distal end portion 14 of the core member 10 is provided at the distal end portion and the proximal end portion of the core member 10. The fixing portion 22 uses an adhesive. The synthetic resin covering member 30 and the hydrophilic lubricating layer 40 are the same as those in the first embodiment.

[0057]

The operation of the guide wire of the present invention will be described with reference to the example of PTCA.

First, the guiding catheter is advanced to the ostium of the coronary artery via the aorta, and a contrast medium is discharged from the tip of the guiding catheter to perform coronary angiography in order to confirm a target portion of the coronary artery having a stenosis. Next, the guide wire of the present invention is inserted into the guide wire lumen of the dilatation catheter provided with a balloon for dilating the stenosis at the distal end to prepare the balloon. At this time, in order to reach the target blood vessel, the distal end of the guide wire is reshaped into a shape suitable for the blood vessel bifurcation. Since the guide wire of the present invention is provided with a metal coil that is plastically deformed on a superelastic core material having no or little bending habit, the force for maintaining the shape of the metal coil is superior, and the desired shape (for example, when the tip 5 mm is formed). (Shape of about 60 degrees).

The dilatation catheter into which such a guide wire has been inserted is inserted into the guiding catheter. When the distal end of the guiding catheter is reached, the insertion of the dilatation catheter is stopped, and only the guide wire is pushed into the coronary artery while performing appropriate imaging. Since the guide wire of the present invention is provided with the X-ray contrast metal coil at the tip of the core material, the tip of the guide wire can be easily confirmed under X-ray contrast.

When it is difficult to insert into a predetermined blood vessel bifurcation, or when it is desired to select another branch, the guide wire can be once removed from the catheter and reshaped again. Since the guide wire of the present invention has a core material that is superelastic and has no or little bending habit, it can be changed to another shape only by plastic deformation of the metal coil.
That is, reshape can be repeated. The synthetic resin covering member covers the outer surface of the metal coil, and the metal coil and the core material are not fixed except at both ends of the metal coil. Therefore, when the tip of the guide wire is bent to reshape, the covering member tries to suppress the movement of the coil, but once it is bent with a finger or a tool for further shaping, the outside of the curve is bent. The distance between the coils is increased, and the inner side moves so as to slightly overlap, and the shape is maintained by plastic deformation of the coil itself and elasticity of the covering member. Further, since the metal coil and the core material are in close contact with each other, the force is easily transmitted to the core material. Once attached, the shape facilitates selection of the desired blood vessel without being reinserted into the catheter.

After the guide wire has reached the stenosis, it is easy to pass through the stenosis if the guide wire is pushed forward while rotating at the tip thereof. Therefore, it is necessary to slowly press it at hand while pushing it in. The superelastic core material body with good torque transmission, a synthetic resin covering member that forms a substantially smooth outer surface, and hydrophilic lubrication of the outer surface By providing the layer with lubricity, the smooth rotation of the hand becomes almost the smooth rotation of the tip, so that the guide wire tip does not rebound and the passage of the constriction becomes easy.

Next, by pushing the dilatation catheter along the guide wire, confirming that the balloon of the dilatation catheter is at the center of the stenosis, injecting and pressurizing a contrast medium into the balloon to expand the balloon. Dilate the stenosis.
After the dilation is completed, the dilatation catheter is withdrawn and the process is terminated.

The guide wire of the present invention is a PTC
In addition to A, it can be used for catheterization for angiography and treatment of the brain and abdomen.

[0064]

The guide wire according to the present invention comprises a main body,
A superelastic core comprising a tip portion having a diameter smaller than that of the main body portion, a transition portion between the main body portion and the tip portion, and an X-ray contrast property provided in close contact with the tip portion of the core material. A metal coil, a synthetic resin covering member that covers at least a part of the contrastable metal coil and the core material to form a substantially smooth outer surface, and at least a part of the synthetic resin covering member Since it is composed of a hydrophilic lubricating layer covering the surface, reshaping is possible, and a desired shape can be formed even in a plurality of reshapings, visibility is good, and a narrow portion can be easily passed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of a guide wire according to the present invention.

FIG. 2 is a sectional view showing a second embodiment of the guide wire of the present invention.

FIG. 3 is a cross-sectional view showing a third embodiment of the guide wire of the present invention.

FIG. 4 is a diagram showing a load-strain curve by a tensile test of a superelastic core material of the guide wire of the present invention.

FIG. 5 is a diagram showing torque transmission of a superelastic core material of the guide wire of the present invention.

FIG. 6 is a diagram showing the rigidity of the superelastic core material of the guide wire according to the present invention.

FIG. 7 is a diagram showing a load-strain curve by a tensile test of a core material used for a distal end portion in a third embodiment of the guide wire of the present invention.

[Explanation of symbols]

 Guide wire 1 Superelastic core material 10 Main body part 12 Tip part 14 Transition part 16 X-ray opaque metal coil 20 Synthetic resin covering member 30 Hydrophilic lubricating layer 40

Claims (4)

(57) [Claims] 1. A body, a tip having a smaller diameter than the body and having a substantially uniform outer diameter, and a tapered transition between the body and the tip . A superelastic core material comprising: a core, a plastically deformable X-ray opaque metal coil provided in close contact with the tip of the core material, and at least a part of the opaque metal coil and the core material. A guide wire comprising: a synthetic resin covering member that forms a substantially smooth outer surface; and a hydrophilic lubricating layer that covers at least a part of the synthetic resin covering member. 2. A super-elastic core material comprising a main body, a tip portion smaller in diameter than the main body portion, and a transition portion between the main body portion and the tip portion, and in close contact with the tip portion of the core material. A plastically deformable X-ray opaque metal coil, and a synthetic resin covering member that forms at least a part of the opaque metal coil and the core material to form a substantially smooth outer surface, A hydrophilic lubricating layer covering at least a part of the synthetic resin covering member, wherein the X-ray contrast-enhancing metal coil has an axial length of 10 to 40.
mm. 3. The guide wire according to claim 1, wherein the hydrophilic lubricating layer is formed only at a tip portion of the guide wire. 4. The rigidity of the core material at 40 ° C. is 20 ° C.
The guidewire according to claim 1, wherein the guidewire has a rigidity of 1.5 times or more.