JPH0344540B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a guide wire for a catheter for introducing a therapeutic or testing catheter into a target site in the body such as a blood vessel or a gastrointestinal tract.

[Prior Art] Conventionally, as guide wires for catheters, guide wires using a coil spring made of stainless steel wire or piano wire, and guide wires using a plastic monofilament have been used. There are two types of guide wires: one with a straight tip and one with a J-shaped tip.

After the guide wire is inserted into the blood vessel along with the catheter, in order to reach the target blood vessel site, the guide wire is placed in front of the catheter by protruding a predetermined length from the tip of the catheter. Push forward. Therefore, the tip of the guide wire is required to be flexible enough to be inserted into meandering blood vessels and complicated blood vessel branches without damaging the blood vessel wall.

However, the above-mentioned guide wire does not have sufficient flexibility or restorability because its distal end portion is made of a general metal material or plastic.

Therefore, the applicant has proposed a guide wire that solves the above problems (Japanese Patent Application Laid-open No. 1983-
63065, Japanese Patent Application Laid-open No. 60-63066).

[Problems to be Solved by the Invention] The above-mentioned guide wire has sufficient flexibility and restorability, but a straight guide wire can be used satisfactorily for patients with less meandering of the aorta, and generally younger patients. In elderly patients, patients with large tortuous aortas, and patients with a large amount of cholesterol, etc. deposited in the arterial blood vessels, it may be difficult to insert a guide wire with a straight tip as described above. A curved guide wire was used.

However, the guide wire having a curved tip as described above has a problem in that it is difficult to insert it into the Seldinger needle that is punctured to insert the catheter into the femoral artery.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a catheter guide wire that has high flexibility and restorability, and allows easy insertion of a Seldinger needle even if the guide wire has a curved tip. .

[Means for solving the problem] What achieves the above purpose is a flexible tip,
In the catheter guide wire having a main body portion, the distal end portion is provided on the distal end side of the guide wire, and the martensitic reverse transformation start temperature is 0°C.
A shape-memory part made of a shape-memory alloy whose temperature is between 40°C and 40°C, and formed to transform into a curved shape at a temperature higher than the temperature, and a super-elastic part made of a super-elastic metal following the shape-memory part. A catheter guide wire characterized by having the following features.

The guide wire includes, for example, a metal core and a coil spring that encloses at least a distal end portion of the metal core. Furthermore, the shape memory portion is formed by, for example, the tip of the coil spring. Also,
The shape memory portion is formed, for example, by the tip of the metal core. Further, the coil spring includes, for example, a tip coil spring and a base coil spring continuous with the tip coil spring, and the shape memory portion is formed by the tip coil spring. . Furthermore, the superelastic portion is formed by, for example, the base coil spring. Furthermore, the core metal is, for example,
It has a tip core metal and a tip base core metal continuous with the tip core metal, and the shape memory portion is formed by the tip core metal. Furthermore, the tip of the core metal may be fixed to the tip of the coil spring. Further, the superelastic portion is formed by, for example, the tip base metal core. Further, the tip of the core bar is not fixed to the tip of the coil spring, and the core bar is fixed near a continuous portion of the tip coil spring and the base coil spring, and The shape memory portion may be formed by the tip coil spring, and the superelastic portion may be formed by a core metal located at a rear end side of a fixed portion between the core metal and the coil spring. good. Furthermore, the coil spring may cover the entire core metal. Furthermore, it is preferable that the core metal has a main body core metal continuing to the tip portion, and the tip portion has a smaller diameter than the main body core metal. moreover,
The guide wire includes, for example, a tip core metal forming the shape memory portion, a tip base core metal forming a superelastic portion continuous with the tip core metal, and a main body core continuous with the tip base core metal. It consists of a core metal having gold. Furthermore, the guide wire is
It is preferable that the outer surface be coated with a synthetic resin. Furthermore, it is preferable that the martensitic reverse transformation start temperature of the shape memory alloy forming the shape memory portion is 26°C to 36°C. Further, it is preferable that the tip core metal and the tip base core metal have a smaller diameter than the main body core metal.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The catheter guide wire of the present invention will be explained using embodiments shown in the drawings.

The catheter guide wire 1 of the present invention is a catheter guide wire having a flexible tip portion and a main body portion 4, and the tip portion is provided on the distal side of the guide wire, and the martensitic reverse transformation starting temperature is 0°C. A shape memory part 2 made of a shape memory alloy whose temperature is between 40°C and 40°C and transformed into a curved shape at a temperature higher than the above temperature, and a superelastic part 2 made of a superelastic metal following the shape memory part 2. It consists of part 3.

Therefore, an explanation will be given using the embodiment shown in FIG.

Catheter guide wire 1 shown in Fig. 1
has a shape memory section 2 provided in the direction of its tip;
It consists of a tip part formed by a superelastic part 3 that is continuous with the shape memory part 2, and a main body part 4 that is continuous with the superelastic part 3. Specifically, it is made of a shape memory alloy and is made of a shape memory alloy. The tip coil spring 5 forming the tip coil spring 5 , the superelastic core metal 6 made of a superelastic alloy fixed to the rear end of the tip coil spring 5 and forming the superelastic portion 3 , and the superelastic core metal 6 forming the superelastic portion 3 . The main body core bar 8 is connected to the rear end, the base end is fixed near the connection between the superelastic core bar 6 and the main body core bar 8, and the tip is continuous with the rear end of the tip coil spring 5. It consists of a base coil spring 7.

That is, in this embodiment, the tip of the superelastic core metal 6 does not reach the tip of the tip coil spring 5, and therefore the superelastic core metal 6 is fixed to the tip of the tip coil spring 5. The distal end portion of the guide wire 1 is formed only by the distal end coil spring 5.

The main body core bar 8 is connected to the main body 4 of the guide wire 1.
It is preferable that the main body part 4 has a function of reliably transmitting the operation at the proximal end (the hand at the time of use) to the distal end, and for this purpose, it is preferably formed of a material with high rigidity. preferable.
The bending rigidity is preferably 15 Kg/mm ² or more, preferably 18 Kg/mm ² or more. Stainless steel or the like is suitable as a material for the main body core bar 8, and high tensile strength stainless steel for springs is particularly suitable. By forming the guide wire from a material with high bending rigidity, when inserting the guide wire, when manipulating the tip to travel in the desired direction within a lumen such as a blood vessel, and when pushing the tip, In addition, the force generated when rotating the guide wire at the proximal end (proximal end) can be reliably transmitted to the distal end, making insertion easier.

The main body core bar 8 has a diameter of 0.1 to 1.8
mm, preferably 0.15-1.6mm, length 30mm-3500
mm, preferably 50 mm to 3000 mm.

The flexible part of the guide wire formed by the shape memory part 2 and the superelastic part 3 can be inserted into the meandering blood vessel,
It forms a guide part for advancing the guide wire through the narrowed blood vessel, and therefore,
It is necessary to have high flexibility, in other words to have a wide elastic region, and to have a curved portion at the tip.

Therefore, in this embodiment, the tip coil spring 5 forming the shape memory portion 2 is formed of a shape memory alloy whose martensitic reverse transformation start temperature is 0°C to 40°C, and is further higher than the above temperature as required. It is formed so that it transforms into a curved shape at high temperatures. As a shape memory alloy, Ni
- Formed from Ti-based alloys, Au-Cd-based alloys, Cu-Al-Ni-based alloys, Cu-Au-Zn-based alloys, Ni-Al-based alloys, etc., and furthermore, the martensite reverse transformation start temperature of the shape memory alloys. (The temperature at which the martensite phase begins to disappear and becomes the parent phase, the austenite phase) is 0°C to 40°C. Furthermore, this tip coil spring 5 is
It is formed into a curved shape, for example a J shape, at high temperature.
It remembers its curved shape. Then, by stretching it in a straight line in a cooled state, it becomes a straight line as shown in Figure 1, and by inserting it into a blood vessel and heating it, it restores to its memorized curved shape. do.

Shape memory alloys with a martensitic reverse transformation start temperature of 40°C or lower are used in approx.
Blood cell components and tissue cells are likely to be destroyed at 42°C, so heating the tip of the guidewire introduced into the blood vessel (e.g., high-frequency heating, heat transfer by heating the rear end of the guidewire) It is preferable that the limit at which the martensite transformation starts is 42°C, and if the martensitic reverse transformation start temperature is 40°C, the tip coil spring 5 can return to its curved shape at 42°C, which is 2°C higher than that temperature. It is. In other words, if the martensite reverse transformation start temperature is 40°C or lower, heating to 42°C will almost restore the memorized curved shape, so 40°C is 2°C lower than the 42°C that can be heated.
It was set as ℃.

Further, the reason why the temperature is set at 0°C or higher is that it is usually difficult to cool the temperature to 0°C or lower. When the martensitic reverse transformation start temperature is 0° C. to 26° C., the room temperature in the operating room is usually adjusted to about 25° C., so the curved shape is restored to the memorized shape at room temperature. For this reason, since it has a curved shape before being inserted into the blood vessel, that part (tip coil spring 5) is immersed in ice water or alcohol cooled with ice water to cool it and straighten the tip part. Use immediately. The martensite reverse transformation starting temperature is preferably 28°C to 36°C, and if it is 26°C or higher, there is little possibility that it will return to its curved shape depending on the room temperature in the operating room, as described above. There is no need to cool the blood or straighten it into a straight line.If it is below 36℃, the blood temperature is about 38℃, so by inserting it into the blood vessel, it will be warmed by the blood and will naturally memorize. Since it returns to its curved shape, there is no need to heat it from the outside.

The length of the tip coil spring 5 is 10
mm to 500 mm, preferably 20 mm to 300 mm.

The superelastic core metal 6 connected to the rear end of the tip coil spring 5 is made of a superelastic alloy, and the superelastic alloy has a tensile strain of 8
It is an alloy that has a wide elastic range that does not undergo plastic deformation even when the
Superelastic metals such as Ni-based alloys and Cu-Zn-Al-based alloys are suitable.

The tip of the tip coil spring 5 is
It has a hemispherical tip 9. A hemispherical tip means a substantially curved tip, and includes shapes such as a bell shape and a bullet shape.

It is preferable that the superelastic cored metal 6 is more flexible on the tip side, and in particular, it is preferable that the superelastic cored metal 6 becomes more flexible toward the tip. Therefore, in the embodiment shown in FIG. 6 has a gradually decreasing diameter, and by changing the diameter, the flexibility can be changed according to the application. Further, the flexibility can also be changed by changing the heat treatment conditions of the alloy forming the superelastic core metal 6.

The length of the superelastic core metal 6 is 50 mm to 10000 mm,
Preferably it is 100 mm to 800 mm.

The base coil spring 7 has the functions of preventing the distal end portion of the guide wire from buckling even in a bent vascular region, achieving uniformity of the outer diameter of the guide wire 1, and improving X-ray contrast properties. It is something that you have.

For the base coil spring 7, the wire diameter is 0.05~
0.2 mm stainless steel, platinum, platinum alloy, tungsten or palladium/silver alloy, etc. can be suitably used, especially platinum, platinum alloy, tungsten, or palladium alloy, such as palladium/silver alloy, etc., which have excellent X-ray contrast properties. By using the above-mentioned material, the position of the distal end within the blood vessel can be more easily confirmed during X-ray contrast imaging. The outer diameter of the base coil spring 5 is 0.2 to 1.8 mm, preferably 0.25 to 1.6 mm.
mm. And the base coil spring 7 is
It encloses a superelastic cored metal 6, and is fixed to the outer periphery of the tip portion of the superelastic cored metal 6 and the rear end of the tip coil spring 5 with wax 11 or the like, and the base end is
The superelastic cored metal 6 and the main body cored metal 8 are fixed near the connection portion with wax 12 or the like.

The superelastic cored metal 6 and the main body cored metal 8 can be connected by fitting the proximal end of the superelastic cored metal 6 to the tip of the main body cored metal 8, or by brazing the two together. A known method or a combination of both can be used. In particular, as shown in FIG. 1, a hole having an inner diameter equal to or slightly larger than the diameter of the proximal end of the superelastic cored metal 6 is provided at the tip of the main body cored metal 8, and a concave shape is formed in the hole on the circumference. It is preferable to insert the proximal end of the superelastic mandrel 6 having a groove and to fix the vicinity of the connecting portion between the two with the solder 12. By doing this, the two can be firmly connected.

In the above description, the superelastic part is formed by the superelastic cored metal 6, but the cored metal 6 is not limited to this.
The base coil spring 7 may be formed from a superelastic metal to form a superelastic part, and further, both the core bar 6 and the base coil spring 7 may be formed from a superelastic metal. Good too.

Furthermore, it is preferable to coat the outer surface of the main body core bar 8 with a lubricity agent 13 for reducing the frictional resistance with the inner surface of a cylindrical body such as a catheter. Preferably, it is on the order of microns.

As the lubricity imparting agent, water-soluble polymeric substances or derivatives thereof are preferable, such as poly(2-hydroxyethyl methacrylate), polyhydroxyethyl acrylate, cellulose-based polymeric substances (e.g., hydroxypropyl cellulose, hydroxyethyl cellulose). ), maleic anhydride-based polymeric substances (e.g., methyl vinyl ether maleic anhydride copolymer), acrylamide-based polymeric substances (e.g., polyacrylamide), polyethylene oxide-based polymeric substances (e.g., polyethylene oxide, polyethylene glycol), Polyvinyl alcohol, polyacrylic acid-based polymeric substances (e.g., sodium polyacrylate), phthalic acid-based polymeric substances (e.g., polyhydroxyethyl phthalate), water-soluble polyesters (e.g., polydimethylolpropionate), ketone aldehyde resins (e.g. methyl isopropyl ketone formaldehyde), folivinylpyrrolidone,
Polyethyleneimine, polystyrene sulfonate, water-soluble nylon, etc. can be used.

Furthermore, it is preferable to prevent the lubricity imparting agent from easily peeling off or flowing out. For example, a film of a compound having a reactive functional group is formed on the outer surface of the main body core bar 8, and a water-soluble polymeric material is formed on the outer surface of the main body core bar 8. It is preferred that the water-soluble polymer substance or its derivative be coated on the coating of the compound by ionic or covalent bonding of the compound or its derivative with the reactive functional group of the compound.

As water-soluble polymer substances or their derivatives,
The above-mentioned substances can be suitably used. Suitable reactive functional groups include isocyanate groups, amino groups, aldehyde groups, and epoxy groups. Therefore, as compounds having reactive functional groups and coating-forming properties, polyurethane, polyamide, etc. are preferable. suitable.

Furthermore, in order to increase the number of reactive functional groups, it is preferable to mix a substance having a reactive functional group into the above compound. Such substances include isocyanates such as ethylene diisocyanate, hexamethylene diisocyanate, xylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and adducts or prepolymers of these isocyanates and polyols, polyamines (e.g., low molecular weight polyamines, ethylene diamine, Examples include methylene diamine, high molecular weight polyamine) glutaraldehyde, etc. The coating method includes a substance having a reactive functional group [for example, a solution of polyurethane (tetrahydrofuran solution)] and a substance having a reactive functional group [for example, a solution of 4,4' diphenylmethane diisocyanate (a methyl ethyl ketone solution)]. ] to the mixture with the coated area (the first
After contacting the outer surface of the linear body 2) and drying it,
This can be carried out by contacting with a water-soluble polymer [for example, a solution of methyl vinyl ether maleic anhydride copolymer (methyl ethyl ketone solution)] and drying.

By doing so, lubricity can be imparted to the surface of the guide wire, and furthermore, the lubricity can be maintained for a long time.

Next, the catheter guide wire shown in FIG. 2 will be explained.

Catheter guide wire 1 shown in Fig. 2
consists of a shape memory part 2, a superelastic part 3 having a superelastic part continuous with the shape memory part 2, and a main body part 4 continuous with the superelastic part 3. To be more specific, A tip core metal 21 forming a shape memory portion 2 and a tip base core metal 22 forming a superelastic portion 3 having superelasticity that is continuous with the rear end of the tip core metal 21.
The main body core bar 8 is connected to the rear end of the tip base core bar 22, the base end is fixed near the connection between the tip base core bar 22 and the main body core bar 8, and the tip is connected to the tip base core bar 22. Coil spring 20 fixed to the tip of gold 21
It is made up of.

The main body core bar 8 is connected to the main body 4 of the guide wire 1.
It is preferable that the main body part 4 has a function of reliably transmitting the operation at the proximal end (the hand at the time of use) to the distal end, and for this purpose, it is preferably formed of a material with high rigidity. preferable.
As for the rigidity, it is preferable to have a bending rigidity of 15 Kg/mm ² or more, preferably 18 Kg/mm ² . Stainless steel or the like is suitable as a material for the main body core bar 8, and high tensile strength stainless steel for springs is particularly suitable.

The main body core bar 8 has a diameter of 0.1 to 1.8
mm, preferably 0.15-1.6mm, length 30mm-3500
mm, preferably 50 mm to 3000 mm.

The tip of the guide wire formed by the shape memory part 2 and the superelastic part 3 is inserted into the meandering blood vessel.
It forms a guiding part to allow the guide wire to easily advance into a blood vessel with a reduced diameter. Therefore, it must have high flexibility, in other words, it must have an elastic region, and its tip must have a curved shape. It is necessary to have a section.

Therefore, in this embodiment, the tip core metal 21 in the shape memory section 2 is formed of a shape memory alloy whose martensitic reverse transformation start temperature is 0°C to 40°C, and furthermore, at a temperature higher than the above temperature. It is formed to transform into a curved shape. The martensitic reverse transformation initiation temperature is preferably 26°C to 36°C.

The tip core bar 21 has a length of 10 mm to 100 mm,
Preferably it is 15 mm to 70 mm.

The tip base core metal 22, which is continuous with the rear end of the tip core metal 21, is made of a superelastic alloy, and a superelastic alloy is an alloy that has a wide elastic region that does not undergo plastic deformation even under a tensile strain of about 8%. It is.

In this embodiment, the tip core metal 21 forming the shape memory portion 2 and the tip base metal core 22 forming the superelastic portion 3 are integrally molded.

Examples of materials forming the tip core metal and the tip base core metal include Ni-Ti alloy, Cu-Al-Ni
Cu-Zn-Al alloys, Cu-Zn-Al alloys, etc. can be suitably used.

As described above, the method for forming the core metal in which the tip portion becomes the shape memory portion and the subsequent portion becomes the superelastic portion is to form the tip core metal 21 and the tip base core metal using the alloy as described above. A linear body of the required length is formed as 22, and first, the tip and the entire portion of the linear body that will become the tip base core metal are heated at approximately 200°C.
Heat-treated for about 24 hours, and then heated the tip of the tip base part and the part that will become the tip part core metal to 400 ml.
Heat treatment at ~500℃ for about 2 hours so that the flexibility of the part that will become the core metal at the tip base gradually increases from the base toward the tip.Finally, the part that will become the core metal at the tip part is formed into a J shape. 5 at about 800℃ while holding
It can be formed by heat treatment for about seconds.

Furthermore, it is preferable that the tip base metal core 22 is more flexible on the tip side, and in particular, it is preferable that the tip base metal core 22 gradually becomes more flexible toward the tip. Therefore, the second
In the example shown in the figure, the diameter gradually becomes smaller toward the tip, and by changing the diameter,
Flexibility can be changed according to adaptation.
Further, the flexibility can also be changed by changing the heat treatment conditions of the alloy forming the tip base core metal 22 as described above.

The length of the tip base core bar 22 is 10 mm to 500 mm.
mm, preferably 30 mm to 300 mm.

The connection between the tip base core bar 22 and the main body core bar 8 is such that the tip base core bar 22 is connected to the tip of the main body core bar 8.
Known methods such as fitting the proximal ends of the two together, brazing the two together, or a combination of both can be used. In particular, as shown in FIG. 2, a hole having a diameter equal to or slightly larger than the diameter of the base end of the tip base core metal 22 is provided at the tip of the main body core metal 8, and the tip base core metal 22 is inserted into the hole.
Insert the proximal end of the
It is preferable that the two be fixed together by 2, and by doing so, the two can be firmly connected.

The coil spring 20 has the functions of preventing the distal end of the guide wire from buckling even in a bent vascular region, uniformizing the outer diameter of the guide wire, and improving X-ray contrast properties. be.

The coil spring 20 has a wire diameter of 0.05~
0.2 mm stainless steel, platinum, platinum alloy, tungsten or palladium/silver alloy, etc. can be suitably used, especially platinum, platinum alloy, tungsten, or palladium alloy, such as palladium/silver alloy, etc., which have excellent X-ray contrast properties. is suitable. By using the above materials, the position of the distal end within the blood vessel can be more easily confirmed during X-ray contrast imaging. The outer diameter of the coil spring 20 is 0.2 to 1.8 mm, preferably 0.25 to 1.6 mm.
It is. The coil spring 20 encloses a tip core metal 21 and a tip base core metal 22,
The inside of the distal end is fixed to the distal end of the distal end core bar 21 with a solder or the like, and the base end is fixed with a wax or the like near the connection between the distal end base core bar 22 and the main body core bar 8.

The tip of the coil spring 20 is a hemispherical tip 9. The hemispherical tip means that the tip is substantially curved, and includes shapes such as a bell shape, a bullet shape, and the like.
Furthermore, the coil spring 20 has only its shape memory portion 2 made of platinum, which has an excellent X-ray contrast effect.
Formed by platinum alloys, tungsten or palladium alloys, such as palladium/silver alloys,
The superelastic part 3 following the shape memory part 2 may be formed of stainless steel, in which case the connection between the two is as follows.
It is preferable to fix the coil spring 20 by providing a solder 11 on the inner surface of the coil spring 20 near the connecting portion. Further, the stress for returning the shape memory alloy forming the tip core bar 21 to its memorized shape needs to be greater than the bending stress of the coil spring 20. Therefore, it is preferable to use a coil spring 20 that does not have a very large bending stress. Further, in the above description, the tip core bar 21 is formed of a shape memory alloy, but the coil spring 20 on the tip side of the part fixed to the core metal (the wax 11 part) may be made of a shape memory alloy. It may be a shape memory portion, or both may be formed of a shape memory alloy, and both may have approximately the same curved shape memorized. Furthermore, in the above description, the tip base core metal 22 is formed of a superelastic alloy to form a superelastic part, but the present invention is not limited to this. The superelastic portion may be made of a superelastic alloy, or both may be made of a superelastic alloy.

Furthermore, it is preferable to coat the outer surface of the main body core bar 8 with a lubricity agent 13 for reducing the frictional resistance with the inner surface of a cylindrical body such as a catheter. Preferably, it is on the order of microns. As the lubricity agent 13,
Those mentioned above can be suitably used.

Next, an embodiment of the catheter guide wire of the present invention shown in FIG. 3 will be described.

Catheter guide wire 1 shown in Fig. 3
is a shape memory part 2, a superelastic part 3 having superelasticity continuous with this shape memory part 2, and this superelastic part 3.
and a continuous main body portion 4. Specifically, a tip core bar 2 forming a shape memory portion 2
1, a tip base core 22 which is formed integrally with the tip core 21 and is made of a superelastic alloy and forms the superelastic part 3, and a main body core 8 connected to the tip base core 22. , tip core bar 21, tip base core bar 2
2. Synthetic resin 30 covering the entire main body core bar 8
It is made up of.

The flexible part of the guide wire formed by the shape memory part 2 and the superelastic part 3 can be inserted into the meandering blood vessel,
It forms a guiding part to allow the guidewire to easily advance into a blood vessel with a reduced diameter. Therefore, it has to have high flexibility, or in other words, a wide elastic area, and its tip has a It is necessary to have a curved part.

Therefore, in this embodiment, the tip core metal 21 in the shape memory section 2 is formed of a shape memory alloy whose martensitic reverse transformation start temperature is 0°C to 40°C, and furthermore, at a temperature higher than the above temperature. It is a shape memory portion formed to transform into a curved shape. The martensitic reverse transformation initiation temperature is preferably 26°C to 36°C.

The tip core bar 21 has an outer diameter of 0.05 mm to 0.3 mm,
The length is between 10mm and 500mm, preferably between 20mm and 300mm.

The tip base core metal 22 that is continuous with the rear end of the tip core metal 21 has superelasticity, and a superelastic alloy is one that has a wide elastic region that does not undergo plastic deformation even under a tensile strain of about 8%. be. Examples of metals used for integrally molding the tip core metal 21 and the tip base core metal 22 include:
Ni-Ti alloy, Cu-Al-Ni alloy, Cu-Zn-
Al-based alloys and the like are suitable.

As described above, the method for forming the core metal in which the tip portion becomes the shape memory portion and the subsequent portion becomes the superelastic portion is to form the tip core metal 21 and the tip base core metal using the alloy as described above. A linear body of the required length is formed as 22, and first, the tip and the entire portion of the linear body that will become the tip base core metal are heated at approximately 200°C.
Heat-treated for about 24 hours, and then heated the tip of the tip base part and the part that will become the tip part core metal to 400 ml.
Heat treatment at ~500℃ for about 2 hours so that the flexibility of the part that will become the core metal at the tip base gradually increases from the base toward the tip.Finally, the part that will become the core metal at the tip part is formed into a J shape. 5 at about 800℃ while holding
It can be formed by heat treatment for about a period of time.

Furthermore, it is preferable that the tip base core metal 22 is more flexible on the tip side, and in particular, it is preferable that it becomes gradually more flexible toward the tip. By doing so, flexibility can be changed according to adaptation. Further, the flexibility can also be changed by changing the heat treatment conditions of the metal forming the tip base core metal 22 as described above.

The tip base core metal 22 has a diameter of 0.1 mm to 1.8 mm.
mm, length is 10mm-500mm, preferably 30mm-300mm
It is.

The main body core bar 8 is connected to the main body 4 of the guide wire 1.
, and is connected to the rear end of the tip base core bar 22. The main body core bar 8 has a diameter of 0.15
~1.8mm, preferably 0.3~1.6mm, length ~30mm
3500mm, preferably 50mm to 3000mm. As the material for forming the main body core bar 8, those mentioned above can be suitably used.

The rear end of the tip base core bar 22 (the connection part with the main body core bar 8) has a gently tapered shape, and the outer diameter of the rear end of the tip base core bar 22 and that of the main body part 8 are the same. The outer diameters of the tips are approximately equal.

The connecting portion 32 between the tip base core bar 22 and the main body core bar 8 can be made by fitting the proximal end of the tip base core bar 22 onto the tip of the main body core bar 8, or by brazing the two together. It is formed by a known method such as the above method, or a combination of both methods.
In particular, as shown in FIG. 3, the rear end of the tip base core metal 22 has a smaller diameter (not limited to a cylindrical shape) than the outer diameter of the tip base core metal 22, and furthermore, the tip thereof is larger than other parts. A large protrusion is provided, and a hole is provided at the tip of the main body core bar 8 into which the protrusion can be inserted.The protrusion of the tip base core bar 22 is inserted into the hole, and the vicinity of the connecting portion between the two is inserted. It is preferable to fix them with wax, and by doing so, the two can be firmly connected.

The tip of the tip core bar 21 has a rounded shape.

The tip core metal 1, the tip base core metal 22, and the main body core metal 8 are all covered with a synthetic resin 30, and the entire outer diameter of the guide wire is approximately uniform. As the synthetic resin, polyethylene, polyvinyl chloride, polyester, polypropylene, polyamide, polyurethane, fluororesin, silicone rubber, and elastomers thereof can be used. Note that it may not be coated with this synthetic resin 30.

Further, a synthetic resin 30 on which the main body core bar 8 is located
It is preferable to coat the outer surface of the lubricity agent 13 with a lubricity agent 13 for reducing the frictional resistance with the inner surface of a cylindrical body such as a catheter, and the thickness thereof is as follows.
Several microns is preferably about several hundred microns. As the lubricity imparting agent 13, those mentioned above can be suitably used.

[Function] Next, the function of the catheter guide wire of the present invention will be explained using the embodiment shown in FIG.

The guide wire 1 of the present invention is used for guiding a catheter such as an angiography catheter or a vasodilator catheter when it is inserted into a target site of a blood vessel.
To insert the catheter, first, a blood vessel is secured in the human body by the Seldinger method or the like, and then the catheter guide wire 1 of the present invention is placed in the blood vessel, and the catheter is inserted into the blood vessel along it. If the tip of the guide wire is curved before insertion, cool the tip with ice water, etc., stretch it into a straight line, and then insert it. In this insertion, the catheter guide wire 1 is inserted into the blood vessel with the catheter guide wire 1 protruding several centimeters (coil spring portion) from the tip of the catheter. The tip of this guide wire restores its curved shape when heated, so it can be easily inserted into a tortuous blood vessel or into a blood vessel with neutral fat, cholesterol, etc. Furthermore, the base that follows the tip has a superelastic part made of a superelastic alloy, so it is sufficiently flexible and can be easily inserted into tortuous blood vessels and narrow blood vessels. can. After the tip of the catheter has been guided to the vicinity of the target site, the guide wire 1 is removed, and if the catheter is an angiography catheter, from the rear end,
An angiographic contrast agent is injected, an X-ray contrast is performed, the catheter is removed, and the procedure is completed by applying pressure to stop the bleeding.

[Effects of the Invention] The catheter guide wire of the present invention is a catheter guide wire having a flexible distal end portion and a main body portion, the distal end portion is a guide wire, and the distal end portion is a guide wire. Provided on the tip side, martensite reverse transformation start temperature is 0℃
A shape-memory part made of a shape-memory alloy whose temperature is between 40°C and 40°C, and formed to transform into a curved shape at a temperature higher than the temperature, and a super-elastic part made of a super-elastic metal following the shape-memory part. In particular, it has a shape memory part that transforms into a curved shape at the tip, so when it is inserted into a blood vessel, it can be inserted in a straight state, unlike the conventional tip. There is no need to use a guide inserter, which is required when inserting a guide wire with a curved section, and it can be easily inserted into a blood vessel. Furthermore, since the superelastic part following the shape memory part has superelasticity, it is sufficiently flexible and can be easily inserted into tortuous blood vessels and narrowed blood vessels, and furthermore, there is a risk of damaging the blood vessel wall. There is no.

Furthermore, as mentioned above, since it has a shape memory part and a superelastic part formed of a superelastic metal following this shape memory part, the shape memory part restores the memorized shape, and the atoms of the superelastic metal The arrangement state becomes austenite phase, the hardness is high, and there is little plastic deformation or elastic deformation, and even if this shape memory part comes into contact with the blood vessel wall during insertion into the blood vessel, the shape of this shape memory part is maintained as it is. In this state, the continuous superelastic part deforms elastically, so it does not press strongly against the blood vessel wall, and even if the curved shape memory part gets caught in the branching part of the blood vessel, the continuous superelastic part deforms elastically. Since the elastic portion elastically deforms, it is possible to escape from that state without damaging the blood vessel wall. Further, as described above, the shape memory portion has high hardness when restored to the memorized shape, and therefore has high shape stability. Therefore, even if the shape memory portion comes into contact with the blood vessel wall, it does not easily deform, so that the purpose of forming the shape into a curved shape can be reliably achieved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of the catheter guide wire of the present invention, FIG. 2 is a sectional view showing another embodiment of the catheter guide wire of the present invention, and FIG. 3 is a sectional view showing another embodiment of the catheter guide wire of the present invention. FIG. 3 is a sectional view showing another embodiment of the catheter guide wire of FIG. DESCRIPTION OF SYMBOLS 1... Catheter guide wire, 2... Shape memory part, 3... Superelastic part, 4... Main body part, 5...
...Tip coil spring, 6...Superelastic core metal,
7... Base coil spring, 8... Main body core metal, 11, 12... Wax, 13... Lubricity imparting agent, 20... Coil spring, 21... Tip part core metal, 22... Tip base core Gold, 30...Synthetic resin.

Claims (1)

[Claims] 1. A catheter guide wire having a flexible tip and a main body, the tip being provided on the distal side of the guide wire and having a martensitic reverse transformation starting temperature of 0°C to 40°C. A shape-memory part made of a shape-memory alloy that is formed to transform into a curved shape at a temperature higher than the above temperature, and a super-elastic part made of a super-elastic metal following the shape-memory part. A catheter guide wire characterized by: 2. The guide wire for a catheter according to claim 1, wherein the guide wire has a core metal and a coil spring that encloses at least a distal end portion of the core metal. 3. The shape memory portion is formed by the tip of the coil spring.
The guide wire for catheters described in section. 4. The guide wire for a catheter according to claim 2, wherein the shape memory portion is formed by a distal end portion of the metal core. 5. The coil spring has a tip coil spring and a base coil spring continuous with the tip coil spring, and the shape memory portion is formed by the tip coil spring. The guide wire for catheters described in section. 6. The catheter guide wire according to claim 5, wherein the superelastic portion is formed by the base coil spring. 7. The core metal has a tip core metal and a tip base core metal that is continuous with the tip core metal, and the shape memory portion is formed by the tip core metal. The catheter guide wire according to item 2. 8. The catheter guide wire according to any one of claims 2 to 7, wherein the tip of the metal core is fixed to the tip of the coil spring. 9. The guide wire for a catheter according to claim 7 or 8, wherein the superelastic portion is formed of the tip base metal core. 10 The tip of the core metal is not fixed to the tip of the coil spring, the core metal is fixed near a continuous portion of the tip coil spring and the base coil spring, and the shape The memory portion is formed by the tip coil spring, and the superelastic portion is formed by the core metal on the rear end side of the fixed portion between the core metal and the coil spring. The guide wire for catheters described in section. 11. Claims 2 to 1, wherein the coil spring covers the entire core metal.
The catheter guide wire according to any one of Item 0. 12. According to any one of claims 2 to 11, the core metal has a main body core metal continuing to a tip portion, and the tip portion has a smaller diameter than the main body core metal. Guidewire for the catheter described. 13 The guide wire includes a tip core metal forming the shape memory portion, a tip base core metal forming a superelastic portion continuous with the tip core metal, and a main body core continuous with the tip base core metal. The guide wire for a catheter according to claim 1, which is made of a metal core having gold. 14. Claim 1, wherein the guide wire has an outer surface coated with synthetic resin.
The catheter guide wire according to item 3. 15 The martensitic reverse transformation start temperature of the shape memory alloy forming the shape memory portion is between 26°C and 36°C.
15. The guide wire for a catheter according to any one of claims 1 to 14, wherein the temperature is .degree. 16. Claim 1, wherein the tip core metal and the tip base core metal have a smaller diameter than the main body core metal.
The catheter guide wire according to item 3.