JPH01135363A - Guide wire for catheter - Google Patents

Abstract

PURPOSE:To improve softness and restoring force of a guide wire for a catheter by making its soft body of a tip and a base the tip including a part composed of a shape-memory alloy and the base including a part composed of a super- resilient metal. CONSTITUTION:A guide wire 1 for a catheter includes a soft body and a main body 4 connected to the soft body. The soft body is made of a tip 2, which includes a coil spring 5 composed of a shape-memory alloy on a free end, and a base 3, which is connected to the tip 2 and includes a super-resilient core metal 6 composed of a super-resilient alloy. The main body 4 includes a core metal 8. A coil spring 7 of the base 3 is fixed near the connection between the super-resilient core metal 6 and the core metal 8 of the main body on one end and is connected to the rear end of the coil spring 5 on the other end.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a catheter guide wire for introducing a catheter for treatment or examination into a target site in a body cavity such as a blood vessel, gastrointestinal tract, or trachea. Regarding.

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

After a guide wire is inserted into a blood vessel along with a catheter, it is used to guide the catheter to the target blood vessel site.
The tip of the guide wire is made to protrude a predetermined length from the tip of the catheter, and the tip of the guide wire is pushed ahead of the catheter.

Therefore, the tip of the guide wire is required to be flexible so that it can 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 present applicant has proposed a guide wire that solves the above problems (Japanese Patent Application Laid-Open Nos. 60-63065 and 60-63066).

The above-mentioned guide wire has sufficient flexibility and restorability, but a straight guide wire can be used satisfactorily for patients with a small amount of tortuous aorta, generally young patients, but in elderly patients, where the aorta has a large amount of meandering. In patients who have a large amount of cholesterol, etc. deposited in their arterial blood vessels, it may be difficult to insert a guide wire with a straight tip as described above, so a guide wire with a curved tip is used. was.

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.

[Problems to be solved by the invention] The above-mentioned JP-A-60-63065, JP-A-60-6
The guidewire disclosed in Publication No. 3066 has sufficient flexibility and resilience, but the guidewire with a curved tip cannot be inserted into the Seldinger needle that is punctured to insert the catheter into the femoral artery. The problem was that it was difficult.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a catheter guide wire that has high flexibility and resilience and can be easily inserted into a Seldinger needle even if the guide wire has a curved tip. .

[Means for solving the problem] A device that achieves the above purpose has a flexible portion in the distal direction,
In the guide wire for a catheter having a main body portion in the proximal direction, the flexible portion is made of a shape memory alloy whose martensitic reverse transformation initiation temperature is 0° C. to 40° C., and is curved at a temperature higher than the above temperature. The present invention is a guide wire for a catheter that includes a distal end portion having a shape memory portion formed to transform, and a base portion having a superelastic portion formed of a superelastic metal following the distal end portion.

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.

Further, the shape memory portion is formed, for example, by the tip portion 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. It is. Furthermore, the superelastic portion is formed by, for example, the base coil spring. Furthermore, the core metal has, for example, a tip core metal and a base core metal that is 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 of, for example, the 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, the core metal has a main body core metal that continues to the tip portion, and the tip portion includes:
It is preferable that the main body portion has a smaller diameter than the core metal. moreover,
The guide wire includes, for example, a tip core metal forming the shape memory portion, a base core metal forming a superelastic portion continuous with the tip core metal, and a main body core metal continuous with the base core metal. It consists of a core metal having. Furthermore, it is preferable that the outer surface of the guide wire is coated with a synthetic resin. Furthermore, the martensitic reverse transformation start temperature of the shape memory alloy forming the shape memory portion is
Preferably the temperature is 26°C to 36°C. Further, it is preferable that the tip core metal and the base core metal have smaller diameters 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 l of the present invention is a catheter guide wire having a flexible portion in the distal direction and a main body portion 4 in the proximal direction, and the flexible portion has a martensitic reverse transformation starting temperature of 0° C. to 40° C. The distal end portion 2 is made of a shape memory alloy having a temperature of 0.degree.
and a base part 3 having a superelastic part made of superelastic metal following the tip part 2.

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

A catheter guide wire 1 shown in FIG. 1 has a flexible portion formed by a distal end portion 2 having a shape memory portion provided in the distal direction, and a base portion 3 having a superelastic portion continuous with the distal end portion 2. and a main body part 4 that is continuous with the base part 3. To be more specific, the tip coil spring 5 is made of a shape memory alloy and forms a shape memory part, and the rear end of the tip coil spring 5 is made of a shape memory alloy. A superelastic cored metal 6 that is made of a fixed superelastic alloy and forms a superelastic part, a main body cored metal 8 connected to the rear end of the superelastic cored metal 6, and a base end that is connected to the superelastic cored metal 6. It consists of a base coil spring 7 which is fixed near the connection part with the main body core metal 8 and whose tip is continuous with the rear end of the tip coil spring 5.

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 not fixed to the tip of the tip coil spring 5, and the tip of the guide wire 1 is formed only by the tip coil spring 5.

The main body core bar 8 forms the main body 4 of the guide wire 1, and preferably has a function of reliably transmitting an operation at the proximal end (hand at the time of use) of the main body 4 to the distal end. , Therefore, it is preferable to be formed of a material with high rigidity. As for rigidity, bending rigidity is 15 to 9.
It is preferably xx" or more, preferably 18 to 9xm" 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, , and the proximal end (hand) of the guide wire when rotating it.
The force from the operation can be reliably transmitted to the tip, making insertion easier.

The main body core bar 8 has a diameter of 061 to 1.8 cm.
, preferably 0.15-1.6mm, length 30xm
~3500jlj1. Preferably it is 50 mm to 3000 liters.

The flexible portion of the guide wire formed by the tip portion 2 and the base portion 3 forms a guiding portion for advancing the guide wire through meandering blood vessels and narrow blood vessels, and therefore has high flexibility. In other words, it is necessary to have a wide elastic region and a curved portion at the tip.

Therefore, in this embodiment, the tip coil spring 5 forming the tip 2 is made of a shape memory alloy whose martensitic reverse transformation start temperature is 0°C to 40°C, and is further heated to a temperature higher than the above temperature. The shape memory portion is formed so as to transform into a curved shape. As shape memory alloys, I'ji-Ti alloys,
Au-Cd based alloy, Cu -A I -N based alloy,
It is formed from Cu-Au-Zn alloy, Ni-Al alloy, etc., and furthermore, the martensite reverse transformation start temperature of the shape memory alloy (the temperature at which the martensite phase begins to disappear and becomes the parent phase, austenite phase) is A temperature range of 0°C to 40°C is used. Further, the tip coil spring 5 is formed into a curved shape, for example, a J shape, at a high temperature, and remembers the 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 becomes the memorized curved shape. Restore to.

Shape memory alloys with a martensite reverse transformation initiation temperature of 40°C or lower are used because blood cell components and tissue cells are likely to be destroyed at approximately 42°C, so they cannot be introduced into blood vessels. It is preferable that the limit for heating the distal end of the guide wire (e.g., high frequency heating, heat transfer by heating the rear end of the guide wire) is up to 42°C, and the distal end coil spring 5 has a curved shape. The return of
If the martensite reverse transformation start temperature is 40°C, it is possible at 42°C, which is 2°C higher than that temperature. That is, if the martensite reverse transformation start temperature is 40°C or lower, 42
Since it almost returns to its memorized curved shape when heated to 40°C, the temperature was set at 40°C, which is 2°C lower than the possible temperature of 42°C.

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 martensite reverse transformation start temperature is 0° C. to 25° 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) should be immersed in ice water or alcohol cooled with ice water to cool it and straighten the tip before use immediately. . The martensite reverse transformation starting temperature is preferably 26°C to 36°C, and if it is 26°C or higher, there is little possibility that it will return to the curved shape due to the room temperature in the operating room as described above. There is no need to cool or straighten the
If it is below 6 degrees Celsius, the temperature of the blood is about 38 degrees Celsius, so by inserting it into the blood vessel, it will be warmed by the blood and return to its naturally memorized curved shape, so other means can be used. There is no need for external heating.

The length of the tip coil spring 5 is l10l1.
~500RJ11 preferably 201m~300m+11
It is.

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 wide elastic range that does not undergo plastic deformation even under a tensile strain of about 8%. For example, Ni
-Ti alloy, Cu-Al-Ni alloy, Cu-Zn-
Superelastic metals such as Al-based alloys are preferred.

The tip of the tip coil spring 5 is 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 bar 6 is more flexible on the tip side, and in particular, it is preferable that the superelastic cored bar 6 becomes more flexible gradually 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. In addition, the change in flexibility is due to the superelastic core metal 6
This can also be achieved by changing the heat treatment conditions of the alloy forming the .

As the superelastic core metal 6, the length is 5Qxx -11000
0R.

Preferably it is 100zz to 81103!31.

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.

The base coil spring 7 has a wire diameter of 0.05 to 0.
211 stainless steel, platinum, platinum alloys, tungsten or palladium/silver alloys, etc., and in particular, platinum, platinum alloys, tungsten, or palladium alloys, such as palladium/silver alloys, which have excellent X-ray contrast properties. suitable. By using the above materials,
During X-ray imaging, the position of the tip within the vessel can be more easily confirmed. The outer diameter of the base coil spring 5 is 0.2 to 1.8 mm, preferably 0.25 mm.
~1.6xx. And the base coil spring 7
covers the 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, etc., and the base end is wrapped around the superelastic cored metal 6. 6 and the zero body core metal 8 are fixed with wax 12 or the like near the connection part.

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. Insert the proximal end of the superelastic core bar 6 having a groove, and apply the wax 1 near the connecting part between the two.
It is preferable that the two be fixed together by 2, and by doing so, the two can be firmly connected.

In the above description, the superelastic part is formed of the superelastic cored metal 6, but the invention is not limited to this, and the cored metal 6 may be formed without using a superelastic metal, and the base coil spring 7 can be formed of a superelastic metal. , may be used as a superelastic part, and furthermore, the core bar 6
Both the base coil spring 7 and the base coil spring 7 may be formed of superelastic metal.

Further, a lubricity agent 13 is provided on the outer surface of the main body core bar 8 to reduce frictional resistance with the inner surface of a cylindrical body such as a catheter.
The thickness of the coating is preferably from several microns to several hundred 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 polymer substances (e.g., methyl vinyl ether maleic anhydride copolymer), acrylamide-based polymer substances (e.g., polyacrylamide), polyethylene oxide-based polymer substances (e.g., polyethylene oxide, polyethylene glycol), polyvinyl alcohol ,
Polyacrylic acid-based polymer substances (e.g., sodium polyacrylate), phthalic acid-based polymer substances (e.g., polyhydroxyethyl phthalate), water-soluble polyester (
For example, polydimethylolpropionic acid ester), ketone aldehyde resin (eg, methyl isopropyl ketone formaldehyde), polyvinylpyrrolidone, polyethyleneimine, polystyrene sulfonate, water-soluble nylon, and the like 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 the water-soluble polymeric substance or its derivative, the above-mentioned substances can be suitably used.

Reactive functional groups include isocyanate groups, amino groups,
Aldehyde groups, epoxy groups, etc. are suitable; therefore,
Suitable examples of the compound having a reactive functional group and coating-forming properties include polyurethane and polyamide.

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, and diphenylmethane diisocyanate, and adducts or prepolymers of these isocyanates and polyols, polyamines (e.g., low molecular weight polyamines,
Examples include ethylene diamine, trimethylene diamine, and polymeric polyamine (geltaldehyde). In addition, as a coating method, a material having a reactive functional group (for example, a solution of polyurethane (tetrahydrofuran solution)) and a substance having a reactive functional group [for example, 4.4
The coated area (outer surface of the first linear body 2) is brought into contact with a mixture of a solution of diphenylmethane diisonanate (methyl ethyl ketone solution), and after drying, a water-soluble polymer [e.g., methyl vinyl ether Contact with a solution of maleic anhydride copolymer (methyl ethyl ketone solution),
This can be done by 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.

The catheter guide wire 1 shown in FIG. 2 includes a distal end portion 2 having a shape memory portion, a base portion 3 having a superelastic portion continuous with the distal end portion 2, and a main body portion 4 continuous with the base portion 3.
Specifically speaking, a tip core metal 21 forms a shape memory portion, and a base core metal 22 forms a superelastic portion continuous with the rear end of the tip core metal 21. and a main body cored metal 8 connected to the rear end of the base cored metal 22; It consists of a coil spring 2G fixed to the tip.

The main body core bar 8 forms the main body 4 of the guide wire l, and preferably has a function of reliably transmitting an operation at the proximal end (hand at the time of use) of the main body 4 to the distal end. , Therefore, it is preferable to be formed of a material with high rigidity. As for rigidity, bending rigidity is 15kg.
xx" or more, preferably IBkgxm" is preferred. Stainless steel or the like is suitable as the material for the main body core bar 8, and high tensile stainless steel for springs is particularly suitable.

The main body core bar 8 has a diameter of 0.1 to 1.8x.
x, preferably 0.15-1.6zi, length 30xm
-3500 xm, preferably 50321-3000 xm.

The flexible part of the guide wire formed by the tip part 2 and the base part 3 forms a guiding part for advancing the guide wire through a meandering blood vessel or a narrow blood vessel, and therefore has high flexibility. In other words, it is necessary to have a wide elastic region and a curved portion at the tip.

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

The length of the tip core bar 21 is LOmrtt~101
0Ox is preferably 15th order M to 10mm.

Then, a base core bar 22 that is continuous with the rear end of the tip core bar 21
is made of a superelastic alloy, and the 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%.

In this embodiment, the tip core bar 21 forming the shape memory section and the base core bar 22 forming the superelastic section are integrally molded.

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

As described above, in order to make the tip become a shape memory part and the following base part a superelastic part, the tip core bar 21 and the base core bar 22 are made of the above-mentioned alloy with the required length. A linear body is formed, and first the tip of this linear body “
The entire part that will become the base mandrel and the base mandrel are heat-treated at about 200°C for about 24 hours, and then the tip of the part that will become the base mandrel and the part that will become the tip mandrel are heat-treated at 400 to 500°C for about 2 hours. Then, the flexibility of the part that will become the base core bar gradually increases from the base toward the tip.Finally, the part that will become the tip core bar is formed into a J-shape, and while holding it, it is molded for about 8 (1
It can be formed by heat treatment at 0° C. for about 5 seconds.

Further, it is preferable that the base core metal 22 is more flexible at the tip side, and in particular, it is preferable that the tip gradually becomes softer toward the tip. Therefore, in the embodiment shown in FIG. 2, the diameter gradually decreases toward the tip. By changing its 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 base core metal 22 as described above.

The length of the base core metal 22 is LOxm to 500xi,
Preferably it is 3011-300xm.

The base core bar 22 and the main body core bar 8 can be connected by a known method such as fitting the proximal end of the base core bar 22 onto the tip of the main body core bar 8 or brazing the two together. or a combination of both methods can be used. In particular, as shown in FIG. 2, a hole having an inner diameter equal to or slightly larger than the diameter of the base end of the base core metal 22 is provided at the tip of the main body core metal 8, and the base of the base core metal 22 is inserted into the hole. It is preferable to insert the end portion and fix the vicinity of the connecting portion between the two with the solder 12. 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. .

The coil spring 20 has a wire diameter of 0.05 to 0.2.
No. 11 stainless steel, platinum, platinum alloy, tungsten or palladium/silver alloy, etc. can be suitably used, and in particular,
Platinum, platinum alloys, tungsten, or palladium alloys, such as palladium/silver alloys, which have excellent X-ray contrast effects, are 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 L;
8zm, preferably 0.25 to 1.6zl. The coil spring 20 encloses the tip core metal 21 and the base core metal 22, and the inside of the tip covers the tip core metal 21 and the base core metal 22.
The distal end thereof is fixed with a solder or the like, and the base end is fixed with a wax or the like near the connecting portion between the base cored metal 22 and the main body cored metal 8.

The tip of the coil spring 20 is a hemispherical tip 9. A hemispherical tip means a substantially curved tip, and includes shapes such as a bell shape and a bullet shape. Furthermore, coil spring 2
0, only the tip 2 is made of platinum, platinum alloy, tungsten, or palladium alloy, such as palladium/silver alloy, which has an excellent X-ray contrast effect, and the base 3 following the tip 2 is made of stainless steel. In that case, the connection between the two is preferably fixed 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. moreover,
In the above description, the base core metal 22 is formed of a superelastic alloy to form a superelastic part, but this is not limited to the part that is fixed to the core metal (
The coil spring 20 on the rear end side of the row 11 (portion 11) may be made of a superelastic alloy to serve as a superelastic part, or both may be made of a superelastic alloy.

Further, a lubricity agent 13 is provided on the outer surface of the main body core bar 8 to reduce frictional resistance with the inner surface of a cylindrical body such as a catheter.
The thickness of the coating is preferably from several microns to several hundred microns. As the lubricity imparting 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.

The guide wire l for catheter shown in FIG.
Specifically, it consists of a tip core metal 21 that forms a shape memory portion, and a base portion that is formed integrally with the tip core metal 21 and is made of a superelastic alloy and forms a superelastic portion. Core bar 22 and main body core bar 8 connected to base core bar 22
and a proximal core bar 21. It consists of a base core metal 22 and a synthetic resin 30 that covers the entire body core metal 8.

Tip 2 and base 3. The flexible part of the guide wire formed by this forms a guiding part for advancing the guide wire through a meandering blood vessel or a narrow blood vessel, and therefore has high flexibility, in other words. It is necessary to have a wide elastic region and a curved portion at the tip.

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

The tip core bar 21 has an outer diameter of 0.05xm to 0.3mm and a shoulder 11 length of LOxm to 500xm, preferably 20x*
~30011.

Then, a base core bar 22 that is continuous with the rear end of the tip core bar 21
has superelasticity, and a superelastic alloy is one that has a wide elastic range that does not undergo plastic deformation even under a tensile strain of about 8%. Then, the tip core bar 21 and the base core bar 22
As the metal used for integrally molding, for example, Ni-Ti alloy, Cu-AI-Nf alloy, Cu-Zn-Al alloy, etc. are suitable.

As described above, in order to make the tip become a shape memory part and the following base part a superelastic part, the tip core bar 21 and the base core bar 22 are made of the above-mentioned alloy with the required length. First, the tip of this linear body and the entire portion that will become the base core metal are heat-treated at approximately 20Q°C for about 24 hours, and then the tip of the portion that will become the base core metal and the tip core are heated. The part that will become the gold is heat treated at 400-500℃ for about 2 hours so that the flexibility of the part that will become the base metal core gradually increases from the base toward the tip, and finally the part that will become the tip metal core is heated. Form into a J shape and hold at approximately 800℃
It can be formed by heat treatment for about 5 seconds.

Furthermore, it is preferable that the base core metal 22 is more flexible on the tip side, and in particular, it is preferable that the tip becomes gradually more flexible toward the tip, and the diameter may be gradually reduced toward the tip.
By changing its diameter, the flexibility can be changed depending on the application. Further, the flexibility can also be changed by changing the heat treatment conditions of the metal forming the base core metal 22 as described above.

The base core metal 22 has a diameter of 0.111x to 1.811x.
1! , length is 1011 shoulder to 5GG11. Preferably 30
It is 11-3001m.

The main body core bar 8 forms the main body part 4 of the guide wire 1 and is connected to the rear end of the base core bar 22 . The main body core bar 8 has a diameter of 0.15 to 1.8zz, preferably 0.3 to 1,611mm, and a length of 3011 to 35QOr.
z, preferably 50 m1 to 3000 JEJI. As the material for forming the main body core bar 8, those mentioned above can be suitably used.

The base core metal 22 has a gently tapered rear end (the connection part with the main body core metal 8).
The outer diameter of the rear end of the base core metal 22 and the outer diameter of the tip of the main body portion 8 are approximately equal.

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

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

Then, the base end core metal 21, the base core metal 22, the main body core metal 8
The entire guide wire is covered with a synthetic resin 30, and the entire outer diameter of the guide wire is almost uniform. Synthetic resins include polyethylene, polyvinyl chloride,
Polyester, polypropylene, polyamide, polyurethane, fluororesin, silicone rubber, and elastomers thereof can be used. In addition, this synthetic resin 3
It may not have a zero coating.

Furthermore, it is preferable to coat the outer surface of the synthetic resin 30 on which the main body core bar 8 is located 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 l of the present invention includes an angiography catheter,
It is used to guide a catheter such as a vasodilator catheter when inserting it into the target part of a blood vessel.When inserting a guide wire, first secure a blood vessel in the human body using the Seldingo method, etc. The catheter guide wire I of the present invention is placed in a blood vessel, and the catheter is inserted into the blood vessel along it.

If the tip of the guidewire is curved before insertion, cool it with ice water, etc.
After stretching it into a straight line, insert it. During this insertion, the catheter guide wire 1 is inserted from the tip of the catheter.
Insert into the blood vessel with the tube protruding several cm (coil spring portion). The tip of this guidewire 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. attached. Furthermore, the base part that follows the tip part 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 be done. After the tip of the catheter has been guided to the vicinity of the target site, the guide wire 1 is removed.
If the catheter is an angiography catheter, an angiography medium is injected from its rear end, X-ray contrast is performed, the catheter is removed, and the procedure is completed by applying pressure to stop bleeding.

[Effects of the Invention] The catheter guide wire of the present invention has a flexible portion in the distal direction and a main body portion in the proximal direction, and the flexible portion has a temperature at which martensitic reverse transformation starts. a tip portion made of a shape memory alloy at a temperature of 0° C. to 40° C. and having a shape memory portion formed to transform into a curved shape at a temperature higher than the temperature;
and a base having a superelastic part formed of a superelastic metal following the tip; in particular, since the tip has a shape memory part that transforms into a curved shape,
When inserted into a blood vessel, it can be inserted in a straight state, and there is no need to use a guide inserter, which is required when inserting a conventional guide wire with a curved tip. can be inserted into. Furthermore, since the base part following the tip part has a superelastic part, it is sufficiently flexible and can be easily inserted into tortuous blood vessels and narrow blood vessels, and there is no risk of damaging the blood vessel wall. .

[Brief explanation of the drawing]

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. l...Catheter guide wire 2...Tip part, 3...Base part, 4...Main body part, 5...Tip part coil spring,
6... Super elastic core metal, 7... Base coil spring, 8... Main body core metal, 11.12... Row, 13
...Lubricating agent, 20...Coil spring, 2
1... Tip core metal, 22... Base core metal, 30...
・Synthetic resin,

Claims (16)

[Claims] (1) In a catheter guide wire having a flexible portion in the distal direction and a main body portion in the proximal direction, the flexible portion is made of a shape memory alloy whose martensitic reverse transformation initiation temperature is 0°C to 40°C. , and a tip portion having a shape memory portion formed to transform into a curved shape at a temperature higher than the above temperature, and a base portion having a superelastic portion formed of a superelastic metal following the tip portion. A catheter guide wire featuring: (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 catheter guide wire according to claim 2, wherein the shape memory portion is formed by the distal end portion of the coil spring. (4) The catheter guide wire according to claim 2, wherein the shape memory portion is formed by the 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. Second
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 base core metal 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 catheter guide wire according to claim 7 or 8, wherein the superelastic portion is formed of the base metal core. (10) The tip of the core metal is not fixed to the tip of the coil spring, and the core metal is fixed near a continuous portion of the tip coil spring and the base coil spring, The shape memory portion is formed by the tip coil spring, and the superelastic portion is
The guide wire for a catheter according to claim 5, wherein the guide wire for a catheter is formed by a core metal located at a rear end side of a fixed portion between the core metal and the coil spring. (11) The catheter guide wire according to any one of claims 2 to 10, wherein the coil spring covers the entire core metal. (12) 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 catheters described in the book. (13) The guide wire includes a tip core bar forming the shape memory section, a base core bar forming a superelastic section continuous with the tip core bar, and a main body core bar continuous with the base core bar. Claim 1 consists of a core metal having gold.
The guide wire for catheters described in section. (14) The catheter guide wire according to claim 13, wherein the guide wire has an outer surface coated with a synthetic resin. (15) The catheter guide wire according to any one of claims 1 to 14, wherein the shape memory alloy forming the shape memory portion has a martensitic reverse transformation start temperature of 26°C to 36°C. . (16) The catheter guide wire according to claim 13, wherein the tip core metal and the base core metal have smaller diameters than the main body core metal.