JPH0712379B2 - Catheter guide wire core and catheter guide wire - Google Patents

Description

TECHNICAL FIELD The present invention relates to a core material of a catheter guide wire which is a medical instrument and a catheter guide wire.

[Prior Art] In general, a catheter guide wire is punctured from a blood vessel portion, and after being introduced into the blood vessel by a Seldinger needle,
It is a medical instrument used to remove the Seldinger needle from the guide wire and guide the catheter to the main vessel, especially the target site in the blood vessel, prior to the catheter.

For this reason, the core material of the catheter guide wire is composed of a distal end portion having a complicated shape and a matrix portion having a linear shape continuous with the distal end portion. In addition, the core material of the catheter guide wire has a reversible shape and reversible absorption and release of energy at the living body temperature (37 ° C) accompanying the loading and removal of deformation stress including twisting that occurs when it is introduced into the blood vessel and moved. It is necessary to have elastic properties capable of deforming and recovering.

As a core material that retains these properties, a coil-shaped stainless steel wire or piano wire or a monofilament-shaped plastic material has been conventionally used.

On the other hand, it is well known that TiNi alloys in the vicinity of the equiatomic ratio exhibit a remarkable shape memory effect and superelasticity in association with the reverse transformation of the thermoelastic martensitic transformation. Alloys exhibiting these properties are TiNi alloys and TiNiX alloys (X = Cu, Cr, Fe, Al, V, Co
…） And Cu-based alloys such as Cu-Zn-Al, AuCd alloys, AgCd alloys, etc. Recently, research on TiPd alloys as high-temperature actuating elements has been conducted, and TiPd alloys and TiPd alloys have been studied.
The TiPdX alloy in which part of the Pd of the alloy was replaced by Fe, Cu, Co, and Ni was 50
Operation at a temperature of about 0 ° C. is disclosed in Japanese Patent Laid-Open No. 46-1502.

A core material utilizing the superelastic function of TiNi alloy has come to be widely used for catheter guide wires (Japanese Patent Laid-Open No. 60-63066).

[Problems to be Solved by the Invention] However, the X-ray contrast property of TiNi alloy is poor, and it is usually the case that the synthetic resin coating of the core material contains a substance having high contrast property such as W, Ba, Bi, Pb. there were. In addition, the guide wire for small blood vessels such as the brain and peripheral parts cannot be thickened with a synthetic resin coating using a thin wire with a diameter of φ0.2 mm to φ0.4 mm as a core material, so a metal such as Au is capped or coated at the introduction tip. It had the drawback of having to do it.

Moreover, while the superelastic wire of TiNi alloy shows good flexibility,
There was a difficulty in lacking a sense of rigidity. For this reason, it may be difficult to guide the guide wire to a desired part in the body against the force such as the contraction of the blood vessel, and there is an unavoidable restriction on the application.

Then, the 1st technical subject of this invention is providing the catheter guide wire core material with which the X-ray contrast property of at least the tip part was hold | maintained in view of the said fault.

A second technical object of the present invention is to provide a catheter guide wire in which the elasticity of the distal end portion / substrate portion is maintained at least at 37 ° C. and at least the substrate portion has rigidity.

[Means for Solving the Problems] According to the present invention, in a core material of a guide wire having a tip portion and a substrate portion integrally formed with each other, at least the tip portion is made of a TiPd-based shape memory alloy. The core material of the catheter guide wire is obtained.

Further, according to the present invention, the TiPd-based shape memory alloy is Pd:
A part of Pd of TiPd alloy consisting of 45 to 51 at% remaining Ti is V, Cr, Mo,
1.0-30 at% in total of at least one of Ni, Fe, Co, Cu
A catheter guide wire core material having a substituted composition and exhibiting an elastic function at least at body temperature (37 ° C) is obtained.

According to the present invention, the TiPd-based shape memory alloy is Pd45.0
The core material of the guide wire is characterized by having a composition in which a part of Pd of the TiPd alloy consisting of ~ 51.0at% residual Ti is replaced by either W or Ta or by the total amount of 1.0-30.0at%. can get.

Further, according to the present invention, a part of Pd of the TiPd (W, Ta) alloy is composed of at least one of V, Cr, Mn, Ni, Fe, Co and Cu.
It has a composition with 1.0 to 30.0 at% substitution and at least body temperature (3
A core material for a catheter guide wire is obtained which has an elastic function at 7 ° C.

In addition, in the alloy according to the present invention, the Pd amount of the basic TiPd alloy is 45.0 to
The reason why 51.0 at% is set is that if it is less than 45 at%, workability and shape memory are difficult, and if it exceeds 51 at%, only the workability is deteriorated. Further, the substitution amount of the third and fourth elements is set to 1.0 to 30.0 at% because the substitution effect is thin when it is less than 1.0 at% and the substitution effect is remarkable when it exceeds 30 at%, but the workability, This is because it tends to deteriorate the elastic properties.

Embodiments Embodiments of the present invention will be described with reference to the drawings.

Part of Pd of Ti-50at% Pd alloy is V, Cr, Mn, Ni, Fe, Co, Cu, W,
And various alloys substituted with 0 to 35 at% of Ta were melted in an argon arc furnace and hot-worked and cold-worked at a temperature of about 1000 ° C to obtain wire rods with a diameter of about 1.0 mmφ.

A part of these wires was cut and subjected to solution treatment at 1000 ℃ × 1.0hr, and the transformation temperature was measured by DSC. FIG. 1 shows the relationship between the addition amount of the third element and the transformation temperature (martensite transformation start temperature = Ms temperature).

Alloys with a maximum of 35% were added to each element, but alloys with Ms temperatures below 0 ° C were excluded from the figure. From the figure, it can be seen that W of the curve 11 and Ta of the curve 12 are less effective in lowering the Ms temperature than other additive elements.

Generally, in order to obtain elasticity near body temperature (37 ° C), the Ms temperature of the solution-treated alloy should be 37 ° C or lower. To obtain an alloy satisfying this purpose, W and Ta
In the case of additional elements other than, one or a combination of two or more can be used arbitrarily, and in the case of W and Ta, it is possible by arbitrarily selecting other elements in addition to one or two of W and Ta. I understood it.

Among the various alloys mentioned above, Ti ₅₀ Pd ₄₀ W ₇ (alloy-1), Ti ₅₀ Pd
₄₃ Ta ₇ (alloy-2), Ti ₅₀ Pd ₃₄ Fe ₁₆ (alloy-3), Ti ₅₀ Pd
₂₄ Ni ₂₄ (alloy-4), Ti ₅₀ Pd ₂₉ W ₇ Fe ₁₄ (alloy-5), Ti ₅₀
Cold working of Pd ₁₉ W ₇ Ni ₂₄ (alloy-6) and comparative alloy Ti ₄₉ Ni ₅₁ (alloy-7) wire rod samples (working rate 10% or more)
Fig. 2 shows the load / unload curves under 3% tension at 37 ℃ at 1000 ℃ × 10min and 400 ℃ × 10min. Alloy-1 and Alloy-2 do not show good elasticity at 1000 ℃ and 400 ℃ treatment because the Ms temperature exceeds 37 ℃. However, Alloy-3, Alloy-4, Alloy-5, and Alloy-6 show good elasticity because the Ms temperature is 37 ° C or less. On the other hand, after cold working, all alloys show good elasticity.

The elastic properties of TiPd-based alloys are inferior to the comparative alloy Ti ₄₉ Ni ₅₁ alloy and are slightly different from the superelasticity which shows a clear yield, but the elongation limit value which shows elasticity compared with conventional spring materials such as piano wires. Is big. Further, since Alloy-1 and Alloy-2 show relatively good elasticity after cold working, it was found that they can be sufficiently applied as the core material of the catheter guide wire which is the object of the present invention.

Next, when looking at the rigidity as a spring material, it can be seen that each of the alloys according to the present invention exhibits a stress value that is about 1.5 times or more that of the comparative alloy.

Regarding the X-ray contrast property, in general, the atomic weight (A) of the element
Increase in proportion to the size of. Therefore, heavy metals such as Ba, W, Ta and Pd or noble metals such as Au and Pt are selected as the contrast effect element. Among the alloys of the present invention, an alloy containing W and Ta, particularly an alloy containing one or two kinds of W and Ta and having an amount of 5 at% or more, has a contrast property of 1.5 times or more that of the TiNi alloy.

The composition of the alloy according to the present invention can be arbitrarily selected depending on whether the purpose is to improve the contrast property, increase the spring composition, or both. That is, the combination can be determined by the Ms temperature effect of each element shown in FIG. 1 and the contrast effect of the added amounts of W and Ta.

Next, an example of the guide wire will be described.

As shown in FIG. 3, the synthetic resin film 4 has a substantially uniform outer diameter including the tip. In particular, the synthetic resin coating 4 has a substantially uniform outer diameter. Synthetic resin coating 4
As the material, polyethylene, polyvinyl chloride, polyester, polypropylene, polyamide, polyurethane, polystyrene, fluororesin, Shinkon rubber or elastomers and composite materials, respectively, are preferably used. It is preferable that the synthetic resin coating 4 is so flexible that it does not hinder the bending of the inner core 2 and that the outer surface is a smooth surface without irregularities. Further, the synthetic resin film 4 is coated with an anticoagulant such as heparon or urokinase, or a silicone rubber, a block copolymer of urethane and silicone (registered commercial method Abucosan), an antithrombogenic material such as hydroxyethyl methacrylate-styrene copolymer. You may. Further, even if the synthetic resin coating 4 is formed of a resin having a low friction surface such as a fluororesin and the outer surface of the synthetic resin coating 4 is coated with a lubricating liquid such as silicone oil, the frictional property of the guide wire 1 is reduced. Good.
Further, in the synthetic resin forming the synthetic resin coating 4, Ba, W,
Fine powder X made of simple metals or compounds such as Bi and Pb
It is preferable to mix a line-contrast substance, which makes it easier to confirm the entire position of the guide wire 1 being introduced into the blood vessel. The synthetic resin film 4 has a substantially uniform outer diameter as described above. The term “substantially uniform” is not limited to being completely uniform, and the tip may have a small diameter. As described above, by making the distal end portion substantially uniform, it is possible to reduce the damage that the distal end of the guide wire may give to the inner wall of the blood vessel.

The outer diameter of the synthetic resin coating is 0.25 to 1.04 mm, preferably 0.30 to
0.64 mm, the thickness of the core material 2 on the main body 2a is 0.03 to 0.30 mm,
It is preferably 0.05 to 0.20 mm.

Further, it is preferable that the synthetic resin film 4 is adhered to the inner core 2 in a close contact state with the synthetic resin, and is also fixed to the front end portion and the base end portion of the inner core 2. Alternatively, the synthetic resin coating 4 may be formed of a hollow tube, and may be fixed to the inner core 2 by adhesion or melt molding at the front end portion and the base end portion of the inner core 2 or at an appropriate portion of the inner core. The tip of the guide wire 1 (the tip of the synthetic resin coating 4) has a hemispherical curved surface as shown in FIG. 3 in order to prevent damage to the blood vessel wall and improve the operability of the guide wire 1. Preferably.

Further, it is preferable that a lubricating substance is fixed on the surface of the synthetic resin film 4. Lubricating substances are substances that have lubricity during lubrication. Specifically, there are water-soluble polymer substances or their derivatives.

That is, as the core material 2 of the guide wire of the present embodiment, the total length is 1800 nm, the tip diameter is 0.06 mm, and the rear diameter is 0.25 mm.
A tape having a diameter of 120 mm tapered from the tip toward the tip was prepared.

Further, the outer surface of the whole core material was coated with polyurethane containing 45% by weight of tungsten fine powder (particle size: about 3 to 4 μm) so that the whole outer diameter was substantially uniform, to form a synthetic resin film. Then, a solution prepared by dissolving maleic anhydride ethyl ester copolymer in tetrahydrofuran so as to be 5.0% by weight was applied to the surface of the synthetic resin coating formed by the above polyurethane, and maleic anhydride ethyl ester copolymer was obtained. It was fixed and a lubricious surface was formed.

The guide wire has an overall length of about 1800 mm and an overall diameter of 0.36 mm.

[Effects of the Invention] As can be seen from the above description, according to the present invention, W, Ta, V,
Catheter guide wire that exhibits high contrast and / or high spring rigidity by using a TiPd-based alloy containing one or more elements of Cr, Mn, Ni, Fe, Co, Cu The core material can be provided.

In addition, among the alloys according to the present invention, Ti-Pd-Fe, Ti-Pd-W
Since alloys with a combination of Fe and the like have excellent compatibility with the subject, they can be sufficiently used in applications where there is a high possibility that they will come into direct contact with the human body, such as long-term storage.

[Brief description of drawings]

Figure 1 shows Ti ₅₀ Pd _50-X X _X (X = W, Ti, V, Cr, Mn, Ni, Fe, Co, C
The relationship between the Ms temperature and the addition amount of the alloy added in the form of u) is shown. Figure 2 shows Ti ₅₀ Pd ₄₃ W ₇ (alloy-1), Ti ₅₀ Pd ₄₃ Ta ₇ (alloy-2), Ti ₅₀ Pd ₃₄ Fe ₁₆ (alloy-3), Ti ₅₀ Pd ₂₄ Ni ₂₆ (alloy-). 4), Ti ₅₀ Pd ₂₉ W ₇ Fe ₁₄ (alloy-5), Ti ₅₀ Pd ₁₉ W ₇ Ni
_The wire rods of ₂₄ (alloy-6) and Ti ₄₉ Ni51 (alloy-7) were cold-worked, and were loaded and removed under 3% tension at 37 ° C after 1000 ° C x 10min treatment and 400 ° C x 10min treatment. The load curve is shown. FIG. 3 is a side view of a catheter guide wire coated with a synthetic resin according to the present invention. In the figure, 1 ... Guide wire, 2 ... Inner core, 2a ... Inner core body, 4 ... Synthetic resin.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kugo ▲ High ▼ Hiroshi 150, Mainogicho, Fujinomiya-shi, Shizuoka Terumo Co., Ltd. (72) Inventor Yasuo Miyano, 150 Maibokicho, Fujinomiya-shi, Shizuoka Terumo Co., Ltd.

Claims (5)

[Claims] 1. A core material of a catheter guide wire having a tip portion and a substrate portion which are integrally formed with each other, wherein at least the tip portion is made of a TiPd-based shape memory alloy. Core material. 2. The catheter guide wire core material according to claim 1, wherein the TiPd-based alloy is Pd: 45.0 to 51.0 at.
%, A part of Pd of TiPd alloy consisting of residual Ti is V, Cr, Mn, Ni, Fe,
A core material for a catheter guide wire, which has a composition in which at least one of Co and Cu is substituted in a total amount of 1.0 to 30.0 at% and has an elastic function at least at body temperature (37 ° C). 3. The catheter guide wire core material according to claim 1, wherein the front TiPd-based alloy is Pd: 45.0 to 51.0 at.
%, A part of Pd of a TiPd alloy consisting of residual Ti is replaced by at least one of W and Ta in a total amount of 1.0 to 30.0 at%, and a core material for a catheter guide wire, characterized in that: 4. The core material for a catheter guide wire according to claim 3, wherein a part of Pd of the TiPd alloy is V, Cr, M.
1.0 to 30.0 in total of at least one of n, Ni, Fe, Co, Cu
It has a composition with at% substitution, and at least body temperature (37
A core material for a catheter guide wire, which has an elastic function at (° C). 5. A catheter guide wire, characterized in that the core material of the catheter guide wire according to any one of claims (1) to (4) is covered with a synthetic resin.