JP3122893B2 - Catheter guidewire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catheter guidewire which is one of medical instruments.

[0002]

2. Description of the Related Art Generally, a catheter guide wire is introduced into a blood vessel by a Seldinger needle punctured from a vascular site, and then the Seldinger needle is removed from the guide wire, and a catheter is attached to the rear end of the guide wire to attach a catheter guide wire. In particular, it is one of the medical instruments used for guiding a catheter prior to the catheter to a target site in a blood vessel.

As is well known, a blood vessel path is a complicated path, or a plurality of blood vessels are cross-connected. For this reason, the core material of the catheter guide wire is composed of a distal end having a complicated shape and a substrate having a linear shape. In addition, the biological temperature (about 37
° C), including torsion that occurs during introduction and advancement into blood vessels.
Since that has elastic properties sufficient deformation and recovery of the absorption and release and reversible shape accompanying energy unloading undeformed stress is required, generally SUS30
4. Heli-carbane made of SUS316 or the like as a spring material, and more recently a Ti-Ni-based shape memory alloy wire is used.

[0004]

However, a catheter guide wire using a Ti-Ni-based alloy material having a mere elastic property as a core material as described above as a core material usually has an elastic property at least at a temperature in a living body. I have.
Therefore, there is a problem of restoring the deformation in the blood vessel, transmitting the torque from the introduction part necessary for changing the direction of the guide wire tip part accompanying the introduction into the blood vessel, and joining the helical coil at the tip part and the wire of the substrate part. was there.

Furthermore, since the length of the portion requiring flexibility at the distal end is fixed, it is often impossible to cope with the complexity of branching of the inserted blood vessel.

[0006]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned drawbacks of the prior art, and has the flexibility of the distal end portion while maintaining the rigidity of the base portion of the catheter guide wire. It is an object of the present invention to provide a catheter guidewire capable of performing the above-described operations.

In order to achieve the above object, the present invention is to dispose a helical coil-shaped or net-shaped Ti-Ni-based shape memory alloy whose tip portion exhibits superelasticity at the temperature in a living body outside a core wire. is there.

[0008]

EXAMPLE A thickness of 50 made of a Ti-51 at% Ni alloy
A ribbon wire having a width of 1.00 mm and a width of 1.00 mm was formed into a helical coil having an outer diameter of 0.5 mm, and subjected to superelastic treatment at 500 ° C. for 5 minutes. As shown in FIG. 1 (A), a stainless wire having a wire diameter of 0.35φ and a Ti-Ni-based superelastic wire 3 were inserted and fixed in the tube 1 thus formed. The core wire was not inserted into the tip 50 mm.

FIG. 1 (B) shows a tube 1 formed in a net shape.
A stainless steel wire or Ti
This shows a state where the Ni-based superelastic wire 3 is inserted and fixed.

Next, the results of these experiments will be described.
The entire length (about 2 m) was covered with a synthetic resin (polyurethane in this example). After the coating was completed, an operability test of the guide wire was performed using a meandering transparent tube 10 as shown in FIG. That is, operability up to the tube inlet,
Operability from the inlet to the tip and the tube 10
Insertion at 37 ° C. was carried out. Table 1 shows the results.

[0011]

[Table 1]

The test was conducted for comparison with a Ti—Ni alloy core material, S
Investigation was conducted on the uS alloy core material. In the case of the Ti—Ni alloy core material, the guide wire was smoothly inserted into the tube 10 from the insertion port, and even at the meandering point, no permanent deformation of the guide wire was recognized. Loss of torque transmission due to torsion
Although not done, the introduction into the meandering section required a considerable amount of time, and the insertion work was difficult.

On the other hand, according to the present invention, all of them show good results. In particular, in the case of using SuS for the core wire, the permanent deformation in the meandering part of SuS can prevent the permanent deformation of the outer skin of the Ti-Ni alloy superelastic net. As a result, the torque transmission can be maintained and the rigidity can be enhanced. In addition, the flexible portion at the distal end, in which the length can be changed, could be inserted into the meandering portion extremely easily.

[0014]

According to the present invention, Ti-N
Since the helical coil-shaped or net-shaped i-type shape memory alloy is provided, it is possible to have both the rigidity of the substrate portion and the flexibility of the tip portion. Further, according to the present invention, the entirety of the core material is a helical coil or a mesh tube, and only the substrate portion is a core wire of a spring material such as Ti-Ni alloy or stainless steel so that the tip portion and the substrate portion are integrally formed. As a result, a catheter guide wire with improved torque transmission, flexibility at the distal end, and increased rigidity at the matrix portion can be obtained. Furthermore, the length of the flexible portion can be controlled by arbitrarily moving the core wire constituting the substrate portion in the tube.

[Brief description of the drawings]

FIG. 1A is a sectional view showing a configuration of a helical coil and a core wire of a distal end portion of a catheter guide wire and a substrate portion. (B) is a cross-sectional view showing the configuration of a reticulated tube and a core wire at the distal end portion and the substrate portion of the catheter guide wire.

FIG. 2 is an explanatory diagram showing an operability test.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Ti-Ni helical coil 2 ... Ti-Ni helical coil 3 ... Core wire of Ti-Ni, SuS, etc. 10 ... Transparent tube used for operability test

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) A61M 25/01 A61M 25/00 306

Claims (2)

(57) [Claims] 1. A tip portion and a substrate portion integrally formed with each other.
And a catheter guide wire wire having
Outside the core wire, the tip is super-elastic at in vivo temperature.
A catheter guide wire, wherein the Ni-based shape memory alloy is arranged in a helical coil shape or a net shape. 2. The above-mentioned wire rod , wherein the substrate portion is formed of a helical coil or mesh tube of a Ti—Ni based shape memory alloy exhibiting superelasticity at a temperature in a living body, and the substrate portion is inside the tube. Stainless steel only or T
A core wire of an i-Ni alloy is provided.
The catheter guidewire according to claim 1 .