JPH0956822A - Medical guidewire - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] At the tip of the core material 2 of an ultrafine wire mainly composed of wire,
In the medical guide wire 1 in which the distal end portion 4 is formed by fitting and mounting the coil spring 3, the insertability into a blood vessel and a branch blood vessel is improved, and at the same time, prevention of insufficient blood flow when inserting the guide wire 1 and a balloon. Improve the treatment with catheters. A coil spring (3) is formed into an elliptic coil spring composed of an elliptic coil (5) having a major axis (D1) and a minor axis (D2), and a front half portion (7) of an axial center tip part (6) of a core material (2) is major axis having a major axis (D1). The structure is characterized in that it is formed on the shaft 15 and wide in the direction of the major axis D1 and is formed into a strip-shaped plate, and the side edge of the front half portion 7 and the inside of the coil spring 3 are joined and fitted.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a medical guide wire used for introducing a catheter into the cardiovascular system.

[0002]

2. Description of the Related Art For the purpose of angiography, a catheter of an extra-fine flexible tube is inserted into a blood vessel, or a balloon catheter is inserted into a blood vessel for treating a blockage site of a coronary artery. A medical guide wire made of a flexible wire is used in order to ensure the secure insertion of the wire, and there are known examples disclosed in Japanese Patent Publication Nos. 4-25024 and 4-292175.

The medical guide wire 1 (hereinafter, simply referred to as the guide wire 1) has a tortuous and complicated blood vessel 12 and a branched blood vessel 1 (see FIGS. 3 and 4).
3 is inserted from the distal end portion 4 into the blood vessel, so that flexibility and vertical load resistance (buckling resistance) against the load in the traveling direction are required, and further, the proximal end 14 located outside the body is rotated into the blood vessel. Since it is inserted and advanced, it is necessary to have a mechanical property having a torsional rigidity that is appropriate for the rotation thereof and a steering property that the direction of the distal end portion 4 in the blood vessel can be manipulated by operating the proximal end 14. It has a basic structure in which a coil spring 3 is fitted and attached to a core material 2 of an ultrafine wire which is mainly a wire.

That is, for example, in the case of insertion into a branch blood vessel 13, a part of the distal end portion 4 is plastically deformed into a dogleg shape with a fingertip or the like to form a waist bent portion 11 which is inserted into the blood vessel, and the waist bent. When the portion 11 reaches the vicinity of the branch point of the branch blood vessel 13 to be inserted, the guide wire 1 is rotated to rotate the waist bending portion 1
1 is introduced into the branch blood vessel 13, and the guide wire 1 can be smoothly inserted into the branch blood vessel 13 by the introduction operation.

Therefore, in order to facilitate the operation of introducing the branch blood vessel, the waist bent portion 11 is easily formed and the shape stability is excellent, and the tip portion 4 having the waist bent portion 11 is
A bending characteristic that allows easy bending in only the bending direction of the waist bending portion 11 and that has bending rigidity in a direction other than the bending direction that allows easy uniaxial bending is preferable. There is a guide wire disclosed in Japanese Patent Laid-Open No. 4-292175 (see FIG. 4), in which the core material 2 at the distal end portion is flattened in the uniaxial direction to "wide front end / narrow rear width".
This duckbill-shaped core material 2
It has a structure in which the coil spring 3 of a perfect circular coil is fitted and attached to the tip portion 6 of the core material.

[0006]

The guide wire 1 of the duck bill-shaped core material of the above-mentioned known example has the above-mentioned bending characteristic that the distal end portion 4 facilitates the introduction into the branch blood vessel. The size of the coil spring 3 is extremely small, and the core member 2 has a structurally low contribution to the bending characteristics of the entire tip portion 4. Therefore, the wide portion of the duckbill shape is considerably enlarged. If not set, the above bending characteristics cannot be mechanically satisfied.

Therefore, the tip end portion 6 of the core material is enlarged, and the diameter of the coil spring 3 is inevitably increased.
In order to satisfy the vertical loadability of the guide wire, the duckbill shape has to be made quite large. Therefore, due to the enlargement of the shape of the distal end portion 4 due to this enlargement, the intravascular insertability of the guide wire 1 is hindered. At the same time, it becomes difficult to treat the vascular stenosis due to balloon bulging or the like. Then, the distal end portion 4 occupies a large intravascular cross-sectional area, which causes a problem of insufficient blood flow when the catheter is inserted.

The present invention provides a guide wire that solves the above-mentioned drawbacks of the prior art.

[0009]

The medical guide wire of the present invention which solves the above technical problems is described in "A medical guide wire in which a coil spring is fitted and attached to the distal end portion of a linear core mainly composed of a guide wire. The coil spring is composed of an elliptical coil or an elliptic coil having a major axis in the same direction, and has a structure in which at least a part of the inner circumference of the coil is joined to the edge of the core material.

That is, in the guide wire of the present invention, by making the coil spring to be fitted and fitted into the elliptical coil or the elliptical coil, the tip portion can be easily bent in the uniaxial direction of the ellipse / oval in the minor axis direction. In order to secure the concentric coupling between the coil spring and the core material, the coil spring is provided with appropriate bending rigidity in a direction other than the uniaxial direction so as to obtain the preferable bending characteristics. The inner periphery of the core and a part of the edge of the core are joined and combined and fitted. Then, the core material adopts a free shape such as a round wire shape with a diameter difference step or a flat shape as long as it does not impair the bending characteristics of the coil spring. So that the inner position can be recognized by radiation from outside the body,
Part of it is formed of a radiopaque material.

[0011]

In the guide wire of the present invention having the above-mentioned structure, the coil spring which governs mechanical properties such as flexibility, rigidity and bending characteristics of the distal end portion of the guide wire is composed of an elliptical coil or an oval coil. Therefore, it is easy to bend only in the uniaxial direction of the minor axis direction of the ellipse / oval, and it is necessary to give the tip part sufficient bending characteristics unique to the flexural rigidity in directions other than the uniaxial direction. can do. The peculiar bending characteristics can be set considering the diameter of the elliptical coil or the oval coil within the allowable value range and the coil wire diameter, coil pitch, etc., and the core material existing in the central space of the coil spring. As for the above, a free shape having a proper vertical load property can be adopted without restraint due to the bending property, and without causing harmful shape enlargement. Therefore, the bending characteristics can be imparted without causing the shape of the tip portion to be enlarged.

In the state of insertion into the blood vessel, since the blood flow path can be secured on the short diameter side of the elliptical coil (oval coil), insufficient blood flow due to insertion of the guide wire can be prevented. .

[0013]

Embodiments will be described in detail below based on embodiments. First, referring to FIG. 1 showing a guide wire 1 of a first embodiment of the present invention, a core material 2 mainly composed of an ultrafine wire having a diameter of approximately 0.35 is used and a tip portion of the core material 2 is formed. To 6,
A coil spring 3 is fitted and attached to form a catheter tip portion 4 (hereinafter, simply referred to as a tip portion 4) which serves as a leading portion when a blood vessel is inserted. In the coil spring 3, the elliptic coil 5 having a major diameter D1 and a minor diameter D2 is used. Is a continuous elliptical coil spring with the major axis D1 in the same direction.

The tip portion 6 of the core material 2 into which the coil spring 3 is fitted and attached is made into the tip portion of the core material 2 of the ultrafine wire which is mainly the wire of the guide wire 1.
And a rear half portion 8 having a notched circular shape with the circumference cut out in a parallel plane, and the front half portion 7 has a strip-shaped direction parallel to the major axis D1
The side edge 9 is joined to the inside of the elliptical coil 5 and is internally provided on the major axis 15, and the rear half 8 is provided with the inside of the elliptic coil 5 and the space 10.
Is internally fitted in the hollow portion of the coil spring 3 via. The tip 6 of the core material satisfies the vertical load required for the core 2 and also functions organically in conjunction with the coil spring 3 to satisfy the flexibility and bending characteristics required for the tip portion 4. It has a shape.

The coil spring 3 of this embodiment is used.
Is a total length L: about 300 grits, major diameter D1: 0.325 grits, minor diameter: 0.245 grits, wire diameter of the elliptical coil 5: 0.065
The coil spring 3 has a size of a slag, and about 20 stalks of the tip end are made of a radiopaque material "platinum-nickel alloy wire", and portions other than the tip end are made of a radiation transmission material "austenitic stainless wire". Has been formed,
The position of the distal end portion 4 inserted into the blood vessel and the direction of the waist bending portion 11 can be recognized by the radiation from the outside of the body. Reference numeral 17 in the figure denotes a round soft head provided at the tip of the core material tip portion 6 for preventing blood vessel damage.

The catheter 1 of the embodiment shown in FIG. 1 has the above-mentioned effect. That is, the front half portion of the tip portion 4 has the front half portion 7 of the strip-shaped core material 2 having a strip width in the major diameter D1 direction of the elliptical coil spring 3, so that the major axis 15 serves as a bending neutral surface. Easy to bend in the D2 direction and has a short diameter D
In directions other than the two directions, the coil spring 3 having the major axis D1
And the bending resistance of the first half portion 7 are weighted to make it difficult to bend, and there is an appropriate bending rigidity. Therefore, the branch blood vessel 13
When it is inserted into, the waist bend 11 is easily formed, and the bent shape of the waist bend 11 is less likely to collapse in a direction other than the bending direction, and the shape is stable.

When guiding the waist bending portion 11 to the branch portion of the branch blood vessel 13, even if the proximal end 14 of the guide wire 1 existing outside the body is rotated and operated, the waist bending portion 1
Since there is an appropriate bending rigidity in a direction other than the bending direction of 1, the waist bending portion 11 does not fluctuate, the direction of the distal end portion 4 to the branch blood vessel 13 can be easily determined and guided, and good steering performance can be obtained.

Further, the guide wire 1 of the embodiment shown in FIG.
Since the major diameter D1 of the coil spring 3 is set to a size that does not impede the intravascular insertion property, and the shape that satisfies the above bending characteristics can be selected by selecting the coil pitch and the wire rod system, the inside diameter of the coil spring 3 can be increased. In addition to preventing a decrease in insertability and treatment difficulty, a blood flow path can be secured between the outer circumference of the coil having the short diameter D2 and the blood vessel wall in the intravascular insertion state. It can be prevented.

Further, in the guide wire 1 of the present invention and the conventional guide wire 1, the coil pulling 3 has the same conditions except for the difference between a true circular coil and an elliptic coil having the same maximum outer diameter. When the bending actions are compared with each other, the bending curvature of the distal end portion 4A of the present invention is smaller than that of the conventional distal end portion 4B by the bending in the minor axis direction, and the distal end functions as a leading portion of the intravascular introduction guide. The performance of the part 4 is relatively improved. Further, by improving the performance, it is possible to further reduce the diameter of the tip portion 4 and improve the insertability into the blood vessel.

The guide wire 1 of the present invention is not limited to the above embodiment, but the coil pulling 3 may be an elliptic coil spring composed of an elliptic coil 16 as shown in FIG. The portion 6 is formed into a stepped rod shape having a reduced diameter shoulder portion, and the bending stress is intentionally concentrated on the shoulder portion to make the bending characteristic of the tip end portion 4 unique, or by a taper connection. There is a change in the shape of a rod body having a different diameter, and the free end shape of the core body tip portion 6 is adopted.

[0021]

As described above, in the medical guide wire 1 of the present invention, in which the coil spring is fitted and attached to the distal end portion of the ultrafine wire core material, the insertability into a blood vessel / branch blood vessel is improved. In addition, there is no obstacle to endovascular treatment due to enlargement of the shape, the performance of the guide wire is improved, and at the same time, there is an effect of preventing insufficient blood flow at the time of inserting the guide wire and improving the therapeutic property.

[Brief description of drawings]

1 shows a medical guide wire according to a first embodiment of the present invention, (A) is a front view thereof, (B) is a side view thereof, and (C).
Is a cross-sectional view of FF in (A), (D) is a cross-sectional view in GG of (A),
(E) is an explanatory view of the action of the tip portion

FIG. 2 is a cross-sectional view of a distal end portion of a medical guide wire according to another embodiment of the present invention.

FIG. 3 is an explanatory diagram of how to use the medical guide wire.

FIG. 4 shows a conventional medical guide wire, (A) is a front view thereof, and (B) is a side view thereof.

[Explanation of symbols]

 1 Medical Guide Wire 2 Core Material 3 Coil Spring 4 Tip Part 5 Elliptical Coil 6 Core Material Tip 7 Front Half 7 Half Half 9 Side Edge 10 Void 11 Waist Break 12 Blood Vessel 13 Branch Blood Vessel 14 Base 15 Long Diameter 16 Long coil

Claims (3)

[Claims] 1. A medical guide wire in which a coil spring is fitted and attached to a distal end portion of a linear core mainly composed of a guide wire, wherein the coil spring has an elliptical coil or an oval coil having a major axis in the same direction. And a medical guide wire having a structure in which at least a part of an inner circumference of the coil is joined to an edge portion of the core material. 2. A strip-shaped plate body is formed with at least a part of a tip end portion of a core member into which a coil spring is fitted and mounted, and a side edge of the strip-shaped plate body is joined to a coil inner side on a major axis side of the coil spring. The medical guide wire according to claim 1. 3. A part of the coil spring or a part of the tip of the core material is formed of a radiopaque material.
Alternatively, the medical guide wire according to claim 2.