JPH11178930A - Medical guide wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce slide resistance of a guide wire against the inner surface of a catheter, by composing a guide wire to be a guide for guiding a catheter into a body by a main wire part and a helical coil and using a plural wire coil made by at least a combination of two different size outer diameters. SOLUTION: This wire guide is constituted of a main wire 3 comprising a metal wire, a helical coil covering on the outer periphery of the main wire 3, and hemispherical tip end and rear end parts 5, 6 for fixing the main wire 3 and the helical coil 2. As the material for the helical coil 2, main wire 3, tip end part 5, and rear end part 6, stainless steel or tungsten is used. A wire coil made by alternately placing a thin coil 8 and a thick coil 9 is used for the helical coil 2 and the outer diameter ratio of coils 8, 9 is set within a range 50-90%. Thus the contact area of the guide wire and the inner surface of the catheter is reduced to make inserting and extracting the guide wire 1 easier.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guide wire serving as a guide when a catheter is introduced into a body.
More specifically, the present invention relates to a method for reducing the sliding resistance between a catheter and a guide wire and improving the ease of insertion and removal.

[0002]

2. Description of the Related Art Blood vessels for treating and examining affected parts of the body,
A catheter is introduced and placed in the gastrointestinal tract and the like, and a drug solution, a contrast agent, and the like are injected. At this time, insert the guide wire first, and then use the guide wire as a guide.
A method of guiding a catheter to a target site in a body is generally used.

Here, a typical shape of a guide wire will be described with reference to the drawings. FIG. 3 is a sectional view showing the shape and structure of a guide wire of a straight tip type.
The leading end of the main wire (3) is joined to the helical coil (2), which is tapered and covered on the outer periphery, by means such as welding or brazing at the leading end (5) and the rear end (6). I have. A safety wire (4), which is a thin leaf spring, is mounted between the tapered portion (7) and the helical coil (2) for the purpose of maintaining the resiliency of the distal end. It is joined to the tapered portion (7).

A guide wire having such a structure has a flexible portion (12) at the distal end, a flexible transition portion (13) which is a tapered portion on the distal side of the main wire, and a hardness for imparting torque to the guide wire. It is composed of three parts of a main body (14) for holding. The distal end portion (5) is often processed into a hemispherical shape in order to prevent perforation of body tissue when a guide wire is inserted. Various structures have been devised in addition to the above-described guide wire structure. For example,
There is also an example in which the safety wire (4) is omitted, and instead, the tip side taper portion (7) of the main wire (3) is extended to the tip portion (5) and joined and fixed. In addition, the tip of FIG.
A J-type guidewire having a shape for selective insertion into a local area is often used.

Next, a method of inserting a catheter into a body by a guide wire will be described. A basic method is to first insert a guide wire alone to a target site and then insert the catheter into a guide. As a method of inserting a catheter with a weak waist, a guide wire is inserted into the catheter in advance before insertion into the body, and it may be inserted into the body at the same time by reinforcement, and furthermore, the guide wire in the catheter is advanced or pulled back In some cases, the catheter is inserted while the catheter is inserted. Then, after the catheter is inserted to the target site, the guide wire is pulled out to complete the catheter placement. However, conventionally, troubles due to mutual slippage have frequently occurred in both cases where the guidewire cannot be inserted when the guidewire is inserted into the catheter and cannot be removed when the guidewire is pulled out. In particular, the overall length is long, and there are many troubles when inserting a meandering ileus tube, etc.In recent years, the slipperiness with a guide wire has been improved as the outer diameter of the catheter becomes smaller for minimally invasive treatment Was an urgent task.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the conventional problems described above, and it is possible to reduce the sliding resistance between the catheter lumen and a long or thin catheter. An object of the present invention is to provide a medical guidewire that can be easily inserted.

[0007]

That is, the present invention provides a main wire portion made of a metal wire, a helical coil covering the outer periphery of the main wire portion, and a hemispherical shape for fixing the main wire and the helical coil. And a guide wire for guiding a catheter into a body lumen, wherein the helical coil is a multi-strand coil formed by a combination of at least two different outer diameters. Is in the range of 50 to 90%, or the helical coil is composed of a plurality of coils formed by combining a plate coil and a spherical coil, and the ratio of the thickness of the plate coil to the outer diameter of the spherical coil is in the range of 50 to 90%. A medical guidewire according to any one of the preceding claims.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to FIG. The material of the helical coil (2), the main wire (3), the safety coil (4), the tip (5) and the rear end (6) is suitably stainless steel or tungsten, but is not particularly limited. Instead, it is only necessary that the material has moderate elasticity and is excellent in corrosiveness.

The helical coil (2) is a strip coil in which small-diameter coils (8) and large-diameter coils (9) are alternately arranged in order to reduce the contact area with the catheter lumen. If the ratio is 50% or less, there is a possibility that a displacement such as overlapping may occur. If the ratio is 90% or more, a soft catheter may come into contact with the small-diameter coil (8), and the effect may be reduced. It is desirable that the ratio be 50 to 90%, but the ratio is not particularly limited depending on the balance with the processing technique. In addition, small diameter coil (8)
It is also possible to use three coils of two coils and one large-diameter coil (9), which may be selected in consideration of the stiffness and cost of the guide wire, the contact area with the catheter, and the like.

Next, another embodiment of the present invention will be described in detail with reference to FIG. Although the basic configuration and materials are the same as those in FIG. 1, the helical coil (2) is a plate-shaped coil (1).
0) and the cylindrical coil (11) are alternately arranged. If the outer diameter ratio is 50% or less, there is a possibility that a displacement such as overlapping with each other may occur. However, it is desirable that the ratio be 50 to 90% for reasons such as the possibility of contact with the plate coil (10) and the effect being reduced, but it is not particularly limited in view of the balance with the processing technology. In addition, a method of determining the contact area can be easily performed by adjusting the width of the plate-shaped coil. If the width is increased, the contact area can be naturally reduced.

Also, depending on the conditions used in FIGS. 1 and 2, there is a risk that the surface is oxidized or is attacked by body fluids. Therefore, gold or platinum is used as a metal for surface coating with a stable metal thin film. And the like are preferred. The method of coating with a metal thin film is not particularly limited, and examples thereof include vacuum deposition and plating. Similarly, the thickness of the thin film may be any range as long as it meets the above-described purpose, and is not particularly limited. It is effective for improving the slipperiness of the wire. In particular, the method is more preferred when used in applications that come into contact with blood.

[0012]

As described above, in the medical guide wire according to the present invention, the helical coil in contact with the catheter lumen is formed as a strip coil having alternately different outer diameters, or a cylindrical coil and its outer diameter are used. It is extremely useful as a tool that can easily insert and withdraw a guidewire because it reduces the contact area with the catheter lumen by alternately arranging thin plate-shaped coils that are thinner than the coil, thereby reducing slip resistance. is there.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a medical guidewire according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a medical guidewire according to another embodiment of the present invention.

FIG. 3 is a sectional view showing a conventional medical guidewire.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Guide wire 2 Helical coil 3 Main wire 4 Safety wire 5 Tip part 6 Back end part 7 Tapered part 8 Small diameter coil 9 Large diameter coil 10 Plate coil 11 Cylindrical coil 12 Flexible part main part 13 Flexible transition part 14 Main part

Claims (4)

[Claims] 1. Basically composed of a main wire portion made of a metal wire, a helical coil covering the outer periphery of the main wire portion, and a hemispherical end portion for fixing the main wire and the helical coil. A medical guidewire for guiding a catheter into a body lumen, wherein the helical coil comprises a plurality of coils formed by combining at least two different outer diameters. 2. The medical guidewire according to claim 1, wherein the outer diameter ratio of the two different sizes in the helical coil is in the range of 50 to 90%. 3. It is basically composed of a main wire portion made of a metal wire, a helical coil covering the outer periphery of the main wire portion, and a hemispherical end portion for fixing the main wire and the helical coil. A medical guidewire for guiding a catheter into a body lumen, wherein the helical coil comprises a plurality of coils formed by a combination of a plate coil and a cylindrical coil. 4. The medical guidewire according to claim 3, wherein the ratio of the thickness of the plate coil to the outer diameter of the cylindrical coil is in the range of 50 to 90%.