JPH10155913A - Guide wire for catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catheter guide wire having a wire end part capable of properly transmitting torque, largely bending along any direction upon exposure to a small force, and giving extremely large bending resistant strength when bent to a maximum limit by forming a braided assembly of the prescribed length of metallic wires on the guide wire end. SOLUTION: A guide wire for a catheter is made of a linear body 1 of high tension metal, and a braided assembly 2 as cylindrically braided by use of extra fine X-ray impermeable metallic wires, and capped and fixed to the forward end of the linear body 1 via one end thereof. At the same time, the extra fine metallic wires to form the braid assembly 2 are shaped into a head piece having smooth projected surface 21a at a heating and melting process, with the required length of the end 21 of the braided assembly 2 left in the end extension direction of the linear body 1. Then, the braided assembly 2 is capped to the forward end 1a of the linear body 1, and a brazing material 3 is made to infiltrate into a joint, thereby jointing the linear body 1 and the braided assembly 2 to each other. In addition, the external surface of at least the linear body 1, or the linear body 1 and the braided assembly 2 is covered with a synthetic resin film 4 and when necessary, the film is coated with a lubricating material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a guide wire for a catheter for introducing a catheter for treatment or examination into a target site in a blood vessel, a digestive tract or a trachea (hereinafter referred to as a lumen of a blood vessel or the like). .

[0002]

2. Description of the Related Art When treating or examining a site where surgery is difficult, a guide wire for a catheter is housed in a catheter after a doctor or the like imparts a slight bending habit to the distal end thereof in advance, and the distal end of the catheter is used. As a guide to introduce a catheter to a target site in a lumen such as a blood vessel by projecting a few cm, so that a doctor slightly applies a reciprocating rotational force (twist) to the proximal end of the guide wire. It is inserted into a lumen such as a blood vessel. As the operation method, other parts of the lumen such as blood vessels apart from the target part are secured by the Seldinger method or the like, and from here,
Insert the distal end of the guide wire, pass through the meandering part of the lumen such as a blood vessel, or pass through the stenosis, or select and enter the branching point in the desired direction. The guide wire is pulled out. In addition, a guide wire may be left at the target site as an aid when a balloon such as a dilatation catheter is expanded.

[0003] The treatment or examination involves performing a necessary treatment such as injecting a drug solution or an X-ray contrast agent through a catheter. After the treatment, the catheter is withdrawn and the blood pressure is stopped.

However, the distal end of the guide wire is bent so as to search for a meandering state of a lumen such as a blood vessel using a twisting operation at a proximal end of the guide wire and a bending habit attached to the distal end in advance. This is a vital part of a guide wire that plays a leading role in entering a desired branch pipe earlier than when entering a branch point of a lumen such as a blood vessel, and ensures a rotational force (torsion). , Flexibility with a weak waist, and bending resistance in a constant bending state are required with sufficient safety and reliability.

If the torsion applied to the proximal end of the guide wire is not transmitted accurately, it is difficult to perform a selective approach operation at a branch point of a lumen such as a blood vessel, and the distal end of the guide wire is strong. Or, when there is no bending resistance in a certain curved state, it is difficult to enter a meandering part of a lumen such as a blood vessel.

[0006] However, a conventional catheter guide wire is made of a metal linear member made of either stainless steel or piano wire and a stainless steel, platinum, or platinum alloy that covers the vicinity of the distal end of the linear member or over the entire length. It consisted of a coil spring made of.

[0007]

When the distal end of the guide wire is formed of a coil spring, a) Since the twisting operation at the proximal end of the guide wire is not accurately transmitted to the coil spring, a lumen of a blood vessel or the like is not transmitted. It is difficult to perform a selective approach operation at a branch point.

B) When the coil spring is bent, a large gap is formed between the composition metal wires on the outside of the curve. If the curve is excessively increased due to the advance of the guide wire, the gap between the curved coil wire and the coil wire is easily formed. And the subsequent progress of the guide wire becomes very difficult.

C) Further, there is a possibility that the composition metal wire of the coil spring is broken.

[0010] There is a drawback.

The present invention has been devised in view of the above points, and can transmit torque reliably, can be greatly bent in any direction with a small force, and is extremely large when fully bent. An object of the present invention is to provide a guide wire for a catheter having a guide wire tip having bending resistance.

[0012]

A guide wire for a catheter according to the present invention is characterized in that a distal end portion thereof is provided with a braided body woven by a metal wire having a predetermined length.

The braid has the following characteristics with respect to torsion and bending as compared with the conventional coil spring.

A) The torque (torsion) can be transmitted while maintaining the curved state. The torque that can be transmitted is extremely large. Coil springs can hardly transmit torque.

B) When fully bent, it is supported by the tensile strength of the composition metal wire outside the curve,
The bending resistance is extremely large. Moreover, even if the braid is bent, a large gap does not occur between the composition metal wires outside the curve.

Therefore, according to the guide wire for a catheter of the present invention, a guide wire is introduced into a lumen of a blood vessel or the like as a guide for introducing a catheter to a target site within the lumen of a blood vessel or the like upon treatment or examination. Insert.

In this case, since the distal end portion of the braid has a required length in the direction in which the distal end of the linear body extends, the doctor wire or the like is required to insert the guide wire prior to insertion into a lumen such as a blood vessel. A slight bending habit is given to the front half of the braid. At the time of insertion, the doctor slightly applies a reciprocating rotational force (twist) to the proximal end of the guide wire, that is, the proximal end of the linear body.

Then, the rotational force is transmitted to the braided body without fail. The braided body to which the rotational force is applied enters while bending to search for a winding state of a lumen such as a blood vessel. This is because, as mentioned above, the braid is
This is because the wire can be largely bent in any direction and can be easily restored when a bending force opposite to the bending direction is applied from the inner wall of a lumen such as a blood vessel due to the progress of the guide wire.

In order to allow the braid to enter a desired branch pipe before entering the bifurcation of a lumen such as a blood vessel, it is necessary to observe the braid with an X-ray contrast apparatus while observing the braid externally. Twist the base end of the wire at the required angle and shift the bending side of the front half of the braid provided in advance when inserting the guide wire in the direction of rotation with respect to the wire axis so that the distal end of the braid is directed toward the desired branch pipe. It is sufficient to continue the approach of the guide wire.

According to the present invention, it is easy and easy to direct the tip of the braid toward the desired branch pipe, because the braid can reliably transmit the rotating force while maintaining the curved state as described above. Can be performed well.

In the guide wire for a catheter, for example, the braided body is covered and fixed from one end to a distal end side of a linear body made of a high-tensile metal, and the distal end of the braided body is fixed to the linear form. It has a predetermined length in the extension direction of the tip of the body.

In the catheter guide wire, for example, the braided body is fixed to one end of a linear body made of a high-tensile metal from one end, and the distal end of the linear body is at the front end. It has a smaller diameter toward the inside and is passed through the inside of the braided body.

Preferably, the metal wire constituting the braid is a radiopaque metal wire.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A guide wire for a catheter according to the present invention will be described below in detail with reference to the accompanying drawings.

FIGS. 1 to 4 are sectional views showing different embodiments of the guide wire for a catheter of the present invention.

First, in the first embodiment shown in FIG. 1, a linear body 1 made of a high-tensile metal and a finely woven X-ray opaque metal wire are knitted in a cylindrical shape. The braided body 2 covers and is fixed to the distal end side of the linear body, and the distal end portion 21 of the braided body 2 has a required length in the direction in which the linear body extends in the distal end thereof to constitute the braided body 2. The thin metal wire is heated and melted to form a head piece having a smooth convex curved surface 21a.

[0027] A tubular braided body 2 woven from a fine X-ray opaque metal wire is fitted on the tip 1a of the high-strength metallic linear body 1, and then the brazing material 3 is placed on the fitting portion. The braid 2 is penetrated and mutually fixed, and the tip 21 of the braid 2 is
Is heated and melted to form a head piece having a smooth convex curved surface 21a. At least the outer surface of the linear body 1 or the linear body 1 and the braided body 2 is a synthetic resin film. 4, and further, if necessary, a lubricity imparting agent (unsigned) is coated on the outer surface of the synthetic resin.

More specifically, the linear body 1 is made of stainless steel (preferably, high-tensile stainless steel for spring), piano wire (preferably, nickel-plated or chrome-plated piano wire) or superelastic alloy. (Preferably, a Ni-Ti alloy, a Cu-Al-Ni alloy, Cu
-Zn-Al-based alloy) is a high-strength metal wire having a perfect circular cross section, particularly straightened, and its diameter and length are variously large and small depending on the application. Diameter d
Is 0.2 to 1.8 mm (preferably 0.25 to 1.0 mm)
mm), and the length l is 30 to 3,500 mm
(Preferably 50 to 3,000 mm).

The straightness processing is performed on the linear body 1 in order to make the linear body 1 hard to bend, and when the guide wire is inserted, the distal end of the braided body 2 is connected to a tube such as a blood vessel. To be able to accurately transmit the operation (hand operation) at the base end of the guide wire, which is performed when operating, pushing, or rotating in the desired direction in the cavity, to the distal end side In order to facilitate insertion.

The synthetic resin film 4 covering the linear body 1 or the linear body 1 and the braided body 2 is made of a thermoplastic synthetic resin (for example, fluororesin or thermoplastic polyurethane). (Liquid immersion pulling method) to form a coating with a uniform desired thickness. Further, in the case other than the fluororesin, it is preferable to coat a lubricity imparting agent on the outer surface of the synthetic resin film 4 in order to improve the slipperiness on the surface, and the lubricity imparting agent coated on the outer surface of the synthetic resin film 4 is preferably used. The agent, for example, is a water-soluble polymer substance or a derivative thereof that is slimy on contact with water,
The thickness is a few microns to a few hundred microns, which can reduce the frictional resistance with the inner surface of the catheter or the blood vessel wall. In this case, a material having a reactive functional group is selected for the synthetic resin film 4, and the lubricity imparting agent is
It is preferable to select a substance that covalently binds to the reactive functional group in order to make it impossible for the lubricity-imparting agent to be released or outflow.

The braided body 2 is made of one or several kinds of ultrafine X-ray opaque metal wires such as Pt, Pt alloy, Ag, Ag alloy, W, W alloy or stainless steel having a diameter of several to several tens of microns. Using a large number, the outer diameter of the linear body 1
It is knitted in a cylindrical shape by a special machine so as to be approximately equal to the diameter of.

The braid 2 has a required length in the direction in which the end of the linear body 1 extends, and the length 1 is 0 <l ≦ 50.
(Mm).

The convex curved surface 21a is not limited to a hemispherical surface, but it is sufficient that the distal end of the tubular braid 2 such as a hanging bell shape or a bullet shape is smoothly closed. The convex surface 2
1a is formed, for example, by instantaneously melting the tip of the braided body 2 by a heating device and forming a hemispherical shape, a bell shape, or a bullet shape by the surface elasticity of the melted metal.

The braided body 2 has a tip portion 21 having a required length in the direction in which the linear body extends, and heats and melts an extremely fine metal wire constituting the braided body 2 to form a smooth convex. Curved surface 21
Since it is formed in the shape of a head piece having a, it enters without hurting the blood vessel wall while bending so as to search for a winding state of a lumen such as a blood vessel.

In the second embodiment shown in FIG. 2, the distal end 11 of the linear body 1 is passed through the inside of the braid 2 in a tapered shape having a small diameter toward the distal end, and the convex curved surface 21a of the braid 2 is formed. Is extended to the vicinity of the tip portion 21 formed in the shape of a head piece having the following shape, and the tip portion 1 a of the tip side 11 of the linear body 1 is fixed to the braided body 2 by penetrating the brazing material 5. , Is different from the first embodiment.

In this case, the tip 1a on the tip side 11 of the linear body 1 extends to the tip 21 of the braided body 2, and when the tip 21 is processed into a convex shape, it is simultaneously melted and connected. May be.

The front end 11 of the linear body 1 is fixed inside the braid 2 and through the front end because the braid 2 preferably has a moderate waist (restore straightness). Sex). When the distal end portion 1a of the distal end side 11 is terminated before the distal end portion 21 of the braided body 2, when inserting the guide wire, the doctor in advance
This is to make it easier to impart a bending habit at the tip of the. The distal end 11 of the linear body 1 is formed in a tapered shape having a smaller diameter toward the distal end, and the flexibility is increased as the distal end of the guide wire. This is because it is preferable to follow a delicate operation of the guide wire and to enter along a meandering in a lumen such as a blood vessel.

In the third embodiment shown in FIG. 3, a linear body 1 made of a high-tensile metal and an extra-fine X-ray opaque metal wire are knitted in a cylindrical shape. The linear body 1 is made of a braided body 2 covered and fixed on the side, and the linear body 1 is made of a metal material having substantially the same diameter and different metal materials.
And the distal core 112 are connected so as to form a single line by a connecting body 113 made of a metal material different from these cores so as to wrap the whole of the proximal core 111 and a part of the distal core 112. The core 112
However, a tapered portion having a smaller diameter toward the tip is passed through the inside of the braided body 2, and extends to or near the tip end portion 21 formed in a head piece shape having a convex curved surface 21 a of the braided body 2, The distal end 112a is the distal end 2 of the braided body 2.
In the case where the wire ends at a position before the wire 1, the tip 112a of the tip-side core 112 of the linear body 1 is fixed to the braided body 2 by penetrating the brazing material 5.

The base end core 111 is made of stainless steel or piano wire having a high tensile strength to secure the stiffness of the linear body (the pushability of the guide wire and the torque transmission to the front end core 112). The distal core 112 employs a superelastic alloy to secure a weak waist in addition to the flexibility of the braid 2 at the distal end of the guide wire. The superelastic alloy is N
i-Ti alloy, Cu-Al-Ni alloy, Cu-Zn
-Al alloys and the like are suitable.

The connection between the proximal core 111 and the distal core 112 by the connection body 113 is a crimp-coating structure because the connection between the proximal core 111 and the distal core 112 is performed by a method such as soldering, brazing, or welding. Because it is difficult to achieve. That is, the elastic elongation of ordinary metal is 2%
The superelastic alloy has an extremely high value (Ni-T
6-8% for i-based alloys), welding with dissimilar metals,
Brazing is practically difficult. Further, even if welding or brazing is possible, the superelastic properties are lost due to heat during welding and brazing. Therefore, high joining strength and superelastic properties can be ensured by press-fitting a stainless steel tube onto the end of the superelastic alloy.

The connecting body 113 is formed by pressing and covering both the base-side core 111 and the distal-side core 112 to form the base-side core 111.
And the core 112 on the distal end side is secured.
13 is preferably stainless steel or the like.

The production of the linear body 1 composed of the base core 111, the distal core 112 and the connector 113 is performed by
After inserting a stainless steel wire as the proximal core 111 and a superelastic alloy as the distal core 112 into the inside diameter of the stainless steel pipe corresponding to No. 3 to form a coaxial structure (for example, the outer diameter corresponding to the connecting body 113). 0.5mm, 0.4mm inside diameter
After inserting a 0.25 mm stainless wire as the proximal core 111 and a superelastic alloy having an outer diameter of 0.25 mm as the distal core 112 into the inner diameter of the stainless steel pipe from the side of the proximal core 111 It is drawn through a die and drawn, and this is performed in several steps to obtain a required outer diameter.
Therefore, the connecting body 113 is strongly adhered to the proximal core 111 and the distal core 112, and the connection between the proximal core 111 and the distal core 112 can be secured strongly.

A fourth embodiment shown in FIG.
2, the braided body 2 has a tip similar to that of the second embodiment shown in FIG.
The third embodiment shown in FIG. 3 is that the end portion 1a of the linear body 1 is fixed to the braided body 2 by penetrating the brazing material 5 to the vicinity of the end portion 21 of the linear body 1. It is different from the example.

[0044]

The catheter guide wire of the present invention described above has a structure in which the distal end portion is provided with a braid woven by a metal wire of a predetermined length.
The ability to transmit torque while maintaining a curved state; b)
The ability to bend in any direction with a small force; c)
Based on possessing the function of having extremely large bending force when fully bent, a doctor gives a slight bending habit to the front half of the braided body in advance, when treating or examining, As a guide for introducing a catheter into a target site in a lumen such as a blood vessel, a doctor applies a slight reciprocating rotational force (twist) to the proximal end of the linear body while the braided body is inserted into a lumen such as a blood vessel. When it is inserted inside, the rotational force (torsion)
Is reliably transmitted to the braided body, and the braided body can enter while bending to look for a winding state such as a blood vessel. Also, even when the braid enters a desired branch pipe before entering the bifurcation of a lumen such as a blood vessel, the rotational force can be reliably transmitted while the braid maintains a curved state. By giving a slight bending habit to the front half of the body, it can be easily and well performed.
In other words, the rotational force (torsion) is reliably transmitted to the braided body by twisting the base end of the linear body by a required angle while externally observing with an X-ray contrast device, and the rotational force (torsion) is previously determined in accordance with the rotational force (torsion). The tip of the braid can be very accurately directed in the direction of the desired branch pipe by utilizing the bending habit of the front half of the provided braid, so that the guide wire is advanced into the desired branch pipe. be able to.

In addition, the guide wire for a catheter is fixed to the distal end side of a linear body made of a high-tensile metal so that the braided body covers one end thereof, and the distal end side of the linear body faces the distal end. If the diameter is small and the braided body is passed through the inside of the braided body, the braided body can have an appropriate waist (straightness restorability) and the flexibility increases as the distal end portion of the guide wire increases. In accordance with the delicate operation of the guide wire, the braided body can satisfactorily enter along the tortuosity in a lumen such as a blood vessel.

If the metal wire constituting the braid is an X-ray opaque metal wire, the position of the braid, that is, the position of the tip of the guide wire can be confirmed by an X-ray contrast device, and the guide wire entry operation can be performed. Can be performed favorably.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a guide wire for a catheter of the present invention.

FIG. 2 is a sectional view showing a second embodiment of the guide wire for a catheter of the present invention.

FIG. 3 is a sectional view showing a third embodiment of the guide wire for a catheter according to the present invention.

FIG. 4 is a sectional view showing a fourth embodiment of the guide wire for a catheter according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Linear body 111 Base-side core 112 Tip-side core 113 Connected body 2 Braided body

Claims (4)

[Claims] 1. A guide wire for a catheter, comprising a braided body made of a metal wire having a predetermined length at a distal end portion. 2. The braided body covers and is fixed to one end of a linear body made of a high-strength metal from one end, and the distal end of the braid has a predetermined length in a direction in which the linear body extends. The guide wire for a catheter according to claim 1, which is present. 3. The braid, wherein the braided body is fixed to a distal end side of a linear body made of a high-tensile metal from one end thereof, and the distal end side of the linear body has a smaller diameter toward the distal end. The catheter guide wire according to claim 1, which is passed through the inside of the body. 4. The guide wire for a catheter according to claim 1, wherein the metal wire constituting the braided body is an X-ray opaque metal wire.