JP2895464B2 - Guide wire for catheter - Google Patents

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 After the treatment, the catheter is withdrawn and the blood pressure is stopped.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]

However, the performance of conventional guidewires is limited, and there is a demand for a guidewire having higher operability.

The present invention has been devised in view of the above points, and can reliably transmit a rotating force, 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.

[0009]

SUMMARY OF THE INVENTION A catheter guide wire according to the present invention comprises a proximal core and a distal core formed separately, and the proximal core and the distal core are connected. An outer surface of the portion is provided with a connecting body for connecting the two by continuously covering the both, and a coil spring of a predetermined length is covered at least on the distal end of the distal-side core.

[0010]

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

1 to 5 show a reference example of the present invention, and FIG. 6 shows an embodiment of the present invention.

First, a first reference example shown in FIG. 1 has a linear member 1 made of a high-tensile metal and a tubular member made of an ultrafine X-ray opaque metal wire. The braid 2 is covered and fixed over the distal end side or the entire length of the linear body, and the distal end portion 21 of the braid 2 has a required length in the direction in which the linear body extends in the distal end direction. The formed ultrafine metal wire is heated and melted to form a headpiece having a smooth convex curved surface 21a.

[0013] A braided body 2 woven from a fine X-ray opaque metal wire into a tubular shape is fitted on the tip 1a of the linear body 1 made of a high-strength metal. 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 braided body 2 has a required length in the direction of extension of the front end of the linear body 1, and its length 1 is 0 <l ≦ 50.
(Mm).

The convex curved surface 21a is not limited to a hemispherical surface, and it is sufficient that the distal end of the tubular braid 2 such as a hanging bell or a bullet 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 distal end 21 having a required length in the direction of extension of the distal end of the linear body, and heats and melts an extremely fine metal wire constituting the braided body 2 to provide 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 reference example shown in FIG. 2, the braid 2 covers the entire length of the linear body 1 and the distal end 21 of the braid 2 has a required length in the direction in which the linear body extends. And the brazing material (unsigned) penetrates over the entire length of the linear body 1 or is interspersed to fix the braid 2 to the linear body 1,
The first reference point is that the synthetic resin film 4 is formed on the outer side of the braided body 2 and, if necessary, a lubricity imparting agent (unsigned) is coated on the outer surface excluding the tip of the braided body 2. It is different from the example. In addition, the base end of the braided body 2
Is heated and melted in the same manner as described above, and the linear body 1 is covered and closed.

In the third reference example shown in FIG. 3, the distal end side 11 of the linear body 1 is passed through the inside of the braided body 2 in a tapered shape having a smaller diameter toward the distal end, and the convex curved surface 21a of the braided body 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. This is different from the first reference example.

In this case, the distal end 1a of the distal end 11 of the linear body 1 extends to the distal end 21 of the braided body 2. When the distal end 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 small 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.

The fourth reference example shown in FIG. 4 has a linear body 1 made of a high-tensile metal and a tubular braid made of an ultra-fine X-ray opaque metal wire. The linear body 1 is made of a braided body 2 covered and fixed on the side, and the linear body 1 has a base end side (core material) 111 having substantially the same diameter and made of a different metal material.
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 connecting body 113 is made 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 connector 113 is formed by press-fitting both the base core 111 and the distal core 112 so as to cover the base 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 consisting 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.

The fifth reference example shown in FIG.
2 is the same as in the third embodiment shown in FIG.
The point that the end portion 1a of the front end side 11 of the linear body 1 is fixed to the braided body 2 by penetrating the brazing material 5 is shown in FIG. It is different from the example.

The embodiment of the present invention shown in FIG. 6 is different from the fifth embodiment only in that a coil spring 2a is employed in place of the braided body.

The distal end of the distal core 112 extends to the vicinity of the distal end 21 of the coil spring 2 a covering the distal core 112, and the distal core 1 of the linear body 1 extends.
The tip of 12 is fixed to the coil spring 2a by penetrating the brazing material 5 from outside the coil spring 2a.

The tip 21 of the coil spring 2a
It is preferable that a structure is adopted in which the safety wire is connected to the distal end of the distal end core 112 by a safety wire to suppress the elongation of the corresponding coil spring 2a.

[0034]

According to the catheter guide wire of the present invention described above, the proximal core and the distal core are abutted, and the connecting portions of the two are connected in an intimately covered state by a connector, and at least the distal core is connected. Since the distal end portion is provided with a coil spring of a predetermined length,
The core is strongly adhered to the proximal core and the distal core, and the connection between the proximal core and the distal core can be secured strongly.

Since the proximal core and the distal core are formed as separate bodies, the proximal core is made of, for example, a linear body having a high tension to secure the stiffness. Also,
The distal core can properly secure the flexibility and weak waist of the distal end of the guide wire by selecting a different material, so that the rotational force can be securely transmitted by the proximal core, and the distal core can reduce the direction in which direction with a small force. Can be greatly curved,
An extremely large bending resistance can be ensured when fully bent, and a guide wire for a catheter having more excellent use performance can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first reference example of a guide wire for a catheter according to the present invention.

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

FIG. 3 is a sectional view showing a third reference example of the guide wire for a catheter of the present invention.

FIG. 4 is a sectional view showing a fourth reference example of the guide wire for a catheter of the present invention.

FIG. 5 is a sectional view showing a fifth reference example of the guide wire for a catheter of the present invention.

FIG. 6 is a sectional view showing an embodiment of the guide wire for a catheter of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Linear body 111 Base end core 112 Front end core 113 Connecting body 2 Braided body 2a Coil spring

Claims (1)

(57) [Claims] 1. A method comprising: providing a base core and a distal core formed as separate bodies, and continuously coating an outer surface of a portion where the base core and the distal core are connected to each other. A guide wire for a catheter, comprising: a connecting body for connecting the both; and a coil spring having a predetermined length covering at least a distal end portion of the distal-side core.