JPH1076014A - Guide wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a guide wire to be highly effective in following the inside of a body fluid conduit curved in a complex form and to make the wire unlikely to undergo plastic deformations. SOLUTION: This guide wire is so designed that a metallic slender rod-shaped core 3 with a taper 3A formed at one end and a metallic auxiliary core 4 are enclosed inside a long coil tube 2 formed by the close winding of an extra fine metallic wire, with both ends of the auxiliary core 4 secured to both ends of the coil tube 2. The core 3 is formed by three or four fine stranded wires. Also, by forming a portion of the fine wire from a shape memory alloy that softens at body temperature, the wire can be enhanced in its follow-up property when inserted into a curved capillary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical guidewire inserted into a body cavity to guide the insertion of the catheter before the catheter is inserted into the body cavity.

[0002]

2. Description of the Related Art When a long synthetic catheter or endoscope is inserted into a diseased part via a body fluid channel of a patient, a metal guide wire is first inserted into the affected part via the body fluid channel. Next, the guide wire is used as a guide core axis, and a catheter or an endoscope channel is coaxially inserted into the affected part. Thereafter, the guide wire is pulled out, a catheter or an endoscope is placed, and a syringe or an inspection instrument is connected to an outer end of the catheter or the endoscope to perform treatment or examination of an affected part.

[0003] As a guide wire, a metal rod-shaped metal core and a metal auxiliary metal core having tapered tapered portions at both ends are accommodated in a long coil tube formed by densely winding a metal ultrafine wire. A structure in which both ends of the metal auxiliary core are fixed to both ends of the coil tube has been manufactured. Both ends of the guide wire have extremely flexible bent tips so that it can be easily inserted into a complicatedly bent body fluid conduit without damaging a living body.

Further, a guide wire formed of a plurality of thin stranded wires and having a resin coating layer formed on the surface of a cored bar having a tapered end portion is used, for example, for guiding an imaging catheter. It is used.

[0005]

However, the conventional guide wire has a problem that since the core metal is formed of a single wire, the flexibility is limited as a whole, the followability is insufficient, and the guide wire is apt to be plastically deformed. there were. For this reason, a long guide wire is inferior in usability and is difficult to be put into practical use.

Further, in the case of a guide wire in which the surface of a stranded wire core is coated with a resin, the twist is released by repeated bending, and the end of the fine wire may be pierced, exposing the end of the fine wire and damaging the human body. There is a problem that the number of times of bending is limited.

SUMMARY OF THE INVENTION An object of the present invention is to provide a guide wire which has high followability in a complicatedly bent bodily fluid conduit and hardly causes plastic deformation. An object of the invention described in claims 6 to 10 is to provide a guide wire capable of reliably preventing an end of a twisted thin wire from being unraveled, in addition to the above object.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a metal rod and a metal auxiliary core having tapered tapered portions at both ends in a long coil tube formed by tightly winding a metal ultrafine wire. In a guide wire accommodating gold and fixing both ends of the auxiliary core bar to both ends of the coil tube, the core bar is formed of a plurality of thin stranded wires.

[0009]

The guide wire according to the present invention has the following functions and effects because the core metal is formed of a thin stranded wire. B) Plastic deformation hardly occurs even when inserted into a bent thin tube. For this reason, insertion at a long distance into the deep part is possible. B) Since the tapered portion is also a stranded wire, it has high durability against repeated use. C) The combination of the material strengths of the fine wires broadens the selection range in which the rigidity can be arbitrarily selected, so that it is possible to use a guidewire having a rigidity suitable for a patient's medical condition.

The guide wire is preferably formed by twisting three or four stainless wires from the viewpoints of securing rigidity, preventing plastic deformation, and durability against repeated bending. Further, when a part of the thin wire is made of a shape memory alloy that softens at body temperature, the followability when the thin wire is inserted into the bent thin tube can be improved. In this case, a core wire made of a shape memory alloy may be inserted through the twist center of three or four fine wires.
Further, when a resin coating layer is formed on the surface of the core metal,
This has the effect of improving the lubricity and improving the insertion workability.

According to a sixth aspect of the present invention, there is provided a guide wire, wherein a resin coating layer is formed on a surface of a metal core formed of a plurality of thin stranded wires and having a tapered end portion. It is characterized in that the tips of a plurality of fine wires are fixed by brazing, welding, bonding or the like. Thereby, the end of the twisted thin wire can be reliably prevented from being unraveled, and the tip can be bent at will.

[0012]

1 to 3 show a first embodiment of the present invention. The guide wire 1 includes a coil tube 2 formed by tightly winding an ultrafine stainless steel wire having a diameter of 0.17 mm, and hemispherical end members 20 and 2 for sealing both ends of the coil tube 2.
0. The coil tube 2 has a length of 3000 mm to 3 mm.
It has a diameter of 500 mm and an outer diameter of 0.89 mm. Coil tube 2
Inside, a thin metal bar 3 and an auxiliary metal core 4 are accommodated in parallel.

The thin metal bar 3 has an outer diameter of 0.43 m.
m, and is formed by twisting three metal thin wires 31, 32, and 33. The metal core 3 is formed somewhat shorter than the coil tube 2 and the auxiliary metal core 4, and one end 3A is a tapered portion, and the tip is brazed 3a.
The other end 3 </ b> B of the metal core 3 is brazed to the inner surface of the end member 20. The auxiliary metal core 4 is a stainless steel strip having a thickness of 0.065 mm and a width of 0.265 mm, and both ends are brazed to the inner surfaces of the end members 20, 20.

Each of the three thin metal wires 31, 32, and 33 is a stainless wire having a diameter of 0.25 mm and is twisted at a twist pitch of 3.9 mm. One end 3A has a length of 100
mm and formed by polishing or grinding. SUS304 with a diameter of 0.20-0.
40 mm, the twist pitch is preferably in the range of 2 mm to 8 mm.

FIGS. 4A to 4F show another embodiment of the metal thin rod-shaped core 3. (A) is formed by twisting the three same metal thin wires 31, 32, and 33 shown in FIG. (B) shows three identical metal thin wires 31, 32, 3
One of the three is made of a nickel-titanium-based shape memory alloy, and is softened at a body temperature of 36 ° C. or higher. (C) shows three thin wires made of the same metal 31, 32, 33.
A core wire 35 made of a shape memory alloy is arranged at the center of the frame, and is composed of a total of four fine wires.

(D) Each of the four fine wires 31, 32, 3 made of stainless steel having a diameter of 0.20 mm and made of stainless steel.
3, 34 are twisted at a twist pitch of 3.9 mm. (E) shows four identical metal thin wires 31, 32, 3
One of 3, 34 is formed of a shape memory alloy. In addition, two of the four thin wires made of the same metal 31, 32, 33, and 34 may be formed of a shape memory alloy. (F) is 4
A core wire 35 made of a shape memory alloy is arranged at the center of the same metal thin wires 31, 32, 33, 34, and is composed of a total of five thin wires.

FIG. 5 shows the second invention. The guide wire 5 according to the present invention is made by forming a polyurethane, polyamide, or PTFE on the surface of a thin metal rod 3 shown in FIGS.
And the like. One end 3A of the thin metal rod 3 is tapered as described above, and the ends of all the thin wires are connected to each other by brazing 3a at the tip. Instead of the brazing 3a, other fusion means such as resistance welding, laser welding, and shield welding can be adopted, and bonding with an adhesive can also be adopted.

The resin coating 6 may be formed by applying or spraying the resin as shown in (a) or by extruding the core metal 3 together with the resin, as shown in (b). 61 and may be formed by heat shrinking at 400 to 450 ° C. Further, as shown in (c), the tape may be formed by winding a tape 62 made of a fluororesin. The guide wire 5 does not include a coil tube and an auxiliary core, and is used mainly by bending the tapered end portion 51 into a desired shape.

The present invention has the following effects. It has been practiced to coat a metal thin rod core made of a single wire with a polyurethane resin and further coat an outer surface with a hydrophilic polymer. In this case, since the insertion resistance is large, it is necessary to increase the thickness of the polymer. In some cases, the thick hydrophilic polymer itself may inhibit the contrast effect of the contrast agent, and this tendency is particularly large for long products.

The product of the present invention has a low insertion resistance, so that the thickness of the polymer can be reduced, so that it has a high sliding property without impairing such an effect, and particularly a long product (for example, 3000 mm).
Above). In addition, when a single wire is coated with a resin, the coating layer is easily peeled off because the surface is smooth. However, when the stranded wire core metal 3 is used as in the present invention, the surface has irregularities. There is an advantage that peeling hardly occurs.

Further, as described in Japanese Patent Publication No. 4-20453, if the surface of the stranded wire core is merely covered with a resin, there is a problem that twisting is unraveled at the time of processing the tapered end portion 51 and it is difficult to manufacture. At the same time, the tapered end portion 51 may be unraveled by repeated bending, and the thin wire may break through the coating and be exposed, thereby limiting the degree or number of bending. Further, when the tapered end portion 51 is bent, directionality is easily generated, and the usability is poor.

However, in the present invention, since the ends of all the fine wires are connected to each other by the brazing 3a, the wires can be freely bent into a desired shape without any direction at the time of bending, and the number of times of bending can be increased. It can increase dramatically. In addition, this operation | movement and effect are the guide wire 1 of Claim 1-5.
This is almost true.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a guide wire.

FIG. 2 is a front view of a guide wire.

FIG. 3 is a sectional view of a guide wire.

FIG. 4 is a cross-sectional view of a core according to another embodiment.

FIG. 5 is an enlarged sectional view of a main part of a guide wire according to a second invention.

[Description of Signs] 1 Guide wire 2 Coil tube 3 Core 4 Auxiliary core 5 Guide wire 6 Coating 31-34 Fine wire 35 Core 3A One end (taper taper) 3a Brazing

Claims (10)

[Claims] An elongated coil tube formed by tightly winding a metal ultrafine wire contains a metal thin bar core and a metal auxiliary core having tapered tapered portions at both ends. A guide wire in which both ends of a cored bar are fixed to both ends of the coil tube, wherein the cored bar is formed of a plurality of thin stranded wires. 2. The method according to claim 1, wherein the plurality of thin lines are:
A guide wire comprising three thin wires. 3. The method according to claim 1, wherein the plurality of thin lines are
A guide wire comprising four thin wires. 4. The guidewire according to claim 2, wherein a part of the fine wire is made of a shape memory alloy. 5. The guide wire according to claim 2, wherein a core wire made of a shape memory alloy is inserted through a twist center of the fine wire. 6. A guide wire comprising a resin coating layer formed on a surface of a cored bar formed of a plurality of stranded wires and having tapered ends, wherein tips of the plurality of fine wires are brazed. A guide wire that is fixed by attaching, welding, or bonding. 7. The method according to claim 6, wherein the plurality of thin lines are:
A guide wire comprising three thin wires. 8. The method according to claim 6, wherein the plurality of thin lines are:
A guide wire comprising four thin wires. 9. The guidewire according to claim 7, wherein a part of the fine wire is made of a shape memory alloy. 10. The resin coating layer according to claim 6, wherein the resin coating layer is formed by applying a resin, spraying, covering a resin tube made of heat shrink, and heat shrinking, or winding a resin tape. And guide wire.