JPH1043305A - Medical guide wire and forming method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To promote smooth insertion into a blood vessel by achieving a higher workability and a stabilization of shape in preshaping work for providing a <-figured bent part at a tip part as insertion leader in insertion into the blood vessel in a medical catheter in which a core line with a terminal thereof as fine-diameter part is wrapped with a resin cover. SOLUTION: In this medical guard wire 1, a tip part is made with a finer diameter than that of a guide wire main part 6 other than the tip part while being of a type of double heads 5A and 5B paired at both ends. Tip parts 5A and 5B are built in a combination of the tip part 5A with a large diameter D2 and the tip part 5B with a small diameter D3, between which a slight diametrical difference exists. Any of the tip parts is selected alternatively to enable preshaping working.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a medical guidewire used for introducing a catheter into a cardiovascular system, and a method for forming the same.

[0002]

2. Description of the Related Art For the purpose of angiography, a catheter having a very fine flexible tube is inserted into a blood vessel, or when a balloon catheter is inserted into a blood vessel in the treatment of an occluded portion of a coronary artery. In order to ensure the safe insertion of the catheter, a medical guide wire made of a flexible wire is used.
There are a number of known examples disclosed in Japanese Patent Publication No. -20453 and Japanese Utility Model Laid-Open Publication No. 7-7652. Then, they have a common shape of a flexible ultrafine wire that can be inserted into a blood vessel, pass a catheter through a guide wire inserted and set in advance in a blood vessel, and make the guide wire function as a guide line, thereby forming a catheter. The distal end is inserted and set at a predetermined position in a blood vessel, and thereafter, only the guide wire is pulled out to perform a predetermined treatment such as angiography.

That is, (see FIG. 5), since the guide wire 1 is inserted into a blood vessel or a branch blood vessel having a meandering complicated path and pushed into the blood vessel from its distal end, it is flexible and has a vertical load resistance (seat resistance) in the traveling direction. Flexibility) is required, especially for the distal end portion where insertion is to be guided, and high flexibility and high flexibility are indispensable. In addition, the direction of the distal end portion is controlled while rotating the proximal end portion that goes out of the body. Since the operation of insertion into a branch vessel or the like is operated, advanced mechanical properties having both appropriate torsional rigidity and steering properties are required.

[0004] In view of the above, Japanese Utility Model Publication No.
No. 3 and the actual Kaihei No. 7-7652 are extra fine core wires 2
The terminal has a circular cross-sectional shape of a uniform diameter in which only a slight length of one of the terminals is narrowed to form a small-diameter portion 4 and the entire length of the core wire 2 including the small-diameter portion 4 is embedded in the resin coating 3. The configuration using a stranded wire as 2 is characterized in that only one of the strands constituting the stranded wire is projected forward and embedded in the resin coating 3.

[0005]

In the conventional structure in which the core wire 2 is provided with the resin coating 3 on the core wire 2, the tip 5 has high flexibility.
Although it is highly flexible and has an insertion progression in a blood vessel, in order to facilitate insertion of the distal end portion 5 into a blood vessel, the distal end portion 5 is photographed with a fingertip immediately before the insertion and plastically deformed to obtain a “U-shape” It is difficult to perform the pre-shaping process in which the "curved portion 8" is provided, and it is used without stopping to obtain the intended shape of the curved portion 8, resulting in a problem that the insertion work becomes complicated due to a decrease in insertability and the pain of the patient increases. In addition, there is an inconvenience that even if the user wants the fine distal end portion 5 due to circumstances such as the vascular obstruction state of the patient, it is not possible to respond immediately.

The present invention provides a guidewire and a method for forming the guidewire, which solve the above-mentioned drawbacks of the prior art.

[0007]

A guide wire and a method of forming the same according to the present invention for solving the above-mentioned technical problems are described as follows. In a medical guidewire in which a portion having the small-diameter portion is used as a distal end portion of a guide wire for guiding insertion into a blood vessel, the distal end portion of the guide wire is thinner than a main portion of the guide wire other than the distal end portion of the guide wire. With a diameter, and a medical guidewire having a structure that exists in a pair at both ends of the linear body ",

[0008] In forming the medical guidewire of the present invention, a chain core is formed in advance by connecting a core wire in which both ends of a required-diameter wire material have a small-diameter portion with a small length at both ends in series by a connector. The core wire is passed through a molding die of a resin extrusion molding device to form a continuous guide wire body that is continuously coated with a resin to embed the chain core wire,
By controlling the passing speed of the core wire of the forming die or the amount of resin extruded from the forming die, the narrow diameter portion is embedded, and the distal end portion of the guide wire having a reduced outer diameter is automatically formed, and thereafter, the guide wire A method for forming a medical guidewire, characterized in that a medical guidewire is formed sequentially and continuously by dividing a continuous body.

That is, the guide wire of the present invention is of a double-headed type having a guide wire tip portion having a small diameter at both ends of the wire, and one of the guide wire tip portions is selectively used, whereby the pre-shaping process is performed. The molding method of the present invention is characterized in that the core wire having a small diameter portion is connected and unified, and is passed through a molding die of a known resin extrusion molding apparatus, thereby forming the pair of guide wires. The guide wire of the present invention having a tip portion is formed continuously and continuously. In addition, the medical guidewire of the present invention has a pair of guidewire distal ends at both ends, a combination of a large diameter portion and a small diameter portion having a small diameter difference therebetween to form a distal end portion having a size suitable for a patient's vascular condition. In some cases, a mode that allows immediate change may be adopted.

[0010] Further, the guide wire of the present invention is used by arbitrarily selecting and using various materials such as a single wire, a stranded wire, a superelastic alloy wire, and a shape memory alloy wire as a core wire.
In the case of using the stranded wire, a mode in which a wire fixing portion in which wires are fixed to each other at the tip of the small diameter portion is adopted. The distal end portions of the guide wires existing at both ends may be formed in a modified cross-sectional shape other than a circular shape such as a rectangular cross section, and may be provided with a bending point that facilitates bending only in one axial direction passing through the axis.

[0011]

The guide wire according to the present invention has a distal end portion having a smaller diameter than the main portion of the guide wire, so that the flexibility and the flexibility are further improved, so that the progress of insertion into the blood vessel is improved.
Since the distal end portions are present at both ends, and the number of times of the pre-shaping process at the time of insertion into the blood vessel is twice, the bent portion 8 is made more appropriate and the blood vessel is inserted more smoothly. Becomes possible. In the embodiment in which the pair of guidewires has a large-diameter portion and a small-diameter portion with a small difference in diameter, when the narrow distal portion is appropriate depending on the vascular condition of the patient, prompt treatment can be performed immediately in response. it can.

Furthermore, in the above-mentioned embodiment using a stranded wire as the core wire, the twisted state is stable even in the small diameter portion, so that peeling of the resin coating due to untwisting of the wire and failure of protrusion of the wire can be prevented. In addition, the guide wire tip portion having the irregular cross section can be easily bent only in one axial direction, and can provide a sufficient bending rigidity in a direction other than the one axial direction, so that the processability of the preshape is improved. As a result, the shape setting of the bent portion 8 is improved, and the bending direction of the bent portion 8 due to the insertion resistance in the blood vessel can be prevented from being disturbed, so that the steering operation such as introduction into the branch blood vessel becomes easy.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a guide wire 1 according to a first embodiment of the present invention will be described in detail with reference to FIG. That is, it has a circular cross-sectional shape of a uniform diameter D in which an ultrafine single-core stainless steel core wire 2 is wrapped with a resin coating 3 such as nylon 12, and a small portion 4 of the end portion of the core wire 2 is formed into a small-diameter portion 4. In a case where the portion where the small diameter portion 4 is present is defined as a guide wire tip portion 5 (hereinafter, simply referred to as a tip portion 5), the tip portion 5 has a diameter D1 of a guide wire main portion 6 other than the tip portion 5. A pair of distal end portions 5A and 5B exist at both ends of the guide wire main portion 6 having a smaller diameter, and a single guide wire 1 is constituted by the distal end portions 5A and 5B and the intermediate guide wire main portion 6. ing.

More specifically, the distal end portions 5A and 5B serve as leading portions when the guide wire 1 is inserted into a blood vessel, and have a small diameter shape which is thinner than the guide wire main portion 6, so that high flexibility and high flexibility are achieved. The diameters D2 and D3 of the paired distal end portions 5A and 5B have a relatively small diameter difference, and one is a large-diameter distal end portion 5A and the other is a small-diameter distal end portion 5B. A double-headed type configuration in which one of the tip portions 5A and 5B is selectively inserted into a blood vessel, or
It has a double-headed configuration in which the pair of tip portions 5A and 5B have the same diameter. In this embodiment, the diameter D1 of the guide wire main portion 6 is approximately 0.87 mm, the diameter D2 of the tip portion 5A is 0.85 mm, and the diameter D3 of the tip portion 5B is D3.
Is 0.70 mm, and the length L of the tip portions 5A and 5B is approximately 18
0 mm, or 0.85 of the same diameter for both tip parts 5A and 5B
These are the dimensions such as abrasion.

The guide wire 1 according to the embodiment shown in FIG. 1 has the above-mentioned action, and has a preshaped attack change of 2 in which the "curved portion 8" is provided at the time of insertion into a blood vessel.
Because of the number of turns, the shape of the bent portion 8 can be made more appropriate, and in the case of the large diameter portion / small diameter portion configuration, the size of the distal end portion 5 suitable for the vascular condition of the patient is changed to immediately respond. Thus, the insertion of the guide wire 1 into the blood vessel is further facilitated.

Next, a guidewire 1 according to another embodiment will be described with reference to FIG. That is, the tip portions 5A and 5B similar to those in the embodiment of FIG. 1 are provided at both ends of the guide wire main portion 6, and the base portions of the tip portions 5A and 5B in the embodiment of FIG. A known twisted wire 13 in which about 3 to 5 strands 14 are twisted is used as the core wire 2 while being connected to the guide wire main part 6, and a part of the end of the twisted wire 13 is twisted. The small diameter portion 4 is reduced in diameter as it is, and has a wire fixing portion 15 in which the wires 14 at the tips of the small diameter portion 4 are fixed to each other. The wire fixing portion 15 of this embodiment is formed by brazing with a gold material or a silver material.

In the guide wire 1 of the embodiment shown in FIG. 2, even when the distal end portion 5 is bent to a small radius of curvature or repeatedly bent in a blood vessel, the strand 14 is untwisted and is separated from the resin coating 3. There is very little possibility that defects such as peeling of the resin coating 3 are prevented, and the performance and quality of the distal end portion 5 are stabilized. The twisted wire structure has the advantage of flexibility and flexibility superior to a single wire having the same diameter. can do.

That is, when a stranded wire and a single wire having the same diameter are compared with each other,
Although the flexibility and rigidity of single wires are generally limited by the material, the twisted wires are more flexible and flexible than single wires, and the range of change in flexibility and rigidity is intentionally set wider by the twisted configuration. it can. Therefore, when a stranded wire is adopted as the guide wire core wire, the variable selection area of the mechanical properties of the guide wire becomes large, and “higher quality” can be obtained. In addition, by improving the insertability into the blood vessel by improving the flexibility of the guide wire, it is possible to reduce the application of a hydrophilic polymer or the like applied to the outer periphery in order to improve the insertability into the blood vessel of the guide wire, and to use the twisted core wire. Since the ridges formed by twisting exist on the outer periphery, the adhesiveness of the resin coating 3 is improved, and there is no possibility that the resin peels due to insertion and bending in the blood vessel, and the performance of the guide wire is stabilized and improved.

Next, an embodiment of a method for forming the guide wire 1 of the embodiment shown in FIG. 1 will be described with reference to FIG. That is, first, the core wire 2 having the small diameter portion 4 at both ends is formed, and the core wire 2 is formed.
Are connected in series by a connecting tool 16 to form a chain core wire 10 continuous to a single linear body. Subsequently, the chain core wire 10 is passed through a molding die 17 of a known resin extrusion molding device to apply the resin coating 3 to the chain core wire 10, and the speed at which the molding die 17 passes or the amount of resin extruded into the molding die 17 is determined. By the adjustment, the guide wire continuum 11 in which the tip portions 5A and 5B of a predetermined shape for embedding the respective small diameter portions 4 are automatically formed is formed.

Thereafter, the guide wire continuum 11
Cut from the place of the connecting tool 16, and then perform a touch-up process of embedding the small-diameter portion 4 of the cut portion in a resin,
The guide wire 1 of the embodiment shown in FIG. 1 in which the entire shape of the core wire 2 is embedded in the resin coating 3 is sequentially and continuously formed. According to the molding method of this embodiment, a double-headed guidewire 1 having a pair of tip portions 5A and 5B can be molded efficiently and at low cost.

Next, a guidewire 1 according to another embodiment of the present invention will be described with reference to FIG. That is, in a device having a pair of tip portions 5A and 5B as in FIG. 1, the tip portions 5A and 5B have a cross-sectional shape other than a circle such as an ellipse or an oval, and the center line 19 in the long side direction is formed. It has a one-way bending point that is easy to bend only in the X-axis direction, which is a neutral plane, and has an appropriate bending rigidity in directions other than the X-axis direction. In the embodiment shown in FIG.
The pre-shape processing of 5B becomes easier, and the shape quality of the "curved portion 8" is stabilized, so that it is easy to insert the blood vessel and adjust the directions of the distal end portions 5A and 5B in the blood vessel.

The guide wire 1 according to the present invention is not limited to the above-described embodiment. As shown in FIG. 4C, the distal portions 5A and 5B may be tapered or the distal portions 5A and 5B may be tapered. May be formed in a substantially rectangular shape, a polygonal shape, or the like to have a deformed shape having a bending point only in one axial direction, or the wire fixing portion 15 may be formed by other fixing means.

[0023]

As described above, the medical guidewire according to the present invention enables a highly flexible and highly flexible guidewire to be inserted into a blood vessel more smoothly by making the distal end portion thereof more suitable. The performance improvement and efficiency of the preparation work of the vascular treatment by the use of the catheter is promoted, and the therapeutic property is improved. The merits of the configuration can be enjoyed, and the guide wire performance can be further improved. The method for forming a guide wire according to the present invention can efficiently form the useful guide wire and provide it at low cost. There are the above effects.

[Brief description of the drawings]

1A and 1B show a medical guidewire according to a first embodiment of the present invention, wherein FIG. 1A is a front view thereof, FIG. 1B is an EE sectional view of FIG. 1A, FIG. (D) is G in (A)
G section view

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

FIG. 3 is an explanatory view of a method for forming a medical guidewire of the first embodiment.

FIG. 4 shows a medical guidewire according to another embodiment of the present invention, wherein (A) and (B) are cross-sectional views of the distal end portion, and (C).
Is the front view of the tip

FIG. 5 is a partial front view of a conventional medical guidewire.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Medical guide wire 2 Core wire 3 Resin coating 4 Small diameter part 5 ・ 5A ・ 5B Guide wire tip part 6 Guide wire main part 8 V-shaped bent part 10 Chain core wire 11 Guide wire continuous body 13 Twisted wire 14 Element wire 15 Wire fixing part 16 Connector 17 Molding die

Claims (4)

[Claims] 1. A guide wire tip portion of a guide wire, which is a long ultra-fine wire, and a resin wire is applied to a core wire whose end portion has a slightly small diameter portion, and the portion having the small diameter portion is inserted into a blood vessel. In the medical guidewire, the distal end of the guidewire has a diameter smaller than that of the main part of the guidewire other than the distal end of the guidewire, and a pair of medical guides is provided at both ends of the wire. Wire. 2. The medical guidewire according to claim 1, wherein a pair of guide wire tips at both ends are formed of a combination of a large diameter portion and a small diameter portion having a small difference in diameter. 3. The medical guidewire according to claim 1, wherein the core wire is formed of a stranded wire, and a wire fixing portion is provided at a tip end of the narrow diameter portion, where the wires of the stranded wire are fixed to each other. 4. The method of forming a medical guidewire according to claim 1 or 2, wherein the connecting wire is used to connect in series the core wires, each having a slightly longer diameter at both ends of the required diameter wire material, into a small diameter portion. Forming and passing the chain core wire through a forming die of a resin extrusion molding device to form a continuous guide wire body that has been continuously coated with a resin coating for embedding the chain core wire, and the passing speed of the core wire of the forming die or By controlling the resin extrusion amount of the molding die, the narrow diameter portion is embedded, and the tip portion of the guide wire having a reduced outer diameter is automatically molded, and thereafter, the medical guide is cut by dividing the guide wire continuous body. A method for forming a medical guidewire, comprising forming a wire sequentially and continuously.