JPH07148267A - Guide wire for medical treatment and its production - Google Patents

Abstract

PURPOSE:To exactly transmit the rotating operation at the base end of a guide wire to the front end of this guide wire. CONSTITUTION:A wire 11 consisting of an elastic material for springs, more preferably steel wire, is mechanically straightened by leveling rollers 14 and is further passed through a heater 15 where the wire is hot straightened, by which the wire of 1800mm length wound to a loop of 200mm diameter is held for 72 hours. A core wire having a distance of <=10mm apart from the straight part when one end of such wire is clamped and hung and having straightness is produced. The front end of such core wire is formed fine according to need and a coil is fixed to at least the outer periphery at the front end of the core wire, by which the guide wire is obtd.

Description

Detailed Description of the Invention

[0001]

The present invention relates to, for example, blood vessels, ureters,
The present invention relates to a medical guide wire used for inserting a catheter into the trachea or the like, or inserting an indwelling device inside a blood vessel aneurysm, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, for example, in a cardiac catheter test, a technique has been widely adopted in which a catheter is percutaneously inserted without incising the blood vessel and a drug such as a contrast agent is administered to the blood vessel. It was

The procedure of percutaneously inserting a catheter will be described with reference to the drawing of FIG. 7 by taking an arterial puncture as an example. First, the artery 2 is punctured by the puncture needle 1 (a), and then the puncture needle 1 is punctured. Insert the guide wire 3 and
Is left in the artery 2 and the puncture needle 1 is pulled out (b).

Next, a dilator 4 is attached to the outer circumference of the guide wire 3, and the distal end of the dilator 4 is slid along the guide wire 3 and pushed into the artery 2 (c). Thus, when the expansion is completed, the expander 4 is removed (d),
After that, the catheter 5 is slid along the guide wire 3 (e), and the catheter 5 is inserted into the artery 2 (f).

When the catheter 5 is inserted to a predetermined position in the artery 2, the guide wire 3 is pulled out, and then a medical fluid such as a contrast agent is administered to the artery 2 via the catheter 5.

As described above, when the catheter 5 is inserted, the guide wire 3 for guiding the catheter 5 is used. The catheter 5 is used for the blood vessel inspection as described above.
It is used not only for treatment but also for examination and treatment of all tubular organs of the human body such as the ureter and trachea.

As a guide wire as described above, Japanese Unexamined Patent Publication (Kokai) No. 61-106173 discloses a tip portion 42 of a core wire 42 made of a shape memory alloy (TiNi alloy) as shown in FIG.
A guide wire 41 is proposed in which a is thin and the outer periphery is covered with a synthetic resin film 43. The guide wire 41 is characterized in that it has flexibility due to the superelasticity of the shape memory alloy, and that the tip end of the core wire 42 is thin and the tip end is more flexible.

As the guide wire, there is also known a so-called coil guide wire in which a coil is attached to the outer circumference of a core wire having a thin tip.

[0009]

When inserting a guide wire into a blood vessel or a trachea, since these are branched at some places, it is necessary to guide the tip of the guide wire into the target tube at the branch point. For this reason, when inserting the guide wire, the distal end of the guide wire is appropriately bent on the spot according to the patient.

That is, when the tip of the guide wire 41 is wound around the cored bar 44 as shown in FIG. 9, the tip can be bent into an arc shape as shown in FIG. In this way, the guide wire 41 can be easily inserted by stiffening the shape of the tip.

FIG. 11 shows a state in which a guide wire is guided to a blood vessel. Here, the blood vessel 45 into which the guide wire 41 is inserted has its distal end branched into branch pipes 46 and 47, and the distal end of the branch pipe 47 further branches into branch pipes 48 and 49. Then, when the target inspection or treatment site is in the branch tube 49, the distal end of the guide wire 41 is bent as shown in the figure to guide the guide wire 4 along the arrow in the figure.
The tip of 1 can be moved and easily guided to the target branch pipe 49.

However, when the core wire is formed of a shape memory alloy as described above, even if the tip end portion is made thin and has flexibility, it does not plastically deform due to the superelasticity of the shape memory alloy, and the tip end portion has a desired shape. I couldn't squeeze it in the direction.

Further, when guiding the guide wire as shown in FIG. 11, in order to direct the distal end of the guide wire 41 in a desired direction, the operation is performed while rotating the proximal end portion of the guide wire. At this time, it is desired that the rotation operation at the proximal end portion of the guide wire is accurately transmitted to the distal end portion of the guide wire, that is, the rotation transmissibility is good.

However, in the conventional guide wire, the distal end portion does not rotate depending on the rotation angle of the proximal end portion, and the distal end portion tends to rapidly rotate when the proximal end portion is rotated to a certain angle. For this reason, the operation of inserting the guide wire is difficult, which causes a long time.

Accordingly, an object of the present invention is to provide a medical guide wire having good rotation transmissibility and a method for manufacturing the same.

[0016]

DISCLOSURE OF THE INVENTION As a result of intensive studies for achieving the above object, the present inventors have found that the rotation transmissibility of the guide wire is greatly affected by the linearity of the core wire of the guide wire. Since the wire is usually inserted and stored in a spirally wound tube, it was found that even if the initial linearity is good, the linearity is impaired after being stored in the tube, and the present invention is based on these facts. It came to completion.

That is, the medical guide wire of the present invention is a medical guide wire having a core wire made of an elastic material for springs and a coil fixed to at least the outer periphery of the tip end portion of the core wire, wherein the core wire is Characterized by having a straightness of 1800 mm in length wound in a loop of 200 mm in diameter, held for 72 hours, and held at one end thereof and hung to hang it, and the farthest distance from the straight portion is 10 mm or less. And

Further, in the method for manufacturing a medical guide wire according to the present invention, the wire made of the elastic material for spring is mechanically drawn and then heat-treated to obtain a length of 1800.
a loop having a diameter of 200 mm and holding it for 72 hours, and forming a core wire having a straightness with a distance of 10 mm or less with respect to the straight line portion when gripping and suspending one end of the loop, It is characterized in that a coil is fixed to at least the outer circumference of the tip of the core wire.

The present invention will be described in more detail below. The medical guide wire of the present invention has basically the same structure as a conventional guide wire, and is constructed by fixing a coil to at least the outer circumference of the distal end portion of the core wire. However, the present invention is different in that a core wire made of an elastic material for spring and having excellent linearity is used as the core wire.

That is, as the core wire of the guide wire of the present invention, a wire made of an elastic material for springs such as stainless steel, carbon steel and shape memory alloy is used. Particularly, a steel wire for spring such as stainless steel and carbon steel is used. It is preferable.
These wires are linearly processed by the method described later.

Conventionally, as a straight line processing, as shown in FIG. 2, a plurality of straightening rollers 14 are arranged between a feeding roller 12 and a winding roller 13, and a zigzag pattern is formed between the straightening rollers 14 while pulling the wire rod 11. There is known a straight-line processing in which a sheet is passed through and then mechanically straightened to form a straight line.

Further, as shown in FIG. 3, a heating device 15 is provided between the feeding roller 12 and the take-up roller 13, and a linear heating process is also known in which the wire 11 is pulled and passed through the heating device 15 for heat treatment. ing.

However, with such a linear machining alone,
It has been found that a core wire that can achieve the object of the present invention cannot be obtained.

That is, FIG. 12 shows a case for storing the guide wire, but the guide wire 51 is
A spirally wound tube 52 with a diameter of about 20 cm
Has been inserted and saved in. The wire rod that has been subjected to the straight line processing can obtain a sufficient straightness immediately after the processing, but if it is stored in the tube 52 as described above, it will be settled and curved, resulting in a linearity. Will be damaged.

Further, the wire which has been subjected to the heat straightening process is unlikely to cause the fatigue even if it is stored in the tube 52 as described above, but a sufficient straightness to the extent that the object of the present invention can be achieved is obtained. I can't.

Therefore, in the present invention, as shown in FIG. 1, a plurality of straightening rollers 14 and a heating device 15 are arranged between the feeding roller 12 and the winding roller 13.
A method is adopted in which the wire rod 11 drawn out from the feed roller 12 is passed through a straightening roller 14 to be mechanically drawn, and then passed through a heating device 15 for heat treatment.

As a result, it is possible to obtain a core wire which has good linearity and which is not impaired in linearity when inserted into a spirally wound tube and stored.

In the present invention, the straightness of the core wire means a value measured by the following method. That is, as shown in FIG. 4, the length A of the core wire 21 is set to 1800 mm, and the core wire 21 is wound around a loop having a diameter of 200 mm to be 7 mm.
The length B, which is the farthest from the straight line portion when held for 2 hours and held by the holder 22 and hung down, was obtained, and the straightness degree was expressed by this distance B.

As the core wire of the guide wire of the present invention, one having the above linearity of 10 mm or less, preferably 5 mm or less is used. When the linearity exceeds 10 mm, the rotation transmission property deteriorates, and a guide wire with good operability cannot be obtained.

The rotation transmissibility of the obtained core wire was evaluated by the method shown in FIG. That is, length 1
Insert the core wire 21 made to 800 mm into a catheter 53 wound once in a loop having a diameter of 200 mm, connect a rotary encoder 54 to the distal end portion of the core wire 21, and gradually rotate the proximal end portion of the core wire 21. The rotation angle of the tip part with respect to the rotation angle of the base part was measured.

In the present invention, the core wire is preferably a steel wire for spring such as stainless steel or carbon steel,
A shape memory alloy wire can be used, but is not so preferable for the following reasons.

In order to store the superelastic material in a straight line, the superelastic material is heated to the storage temperature while being mechanically held in a straight line state. However, in the tension annealing method which is usually carried out, the straightness is excellent because the heating time is short. Getting things is difficult.

The memory mechanism of the shape memory alloy is that crystals are rearranged so as to cancel the internal strain in the alloy during heating, and the memory is memorized. Even if straightness is provided by machining in advance. Since the effect is lost by the heat treatment, the initial straightness cannot be obtained.

In order to obtain excellent straightness only by heat treatment, the residual strain during wire drawing must be reduced to 0. As this treatment, the temperature is raised to the recrystallization temperature range of the shape memory alloy and then quenched. Then, the aging treatment is performed to further improve the slip limit value, but at this time, the wire must be kept in a linear state by applying some force, resulting in an extremely high manufacturing cost.

In order to better exert the superelastic effect, in the case of the methods other than the above, it is necessary to leave as much processing strain as possible during wire drawing, but for this purpose, it is necessary to carry out heat treatment at a low temperature for a short time. Therefore, it is necessary to make the working rate uniform during wire drawing, and it is difficult to satisfy this.

In the guide wire of the present invention, the core wire preferably has a thickness of about 0.15 to 0.7 mm and a length of 50.
About 0 to 3000 mm is preferable. The tip of the core wire is preferably made thin, for example, in a tapered shape in order to give flexibility. The length of the reduced diameter portion (the length of 42a in FIG. 8) is preferably 50 to 400 mm.

Then, the guide wire of the present invention can be manufactured by fixing the coil to at least the outer periphery of the distal end portion of the core wire.

In this method, it is preferable that the tip end portion of the core wire is formed thin, for example, in a tapered shape, and a coil having substantially the same diameter as the base portion of the core wire is brazed to the outer circumference of the tip end portion of the core wire. A round head is preferably formed at the tip of the coil so as not to damage the tissue inside the body. Further, it is preferable that the coil is formed of X-ray opaque gold or platinum or a wire rod plated with gold or platinum.

[0039]

Since the guide wire of the present invention uses the core wire having the above-described linearity, excellent rotation transmissibility can be obtained as shown in a test example described later. As a result, when the human body is inserted into the tubular organ, the rotation operation at the proximal end of the guide wire is accurately transmitted to the distal end of the guide wire,
The insertion operation can be facilitated and the work time can be shortened.

Further, the guide wire is usually inserted into the spirally wound tube 52 shown in FIG. 12 for transportation and storage. The degree is not lost.

Furthermore, in the guide wire of the present invention, when the core wire is made of a steel wire for spring, the tip portion is easily bent and bent, and the shape of the tip portion can be changed according to the shape of the tubular organ. The operation becomes easier.

On the other hand, according to the method of manufacturing the guide wire of the present invention, the core wire having the above-described straightness can be easily manufactured by combining the mechanical linear drawing and the thermal linear processing. .

[0043]

【Example】

Example A stainless wire having a diameter of 0.4 mm was mechanically drawn and heat-wired by the method shown in FIG.
The heat treatment was performed at 400 ° C. for 30 minutes. This wire rod was cut into a length of 1800 mm to obtain a core wire.

The core wire obtained in this manner was prepared as shown in FIG.
When the length of B was determined by the method shown in, it was 2 mm.
Furthermore, wind this core wire in a loop with a diameter of 200 mm and
After holding for a time, the length of B was determined by the method shown in FIG. 4 and was 5 mm.

As shown in FIG. 13, the tip portion 62a of the core wire 62 is formed in a tapered shape with a predetermined length. A coil 64 made by plating the surface of a tungsten coil with gold is attached to the outer periphery of the tip portion 62a, the base portion of the coil 64 is fixed to the core wire 62 with a brazing material 65, and the tips of the coil 64 and the core wire 62 are brazed material 66. And a round head 63 was formed.

The guide wire thus obtained is shown in FIG.
Even after being stored in the spiral-wound tube shown in (3), it had an excellent rotation transmission property, and it was easy to bend and bend the tip.

Comparative Example 1 A stainless wire having a diameter of 0.4 mm was mechanically drawn by the method shown in FIG. Length of this wire is 180
A core wire was obtained by cutting into 0 mm.

The core wire thus obtained is shown in FIG.
When the length of B was determined by the method shown in, it was 1 mm.
Furthermore, wind this core wire in a loop with a diameter of 200 mm and
After holding for a period of time, the length of B was determined by the method shown in FIG. 4 and was found to be 35 mm.

Comparative Example 2 A stainless wire having a diameter of 0.4 mm was heat-linearly processed at 600 ° C. for 15 seconds by the method shown in FIG. This wire rod was cut into a length of 1800 mm to obtain a core wire.

The core wire thus obtained is shown in FIG.
When the length of B was determined by the method shown in, it was 70 mm. Further, this core wire was wound around a loop having a diameter of 200 mm and held for 72 hours, and then the length of B was determined by the method shown in FIG.

Test Example A stainless wire having a diameter of 0.4 mm was mechanically drawn and heat-wired by the method shown in FIG.
However, eight kinds of wire rods were produced by changing the heat treatment conditions. A core wire was obtained by cutting these wires to a length of 1800 mm.

The core wire thus obtained has a diameter of 20
After wrapping it in a 0 mm loop and holding it for 72 hours, the length of B was determined by the method shown in FIG.
m, 6 mm, 7 mm, 10 mm, 13 mm,
There were eight types, 18 mm and 35 mm.

FIG. 6 shows the results of measuring the rotation transmissibility of these core wires by the method shown in FIG. In addition, ~ in FIG. 6 corresponds to the above ~.

Thus, it can be seen that the higher the linearity of the core wire, the higher the tendency of the distal end side to rotate in proportion to the rotation angle of the core wire on the base side, and the better the operability of the guide wire.

[0055]

As described above, according to the guide wire of the present invention, since the core wire has a specific straightness, it has excellent rotation transmissibility. As a result, a guide wire with good operability can be provided.

Further, when the core wire is made of spring steel wire, it becomes easy to bend and bend the tip end according to the application site.

Further, according to the method of manufacturing the guide wire of the present invention, the core wire having the above-mentioned linearity can be easily manufactured by combining the mechanical linear drawing and the thermal linear processing. .

[Brief description of drawings]

FIG. 1 is an explanatory view showing an example of a method of manufacturing a core wire used for a guide wire of the present invention.

FIG. 2 is an explanatory diagram showing a mechanical linear drawing method.

FIG. 3 is an explanatory diagram showing a hot linear processing direction.

FIG. 4 is an explanatory diagram showing a method for measuring the linearity of a core wire according to the present invention.

FIG. 5 is an explanatory diagram showing a method of measuring rotation transmissibility.

FIG. 6 is a chart showing the results of measuring the rotational transmissibility of various core wires.

FIG. 7 is an explanatory diagram showing a general catheter insertion method.

FIG. 8 is a cross-sectional view showing an example of a conventional guide wire.

FIG. 9 is an explanatory diagram showing a method of curving the tip of the guide wire.

FIG. 10 is an explanatory view showing a state where the tip of the guide wire is bent and bent.

FIG. 11 is an explanatory diagram showing an example of guiding a guide wire into a blood vessel.

FIG. 12 is a plan view showing a tube for storing a guide wire.

FIG. 13 is a partial cross-sectional view showing one embodiment of the guide wire of the present invention.

[Explanation of symbols]

 11 wire rod 12 delivery roller 13 winding roller 14 straightening roller 15 heating device 21 core wire 53 catheter 54 rotary encoder 61 guide wire 62 core wire 63 head 64 coil 65, 66 brazing material

Claims (4)

[Claims] 1. A medical guide wire comprising a core wire made of an elastic material for a spring and a coil fixed to at least the outer circumference of the tip of the core wire, wherein the core wire has a length of 18 mm.
Wrap a piece of 00 mm in a loop of diameter 200 mm to 72
A medical guide wire, which has a linearity in which a distance most distant from a linear portion when held for one hour and grasped at one end and hung is 10 mm or less. 2. The core wire is made of a wire made of stainless steel or carbon steel and having a diameter of 0.15 to 0.7 mm.
The medical guide wire described. 3. A wire rod made of an elastic material for a spring is mechanically drawn and then heat-treated to obtain a length 1
Wrap an 800 mm loop around a 200 mm diameter loop. 7
Hold a wire for 2 hours, form a core wire having a linearity with a distance of 10 mm or less from the straight part when grasping and suspending one end of the core wire, and fix the coil to at least the outer circumference of the tip part of the core wire. A method for manufacturing a medical guide wire, comprising: 4. The method for manufacturing a medical guide wire according to claim 3, wherein a wire made of stainless steel or carbon steel and having a diameter of 0.15 to 0.7 mm is used as the wire.