JPH08173547A - Guide wire for medical care - Google Patents

Abstract

PURPOSE: To provide a guide wire of which a tip position can be accurately confirmed through radiation transillumination in the case of insertion into a tubular organ, of which a tip has uniform flexibility as a whole, and in which a bendable part due to stress concentration is not formed. CONSTITUTION: A tip 12a of a core wire 12 is formed gradually thinner and an exterior coil 13 is arranged in an outer periphery of the tip 12a. A base end of the exterior coil 13 is fixed to the core wire 12, and a tip thereof together with a tip of the core wire 12 is fixed to a head 15. An interior coil 14 made of a radiation untransmissive material is arranged inside the exterior coil 13, and in the interior coil 14, a tip thereof is fixed to the head 15, or a base end thereof together with an intermediate part of the exterior coil 13 is fixed to the core wire 12 to make the other end free. It is desirable that a coil pitch is enlarged or coil initial tension is eliminated in at least the tip of the exterior coil 13 and/or the interior coil 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical guide wire used for inserting a catheter into a blood vessel, ureter, bile duct, trachea or the like.

[0002]

2. Description of the Related Art In recent years, in order to inspect and treat tubular organs of the human body such as blood vessels, ureters, bile ducts, and trachea, a catheter is inserted to administer a drug solution such as a contrast agent, or tissue is passed through the catheter to force tissue Some of them are collected. When inserting a catheter, a relatively thin and flexible guide wire is first inserted into the tubular organ, the catheter is inserted along the outer circumference of the guide wire, and then the guide wire is pulled out.

Since the guide wire is to be inserted into a tubular organ such as a blood vessel, it has a flexible tip so that damage to the tissue during insertion can be reduced, and the base side is rotated at the branch point of the tubular organ. When it is turned on, the tip side rotates following it so that the tubular organ to be advanced can be selected, so that it has excellent torque transmission and the tip position can be confirmed by fluoroscopy such as X-ray. It needs to be

Conventionally, as the above guide wire,
For example, Japanese Examined Patent Publication No. 4-25024 and Japanese Patent Laid-Open No. 6-17
The guide wires disclosed in JP-A-8811 and JP-A-63-181774 are known.

FIG. 3 shows a guide wire disclosed in Japanese Patent Publication No. 4-25024. The guide wire 31 is formed such that a tip portion 32a of a metal core wire 32 is gradually thinned, two coils 33 and 34 are attached to the outer circumference of the tip portion 32a, and the ends of the coil 34 and the core wire 32 are rounded. It has a structure fixed to 35.

The coil 33 is arranged on the base side of the tip end portion 32a of the core wire 32, and the base portion is fixed to the core wire 32 with a brazing metal 36. The coil 34 is arranged on the tip side of the tip portion 32a of the core wire 32, and the tip is fixed to the round head portion 35 as described above. The tip of the coil 33 and the base of the coil 34 are screwed into each other between the respective pitches, and are fixed to the core wire 32 with a metal brazing 37. The coil 34 on the tip side is formed of a radiopaque material.

FIG. 4 shows a guide wire disclosed in JP-A-6-178811. In this guide wire 41, the distal end of the core wire 42 is
The reduced diameter portion 42b, the tapered portion 42c, the reduced diameter portion 42d, the tapered portion 42e, and the reduced diameter portion 42f are formed so as to become thinner in this order, and the coil 43 is arranged on the outer periphery of the tip end portion thereof. The base end of the coil 43 has a tapered portion 42 of the core wire 42.
It is fixed to a by a brazing material, and the tip of the coil 43 has a core wire 4
Rounded head 44 fixed to the tip of 2 with brazing material
Is doing. And the most reduced diameter portion 42 of the core wire 42
A ring member 45 made of a radiopaque material is attached to the outer periphery of f and inside the coil 43 so as to be movable in the length direction of the core wire 42.

Further, in Japanese Unexamined Patent Publication No. 6-178811, as another embodiment of the guide wire 41 shown in FIG. 4, a ring member 45 is provided at the most tip end reduced diameter portion 42 of the core wire 42.
It is also disclosed that it is fixed slightly to the base side from the middle of f.

FIG. 5 shows a guide wire disclosed in Japanese Patent Laid-Open No. 63-181774. The guide wire 51 is formed such that a tip portion 52a of a core wire 52 is tapered and thin, and an outer coil 53 is attached to the outer circumference of the tip portion 52a. The outer coil 53 has its base end fixed to the core wire 52, and its tip extends further ahead of the tip of the core wire 52 and is fixed to the head portion 54. An inner coil 55 having a smaller diameter than that of the inner coil 55 is arranged inside the coil 53. A proximal end of the inner coil 55 is fixed to a tip of the core wire 52, and a tip of the inner coil 55 is fixed to a head 54. Although the inner coil 55 acts as a safety wire, it is stated that it may be made of a radiopaque material.

[0010]

However, in the guide wire 31 disclosed in Japanese Patent Publication No. 4-25024 shown in FIG. 3, the connecting portions of the two types of coils 33 and 34 are relatively long, and brazing is performed. Since it increases rigidity, when inserting into a relatively thin and curved part such as a blood vessel,
There was a problem that the part was difficult to bend and could not be inserted, or the part adjacent to the brazing part was likely to be bent (kink).

Further, Japanese Patent Laid-Open No. 6-17881 shown in FIG.
The guide wire 41 disclosed in Japanese Unexamined Patent Publication No. 1 has a problem that the manufacturing cost is high because the productivity of the ring member 45 is poor, and the ring member 45 can be moved by the most reduced diameter portion 42f of the core wire 42. When the ring member 45 is fixed to the tip end reduced diameter portion 42f of the core wire 42, there is a problem that the tip position of the guide wire 41 cannot be accurately grasped due to the movement of the ring member 45. However, there is a problem that stress is likely to be concentrated at the boundary portion and bending is likely to occur at that portion.

Furthermore, Japanese Patent Laid-Open No. 63-1817 shown in FIG.
In the guide wire 51 disclosed in Japanese Patent Publication No. 74, when the outer coil 53 is caught somewhere and is to be pulled out, the inner coil 55 may expand together with the outer coil 53. Core wire 5
Since it is fixed to the second tip portion 52a, stress concentration occurs at that portion, and there is a problem that bending is likely to occur.

The present invention has been made in view of the above problems, and an object thereof is to be able to accurately confirm the distal end position by radioscopy when inserting it into a tubular organ, and An object of the present invention is to provide a guide wire that has uniform flexibility as a whole and in which stress is not concentrated and a portion that is easily bent is not formed.

[0014]

In order to achieve the above object, the first guide wire of the present invention has a core wire formed so that the distal end portion becomes thinner, and a roundness formed at the distal end of the core wire. A guide wire having a head portion and an outer coil having a distal end fixed to the head portion and a proximal end fixed to a portion of the core wire where the core wire starts to be thin, and a radiation wire is provided inside the outer coil. An inner coil, which is made of a permeable material and is shorter than the outer coil, is arranged, and the inner coil has a distal end fixed to the head and a proximal end free.

In the second guide wire of the present invention, the core wire is formed such that the distal end portion is gradually thinned, the rounded head is formed at the distal end of the core wire, and the distal end is attached to the head portion. A guide wire, comprising: an outer coil having a proximal end fixed to a portion of the core wire where the core wire starts to thin, the outer coil having an intermediate portion thereof fixed to the core wire. An inner coil made of a radiopaque material and shorter than the outer coil is disposed inside the inner coil, the inner coil having a proximal end fixed to the core wire together with a middle portion of the outer coil, and a distal end free. It is characterized as being.

[0016] In the present invention, it is preferable that at least a tip portion of the outer coil is removed from initial tension of the coil, or a coil pitch is opened. Similarly, it is preferable that the inner coil is also removed from the initial tension of the coil or the coil pitch is opened.

Further, in the first guide wire of the present invention, it is preferable that an intermediate portion of the outer coil is fixed to the core wire at a side closer to a base portion than a free base end of the inner coil.

[0018]

In the present invention, the inner coil made of a radiopaque material is arranged inside the outer coil, and the inner coil is
The distal end is fixed to the head part, or the proximal end is fixed to the core wire together with the intermediate part of the outer coil, so that the inner coil does not move in the axial direction when inserted into the tubular organ, It is possible to accurately confirm the position of the tip of the guide wire by fluoroscopy. Moreover, since the coil is doubled at the distal end portion of the guide wire, the contrast property is further improved.

Further, the inner coil has its tip fixed to the head portion, or its base end is fixed to the core wire together with the intermediate portion of the outer coil, and the other end is free, so that the tip of the guide wire is free. It is not necessary to provide a long brazed portion in the middle of the portion, the flexibility of the distal end portion of the guide wire is not impaired, and a portion where the stress is concentrated and easily bent is not formed.

Further, the outer coil is composed of one continuous coil, the inner coil is fixed at one end and free at the other end, and the radiopaque material such as platinum is rigid. Is weak, so that even if doubled, uniform flexibility can be obtained as a whole without impairing flexibility.

In a preferred embodiment of the invention, at least the tip of the outer coil and / or the inner coil is free from the initial tension of the coil, or when the coil is pitched, the tip is flexible. Sex is improved.

Further, particularly in the above case, if the middle portion of the outer coil is also fixed to the core wire, it is possible to prevent the outer coil from moving in the axial direction and partially closing or opening the pitch.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the guide wire of the present invention. This guide wire 11 has a tip 12
a has a core wire 12 formed in a taper shape or a step shape so as to be gradually thin. An outer coil 13 is arranged on the outer circumference of the tip portion 12a of the core wire 12, and a base end of the outer coil 13 is fixed to a portion of the core wire 12 where the core wire 12 starts to be thin by a brazing material 16. The tip ends of the core wire 12 and the outer coil 13 are fixed to a head portion 15 formed of a brazing material and having a rounded tip side. The head 15
Can also be formed, for example, by melting the tips of the core wire 12 and the outer coil 13.

Further, in this embodiment, the brazing material 18 is provided in the middle portion of the outer coil 13 in the middle of the tip portion 12a of the core wire 12.
Is stuck by. The brazing material 18 prevents the outer coil 13 from moving in the axial direction, and since the amount of adhesion is relatively small and spot-like connection is sufficient, the flexibility of the distal end portion of the guide wire 11 is not impaired. However, particularly when the outer coil 13 is closely wound, the brazing material 18 does not have to fix the intermediate portion.

Inside the outer coil 13, the outer coil 1
An inner coil 14 made of a radiopaque material having an outer diameter smaller than the inner diameter of 3 and shorter than the outer coil 13 is arranged. The tip of the inner coil 14 is fixed to the head 15 together with the tip of the core wire 12 and the tip of the outer coil 13, and the base end of the inner coil 14 is the outer coil 13.
The brazing material 18 has a length that does not reach the middle portion fixed to the core wire 12, and is free from being fixed to the core wire 12.

The core wire 12 is preferably made of an elastic metal material such as stainless steel, shape memory alloy, or piano wire. Further, the core wire 12 is not limited to one wire and may be a twisted wire in which a plurality of thin wires are twisted together. The diameter on the base side of the core wire 12 is 0.2
~ 0.8 mm is preferable, the total length is 300 ~ 3000 mm
The length of the tip portion 12a is preferably about 60 to 450 mm.

As the outer coil 13, like the core wire 12, an elastic metal material such as stainless steel, a shape memory alloy, or a piano wire is preferably used. The outer diameter of the outer coil 13 is
It is preferably about 0.15 to 0.36 mm, and the wire diameter is preferably about 20 to 200 μm. Further, it is preferable that the outer coil 13 has a length substantially equal to that of the tip portion 12a of the core wire 12.

For the inner coil 14, it is necessary to use a radiopaque material. Examples of the radiopaque material include gold, platinum, tantalum, tungsten, iridium, rhenium, and alloys thereof, but gold, platinum, and alloys thereof are particularly preferably used. The outer diameter of the inner coil 14 is preferably about 0.1 to 0.35 mm, the length is preferably about 1 to 50 mm, and the wire diameter is 10 to
About 30 μm is preferable.

The core wire 12, the outer coil 13, the head 1
The outer periphery of 5 or the like may be coated with a synthetic resin film such as a fluororesin or a synthetic resin tube, if necessary, and the surface of the synthetic resin film may be coated with a hydrophilic polymer. Examples of such a hydrophilic polymer include resins disclosed in Japanese Patent Publication No. 14991/1991.

According to this guide wire 11, since the inner coil 14 made of a radiopaque material is provided inside the outer coil 13, the radiopacity of the inner coil 14 and the resistance of the inner coil 14 to the radiopaque material. Combined with the opacity of the heavy coil, the position of the tip of the guide wire 11 can be easily confirmed by fluoroscopy. Also, the inner coil 14
Since its tip is fixed to the head portion 15, it does not move in the axial direction, and accurate position confirmation is possible.

The middle portion of the outer coil 13 is the brazing material 1.
It is fixed in the middle of the tip portion 12a of the core wire 12 by 8, but that portion may be connected in spots, and the base end of the inner coil 14 is free without being fixed to the core wire 12. Therefore, the flexibility of the distal end portion of the guide wire 11 is not impaired, and bending stress is prevented from being concentrated and broken.

FIG. 2 shows another embodiment of the present invention. Note that the substantially same parts as those in the embodiment of FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

The guide wire 21 includes an outer coil 23.
From the base end fixed to the core wire 12 with the brazing filler metal 16 of the brazing filler metal 1
The base end portion 23a up to the intermediate portion fixed to the core wire 12 at 8 is closely wound, and the tip end portion 23b from the intermediate portion to the tip fixed to the head portion 15 has a coil pitch. As a result, the flexibility of the portion where the inner coil 14 is arranged to form the double coil is maintained. In this case, the outer coil 23 has a brazing filler metal 18 at the middle portion.
Since it is fixed to the core wire 12 with each other, each coil of the outer coil 23 is prevented from moving in the axial direction and the position where the coil pitch is opened is displaced. The coil gap at the tip portion 23b of the outer coil 23 is 1/3 to 2 of the coil wire diameter.
It is preferable to open about / 3. The same effect can be obtained by removing the initial tension of the tip portion 23b of the outer coil 23. Further, the inner coil 14 may also have the coil pitch opened or the initial tension removed.

FIG. 6 shows still another embodiment of the present invention. Note that the substantially same parts as those in the embodiment of FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted.

In this guide wire 61, the intermediate portion of the outer coil 23 is attached to the core wire 12 and the brazing material 18 as in the above embodiment.
And the base end portion 23a from the base end of the outer coil 23 to the intermediate portion is closely wound, and the intermediate portion to the head portion 1
The coil pitch is opened in the tip portion 23b up to the tip fixed to 5. Further, in this embodiment, the inner coil 64 made of a radiopaque material also has a coil pitch. Also, the inner coil 64
Has its base end fixed to the core wire 12 with a brazing material 18 together with the intermediate portion of the outer coil, and its tip end is free.

In this embodiment, the coil pitch is widened in both the tip portion 23b of the outer coil 23 and the inner coil 64, so that the tip portion is more flexible. The inner coil 64 has its base end fixed to the core wire 12 by the brazing material 18 at the intermediate portion of the outer coil 23, and the brazing width w thereof is preferably 1 mm.
By the following, the flexibility of the distal end portion of the guide wire is not impaired, and it is possible to prevent the formation of a portion that is likely to bend due to stress concentration.

[0037]

As described above, according to the guide wire of the present invention, the outer coil and the inner coil are provided at the tip of the core wire, the inner coil is made of a radiopaque material, and the inner coil has its tip or Since it has a structure in which only the proximal end is fixed, the distal end position of the guide wire can be easily and accurately confirmed by fluoroscopy. Further, since the outer coil is composed of one continuous coil and one end of the inner coil is free, the flexibility of the distal end of the guide wire is sufficiently maintained. Further, since it is not necessary to provide a long brazing part in the middle of the guide wire tip, the brazing part may impair the flexibility of the guide wire tip, or bending stress may be concentrated and easily broken. Is prevented.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a guide wire of the present invention.

FIG. 2 is a sectional view showing another embodiment of the guide wire of the present invention.

FIG. 3 is a sectional view of an essential part showing an example of a conventional guide wire.

FIG. 4 is a cross-sectional view showing another example of a conventional guide wire.

FIG. 5 is a sectional view showing still another example of a conventional guide wire.

FIG. 6 is a cross-sectional view showing still another example of the guide wire of the present invention.

[Explanation of symbols]

 11, 21, 61 Guide wire 12 Core wire 12a Core wire tip portion 13, 23 Outer coil 23a Outer coil base end portion 23b Outer coil tip portion 14, 64 Inner coil 15 head portion

Claims (7)

[Claims] 1. A core wire having a tip portion that is gradually thinned, a rounded head portion formed at the tip end of the core wire, a tip portion that is fixed to the head portion, and the core wire is thinned. In a guide wire comprising an outer coil having a proximal end fixed to a starting portion, an inner coil made of a radiopaque material and shorter than the outer coil is arranged inside the outer coil. Is a medical guide wire having a distal end fixed to the head and a proximal end free. 2. The at least tip portion of the outer coil is
The medical guide wire according to claim 1, wherein the initial tension of the coil is removed or the coil pitch is opened. 3. The medical guide wire according to claim 1, wherein the inner coil is formed by removing the initial tension of the coil or the pitch of the coil is opened. 4. The medical device according to claim 1, wherein an intermediate portion of the outer coil is fixed to the core wire on a base side from a free base end of the inner coil. Guide wire. 5. A core wire formed so that its tip portion becomes gradually thinner, a rounded head portion formed at the tip end of this core wire, a tip portion fixed to this head portion, and the core wire becoming thinner. A guide wire comprising an outer coil having a proximal end fixed to a starting portion, wherein the outer coil is
An intermediate part thereof is also fixed to the core wire, and an inner coil made of a radiopaque material and shorter than the outer coil is arranged inside the outer coil, and the inner coil has a proximal end which is the outer coil. A medical guide wire, characterized in that it is fixed to the core wire together with the middle part of the and the tip is free. 6. The at least tip portion of the outer coil is
The medical guide wire according to claim 5, wherein the initial tension of the coil is removed or the coil pitch is opened. 7. The medical guide wire according to claim 5, wherein the inner coil is formed by removing the initial tension of the coil or the pitch of the coil is opened.