JP2007143695A - Pusher wire for living body indwelling member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pusher wire which aligns the axial directional length of a radiopaque coil section or the like of a spring coil at the distal end of the pusher wire with high precision, and in which the spring coil is tightly fastened to a main wire material at a butting portion of the radiopaque coil section and a radiolucent coil section, and flexibility as the pusher wire is kept. <P>SOLUTION: The pusher wire for a living body indwelling member has the flexible main wire material and the spring coil, the spring coil is composed of the radiopaque coil section and the radiolucent coil section, an area from the distal end portion to the proximal end side of the main wire material is inserted into the spring coil, and the radiopaque coil section and the radiolucent coil section of the spring coil and the main wire material are secured by welding. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pusher wire that introduces a required living body indwelling member through a catheter to a required location in the living body.

  In general, there are various problems in the treatment of living bodies accompanied by surgical operations. For example, a patient to be treated must endure a long-time operation, and an operator is forced to concentrate nerves for a long time, and the risk of infection is relatively high. In order to alleviate such various burdens and to perform necessary operations more safely and simply, embolization materials for occluding tubular organs such as catheters, guide wires, blood vessels, etc. Various medical devices have been developed and put into practical use.

  For example, recent advances in medical devices such as catheters and guidewires have led to intravascular surgery approaching the desired affected area from within the blood vessel, especially arteriovenous malformations, cerebral aneurysms, carotid arteries It has been widely applied to the treatment of diseases such as cavernous sinus. At present, detachable balloons, coils, liquid embolic materials, particulate embolic materials, and the like are used as tubular organ embolic materials. However, these embolic materials that are usually placed in tubular organs, etc. are rarely collected or corrected once they are placed or released in an inappropriate position. Impossible.

  Under such circumstances, even if it has failed to arrange at the target location in the past, it can be pulled back and reinserted, and the embolic material can be removed and placed after confirming the location. Possible detachable embolic materials have been proposed.

  For example, in Japanese Patent Laid-Open No. 7-265431, an in-vivo indwelling member is connected to a distal end portion of a conductive pusher wire main body via a connecting member, and a cutting current is supplied via the pusher wire main body. Thus, there has been proposed a medical wire in which the connecting member is heated and thereby the in-vivo indwelling member is removed. The pusher wire referred to here indicates a wire that can be pulled back when a living body indwelling member such as an embolic material is pushed through the catheter and has a joining member.

  Such a detachable embolic material is assumed to be cut with the connecting member slightly protruding from the catheter tip. However, in general, the embolic material is often radiopaque, and as the embolization is performed, the catheter tip is hidden by the embolic material, and it is often difficult to confirm whether the connecting member protrudes from the catheter tip. Therefore, generally used catheters are provided with a second marker at a certain distance from the tip to the proximal side, and the pusher wire aligns the radiopaque coil portion of the spring coil at the tip with the second marker, It is designed so that the connection part appears slightly.

  For the pusher wire of embolization material that is not detachable, the radiopaque coil part of the spring coil at the tip is used as the second marker of the catheter so that the tip of the pusher wire does not jump out of the catheter during use. It is preferable that the connection portion is designed to come out slightly from the catheter tip when combined.

  Therefore, in order to accurately position the pusher wire using the second marker of the catheter, it is necessary to accurately align the axial length of the radiopaque coil portion of the spring coil or the radiolucent coil portion of the pusher wire tip. is there. Therefore, in the pusher wire, it is preferable that the tip of the main wire and the spring coil are fixed, and further, the main wire and the spring coil are fixed at the abutting portion of the radiation opaque coil portion and the radiation transparent coil portion.

Currently, adhesive and brazing are used to fix the main wire of the pusher wire and spring coil that are generally used. However, the adhesive has low tensile strength and is difficult to use due to safety issues. The length of the brazed portion in the axial direction is long, and the flexibility as a pusher wire is easily lost. Also, in the case of brazing, the axial length of the radiopaque part coil part or the radiopaque part coil part to be aligned with the second marker by flowing the radiopaque braze into the gap between the spring coil part and the main wire There is a problem that is not stable.
JP-A-7-265431

  In view of the above problems, the present invention accurately aligns the axial length of the radiopaque coil portion of the spring coil or the radiolucent coil portion of the spring coil at the tip of the pusher wire. It is an object of the present invention to provide a pusher wire in which the spring coil is firmly fixed to the main wire at the mating portion, and the flexibility as the pusher wire is not lost.

Thus, the present invention:
(1)
A flexible main wire,
A spring coil comprising a radiation opaque coil part and a radiation transparent coil part;
One region from the front end portion of the main wire to the rear end side is inserted through the spring coil;
The radiopaque coil portion of the spring coil, the radiolucent coil portion, and the main wire are fixed by fusion welding;
A pusher wire for a living indwelling member comprising:
(2)
The pusher wire for an embolization indwelling member according to (1), wherein an axial length of the fused part is 0.1 mm or more and 1.5 mm or less;
(3)
The method of fusion welding is laser welding, wherein the pusher wire for living body indwelling members according to (1) or (2);
(4)
The pusher wire for a living body indwelling member according to any one of (1) to (3), wherein in the main wire, at least a part of a portion where the spring coil is mounted is a flat wire;
(5)
For the indwelling member according to any one of (1) to (4), wherein the radiopaque coil portion includes at least one selected from the group consisting of platinum, gold, tungsten, tantalum, silver, iridium, palladium, and lead. Pusher wire;
(6)
Any of (1) to (5), wherein the pusher wire is made of a conductive material, and an insulating coating is further provided on the surface of the pusher wire excluding a tip end portion of the spring coil and a rear end portion of the main wire. A pusher wire for a living body indwelling member according to claim 1;
(7)
The pusher wire for a living body indwelling member according to any one of (1) to (6), wherein a distal end portion of the main wire and the spring coil are fixed by fusion welding;
(8)
In the spring coil part, the radiopaque coil part is further provided on the tip side of the radiopaque coil part, and the pusher wire for a living indwelling member according to any one of (1) to (7); (9)
A medical wire, the medical wire
(1) to (8) any one of the pusher wires for indwelling members,
An in-vivo indwelling member connected via a heat-soluble connecting member to the tip of the push-in wire for the indwelling member;
The fusing current is supplied through the pusher wire for the living body indwelling member, so that the connecting member is heated and melted, whereby the indwelling member is removed;
A medical wire comprising:
I will provide a.

According to the present invention (1), the radiation opaque coil portion, the radiation transparent coil portion, and the main wire of the spring coil are fixed by fusion welding, so that the spring coil at the tip of the pusher wire is fixed. The axial length of the radiopaque coil part or the radiopaque coil part is accurately aligned, and the spring coil is firmly fixed to the main wire at the joint part of the radiopaque coil part and the radiopaque coil part. It becomes possible that the flexibility as a wire is not lost.

  According to the present invention (2), the flexibility of the joint portion is further ensured when the axial length of the fused portion is 0.1 mm or more and 1.5 mm or less.

According to the present invention (3), since the welding method is laser welding, it is possible to suppress the heat influence on the weld peripheral portion as much as possible, and the axial length of the fusion weld portion is 1.5 mm or less. Things are provided.
According to the present invention (4), in the main wire, at least a part of the portion where the spring coil is mounted is a flat wire, so that the tip side can be made more flexible.

  According to the present invention (5), the radiopaque coil part further includes at least one selected from the group consisting of platinum, gold, tungsten, and lead, so that radiopaque performance can be obtained. .

According to the present invention (6), the pusher wire main body has conductivity, and the pusher wire main body is insulated and coated except for the front end of the spring coil and the rear end of the main wire. It is possible to efficiently supply a high frequency current.
According to the present invention (7), the distal end portion of the main wire and the spring coil are fixed by fusion welding, so that the radiopaque coil portion of the spring coil, without losing flexibility, or It is possible to align the axial length of the radiation transmitting coil part with high accuracy.

  According to the present invention (8), in the spring coil portion, the radiation transmitting coil portion is disposed on the distal end side of the radiopaque coil portion, so that the spring coil portion is mounted on the distal end side of the pusher wire for the living body indwelling member. Clear imaging of a radiopaque in-vivo indwelling member is possible.

  By supplying a high-frequency current through the flexible main wire with the medical wire as in the present invention (9), the living body is applied to the exposed surface of the flexible main wire forming the heating electrode portion. Joule heat is generated by electrical resistance generated by contact with the body fluid (electrolyte solution), the heat-soluble connecting member is melted, and the in-vivo indwelling member is detached.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view showing an example of the configuration of the pusher wire of the present invention. The pusher wire in this example is basically composed of a flexible main wire 10 and a spring coil 11 provided at the tip of the main wire 10. One region from the front end portion to the rear end side of the main wire is inserted into the spring coil 11. That is, the spring coil 11 covers one region from the front end portion to the rear end side of the main wire 10. For the purpose of delivering the embolization indwelling member, the one region is preferably in the range of 40 to 100 mm from the tip.
Examples of the material of the flexible main wire 10 include metals such as stainless steel, gold, platinum, aluminum, tungsten, tantalum, cobalt, chromium, nickel, titanium, and alloys thereof. Although it does not specifically limit as a form of a main wire, From a viewpoint of making a front end side flexible, it is preferable that the main wire 10 is taper-shaped so that it may become thin toward a front-end | tip part from a terminal part. Since the tip portion is thin, the spring coil 11 can be easily provided. Further, from the viewpoint of making the distal end side more flexible, at least a part of the main wire 10, more preferably a narrowed distal end portion, most preferably a portion inserted through the spring coil is on a flat plate called a flat wire. It is a wire.
In the example of FIG. 1, the spring coil 11 includes a radiation opaque coil portion 12 and a radiation transparent coil portion 13. The radiation opaque coil part 12, the radiation transparent coil part 13, and the main wire of the spring coil need to be fixed by fusion welding. That is, the radiation opaque coil portion 12 and the radiation transparent coil portion 13 of the spring coil are joined by fusion welding, and the joining portion is fixed to the main wire by fusion welding. This fixed part will be described later. Throughout this specification, fusion welding means welding without using a brazing agent.
In this example, the radiopaque in-vivo indwelling member mounted on the front end side of the pusher wire for the indwelling member is arranged by disposing the radiopaque coil unit 13 on the front end side of the radiopaque coil unit 12. Clear imaging is possible.
Examples of the material of the radiation transmissive coil portion 13 include stainless steel, copper, aluminum, chromium, nickel, titanium, and alloys thereof. From the viewpoint of facilitating fusion welding, the same material as the main wire is preferable.
Examples of the material of the radiopaque coil section 12 include platinum, gold, tungsten, tantalum, silver, iridium, palladium, and lead. From the viewpoint of processing and contrast, platinum alloys are preferred.
The distal end shape of the spring coil 11 can take any shape according to the living body indwelling member, but includes a shape in which the outer diameter of the coil number pitch is smaller.
Further, when inserting the pusher wire for a living body indwelling member of the present invention into a body lumen, the substantially distal end portion of the spring coil 11 is substantially the distal end of the main wire 10 so that the spring coil 11 does not move to the rear end side. It is preferable to be fixed to the part. The fixing method is not particularly specified, and examples thereof include fusion welding and adhesion that can be precisely processed. From the viewpoint of flexibility, fusion welding is preferred.
The substantially rear end portion of the spring coil 11 is also preferably fixed on the main wire for the same reason. The fixing method is not particularly specified, and examples thereof include fusion welding, brazing, and adhesion. In order to prevent the spring coil 11 from being excessively stretched or frayed, the fixing method is preferably a method having sufficient tensile strength, and brazing is preferable.
Examples of the in-vivo indwelling member referred to in the present specification include an embolization indwelling member.

  FIG. 2 is an enlarged view of the spring coil 11 in which the radiopaque coil part 12 and the radiopaque coil part 13 in FIG. In the example of FIG. 2, the radiopaque coil portion 12 and the radiolucent coil portion 13 are joined by fusion welding. Thereby, it becomes possible to arrange | equalize the axial direction length of the radiation opaque coil part of the spring coil of a pusher wire tip, or a radiation transparent coil part with sufficient precision. Further, the spring coil is firmly fixed to the main wire at the joint between the radiopaque coil portion and the radiopaque coil portion, and the flexibility as a pusher wire is not lost.

  From the viewpoint of the flexibility of the pusher wire, the axial length of the attached welded portion 15 is preferably 1.5 mm or less, and more preferably 0.5 mm or less. Although the minimum of the said length is not specifically limited, From a viewpoint of easy manufacture, it can be 0.1 mm or more.

As the fusion welding (welding method without using a brazing agent), a method of suppressing the heat influence on the peripheral portion of the welding as much as possible is preferable, and laser welding, for example, micro spot welding using a YAG laser or the like is preferable.
FIG. 3 is an explanatory view showing an example of a configuration in which the pusher wire has conductivity, and the pusher wire surface excluding the distal end portion of the spring coil 11 and the end portion of the main wire 10 has an electrically insulating coating 20. Examples of the axial length of the portion that does not have the insulating coating 20 include 0.01 mm from the tip of the spring coil 11 to the rear end and 30 mm from the end of the main wire 10.
The electrically insulating coating 20 can be formed of various polymers such as polyurethane resin, fluororesin, polyethylene, polypropylene, silicone resin, polyamide resin such as nylon, and the like. Can be applied. Further, the coating method may be coating by dipping or spraying or tube coating, but the coating is uniform without pinholes or cracks, and the thickness is preferably 10 μm or more from the viewpoint of ensuring sufficient insulation. On the other hand, from the viewpoint of reducing the pusher wire profile, the insulation thickness is preferably 0.03 mm or less.

  Since the medical wire is disclosed in detail in Japanese Patent Laid-Open No. 7-265431, it will be briefly described below although not shown. The heat-soluble connection member forms a detachment portion for detaching the in-vivo indwelling member, and is formed of a heat-soluble material. As a specific material of the heat-soluble connecting member, a material made of a polyvinyl alcohol copolymer can be preferably used. In this case, the heat-soluble connecting member is heated to a temperature of, for example, 70 ° C. or higher using high-frequency power. It is possible to blow out by heating. An exemplary in-vivo indwelling member is obtained by further spirally winding a primary coil material obtained by spirally winding a filament made of, for example, platinum alloy having compatibility with a living body to form a secondary coil body. The in-vivo indwelling member may be one that uses the primary coil material as it is, and has an appropriate three-dimensional shape other than the secondary coil body that is manufactured using the primary coil material. There may be. As the material of the filament forming the in-vivo indwelling member, a material selected from platinum (platinum), tungsten, gold, tantalum, iridium, palladium and alloys thereof can be used. Specifically, platinum and tungsten are used. Those made of an alloy made of

Example 1
The axial length of the welded portion of the 10 pusher wires in which the radiopaque coil portion, the radiolucent coil portion and the main wire are laser welded is 0.34 ± 0.09 mm, and the axial length of the distal radiolucent coil portion The height was 31.1 ± 0.46 mm.

(Example 2)
The tensile strength of the welded portion of 10 pusher wires in which the radiopaque coil portion, the radiolucent coil portion, and the main wire were laser welded was 2.49 ± 0.14N.

(Comparative Example 1)
The length of the gold brazing portion in the axial direction of 10 pusher wires in which the radiopaque coil portion, the radiolucent coil portion and the main wire are brazed with gold is 1.61 ± 0.49 mm, The axial length was 30.4 ± 1.62 mm.

(Comparative Example 2)
The tensile strength of the bonded portion of 10 pusher wires in which the radiopaque coil portion, the radiation transparent coil portion, and the main wire were bonded with cyanoacrylate was 1.04 ± 0.36N.

It is explanatory drawing which shows an example of a structure of a pusher wire. FIG. 2 is an enlarged view of the spring coil 11 in which the radiopaque coil part 12 and the radiopaque coil part 13 in FIG. It is explanatory drawing which shows an example of the structure by which the pusher wire main body is insulation-coated.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Main wire 11 Spring coil 12 Radiation opaque coil part 13 Radiation transparent coil part 15 Attached weld part 20 Electrical insulation coating

Claims (9)

A flexible main wire,
A spring coil comprising a radiation opaque coil part and a radiation transparent coil part;
One region from the front end portion of the main wire to the rear end side is inserted through the spring coil;
The radiopaque coil portion of the spring coil, the radiolucent coil portion, and the main wire are fixed by fusion welding;
A pusher wire for a living body indwelling member.   2. The pusher wire for an embolization indwelling member according to claim 1, wherein an axial length of the fusion-bonded portion is 0.1 mm or more and 1.5 mm or less.   3. The pusher wire for a living body indwelling member according to claim 1, wherein the fusion welding method is laser welding.   The pusher wire for a living body indwelling member according to any one of claims 1 to 3, wherein in the main wire, at least a part of a portion where the spring coil is mounted is a flat wire.   The pusher wire for a living indwelling member according to any one of claims 1 to 4, wherein the radiopaque coil portion includes at least one selected from the group consisting of platinum, gold, tungsten, tantalum, silver, iridium, palladium, and lead. .   The pusher wire is made of a conductive material, and an insulating coating is further provided on the surface of the pusher wire excluding a tip end portion of the spring coil and a rear end portion of the main wire. The pusher wire for living body indwelling members as described.   The pusher wire for a living body indwelling member according to any one of claims 1 to 6, wherein a distal end portion of the main wire and the spring coil are fixed by fusion welding.   The pusher wire for a living body indwelling member according to any one of claims 1 to 7, further comprising a radiation transmitting coil portion disposed on a distal end side of the radiation opaque coil portion in the spring coil portion. A medical wire, the medical wire
A pusher wire for a living body indwelling member according to any one of claims 1 to 8,
An in-vivo indwelling member connected via a heat-soluble connecting member to the tip of the push-in wire for the indwelling member;
The fusing current is supplied through the pusher wire for the living body indwelling member, so that the connecting member is heated and melted, whereby the indwelling member is removed;
Medical wire with.

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