WO2022080021A1

WO2022080021A1 - Guide wire, and method for manufacturing guide wire

Info

Publication number: WO2022080021A1
Application number: PCT/JP2021/031733
Authority: WO
Inventors: 紘一郎田代
Original assignee: ミズホ株式会社
Priority date: 2020-10-13
Filing date: 2021-08-30
Publication date: 2022-04-21

Abstract

Provided is a guide wire which exhibits high slidability in a blood vessel and a catheter and has excellent productivity.　This guide wire 1 is intended to be inserted into a cerebral blood vessel in the cranium, and is provided with a first core wire 11 which is arranged on the proximal side and a second core wire 12 which is arranged distally to the first core wire 11 and is lineally integrated with the first core wire 11 at a joint part 15, in which the joint part 15 has a smooth outer periphery, a first resin layer 111 is provided between the proximal side of the guide wire 1 and the distal side of the guide wire 1 which excludes the joint part 15, a second resin layer 121 is provided between an end part of the distal side of the guide wire 1 and the proximal side of the guide wire 1 which includes the joint part 15, a distal-side resin end part 113 of the first resin layer 111 and a proximal-side resin end part 123 of the second resin layer 121 are separated away from each other in the direction of the axis of the guide wire 1, and the ratio of the length L2 of the second core wire 12 to the length L1 of the guide wire 1, i.e., L2/L1, is 0.1 or more.

Description

Guide wire and manufacturing method of guide wire

The present invention relates to a guide wire and a method for manufacturing the guide wire.

Conventionally, a guide wire has been used as a medical device for guiding various catheters to a target site in the living lumen. Even in the living lumen into which the guide wire is inserted, the cerebral blood vessels in the skull are thinner and more complicatedly bent than the coronary arterial blood vessels and the like. Therefore, on the distal side of the guide wire inserted into the cerebral blood vessel in the skull, it is flexible so that it can smoothly pass through the small blood vessel (thinner than the puncture site) where the target site is located and the blood vessel wall is not damaged. Need to be increased. On the proximal side, on the other hand, the practitioner's operations (rotation and pushing) need to be stiff so that they are transmitted to the distal side. Therefore, in order to achieve both flexibility on the distal side and operability on the proximal side, a wire material having a low elastic modulus arranged on the distal side and a wire material having a high elastic modulus arranged on the proximal side are arranged. A guide wire integrated by welding has been proposed (see, for example, Patent Document 1).

Japanese Patent No. 4203358

The distal side of the guide wire is coated with a hydrophilic resin in order to improve the lubricity with blood. Further, the proximal side is coated with fluororesin in order to reduce the frictional resistance with the inner wall of the catheter when the catheter is externally inserted into the guide wire. In this way, when the distal side and the proximal side of the guide wire are coated with different resins, when the joints of the two resin layers overlap, the overlapped part swells, so that the inner wall of the externalized catheter The frictional resistance of is partially increased. Further, due to the frictional resistance with the inner wall of the catheter, a part of the resin layer on the outer side of the overlapped portion may be peeled off. If the resin is coated so that the seams of the two resin layers match, the work of coating the resin takes time and effort, and thus the productivity is lowered. Further, since the heat treatment is performed when the resin is coated, the heat generated at that time may affect the welded portion. On the other hand, it is also possible to coat each wire material with resin and then integrate them by welding, but the coated resin layer interferes with welding, or a part of the resin layer is peeled off by the heat generated during welding. There is a risk of

An object of the present invention is to provide a guide wire and a method for manufacturing a guide wire having high slidability in a blood vessel and a catheter and excellent in productivity.

One embodiment of the present invention is a guide wire inserted into a cerebral blood vessel in the skull, which is a first core wire provided on the proximal side and a second core wire provided on the distal side of the first core wire. A second core wire that is linearly integrated with the guide wire at the joint is provided, and the joint has a smooth outer peripheral portion and does not include the joint portion from the proximal side of the guide wire. A first resin layer is provided between the distal side and a second resin layer is provided between the distal end of the guide wire and the proximal side including the joint, and the first resin is provided. The resin end on the distal side of the layer and the resin end on the proximal side of the second resin layer are separated in the axial direction of the guide wire, and the second resin end with respect to the length L1 of the guide wire is separated. The ratio L2 / L1 of the length L2 of the two core wires is 0.1 or more.

In the above invention, the second core wire may be made of a material having a relatively lower elastic modulus than the first core wire.

In the above invention, the first resin layer may contain a fluororesin, and the second resin layer may contain a hydrophilic resin.

In the above invention, the length L3 between the resin end portion and the joint portion of the first resin layer may be 2 to 50 mm.

In the above invention, the length L4 between the resin end portion and the joint portion of the second resin layer may be 2 to 50 mm.

In the above invention, the distance L5 between the resin end portion of the first resin layer and the resin end portion of the second resin layer may be 2 to 50 mm.

Another embodiment of the present invention is a first core wire provided on the proximal side and a second core wire provided on the distal side of the first core wire as a guide wire inserted into a cerebral blood vessel in the skull. The ratio L2 / L1 of the length L2 of the second core wire to the length L1 of the guide wire is 0.1 or more. A step of coating the first resin layer between the proximal side of the first core wire and the distal side of the first core wire, which does not include the wire end, in the method of manufacturing the guide wire. And the step of abutting and joining the wire end portion on the distal side of the first core wire and the wire end portion on the proximal side of the second core wire to form the joint portion, and the outer peripheral portion of the joint portion. Between the step of smoothing and the distal end of the guide wire to the proximal side including the junction, the distal resin end of the first resin layer and the second resin layer are close to each other. It has a step of covering the second resin layer so as to be separated from the resin end portion on the position side in the axial direction of the guide wire.

In another embodiment of the above invention, the step of coating the second resin layer is a raw material of the second resin layer from the distal end portion of the guide wire to the proximal side including the joint portion. A step of immersing in a solution of the resin and then pulling it out of the solution to dry it may be included.

According to the present invention, it is possible to provide a guide wire and a method for manufacturing a guide wire having high slidability in a blood vessel and a catheter and excellent in productivity.

It is a side view of the guide wire 1 of an embodiment. It is the schematic sectional drawing of the part corresponding to the region b of FIG. It is a figure explaining the manufacturing method of the guide wire 1. It is a figure explaining the manufacturing method of the guide wire 1. It is a figure explaining the manufacturing method of the guide wire 1. It is a figure explaining the manufacturing method of the guide wire 1.

Hereinafter, embodiments of the guide wire according to the present invention will be described. The drawings attached to the present specification are all schematic views, and the shape, scale, aspect ratio, etc. of each part are changed or exaggerated from the actual product in consideration of ease of understanding. For example, the longitudinal direction of the guide wire 1 is shortened and the radial direction is shown thick.

In the present specification and the like, terms that specify the shape, geometric conditions, and the degree thereof, for example, terms such as "parallel" and "direction", can be regarded as almost parallel in addition to the strict meaning of the terms. Includes a range of degrees, a range that can be generally regarded as that direction. Further, in the present specification, the direction parallel to the central axis a (see FIG. 1) in the state where the guide wire 1 is extended in a straight line is also referred to as "axial direction X". Then, in the axial direction X, the proximal side close to the practitioner will be referred to as the X1 side, and the distal side away from the practitioner will be referred to as the X2 side.

FIG. 1 is a side view of the guide wire 1 of the present embodiment. FIG. 2 is a schematic cross-sectional view of a portion corresponding to the region b in FIG. The guide wire 1 of the present embodiment is used, for example, in the skull for adjusting the position of a catheter or the like used for treating cerebrovascular disease and assisting the movement (guidance to a target position).
As shown in FIG. 1, the guide wire 1 includes a core wire 10, a contrast coil 20, a coil 30, and a tip fixing portion 40. The core wire 10 is composed of a first core wire 11 and a second core wire 12.

The first core wire 11 is a linear wire material constituting the proximal side (X1 side) of the core wire 10. As described above, the first core wire 11 on the proximal side of the guide wire 1 enhances the transmission of force in the axial direction X, and facilitates the transmission of the practitioner's operation (rotation or pushing) to the distal side. In order to do so, it needs to be stiff. Therefore, the first core wire 11 is made of a material having a high elastic modulus such as stainless steel. The outer diameter of the first core wire 11 is, for example, 0.02 to 0.05 mm.

As shown in FIG. 2, the outer peripheral surface of the first core wire 11 is covered with a first resin layer 111 made of a fluororesin. The first resin layer 111 is a layer coated to reduce the frictional resistance with the inner wall of the catheter when the catheter (not shown) is externally inserted into the guide wire 1. By covering the outer peripheral surface of the first core wire 11 with the first resin layer 111, the frictional resistance with the inner wall of the externalized catheter is reduced, so that the slidability can be further improved. The first resin layer 111 may be covered only in the range to be inserted into the catheter in the first core wire 11. That is, the first resin layer 111 does not necessarily have to be covered from the proximal end to the distal side of the first core wire 11. The average layer thickness of the first resin layer 111 is, for example, 3 to 15 μm. As will be described later, the first resin layer 111 is coated on the outer peripheral surface of the first core wire 11 before welding (joining) the first core wire 11 and the second core wire 12.

The second core wire 12 is a linear wire material constituting the distal side (X2 side) of the core wire 10. As described above, the second core wire 12 on the distal side of the guide wire 1 needs to be more flexible in order to smoothly pass through a small blood vessel having a target site and not to damage the blood vessel wall. Therefore, the second core wire 12 is made of a material having a low elastic modulus and excellent shape restoration, such as a nickel titanium (Ni—Ti) alloy. The elastic modulus of the second core wire 12 is set to be relatively lower than the elastic modulus of the first core wire 11. The outer diameter of the second core wire 12 is, for example, 0.02 to 0.05 mm.

As described above, in the core wire 10 of the present embodiment, the first core wire 11 on the proximal side is made of a material having a high elastic modulus, and the second core wire 12 on the distal side is made of a material having a low elastic modulus. ing. Therefore, the guide wire 1 provided with the core wire 10 can further reduce the burden on the blood vessel wall in the bent blood vessel, and is excellent in the transmission of the rotational force and the axial force by the operation of the practitioner.
Assuming that the guide wire 1 of the present embodiment is inserted into the cerebral blood vessel in the skull, the total length of the guide wire 1 is, for example, about 2000 to 4000 mm. In FIG. 1, the ratio L2 / L1 of the length L2 of the second core wire 12 to the length L1 of the guide wire 1 is 0.1 to 0.5.

As shown in FIG. 2, the outer peripheral surface of the second core wire 12 is covered with a second resin layer 121 made of a hydrophilic resin. The second resin layer 121 is a layer coated to improve the lubricity with blood when the second core wire 12 comes into contact with blood in the blood vessel. Examples of the hydrophilic resin constituting the second resin layer 121 include polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), maleic anhydride copolymer compound, hyaluronic acid and the like. By covering the outer peripheral surface of the second core wire 12 with the second resin layer 121, the lubricity with blood can be improved due to the wettability of the hydrophilic resin. The average layer thickness of the second resin layer 121 is, for example, 3 to 15 μm.

As will be described later, the second resin layer 121 is coated on the outer peripheral surface of the second core wire 12 after joining the first core wire 11 and the second core wire 12 to smooth the outer peripheral surface of the joint portion 15. .. A contrast coil 20 or the like (described later) is provided on the tip end side (X2 side) of the second core wire. Therefore, the second resin layer 121 is covered with the outer surface of the members such as the contrast coil 20 on the distal end side of the second core wire 12 in the region where the members are extrapolated.

As shown in FIG. 1, the contrast coil 20 is a spiral member externally attached to the distal side (X2 side) of the second core wire 12. The contrast coil 20 serves as a mark for confirming the position of the tip of the guide wire 1 in the X-ray transmission image. The contrast coil 20 is made of a material that is impermeable to radiation such as X-rays and can be molded into a coil shape. Examples of the material constituting the contrast coil 20 include platinum tungsten (Pt—W) alloy, platinum-iridium (Pt—Ir) alloy, gold, tantalum and the like. A hemispherical tip fixing portion 40 is provided on the distal side (X2 side) of the contrast coil 20.

The coil 30 is a spiral member externally attached to the proximal side (X1 side) of the contrast coil 20. By extrapolating the coil 30 to the second core wire 12, the second core wire 12 can be made hard to break and can be made flexible. Examples of the material constituting the coil 30 include stainless steel, tungsten, nickel-titanium alloy and the like. The contrast coil 20, the coil 30, and the tip fixing portion 40 are fixed to the second core wire 12 by soldering.

Next, the positional relationship between the resin ends of the first resin layer 111 and the second resin layer 121 in the axial direction X will be described.
As shown in FIG. 2, the wire end portion 112 on the distal side (X2 side) of the first core wire 11 and the wire end portion 122 on the proximal side (X1 side) of the second core wire 12 are joined at the joint portion 15. And are integrated linearly. The respective wire ends of the first core wire 11 and the second core wire 12 can be joined by butt welding such as butt welding and upset welding, for example. As will be described later, when the wire ends of the first core wire 11 and the second core wire 12 are welded, the outer peripheral portion of the joint portion 15 has a bulging shape (see FIG. 3B). This swollen outer peripheral portion is smoothed in a later process. By smoothing the outer peripheral portion of the joint portion 15, the slidability at the joint portion between the first core wire 11 and the second core wire 12 can be improved. In FIG. 2, the signed arrow indicating the position of the joint portion 15 points to the joint surface between the first core wire 11 and the second core wire 12. The joint surface is a portion where the wire ends of both wire materials are melted together. The joint portion 15 shown in FIG. 2 includes a joint surface and an outer peripheral portion smoothed from a bulging shape.

The resin end 113 of the first resin layer 111 covered with the first core wire 11 is located proximal to the joint 15. In the first core wire 11, the length L3 between the resin end portion 113 and the joint portion 15 of the first resin layer 111 is configured to be 2 to 50 mm, preferably 10 to 20 mm.
The second resin layer 121 coated on the second core wire 12 covers the outer peripheral portion of the joint portion 15. Further, the resin end portion 123 of the second resin layer 121 is located proximal to the joint portion 15. In the second core wire 12, the length L4 between the resin end portion 123 and the joint portion 15 of the second resin layer 121 is configured to be 2 to 50 mm, preferably 10 to 30 mm.

By adjusting the lengths L3 and L4 shown in FIG. 2 within the above range, the distance L5 between the resin end 113 of the first resin layer 111 and the resin end 123 of the second resin layer 121 can be set to 2 to 50 mm. It can be preferably in the range of 3 to 15 mm. By approaching the interval L5 to the upper limit value, it is less likely that the resin layers are erroneously overlapped with each other, so that the manufacturing yield of the guide wire 1 can be improved. Further, by approaching the interval L5 to the lower limit value, the unevenness of the surface of the guide wire 1 becomes smaller, so that the slidability of the guide wire 1 can be improved. The interval L5 is appropriately selected in the range of 2 to 50 mm based on the outer diameter of the core wire 10, the layer thickness of each resin layer, the product specifications, and the like.

Next, the method for manufacturing the guide wire 1 described above will be described. 3A to 3D are diagrams illustrating a method of manufacturing the guide wire 1.
First, the outer peripheral surface of the first core wire 11 is covered with the first resin layer 111. Various methods can be used for coating the first resin layer 111. For example, the first core wire 11 may be sprayed with a liquid resin to cover it and fired by heat treatment, or the first core wire 11 may be continuously coated with the resin by an extrusion molding machine. Further, the outer peripheral surface of the first core wire 11 can be covered by externally inserting a tubular fluororesin into the first core wire 11 and heating and shrinking the resin.

When the outer peripheral surface of the first core wire 11 is coated with the first resin layer 111, the first core wire 11 and the second core wire 12 are not yet joined. Therefore, the processing heat applied to the core wire when coating with the first resin layer 111 affects the welded portion (joint portion 15), and affects the delicate shape, design dimensions, etc. on the distal side of the second core wire 12. Is not given. The first resin layer 111 is covered so that the length L3 (see FIG. 2) between the resin end portion 113 and the joint portion 15 is 2 to 50 mm.
After covering the outer peripheral surface of the first core wire 11 with the first resin layer 111, as shown in FIG. 3A, the wire end portion 112 on the distal side (X2 side) of the first core wire 11 and the vicinity of the second core wire 12 The wire ends 122 on the position side (X1 side) are opposed to each other, and both wire ends are abutted against each other.

Next, as shown in FIG. 3B, the wire end 112 of the first core wire 11 and the wire end 122 of the second core wire 12 are joined by butt welding such as the above-mentioned butt welding. By performing butt welding, the joint portion of both wire end portions becomes the joint portion 15. When welding the first core wire 11 and the second core wire 12, the resin end portion 113 (see FIG. 2) of the first resin layer 111 coated on the first core wire 11 is separated from the joint portion 15 by a length L4. Therefore, it does not easily interfere with welding. At the time of welding, the wire ends of both wire materials are joined by melting each other, so that the outer peripheral portion of the joint portion 15 has a shape bulging in the outer diameter direction as shown in FIG. 3B. ..

Next, as shown in FIG. 3C, the outer peripheral portion of the joint portion 15 is smoothed. The outer peripheral portion of the joint portion 15 may be smoothed by using, for example, a cutting tool, an abrasive, or the like, or may be smoothed by a chemical treatment. The outer peripheral portion of the joint portion 15 is covered with the second resin layer 121 in a subsequent step. Therefore, the joint portion 15 may be in a state of substantially no unevenness, and may not be a completely smooth surface.

Next, as shown in FIG. 3D, the outer peripheral surface of the second core wire 12 is covered with the second resin layer 121. The second resin layer 121 can be covered, for example, by immersing the portion of the second core wire 12 in a solution of the hydrophilic resin, then pulling it out of the solution and drying it. The second resin layer 121 is covered so that the length L4 (see FIG. 2) between the resin end portion 123 and the joint portion 15 is 2 to 50 mm. As a result, the joint portion 15 is covered with the second resin layer 121, and the distance L5 (see FIG. 2) between the resin end portion 113 of the first resin layer 111 and the resin end portion 123 of the second resin layer 121 is increased. A guide wire 1 having a size of 2 to 50 mm can be obtained.

According to the guide wire 1 of the above-described embodiment, the resin end portion 113 of the first resin layer 111 and the resin end portion 123 of the second resin layer 121 are separated from each other in the axial direction X of the guide wire 1. .. Therefore, due to the overlap of the seams of the two resin ends, the frictional resistance with the inner wall of the externalized catheter (not shown) does not partially increase, and a part of the resin layer outside the overlapped portion is formed. It will not come off. In particular, by setting the distance L5 to 2 to 50 mm, it is possible to minimize the decrease in slidability due to the seams of the two resin ends being separated from each other. Further, since it is not necessary to match the seams of the two resin ends, the work of covering each resin layer can be made more efficient, and the yield of the product can be improved. Therefore, the guide wire 1 of the present embodiment has high slidability in the blood vessel and the catheter, and is also excellent in productivity.

According to the guide wire 1 of the embodiment, the first resin layer 111 is covered on the outer peripheral surface of the first core wire 11 before welding the first core wire 11 and the second core wire 12. Therefore, the heat generated when the tubular fluororesin to be the first resin layer 111 is shrunk affects the welded portion (joint portion 15), and the delicate shape and design dimensions on the distal side of the second core wire 12 It does not affect such things.

In the manufacturing method of the embodiment, the guide wire is first coated with the first resin layer 111 on the first core wire 11, bonded to the second core wire 12, and then coated with the second resin layer 121 on the second core wire 12. 1 is manufactured. On the other hand, the guide wire 1 is manufactured by first coating the second core wire 12 with the second resin layer 121, joining the second core wire 11 with the first core wire 11, and then coating the first core wire 11 with the first resin layer 111. Is also possible. However, in this manufacturing method, the heat generated when the first resin layer 111 is coated (heat treated) affects the welded portion (joint portion 15), or the delicate shape and design on the distal side of the second core wire 12 are designed. Since it may affect the dimensions, etc., the yield of the product decreases.

On the other hand, according to the method for manufacturing the guide wire 1 of the embodiment, when the first core wire 11 is coated with the first resin layer 111 that requires heat treatment, the first core wire 11 is joined to the second core wire 12. It has not been. Therefore, the heat generated when coating the first resin layer 111 does not affect the joint portion 15, or the delicate shape, design dimensions, etc. on the distal side of the second core wire 12. Therefore, according to the method for manufacturing the guide wire 1 of the embodiment, the yield of the product is improved, so that the productivity of the guide wire 1 can be further increased.
According to the guide wire 1 of the embodiment, when the first core wire 11 and the second core wire 12 are welded, the ends of both core wires are exposed, so that the welding work and the subsequent smoothing work are easy. Can be done.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made as in the modified forms described later, and these are also the present invention. Included within the technical scope of. Moreover, the effects described in the embodiments are merely a list of the most suitable effects resulting from the present invention, and are not limited to those described in the embodiments. The above-described embodiment and the modified form described later may be used in combination as appropriate, but detailed description thereof will be omitted.

(Deformed form)
In the embodiment, an example in which the outer peripheral surface of a member such as the contrast coil 20 provided on the tip end side of the second core wire 12 is covered with the second resin layer 121 has been described, but the present invention is not limited thereto. When the member is not provided on the tip end side of the second core wire 12, the entire surface including the tip end side of the second core wire 12 may be covered with the second resin layer.

1 Guide wire 10 Core wire 11 1st core wire 12 2nd core wire 15 Joint part 20 Contrast coil 30 Coil 40 Tip fixing part 111 1st resin layer 112 Wire end 113 Resin end 121 2nd resin layer 122 Wire end 123 Resin end Department

Claims

A guide wire that is inserted into the cerebral blood vessels in the skull.
A first core wire provided on the proximal side, a second core wire provided on the distal side of the first core wire, and a second core wire linearly integrated with the first core wire at a joint. Equipped with
The joint has a smooth outer peripheral portion and has a smooth outer peripheral portion.
A first resin layer is provided between the proximal side of the guide wire and the distal side not including the joint.
A second resin layer is provided between the distal end of the guide wire and the proximal side including the joint.
The resin end on the distal side of the first resin layer and the resin end on the proximal side of the second resin layer are separated in the axial direction of the guide wire.
The ratio L2 / L1 of the length L2 of the second core wire to the length L1 of the guide wire is 0.1 or more.
Guide wire.
The second core wire has a relatively lower elastic modulus than the first core wire.
The guide wire according to claim 1.
The first resin layer contains a fluororesin and contains
The second resin layer contains a hydrophilic resin.
The guide wire according to claim 1 or 2.
The length L3 between the resin end portion and the joint portion of the first resin layer is
2 to 50 mm,
The guide wire according to any one of claims 1 to 3.
The length L4 between the resin end portion and the joint portion of the second resin layer is 2 to 50 mm.
The guide wire according to any one of claims 1 to 4.
The distance L5 between the resin end portion of the first resin layer and the resin end portion of the second resin layer is
2 to 50 mm,
The guide wire according to any one of claims 1 to 5.
As a guide wire to be inserted into a cerebral blood vessel in the skull, a first core wire provided on the proximal side and a second core wire provided on the distal side of the first core wire, the first core wire at a joint. A guide wire manufacturing method comprising a second core wire linearly integrated with the guide wire, wherein the ratio L2 / L1 of the length L2 of the second core wire to the length L1 of the guide wire is 0.1 or more. There,
A step of coating the first resin layer from the proximal side of the first core wire to the distal side not including the wire end on the distal side of the first core wire.
A step of abutting and joining a wire end on the distal side of the first core wire and a wire end on the proximal side of the second core wire to form the joint.
The step of smoothing the outer peripheral portion of the joint portion and
Between the distal end of the guide wire and the proximal side including the joint, the resin end on the distal side of the first resin layer and the resin end on the proximal side of the second resin layer. And the step of coating the second resin layer so as to be separated from each other in the axial direction of the guide wire.
A method of manufacturing a guide wire having.
The step of coating the second resin layer is
A step of immersing the guide wire from the distal end to the proximal side including the joint in a solution of the raw material resin of the second resin layer, and then pulling up from the solution to dry the guide wire.
The method for manufacturing a guide wire according to claim 7.