JP2011147753A - Guide wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a guide wire having sufficient rigidity for guiding devices such as a micro-catheter, retaining the shape when the guide wire is shaped, and having high stability. <P>SOLUTION: The guide wire 10 includes an inner coil 50 made of a plurality of entwined wires for surrounding the distal end of a core shaft 14, and an outer coil 60 including a roughly wound part 62a with wires wound separately from one another on the distal end side and a tightly wound part with wires wound in contact with one another on the rear end side for surrounding the inner coil 50 and the distal end side of the core shaft 14. An inner rear end joint 52 of the inner coil 50 joins the rear end of the inner coil 50 to the core shaft 14 only on the rear end side of the roughly wound part 62a of the outer coil 60 and on the distal end side of an outer rear end joint 64 of the outer coil 60. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a medical guide wire.

Conventionally, various medical guidewires have been proposed for guiding tubular organs such as blood vessels, gastrointestinal tracts, ureters, etc., and catheters used by being inserted into body tissues for treatment and examination. Some guidewires have a structure in which a double coil is provided at the tip of the core shaft (for example, see Patent Documents 1 and 2 below), and others that use a stranded wire made of a plurality of strands in the coil. (For example, see Patent Document 3 below).
Generally, the guide wire is required to have flexibility on the distal end side (distal side) and rotation follow-up property that transmits a rotation operation performed by the operator to the distal end side on the rear end side (base end side).

Japanese National Patent Publication No. 6-501179 JP 2006-511304 Gazette JP 2008-161491 A

In recent years, the range of use of guidewires has tended to be expanded, and is used for blood vessels on the peripheral side of the heart, blood vessels in the brain, and the like. For this reason, higher safety is required, and flexibility and rotation follow-up are further required.
In particular, since the blood vessels of the brain are very delicate parts, not only damage to the blood vessels and the tissues surrounding them but also high rotation followability is required.
This invention is made | formed in view of such a situation, and makes it a subject to provide a guide wire with high safety | security, and the softness | flexibility and rotation followability improved.

In addition, the guide wire used for the blood vessel of the brain not only requires flexibility in order not to damage the inside of the blood vessel, but also needs a certain rigidity to guide the microcatheter. In order to increase the rigidity, it is generally sufficient to increase the diameter of the core shaft, but not only the flexibility is lost, but there is a possibility that the shape when shaping is maintained and the restoration property is deteriorated. . In other words, when a guide wire is used, an operation such as shaping is often performed by an operator such as a doctor by bending the tip portion, but when the diameter is increased to increase the rigidity of the core shaft, Although shaping is easy, the angle of shaping changes during use in a blood vessel, making it difficult to maintain that angle. In addition, due to the load acting on the guide wire in the bent blood vessel, the distal end portion of the core shaft is bent and a residual angle is generated without being restored.
The present invention has been made in view of such circumstances, and a guide wire that has sufficient rigidity to guide a device such as a microcatheter, retains the shape when shaped, and has high recoverability. The issue is to provide.

  In the invention of the present application, the above problem is solved by the means listed below.

<1> A core shaft and a plurality of strands are twisted together, an inner coil surrounding the tip side portion of the core shaft, and at least one strand is wound, and the strands are wound on the tip side. Have a loosely wound portion wound so as to be separated from each other, and a densely wound portion wound so that the strands are in contact with each other on the rear end side, and the tip of the inner coil and the core shaft An outer coil that surrounds the side, a tip joint that joins the tip of the outer coil and the tip of the inner coil to the tip of the core shaft, and an outer rear that joins the rear end of the outer coil to the core shaft An inner rear end that joins the rear end of the inner coil only to the core shaft on the rear end side of the outer coil and the outer coil at the rear end side of the end coil and the outer coil. It is characterized by having a joint Guidewire.

<2> The outer coil is made of a wire made of a radiopaque material on the front end side, at least a part on the front end side is the sparsely wound portion, and a radiopaque portion on the rear end side. A transmission portion consisting only of the densely wound portion, and the inner rear end joint portion of the inner coil is located on the rear end side with respect to the impermeable portion. The guide wire according to aspect 1, which is characterized.

<3> The outer coil includes an outer intermediate joint that joins the outer coil to the core shaft between the tip joint and the outer rear joint, and the inner rear joint of the inner coil. The guide wire according to the aspect 1 or 2, wherein the portion is located on the distal end side with respect to the outer intermediate joint portion.

<4> The outer intermediate joint portion of the outer coil is located at an intermediate taper portion where the core shaft becomes thinner toward the tip side, and the inner rear end joint portion of the inner coil is more than the intermediate taper portion. The above aspect 3 is characterized in that the core shaft is located at a tip side taper portion that becomes narrower toward the tip side on the tip side, and an inclination angle of the intermediate taper portion is different from an inclination angle of the tip side taper portion. Guide wire as described.

<5> From the above aspect 1, wherein a coil joint for joining only the outer coil and the inner coil to each other is provided between the tip joint and the inner rear end joint of the inner coil. 5. The guide wire according to any one of the four aspects.

<6> The guide wire according to Aspect 5, wherein the outer coils are closely wound so that the strands come into contact with each other on the rear end side of the coil joint portion.

<7> The tip side portion of the core shaft surrounded by the front inner coil has a cylindrical shape having at least two different diameters, a large-diameter flexible portion and a small-diameter flexible portion having a smaller diameter than the large-diameter flexible portion. The guide wire according to any one of the above aspects 1 to 6, wherein the guide wire has a portion.

<8> The guide wire according to aspect 7, wherein the small-diameter flexible portion is disposed at a position corresponding to the loosely wound portion of the outer coil.

<9> The guide wire according to any one of the above aspects 1 to 8, wherein a flat portion having at least two opposed flat portions is provided at a tip of the core shaft.

<1> In the guide wire according to the first aspect, the distal end portion of the guide wire is protected by a double coil structure including an inner coil in which an outer coil and a plurality of strands are combined. In this double coil structure, the outer coil has a loosely wound portion on the distal end side, whereby the flexibility of the distal end portion of the guide wire can be improved. With such a structure in which the loosely wound portion is added to the double structure, the guide wire comes into contact with the blood vessel wall or the like at the flexible coil portion in the body, so that damage to the blood vessel or the like can be prevented as much as possible.
Moreover, the guide wire of aspect 1 can not only improve rotation followability and push-in characteristics by the inner coil constituted by the stranded wire, but the inner rear end joint portion of the inner coil is joined to the outer coil. In addition, it is joined only to the core shaft, and is biased to the rear end side with respect to the boundary between the loosely wound portion and the densely wound portion of the outer coil. With this structure, the inner rear end joint portion of the inner coil is made as small as possible to prevent the change in rigidity of the core shaft as much as possible, and at the boundary between the loosely wound portion and the densely wound portion of the outer coil. It is possible to prevent the change in rigidity and the change in the rigidity of the core shaft due to the inner rear end joint portion of the inner coil from being concentrated. Therefore, since the rigidity of the distal end portion of the guide wire is prevented from abruptly changing and the torque applied from the proximal side of the guide wire can be prevented as much as possible from being lost in the middle of the guide wire, the rotation of the guide wire can be prevented. Followability and indentation characteristics can be further improved.

Furthermore, since the guide wire of aspect 1 can secure the rigidity of the tip portion of the core shaft by the inner coil, the catheter is guided even if the diameter of the portion surrounded by the inner coil at the tip side portion of the core shaft is reduced. It can be provided with sufficient rigidity. Furthermore, when the tip of the guide wire is shaped with the inner coil and core shaft having a reduced diameter, it is not plastically deformed even if the shaping angle changes when it is inserted into a body such as a blood vessel. Restore and preserve the shaping angle. Further, even if an external force acts on the distal end side portion of the guide wire due to a bent blood vessel or the like, plastic deformation can be prevented as much as possible, and the restoring force can be improved.
Further, the outer coil can be easily shaped even if it has a double coil structure by a loosely wound portion on the tip side.

<2> In the aspect 2 of the invention, the rigidity is high in the order of the loosely wound portion of the opaque portion made of a radiopaque material, the densely wound portion, and the transparent portion made of only the densely wound portion made of the radiation transparent material. Therefore, the guide wire has a highly safe structure with a flexible tip.
In addition, since the inner rear end joining portion of the inner coil is arranged not only on the boundary between the loosely wound portion and the densely wound portion but also on the rear end side than the boundary between the non-transmissive portion and the transmissive portion, It is possible to prevent the change in rigidity generated at the boundary and the change in the rigidity of the core shaft due to the inner rear end joint portion of the inner coil from being concentrated. Accordingly, it is possible to prevent the rigidity of the distal end portion of the guide wire from changing suddenly, and to further improve the rotation followability and pushing characteristics of the guide wire.

<3> In aspect 3 of the invention, the inner rear end joint portion of the inner coil is located on the front end side of the outer intermediate joint portion and is not joined to the outer intermediate joint portion, so that the rigidity of the guide wire is rapidly increased. Changes can be prevented as much as possible. For this reason, the rotational force and pushing force given from the proximal side of the guide wire can be efficiently transmitted to the distal end side, and torque transmission is improved.

<4> In the aspect 4 of the invention, the inclination angle is different between the intermediate taper portion where the outer intermediate joint portion of the outer coil is located and the tip side taper portion where the inner rear end joint portion of the inner coil is located. Yes. That is, the taper inclination angle changes between the intermediate taper portion where the inner coil does not exist and the tip taper portion where the inner coil exists. Since the change in the inclination of the intermediate taper portion cancels out the increase in rigidity caused by the inner coil as much as possible, the rigidity of the guide wire is rapidly increased due to the inner coil being disposed at the tip portion of the core shaft. Changes can be prevented. Accordingly, it is possible to further improve the rotation followability and pushing characteristics of the guide wire.

<5> In the aspect 5 of the invention, not only rotation followability is improved by the inner coil, but also rotation applied from the rear end side of the core shaft by joining the outer coil and the inner coil by the coil joint portion. Can be transmitted from the outer coil to the inner coil, so that the rotation followability is further improved.
Furthermore, the coil joint only joins the outer coil and the inner coil, and not the core shaft, so that the flexibility of the inner coil and the outer coil can be prevented as much as possible from being reduced. Can be maintained.

<6> In aspect 6 of the invention, since the outer coil is closely wound on the rear end side from the coil joint portion so that the strands are in contact with each other, the rotation applied from the rear end side of the core shaft is from the outer coil. When transmitting also to the inner coil, it is possible to prevent the transmission of rotation from being damaged by the gap between the strands as much as possible, so that the rotation followability is further improved.

<7> In aspect 7 of the invention, the core shaft is formed by dividing the tip portion of the core shaft located inside the inner coil into at least two portions having different rigidity, that is, a small-diameter flexible portion and a large-diameter flexible portion, thereby reducing the diameter. Not only can the change in shaft rigidity be moderated, but it is also possible to reduce the diameter to improve the shape retention and restoration of the shaping and to ensure the rigidity to better guide devices such as microcatheter. It becomes possible.
That is, by having the inner coil, it is possible to reduce the diameter of the tip portion of the core shaft, which contributes to the shape retention and resilience of the shaping. On the other hand, if the range in which the diameter is reduced too much is too long, it is disadvantageous in terms of securing rigidity when guiding a device such as a microcatheter. Therefore, even in the inner coil, it is possible to achieve both of these characteristics by making the change in rigidity stepwise.

<8> In aspect 8 of the invention, the small-diameter flexible portion at the tip of the core shaft is located at a position corresponding to the loosely wound portion of the outer coil, so that even if there is an inner coil, the outer coil becomes a loosely wound portion. Therefore, it is easy to bend the distal end portion of the guide wire, and it is easy for the operator to shape the thinned portion.

<9> In the ninth aspect of the invention, since the torsional rigidity is increased by providing the flat portion at the tip of the core shaft, the direction of the catheter can be easily changed by the guide wire. Also, when performing such work, there is a possibility that a load acts on the boundary with the flat part, but by providing the inner coil, the load is shared by the inner coil, and the core shaft is bent or broken. Can be prevented as much as possible.

FIG. 1 is an overall view of a guide wire according to the present embodiment. FIG. 2 is a partially enlarged view of FIG. FIG. 3 is a view showing the most distal portion of the guide wire according to the present embodiment. FIG. 4 is a top view of FIG. FIG. 5 is a graph showing the rotational followability of the guide wire of the present embodiment. FIG. 6 is a view showing the data measuring apparatus of FIG. FIG. 7 is a graph comparing holding characteristics of the shaping shape of the guide wire according to the present embodiment. FIG. 8 is a graph comparing the recoverability of the guide wire of the present embodiment. FIG. 9 is a diagram for explaining the operation of the guide wire according to the present embodiment.

The guide wire of this Embodiment is demonstrated referring FIGS. 1-4. 1 to 4, the right side in the figure is the distal end side (distal side) inserted into the body, and the left side is the rear end side (base end side, proximal side) operated by the operator.
The guide wire 10 is used for treatment of blood vessels in the brain. For example, in the case of the present embodiment, the guide wire 10 has a length of about 2000 mm.
The guide wire 10 mainly includes a core shaft 14, an inner coil 50, and an outer coil 60. The core shaft 14 is roughly divided into a main body portion 20, a tip portion 30, and a most distal portion 40. A hydrophilic coating is applied to the outer surface of the main body 20 from the distal end of the guide wire 10 through the outer coil 60 to a predetermined range.
The tip portion 30 and the most distal portion 40 are portions where the core shaft 14 is reduced in diameter, and the total length in the axial direction of both is about 420 mm in the present embodiment. The main body portion 20 is a cylindrical portion having a constant diameter and occupies a portion other than the tip portion 30 and the most distal portion 40. In the present embodiment, the diameter of the main body 20 is set to about 0.33 mm.
The material of the core shaft 14 is not particularly limited, but in the case of the present embodiment, stainless steel (SUS304) is used. As other materials, a super elastic alloy such as a Ni-Ti alloy, a piano wire, or the like is used.

The tip portion 30 has a first taper portion 31, a first small diameter portion 32, a second taper portion 33, a third taper portion 34 (intermediate taper portion), and a fourth taper in order from the main body portion 20 side toward the most distal portion 40. A portion 35 (tip tapered portion) is provided. In the present embodiment, the axial lengths of the first tapered portion 31 and the first small diameter portion 32 are each about 100 mm.
The first tapered portion 31 is a tapered portion having a circular cross section, and in the present embodiment, the diameter decreases from about 0.33 mm to about 0.20 mm in the distal direction.
The first small diameter portion 32 is a cylindrical portion having a circular cross section and a constant diameter. In the present embodiment, the diameter is about 0.20 mm.
The 2nd taper part 33, the 3rd taper part 34, and the 4th taper part 35 are each a taper-shaped part with a circular cross section from which an inclination angle differs, respectively. In the present embodiment, the total axial length of the second taper portion 33, the third taper portion 34, and the fourth taper portion 35 is about 205 mm. In addition, the diameter is set to decrease from about 0.20 mm to about 0.05 mm from the proximal end of the second tapered portion 33 to the distal end of the fourth tapered portion 35.
Between each taper part 33,34,35, it is also possible to provide a cylindrical part with a constant diameter as needed. Further, the number of taper portions and the taper angle can be appropriately set as necessary.

The most advanced portion 40 is provided with a large-diameter flexible portion 41, a small-diameter flexible portion 42, a first flat portion 43, and a second flat portion 44 in order from the tip portion 30 side to the tip. In the present embodiment, the length in the axial direction of the most distal portion 40 is about 15 mm.
The large-diameter flexible portion 41 and the small-diameter flexible portion 42 are cylindrical portions having a circular cross section and a constant diameter. The diameter of the small-diameter flexible part 42 is set to be smaller than the diameter of the large-diameter flexible part 41, and the small-diameter flexible part 42 and the large-diameter flexible part 41 are connected by a small taper part 45 provided between them. ing.

Thus, by dividing the tip 40 located inside the inner coil 50 into the small-diameter flexible portion 42 and the large-diameter flexible portion 41 and reducing the diameter, the rigidity change of the core shaft 14 can be moderated. In addition, it is possible to achieve both a reduction in the diameter for improving the retention and restoration of the shape of the shaping and the securing of rigidity for better guiding the device such as the microcatheter.
That is, by having the inner coil 50, it is possible to reduce the diameter of the foremost portion 40, which contributes to shape retention and restoration of shaping. On the other hand, if the range in which the diameter is reduced too much is too long, it is disadvantageous in terms of securing rigidity when guiding a device such as a microcatheter. Therefore, even in the inner coil 50, the rigidity change is made stepwise to make these characteristics compatible.

The first flat portion 43 and the second flat portion 44 are portions formed by pressing a cylindrical portion continuous from the small diameter flexible portion 42. As shown in FIGS. 3 and 4, the first flat portion 43 is a tapered portion having a pair of inclined planes whose width increases from the small diameter flexible portion 42 toward the distal end side and whose height direction decreases. It is. The first flat portion 43 is connected to a second flat portion 44 that is a flat portion having a substantially rectangular cross section. The first flat portion 43 is rigid between the small-diameter flexible portion 42 and the second flat portion 44. In order to prevent the change from increasing and the stress from concentrating, it is provided to moderate the change in rigidity. In the present embodiment, the length of the first flat portion 43 in the axial direction is about 3.0 mm, and a sufficiently gradual change in rigidity can be obtained.

As shown in FIGS. 3 and 4, the second flat portion 44 is a substantially rectangular plate-like portion, and has two pairs of planes substantially parallel to the axis of the core shaft 14. The length of the second flat portion 44 in the axial direction is set to be substantially the same as the length of the first flat portion 43 in the axial direction, and is about 3.0 mm in the present embodiment. As shown in FIG. 4, the width of the second flat portion 44 widened in a flat shape has a predetermined gap between the side surface of the second flat portion 44 and the inner peripheral surface of the inner coil 50. However, the side surface may be in contact with the inner peripheral surface of the inner coil 50.
In addition, since the 2nd flat part 44 is shape | molded by press work, the side surface of the 2nd flat part 44 is not a plane strictly, but is circular arc shape. Therefore, the section of the second flat portion 44 having a substantially rectangular shape includes such a shape that the side surface is an arc.

The total axial length of the first flat portion 43 and the second flat portion 44 is preferably set in the range of about 2.0 mm to about 10.0 mm. Among these, it is preferable that the 2nd flat part 44 which comprises the most flexible part of the core shaft 14 occupies about 1.0 mm or more.
The flat portion composed of the first flat portion 43 and the second flat portion 44 not only makes the tip of the guide wire 10 flexible, but also increases the torsional rigidity and provides a tip portion of the guide wire 10 called shaping. Although it is used for bending and directing, if this flat portion becomes shorter than about 2.0 mm, shaping becomes difficult.
A microcatheter into which the guide wire 10 is inserted is often bent at a portion of about 8.0 mm from the distal end of the catheter, but the first flat portion 43 and the second flat portion 44 in the axial direction are often used. If the total length is longer than about 10.0 mm, a flat portion may exist beyond the bent portion of the catheter. In such a state, the rotational force is applied from the rear end side of the guide wire 10. When given, the tip of the guide wire 10 is fixed at the tip of the bent portion of the microcatheter, and a torsional stress acts on this portion. Further, when a rotational force is further applied and the stress exceeds a certain amount, a phenomenon called so-called bouncing, in which the tip of the guide wire 10 suddenly moves greatly in the rotational direction and the torsional stress is released, is likely to occur. There is sex.

Most of the fourth tapered portion 35 of the most distal portion 40 and the tip portion 30 is inserted into the inner coil 50. The inner coil 50 is a hollow coil manufactured by twisting a plurality of metal strands 51 on a core bar, removing residual stress when twisted by a known heat treatment, and extracting the core bar. It is a stranded wire coil. The outer diameter of the inner coil 50 is about 0.19 mm in the present embodiment. The length of the inner coil 50 in the axial direction is about 55.0 mm.
Six strands 51 are used for the inner coil 50. The diameter of the strand 51 is about 0.035 mm. The pitch of the inner coil 50 (the distance in the axial direction when the spiral formed by one strand makes one round) is set to be in the range of about 0.25 to about 0.29 mm. The number and diameter of the strands 51 are appropriately determined in consideration of the outer diameter and rigidity required for the inner coil 50, and are not limited to these values.
Although the material of the strand 51 is not specifically limited, In the case of this Embodiment, stainless steel is used. As a material other than this, a superelastic alloy such as a Ni-Ti alloy is used. Moreover, you may combine the strand of a different material.

The tip of the inner coil 50 is joined to the tip of the core shaft 14 by brazing together with the tip of the outer coil 60 with the axis of the core shaft 14 as the center, and the brazed portion has a substantially hemispherical tip 15 ( Tip joint). The rear end of the inner coil 50 is joined to the fourth tapered portion 35 of the front end portion 30 by brazing to form an inner rear end joint portion 52.
The inner coil 50 surrounds most of the fourth taper portion 35 of the core shaft 14, and the third taper portion 34 (intermediate taper portion) where the inner coil 50 does not exist and the fourth taper where the inner coil 50 exists. The inclination angle of the taper changes with the portion 35 (tip tapered portion). This is because the rigidity of the inner coil 50 is changed by changing the inclination of the fourth taper portion 35 of the core shaft 14 in order to prevent the rigidity of the guide wire 10 from changing abruptly due to the arrangement of the inner coil 50. This is to offset the increase in the amount as much as possible.

That is, the third taper portion 34 has a larger diameter change rate by increasing the taper angle with respect to the axis of the core shaft 14 than the fourth taper portion 35, and the rigidity change amount by not having the inner coil 50. Is offset.
Further, the inner rear end joint portion 52 of the inner coil 50 is joined only to the core shaft 14 and is not joined to an outer intermediate joint portion 65 or the like of the outer coil 60 to be described later. Can be made small. For this reason, the rigidity change of the core shaft 14 by brazing can be reduced as much as possible.
In addition, by connecting another taper portion having a different taper angle between the third taper portion 34 and the fourth taper portion 35, both are connected, and the diameter and the wire diameter of the outer coil 60 change. Thus, when the rigidity of the outer coil 60 changes, the taper angle of the third taper portion 34 having the outer intermediate joint portion 65 is smaller than the taper angle of the fourth taper portion 35 having the inner coil 50. By doing so, there is a case where the change in rigidity is adjusted.

Most of the first small diameter portion 32 from the most distal end portion 40 including the inner coil 50 to the distal end portion 30 is inserted into the outer coil 60. The outer coil 60 is obtained by winding a single metal wire 61. In the present embodiment, the outer diameter of the outer coil 60 is about 0.36 mm, and the axial length of the outer coil 60 is about 300.0 mm.
The strand 61 of the outer coil 60 is formed by joining a radiopaque metal wire such as a platinum alloy and a radiolucent metal wire such as stainless steel into one strand. In the case of this embodiment, the diameter is about 0.065 mm. Therefore, in the present embodiment, a gap of about 0.02 mm is provided between the inner peripheral surface of the outer coil 60 and the outer peripheral surface of the inner coil 50 in the radial direction.
Since the outer coil 60 is formed of one strand, the pitch of the outer coils 60 can be approximately approximate to the strand diameter and is about 0.065 mm. On the other hand, as described above, since the pitch of the inner coil 50 is set to be in the range of about 0.25 to about 0.29 mm, adjacent elements in the six strands constituting the inner coil 50 are set. The average distance of the lines will be in the range of about 0.042 to about 0.048 mm. Accordingly, the average distance between adjacent wires of the inner coil 50 is set to be smaller than the average distance between adjacent wires of the outer coil 60.
As described above, the inner coil 50 and the outer coil 60 are independent from each other with a gap, and the average distance between adjacent wires of the inner coil 50 is set smaller than the average distance between adjacent wires of the outer coil 60. By doing so, the double coil structure of the inner coil 50 and the outer coil 60 is easily bent and has a flexible structure.

A portion made of a radiopaque metal wire of the outer coil 60 is a portion of about 50.0 mm from the tip of the outer coil 60 and constitutes an opaque portion 62 that functions as a marker. A portion of the impermeable portion 62 that is approximately 30.0 mm from the distal end of the outer coil 60 is a loosely wound portion 62a that is wound loosely so that a gap is formed between the strands 61. The portion closer to the base end is a densely wound portion 62b wound in a tightly wound manner so that there is no gap between the strands 61 and the strands 61 are in contact with each other. The gap between the strands 61 in the loosely wound portion 62a is about 0.01 to about 0.02 mm.
The portion made of the radiolucent metal wire occupies the portion of the outer coil 60 on the rear end side from the non-transmissive portion 62, and the transmissive portion 63 wound in close winding so that the strands 61 are in contact with each other. It has become.

The loosely wound portion 62a of the outer coil 60 also contributes to facilitating shaping of the distal end portion of the guide wire 10. That is, the double-coil structure of the inner coil 50 and the outer coil 60 gives an impression that it is difficult to shape the operator because the coils interfere with each other rather than the configuration of only the outer coil and the core shaft when shaping. Although there is a possibility, by providing a gap in the strand 61 of the outer coil 60, it is possible to make the configuration easy to shape.
For this reason, the most distal end portion 14 of the core shaft 14 is located in the loosely wound portion 62a. It is preferable that the small-diameter flexible portion 42, the first flat portion 43, and the second flat portion 44 that are highly likely to be shaped in the most advanced portion 14 are located in the loosely wound portion 62a.

The tip of the outer coil 60 is joined to the tip of the core shaft 14 by brazing at the tip tip 15 coaxially with the inner coil 50. The rear end of the outer coil 60 is joined to the first small diameter portion 32 of the tip portion 30 by brazing to form an outer rear end joint portion 64.
Further, the outer coil 60 is joined to the third taper portion 34 of the distal end portion 30 by brazing to form an outer intermediate joint portion 65.

The outer coil 60 and the inner coil 50 are joined by brazing at the coil joint 53. The coil joint portion 53 joins only the outer coil 60 and the inner coil 50, and the brazed solder does not reach the core shaft 14 and is not joined to the core shaft 14.
The coil joint portion 53 is on the rear end side of the loosely wound portion 62a in which the strand 61 of the non-transparent portion 62 of the outer coil 60 is wound in a loosely wound manner, and the densely wound portion in which the strand 61 is wound in a tightly wound manner. It arrange | positions in the approximate center of the winding part 62b. The reason is to prevent the rigidity of the guide wire 10 from changing abruptly by the coil joint portion 53 as much as possible. That is, in the outer coil 60, the opaque portion 62 made of a radiopaque metal wire such as platinum alloy is compared with the transparent portion 63 made of a radiolucent metal wire such as stainless steel. The rigidity is low due to the difference in material. Further, with the same material, the loosely wound portion 62a having a gap between the strands 61 has lower rigidity than the densely wound portion 62b. For this reason, the rigidity of the loosely wound portion 62a is the lowest and flexible, and then the densely wound portion 62b has the lowest rigidity, and the transmissive portion 63 in which the radiation-transmitting strand 61 is wound in a tightly wound manner is the highest. . When the boundary between the portions 62a, 62b, and 63 where the rigidity change occurs overlaps with the coil joint portion 53, the rigidity change is more emphasized. Therefore, in order to prevent this as much as possible, the above arrangement is used. It has been adopted.
Similarly, the inner rear end joint portion 52 of the inner coil 50 is also arranged so as to be biased toward the rear end side from the non-permeable portion 62 of the outer coil 60 so as not to overlap with the boundary between 62a, 62b, and 63 where the rigidity change occurs. ing.

  Further, since the densely wound portion 62b and the transmissive portion 63 of the non-permeable portion 62, which are located on the rear end side of the coil joint portion 53, both have the wire 61 densely wound, the rotational torque on the proximal end side of the guide wire 10 Is transmitted not only from the core wire 14 but also from the outer coil 60 to the inner coil 50 via the coil joint portion 53, the transmission of rotational torque is prevented from being impaired by the gap between the strands 61.

  Further, the inner rear end joint portion 52 of the inner coil 50 is spaced apart from the outer intermediate joint portion 65 of the outer coil 60 in the axial direction to form a space 67. If the inner coil 50 and the outer coil 60 are joined to the core shaft 14 at the same position, the rigidity of the guide wire 10 is increased at that position, and the rigidity of the guide wire 10 is rapidly changed. This is to prevent as much as possible. By separately joining the rear end of the inner coil 50 and the middle part of the outer coil 60, brazing brazing used for joining can be reduced, so that the influence on the rigidity change of the core shaft 14 is minimized. Can be suppressed. Therefore, with this configuration, it is possible to improve transmission of rotational force and pushing force applied from the proximal side of the guide wire 10.

In the graph shown in FIG. 5, the above-described guidewire 10 shown in FIGS. 1 to 4 and a test guidewire for comparison were produced, and the rotational followability of the guidewire was measured by the measuring device 80 shown in FIG. Is. That is, the rotation angle on the distal end side when the rear end side of the guide wire is rotated is measured.
The measuring device 80 is assumed to be a microcatheter used at the same time as the guide wire 10 of the present embodiment, and includes a resin tube 81 having a lumen inside. The tube 81 has a first curved portion 81a having a curvature radius of 60.0 mm on the rear end side and a second curved portion 81b having a curvature radius of 10.0 mm on the distal end side. A guide wire made for testing, such as the guide wire 10, is inserted into the measuring device 80 having this configuration, and the rear end side is rotated clockwise by a predetermined angle [degree] by 180 degrees. The rotation angle [degree] is measured.

  In FIG. 5, a graph L0 indicated by a solid line indicates an ideal line in which the rear end side and the front end side of the guide wire rotate 1: 1. A graph L1 indicated by a white square is that of the guide wire 10 of the present embodiment. A graph L2 indicated by a broken line is that of the first comparison guide wire without the inner coil 50 in the guide wire 10 of the present embodiment. A graph L3 indicated by a white circle is that of the second comparative guide wire that does not have only the coil joint portion 53 that joins the outer coil 60 and the inner coil 50 in the guide wire 10 of the present embodiment.

The guide wire 10 of the present embodiment is intended to be used for blood vessels in the brain, for example. As a result of investigation by the inventors of the present application, when used for such a purpose, the guide wire is 0 to 90. In many cases, the rotation operation is performed in the vicinity of the degree, and it has been found that the rotation followability in this range is particularly important. For example, in the case of the brain, when a guide wire enters the target aneurysm, the rotation operation is highly accurate in the range of 0 to 90 degrees in order to direct the tip of the guide wire to the entrance of the aneurysm. Is required.
In FIG. 5, the graph L2 of the first comparison guide wire without the inner coil 50 deviates significantly from the ideal graph L0 not only in the range of 0 to 90 degrees but also in the range up to 180 degrees.
Although the graph L3 of the second comparison guide wire having the inner coil 50 but not having the coil joint portion 53 has the inner coil 50, the rotational followability is improved as compared with the first comparison guide wire. , Deviating from the ideal graph L0 in the range of 0 to 90 degrees. That is, when the operator rotates the rear end side of the guide wire, rotation is transmitted by the inner coil 50, but the front end side does not rotate immediately. It is necessary to apply an extra amount of rotation, indicating that the operability is poor.
On the other hand, the graph L1 of the guide wire 10 of this embodiment is ideal in the range of 0 to 90 degrees, although the rotational followability is slightly inferior to that of the second comparative guide wire in the range after about 135 degrees. It can be seen that the rotation followability close to the graph L0 is shown. That is, when the operator rotates the rear end side of the guide wire, the front end side rotates immediately, indicating that the operability is good. This is because the rotation of the rear end side of the guide wire 10 is transmitted not only from the core shaft 14 but also from the outer coil 60 to the inner coil 50 via the coil joint portion 53, so that the rotational followability of the inner coil 50 is improved. It is thought that.

The graphs shown in FIGS. 7 and 8 are produced by producing comparative guidewires A and B which are different from the above-described guidewire 10 shown in FIGS. 1 to 4 and the above-described experiment of FIG. The comparison experiment was conducted about the characteristic which maintains the shape of the shaping of the guide wire 10, and the restorability.
The comparison guide wire A has a configuration in which the inner coil 50 is simply removed from the configuration of the guide wire 10 of the present embodiment. For this reason, the comparison guide wire A is less rigid than the guide wire 10 of the present embodiment.
The comparison guide wire B does not include the inner coil 50, but the rigidity in the range of about 5 to 20 mm of the distal end of the guide wire, which is important for the guide wire to guide the microcatheter or the like, is substantially the same value as the guide wire 10; It was created to have substantially the same stiffness curve. In order to realize such rigidity, the comparison guide wire B has a diameter corresponding to 1.2 mm compared to the diameters of the large diameter flexible portion 41 and the small diameter flexible portion 42 of the guide wire 10. % Is set to be large.

FIG. 7 compares the characteristics of maintaining the shape during shaping using the guide wire 10 of this embodiment and the comparative guide wires A and B. FIG. The shaping is normally performed in the range from the second flat portion 44 to the fourth taper portion 35 where the inner coil 50 is provided, but in this experiment, a highly probable portion is assumed empirically. Then, a portion of about 8 mm from the tip of each guide wire (corresponding to the small diameter flexible portion 42) was bent at about 70 °. Then, these guide wires were inserted into a resin tube having an inner diameter of 0.5 mm, extracted from the tube after 10 rotations in the tube, and further extracted from the tube after 10 rotations and a total of 20 rotations. The angle deformation rate was measured. FIG. 7 shows an average of measured values obtained by performing such an experiment a plurality of times.
The inner diameter of the resin tube is set to be narrower than the blood vessel assumed when the guide wire 10 of the present embodiment is used so that the difference in comparison becomes clear.

  Although the comparison guide wire A does not have the inner coil 50, the same core shaft 14 as that of the guide wire 10 of the present embodiment is used, so that the distal end portion 40 is reduced in diameter. For this reason, at 10 rotations, a big difference compared with the guide wire 10 is not seen. However, in the case of 20 rotations, the deformation rate of the shaped shape is large. That is, it shows that the shape angle has changed since the shaping angle does not return while being expanded in the resin tube as compared with the guide wire 10 of the present embodiment. Therefore, it can be seen that the inner coil 50 not only improves the rotation followability described above but also improves the performance of maintaining the shape of the shaping.

  The comparison guide wire B is formed so as to have substantially the same rigidity curve in the range of about 5 to 20 mm from the tip of the guide wire 10 of the present embodiment, although it does not have the inner coil 50. is there. For this reason, the shaft is thicker than the guide wire 10 of the present embodiment. As a result, the deformation rate of the shaped shape is larger than that of the guide wire 10 in both cases of 10 rotations and 20 rotations. That is, the comparative guide wire B having substantially the same rigidity change as the guide wire 10 has sufficient rigidity for guiding the microcatheter, but when a rotational force is applied in the blood vessel, the angle of shaping changes easily. You can see that Therefore, it can be seen that the guide wire 10 of the present embodiment has improved performance for maintaining the shape of the shaping while securing rigidity for guiding the microcatheter.

  FIG. 8 is a comparison of restoration performance using the guide wire 10 of this embodiment and the guide wires A and B for comparison. In this experiment, each guide wire that was not shaped was inserted into a resin tube having a radius of 5.0 mm and curved at 180 ° and having an inner diameter of 0.5 mm, and then the amount of deformation at the tip was measured when the guide wire was pulled out. . The pulling speed when the guide wire was pulled out was about 600 mm / min. In addition, the guide wire 10 is installed so that a range of about 55 mm from the distal end of the guide wire that is likely to be bent, that is, a range where the inner coil 50 exists in the guide wire 10 completely passes through the curved portion of the tube. Later, the guide wire was pulled out and the amount of deformation at the tip was measured. The amount of deformation at the distal end is measured by measuring the linear distance from the axis of the guide wire shaft that extends substantially straight to the tip of the curved guide wire when the guide wire after being pulled out is placed in a natural state. . FIG. 8 shows an average of measured values obtained by performing such an experiment a plurality of times.

Although the comparison guide wire A does not have the inner coil 50, the same core shaft 14 as the guide wire 10 of the present embodiment is used. I couldn't. That is, there was no significant difference in recoverability.
On the other hand, the comparison guide wire B has a large amount of deformation at the distal end portion compared to the guide wire 10, indicating that the restoration property is poor. That is, the comparison guide wire B, which has substantially the same change in rigidity as the guide wire 10, has sufficient rigidity for guiding the microcatheter, but easily deforms when an external force is applied in the bent blood vessel. It turns out that it is difficult to restore.
Therefore, the guide wire 10 according to the present embodiment is provided with the inner coil 50, so that the performance of maintaining the shape of the shaping is improved while ensuring the rigidity for guiding the microcatheter. I understand.

From the experimental results of FIGS. 7 and 8, the guide wire 10 of the present embodiment is
Since the tip portion of the core shaft 14 can be reduced in diameter, while maintaining the rigidity for guiding the microcatheter, the performance of maintaining the shape when shaping is improved, and the resilience is improved. That is, the angle of the part that is once bent after being shaped is maintained, and the part that is not shaped can be prevented from being bent by an external force during the procedure.

  Based on the above configuration, the operation when the guide wire 10 of the present embodiment is used for a brain procedure will be described with reference to FIG.

The guide wire 10 passes through the neck by being inserted into the artery from the thigh or the like, and reaches the aneurysm 300 which is a target treatment site in the artery 301 in the brain. In this process, the guide wire 10 is used in combination with the microcatheter 200. At this time, after advancing a predetermined distance from a state in which the tip of the guide wire 10 is slightly protruded from the tip of the microcatheter 200, the microcatheter 200 is advanced so as to follow this, and the tip of the microcatheter 200 is moved to the guide wire. When the vicinity of the tip of 10 is reached, the guide wire 10 is again moved forward by a predetermined distance, and both are brought close to the target position.
At this time, the predetermined portion on the distal end side of the guide wire 10 is in contact with the wall surface of the blood vessel, but has a double coil structure composed of the inner coil 50 and the outer coil 60. Contact and damage to the blood vessel can be prevented as much as possible.

That is, the outer coil 60 and the inner coil 50 are only connected by the coil joint portion 53, and a gap is provided between them, so that they are independent. There is no loss.
In particular, since the inner coil 50 is a stranded coil composed of a plurality of strands 51, the inner coil 50 has not only high rotation followability but also flexibility. In the guide wire 10, the inner coil 50 is joined only to the outer coil 60 by the coil joining portion 53 except that both ends are joined to the core shaft 14, and is joined to the core shaft 14 in the intermediate portion of the inner coil 50. Not. With such a structure, it is possible to prevent the flexibility of the inner coil 50 from being lost as much as possible. Therefore, it is possible to maintain safety while improving the rotational followability that is a characteristic of the stranded coil.

  Further, the guide wire 10 has not only a change in the rigidity of the core shaft 14 due to the provision of the inner coil 50, but also a portion 62a whose rigidity changes depending on the material constituting the outer coil 60, a densely wound coil or a loosely wound coil. Considering the boundary between 62b and 63 and the positional relationship between the inner rear end joint 52 and the coil joint 53 of the inner coil 50, the structure prevents the sudden change of rigidity as much as possible. For this reason, while having high rotation followability, the pushing characteristic which is the ease of insertion when pushing the guide wire 10 into the body in the axial direction is also improved. That is, since the rigidity does not change abruptly, when the guide wire 10 is operated on the rear end side and torque is applied, torque transmission is stagnated at the rigidity changing portion, and the operability is deteriorated. Can be prevented as much as possible.

  As schematically shown in FIG. 9, when the tip of the guide wire 10 is positioned in the vicinity of the aneurysm 300 in the brain, which is the target site, the tip of the microcatheter 200 is moved into the aneurysm 300 to enter the artery. An operation of inserting the tip of the guide wire 10 toward the inside of the knob 300 is performed. Usually, the distal end portion of the guide wire 10 is angled by an operation called shaping in which a portion of the distal end portion of the guide wire 10 is bent to form an angle, and this angled portion is attached to the aneurysm 300. The entrance 310 is rotated in a certain direction and inserted. In this shaping, a force is applied from a direction perpendicular to the planes of the first flat portion 43 and the second flat portion 44 and the angle is given by bending. The portion to be bent varies depending on the procedure, but is usually in the range from the second flat portion 44 to the fourth tapered portion 35 where the inner coil 50 is provided.

  In particular, since the most advanced portion 40, which is a highly probable portion where shaping is performed, is located in the loosely wound portion 62 a of the outer coil 60, the loosely wound portion even in the double coil structure of the outer coil 60 and the inner coil 50. Shaping can be easily performed by the gap between the strands 61 provided in 62a.

  Until the guide wire 10 is positioned in the vicinity of the aneurysm 300, the outer diameter of the distal end portion of the guide wire 10 can ensure the rigidity by the inner coil 50, so that the microcatheter 200 can be guided well. Moreover, as is apparent from the characteristics shown in FIG. 7, the angle of shaping applied to the distal end of the guide wire 10 changes even if it passes through a narrow blood vessel up to the aneurysm 300. Is prevented as much as possible. In addition, since the restoring property is improved as shown in FIG. 8, even if it passes through a bent narrow blood vessel, the distal end portion of the guide wire 10 can be prevented from being bent as much as possible.

  The operation of orienting the distal end of the guide wire 10 toward the entrance 310 of the aneurysm 300 and inserting the distal end of the guide wire 10 into the aneurysm 300 is carefully performed, but from the characteristics shown in FIG. As is clear, since the guide wire 10 of the present embodiment exhibits high rotational followability in the range of 0 to 90 degrees, a delicate rotation operation on the rear end side of the guide wire 10 by this technique is effective. Therefore, the procedure can be easily realized. This is because the rotational torque from the outer coil 60 can be effectively transmitted to the inner coil 50 by joining the outer coil 60 and the inner coil 50 by the coil joint portion 53. In addition, this effect is further enhanced by making all the strands 61 of the outer coil 60 closer to the base end side than the coil joint portion 53 tightly wound.

In this way, by rotating the distal end portion of the guide wire 10 and directing the distal end of the guide wire 10 in a desired direction, the micro catheter 200 is pushed along the guide wire 10 to thereby move the distal end portion of the micro catheter 200. To change. At this time, since the first flat portion 43 and the second flat portion 44 are provided at the most distal portion 40 of the guide wire 10 and the torsional rigidity is increased, the direction of the distal end portion of the microcatheter 200 is changed. Can be easily realized. In addition, since the first flat portion 43 for moderately changing the rigidity is provided on the rear end side of the second flat portion 44, in order to change the direction of the microcatheter 200, the guide wire 10 Even if a large load is applied to the tip portion, it is possible to prevent the leading edge portion 40 of the core shaft 14 from being bent or broken as much as possible.
Further, since the most distal portion 40 of the core shaft 14 is surrounded by the inner coil 50, the inner coil 50 can receive a load acting on the most distal portion 40 of the core shaft 14. It is possible to further prevent the distal end portion 40 from being bent or broken.

  As described above, the microcatheter 200 is made to reach the target site along the guide wire 10. Thereafter, the guide wire 10 is removed from the body, and treatment with the microcatheter 200 is performed.

  In the embodiment described above, the case where the guide wire 10 is used for the brain has been described. However, the guide wire 10 can also be used for a heart or other organs other than the brain.

Further, the taper portion constituting the distal end portion 30 and the most distal end portion 40 of the guide wire 10, the number of cylindrical portions having a constant outer diameter, the outer diameter, the length in the axial direction, and the like are appropriately changed depending on the desired rigidity. Can do.
Moreover, the shape of the most advanced part 40 can also take various shapes. For example, various shapes such as a combination of columnar shapes having a constant outer diameter or a shape having a plurality of plate-like flat portions having a substantially rectangular cross-sectional shape and decreasing in thickness toward the tip can be taken.

10 Guide wire 14 Core shaft 15 Tip (tip joint)
30 Tip 34 Third taper (intermediate taper)
35 4th taper part (tip taper part)
40 Most advanced part 41 Large diameter flexible part 42 Small diameter flexible part 43 First flat part 44 Second flat part 50 Inner coil 51 Wire 52 Inner rear end joint part 53 Coil joint part 60 Outer coil 61 Wire 62 Impermeable part 62a Loosely wound portion 62b Closely wound portion 63 Transparent portion 64 Outer rear end joint portion 65 Outer intermediate joint portion

Claims (9)

A core shaft;
An inner coil formed by twisting a plurality of strands and surrounding a tip side portion of the core shaft;
At least one strand is wound, and the loosely wound portion is wound so that the strands are separated from each other on the front end side, and the strand is wound so that the strands are in contact with each other on the rear end side. An outer coil that surrounds the inner coil and the tip side of the core shaft,
A tip joint for joining the tip of the outer coil and the tip of the inner coil to the tip of the core shaft;
An outer rear end joint for joining the rear end of the outer coil to the core shaft;
An inner rear end joint that joins the rear end of the inner coil only to the core shaft on the rear end side of the outer coil and on the front end side of the outer rear end joint. A guide wire characterized by that. The outer coil is made of a wire of a radiopaque material on the tip side, and at least a part on the tip side is the sparsely wound portion,
The rear end side is made of an elemental wire made of a radiolucent material, and has a transmission part consisting only of the densely wound part,
The guide wire according to claim 1, wherein the inner rear end joint portion of the inner coil is located on the rear end side with respect to the impermeable portion. The outer coil has an outer intermediate joint that joins the outer coil to the core shaft between the tip joint and the outer rear joint.
3. The guide wire according to claim 1, wherein the inner rear end joint portion of the inner coil is located on a distal end side with respect to the outer intermediate joint portion. The outer intermediate joint portion of the outer coil is located at an intermediate taper portion where the core shaft becomes thinner toward the tip side,
The inner rear end joint portion of the inner coil is located at a tip side taper portion where the core shaft becomes narrower toward the tip side on the tip side than the intermediate taper portion,
The guide wire according to claim 3, wherein an inclination angle of the intermediate taper portion is different from an inclination angle of the tip side taper portion. 5. The coil joint for joining only the outer coil and the inner coil to each other is provided between the tip joint and the inner rear end joint of the inner coil. Or a guide wire according to claim 1. The guide wire according to claim 5, wherein the outer coils are closely wound so that the strands come into contact with each other on the rear end side of the coil joint portion. The tip side portion of the core shaft surrounded by the inner coil has at least two cylindrical portions having different diameters, a large diameter flexible portion and a small diameter flexible portion having a smaller diameter than the large diameter flexible portion. The guide wire according to any one of claims 1 to 6, wherein: The guide wire according to claim 7, wherein the small diameter flexible portion is disposed at a position corresponding to the loosely wound portion of the outer coil. The guide wire according to any one of claims 1 to 8, wherein a flat portion having at least two flat portions facing each other is provided at a tip end of the core shaft.