JP7256582B2 - guide wire - Google Patents

Description

The technology disclosed in this specification relates to a guidewire inserted into a blood vessel or the like.

BACKGROUND ART A method using a catheter is widely used as a method for treating or examining narrowed or blocked portions (hereinafter referred to as "lesions") in blood vessels or the like. A guide wire is generally used to guide a catheter to a lesion in a blood vessel or the like. The guidewire includes a core shaft, a coil body arranged so as to surround the outer circumference of the core shaft, and a joint (distal tip) that joins the distal end of the core shaft and the distal end of the coil body.

Conventionally, a guide wire is known in which radiopaque metal powder is introduced into the inner space of the coil body (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2001-286568

When using a guidewire, the distal end of the guidewire is intentionally bent into a U-shape (hereinafter referred to as "prolapse") in order to improve the ability to pass through lesions in blood vessels. I have something to do. A prolapse is formed starting from a stiffness change point (for example, a point where the diameter changes) in the core shaft. With conventional guidewires, when the guidewire is inserted after the prolapse is formed, the prolapse progresses further (the starting point of the prolapse moves toward the proximal end, and the ratio of the length of the bent portion to the total length increases. )Sometimes. After the prolapse is formed, if the prolapse progresses further along with the operation of inserting the guide wire, problems such as damage to the vascular wall may occur, which is not preferable. Even if radiopaque metal powder is introduced into the inner space of the coil body like the guide wire disclosed in the above-mentioned Patent Literature 1, it is not possible to suppress the further progress of the prolapse after prolapse formation.

This specification discloses a technology capable of solving the above-described problems.

The technology disclosed in this specification can be implemented, for example, in the following forms.

(1) The guidewire disclosed in the present specification is a guidewire comprising a core shaft, a bag body formed apart from the tip of the core shaft, and a dilatant fluid enclosed in the bag body. , provided.

In this guidewire, a dilatant fluid is sealed in a pouch formed apart from the distal end of the core shaft. A dilatant fluid is a fluid that hardens when subjected to a relatively fast shear stimulus, but does not harden when subjected to a relatively slow shear stimulus. Therefore, a prolapse can be formed on the distal end side of the guidewire in the same manner as in the conventional art by operating the dilatant fluid so as not to generate a relatively fast shearing stimulus. Further, when the guide wire is inserted after the prolapse is formed, a relatively fast shearing stimulus acts on the dilatant fluid and hardens the dilatant fluid along with the insertion operation. Therefore, the hardened dilatant fluid suppresses deformation of the core shaft in the vicinity of the distal end, thereby suppressing the prolapse from progressing any further. Therefore, according to the present guidewire, it is possible to suppress the further progress of the prolapse after the prolapse formation, and to suppress the occurrence of problems (for example, damage to the vascular wall) associated with the further progress of the prolapse.

(2) In the above guidewire, the core shaft has a first portion and a second portion adjacent to the proximal end side of the first portion, and the bag is a portion of the core shaft. It may be configured to accommodate a boundary between the first portion and the second portion. According to the present guidewire, compared to a configuration in which the rigidity is different by, for example, using different materials for the first portion and the second portion, the manufacturing of the core shaft is facilitated, and thus the guidewire is easily manufactured. can be realized.

(3) In the above guidewire, the second portion of the core shaft is a tapered portion whose diameter gradually increases from the proximal end of the first portion toward the proximal end side of the guidewire. , the guide wire further includes a ring-shaped fixing member disposed so as to surround the outer periphery of the second portion of the core shaft, and a proximal end of the bag between the second portion and the second portion. It is good also as a structure provided with the fixing member which seals the said bag body by clamping. According to this guidewire, since the ring-shaped fixing member that seals the proximal end of the bag body is arranged in the second portion, which is the tapered portion of the core shaft, the fixing member is placed on the proximal end side. It is possible to suppress the displacement of the fixing member, thereby preventing the deterioration of the above-described prolapse suppression effect due to the displacement of the fixing member.

It should be noted that the technology disclosed in this specification can be implemented in various forms, for example, in the form of a guide wire, a manufacturing method thereof, and the like.

Explanatory drawing schematically showing the configuration of the guide wire 100 in the present embodiment. Explanatory drawing schematically showing the configuration of the guide wire 100 in the present embodiment. Explanatory drawing showing a state in which a prolapse is formed at the distal end of the guide wire 100

A. Embodiment:
A-1. Basic configuration of the guidewire 100:
1 and 2 are explanatory diagrams schematically showing the configuration of the guidewire 100 in this embodiment. FIG. 1 shows the configuration of a side section (YZ section) of the guidewire 100, and FIG. 2 shows the configuration of the section (XY section) of the guidewire 100 at the position II-II in FIG. It is In FIG. 1, the Z-axis positive direction side is the tip side (distal side) inserted into the body, and the Z-axis negative direction side is the proximal side (proximal side) operated by an operator such as a doctor. . Although FIG. 1 shows the guide wire 100 as a whole in a straight line substantially parallel to the Z-axis direction, the guide wire 100 has flexibility to the extent that it can be curved.

A guide wire 100 is a medical device inserted into a blood vessel or the like in order to guide a catheter to a lesion (stenosis or occlusion) in the blood vessel or the like. The guidewire 100 includes a core shaft 10 , a coil body 20 , a distal joint portion 31 and a proximal joint portion 32 .

The core shaft 10 is a rod-shaped member having a small diameter on the distal end side and a large diameter on the proximal end side. More specifically, the core shaft 10 includes a rod-shaped small diameter portion 11 with a circular cross section and a rod-shaped middle portion with a circular cross section located on the proximal side of the small diameter portion 11 and having a larger diameter than the small diameter portion 11 . Between the diameter portion 13, a rod-shaped large diameter portion 15 having a circular cross section located on the proximal side of the intermediate diameter portion 13 and having a diameter larger than that of the intermediate diameter portion 13, and the small diameter portion 11 and the intermediate diameter portion 13 between the first tapered portion 12 whose diameter gradually increases from the boundary position with the small-diameter portion 11 toward the boundary position with the intermediate-diameter portion 13, and the intermediate-diameter portion 13 and the large-diameter portion 15. and a second tapered portion 14 whose diameter gradually increases from the boundary position with the intermediate diameter portion 13 toward the boundary position with the large diameter portion 15 . 1, illustration of a portion of the large-diameter portion 15 is omitted.

The core shaft 10 is made of, for example, metal materials, more specifically, stainless steel (SUS302, SUS304, SUS316, etc.), superelastic alloys such as Ni--Ti alloys, piano wires, nickel-chromium alloys, cobalt alloys, and tungsten. etc.

In this embodiment, the core shaft 10 is made of the same material over its entire length. Also, the first tapered portion 12 of the core shaft 10 has a larger diameter than the small diameter portion 11 . Therefore, it can be said that the first tapered portion 12 of the core shaft 10 has higher rigidity than the small diameter portion 11 . The narrow diameter portion 11 of the core shaft 10 corresponds to the first portion in the claims, and the first taper portion 12 corresponds to the second portion in the claims.

The coil body 20 is a coil-shaped member formed into a hollow cylindrical shape by spirally winding a wire. The coil body 20 is arranged so as to surround the outer periphery of the distal end portion of the core shaft 10 (in this embodiment, a portion of the narrow diameter portion 11, the first tapered portion 12, and the intermediate diameter portion 13 on the distal side). . In this embodiment, the coil body 20 has a structure in which one wire is loosely wound.

The coil body 20 is made of, for example, a metal material, more specifically, stainless steel (SUS302, SUS304, SUS316, etc.), superelastic alloys such as Ni—Ti alloys, piano wires, nickel-chromium alloys, or cobalt alloys. It is composed of radiolucent alloys or radiopaque alloys such as gold, platinum, tungsten, or alloys containing these elements (eg, platinum-nickel alloys). If the coil body 20 is made of a radiopaque material, the operator can grasp the position of the coil body 20 under the radioscopic image.

The distal end joint portion 31 is a member that joins the distal end 18 of the core shaft 10 and the distal end 21 of the coil body 20 . In other words, the distal end 18 of the core shaft 10 and the distal end 21 of the coil body 20 are fixed so as to be embedded inside the distal joint portion 31 . An outer peripheral surface of the distal end side of the distal end joint portion 31 is a smooth surface (for example, a substantially hemispherical surface). The tip side joint portion 31 corresponds to the joint portion in the claims.

The front end joint 31 is formed by, for example, brazing material (aluminum alloy brazing, silver brazing, gold brazing, etc.), metal solder (Ag—Sn alloy, Au—Sn alloy, etc.), adhesive (epoxy adhesive, etc.), or the like. It is configured.

The proximal joint portion 32 is a member that joins (the intermediate diameter portion 13 of) the core shaft 10 and the proximal end 22 of the coil body 20 . That is, the core shaft 10 and the proximal end 22 of the coil body 20 are fixed so as to be embedded in the proximal joint portion 32 .

Similar to the distal joint 31, the proximal joint 32 is made of, for example, brazing material (aluminum alloy brazing, silver brazing, gold brazing, etc.), metal solder (Ag--Sn alloy, Au--Sn alloy, etc.), adhesion It is composed of an agent (epoxy adhesive, etc.) or the like.

Part or all of the guidewire 100 may be coated with a known coating agent.

A-2. Detailed configuration of the guidewire 100:
Next, the detailed configuration of the guidewire 100 of this embodiment will be described. As shown in FIGS. 1 and 2, the guidewire 100 of this embodiment includes a bag 51. As shown in FIG. The bag body 51 is a bag-shaped member arranged in the inner space IS surrounded by the coil body 20 . The bag body 51 is arranged to accommodate at least the connecting portion 16 between the small diameter portion 11 and the first tapered portion 12 of the core shaft 10 . More specifically, the bag body 51 accommodates a portion of the small-diameter portion 11 on the proximal side and a portion of the first tapered portion 12 on the distal side. The bag 51 is made of a semipermeable membrane (for example, a cellophane membrane).

The guidewire 100 also includes a proximal side fixing member 52 and a distal side fixing member 53 that seal the bag body 51 . The proximal side fixing member 52 is a ring-shaped member arranged to surround the outer circumference of the first tapered portion 12 of the core shaft 10 . The base end side fixing member 52 seals the base end of the bag body 51 by sandwiching the base end of the bag body 51 with the first tapered portion 12 of the core shaft 10 . In addition, the base-end-side fixing member 52 is made of, for example, metal, and is crimped and fixed to the first tapered portion 12 of the core shaft 10 . Since the proximal side fixing member 52 is fixed to the first tapered portion 12, movement to the proximal side is restricted. The proximal side fixing member 52 corresponds to the fixing member in the claims.

Further, the distal end side fixing member 53 is a ring-shaped member arranged so as to surround the outer circumference of the small diameter portion 11 of the core shaft 10 . The distal end side fixing member 53 seals the distal end of the bag body 51 by sandwiching the distal end of the bag body 51 with the small diameter portion 11 of the core shaft 10 . The distal side fixing member 53 is made of metal, for example, and is crimped and fixed to the small diameter portion 11 of the core shaft 10 .

A dilatant fluid 55 is enclosed in the space within the bag 51 . Dilatant fluid 55 is a fluid that hardens when subjected to a relatively fast shear stimulus. As the dilatant fluid 55, for example, a mixture of a fine powder having a dilatancy characteristic made of an inorganic material (eg, Ni—Ti alloy) or a polymeric material and a liquid (eg, water) can be used. The fine powder that constitutes the dilatant fluid 55 has a particle size (for example, about 1 to 10 μm) that does not pass through the semipermeable membrane that is the constituent material of the bag 51, and the liquid that constitutes the dilatant fluid 55 is It passes through the semipermeable membrane. In addition, a fine powder having a dilatancy property is enclosed in the bag body 51, and when the guide wire 100 is inserted into the blood vessel, water in the blood permeates the bag body 51, which is a semipermeable membrane, and The body 51 may be filled with a dilatant fluid 55 .

In addition, the guide wire 100 of this embodiment can be manufactured as follows, for example. First, the core shaft 10 and the coil body 20 are prepared.
Next, the bag body 51 is prepared, and a part of the base end side of the small diameter portion 11 of the core shaft 10 and a part of the tip side of the first tapered portion 12 are accommodated in the bag body 51 . The bag body 51 is filled with a dilatant fluid 55 or a fine powder having dilatancy properties, and the proximal side fixing member 52 is crimped and fixed to the first tapered portion 12 of the core shaft 10, and the distal side fixing member 53 is fixed. The proximal end and the distal end of the bag body 51 are sealed by, for example, crimping and fixing to the small diameter portion 11 of the core shaft 10 . Next, with a portion of the distal end side of the core shaft 10 inserted into the inner space IS of the coil body 20, the distal joint portion 31 and the proximal end joint portion 31 for joining the core shaft 10 and the coil body 20 are joined by a known method. A side joint 32 is formed. The guide wire 100 having the configuration described above can be manufactured mainly by the above method.

A-3. Effect of this embodiment:
As described above, the guidewire 100 of this embodiment includes the core shaft 10, the coil body 20 arranged so as to surround the outer periphery of the core shaft 10, the distal end 18 of the core shaft 10, and the distal end 21 of the coil body 20. and a distal end side joint portion 31 that joins the . The core shaft 10 has a small-diameter portion 11 and a first tapered portion 12 adjacent to the small-diameter portion 11 on the proximal side and having higher rigidity than the small-diameter portion 11 . Further, the guidewire 100 of this embodiment includes a bag body 51 made of a semipermeable membrane. The bag body 51 is arranged in the inner space IS surrounded by the coil body 20 and accommodates at least the connecting portion 16 between the small diameter portion 11 and the first taper portion 12 of the core shaft 10 . A dilatant fluid 55 is enclosed in the bag body 51 .

Here, the connection point 16 between the small diameter portion 11 and the first tapered portion 12 of the core shaft 10 is a point of change in rigidity in the core shaft 10, and is a pro-lapse (the distal end of the guide wire 100 is intentionally U-shaped). This is the starting point for the bending. That is, as shown in FIG. 3 , starting from the connection point 16 of the core shaft 10 , the small diameter portion 11 located on the distal side of the connection point 16 is bent in a U-shape to form a prolapse. 3, illustration of a part of the configuration of the guide wire 100 (coil body 20, etc.) is omitted.

In the guide wire 100 of the present embodiment, a dilatant fluid 55 or a fine powder having dilatancy properties is enclosed in a bag body 51 that accommodates the connecting portion 16 between the small diameter portion 11 of the core shaft 10 and the first tapered portion 12. It is The dilatant fluid 55 is a fluid that hardens when subjected to a relatively fast shearing stimulus but does not harden when subjected to a relatively slow shearing stimulus. Therefore, by operating the dilatant fluid 55 so as not to generate a relatively fast shearing stimulus, a prolapse is formed starting from the connecting point 16 between the small diameter portion 11 and the first taper portion 12 as in the conventional art. can do. Further, when the guide wire 100 is inserted after forming the prolapse, a relatively fast shearing stimulus acts on the dilatant fluid 55 along with the insertion operation, and the dilatant fluid 55 hardens. Therefore, the hardened dilatant fluid 55 suppresses the deformation of the core shaft 10 in the vicinity of the connection point 16, thereby suppressing the prolapse from progressing any further. Therefore, according to the guidewire 100 of the present embodiment, it is possible to suppress the further progression of the prolapse after the prolapse formation, and to suppress the occurrence of problems (for example, damage to the vascular wall) associated with the further progression of the prolapse. can.

Further, in the guide wire 100 of the present embodiment, the first tapered portion 12 of the core shaft 10 is a portion having a larger diameter than the small diameter portion 11 of the core shaft 10 . Therefore, according to the guide wire 100 of the present embodiment, the manufacturing of the core shaft 10 is facilitated compared to, for example, a form in which the rigidity is varied by using different materials for the small diameter portion 11 and the first tapered portion 12. simplification of manufacturing of the guidewire 100 can be realized.

Further, in the guidewire 100 of the present embodiment, the first tapered portion 12 of the core shaft 10 has a tapered shape in which the diameter gradually increases from the proximal end of the small diameter portion 11 toward the proximal end side of the guidewire 100. part. Further, the guidewire 100 of the present embodiment further includes a ring-shaped proximal side fixing member 52 arranged so as to surround the outer circumference of the first tapered portion 12 of the core shaft 10 . The base end side fixing member 52 seals the bag body 51 by sandwiching the base end of the bag body 51 with the first tapered portion 12 of the core shaft 10 . As described above, in the guidewire 100 of the present embodiment, the ring-shaped proximal side fixing member 52 that seals the proximal end of the bag body 51 is arranged on the first tapered portion 12 of the core shaft 10 . , it is possible to suppress the proximal side fixing member 52 from being displaced to the proximal side, and to prevent the deterioration of the above-described prolapse suppression effect due to the positional displacement of the proximal side fixing member 52.

B. Variant:
The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the scope of the invention. For example, the following modifications are possible.

The configuration of the guide wire 100 in the above embodiment is merely an example, and various modifications are possible. For example, in the above embodiment, the coil body 20 has a structure in which the wires are loosely wound, but the coil body 20 may have a structure in which the wires are tightly wound. Further, in the above-described embodiment, the coil body 20 is formed in a hollow cylindrical shape by spirally winding one wire. It may be formed in a hollow cylindrical shape by winding it in a hollow cylindrical shape, or it may be formed in a hollow cylindrical shape by spirally winding a single twisted wire formed by twisting a plurality of strands. Alternatively, a plurality of stranded wires formed by twisting a plurality of strands may be spirally wound to form a hollow cylindrical shape.

In the above-described embodiment, the bag body 51 accommodates a portion of the narrow diameter portion 11 on the proximal end side and a portion of the first tapered portion 12 on the distal end side. Other portions of the core shaft 10 may be accommodated as long as the connecting portion 16 between the diameter portion 11 and the first tapered portion 12 is accommodated.

In the above embodiment, the core shaft 10 is composed of the small diameter portion 11, the first tapered portion 12, the intermediate diameter portion 13, the second tapered portion 14, and the large diameter portion 15. 10 may not have at least one of these five portions, or may have other portions in addition to the five portions. For example, instead of the small diameter portion 11, the core shaft 10 may include a rod-shaped first small diameter portion having a circular cross section, A rod-shaped second narrow diameter portion having a circular cross section with a larger diameter and a second narrow diameter portion located between the first narrow diameter portion and the second narrow diameter portion, and extending from the boundary position with the first narrow diameter portion to the second narrow diameter portion. and a tapered portion whose diameter gradually increases toward the boundary position with the small diameter portion. Also, the constituent materials of one portion of the core shaft 10 and the other portion may be different from each other.

Further, in the above embodiment, the point of change in rigidity of the core shaft 10, which is the starting point of the prolapse, is the connecting point 16 between the small-diameter portion 11 and the first tapered portion 12 having a larger diameter than the small-diameter portion 11. However, the rigidity change point is a connection point between a part of the core shaft 10 and another part made of a material (for example, stainless steel) having higher rigidity than the material (for example, Ni--Ti alloy) constituting the part. It may be In that case, the bag 51 containing the dilatant fluid 55 is arranged to contain the connection point.

In the above-described embodiment, the proximal side fixing member 52 is arranged so as to surround the outer circumference of the first tapered portion 12 of the core shaft 10, but the proximal side fixing member 52 is arranged at another position (for example, the core (position surrounding the outer circumference of the small-diameter portion 11 of the shaft 10).

In addition, the material of each member in the above embodiment is merely an example, and various modifications are possible. Moreover, the manufacturing method of the guide wire 100 in the above-described embodiment is merely an example, and various modifications are possible.

10: Core shaft 11: Small diameter part 12: First tapered part 13: Intermediate diameter part 14: Second tapered part 15: Large diameter part 16: Connection part 18: Tip 20: Coil body 21: Tip 22: Base End 31: Distal side joint part 32: Proximal side joint part 51: Bag body 52: Proximal side fixing member 53: Distal side fixing member 55: Dilatant fluid 100: Guide wire IS: Inner space

Claims (3)

a guide wire,
a core shaft;
a bag that is spaced apart from the tip of the core shaft and accommodates a rigidity change point of the core shaft ;
a dilatant fluid enclosed within the bag;
A guidewire. The guidewire of claim 1, comprising:
The core shaft is adjacent to a first portion and a proximal end of the first portion, and has a taper whose diameter gradually increases from the proximal end of the first portion toward the proximal end of the guidewire. a second portion of the shape ;
The guidewire, wherein the bladder is configured to accommodate a boundary between the first portion and the second portion of the core shaft. 3. The guidewire of claim 2,
A ring-shaped fixing member disposed so as to surround the outer periphery of the second portion of the core shaft, wherein the bag body is held by pinching the proximal end of the bag body between itself and the second portion. A guidewire, comprising a fixation member that seals the

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