JP2020199115A - catheter - Google Patents

Abstract

To provide a catheter in which damage of a joining portion between a core wire and a distal end tip can be suppressed.SOLUTION: A catheter includes: a first hollow shaft; a tube-like mesh member 20 whose proximal end is joined to an end portion of the first hollow shaft and which radially expands or contracts; a core wire 50 whose proximal end is positioned nearer the proximal end side than the proximal end of the first hollow shaft and which extends inside the first hollow shaft and the mesh member to the distal end side; a second hollow shaft 40 whose proximal end is positioned between a distal end of the mesh member and the proximal end thereof and extends inside the mesh member to the distal end side; and a distal end tip 30 having a joining portion joining a distal end portion 23 of the mesh member, a distal end portion 51 of the core wire and the second hollow shaft.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to catheters.

As a medical device for improving blood flow by removing an obstruction that obstructs a blood vessel such as chronic complete occlusion (CTO), for example, the obstruction is removed at a site where the obstruction in the blood vessel exists. Therefore, there is one that extends the mesh-shaped wire in the radial direction (see, for example, Patent Document 1). In addition, there is a medical device that operates the tip portion according to the operator's intention by using the operation wire at hand (see, for example, Patent Document 2).

In the medical device of Patent Document 2, the tip of the operation wire is joined to the rear end tip.

Special Table 2015-505250 JP-A-2018-102509

In a medical device such as the medical device of Patent Document 2 in which an operator pulls an operation wire to operate the tip portion, a member whose tensile force is joined to the operation wire and the operation wire and the tip portion at the time of operation. Concentrating only on the joint portion with (the rear end chip in Patent Document 1), the joint portion may be damaged.

An object of the present disclosure is to provide a catheter catheter capable of suppressing breakage of a joint portion between an operation wire (core wire in the present disclosure) and a member (tip tip in the present disclosure) to be joined to the operation wire.

In order to achieve such an object, the catheter according to one embodiment of the present disclosure is configured such that a first hollow shaft and a proximal end are joined to the tip of the first hollow shaft and expand or contract in the radial direction. A tubular mesh member, a core wire whose base end is located closer to the base end of the first hollow shaft and extends inside the first hollow shaft and the mesh member toward the tip end, and a base end. A second hollow shaft located between the tip and the base end of the mesh member and extending the inside of the mesh member toward the tip side, the tip of the mesh member, the tip of the core wire, and the second hollow shaft. A tip tip having a joint portion for joining with and is provided.

In the joint portion, the tip portion of the second hollow shaft, the tip portion of the core wire, and the tip portion of the mesh member may be arranged in this order from the inside to the outside in the radial direction.

The tip of the core wire may be formed with a recess or a through hole into which a part of the second hollow shaft enters.

In the long axis direction of the second hollow shaft, the position of the tip of the mesh member and the position of the tip of the core wire may be deviated from each other.

The present disclosure can provide a catheter capable of suppressing breakage of a joint portion between a core wire and a tip.

It is a schematic cross-sectional view of the catheter which concerns on embodiment of this disclosure, and is the figure which shows the state which the mesh member contracted. It is a schematic cross-sectional view of a catheter, and is the figure which shows the state which the mesh member expanded. (A) is a schematic cross-sectional view showing a joined state of a mesh member, a tip tip, a second hollow shaft, and a core wire, and (b) is a cross-sectional view taken along line bb of (a). It is a figure which shows the modification of the core wire.

The catheter according to the embodiment of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the embodiments described in the drawings.

In addition, in this specification, the "forward guide wire" means the guide wire which is pushed to the operative part such as the occluded part in the blood vessel prior to the catheter, and is "retrograde guide wire". Means, for example, a guide wire that comes from the tip end side of the catheter into the blood vessel.

Further, in the present specification, the “tip side” refers to a direction along the longitudinal direction of the catheter in which the tip tip is located with respect to the mesh member. The "base end side" refers to a direction along the longitudinal direction and opposite to the tip end side. The “tip” refers to the distal end of each member constituting the catheter. The "base end" refers to the end portion of each member constituting the catheter on the base end side.

FIG. 1 is a schematic cross-sectional view of the catheter 1 according to the embodiment of the present disclosure, showing a state in which the mesh member 20 is contracted.
In FIG. 1, the left side in the drawing is the distal end side (distal side) inserted into the body, and the right side is the proximal end side (hand side, proximal side) operated by a technician such as a doctor.
FIG. 2 is a schematic cross-sectional view of the catheter 1 and shows a state in which the mesh member 20 is expanded.

As shown in FIGS. 1 and 2, the catheter 1 includes a first hollow shaft 10, a mesh member 20, a tip tip 30, a second hollow shaft 40, a core wire 50, a marker 60, and a connector 70. ..

The first hollow shaft 10 has a tip end side shaft 11 and a base end side shaft 12. The tip of the tip-side shaft 11 is connected to the base end of the mesh member 20. The tip of the base end side shaft 12 is connected to the base end of the tip end side shaft 11. A connector 70 is connected to the base end of the base end side shaft 12.

The tip-side shaft 11 has a lumen 13 for inserting an antegrade guide wire (not shown), a retrograde guide wire W2 (FIG. 2), and a core wire 50 inside. The base end side shaft 12 has a lumen 14 for inserting the core wire 50 inside. At the connection portion between the distal end side shaft 11 and the proximal end side shaft 12, the distal end side shaft 11 and the proximal end side shaft 12 form a guide wire port 15 that opens toward the proximal end side. The retrograde guide wire W2 is delivered to the outside of the catheter 1 via the guide wire port 15.

As the material constituting the first hollow shaft 10, since the first hollow shaft 10 is inserted into the blood vessel, it is preferable to have antithrombotic property, flexibility and biocompatibility, and a resin material or a resin material or Metal materials can be mentioned. Since the tip end side shaft 11 is required to have flexibility, a resin material is preferable. For example, polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, fluororesin and the like can be adopted. Since the base end side shaft 12 is required to have pushability, a metal material is preferable. For example, stainless steel such as SUS304, nickel titanium alloy, cobalt chrome alloy and the like can be adopted.

The mesh member 20 is a tubular member that can expand or contract in the radial direction. When the core wire 50, which will be described later, is pulled toward the base end side, the mesh member 20 expands in diameter by being deformed out of the plane and bulging outward in the radial direction, as shown in FIG. The retrograde guide wire W2 is received by the catheter 1 through the opening of the member 20.

In the present embodiment, the mesh member 20 is formed so that a plurality of strands 21 are woven in a grid pattern to form a tube as a whole. Further, the mesh member 20 has a mesh between the knitted adjacent strands, and receives the retrograde guide wire W2 through the expanded mesh when the diameter is expanded. The tip tip 30 and the first hollow shaft 10 are joined to the tip end and the base end of each of the strands 21 constituting the mesh member 20, respectively.

Here, each wire 21 constituting the mesh member 20 can adopt either a single wire or a plurality of wires, for example, from a stranded wire in which a plurality of metal wires having different wire diameters are twisted together. It may be formed.

A metal material or a resin material can be adopted as the material constituting each wire 21 of the mesh member 20. Examples of the resin material include polyamide, polyester, polyarylate, and polyetheretherketone. From the viewpoint of improving strength and flexibility, a metal material is preferable. Examples of the metal material include stainless steel such as SUS304, nickel titanium alloy, cobalt chromium alloy and the like. The strands 21 may be made of the same material or different materials.

Further, the material constituting each strand 21 of the mesh member 20 may be a radiation opaque material from the viewpoint of improving the visibility of the mesh member 20. Examples of the radiation opaque material include gold, platinum, tungsten, and alloys containing these elements (for example, platinum-nickel alloy). The radiation-impermeable material may be a combination of the radiation-impermeable material and a material other than this material, such as a material coated on the surface of a material that is not radiation-impermeable.

The mesh member 20 is provided with an induction film 22, and the tip of the induction film 22 is located between the base end of the tip tip 30 and the tip end of the first hollow shaft 10. The guide film 22 smoothly guides the retrograde guide wire W2 (FIG. 2) received through the opening of the mesh member 20 toward the first hollow shaft 10. The tip of the guide film 22 is located substantially at the center of the mesh member 20 in the major axis direction, and the base end is located at the tip of the first hollow shaft 10. The induction film 22 is formed on the mesh member 20 so as to crosslink the adjacent strands. Here, as shown in FIG. 2, the retrograde guide wire W2 is guided into the first hollow shaft 10 through the mesh member 20 by expanding the guide film 22 into a funnel shape when the mesh member 20 expands in diameter. Be taken. The guide film 22 may be in the form of a film (not shown), for example, as long as at least a part (for example, the outer periphery of the tip of the guide film 22) is bonded to the mesh member 20.

Examples of the material constituting the induction film 22 include polyethylene, polyurethane, polyamide, polyamide elastomer, polyolefin, polyester, polyester elastomer and the like. Among these, polyurethane is preferable as the material from the viewpoint of improving the sliding property of the surface. The method for forming the guide film 22 is not particularly limited, and for example, a dip method is used for the guide film arranged on the mesh member 20, and a method for fusing the tip of the film to the mesh member 20 is used for the film-like guide film. Can be adopted.

The tip tip 30 has a substantially columnar shape and is provided on the tip side of the mesh member 20. Specifically, the tip tip 30 is formed in a sharp shape toward the tip side so that the catheter 1 can easily proceed in the blood vessel.

As the material constituting the tip tip 30, it is preferable that the catheter 1 has flexibility because it travels in the blood vessel. Examples of the material having such flexibility include resin materials such as nylon (polyamide), polyurethane, and polyurethane elastomer.

The base end of the second hollow shaft 40 is located between the tip end of the mesh member 20 and the base end, and the inside of the mesh member 20 extends toward the tip end side. The outer diameter of the second hollow shaft 40 is slightly smaller than the inner diameter of the tip tip 30. The tip 41 of the second hollow shaft 40 is inserted into the tip 30. As shown in FIG. 2, the second hollow shaft 40 has the tip and the tip of the first hollow shaft 10 in the space inside the mesh member 20 in a state where the mesh member 20 has a diameter expanded outward in the radial direction. It is configured to be located between the base end of the chip 30. This is to facilitate accepting the retrograde guide wire W2 in the first hollow shaft 10.

As the material constituting the second hollow shaft 40, since the second hollow shaft 40 is also inserted into the blood vessel in the same manner as the first hollow shaft 10 described above, antithrombotic property, flexibility and biocompatibility are improved. It is preferable to have. Examples of the material include the same materials as those exemplified in the description of the first hollow shaft 10, but a resin material is preferable from the viewpoint of flexibility.

The tip of the core wire 50 is connected to the tip tip 30, and the base end extends to the outside of the connector 70 located on the base end side of the first hollow shaft 10. Therefore, the core wire 50 penetrates the lumens 13 and 14 of the mesh member 20 and the first hollow shaft 10 and the through hole 71 of the connector 70. When the operator operates the core wire 50 outside the connector 70, the core wire 50 moves forward and backward in the major axis direction, and the mesh member 20 expands and contracts in the radial direction.

The marker 60 has a substantially annular or substantially C shape in cross-sectional view and covers the second hollow shaft 40 and the core wire 50. The marker 60 allows the base end of the second hollow shaft 40 to move together without being separated from the core wire 50.

The marker 60 is formed of a resin material such as polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, or fluororesin, or a metal material such as stainless steel such as SUS304, nickel titanium alloy, or cobalt-chromium alloy. When it is formed of a resin, it is preferable to mix it with a radiation-impermeable material such as bismuth trioxide, tungsten, or barium sulfate, and when it is formed of a metal material, it is formed of a radiation-impermeable material such as platinum or tungsten. That's good. As shown in FIG. 2, the marker 60 is preferably located near the tip of the induction film 22 when the mesh member 20 is expanded.

The connector 70 is a member for which the operator grips the catheter 1. As shown in FIG. 1, the connector 70 is connected to the base end of the first hollow shaft 10, and is a through hole that communicates with the lumens 13 and 14 of the first hollow shaft 1 so that the core wire 50 can be exposed to the outside. It has a 71 and an opening 72 formed at the base end of the through hole 71. The form of the connector 70 is not particularly limited, and any shape may be used as long as it is easy for the operator to grasp.

Next, the joining state of the mesh member 20, the tip tip 30, the second hollow shaft 40, and the core wire 50 will be described with reference to FIG.

FIG. 3A is a schematic cross-sectional view showing a joined state of the mesh member 20, the tip tip 30, the second hollow shaft 40, and the core wire 50, and FIG. 3B is a schematic cross-sectional view taken along line bb of FIG. 3A. It is a cross-sectional view.

As shown in FIGS. 3A and 3B, the tip tip 30 has a base portion 31, a first joint portion 32, and a second joint portion 33. The base portion 31, the first joint portion 32, and the second joint portion 33 may all be made of the same resin material, or may be made of different resin materials. For example, the base portion 31, the first joint portion 32, and the second joint portion 33 may be made of urethane, the base portion 31 may be made of urethane, and the first joint portion 32 and the second joint portion 33 may be made of nylon. May be good. In the base portion 31, the first joint portion 32, and the second joint portion 33, the portions in contact with each other are welded. Therefore, the base portion 31, the first joint portion 32, and the second joint portion 33 are integrated.

The base portion 31 has a base end portion 31A and a tip portion 31B, and constitutes a tip portion and an intermediate portion of the tip tip 30. The first joint portion 32 has a base end portion 32A and a tip end portion 32B. The tip portion 32B of the first joint portion 32 covers the outer circumference of the base end portion 31A of the base portion 31, and the base end portion 32A of the first joint portion 32 is closer to the base end portion 31A than the base end portion 31A of the base portion 31. positioned. The second joint portion 33 is located on the base end side of the base portion 31 and inside the base end portion 32A of the first joint portion 32. The base end portion 31A, the first joint portion 32, and the second joint portion 33 of the base portion 31 correspond to the joint portion of the tip tip 30.

In the joint portion, the tip portion 41 of the second hollow shaft 40, the tip portion 51 of the core wire 50, and the tip portion 23 of the mesh member 20 are arranged in contact with each other and overlapped from the inside to the outside in the radial direction. .. Then, the tip portion 23 of the mesh member 20, the tip portion 51 of the core wire 50, and the second hollow shaft 40 are joined to each other by the joint portion of the tip tip 30. A part of the inner circumference of the base end portion 31A of the base portion 31 and the inner circumference of the second joint portion 33 are welded to a part of the second hollow shaft 40. In this way, the tip portion 23 of the mesh member 20, the tip portion 51 of the core wire 50, and the second hollow shaft 40 are integrated by the joint portion of the tip tip 30.

A plurality of recesses 52 are formed in the tip portion 51 of the core wire 50. A part of the second hollow shaft 40 is inserted into each recess 52. That is, the second hollow shaft 40 has a convex portion that enters each concave portion 52. In the long axis direction of the second hollow shaft 40, the position of the tip of the mesh member 20 and the position of the tip of the core wire 50 are deviated from each other. In the present embodiment, the tip of the core wire 50 is located closer to the tip than the tip of the mesh member 20.

Next, an example of the usage mode of the catheter 1 described above will be described.

First, an antegrade guide wire W1 (not shown) is inserted into, for example, a blood vessel, and then pushed along the blood vessel to a site where an obstruction exists (hereinafter, also referred to as an “occluded site”). After the tip of the antegrade guide wire W1 reaches the occluded site, a balloon catheter (not shown) is inserted to the occluded site using the antegrade guide wire W1 as a guide, and the balloon is expanded to expand the occluded site. .. After expanding the occluded area, the balloon is contracted and the balloon catheter is removed from the blood vessel.

Next, the base end of the antegrade guide wire W1 is from the opening of the tip tip 30, the through hole of the tip tip 30 and the second hollow shaft 40, the space inside the mesh member 20, and the lumen 13 of the tip side shaft 11. The antegrade guide wire W1 is inserted into the catheter 1 so as to pass through the guide wire port 15 and exit the catheter 1. Using the antegrade guide wire W1 as a guide, the tip of the catheter 1 is pushed into the blood vessel to the occluded site expanded by the balloon catheter. At this time, the catheter 1 is inserted into the blood vessel with the mesh member 20 reduced in diameter, and maintains the reduced diameter until the tip of the catheter 1 reaches the occlusion site.

After the tip of the catheter 1 reaches the occlusion site, the antegrade guide wire W1 is pulled out from the catheter 1 by pulling the antegrade guide wire W1 toward the proximal end side. Next, by pulling the core wire 50 exposed to the outside of the connector 70 toward the base end side, the distance between the tip of the mesh member 20 and the tip of the first hollow shaft 10 is narrowed, and as a result, the mesh member 20 is radially It deforms out of the plane and expands its diameter. At this time, in the present embodiment, since the tip of the guiding film 22 is joined to the substantially central portion in the major axis direction of the mesh member 20, the guiding film 22 is expanded in diameter following the expansion of the mesh member 20 to guide the mesh member 20. The film 22 has a funnel shape as a whole. Since the opening is also expanded as the diameter of the mesh member 20 is increased, the retrograde guide wire W2 is easily accepted. Further, since the base end of the second hollow shaft 40 is restrained by the core wire 50 by the marker 60, the second hollow shaft 40 does not tilt and moves along the long axis direction (longitudinal direction) of the catheter 1. .. After the tip of the catheter 1 reaches the occlusion site along the antegrade guide wire W1, the diameter of the mesh member 20 is expanded, and then the antegrade guide wire W1 is pulled toward the proximal end side to antegrade. The sex guide wire W1 may be pulled out from the catheter 1.

Next, as shown in FIG. 2, the retrograde guide wire W2 coming from the distal end side is received in the catheter 1. As the path toward which the retrograde guide wire W2 is directed, for example, a false cavity in the blood vessel wall surrounding the occlusion site, a through hole penetrating the occlusion site, or the like is assumed, and the retrograde guide from any of the routes is assumed. It may be wire W2. The retrograde guide wire W2 is accepted into the space inside the mesh member 20 through the opening of the expanded mesh member 20, and then inserted into the tip end side shaft 11 of the first hollow shaft 10 and passed through the guide wire port 15. Is sent to the outside of the catheter 1.

Like the catheter 1 described above, the tip 23 of the mesh member 20, the tip 51 of the core wire 50, and the second hollow shaft 40 are joined to each other by the joint of the tip 30. In this way, since the tip portion 23 of the mesh member 20, the tip portion 51 of the core wire 50, and the second hollow shaft 40 are collectively joined by the joint portion, the operator pulls and operates the core wire 50. At that time, the tensile force is received by the three members of the mesh member 20, the core wire 50, and the second hollow shaft. Therefore, it is possible to suppress damage to the joint portion of the mesh member 20, the core wire 50, and the second hollow shaft 40 due to the joint portion.

In the joint portion, the tip portion 41 of the second hollow shaft 40, the tip portion 51 of the core wire 50, and the tip portion 23 of the mesh member 20 are arranged in this order from the inside to the outside in the radial direction. In this way, since the core wire 50 is located between the second hollow shaft 40 and the mesh member 20, the tensile force on the core wire 50 can be equally distributed between the second hollow shaft 40 and the mesh member 20. .. As a result, damage to the joint portion of the mesh member 20, the core wire 50, and the second hollow shaft 40 due to the joint portion can be further suppressed.

The tip portion 51 of the core wire 50 is formed with a recess 52 into which a part of the second hollow shaft 40 enters. Due to the anchor effect, the joint strength between the core wire 50 and the second hollow shaft 40 can be improved. Therefore, it is possible to prevent the joint portion of the mesh member 20, the core wire 50, and the second hollow shaft 40 from being damaged by the tensile force on the core wire 50.

In the long axis direction of the second hollow shaft 40, the position of the tip of the mesh member 20 and the position of the tip of the core wire 50 are deviated from each other. In the present embodiment, the tip of the core wire 50 is located closer to the tip than the tip of the mesh member 20. With this configuration, the manufacture of the catheter 1 becomes easy.

It should be noted that the present disclosure is not limited to the configuration of the above-described embodiment, but is indicated by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims. Will be done. For example, a part of the configuration of the above-described embodiment may be deleted or replaced with another configuration, or another configuration may be added to the configuration of the above-described embodiment.

For example, although a plurality of recesses 52 are formed in the tip portion 51 of the core wire 50, at least one recess 52 may be formed, and as shown in FIG. 4, a through hole 53 is used instead of the recess 52. There may be. The tip of the core wire 50 was located closer to the tip than the tip of the mesh member 20, but the tip of the core wire 50 and the tip of the mesh member 20 may be substantially the same position in the long axis direction, or the core wire. The tip of the 50 may be located closer to the base end than the tip of the mesh member 20.

1: Catheter 10: First hollow shaft 20: Mesh member 23: Tip portion 30: Tip tip 31: Base portion 31A: Base end portion 32: First joint portion 33: Second joint portion 40: Second hollow shaft 41: Tip Part 50: Core wire 51: Tip part 52: Recessed part 53: Through hole

Claims (4)

The first hollow shaft and
A tubular mesh member whose base end is joined to the tip of the first hollow shaft and is configured to expand or contract in the radial direction.
A core wire whose base end is located closer to the base end than the base end of the first hollow shaft and extends to the tip side inside the first hollow shaft and the mesh member.
A second hollow shaft whose base end is located between the tip and base ends of the mesh member and extends inside the mesh member toward the tip side.
A catheter comprising a tip portion of the mesh member, a tip portion of the core wire, and a tip tip having a joint portion for joining the second hollow shaft. The catheter according to claim 1, wherein in the joint portion, the tip portion of the second hollow shaft, the tip portion of the core wire, and the tip portion of the mesh member are arranged in this order from the inside to the outside in the radial direction. .. The catheter according to claim 1 or 2, wherein a recess or a through hole into which a part of the second hollow shaft enters is formed at the tip of the core wire. The catheter according to any one of claims 1 to 3, wherein the position of the tip of the mesh member and the position of the tip of the core wire are deviated from each other in the long axis direction of the second hollow shaft.

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