JP6563075B2 - catheter - Google Patents

Description

  The present invention relates to a catheter for capturing an obstruction in a blood vessel or capturing a retro guide wire.

  Conventionally, there are cases where the inside of a blood vessel is occluded by an obstruction, such as chronic total occlusion (CTO). As a medical device used for treatment in such a case, for example, as disclosed in Patent Document 1, a plurality of wires are mutually connected so as to expand or contract in the radial direction in order to remove an obstruction in a blood vessel. There are vascular obstruction removal devices (catheters) with braided obstruction removal elements.

  For example, Patent Document 2 discloses a catheter having a self-expandable area as a mesh. Such a catheter is provided with a cover (protective membrane) at the rear end of the self-expandable area that acts as a funnel for guiding or directing blood flow into the lumen of the catheter. ing. The cover is formed directly on the mesh by adhesive bonding, welding, coating, or the like, or attached to the mesh by connection using a mechanical fastener.

  It is also well known to use a catheter with a radially expandable mesh member as described above to capture a retro guidewire inserted from the opposite side of the occlusion in the blood vessel. ing.

Japanese Patent No. 3655920 JP 2011-517424 A

  However, in the configuration of the above-mentioned Patent Document 1, it is necessary to take in an obstruction scraped off by a plurality of expanded wires from the distal end of a small-diameter catheter, so there are many spills and the efficiency of removing the obstruction is poor. There is a problem.

  When capturing the retro guide wire, expand the obstruction removal element to raise the wire, and in this state, insert the retro guide wire into the mesh of the obstruction removal element, and then install the obstruction removal element. Since the wire is laid down forcibly and the retro guide wire is restrained by a plurality of wires, the retro guide wire may be bent forcibly and may be damaged.

  Moreover, in the structure of the said patent document 2, since there is no freedom degree of a movement of a cover with respect to the movement of a mesh, there exists a problem which cannot perform the expansion or contraction of a mesh smoothly.

  Accordingly, the present invention provides a catheter that improves the removal efficiency of occlusions in blood vessels, does not damage the retro guide wire, and can smoothly expand and contract the mesh member having a protective film. The purpose is to do.

  The present invention comprises a hollow shaft, a tubular mesh member joined to the tip of the hollow shaft, a tip attached to the tip of the mesh member, and a core wire joined to the tip. The mesh member is a catheter in which at least a first strand and a second strand are knitted together so as to expand and contract in the radial direction, and the expansion and contraction of the mesh member can be operated by the core wire. And a protective film covering at least a part of the inner periphery on the rear end side of the mesh member, wherein the protective film is bonded to only one of the first strand and the second strand. A catheter characterized by that.

  In such a configuration, the obstruction in the blood vessel can be guided to the distal end of the catheter by the protective film, so that the removal efficiency of the obstruction can be improved. In addition, the retro guide wire that has entered the mesh member can be smoothly guided into the catheter as it is by the guiding action of the protective film, so there is no need to constrain the retro guide wire by the expansion / contraction operation of the mesh member. The guide wire will not be damaged. Furthermore, in the mesh member to which the protective film is bonded in the above-described aspect, the first strand and the second strand are not bound to each other via the protective film. The member can be smoothly expanded and contracted.

  Moreover, it is desirable that the rear end of the protective film extends to the position of the front end of the hollow shaft.

  In such a configuration, the obstruction in the blood vessel and the retro guide wire can be smoothly guided into the hollow shaft without leakage at the joint portion between the mesh member and the hollow shaft.

  Furthermore, while the front-end | tip part of the said protective film is joined only to either one of said 1st strand of said mesh member and said 2nd strand, the rear-end part of said protective film is said 1st It is desirable that it is not joined to either the strand or the second strand.

  In such a configuration, when the diameter of the mesh member is increased, the tip of the protective film is expanded in the radial direction following the mesh member. On the other hand, since the rear end portion of the protective film does not follow the movement of the mesh member, it is not expanded in the radial direction. Therefore, by adopting such a configuration, the shape of the protective film when the diameter of the mesh member is expanded can be a funnel shape having a diameter reduced toward the rear end direction. Further, since the rear end portion of the protective film is not joined to either the first strand or the second strand of the mesh member, the flexibility of the catheter in the blood vessel is not impaired.

  The catheter of the present invention improves the removal efficiency of the obstruction in the blood vessel, does not damage the retro guide wire, and can smoothly perform the expansion / contraction operation of the mesh member having the protective film. There is.

The catheter of the state which the mesh member concerning Example 1 contracted is shown, (a) is an outline figure showing an outline, and (b) is an AA sectional view of (a). It is a schematic diagram which shows the catheter of the state which the mesh member concerning Example 1 expanded. FIG. 2 is a partially enlarged cross-sectional view illustrating a bonding mode between a mesh member and a protective film according to Example 1 and illustrating an enlarged BB cross section of FIG. It is a schematic diagram which shows the use condition which is the catheter concerning Example 1 and the retro guide wire was penetrated. It is a schematic diagram which shows the catheter concerning Example 2. FIG. It is a schematic diagram which shows the catheter concerning Example 3. FIG. The catheter concerning Example 4 is shown, (a) is a schematic diagram which shows an outline | summary, (b) is CC sectional drawing of (a).

  Hereinafter, the embodiment which actualized the catheter of the present invention is described in detail. However, the present invention is not limited to the examples shown below, and the design can be changed as appropriate. In FIGS. 1 (a), 2 and 4 to 7 (a), the left side is the distal end side (distal side) to be inserted into the body, and the right side is operated by an operator such as a doctor. This is the rear end side (proximal side, proximal end side).

[Example 1]
For example, the catheter 11 used for removing the obstruction in the blood vessel is provided with a hollow shaft 20 as shown in FIG. 1 (a), FIG. 1 (b), and FIG.

  The hollow shaft 20 has a hollow tube shape with a lumen 23 therein, and an RX port 21 that opens toward the rear end side is formed on a side wall located between the front end portion and the rear end portion. Has been.

  The hollow shaft 20 is preferably composed of a tube made of a resin such as polyamide, polyamide elastomer, polyolefin, polyester, or polyester elastomer. Different materials may be used for the rear end side and the front end side. For example, the rear end side may be made of a superelastic alloy such as stainless steel (SUS304) or a Ni—Ti alloy.

  A mesh member 30 is joined to the tip 22 of the hollow shaft 20. More specifically, the mesh member 30 has a tube shape in which a first strand 31 and a second strand 32 are knitted together, and the mesh member 30 has a rear end 36 and a front end 22 of the hollow shaft 20. Are connected so that the mesh member 30 and the hollow shaft 20 are substantially coaxial.

  The first strand 31 and the second strand 32 constituting the mesh member 30 are preferably made of a metal material such as stainless steel (SUS304). In particular, by using a radiopaque material (for example, tungsten or Co—Cr alloy) for at least one of the first strand 31 and the second strand 32, a procedure is performed during coronary angiography. A person can accurately grasp the position of the mesh member 30.

  Further, a tip chip 40 is joined to the tip 37 of the mesh member 30. More specifically, the distal tip 40 has a tube shape, and an opening 41 is formed at the distal end of the distal tip 40.

  The tip 40 is preferably formed of a flexible resin such as polyurethane or polyurethane elastomer.

  The tip of the core wire 50 is joined to the rear end of the tip chip 40. More specifically, the core wire 50 is inserted into the hollow shaft 20 (lumen 23), and is formed of a tapered metal wire having a circular cross section and a diameter decreasing toward the tip. ing. As will be described in detail later, the mesh member 30 can be expanded and contracted in the radial direction by operating the core wire 50 in the axial direction.

  A connector 60 is joined to the rear end of the hollow shaft 20.

  Further, a thin and flexible protective film 70 </ b> A is disposed in a tube shape on the inner periphery of the rear end side 35 of the mesh member 30. In FIG. 1A and FIG. 2, the hollow shaft 20, the tip 40, the connector 60, and the core wire 50 disposed in the hollow shaft 20 and the mesh member 30 are shown in a cross-sectional view to help understanding. Show. However, the core wire 50 located in the protective film 70A is indicated by a broken line.

  The protective film 70A is preferably made of a resin such as polyethylene, polyurethane, polyamide, polyamide elastomer, polyolefin, polyester, or polyester elastomer, and a material used for a balloon of a general balloon catheter is preferable. Applicable to.

Hereafter, the principal part of this invention is demonstrated.
The protective film 70 </ b> A covers the entire inner circumference of the rear end side 35 of the mesh member 30. Further, the rear end 71 of the protective film 70A extends to the position of the front end 22 of the hollow shaft 20, and the rear end 71 of the protective film 70A is not joined to the front end 22 of the hollow shaft 20. Located in the hollow shaft 20.

  Further, only the tip of the protective film 70A is joined to the mesh member 30 by the adhesive 75, and the protective film 70A is not joined to any position of the mesh member 30 except for the tip. It is set as the junction part Q.

  More specifically, as shown in FIG. 3, the front end portion of the protective film 70 </ b> A is joined to the first strand 31 of the mesh member 30 via an adhesive 75, and the first strand 31. Is not joined to the second strand 32 that intersects with. Therefore, the protective film 70A and the second strand 32 can be individually moved relative to each other without being constrained to each other.

  Next, the usage aspect of the catheter 11 mentioned above is demonstrated.

  In the catheter 11, the diameter of the mesh member 30 is increased by changing the relative distance between the distal tip 40 and the hollow shaft 20 by operating the core wire 50 in the axial direction (FIG. 2). Reference) or a reduced diameter state (see FIG. 1A).

  The catheter 11 is inserted into the blood vessel with the mesh member 30 having a reduced diameter as shown in FIG. Next, for example, when the mesh member 30 reaches a predetermined position such as a CTO portion, the core wire 50 is operated so that the mesh member 30 is expanded in diameter as shown in FIG. In addition, the position which makes the said mesh member 30 an expanded state can be changed suitably according to a condition.

  As the mesh member 30 is expanded in diameter, the front end side of the protective film 70A is also expanded following the state change of the mesh member 30, and the entire protective film 70A has a funnel shape ( (See FIG. 2).

  In the state where the diameter of the mesh member 30 is expanded as described above, an obstruction or the like can be taken into the hollow shaft 20 from the tip 72 of the protective film 70A.

  When the retro guide wire 80 is inserted from the opposite side of the catheter 11, the retro guide wire 80 is introduced into the distal end portion of the mesh member 30 in the expanded state as shown in FIG. The retro guide wire 80 is inserted into the mesh member 30 from the introduction portion P. The retro guidewire 80 inserted into the mesh member 30 is guided into the hollow shaft 20 by the guiding action of the protective film 70A having a funnel shape. Thereafter, the retro guidewire 80 is recovered outside the body via the lumen 23 and the RX port 21 of the hollow shaft 20. Thereby, the retro guide wire 80 guided in the catheter 11 is captured without being damaged. Thus, the catheter 11 of the present embodiment can be suitably used as a medical device combined with the retro guidewire 80.

  Here, since the tip of the protective film 70A in this embodiment is joined only to the first strand 31 constituting the mesh member 30, the degree of freedom in expanding the mesh member 30 is high. . In other words, when the diameter of the mesh member 30 is increased, the tip of the protective film 70A is expanded in the radial direction following only the movement of the first strand 31 of the mesh member 30. Therefore, in the mesh member 30, there is no problem that the first strand 31 and the second strand 32 are restrained by the tip of the protective film 70 </ b> A. Scaling is performed smoothly.

  Furthermore, since the rear end portion of the protective film 70A is not joined to the first strand 31 and the second strand 32, it is not expanded in the radial direction even when the mesh member 30 is expanded. Therefore, the protective film 70A when the diameter of the mesh member 30 is increased can be easily formed into a funnel shape having a diameter reduced toward the rear end direction. In addition, since the rear end portion of the protective film 70A is not joined to either the first strand 31 or the second strand 32 of the mesh member 30, the flexibility of the catheter 11 in the blood vessel is increased. Not damaged.

  Further, as described above, the rear end 71 of the protective film 70A extends to the position of the front end 22 of the hollow shaft 20, and therefore, in the joint portion between the mesh member 30 and the hollow shaft 20, The obstruction and the retro guide wire 80 can be smoothly guided into the hollow shaft 20 without leakage. The rear end 71 of the protective film 70A may extend to a position closer to the rear end side than the front end 22 of the hollow shaft 20 (in other words, to the lumen 23 of the hollow shaft 20).

[Example 2]
The catheter 12 of Example 2 is demonstrated according to FIG. In addition, what has the structure similar to the said Example 1 attaches | subjects the same code | symbol, and abbreviate | omits description.

  In the catheter 12, the rear end 73 of the protective film 70 </ b> B and the front end 22 of the hollow shaft 20 are separated by a distance d, and the protective film 70 </ b> B partially covers the inner periphery on the rear end side of the mesh member 30. Is covered. In such a configuration, since the rear end 73 of the protective film 70B is not restrained by the hollow shaft 20, the degree of freedom when the protective film 70B expands or contracts further increases, and the mesh member 30 is expanded or contracted. Becomes even smoother.

Example 3
The catheter 13 of Example 3 is demonstrated according to FIG. In addition, what has the structure similar to the said Example 1 attaches | subjects the same code | symbol, and abbreviate | omits description.

  The protective film 70A of the catheter 13 is joined to only the first strand 31 of the mesh member 30 via an adhesive 75 from the front end portion to the rear end portion of the protective film 70A. That is, the catheter 13 does not substantially include the non-joining portion Q described above. Even in this configuration, since the protective film 70A is joined only to the first strand 31 of the mesh member 30, the mesh member 30 is smoothly expanded and contracted.

Example 4
The catheter 14 of Example 4 is demonstrated according to FIG. 7 (a), (b). In addition, what has the structure similar to the said Example 1 attaches | subjects the same code | symbol, and abbreviate | omits description.

  The catheter 14 has a so-called two-lumen structure, and the hollow shaft 20 has a second hollow shaft 25 inserted therein, which is different from the hollow shaft 20, and the hollow shaft 20 and the second hollow shaft 25 are welded to each other. Has been. A lumen 23 is formed between the hollow shaft 20 and the second hollow shaft 25, a second lumen 24 is formed inside the second hollow shaft, and a core wire 50 is inserted through the second lumen 24. In such a configuration, unlike the catheters 11, 12, and 13 of the first to third embodiments, the core wire 50 is not inserted into the lumen 23 of the hollow shaft 20. The interference between the core wire 50 and the retro guide wire 80 can be preferably avoided. In addition, since the obstruction taken into the lumen 23 of the hollow shaft 20 does not adhere to the core wire 50, the operation in the axial direction of the core wire 50 is not hindered by the obstruction and the mesh member 30 can be expanded or contracted. It can be done smoothly.

  In addition, this invention can be suitably changed besides the said Examples 1-4. For example, the hollow shaft 20 may have a single layer structure or a multilayer structure having a plurality of layers.

  Moreover, the mesh member 30 is not limited to what is comprised only by the 1st strand 31 and the 2nd strand 32, You may be comprised by adding another strand further.

  Further, the catheters 11, 12, 13, and 14 are not limited to the configuration in which the protective films 70A and 70B and the first strand 31 are joined via the adhesive 75. The structure welded and joined to the one strand 31 may be sufficient. Further, in the catheters 11, 12, 13, and 14, the joining means is not particularly limited with respect to the joined portions between the members.

  Further, the protective films 70 </ b> A and 70 </ b> B may be joined only to the second strand 32 instead of the first strand 31. In Examples 1 to 4, the protective films 70A and 70B and the first strand 31 were joined at a position shifted from the intersection where the first strand 31 and the second strand 32 intersect. It is not limited to this. The protective films 70 </ b> A and 70 </ b> B may be joined to only one of the first strand 31 and the second strand 32 at the intersection where the first strand 31 and the second strand 32 intersect.

  The protective films 70A and 70B are made of, for example, a mesh material that is finer than the mesh member 30 as long as it can guide the obstruction in the blood vessel and the retro guide wire 80 into the hollow shaft 20. It may be what was done.

  Of course, a plurality of the protective films 70A and 70B may be arranged in the axial direction with respect to the mesh member 30.

  In addition, the well-known thing generally used can be used conveniently for the retro guidewire 80. FIG.

11, 12, 13, 14 Catheter 20 Hollow shaft 22 Tip 25 Core shaft 30 Mesh member 31 First strand 32 Second strand 35 Rear end portion 40 End tip 50 Core wire 70A, 70B Protective film 71 Rear end

Claims (2)

A hollow shaft;
A tubular mesh member joined to the tip of the hollow shaft;
A tip chip joined to the tip of the mesh member;
A core wire joined to the tip,
With
The mesh member is a catheter in which at least a first strand and a second strand are knitted together so as to expand and contract in the radial direction, and the expansion and contraction of the mesh member can be operated by the core wire. ,
A protective film covering at least a part of the inner periphery of the rear end side of the mesh member;
The catheter, wherein the protective film is bonded to only one of the first strand and the second strand. The catheter according to claim 1, wherein a rear end of the protective film extends to a position of a front end of the hollow shaft.

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