Catheter

Abstract

To provide a catheter which can exhibit excellent supportability and guide properties with a simple structure.SOLUTION: A catheter 1 includes a first tube 11, and a second tube 21 which is disposed to surround an outer peripheral surface 11a of the first tube 11 and can move along a longitudinal direction of the first tube 11. The second tube 21 has at least any of a plurality of through holes 31, blind holes 32, penetrating slits 51, and non-penetrating slits 52 extending radially inward from an outer peripheral surface 21a of the second tube 21 and formed along a longitudinal direction of the second tube 21.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to catheters. [Background technology]

[0002] When inserting a long medical device into a body cavity, for example, a catheter having an inner lumen for inserting the medical device is used.

[0003] Such a catheter is required to have excellent support properties that enable it to maintain a medical device at a predetermined location within a body cavity, as well as high guidance properties that enable it to be smoothly advanced to the predetermined location.

[0004] In order to achieve the above-mentioned support and guidance, for example, a catheter has been proposed that forms a lumen with a closed tip and adjusts the rigidity by injecting fluid into the lumen to adjust the internal pressure (see, for example, Patent Document 1).

[0005] Increasing the fluid pressure of the catheter increases the rigidity of the catheter, which is expected to provide high support for the medical device within the body cavity, while decreasing the fluid pressure increases the flexibility of the catheter, which is expected to allow for easier guidance of the catheter within the body cavity. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2021-168974 Summary of the Invention [Problem to be solved by the invention]

[0007] In conventional catheters such as those described above, when introducing a liquid into the lumen, a device is required to degas the lumen to remove any air from it and to apply pressure to the liquid, which requires a large-scale device and tends to make operation complicated.

[0008] The catheter of the present disclosure provides a catheter that has a simple configuration and is capable of providing excellent support and guidance. [Means for solving the problem]

[0009] The catheter of the present disclosure comprises: (1) a first tube; and a second tube arranged to surround the outer peripheral surface of the first tube and movable along the longitudinal direction of the first tube, the second tube having at least one of through holes, non-through holes, through slits, and non-through slits formed along the longitudinal direction of the second tube and extending radially inward from the outer peripheral surface of the second tube. According to this configuration, excellent support and guidance can be obtained with a simple configuration.

[0010] (2) In the catheter of (1), The second tube may have the hole therethrough. This configuration can enhance support by anchoring to the tissue.

[0011] (3) In the catheters of (1) and (2), The through holes, the non-through holes, the through slits, and the non-through slits may extend along a circumferential direction of the second tube. According to this configuration, the second tube can be easily bent, and the inductivity can be improved. (4) In the catheter of (1) to (3), The second tube may have a length in the longitudinal direction that is shorter than the length of the first tube in the longitudinal direction. With this configuration, the operator can move the first tube toward the proximal end and expose the distal end of the first tube to the outside, which allows the distal end of the first tube to exhibit good flexibility, thereby providing the catheter with excellent guiding properties. (5) In the catheter of (1) to (4), The device may include a gripping member connected to a proximal end of the first tube and having an outer diameter greater than an inner diameter of the second tube. This configuration prevents the operator from pulling the second tube out from the first tube toward the proximal end, thereby providing a practical catheter with excellent operability. (6) In the catheter of (1) to (5), the first tube includes a hydrophilic coating layer; The outer peripheral surface of the hydrophilic coating layer may constitute the outer peripheral surface of the first tube. According to this configuration, the guidance of the first tube can be further improved. (7) In the catheter of (1) to (6), The outer circumferential surface of the second tube may not be provided with a hydrophilic coating layer. This configuration makes it difficult for the second tube to slip, thereby further improving the support of the medical device by the catheter.

[0012] As used herein, "distal side" refers to the direction along the long axis of the catheter (longitudinal direction) and the direction in which the catheter advances toward a specific site in the body cavity (distal side). "Proximal side" refers to the direction along the long axis of the catheter (longitudinal direction) and the direction opposite to the distal side (proximal side). "Distal" refers to the distal end of any component, and "proximal end" refers to the proximal end of any component. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic vertical cross-sectional view showing a first embodiment. [Figure 2] FIG. 2 is a schematic enlarged longitudinal sectional view showing a part of FIG. 1. [Figure 3] FIG. 2 is a schematic plan view showing an enlarged view of a part of FIG. [Figure 4] FIG. 4 is a schematic cross-sectional view taken along line IV-IV in FIG. 2. [Figure 5] FIG. 2 is a schematic vertical cross-sectional view showing a first state in the first embodiment. [Figure 6] FIG. 4 is a schematic vertical cross-sectional view showing an example of a second state in the first embodiment. [Figure 7] FIG. 4 is a schematic vertical cross-sectional view showing an example of a second state in the first embodiment. [Figure 8] FIG. 2 is a schematic diagram showing an example of a first state during use. [Figure 9] FIG. 10 is a schematic diagram showing an example of a second state during use. [Figure 10] FIG. 10 is a schematic enlarged view of a part of FIG. 9. [Figure 11] FIG. 10 is a schematic diagram showing an example of a medical device delivered in a second state during use. [Figure 12] FIG. 10 is a schematic vertical cross-sectional view showing a second embodiment. [Figure 13] FIG. 13 is a schematic enlarged longitudinal sectional view showing a part of FIG. 12. [Figure 14] FIG. 13 is a schematic plan view showing an enlarged portion of FIG. 12. [Figure 15] FIG. 14 is a schematic cross-sectional view taken along line XV-XV in FIG. 13. [Figure 16] FIG. 10 is a partially enlarged schematic plan view showing a modified example of the embodiment. [Figure 17] FIG. 10 is a partially enlarged schematic plan view showing a modified example of the embodiment. [Figure 18] FIG. 10 is a partially enlarged schematic plan view showing a modified example of the embodiment. [Figure 19] FIG. 10 is a partially enlarged schematic plan view showing a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] The catheter of the present disclosure comprises a first tube and a second tube arranged to surround the outer peripheral surface of the first tube and movable along the longitudinal axis of the first tube, the second tube having at least one of through holes, non-through holes, through slits, and non-through slits formed along the longitudinal axis of the second tube and extending radially inward from the outer peripheral surface of the second tube.

[0015] Hereinafter, first and second embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the embodiments shown in the drawings. The dimensions of each part shown in the drawings are shown to facilitate understanding of the implementation content and do not necessarily correspond to the actual dimensions.

[0016] In Figures 1-3, 5-7, 12-14, and 16-19, the left side of the figure is the tip side (distal side) that is inserted deeper into the body, and the right side is the base side (proximal side, hand side) that is operated by a doctor or other technician.

[0017] [First embodiment] 1 to 11 are schematic diagrams showing a first embodiment. As shown in FIGS. 1 to 4, a catheter 1 includes a first tube 11, a second tube 21, and a gripping member 41.

[0018] The first tube 11 is a hollow member. For example, the first tube 11 has an opening 11c at the tip end and an opening 11d at the base end. The first tube 11 has an inner cavity 11h that penetrates the first tube 11 from the tip end to the base end in the longitudinal direction.

[0019] Since the material constituting the first tube 11 is inserted into a body cavity, it is preferable that it has antithrombogenicity, flexibility, and biocompatibility. Examples of materials constituting the first tube 11 include resin materials such as polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluororesin. The first tube 11 may include a portion made of a metal material, such as a hypotube, on the proximal side of the portion made of a resin material.

[0020] The first tube 11 may include a hydrophilic coating layer (not shown). In such a case, the outer circumferential surface of the hydrophilic coating layer may constitute the outer circumferential surface 11a of the first tube 11. The hydrophilic coating is exposed on the outer circumferential surface 11a of the first tube 11. Therefore, the hydrophilic coating can be in direct contact with either the wall of the body cavity or the inner circumferential surface of the second tube 21.

[0021] The material forming the hydrophilic coating layer preferably has antithrombogenicity and biocompatibility. Examples of such materials include polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, polyacrylamide, polyacrylic acid, sodium polyacrylate, poly(2-hydroxyethyl methacrylate), maleic anhydride copolymers, ethylene-vinyl alcohol copolymers, 2-methacryloyloxyethyl phosphorylcholine, 2-methacryloyloxyethyl phosphorylcholine copolymers, (2-hydroxyethyl methacrylate)-styrene block copolymers, various synthetic polypeptides, collagen, hyaluronic acid, cellulose-based polymers, and crosslinked products thereof. The above materials may be used alone or in combination of two or more.

[0022] The region of the first tube 11 on which the hydrophilic coating layer is provided is not particularly limited. The region may be a part of the longitudinal direction or the entire longitudinal direction. The region may be divided into two or more independent regions.

[0023] By including the hydrophilic coating layer in the first tube 11, it is possible to further improve the guidance of the first tube 11 when inserting the catheter 1 into a body cavity in a first state described below. This is presumably because the hydrophilic coating layer is exposed to the outside in the first state, and the hydrophilic coating layer absorbs moisture from within the body cavity upon contact with the body cavity wall, resulting in an increase in lubricity due to the liquid film formed on the outer circumferential surface 11a of the first tube 11 (reducing the frictional resistance between the catheter 1 and the body cavity wall).

[0024] The second tube 21 is a hollow member. The second tube 21 has, for example, an opening 21c at the distal end and an opening 21d at the proximal end. The second tube 21 has, for example, an inner cavity 21h that penetrates from the distal end to the proximal end in the longitudinal direction of the second tube 21. The second tube 21 is disposed so as to surround the outer circumferential surface 11a of the first tube 11 and is disposed so as to be movable along the longitudinal direction of the first tube 11. Specifically, the second tube 21 is, for example, a substantially cylindrical member that is fitted onto the outer periphery of the first tube 11. As shown in FIG. 4, the second tube 21, for example, surrounds the entire circumferential direction of the first tube 11.

[0025] The length of the second tube 21 in the longitudinal direction is not particularly limited. For example, the length of the second tube 21 in the longitudinal direction may be shorter than the length of the first tube 11 in the longitudinal direction. This increases the rigidity of the catheter 1 in the area where the first tube 11 and the second tube 21 overlap, and decreases the rigidity in the area where the first tube 11 and the second tube 21 do not overlap. The catheter 1 has a portion with high rigidity, which improves the support of the medical device by the catheter 1, and a portion with low rigidity, which improves the guideability of the catheter 1.

[0026] That is, when the operator moves the first tube 11 toward the base end and exposes the distal end portion of the first tube 11 to the outside, the rigidity of the distal end portion of the first tube 11 decreases, improving guidance. When the operator moves the first tube 11 toward the distal end and surrounds the distal end portion of the first tube 11 with the second tube 21, the rigidity of the distal end portion of the first tube 11 increases, improving support.

[0027] The material forming the second tube 21 is preferably antithrombotic and biocompatible, since it is inserted into a body cavity. Examples of materials forming the second tube 21 include resin materials such as polyamide resin, polyolefin resin, polyester resin, polyurethane resin, silicone resin, and fluororesin. The second tube 21 may include a portion formed of a metal material, such as a hypotube, on the proximal side of the portion formed of the resin material.

[0028] The second tube 21 has a plurality of through holes, non-through holes, through slits, and non-through slits formed along the longitudinal axis of the second tube 21, the through holes extending radially inward from the outer peripheral surface 21a of the second tube 21. In this embodiment, the second tube 21 has through holes 31 (hereinafter also referred to as "through holes 31") extending radially inward from the outer peripheral surface 21a of the second tube 21.

[0029] The through holes, non-through holes, through slits, and non-through slits may extend along the circumferential direction of the second tube 21. The through holes and through slits may extend in an arc shape along the circumferential direction of the second tube 21. The non-through holes and non-through slits may extend in an arc shape or in an annular shape along the circumferential direction of the second tube 21.

[0030] The number of through holes, non-through holes, through slits, and non-through slits provided in the second tube 21 is not particularly limited. In this embodiment, a plurality of through holes 31 are provided in opposing side portions along the longitudinal direction of the second tube 21. As shown in FIG. 10 , in a curved portion of the second tube 21, the opening area of ​​the through holes 31 located on the outside of the curved portion is large, and the opening area of ​​the through holes 31 located on the inside of the curve is small. This can improve the guidance of the catheter 1.

[0031] The shapes of the through hole, non-through hole, through slit, and non-through slit are not particularly limited. In this embodiment, as shown in Fig. 3, a through hole 31A having a substantially rectangular opening shape on the outer circumferential surface 21a of the second tube 21 is exemplified. The long side of the through hole 31A is formed in an arc shape along the circumferential direction of the second tube 21.

[0032] The hydrophilic coating layer does not have to be provided on the outer peripheral surface 21a of the second tube 21. This makes the second tube 21 less slippery. As a result, the supportability of the medical device by the catheter 1 can be further improved.

[0033] The gripping member 41 is a member used by the operator to push the first and second tubes 11, 21 into the body and to apply a rotational force to the first tube 11. The gripping member 41 of this embodiment is connected to the base end of the first tube 11. The gripping member 41 has an opening 41a at the base end and an opening 41b at the tip. The gripping member 41 has an inner cavity 41h that passes through the gripping member 41 from the tip to the base end in the longitudinal direction. The inner cavity 41h is in communication with the inner cavity 11h.

[0034] The gripping member 41 may have an outer diameter larger than the inner diameter of the second tube 21. This prevents the operator from pulling the second tube 21 out toward the proximal end from the first tube 11. This makes it possible to obtain a practical catheter with excellent operability.

[0035] The inner cavities 11h and 41h form a lumen L. For example, a guide wire, a medical device, etc., is inserted through the lumen L.

[0036] The catheter 1 can be selectively switched between, for example, a first state and a second state described below by moving the second tube 21 along the longitudinal direction of the first tube 11.

[0037] 5, the first state is a state in which the tip of the second tube 21 is located closer to the base end than the tip of the first tube 11, and the tips of the first tube 11 and the second tube 21 are arranged with a predetermined distance Lx between them. In the first state, the outer peripheral surface 11a of the first tube 11 at the tip end of the catheter 1 is exposed to the outside.

[0038] 6, the second state is a state in which the tip of the second tube 21 is located closer to the base end than the tip of the first tube 11, and the tips of the first tube 11 and the second tube 21 are spaced apart by a distance Ly that is smaller than the distance Lx in the first state. In the second state, the entire outer peripheral surface 11a of the tip portion of the first tube 11 may be covered by the second tube 21, as shown in FIG.

[0039] A description will be given of a mode of use of the catheter of the present disclosure, in which a procedure is described in which the catheter 1 is used to support a medical device D near the aortic arch.

[0040] First, a guide wire (not shown) is inserted into a blood vessel, and its tip is advanced to the site to be treated in advance. Next, a guiding catheter E is advanced within the blood vessel V along the guide wire.

[0041] Next, the catheter 1 in the first state is delivered to the site to be supported. Specifically, after the catheter 1 is set to the first state, it is advanced along the guide catheter E as shown in Figure 8. Then, the guide catheter E is pulled out of the body from the catheter 1.

[0042] Next, the catheter 1 is switched to the second state. Specifically, while manipulating the base end of the second tube 21, the second tube 21 is advanced along the first tube 11 as shown in Fig. 9. At this time, as shown in Fig. 10, since the second tube 21 has a through-hole 31, part of the tissue of the blood vessel V may enter the through-hole 31 or the edge of the second tube 21 around the through-hole 31 may get caught on the tissue of the blood vessel V.

[0043] Next, the medical device D is delivered along the catheter 1. Specifically, as shown in FIG. 11 , the medical device D is pushed forward while being supported by the catheter 1. Then, the medical device D is used to treat the area to be treated. For example, a thrombus aspiration catheter is used as the medical device D to aspirate a thrombus within a blood vessel. In this use example, the medical device D is supported by the catheter 1 mainly at the area where the descending aorta branches off into the right common carotid artery via the brachiocephalic trunk.

[0044] After the treatment using the medical device D is completed, the medical device D, the catheter 1, and the guide wire are removed from the body. These operations complete the series of procedures.

[0045] As described above, the catheter 1 has the above-described configuration, and thus can provide excellent support and guidance with a simple configuration. This is presumably because, in the second state, part of the tissue of the blood vessel V enters the through-hole 31, or the edge of the second tube 21 around the through-hole 31 gets caught on the tissue of the blood vessel V, thereby anchoring the second tube 21 to the inner wall of the blood vessel V and restricting movement of the second tube 21 within the blood vessel V, and as a result, the catheter 1 can be stably placed inside the blood vessel V.

[0046] The catheter 1 has a hole 31 through which the second tube 21 passes, thereby improving support by anchoring to the tissue.

[0047] The catheter 1 has a through-hole 31 that extends circumferentially around the second tube 21. This allows the second tube 21 to bend easily, improving guidance. In addition, the through-hole 31 expands when the second tube 21 is bent, allowing for smooth and reliable anchoring to the blood vessel V.

[0048] [Second embodiment] 12 to 15 are schematic diagrams showing the second embodiment. As shown in FIGS. 12 to 15, the catheter 2 includes a first tube 11, a second tube 22, and a gripping member 41. The catheter 2 differs from the first embodiment in that it includes the second tube 22. The configurations of the first tube 11 and the gripping member 41 are the same as those of the first embodiment. Since the configurations other than the configuration of the second tube 22 shown below are the same as those of the first embodiment, the same parts are given the same reference numerals and detailed description thereof will be omitted. The manner of use of the catheter 2 is the same as that of the first embodiment.

[0049] The second tube 22 is a hollow member. The second tube 22 is disposed so as to surround the outer circumferential surface 11a of the first tube 11 and is disposed so as to be movable along the longitudinal direction of the first tube 11.

[0050] The second tube 22 has a plurality of through holes, non-through holes, through slits, and non-through slits extending radially inward from the outer surface 22a of the second tube 22 formed along the longitudinal axis of the second tube 22.

[0051] The second tube 22 of this embodiment has non-through holes 32 (hereinafter also referred to as "non-through holes 32") extending radially inward from the outer circumferential surface 22a of the second tube 22. The non-through holes 32 are bottomed recesses recessed radially inward from the outer circumferential surface 22a.

[0052] There is no particular limitation on the number of non-through holes 32. In this embodiment, the non-through holes 32 are provided in opposing side surface portions of the second tube 22 along the longitudinal direction of the second tube 22.

[0053] There are no particular limitations on the opening shape of the non-through hole 32. In this embodiment, as shown in Fig. 14, a non-through hole 32A having a circular opening shape in the outer circumferential surface 22a of the second tube 22 is exemplified.

[0054] As in the first embodiment, the catheter 2 can be selectively switched between a first state and a second state by moving the second tube 22 along the longitudinal direction of the first tube 11.

[0055] As described above, the catheter 2 has the above-described configuration, and thus can obtain excellent support and guidance with a simple configuration. This is presumably because, in the second state, part of the tissue of the blood vessel V enters the non-through hole 32, or the edges of the second tube 22 around the non-through hole 32 get caught on the tissue of the blood vessel V, thereby anchoring the second tube 22 to the inner wall of the blood vessel V and restricting movement of the second tube 22 within the blood vessel V, and as a result, the catheter 2 can be stably placed inside the blood vessel V.

[0056] The present disclosure is not limited to the configurations of the above-described embodiments, but is intended to include all modifications within the meaning and scope of the claims as defined by the claims. Part of the configurations of the above-described embodiments may be deleted or replaced with other configurations, or other configurations may be added to the configurations of the above-described embodiments.

[0057] In the first and second embodiments described above, the catheters 1 and 2 have been described in which the through holes 31 and non-through holes 32 are always open. However, the through holes 31 and non-through holes 32 may be formed to be openable. For example, they may be slits that temporarily open only when the second tube is bent and a portion of tissue enters. The slits may be through slits 51 that extend radially inward from the outer circumferential surface 23a of the second tube 23, as shown in FIG. 16 . The slits may also be non-through slits 52 that do not penetrate the second tube 23. The second tube may be provided with only either through slits or non-through slits.

[0058] In the above-described first and second embodiments, the catheters 1 and 2 are described in which the through holes 31 and the non-through holes 32 are provided in the second tubes 21 and 22. However, the through holes and the non-through holes may be provided alternately along the longitudinal direction of the second tube.

[0059] In the first embodiment described above, the catheter 1 has been described in which the opening shape of the through hole 31 is substantially rectangular. In the second embodiment, the catheter 2 has been described in which the opening shape of the non-through hole 32 is circular. However, the through hole 31 and the non-through hole 32 may be, for example, through hole 31B and non-through hole 32B having substantially rectangular openings extending along the major axis direction in plan view (see FIG. 17), through hole 31C and non-through hole 32C having elliptical openings extending along the circumferential direction (see FIG. 18), or through hole 31D and non-through hole 32D having elliptical openings extending along the major axis direction (see FIG. 19).

[0060] The first tube and the second tube may each be configured by stacking multiple tube layers. A cylindrical reinforcing body may be provided inside the first tube and the second tube. Examples of the cylindrical reinforcing body include a coil body and a cylindrical mesh body.

Claims

1. A first tube (11); a second tube (21, 22) arranged to surround the outer peripheral surface (11a) of the first tube (11) and movable along the longitudinal direction of the first tube (11), wherein at least one of through holes (31), non-through holes (32), through slits (51), and non-through slits (52) extending radially inward from the outer peripheral surface (21a, 22a) of the second tube (21, 22) is formed along the longitudinal direction of the second tube (21, 22).

2. 2. The catheter (1) according to claim 1, wherein the two tubes (21) have the through holes (31).

3. A catheter (1, 2) as described in claim 1 or claim 2, wherein the through hole (31), the non-through hole (32), the through slit (51), and the non-through slit (52) extend along the circumferential direction of the second tube (21, 22).

4. The catheter (1, 2) according to any one of claims 1 to 3, wherein the length of the second tube (21, 22) in the longitudinal direction is shorter than the length of the first tube (11) in the longitudinal direction.

5. A catheter (1, 2) as described in any one of claims 1 to 4, comprising a gripping member (41) connected to the proximal end of the first tube (11) and having an outer diameter larger than the inner diameter of the second tube (21, 22).

6. the first tube (11) comprises a hydrophilic coating layer; The catheter (1, 2) according to any one of claims 1 to 5, wherein the outer surface of the hydrophilic coating layer forms the outer surface (11a) of the first tube (11).

7. The catheter (1, 2) according to any one of claims 1 to 6, wherein the outer circumferential surfaces (21a, 22a) of the second tubes (21, 22) are not provided with a hydrophilic coating layer.

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