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 slide along a longitudinal direction of the first tube 11. A sliding load of an outer peripheral surface 21a of the second tube 21 is larger than that of the outer peripheral surface 11a of the first tube 11.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 and to apply pressure to the liquid, which requires a large-scale device and tends to make operation complicated.

[0008] An object of the present disclosure is to provide 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 slidable along the longitudinal axis of the first tube, the sliding load of the outer peripheral surface of the second tube being greater than the sliding load of the outer peripheral surface of the first tube. According to this configuration, excellent support and guidance can be obtained with a simple configuration.

[0010] (2) In the catheter of (1), The sliding load on the inner circumferential surface of the second tube may be smaller than the sliding load on the outer circumferential surface of the second tube. According to this configuration, the second tube can easily slide relative to the first tube.

[0011] (3) In the catheters of (1) and (2), the first tube includes a first hydrophilic coating layer; The outer circumferential surface of the first hydrophilic coating layer may form the outer circumferential surface of the first tube. According to this configuration, the first tube can be smoothly guided to the area to be supported.

[0012] (4) In the catheter of (1) to (3), the second tube includes a second hydrophilic coating layer; The outer circumferential surface of the second hydrophilic coating layer may form the outer circumferential surface of the second tube. According to this configuration, when the outer peripheral surface of the second tube comes into contact with the wall of the body cavity, it is possible to reduce irritation to the wall of the body cavity.

[0013] (5) In the catheter of (1) to (4), The second tube may have a length shorter than the length of the first tube. With this configuration, the operator can move the first tube toward the proximal end and expose the distal portion of the first tube from the distal end of the second tube, which allows the distal portion of the first tube to exhibit good flexibility, thereby providing excellent guidance for the catheter.

[0014] (6) In the catheter of (1) to (5), The proximal end of the first tube may be provided with a gripping member having an outer diameter larger than the 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.

[0015] 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 within 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. "Distal" refers to the distal end of any component. "Proximal end" refers to the proximal end of any component. "Proximal end" refers to the proximal end of any component. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic vertical cross-sectional view showing a first embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 2 is a schematic vertical cross-sectional view showing a first state in the first embodiment. [Figure 4] FIG. 4 is a schematic vertical cross-sectional view showing an example of a second state in the first embodiment. [Figure 5] FIG. 4 is a schematic vertical cross-sectional view showing an example of a second state in the first embodiment. [Figure 6] FIG. 2 is a schematic diagram showing an example of a first state during use. [Figure 7] FIG. 10 is a schematic diagram showing an example of a second state during use. [Figure 8] FIG. 10 is a schematic diagram showing an example of a medical device delivered in a second state during use. [Figure 9] FIG. 10 is a schematic enlarged longitudinal sectional view showing a part of the second embodiment. [Figure 10] FIG. 10 is a schematic cross-sectional view taken along line XX in FIG. 9. DETAILED DESCRIPTION OF THE INVENTION

[0017] 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 slidable along the longitudinal axis of the first tube, wherein the sliding load of the outer peripheral surface of the second tube is greater than the sliding load of the outer peripheral surface of the first tube.

[0018] 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.

[0019] In Figures 1, 3, 4, 5, and 9, 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.

[0020] [First embodiment] 1 to 5 are schematic diagrams showing a first embodiment. As shown in FIGS. 1 and 2, a catheter 1 includes a first tube 11, a second tube 21, and a gripping member 31.

[0021] The first tube 11 is a hollow member and has, for example, an inner cavity 11h that passes through in the longitudinal direction from an opening 11c at the tip end to the base end.

[0022] Since the first tube 11 is inserted into a body cavity, the material constituting the first tube 11 preferably has antithrombogenicity, flexibility, and biocompatibility. Examples of the material 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.

[0023] The second tube 21 is a hollow member. 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. 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 slidable 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. 2, the second tube 21 surrounds the entire first tube 11 in the circumferential direction.

[0024] The length of the second tube 21 in the longitudinal direction is not particularly limited. The length of the second tube 21 may be shorter than the length of the first tube 11, for example. The stiffness of the catheter 1 is high in the portion where the first tube 11 and the second tube 21 overlap, and is low in the portion where the first tube 11 and the second tube 21 do not overlap. The catheter 1 has a portion with high stiffness, which improves the support of the medical device by the catheter 1, and a portion with low stiffness, which improves the guideability of the catheter 1.

[0025] Since the material constituting the second tube 21 is inserted into a body cavity, it is preferable that it has antithrombogenicity and biocompatibility. Examples of the material constituting 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 made of a metal material, such as a hypotube, on the proximal side of the portion made of a resin material.

[0026] The sliding load of the outer peripheral surface 21a of the second tube 21 is greater than the sliding load of the outer peripheral surface 11a of the first tube 11. In other words, the frictional resistance between the outer peripheral surface 11a of the first tube 11 and the body cavity wall is smaller than the frictional resistance between the outer peripheral surface 21a of the second tube 21 and the body cavity wall.

[0027] The "sliding load" in the present disclosure can be measured, for example, using a friction tester. The sliding load is measured while the tube is wet with water. The friction tester may be, for example, an FTS6000 (manufactured by Harland Medical Systems, Inc.). When measuring the sliding load, the tester puts water into the water bath of the FTS6000 to wet the tube with water.

[0028] The sliding loads of the outer peripheral surfaces 11a, 21a of the first and second tubes can be adjusted, for example, by devising the surface physical properties, shape, etc. The sliding loads of the outer peripheral surfaces 11a, 21a of the first and second tubes can be adjusted, for example, by appropriately combining materials with different surface physical properties or by appropriately combining materials with different surface shapes.

[0029] In this embodiment, the first tube 11 and the second tube 21 are formed of the same material. The outer peripheral surface 11a of the first tube 11 is flatter than the outer peripheral surface 21a of the second tube 21, and the outer peripheral surface 21a of the second tube 21 is rougher than the outer peripheral surface 11a of the first tube 11. As a result, the sliding load of the outer peripheral surface 21a of the second tube 21 is greater than the sliding load of the outer peripheral surface 11a of the first tube 11.

[0030] The sliding load of the inner circumferential surface 21b of the second tube 21 may be smaller than the sliding load of the outer circumferential surface 21a of the second tube 21. In this embodiment, the outer circumferential surface 21a of the second tube 21 is rougher than the inner circumferential surface 21b of the second tube 21, and the inner circumferential surface 21b of the second tube 21 is flatter than the outer circumferential surface 21a of the second tube 21. This allows the second tube 21 to slide easily relative to the first tube 11.

[0031] The gripping member 31 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. In this embodiment, the gripping member 31 is connected to the base end of the first tube 11. The gripping member 31 has an outer diameter larger than the inner diameter of the second tube 21. This prevents the operator from pulling the second tube 21 out of the first tube 11 toward the base end. This results in a practical catheter 1 with excellent operability. The gripping member 31 has an opening 31a at its base end and an inner lumen 31h that communicates with the inner lumen 11h.

[0032] The inner cavities 11h and 31h form a lumen L. For example, a guide wire, a medical device, etc., is inserted through the lumen L.

[0033] The catheter 1 can be selectively switched between, for example, a first state and a second state described below by sliding the second tube 21 along the longitudinal direction of the first tube 11.

[0034] 3, the first state is a state in which the distal end of the second tube 21 is located closer to the proximal end than the distal end of the first tube 11, and the distal ends 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 distal end of the catheter 1 is exposed to the outside.

[0035] 4, 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. The second state may also be a state in which the entire outer peripheral surface 11a of the tip portion of the first tube 11 is covered with the second tube 21, as shown in FIG.

[0036] In the first state, the frictional resistance between the tip end portion of the catheter 1 and the body cavity wall is smaller than in the second state, and in the second state, the frictional resistance between the tip end portion of the catheter 1 and the body cavity wall is larger than in the first state.

[0037] A description will be given of a mode of use of the catheter, in which a procedure is performed using the catheter 1 to support the medical device D near the aortic arch.

[0038] First, a guide wire (not shown) is inserted into the blood vessel V, and its tip is delivered in advance to the site to be treated. Next, as shown in Figure 6, a guiding catheter E is advanced within the blood vessel V along the guide wire.

[0039] 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, the catheter 1 is advanced along the guide catheter E. Then, the guide catheter E is withdrawn from the body.

[0040] Next, the catheter 1 is switched to the second state. Specifically, as shown in Fig. 7, the second tube 21 is advanced along the first tube 11 while manipulating the proximal end of the second tube 21. In the use example of Fig. 7, the catheter 1 supports a medical device at the site where the descending aorta branches off into the right common carotid artery via the brachiocephalic trunk.

[0041] Next, as shown in Fig. 8, the medical device D is delivered along the catheter 1. While the medical device D is supported by the catheter 1, the medical device D is pushed forward to the site to be treated. Then, the treatment is performed using the medical device D. For example, a thrombus aspiration catheter is used as the medical device D to aspirate a thrombus in a blood vessel.

[0042] 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.

[0043] As described above, the catheter 1 has the above-described configuration, and thus can achieve excellent support and guidance with a simple configuration. For example, in the first state, the first tube 11, which has a small sliding load, can be smoothly guided. In the second state, a larger portion of the first tube 11 is supported by the second tube 21, which has a large sliding load. As a result, the catheter 1 is stably placed inside the blood vessel V. Therefore, the catheter 1 exhibits excellent support for the medical device D.

[0044] [Second embodiment] 9 and 10 are schematic diagrams showing a second embodiment. As shown in FIGS. 9 and 10, a catheter 2 includes a first tube 12, a second tube 22, and a gripping member 31 (not shown) (see FIG. 1). The catheter 2 differs from the first embodiment in that it includes the first tube 12 and the second tube 22. The configuration of the gripping member 31 is the same as that of the first embodiment. The configuration other than the configuration of the first tube 12 and the second tube 22 described below, and the manner of use of the catheter 2 are the same as those of the first embodiment, so detailed description thereof will be omitted.

[0045] The first tube 12 is a hollow member. The first tube 12 of this embodiment includes a first hydrophilic coating layer 121. The outer peripheral surface of the first hydrophilic coating layer 121 forms the outer peripheral surface 12a of the first tube 12. The first hydrophilic coating is exposed on the outer peripheral surface 12a of the first tube 12. Therefore, the first hydrophilic coating can be in direct contact with either the wall of the body cavity or the inner peripheral surface 22b of the second tube 22.

[0046] The second tube 22 is disposed so as to surround the outer circumferential surface 12a of the first tube 12, and is a member that can slide along the longitudinal direction of the first tube 12. The second tube 22 of this embodiment includes a second hydrophilic coating layer 221. The outer circumferential surface of the second hydrophilic coating layer 221 forms the outer circumferential surface 22a of the second tube 22. The second hydrophilic coating is exposed on the outer circumferential surface 22a of the second tube 22. Therefore, the second hydrophilic coating can directly contact the wall of the body cavity.

[0047] The materials constituting the first and second hydrophilic coating layers 121 and 221 preferably have 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. Two or more of the above materials may also be used in combination.

[0048] The portions of the first and second tubes 12 and 22 on which the first and second hydrophilic coating layers 121 and 221 are provided are not particularly limited. The portions may be a part of the longitudinal direction or the entire longitudinal direction. The portions may be divided into two or more independent portions.

[0049] As described above, the catheter 2 has the above-described configuration, and therefore can provide excellent support and guidance with a simple configuration.

[0050] The catheter 2 of this embodiment includes a first hydrophilic coating layer 121. Therefore, when the catheter 2 is inserted into a body cavity in the first state, the first tube 12 can be smoothly guided to the area to be supported. This is presumably because, since the first hydrophilic coating is exposed to the outside in the first state, the first hydrophilic coating layer 121 absorbs moisture within the body cavity upon contact with the body cavity wall, and as a result, the liquid film formed on the outer circumferential surface 12a of the first tube 12 enhances lubricity (reducing frictional resistance between the catheter 2 and the body cavity wall).

[0051] The catheter 2 of this embodiment includes the second hydrophilic coating layer 221. Therefore, when the outer peripheral surface 22a of the second tube 22 comes into contact with the body cavity wall, irritation to the body cavity wall can be reduced. This is presumably because the buffering effect of the liquid film formed on the outer peripheral surface 22a of the second tube 22 upon contact with the body cavity wall reduces the irritation that the second tube 22 imparts to the body cavity wall.

[0052] 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.

[0053] In the second embodiment described above, the catheter 2 is described in which the hydrophilic coating layers 121, 221 are provided on the first tube 12 and the second tube 22, respectively. However, when a hydrophilic coating layer is provided, it is sufficient that the hydrophilic coating layer is provided on at least one of the first tube and the second tube.

[0054] The first tubes 11, 12 and the second tubes 21, 22 may have a configuration in which multiple tube layers are stacked. A cylindrical reinforcing body may be provided inside the first tubes 11, 12 and the second tubes 21, 22 so as to surround the respective inner lumens. Examples of the reinforcing body include a coil body and a cylindrical mesh body.

Claims

1. a first tube (11, 12); a second tube (21, 22) arranged to surround an outer peripheral surface (11a, 12a) of the first tube (11, 12) and slidable along the longitudinal direction of the first tube (11, 12), wherein the sliding load of the outer peripheral surface (21a, 22a) of the second tube (21, 22) is greater than the sliding load of the outer peripheral surface (11a, 12a) of the first tube (11, 12).

2. The catheter (1, 2) according to claim 1, wherein the sliding load of the inner circumferential surface (21b, 22b) of the second tube (21, 22) is smaller than the sliding load of the outer circumferential surface (21a, 22a) of the second tube (21, 22).

3. the first tube (12) comprises a first hydrophilic coating layer (121); 3. The catheter (2) according to claim 1 or 2, wherein the outer surface of the first hydrophilic coating layer (121) forms the outer surface (12a) of the first tube (12).

4. the second tube (22) comprises a second hydrophilic coating layer (221); The catheter (2) according to any one of claims 1 to 3, wherein the outer surface of the second hydrophilic coating layer (221) forms the outer surface (22a) of the second tube (22).

5. 5. The catheter (1, 2) according to any one of claims 1 to 4, wherein the length of the second tube (21, 22) is shorter than the length of the first tube (11, 12).

6. A catheter (1, 2) as described in any one of claims 1 to 5, wherein a gripping member (31) having an outer diameter larger than the inner diameter of the second tube (21, 22) is provided at the proximal end of the first tube (11, 12).

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