WO2025028185A1 - Catheter - Google Patents

Abstract

Provided is a catheter in which the tip of a distal-end part is less likely to detach. This catheter has a first cylindrical member that extends in the longitudinal direction, a second cylindrical member that extends in the longitudinal direction and is adjacent to the first cylindrical member in the radial direction, an outer member that extends in the longitudinal direction and has a portion encompassing at least part of the first cylindrical member and at least part of the second cylindrical member, and a tip that is disposed at a distal-end part of the second cylindrical member and extends in the longitudinal direction, wherein the distal end of the first cylindrical member is positioned closer to the proximal side than the distal end of the second cylindrical member, the proximal end of the first cylindrical member is positioned closer to the proximal side than the proximal end of the second cylindrical member, the tip has a protrusion that protrudes in a direction away from the central axis of the tip, and the outer member covers at least part of the protrusion.

Description

catheter

The present invention relates to a catheter.

Catheters that can be inserted into blood vessels, etc., are used to examine and treat lesions in the human body. For example, Patent Document 1 describes such a catheter, which includes a catheter body having a hollow coil body formed by winding or twisting together a plurality of metal wires, at least one of which has a diameter larger than the diameters of the other wires, an inner resin layer that covers the inner circumferential surface of the coil body, and an outer resin layer that covers the outer circumferential surface of the coil body in a substantially circular shape without exposing the outer surface of the larger-diameter wire of the coil body to the outside, and a resin tubular body provided at the distal end of the catheter body, with an inner hole that communicates with the hollow portion of the catheter body. The catheter is characterized by including a tip, an inner layer extension part in which the inner resin layer extends integrally from the distal end of the catheter body toward the tip side to form the inner peripheral part of the proximal end of the tip, and a braided body made by braiding multiple wires arranged in the inner layer extension part within the tip and in the inner resin layer of at least the distal end part of the catheter body, positioned so as to extend in the axial direction across the boundary between the proximal end of the tip and the distal end of the catheter body.

JP 2011-125737 A

　In conventional catheters, tips placed at the distal end could become detached when the catheter was inserted into the body or removed. The present invention was made in consideration of the above circumstances, and its purpose is to provide a catheter whose tip at the distal end is less likely to become detached.

A catheter according to an embodiment of the present invention that can solve the above problems is as follows.
[1] A first tubular member extending in a longitudinal direction;
a second cylindrical member extending in the longitudinal direction and adjacent to the first cylindrical member in a radial direction;
an outer member having a portion extending in the longitudinal direction and including at least a portion of the first tubular member and at least a portion of the second tubular member;
a longitudinally extending tip disposed at a distal end of the second tubular member,
a distal end of the first tubular member is located proximal to a distal end of the second tubular member;
a proximal end of the first tubular member is located proximal to a proximal end of the second tubular member;
A catheter in which the tip has a protrusion protruding in a direction away from a central axis of the tip, and the outer member covers at least a portion of the protrusion.

As described above, the protrusion that protrudes away from the central axis of the tip is covered by the outer member, making it difficult for the tip located at the distal end to become detached from the catheter.

Furthermore, the catheter according to the embodiment is preferably any one of the following [2] to [15].
[2] A catheter as described in [1], wherein the distal end of the outer member is located distal to a thickest portion, which is the thickest part of the protrusion.
[3] A catheter as described in [1], wherein the distal end of the outer member is located distal to the distal end of the protrusion.
[4] A catheter described in any of [1] to [3], wherein the distal end of the outer member is located proximal to the distal end of the second tubular member.
[5] A catheter described in any of [1] to [4], wherein the protrusion is located at the proximal end of the tip.
[6] A catheter described in any of [1] to [5], wherein the tip has, in the radial direction, a first region closer to the first tubular member and a second region farther from the first tubular member, and the first region has the protrusion.
[7] A catheter described in any one of [1] to [6], wherein the tip is fixed to the second tubular member and not fixed to the outer member.
[8] A catheter described in any one of [1] to [7], wherein the tip has metal powder at least on its outer surface that is covered by the outer member.
[9] A catheter described in any of [1] to [8], wherein the tip has an inner cavity extending in the longitudinal direction, and at least the distal end of the second tubular member is disposed within the inner cavity.
[10] A catheter as described in [9], wherein the diameter of the inner cavity of the tip distal to the distal end of the second tubular member is greater than or the same length as the inner diameter of the second tubular member at the distal end of the second tubular member.
[11] The tip includes a first thin portion located distal to the protrusion and thinner than the protrusion;
The catheter according to any one of [1] to [10], further comprising a first thick-walled portion located distal to the first thin-walled portion and thicker than the first thin-walled portion.
[12] A catheter described in any of [1] to [11], wherein the outer member is tubular and has an inner cavity extending in the longitudinal direction, and at least a portion of the first tubular member and at least a portion of the second tubular member are disposed in the inner cavity.
[13] The outer member has a columnar body extending in the longitudinal direction and containing a resin,
The catheter according to any one of [1] to [11], wherein at least a portion of the first tubular member and at least a portion of the second tubular member are disposed within the cylindrical body.
[14] A catheter described in any one of [1] to [13], wherein the first tubular member and the second tubular member are fixed to each other in the radial direction.
[15] A catheter described in any one of [1] to [14], wherein a handle portion is disposed at the proximal end of the first tubular member.

The present invention provides a catheter with the above configuration, in which the tip at the distal end is less likely to come off.

FIG. 1 is a side view of a catheter according to a first embodiment. FIG. 2 is a longitudinal cross-sectional view of region R1 in FIG. FIG. 3 is a longitudinal cross-sectional view of region R2 in FIG. FIG. 4 is a longitudinal cross-sectional view of a modification of the region R1 of FIG. FIG. 5 is a longitudinal cross-sectional view of another modification of the region R1 of FIG. FIG. 6 is a cross-sectional view of the catheter of FIG. 1 taken along line AA. FIG. 7 is a side view of the catheter according to the second embodiment. FIG. 8 is a longitudinal cross-sectional view of region R1 in FIG. FIG. 9 is a longitudinal cross-sectional view of region R2 in FIG. FIG. 10 is a cross-sectional view of the catheter of FIG. 7 taken along line AA.

The present invention will be described in more detail below based on the following embodiment, but the present invention is of course not limited to the following embodiment, and can of course be implemented with appropriate modifications within the scope of the intent described above and below, all of which are included in the technical scope of the present invention. Note that in each drawing, component reference numbers may be omitted for convenience, but in such cases, reference should be made to the specification or other drawings. Furthermore, the dimensions of various components in the drawings may differ from the actual dimensions, as priority is given to contributing to an understanding of the features of the present invention.

The catheter according to the embodiment has a first tubular member extending in the longitudinal direction, a second tubular member extending in the longitudinal direction and radially adjacent to the first tubular member, an outer member extending in the longitudinal direction and having a portion that contains at least a portion of the first tubular member and at least a portion of the second tubular member, and a tip extending in the longitudinal direction and disposed at the distal end of the second tubular member, wherein the distal end of the first tubular member is located proximal to the distal end of the second tubular member, the proximal end of the first tubular member is located proximal to the proximal end of the second tubular member, the tip has a protruding portion that protrudes in a direction away from the central axis of the tip, and the outer member covers at least a portion of the protruding portion.

As described above, the protrusion that protrudes away from the central axis of the tip is covered by the outer member, making it difficult for the tip located at the distal end to become detached from the catheter.

Below, a catheter according to a first embodiment will be described with reference to Figs. 1 to 6. Fig. 1 is a side view of a catheter according to an embodiment. Fig. 2 is a longitudinal cross-sectional view of region R1 in Fig. 1. Fig. 3 is a longitudinal cross-sectional view of region R2 in Fig. 1. Fig. 4 is a longitudinal cross-sectional view of a modified example of region R1 in Fig. 1. Fig. 5 is a longitudinal cross-sectional view of another modified example of region R1 in Fig. 1. Fig. 6 is an A-A cross-sectional view of the catheter in Fig. 1.

1, 2, and 3, the catheter 91 according to the first embodiment has a first tubular member 1 extending in the longitudinal direction X, and a second tubular member 2 extending in the longitudinal direction X and adjacent to the first tubular member 1 in the radial direction Y. Specifically, it is preferable that the outer surface of the first tubular member 1 and the outer surface of the second tubular member 2 are adjacent to each other in the radial direction Y. It is preferable that the first tubular member 1 has an inner lumen 1L extending in the longitudinal direction X. It is preferable that the second tubular member 2 has an inner lumen 2L extending in the longitudinal direction X. By inserting, for example, a guide wire into each of the lumen 1L and the lumen 2L, the catheter 91 can be guided in multiple directions, making it easier to insert the catheter 91 into various branching parts of the coronary artery, for example. In addition, it is easier to search for the entrance of a stenosis, which is a lesion, by inserting a searching wire into the lumen 1L or the lumen 2L. Of these, it is preferable to insert a searching wire into the lumen 1L. The tip of the search wire may be bent.

2, the catheter 91 further includes an outer member 3 extending in the longitudinal direction X and having a portion that contains at least a part of the first tubular member 1 and at least a part of the second tubular member 2, and a tip 7 extending in the longitudinal direction X and disposed at the distal end 2b of the second tubular member 2. The tip 7 has a protruding portion 7P that protrudes in a direction away from the central axis 7C of the tip 7, and the outer member 3 covers at least a part of the protruding portion 7P. Because the protruding portion 7P is covered by the outer member 3, the tip 7 is less likely to detach from the second tubular member 2. Examples of the shape of the protruding portion 7P include a cone, a polygonal pyramid, a rounded polygonal pyramid, a truncated cone, a truncated polygonal pyramid, a rounded polygonal pyramid, a hemisphere, a semi-elliptical sphere, or a combination of these shapes. The shape of the outer edge of the tip 7 in a cross section in the radial direction Y including the protruding portion 7P of the tip 7 is preferably circular or elliptical. This makes it easier to insert the tip 7 into the body. The tip 7 may have multiple protrusions 7P, but it is preferable that the tip 7 has only one protrusion 7P. The shape of the outer edge of the tip 7 in a cross section in the radial direction Y of the portion of the tip 7 that does not include the protrusion 7P is preferably circular or elliptical. This makes it easier to insert the tip 7 into the body.

The protrusion 7P is preferably located at the proximal end 7a of the tip 7. This makes it even more difficult for the tip 7 to detach from the second tubular member 2. The protrusion 7P is preferably adjacent to the proximal end 7A of the tip 7. In addition, the distal end 7PB of the protrusion 7P is preferably located proximal to the midpoint of the central axis 7C of the tip 7.

The tip 7 has a first region 71 closer to the first tubular member 1 in the radial direction Y, and a second region 72 farther from the first tubular member 1, and it is preferable that the first region 71 has a protrusion 7P. The side of the tip 7 closer to the first tubular member 1 in the radial direction Y is a portion that is less likely to come into contact with body tissue due to the length of the diameter of the first tubular member 1, so by locating the protrusion 7P in the first region 71, the protrusion 7P is less likely to come into contact with body tissue. As a result, the tip 7 can be easily and smoothly inserted into the body.

2, when the cross section X is a cross section in the longitudinal direction X including the central axis 1C of the first tubular member 1 and the central axis 2C of the second tubular member 2, it is preferable that the protruding portion 7P has a proximal side inclined portion that is inclined away from the central axis 7C of the tip 7 as it moves toward the distal side, and a distal side inclined portion that is located distal to the proximal side inclined portion and is inclined toward the central axis 7C of the tip 7 as it moves toward the distal side. The distal side inclined portion makes it easier to insert the tip 7 into the body. The proximal side inclined portion makes it possible to increase the contact area between the tip 7 and the outer member 3. The shape of the outer surface of the proximal side inclined portion and the distal side inclined portion in the cross section X is preferably linear or curved, and more preferably linear. For example, when the outer surface of the distal side inclined portion in the cross section X is linear, the shape of the distal side inclined portion is a so-called tapered shape.

The tip 7 is preferably fixed to the second tubular member 2. This makes it even more difficult for the tip 7 to detach from the second tubular member 2. Specifically, at least a portion of the inner surface of the tip 7 is preferably fixed to the outer surface of the second tubular member 2. Examples of the manner of fixing include welding and adhesion. Although not shown, another layer may be disposed between the tip 7 and the second tubular member 2, and the tip 7, the other layer, and the second tubular member 2 may be welded or glued together.

It is preferable that the tip 7 is not fixed to the outer member 3. This makes it difficult for external forces acting on the outer member 3 near the protrusion 7P to act on the protrusion 7P, making it difficult to avoid the tip 7 becoming detached due to external forces.

On the other hand, the tip 7 may be fixed to the outer member 3. In this way, even if the tip 7 and the second tubular member 2 are separated by, for example, an external force, the outer member 3 can prevent the tip 7 from detaching from the second tubular member 2. Specifically, at least a part of the outer surface of the tip 7 may be fixed to the inner surface of the outer member 3. Examples of the manner of fixing include welding and adhesion. Although not shown, another layer may be disposed between the tip 7 and the outer member 3, and the tip 7, the other layer, and the outer member 3 may be welded or adhered together.

The tip 7 preferably has metal powder at least on the outer surface covered by the outer member 3. This allows unevenness to be formed on the outer surface of the tip 7, improving friction when the tip 7 and the outer member 3 are not fixed to each other, and improving fixing force when the tip 7 and the outer member 3 are fixed to each other. As a result, the tip 7 is less likely to come off. An example of the metal powder is tungsten powder. Powder of an X-ray opaque material, which will be described later, may also be used as the metal powder.

The tip 7 preferably contains a flexible resin. This can reduce damage to internal tissues caused by inserting the tip 7 into the body. The flexible resin preferably contains at least one selected from the group consisting of polyethylene, polyurethane, polyurethane-based thermoplastic elastomer, styrene-based thermoplastic elastomer, polyamide elastomer, and polyamide, and more preferably contains at least one selected from the group consisting of polyurethane and polyamide elastomer. The polyethylene is preferably a low-density polyethylene with a specific gravity of 0.91 to 0.92.

The tip 7 preferably contains a flexible resin and metal powder, and more preferably contains a mixture of flexible resin and metal powder. For example, when an X-ray opaque material is used as the metal powder, the X-ray opaque material is dispersed in the flexible resin, which makes the tip 7 more likely to exhibit X-ray opaqueness, making it easier to observe from outside the body.

The tip 7 has an inner cavity 7L extending in the longitudinal direction X, and it is preferable that at least the distal end 2B of the second tubular member 2 is disposed within the inner cavity 7L. This allows at least a portion of the inner surface of the tip 7 to be fixed to the outer surface of the second tubular member 2. In the cross section of the tip 7 in the radial direction Y, it is preferable that the shape of the inner cavity 7L is circular or elliptical. This makes it easier to fix at least a portion of the inner surface of the tip 7 to the outer surface of the second tubular member 2.

The diameter of the lumen 7L of the tip 7 distal to the distal end 2B of the second tubular member 2 is preferably larger than or the same as the inner diameter of the second tubular member 2 at the distal end 2B of the second tubular member 2. As shown in FIG. 2, having these the same length allows the guidewire to be smoothly inserted into the second tubular member 2. On the other hand, as shown in FIG. 4, the diameter of the lumen 7L distal to the distal end 2B is larger than the inner diameter of the second tubular member 2 at the distal end 2B, so that when the guidewire is inserted into the lumen 7L, the inner surface of the tip 7 is less likely to come into contact with the guidewire, making it easier to prevent the tip 7 from coming off due to friction with the guidewire.

The tip 7 preferably has a first thin portion 7U1 located distal to the protruding portion 7P and thinner than the protruding portion 7P, and a first thick portion 7T1 located distal to the first thin portion 7U1 and thicker than the first thin portion 7U1. This allows the tip 7 to bend around the first thin portion 7U1 when inserted into a curved portion such as a blood vessel inside the body, and the first thick portion 7T1 makes it easier to prevent the tip 7 from bending excessively.

The distal end 7B of the tip 7 is preferably located distal to the distal end 2B of the second tubular member 2. By positioning the tip 7 made of a flexible material in this manner, the flexibility of the portion distal to the distal end 2B of the second tubular member 2 can be improved. The portion of the tip 7 distal to the distal end 2B of the second tubular member 2 preferably includes the first thick portion 7T1, and more preferably consists of the first thick portion 7T1.

As shown in FIG. 2, as described above, the catheter 91 further has an outer member 3 that extends in the longitudinal direction X and has a portion that contains at least a portion of the first tubular member 1 and at least a portion of the second tubular member 2. The outer member 3 can protect the first tubular member 1 and the second tubular member 2, and can also make it easier to prevent the guidewire from breaking through from inside the catheter 91.

2, 3, and 6, in the catheter 91, the outer member 3 is cylindrical and has a lumen 3L extending in the longitudinal direction X, and it is preferable that at least a part of the first cylindrical member 1 and at least a part of the second cylindrical member 2 are disposed in the lumen 3L. This makes it possible to protect the first cylindrical member 1 and the second cylindrical member 2, and the gap between the outer member 3 and the first cylindrical member 1 and the gap between the outer member 3 and the second cylindrical member 2 allow each cylindrical member to move to a certain extent, so that the force of the guide wire from inside the catheter 92 can be released, and as a result, it is possible to easily prevent the guide wire from breaking through. It is preferable that the distal end of the cylindrical outer member 3 is fixed to the first cylindrical member 1 and the second cylindrical member 2. It is preferable that the proximal end of the cylindrical outer member 3 is fixed to the first cylindrical member 1 and the second cylindrical member 2. This makes it difficult for the cylindrical outer member 3 to twist or twist.

The outer member 3 preferably contains at least one selected from the group consisting of polyethylene, polyurethane, polyurethane-based thermoplastic elastomer, styrene-based thermoplastic elastomer, polyamide elastomer, and polyamide. Of these, at least one selected from the group consisting of polyurethane and polyamide elastomer is more preferable.

The distal end 3B of the outer member 3 is preferably located distal to the thickest part 7PT, which is the thickest part of the protrusion 7P. This makes it even more difficult for the tip 7 to detach from the second tubular member 2.

The distal end 3B of the outer member 3 is preferably located distal to the distal end 7PB of the protrusion 7P. This makes it even more difficult for the tip 7 to detach from the second tubular member 2.

The distal end 3B of the outer member 3 is preferably located closer to the proximal side than the distal end 2B of the second tubular member 2. This makes it easier to insert the tip 7 into the body.

The first tubular member 1 and the second tubular member 2 each preferably have one or more layers extending in the longitudinal direction X, and more preferably have multiple layers. The multiple layers preferably have an inner layer and an outer layer that contains at least a part of the inner layer. The multiple layers may further have an intermediate layer located between the inner layer and the outer layer. The number of intermediate layers is not limited to one, and may be two or more. It is preferable that each of the multiple layers contains a material different from that of the adjacent layer. The inner layer of the first tubular member 1 and the inner layer of the second tubular member 2 each preferably contain at least one resin selected from the group consisting of polyolefin resins and fluorine-based resins. This can improve the sliding properties of the guide wire inserted into the lumen 1L and the lumen 2L. The polyolefin resin is preferably polyethylene, polypropylene, an ethylene-propylene copolymer, or a mixture thereof. The polyethylene is preferably high-density polyethylene with a specific gravity of 0.942 or more. The fluororesin is preferably polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkylvinylether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, polyvinylidene fluoride, polychlorotrifluoroethylene, ethylene-chlorotrifluoroethylene copolymer, or a mixture thereof. The inner layer of the first cylindrical member 1 and the inner layer of the second cylindrical member 2 may each contain at least one selected from the group consisting of polyamide resin, polyester resin, polyurethane resin, polyolefin resin, fluorine resin, vinyl chloride resin, silicone resin, and natural rubber. The inner layer of the first cylindrical member 1 and the inner layer of the second cylindrical member 2 may contain different resins, preferably the same resin, and more preferably the same resin.

The outer layer of the first tubular member 1 and the outer layer of the second tubular member 2 each preferably contain a flexible resin. The flexibility of the catheter 91 is improved by the outer layers containing a flexible resin. The flexible resin preferably contains at least one type selected from the group consisting of polyethylene, polyurethane, polyurethane-based thermoplastic elastomer, styrene-based thermoplastic elastomer, polyamide elastomer, and polyamide, and more preferably contains at least one type selected from the group consisting of polyurethane and polyamide elastomer. The polyethylene is preferably a low-density polyethylene with a specific gravity of 0.91 to 0.92.

The Shore D hardness of the material of the outer layer is preferably less than or equal to the Shore D hardness of the material of the inner layer, and preferably less. This makes the catheter 91 easier to bend. The Shore D hardness may be measured, for example, using a durometer type D in accordance with ISO 7619.

The intermediate layer preferably contains a different material than the inner or outer layer, but may contain the same material as the inner or outer layer.

The inner layer, intermediate layer, and outer layer are preferably fixed to the adjacent layers. This makes it difficult for each layer to twist or kink. Examples of the manner of fixing include welding and adhesion. Although not shown, a reinforcing member may be disposed as an intermediate layer. Talc may also be disposed between the tip 7 and the second tubular member 2 and/or between the tip 7 and the outer member 3. This reduces the tackiness of the surface of the tip 7, making it easier to insert the second tubular member 2 into the tip 7 during manufacture. This also makes it easier to cover the tip 7 with the outer member 3.

The first tubular member 1 is preferably provided with a reinforcing member. This makes it easier to prevent the wire from breaking through the first tubular member 1. On the other hand, the second tubular member 2 is preferably not provided with a reinforcing member. This makes it easier to improve the flexibility of the second tubular member 2.

The reinforcing member is preferably a braided body in which wire is braided, a coil body in which wire is wound in a spiral shape, or a combination of these. This makes it easier to prevent the guide wire from breaking through the first tubular member 1. Of these, the braided body is more preferably the reinforcing member because it is easier to improve the rigidity. Examples of wires contained in the reinforcing member include metal wires and fibers. The metal wire preferably contains stainless steel, titanium, nickel-titanium alloy, cobalt-chromium alloy, tungsten alloy, or an alloy thereof. Of these, stainless steel is more preferable. The metal wire may be a single wire or a twisted wire. The fiber is preferably polyarylate fiber, aramid fiber, ultra-high molecular weight polyethylene fiber, PBO fiber, carbon fiber, or a mixture of these fibers. The fiber may be a monofilament or a multifilament. The reinforcing member may contain an X-ray opaque material to make it easier to confirm the position of the first tubular member 1 under X-ray fluoroscopy, etc. The radiopaque material is preferably at least one selected from the group consisting of lead, barium, iodine, tungsten, gold, platinum, iridium, platinum-iridium alloy, stainless steel, titanium, cobalt-chromium alloy, palladium, bismuth, and tantalum.

Although not shown, the distal end of the reinforcing member is preferably located closer to the proximal end of the first opening 1E and more preferably closer to the distal end of the proximal end 2A of the second tubular member 2. On the other hand, the proximal end of the reinforcing member is preferably located closer to the proximal end 2A of the second tubular member 2, and more preferably located within the handle portion 8. This makes it easier to prevent the guidewire from breaking through the first tubular member 1.

The length in the longitudinal direction X from the distal end 2B of the second tubular member 2 to the proximal end 7A of the tip 7 is preferably longer than the length in the longitudinal direction X from the distal end 2B of the second tubular member 2 to the distal end 7B of the tip 7. This increases the contact area between the second tubular member 2 and the tip 7, making the tip 7 even more difficult to detach.

As shown in FIG. 2, the distal end 1B of the first tubular member 1 is located proximal to the distal end 2B of the second tubular member 2. This makes it easier for the catheter 91 to bend in the portion distal to the distal end 1B of the first tubular member 1, making it easier to insert into a curved portion such as a blood vessel inside the body.

As shown in Figures 1 and 3, the proximal end 1A of the first tubular member 1 is located proximal to the proximal end 2A of the second tubular member 2. This allows the portion of the catheter 91 proximal to the proximal end 2A of the second tubular member 2 to have a structure, for example a double tube structure (coaxial structure), which is different from the structure in which the first tubular member 1 and the second tubular member 2 distal to the proximal end 2A of the second tubular member 2 overlap in the radial direction Y, allowing different functions to be achieved.

2, the outer member 3 preferably has a protuberance 31 protruding away from the central axis 2C on the side closer to the first tubular member 1 in the radial direction Y than the distal end 1B of the first tubular member 1. This allows the tip of the wire inserted into the first tubular member 1 to be guided in a different direction from the tip of the wire inserted into the second tubular member 2, making it easier to treat bifurcation lesions, etc. This also makes it harder for the wires to become entangled. The protuberance 31 is preferably adjacent to the distal end 1B of the first tubular member 1. This makes it easier to guide the wire coming out of the first opening 1E by the protuberance 31. The outer member 3 at the protuberance 31 is preferably thicker than the outer member 3 around the protuberance 31.

2, when the cross section X is a cross section in the longitudinal direction X including the central axis 1C of the first tubular member 1 and the central axis 2C of the second tubular member 2, it is preferable that the protuberance 31 has a first inclined portion inclined in a direction away from the central axis 2C as it approaches the distal side, and a second inclined portion inclined so as to approach the central axis 2C as it approaches the distal side. It is preferable that the second inclined portion is located more distal than the first inclined portion. The first inclined portion makes it easier to guide the wire coming out of the first opening 1E. The second inclined portion makes it easier to insert into the body. The shape of the outer surface of the first inclined portion and the second inclined portion in the cross section X is preferably linear or curved, and more preferably linear. When the outer surface of the second inclined portion in the cross section X is linear, the shape of the second inclined portion is a so-called tapered shape.

On the other hand, as shown in FIG. 5, the outer member 3 may not have a protuberance that protrudes away from the central axis 2C on the side distal to the distal end 1B of the first tubular member 1 and closer to the first tubular member 1 in the radial direction Y. In this case, the protrusion 7P of the tip 7 can function as a protuberance to guide the wire.

As shown in FIG. 6, the first tubular member 1 and the second tubular member 2 are preferably fixed to each other in the radial direction Y. Specifically, the outer surface of the first tubular member 1 and the outer surface of the second tubular member 2 are preferably fixed to each other in the radial direction Y. This makes the second tubular member 2 less likely to twist or twist. Examples of the fixing method include welding and adhesion. As shown in FIG. 6, in the cross section of the catheter 91 in the radial direction Y, the shapes of the first lumen 1L and the second lumen 2L are preferably circular, elliptical, arched, or a combination of these, and more preferably circular or elliptical. This makes the catheter 91 more likely to bend. In the catheter 91, it is preferable that the first lumen 1L and the second lumen 2L are not connected to each other. In the cross section of the radial direction Y, the first lumen 1L may have a larger area than the second lumen 2L, may have a smaller area than the second lumen 2L, or may have the same area as the second lumen 2L.

As shown in FIG. 2, the first tubular member 1 preferably has a first opening 1E that communicates with the lumen 1L. The first opening 1E can be used as an entrance or exit for the guidewire.

As shown in FIG. 2, the second tubular member 2 preferably has a second opening 2E that communicates with the lumen 2L. The second opening 2E can be used as an entrance or exit for the guidewire.

As shown in FIG. 1, a handle portion 8 is preferably disposed at the proximal end 1a of the first tubular member 1. Specifically, the proximal end 1a of the first tubular member 1 is preferably disposed within the handle portion 8. The practitioner can insert the catheter 91 into the body by grasping and pushing the handle portion 8. The outer shape of the handle portion 8 may be such that the practitioner can grasp it with his/her fingers. The handle portion 8 is preferably a resin molded product obtained by injection molding or the like. Examples of resins include polyolefin resins such as polyethylene and polypropylene, polycarbonate resins, and (meth)acrylic resins. Of these resins, transparent resins such as polycarbonate and polymethyl methacrylate are preferred. This makes it easier to see inside the handle portion 8, making it easier to insert the wire.

The proximal end 1A of the first tubular member 1 is preferably located within the handle portion 8. This improves pushability.

The handle portion 8 preferably has an inner cavity that communicates with the inner cavity 1L of the first tubular member 1 and extends in the longitudinal direction X, and a guidewire can be inserted through this inner cavity.

1 and 3, the catheter 91 preferably further has an outer tubular member 4 extending in the longitudinal direction X. The outer tubular member 4 preferably has an inner lumen 4L extending in the longitudinal direction X, and a part of the first tubular member 1 is preferably disposed in the inner lumen 4L. The outer tubular member 4 can form a double tube structure (coaxial structure), which can improve the transmission of the pushing force while protecting the first tubular member 1. Specifically, the outer tubular member 4 preferably has a fixed portion fixed to the first tubular member 1 at the distal end, and a non-fixed portion not fixed to the first tubular member 1 on the proximal side of the fixed portion. In addition, the outer tubular member 4 preferably has a fixed portion fixed to the handle portion 8 at the proximal end.

The outer tubular member 4 is preferably located proximal to the proximal end 2A of the second tubular member 2. This allows the outer diameter of the outer tubular member 4 to be reduced.

The outer tubular member 4 preferably contains the same resin as the outer member 3 or a harder resin, and more preferably is made of a harder resin. A harder resin can improve pushability. In addition, the distal end of the outer tubular member 4 and the proximal end of the outer member 3 are preferably fixed to each other.

As shown in FIG. 2, the first tubular member 1 may have an X-ray opaque marker 6A proximal to the proximal end of the first opening 1E and distal to a point 1 cm proximally away from the proximal end of the first opening 1E. This makes it easier to grasp the position of the first opening 1E.

The second tubular member 2 may have an X-ray opaque marker 6B at a position distal to the proximal end 7A of the tip 7 and proximal to the distal end 7B of the tip 7. This makes it easier to grasp the position of the tip 7 when inserting it into a curved part inside the body, for example, and therefore easier to insert.

The radiopaque markers 6A and 6B are preferably ring-shaped. The radiopaque markers 6A and 6B each preferably contain a radiopaque material, and more preferably are made of a radiopaque material. The radiopaque material is preferably at least one selected from the group consisting of lead, barium, iodine, tungsten, gold, platinum, iridium, platinum-iridium alloy, stainless steel, titanium, cobalt-chromium alloy, palladium, bismuth, and tantalum.

Although not shown, the catheter 91 preferably further has a linear member extending in the longitudinal direction X and at least a portion of which is disposed within the outer cylindrical member 4. This can improve the transmission of the pushing force. The linear member is preferably straight. There may be one linear member, or two or more linear members. The proximal end of the linear member is preferably located within the handle portion 8. The distal end of the linear member is preferably located within the outer cylindrical member 4 or the outer member 3. The linear member is preferably a solid member without an internal cavity. The linear member preferably contains a metal, and more preferably is made of a metal. The metal is preferably stainless steel, nickel titanium, cobalt chrome, or an alloy thereof. The linear member preferably has a fixed portion extending in the longitudinal direction X and having the same radial cross-sectional shape. The linear member more preferably has a tapered portion located distal to the fixed portion and tapered toward the distal side.

The catheter 91 can be preferably used to treat narrowing or dilating blocked areas of blood vessels and other passageways in the body, and can be preferably used in performing coronary intervention (PCI) for lesions at the bifurcation of coronary arteries, etc.

Below, a catheter according to the second embodiment will be described with reference to Figures 7 to 10. Figure 7 is a side view of a catheter according to the second embodiment. Figure 8 is a longitudinal cross-sectional view of region R1 in Figure 7. Figure 9 is a longitudinal cross-sectional view of region R2 in Figure 7. Figure 10 is a cross-sectional view taken along line A-A of the catheter in Figure 7. A detailed description of portions of the catheter according to the second embodiment that overlap with the catheter according to the first embodiment will be omitted.

The catheter according to the second embodiment is a catheter 92 having a first tubular member 1 extending in the longitudinal direction X, a second tubular member 2 extending in the longitudinal direction X and adjacent to the first tubular member 1 in the radial direction Y, and an outer member 3 extending in the longitudinal direction X and having a portion that contains at least a portion of the first tubular member 1 and at least a portion of the second tubular member 2. For details of each part, please refer to the description of the catheter 91.

As shown in FIG. 7, in the catheter 92, the outer member 3 preferably has a columnar body 5 extending in the longitudinal direction X and containing resin, and at least a part of the first tubular member 1 and at least a part of the second tubular member 2 are preferably disposed within the columnar body 5. That is, at least a part of the first tubular member 1 and the second tubular member 2 are preferably sealed by the columnar body 5 extending in the longitudinal direction X and containing resin. This makes it easier to maintain the shapes of the lumen 1L and the lumen 2L extending in the longitudinal direction X even if the catheter 92 is curved. The columnar body 5 is preferably disposed at least between the proximal end 2A of the second tubular member 2 and the distal end 3B of the outer member 3. Note that the resin of the columnar body 5 may be present between the first tubular member 1 and the second tubular member 2.

The shape of the cylinder 5 is preferably a cylindrical, elliptical, or rounded polygonal cylinder, and more preferably a cylindrical or elliptical cylinder. This makes it easier to insert the catheter 92 into the body.

The column 5 may be formed by covering the first tubular member 1 and the second tubular member 2 stacked in the radial direction Y with a resin tube and heating and fusing them together, or the column 5 may be formed by injection molding the first tubular member 1 and the second tubular member 2 stacked in the radial direction Y.

It is preferable that at least a portion of the inner surface of the outer member 3 is fixed to the outer surfaces of the first tubular member 1 and the second tubular member 2. This makes it difficult for the outer member 3 to twist or twist. Examples of the manner of fixing include welding, adhesion, etc.

This application claims the benefit of priority based on Japanese Patent Application No. 2023-125556, filed on August 1, 2023. The entire contents of the specification of Japanese Patent Application No. 2023-125556, filed on August 1, 2023, are incorporated by reference into this application.

1 First cylindrical member 1a Proximal end 1A Proximal end 1B Distal end 1C Central axis 1E First opening 1L Lumen 2 Second cylindrical member 2A Proximal end 2B Distal end 2b Distal end 2C Central axis 2E Second opening 2L Lumen 3 Outer member 3B Distal end 3L Lumen 4 Outer cylindrical member 4L Lumen 5 Pillars 6A, 6B X-ray opaque marker 7 Chip 7a Proximal end 7A Proximal end 7B Distal end 7C Central axis 7L Lumen 7P Projection 7PB Distal end 7PT Thickest part 7U1 First thin part 7T1 First thick part 8 Handle part 31 Raised portion 71 First region 72 Second region 91, 92 Catheter X: Longitudinal direction Y: Radial direction

Claims (15)

A first tubular member extending in a longitudinal direction;
a second cylindrical member extending in the longitudinal direction and adjacent to the first cylindrical member in a radial direction;
an outer member having a portion extending in the longitudinal direction and including at least a portion of the first tubular member and at least a portion of the second tubular member;
a longitudinally extending tip disposed at a distal end of the second tubular member,
a distal end of the first tubular member is located proximal to a distal end of the second tubular member;
a proximal end of the first tubular member is located proximal to a proximal end of the second tubular member;
A catheter in which the tip has a protrusion protruding in a direction away from a central axis of the tip, and the outer member covers at least a portion of the protrusion. The catheter according to claim 1, wherein the distal end of the outer member is located distal to the thickest part of the protrusion. The catheter of claim 1, wherein the distal end of the outer member is located distal to the distal end of the protrusion. The catheter according to claim 1, wherein the distal end of the outer member is located proximal to the distal end of the second tubular member. The catheter of claim 1, wherein the protrusion is located at the proximal end of the tip. The catheter according to claim 1, wherein the tip has a first region closer to the first tubular member in the radial direction and a second region farther from the first tubular member, and the first region has the protrusion. The catheter of claim 1, wherein the tip is fixed to the second tubular member and not fixed to the outer member. The catheter according to claim 7, wherein the tip has metal powder at least on the outer surface that is covered by the outer member. The catheter according to claim 1, wherein the tip has an inner cavity extending in the longitudinal direction, and at least the distal end of the second tubular member is disposed within the inner cavity. The catheter of claim 9, wherein the diameter of the inner cavity of the tip distal to the distal end of the second tubular member is greater than or equal to the inner diameter of the second tubular member at the distal end of the second tubular member. The tip includes a first thin portion located distal to the protrusion and thinner than the protrusion;
The catheter according to claim 1 , further comprising a first thick-walled portion located distal to the first thin-walled portion and thicker than the first thin-walled portion. The catheter according to claim 1, wherein the outer member is cylindrical and has an inner cavity extending in the longitudinal direction, and at least a portion of the first cylindrical member and at least a portion of the second cylindrical member are disposed in the inner cavity. the outer member has a columnar body extending in the longitudinal direction and including a resin,
The catheter of claim 1 , wherein at least a portion of the first tubular member and at least a portion of the second tubular member are disposed within the cylinder. The catheter according to claim 1, wherein the first tubular member and the second tubular member are fixed to each other in the radial direction. The catheter according to claim 1, wherein a handle portion is disposed at the proximal end of the first tubular member.

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