JP2025023675A - catheter - Google Patents

Abstract

To provide a catheter that can be easily inserted into a meandering part in the body.SOLUTION: A catheter includes: a first cylindrical member; a second cylindrical member adjacent to the first cylindrical member in a radial direction; an outside cylindrical member having a stationary part including part of the first cylindrical member, which is fixed to the first cylindrical member, and a non-stationary part located more on a proximal side than the stationary part, which is not fixed to the first cylindrical member; a first linear member, at least part of which is disposed in the outside cylindrical member; and a second linear member, at least part of which is disposed in the outside cylindrical member. The first linear member is fixed to the non-stationary part of the outside cylindrical member or the first cylindrical member in at least a part more on a proximal side than the stationary part of the outside cylindrical member and more on a distal side than a middle point in a longitudinal direction of the non-stationary part. A distal end part of the second linear member is fixed at least to the stationary part of the outside cylindrical member.SELECTED DRAWING: Figure 1

Description

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 discloses such a catheter, which includes a first tubular member that extends in the longitudinal direction, has a distal end and a proximal end, and into which a wire is inserted, and a second tubular member that has a distal end and a proximal end and is adjacent to the first tubular member in the radial direction, the distal end of the first tubular member being located proximal to the distal end of the second tubular member, the proximal end of the first tubular member being located proximal to the proximal end of the second tubular member, the first tubular member having a reinforcing part having an inner layer containing at least one selected from the group consisting of polytetrafluoroethylene and tetrafluoroethylene-perfluoroalkylvinylether copolymer and a reinforcing member, and the first tubular member having a resin extension part that does not contain the polytetrafluoroethylene, the tetrafluoroethylene-perfluoroalkylvinylether copolymer, and the reinforcing member, distal to the distal end of the reinforcing part.

International Publication No. 2020/255737

Patent Document 1 describes an embodiment in which the outer surface of the first tubular member of the catheter has a metal reinforcing wire, and states that such an embodiment can improve the transmission of pushing force. The inventors' research has revealed that fixing multiple such linear members inside the catheter with their distal ends aligned in the longitudinal direction improves the transmission of pushing force, but makes it difficult for the catheter to bend and insert when inserting it into a curved part inside the body, such as a coronary artery. The present invention has been made in consideration of the above circumstances, and its purpose is to provide a catheter that is easy to insert into a curved part inside the body.

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 tubular member extending in the longitudinal direction, containing a portion of the first tubular member, and having a fixed portion fixed to the first tubular member, and a non-fixed portion located proximal to the fixed portion and not fixed to the first tubular member;
a first linear member extending in the longitudinal direction and at least a portion of which is disposed within the outer cylindrical member;
a second linear member extending in the longitudinal direction and at least a portion of which is disposed within the outer 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;
the first linear member is fixed to the non-fixed portion of the outer tubular member or the first tubular member in at least a portion that is proximal to the fixed portion of the outer tubular member and distal to a midpoint in the longitudinal direction of the non-fixed portion,
A catheter in which the distal end of the second linear member is fixed to at least the fixing portion of the outer tubular member.

The inventors' investigations have revealed that by fixing the first linear member to a portion proximal to the fixed portion of the outer tubular member, and further fixing the distal end of the second linear member to the fixed portion of the outer tubular member, it is possible to improve the transmission of pushing force between the portion proximal to the fixed portion of the outer tubular member and the portion distal to the fixed portion. Furthermore, it has been found that by positioning the distal end of the portion to which the first linear member is fixed proximal to the distal end of the portion to which the second linear member is fixed, the portion between these distal ends tends to curve appropriately when the catheter is pushed into a curved portion inside the body. These configurations make it easier to insert the catheter into curved portions inside the body.

Furthermore, the catheter according to the embodiment is preferably any one of the following [2] to [19].
[2] A catheter as described in [1], wherein the outer tubular member is located proximal to the proximal end of the second tubular member.
[3] A catheter described in [1] or [2], wherein the distal end of the second linear member is further fixed to the proximal end of the second tubular member.
[4] A catheter described in any of [1] to [3], wherein the first linear member is fixed to the non-fixed portion of the outer tubular member in at least a portion of the portion distal to the midpoint.
[5] A catheter described in any of [1] to [4], wherein the distal end of the first linear member is located proximal to the fixed portion of the outer tubular member and distal to the midpoint.
[6] A catheter described in any of [1] to [5], wherein the second linear member is not fixed to the first tubular member and the outer tubular member, at least in a portion that is proximal to the fixed portion of the outer tubular member and distal to the midpoint.
[7] In a cross section in the radial direction including a portion to which the first linear member is fixed,
The catheter according to any one of [1] to [6], wherein a center of the first linear member, a center of the outer tubular member, and a center of the second linear member are not located on the same straight line.
[8] A catheter described in any of [1] to [7], wherein the outer tubular member has a first portion which is on the side of the outer tubular member closer to the second tubular member in the radial direction and in which the first linear member and the second linear member are arranged.
[9] A catheter as described in [8], wherein the first portion is at least a part of a region of the outer tubular member that is proximal to the fixed portion and distal to the midpoint in the longitudinal direction of the non-fixed portion.
[10] A catheter described in any of [1] to [9], wherein, in the radial cross section of the portion where the first linear member is fixed, the second linear member is closer to the second tubular member than the first linear member.
[11] A catheter described in any of [1] to [10], wherein, in the radial cross section of the portion where the first linear member is fixed, the outer diameter of the first linear member is smaller than the outer diameter of the second linear member.
[12] A catheter described in any of [1] to [11], wherein the outer diameter of the non-fixed portion of the outer tubular member is larger than the outer diameter of the fixed portion of the outer tubular member.
[13] A catheter described in any of [1] to [12], wherein the first linear member is a solid member having no internal lumen, and the second linear member is a solid member having no internal lumen.
[14] Further, the catheter includes an outer member extending in the longitudinal direction and positioned distal to the outer tubular member,
The catheter according to any one of [1] to [13], wherein the outer member has a portion that contains a portion of the first tubular member and at least a portion of the second tubular member.
[15] A catheter as described in [14], wherein the outer member is tubular and has an inner lumen 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 lumen.
[16] The outer member has a columnar body extending in the longitudinal direction and containing a resin,
The catheter according to [14], 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.
[17] A catheter described in any one of [1] to [16], wherein the first tubular member and the second tubular member are fixed to each other in the radial direction.
[18] A catheter described in any one of [1] to [17], wherein a handle portion is disposed at the proximal end of the first tubular member.
[19] A proximal end portion of the first linear member is fixed to a proximal end portion of the first tubular member, a proximal end portion of the outer tubular member, or the handle portion;
The catheter described in [18], wherein the proximal end of the second linear member is fixed to the proximal end of the first tubular member, the proximal end of the outer tubular member, or the handle portion.

The present invention provides a catheter that is easy to insert into curved areas inside the body due to the above configuration.

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. FIG. 3 is a longitudinal cross-sectional view of region R2 in FIG. FIG. 4 is a cross-sectional view of the catheter of FIG. 1 taken along line AA. FIG. 5 is a cross-sectional view of a modified example of the catheter of FIG. 1 taken along the line AA. FIG. 6 is a cross-sectional view of the catheter of FIG. 1 taken along line BB. FIG. 7 is a cross-sectional view of the catheter of FIG. 1 taken along the line CC. FIG. 8 is a side view of a variation of the catheter of FIG. FIG. 9 is a side view of a variation of the catheter of FIG. FIG. 10 is a cross-sectional view taken along the line CC of a modification of the catheter of FIG.

The present invention will be described in more detail below based on the following embodiment, but the present invention is not limited to the following embodiment, and can of course be modified as appropriate within the scope of the above and below, all of which are included in the technical scope of the present invention. In addition, for convenience, component symbols may be omitted in each drawing, 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 helping understand the features of the present invention.

The catheter according to the embodiment includes 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 tubular member extending in the longitudinal direction, containing a portion of the first tubular member, and having a fixed portion fixed to the first tubular member and a non-fixed portion located proximal to the fixed portion and not fixed to the first tubular member, a first linear member extending in the longitudinal direction and at least a portion of which is disposed within the outer tubular member, and a second linear member extending in the longitudinal direction and at least a portion of which is disposed within the outer tubular member. and a second linear member that is fixed to the first tubular member, the distal end of the first tubular member being located proximal to the distal end of the second tubular member, the proximal end of the first tubular member being located proximal to the proximal end of the second tubular member, the first linear member being proximal to the fixed portion of the outer tubular member and fixed to the non-fixed portion of the outer tubular member or the first tubular member in at least a portion distal to the midpoint in the longitudinal direction of the non-fixed portion, and the distal end of the second linear member being fixed to at least the fixed portion of the outer tubular member.

The inventors' investigations have revealed that by fixing the first linear member to a portion proximal to the fixed portion of the outer tubular member, and further fixing the distal end of the second linear member to the fixed portion of the outer tubular member, it is possible to improve the transmission of pushing force between the portion proximal to the fixed portion of the outer tubular member and the portion distal to the fixed portion. Furthermore, it has been found that by positioning the distal end of the portion to which the first linear member is fixed proximal to the distal end of the portion to which the second linear member is fixed, the portion between these distal ends tends to curve appropriately when the catheter is pushed into a curved portion inside the body. These configurations make it easier to insert the catheter into curved portions inside the body.

Below, a catheter according to an embodiment will be described with reference to Figures 1 to 10. Figure 1 is a side view of a catheter according to an embodiment. Figure 2 is a longitudinal cross-sectional view of region R1 in Figure 1. Figure 3 is a longitudinal cross-sectional view of region R2 in Figure 1. Figure 4 is an A-A cross-sectional view of the catheter in Figure 1. Figure 5 is an A-A cross-sectional view of a modified example of the catheter in Figure 1. Figure 6 is a B-B cross-sectional view of the catheter in Figure 1. Figure 7 is a C-C cross-sectional view of the catheter in Figure 1. Figure 8 is a side view of a modified example of the catheter in Figure 1. Figure 9 is a side view of a modified example of the catheter in Figure 1. Figure 10 is a C-C cross-sectional view of a modified example of the catheter in Figure 1.

1, 2, and 3, the catheter according to the embodiment is a catheter 91 having 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. The first tubular member 1 preferably has a lumen 1L extending in the longitudinal direction X. The second tubular member 2 preferably has a 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, by inserting a search wire into the lumen 1L or the lumen 2L, it is easier to search for the entrance of a stenosis, which is a lesion. Of these, it is preferable to insert a search wire into the lumen 1L.

It is preferable that the first tubular member 1 and the second tubular member 2 each 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. It is preferable that the inner layer of the first tubular member 1 and the inner layer of the second tubular member 2 each 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 first lumen 1L and the second lumen 2L. The polyolefin resin is preferably polyethylene, polypropylene, an ethylene-propylene copolymer, or a mixture thereof. It is preferable that the polyethylene is 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. When the outer layers contain a flexible resin, the catheter 91 becomes easier to bend. 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 more 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.

It is preferable that the inner layer, intermediate layer, and outer layer are each fixed to the adjacent layer. This makes it difficult for each layer to twist or twist. Examples of the manner of fixing include welding and adhesion. Although not shown, a reinforcing member may be disposed as the intermediate layer.

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 thereof. 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 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 wire from breaking through the first tubular member 1.

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.

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.

1 and 3, the catheter 91 further has an outer tubular member 3 extending in the longitudinal direction X. The outer tubular member 3 contains a part of the first tubular member 1. Specifically, the outer tubular member 3 has an inner cavity 3L extending in the longitudinal direction X, and it is preferable that a part of the first tubular member 1 is disposed in the inner cavity 3L. The outer tubular member 3 can protect the first tubular member 1 while improving the transmission of the pushing force. The outer tubular member 3 and the first tubular member 1 can form a double tube structure (coaxial structure), which can reduce the risk of the catheter 91 breaking through when inserting a wire into the inner cavity 1L of the first tubular member 1.

1 and 3, the outer tubular member 3 has a fixed portion 3F fixed to the first tubular member 1 and a non-fixed portion 3G located proximal to the fixed portion 3F and not fixed to the first tubular member 1. The fixed portion 3F can prevent the outer tubular member 3 from coming off while improving the transmission of the pushing force. Examples of the fixing method include welding and adhesion. On the other hand, the non-fixed portion 3G is a portion of the outer tubular member 3 that is not fixed to the first tubular member 1 over the entire circumference in the circumferential direction, as shown in FIG. 4, for example. The non-fixed portion 3G makes it easier for the first tubular member 1 to move, making it easier to release the force associated with the insertion of a guide wire or the like into the first tubular member 1. Therefore, it is preferable that the non-fixed portion 3G is longer than the fixed portion 3F in the longitudinal direction X. This can reduce the risk of the wire breaking through the first tubular member 1. In the longitudinal direction X, the length of the non-fixed portion 3G is preferably 50 times or more and 200 times or less, and more preferably 100 times or more and 150 times or less, the length of the fixed portion 3F. The length of the fixed portion 3F in the longitudinal direction X is preferably 1 mm or more and 10 mm or less. In addition, the outer tubular member 3 preferably has another fixed portion that is fixed to the handle portion 8 at the proximal end.

The outer tubular member 3 is preferably located closer to the proximal end 2A of the second tubular member 2. Specifically, the distal end of the outer tubular member 3 is preferably located closer to the proximal end 2A of the second tubular member 2. This allows the outer diameter of the outer tubular member 3 to be reduced.

The outer cylindrical 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. This can improve flexibility.

1, 3, 4, and 5, the catheter 91 further includes a first linear member 11 extending in the longitudinal direction X and at least a portion of which is disposed within the outer tubular member 3. The first linear member 11 is fixed to the non-fixed portion 3G of the outer tubular member 3 or the first tubular member 1 at least a portion of the first linear member 11 that is proximal to the fixed portion 3F of the outer tubular member 3 and distal to the midpoint 3M in the longitudinal direction X of the non-fixed portion 3G. By disposing the portion 11F to which the first linear member 11 is fixed in this manner, the transmission of the pushing force in the portion proximal to the fixed portion 3F of the outer tubular member 3 can be improved. It is preferable that at least the distal portion of the first linear member 11 is disposed within the outer tubular member 3, and it is more preferable that the distal portion and the proximal portion are disposed within the outer tubular member 3. This improves the transmission of the pushing force from inside the outer tubular member 3. It is preferable that at least the distal end of the first linear member 11 is fixed to the non-fixed portion 3G of the outer cylindrical member 3 or to the first cylindrical member 1. This can improve the transmission of the pushing force by the first linear member 11.

As shown in FIG. 4, at least a portion of the first linear member 11 distal to the midpoint 3M is fixed to the non-fixed portion 3G of the outer tubular member 3, thereby improving the transmission of the pushing force through the outer tubular member 3. On the other hand, as shown in FIG. 5, at least a portion of the first linear member 11 distal to the midpoint 3M is fixed to the first tubular member 1, thereby improving the transmission of the pushing force through the first tubular member 1. The first linear member 11 may have a portion fixed to the non-fixed portion 3G of the outer tubular member 3 and a portion fixed to the first tubular member 1, or may have only one of the portions.

As shown in FIG. 1, it is preferable that the first linear member 11 is fixed to the non-fixed portion 3G of the outer tubular member 3 or the first tubular member 1 in a portion distal to the midpoint 3M. In FIG. 1, the reference symbol 11F indicates the portion to which the first linear member 11 is fixed. In this way, the first linear member 11 has a fixed portion and an unfixed portion distal to the midpoint 3M, which makes it easier to achieve both improved pushing force and improved bendability. On the other hand, the first linear member 11 may be fixed to the first tubular member 1 over the entire portion distal to the midpoint 3M.

The distal end 11B of the first linear member 11 is preferably located closer to the fixing portion 3F of the outer tubular member 3 and more distal to the midpoint 3M. This makes it easier for the portion between the distal end 11B of the first linear member 11 and the distal end 12B of the second linear member 12 in the longitudinal direction X to bend, and improves the transmission of the pushing force distal to the midpoint 3M.

1 and 3, the catheter 91 further includes a second linear member 12 extending in the longitudinal direction X and at least a portion of which is disposed within the outer tubular member 3. As shown in FIGS. 3 and 6, the distal end 12b of the second linear member 12 is fixed to at least the fixed portion 3F of the outer tubular member 3. By fixing the distal end 12b of the second linear member 12 in this manner, the transmission of the pushing force in the portion distal to the fixed portion 3F of the outer tubular member 3 can be improved. Note that the symbol 12F in FIG. 1 indicates the portion to which the second linear member 12 is fixed. Although not shown, the entire second linear member 12 may be disposed within the outer tubular member 3.

3 and 7, it is preferable that the distal end 12b of the second linear member 12 is further fixed to the proximal end 2a of the second tubular member 2. By fixing the distal end 12b of the second linear member 12 to at least the fixing portion 3F of the outer tubular member 3 and the proximal end 2a of the second tubular member 2 in this manner, the transmission of the pushing force from the second linear member 12 to the second tubular member 2 can be improved.

3 and 7, it is preferable that the distal end 12b of the second linear member 12 is further fixed to the proximal end 2a of the first tubular member 1 and the second tubular member 2. By positioning the distal end 12b of the second linear member 12 between the first tubular member 1 and the second tubular member 2 in this manner, the second linear member 12 is less likely to be exposed outside the catheter 91, and the transmission of the pushing force to the first tubular member 1 and the second tubular member 2 can be improved.

As shown in FIG. 1, it is preferable that the second linear member 12 is not fixed to the first tubular member 1 and the outer tubular member 3 at least in a portion located proximal to the fixing portion 3F of the outer tubular member 3 and distal to the midpoint 3M. This makes it easier for the catheter 91 to bend in a portion located proximal to the fixing portion 3F and distal to the midpoint 3M. The second linear member 12 does not have to be fixed to the first tubular member 1 and the outer tubular member 3 over the entire portion proximal to the fixing portion 3F of the outer tubular member 3.

As shown in Figures 4 and 5, in a cross section in the radial direction Y including the portion 11F to which the first linear member 11 is fixed (hereinafter sometimes referred to as "cross section Y"), it is preferable that the center 11N of the first linear member 11, the center 3N of the outer tubular member 3, and the center 12N of the second linear member 12 are not located on the same straight line. If the centers 11N, 12N, and 3N are located on the same imaginary line in cross section Y, the catheter 91 will be difficult to bend in the direction from one side of the imaginary line to the other side, and from the other side to the one side, but because they are not located on the same imaginary line, the catheter 91 will be easily bent in multiple directions.

As shown in Figures 1, 3, 4, and 5, the outer cylindrical member 3 preferably has a first portion 3P1 in which the first linear member 11 and the second linear member 12 are arranged on the side 3R2 of the outer cylindrical member 3 that is closer to the second cylindrical member 2 in the radial direction Y. By arranging at least a portion of each of the first linear member 11 and the second linear member 12 on the side 3R2 of the outer cylindrical member 3 that is closer to the second cylindrical member 2 in this manner, it is possible to easily transmit a pushing force from each linear member to the first cylindrical member 1 and the second cylindrical member 2.

As shown in FIG. 1, the first portion 3P1 is preferably at least a part of the region of the outer tubular member 3 that is proximal to the fixed portion 3F and distal to the midpoint 3M in the longitudinal direction X of the non-fixed portion 3G. The first portion 3P1 is located proximal to the fixed portion 3F, which makes it easier for the fixed portion 3F and its vicinity to bend. The first portion 3P1 is located distal to the midpoint 3M, which improves the transmission of the pushing force to the region distal to the midpoint 3M. In this case, as shown in FIG. 1, the outer tubular member 3 preferably has a second portion 3P2 on the side 3R1 of the outer tubular member 3 farther from the second tubular member 2 in the radial direction Y, in which the first linear member 11 and the second linear member 12 are arranged. The second portion 3P2 is preferably located proximal to the first portion 3P1. Because the outer tubular member 3 has such a first portion 3P1 and a second portion 3P2, when the catheter 91 is inserted into a tortuous part inside the body, the outer tubular member 3 is more likely to bend in the direction from the side 3R2 closer to the second tubular member 2 toward the side 3R1 farther from the second tubular member 2.

As shown in FIG. 1, the outer cylindrical member 3 may have a third portion 3P3 in which the first linear member 11 or the second linear member 12 is arranged on the side 3R2 of the outer cylindrical member 3 that is closer to the second cylindrical member 2 in the radial direction Y, and the second linear member 12 or the first linear member 11 is arranged on the side 3R1 that is farther from the second cylindrical member 2. The third portion 3P3 is located between the first portion 3P1 and the second portion 3P2 in the longitudinal direction X, and can function as a transition portion between the first portion 3P1 and the second portion 3P2.

As shown in FIG. 8, the third portion 3P3 may be adjacent to the proximal side of the first portion 3P1 in the longitudinal direction X and extend to the proximal end of the outer tubular member 3. This makes it easier for the operator to push in the handle portion 8 even if they change the way they hold it.

As shown in FIG. 9, the first portion 3P1 may extend from the proximal side of the midpoint 3M of the outer tubular member 3 to the distal side of the midpoint 3M. This further improves the transmission of the pushing force.

As shown in Figures 4 and 5, in a cross section in the radial direction Y (cross section Y) including the portion 11F to which the first linear member 11 is fixed, it is preferable that the second linear member 12 is closer to the second tubular member 2 than the first linear member 11. In Figures 4 and 5, the upper side is the side closer to the second tubular member 2. By positioning the second linear member 12 closer to the second tubular member 2 than the first linear member 11, the transmission of the pushing force from the second linear member 12 to the second tubular member 2 can be improved.

The outer diameter of the non-fixed portion 3G of the outer tubular member 3 is preferably larger than the outer diameter of the fixed portion 3F of the outer tubular member 3. This makes it less likely that the wire will break through the first tubular member 1 and the non-fixed portion 3G of the outer tubular member 3 when inserting the wire into the lumen 1L. The outer diameter of the non-fixed portion means the diameter of the circle when the cross-sectional shape of the non-fixed portion in the radial direction Y is a circle, and means the diameter of the circumscribing circle of the non-fixed portion when the cross-sectional shape is another shape. The outer diameter of the fixed portion means the diameter of the circle when the cross-sectional shape of the fixed portion in the radial direction Y is a circle, and means the diameter of the circumscribing circle of the fixed portion when the cross-sectional shape is another shape.

As shown in Figures 4 and 5, in the radial Y cross section (cross section Y) of the portion 11F to which the first linear member 11 is fixed, the outer diameter of the first linear member 11 is preferably smaller than the outer diameter of the second linear member 12. This makes it easier for the portion to which the first linear member 11 is fixed to bend, and improves the transmission of the pushing force from the second linear member 12 to the first tubular member 1 and the second tubular member 2. The outer diameter of the linear member means the diameter of the circle when the cross-sectional shape of the linear member in the radial Y is a circle, and means the diameter of the circumscribing circle of the linear member when the cross-sectional shape is another shape.

The first linear member 11 and the second linear member 12 each preferably have a cross-sectional shape in the radial direction Y that is a circle, an ellipse, a polygon, or a rounded polygon, and more preferably a circle. This reduces the anisotropy of bending strength. It is preferable that the first linear member 11 is a solid member that does not have an inner cavity, and the second linear member 12 is a solid member that does not have an inner cavity. This improves the transmission of the pushing force.

As shown in FIG. 1, it is preferable that the first linear member 11 and the second linear member 12 each have a straight portion. The first linear member 11 and the second linear member 12 may each further have a curved portion or a bent portion. It is preferable that the curved portion or the bent portion is located proximal to the straight portion. It is preferable that the first linear member 11 and the second linear member 12 each are solid members without an internal cavity. This can further improve the pushing force. The number of linear members in the catheter 91 is preferably two, but may be three or more, or five or less.

As shown in FIG. 3, the second linear member 12 preferably has a constant diameter portion 12U that extends in the longitudinal direction X and has a constant radial length. More preferably, the second linear member 12 further has a tapered portion 12T that is located distal to the constant diameter portion 12U and tapers toward the distal side. The constant diameter portion 12U improves the pushing force, and the tapered portion 12T makes it easier for the second linear member 12 to bend. The tapered portion 12T is preferably located at least within the fixed portion 3F of the outer tubular member 3.

Although not shown, the first linear member 11 preferably has a constant diameter section that extends in the longitudinal direction X and has a constant radial length. More preferably, the first linear member 11 further has a tapered section that is located distal to the constant diameter section and tapers toward the distal side. The constant diameter section improves the pushing force, and the tapered section makes it easier for the first linear member 11 to bend. The tapered section 12T of the second linear member 12 is preferably located distal to the tapered section of the first linear member 11. This makes it easier to bend smoothly from the distal side to the proximal side.

As shown in FIG. 1, the proximal end 11a of the first linear member 11 is preferably fixed to the proximal end 1a of the first tubular member 1, the proximal end 3a of the outer tubular member 3, or the handle portion 8. The proximal end 12a of the second linear member 12 is preferably fixed to the proximal end 1a of the first tubular member 1, the proximal end 3a of the outer tubular member 3, or the handle portion 8. This improves the transmission of the pushing force. Examples of the manner of fixing include welding and adhesion.

The proximal ends of the first linear member 11 and the second linear member 12 are preferably located within the handle portion 8. This makes it easier to transmit a pushing force from the handle portion 8 to the first linear member 11 and the second linear member 12.

The first linear member 11 and the second linear member 12 each preferably contain a metal, and more preferably are made of a metal. The metal is preferably stainless steel, nickel titanium, cobalt chrome, or an alloy of these. This can further improve the pressing force.

As shown in Figures 1, 2, and 3, the catheter 91 preferably further has an outer member 4 extending in the longitudinal direction X and located distal to the outer tubular member 3. The outer member 4 preferably has a portion that contains a portion of the first tubular member 1 and at least a portion of the second tubular member 2. The outer member 4 can protect the first tubular member 1 and the second tubular member 2, and can also make it easier to prevent the wire from breaking through from inside the catheter 91.

The outer member 4 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 outer tubular member 3 preferably contains the same resin as the outer member 4 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 3 and the proximal end of the outer member 4 are preferably fixed to each other.

As shown in FIG. 7, the outer member 4 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 first lumen 1L and the second lumen 2L extending in the longitudinal direction X even if the catheter 91 is curved. The columnar body 5 is preferably disposed at least between the proximal end 2A and the distal end 2B of the second tubular member 2. 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 91 into the body.

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

As shown in FIG. 2, the distal end 4B of the outer member 4 is preferably located distal to the distal end 2B of the second tubular member 2. By positioning the outer member 4 made of a flexible material in this manner, the flexibility of the portion of the catheter 91 distal to the distal end 2B of the second tubular member 2 can be improved.

It is preferable that at least a portion of the inner surface of the outer member 4 is fixed to the outer surface of the second tubular member 2. Furthermore, it is more preferable that at least a portion of the inner surface of the outer member 4 is fixed to the outer surface of the first tubular member 1. This makes it difficult for the outer member 4 to twist or kink. Examples of the manner of fixing include welding, adhesion, etc.

It is preferable that the length in the longitudinal direction X from the distal end 4B of the outer member 4 to the distal end 2B of the second tubular member 2 is greater than the maximum thickness of the second tubular member 2. This improves the flexibility of the catheter 91 near its distal end.

As shown in FIG. 10, the outer member 4 is cylindrical and has a lumen 4L extending in the longitudinal direction X, and at least a part of the first cylindrical member 1 and at least a part of the second cylindrical member 2 may be disposed in the lumen 4L. This makes it possible to protect the first cylindrical member 1 and the second cylindrical member 2, and also allows each cylindrical member to move to a certain extent due to the gap between the outer member 4 and the first cylindrical member 1 and the gap between the outer member 4 and the second cylindrical member 2, so that the force of the guide wire, etc. from the inside of the catheter 91 can be released, and as a result, it is possible to easily prevent the guide wire, etc. from being broken through. The distal end of the cylindrical outer member 4 is preferably fixed to the first cylindrical member 1 and the second cylindrical member 2. Furthermore, the proximal end of the cylindrical outer member 4 is preferably fixed to the first cylindrical member 1 and the second cylindrical member 2. This makes it difficult for the cylindrical outer member 4 to twist or twist.

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

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

As shown in FIG. 2, the outer member 4 is preferably located distal to the distal end 1B of the first tubular member 1 and has a protruding portion 41 protruding away from the central axis 2C on the side closer to the first tubular member 1 in the radial direction Y. 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 protruding portion 41 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 protruding portion 41.

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, the protuberance 41 preferably 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. The second inclined portion is preferably located distal to 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, although not shown, the outer member 4 may not have a protruding portion protruding in a direction 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. This reduces the outer diameter of the catheter 91 by the amount of the protruding portion, making it easier for the catheter 91 to bend.

As shown in Figures 7 and 10, it is preferable that the first tubular member 1 and the second tubular member 2 are fixed to each other 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 fixed to each other in the radial direction Y. This makes the first tubular member 1 and the second tubular member 2 less likely to twist or distort, improving the transmission of the pushing force. Furthermore, this makes it easier to hold the distal end portion 12b of the second linear member 12 between the first tubular member 1 and the second tubular member 2. Examples of the manner of fixing include welding, adhesion, etc.

As shown in FIG. 7, it is preferable that the first tubular member 1 and the second tubular member 2 are each fixed to the outer member 4. 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 each fixed to the inner surface of the outer member 4. This makes the first tubular member 1 and the second tubular member 2 less likely to twist or distort, improving the transmission of the pushing force.

Although not shown, the first tubular member 1 and the second tubular member 2 do not have to be fixed to each other in the radial direction Y. For example, as shown in FIG. 10, when the outer member 4 is cylindrical, if the first tubular member 1 and the second tubular member 2 are not fixed to each other in the radial direction Y, the force associated with inserting the wire into the first tubular member 1 or the second tubular member 2 can be easily released. Also, the first tubular member 1 and the second tubular member 2 do not have to be fixed to the outer member 4. This makes it easier to release the force associated with inserting the wire into the first tubular member 1 or the second tubular member 2.

The outer diameters of the first tubular member 1 and the second tubular member 2 are preferably 0.2 mm or more and 0.8 mm or less, and more preferably 0.3 mm or more and 0.7 mm or less. This makes it easier to insert the catheter 91 into the curved portion of the coronary artery.

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 gripping and pushing the handle portion 8. The outer shape of the handle portion 8 may be such that the practitioner can grip 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.

It is preferable that the proximal end 1A of the first tubular member 1 is located within the handle portion 8. This improves the pushing force.

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. A wire can be inserted through this inner cavity.

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 distal end 1B of the first tubular member 1 and proximal to the distal end 2B of the second tubular member 2. This makes it easier to grasp the position of the curved part of the catheter 91 when inserting the catheter 91 into a curved part inside the body, making insertion easier.

The radiopaque marker is preferably ring-shaped. The radiopaque marker preferably contains a radiopaque material, and more preferably consists 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, and tantalum.

Although not shown, the catheter 91 may further have a tip extending in the longitudinal direction X. It is preferable that the tip has an inner cavity extending in the longitudinal direction X, and that at least the distal end of the second tubular member 2 is disposed within the inner cavity. This makes it easier for the tip and the second tubular member 2 to bend integrally.

It is preferable that at least a portion of the inner surface of the tip is fixed to the outer surface of the second cylindrical member 2. This makes it easier for the tip and the second cylindrical member 2 to bend integrally. Examples of the manner of fixing include welding, adhesion, etc.

The chip preferably contains a flexible resin. 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 having a specific gravity of 0.91 to 0.92.

The catheter 91 can be preferably used to treat narrowing or dilating occlusions in passages such as blood vessels in the body, and can be preferably used in performing coronary intervention (PCI) for lesions at the bifurcation of the coronary artery.

1 First tubular member 1a Proximal end 1A Proximal end 1B Distal end 1C Central axis 1E First opening 1L Lumen 2 Second tubular member 2a Proximal end 2A Proximal end 2B Distal end 2C Central axis 2E Second opening 2L Lumen 3 Outer tubular member 3a Proximal end 3F Fixed portion 3G Non-fixed portion 3L Lumen 3M Midpoint 3N Center 3P1 First portion 3P2 Second portion 3P3 Third portion 3R1 Side farther from second tubular member 3R2 Side closer to second tubular member 4 Outer member 4L Lumen 5 Cylinder 6A, 6B X-ray impermeable marker 8 Handle portion 11 First linear member 11a Proximal end 11B Distal end 11F Fixed portion 11N Center 12 Second linear member 12a Proximal end 12b Distal end 12F Fixed portion 12N Center 12T Tapered portion 12U Constant diameter portion 41 Protuberance 91 Catheter X Longitudinal direction Y Radial direction

Claims (19)

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 tubular member extending in the longitudinal direction, containing a portion of the first tubular member, and having a fixed portion fixed to the first tubular member, and a non-fixed portion located proximal to the fixed portion and not fixed to the first tubular member;
a first linear member extending in the longitudinal direction and at least a portion of which is disposed within the outer cylindrical member;
a second linear member extending in the longitudinal direction and at least a portion of which is disposed within the outer 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;
the first linear member is fixed to the non-fixed portion of the outer tubular member or the first tubular member in at least a portion that is proximal to the fixed portion of the outer tubular member and distal to a midpoint in the longitudinal direction of the non-fixed portion,
A catheter in which the distal end of the second linear member is fixed to at least the fixing portion of the outer tubular member. The catheter according to claim 1, wherein the outer tubular member is located proximal to the proximal end of the second tubular member. The catheter according to claim 1 or 2, wherein the distal end of the second linear member is further fixed to the proximal end of the second tubular member. The catheter according to claim 1 or 2, wherein the first linear member is fixed to the non-fixed portion of the outer tubular member in at least a portion of the portion distal to the midpoint. The catheter according to claim 1 or 2, wherein the distal end of the first linear member is located proximal to the fixed portion of the outer tubular member and distal to the midpoint. The catheter according to claim 1 or 2, wherein the second linear member is not fixed to the first tubular member and the outer tubular member at least in a portion located proximal to the fixing portion of the outer tubular member and distal to the midpoint. In the radial cross section including the portion to which the first linear member is fixed,
The catheter according to claim 1 or 2, wherein a center of the first linear member, a center of the outer tubular member, and a center of the second linear member are not positioned on the same line. The catheter according to claim 1 or 2, wherein the outer cylindrical member has a first portion that is closer to the second cylindrical member in the radial direction and in which the first linear member and the second linear member are disposed. The catheter according to claim 8, wherein the first portion is at least a portion of a region of the outer tubular member that is proximal to the fixed portion and distal to the midpoint in the longitudinal direction of the non-fixed portion. The catheter according to claim 1 or 2, wherein in the radial cross section of the portion to which the first linear member is fixed, the second linear member is closer to the second tubular member than the first linear member. The catheter according to claim 10, wherein the outer diameter of the first linear member is smaller than the outer diameter of the second linear member in the radial cross section of the portion where the first linear member is fixed. The catheter according to claim 1 or 2, wherein the outer diameter of the non-fixed portion of the outer tubular member is larger than the outer diameter of the fixed portion of the outer tubular member. The catheter according to claim 1 or 2, wherein the first linear member is a solid member having no lumen, and the second linear member is a solid member having no lumen. The catheter further includes an outer member extending in the longitudinal direction and positioned distal to the outer tubular member,
The catheter according to claim 1 or 2, wherein the outer member has a portion that contains a portion of the first tubular member and at least a portion of the second tubular member. The catheter according to claim 14, wherein the outer member is tubular and has an inner lumen 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 lumen. the outer member has a columnar body extending in the longitudinal direction and including a resin,
The catheter of claim 14 , 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 or 2, 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 or 2, wherein a handle portion is disposed at the proximal end of the first tubular member. a proximal end portion of the first linear member is fixed to a proximal end portion of the first tubular member, a proximal end portion of the outer tubular member, or the handle portion;
The catheter according to claim 18, wherein the proximal end of the second linear member is fixed to the proximal end of the first tubular member, the proximal end of the outer tubular member, or the handle portion.

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