catheter

Abstract

To provide a catheter which is capable of easily preventing a wall of the body cavity from being damaged while transported to a treatment part, and of easily improving passability in the body cavity.SOLUTION: A catheter 1 has: a first member 10 which has a distal end 10d and a proximal end 10p and is provided with a lumen extending in a longitudinal direction x; a bag-shaped body 30 which is provided at a distal part of the first member, is formed into an annular shape, has an outer surface, an inner surface, and an interior space, and has an inner diameter smaller than that of the first member; and a second member 20 disposed in the bag-shaped interior space. The first member is movable in the longitudinal direction x relative to the second member, at least a part of a surface on the interior space side of the bag-shaped body contacts the surface of the second member in the state that the second member is disposed inside the bag-shaped body, and a minimum internal diameter of the bag-shaped body in the state that the inner surface of the bag-shaped body contacts the outer surface of the second member is larger than a minimum inner diameter of the bag-shaped body in the state that the second member is positioned on a close proximity side of the bag-shaped body.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a catheter.

Background Art

[0002] When transporting medical devices such as balloons and stents to a treatment site that is the target of treatment, for example, a resin tube is used. Specifically, the medical device is inserted into a body cavity such as a blood vessel in a state where it is arranged in the lumen of the resin tube and is transported to the treatment site. When the resin tube used at this time has a simple cylindrical shape, there are problems such as damage to the wall of the body cavity and poor permeability due to the tip portion hitting the wall of the body cavity.

[0003] Patent Document 1 describes a catheter that can be less likely to damage the wall of a body cavity. The catheter has a long elastic tube-like component having at least one lumen. A soft and deformable tip component is attached to the distal end of the catheter, and the outer diameter of the tip component expands and the contact area increases by pressing it against a relatively stationary surface. It is described that this can reduce the pressure or force per unit area applied to the tissue.

[0004] Patent Document 2 describes an instrument for medical technology with good operability. The instrument has a vertically long tubular variable internal body, a vertically long outer coating body that at least fragmentarily surrounds the internal body on the circumferential side, and a device for shifting the instrument from a variable state to a rigid state and vice versa. The internal body is formed in the form of a double tube having an inner tube that constitutes the inner wall and an outer tube that constitutes the outer wall and concentrically surrounds the inner tube. The device for shifting the instrument from a variable state to a rigid state and vice versa increases the pressure in the annular gap to expand the outer tube in the radial direction to apply pressure to the coating body to make the instrument rigid, and it is described that the operation is easy. Also, it is described that the outer diameter of the double tube of the internal body increases, but the internal space of the internal body remains fixed in size. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 60-040069 [Patent Document 2] Special Publication No. 2009-505700 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, the catheter described in Patent Document 1 prevents damage to the body cavity by expanding the outer diameter of the tip component. With the configuration of the catheter described in Patent Document 1, the expanded tip portion is prone to getting caught on the wall of the body cavity, and the problem of poor passage through the body cavity could not be solved.

[0007] The medical device described in Patent Document 2 also improves operability by creating a rigid state through the application of pressure to expand its outer diameter. However, the expanded portion tends to catch on the walls of the body cavity, and there is still room for improvement in terms of improving passage through the body cavity.

[0008] Furthermore, in both the catheter described in Patent Document 1 and the medical device described in Patent Document 2, it was necessary to ensure an inner diameter large enough for the medical device to pass through, in order to transport the medical device, such as a balloon or stent, to the treatment area and then place the medical device on the treatment area.

[0009] The present invention has been made in view of the above circumstances, and its object is to provide a catheter that can easily prevent damage to the wall of the body cavity when transported to the treatment site, and can also easily improve passability within the body cavity. [Means for solving the problem]

[0010] One embodiment of the catheter of the present invention that solves the above problems comprises a first member having a distal end and a proximal end and a lumen extending in the longitudinal direction, a bag-like body provided at the distal end of the first member, formed in an annular shape, having an outer surface, an inner surface and an internal space, and having an inner diameter smaller than the inner diameter of the first member, and a second member disposed in the internal space of the bag-like body, wherein the first member is movable in the longitudinal direction relative to the second member, and when the second member is disposed inside the bag-like body, at least a portion of the surface on the internal space side of the bag-like body is in contact with the surface of the second member, and the minimum inner diameter of the bag-like body when the inner surface of the bag-like body and the outer surface of the second member are in contact is larger than the minimum inner diameter of the bag-like body when the second member is located proximal to the proximal end of the bag-like body. First, the catheter with the second member located proximal to the proximal end of the bag-like body is transported to the treatment area. Because the second component is positioned proximal to the proximal end of the bag-like structure, the inner diameter of the bag-like structure becomes smaller. This smaller inner diameter makes it less likely for the catheter to come into contact with the body cavity wall during transport to the treatment site, thus reducing the risk of damaging the wall and preventing the catheter from getting caught on the wall. Furthermore, after the catheter reaches the treatment site, by ensuring that the outer surface of the second component is in contact with the inner surface of the bag-like structure, the minimum inner diameter of the bag-like structure becomes larger than the minimum inner diameter of the bag-like structure when the second component is positioned proximal to the proximal end of the bag-like structure. As a result, when medical devices such as balloons, stents, baskets, or needles are placed in the lumen of the first component and transported to the treatment site, it becomes easier to protrude the medical devices from the bag-like structure.

[0011] In the catheter of the present invention, it is preferable that the diameter of the largest circle tangent to the surface of the second member in a cross section perpendicular to the longitudinal direction centered on the central axis in the extending direction of the first member is larger than the minimum inner diameter of the bag-like body in its natural state when no external force is applied to the bag-like body.

[0012] In the catheter of the present invention, it is preferable that the first member has a wall forming a lumen, and that an insertion passage is formed within the wall of the first member through which the second member is inserted.

[0013] In the catheter of the present invention, the first member preferably comprises an outer cylinder and an inner cylinder disposed within the lumen of the outer cylinder, and the insertion passage is a space partitioned by the inner surface of the outer cylinder and the outer surface of the inner cylinder.

[0014] In the catheter of the present invention, it is preferable that the internal space is in communication with the insertion passage.

[0015] In the catheter of the present invention, it is preferable that the internal space does not communicate with the lumen of the first member.

[0016] In the catheter of the present invention, it is preferable that at least one of the regions of the first member from the proximal end to 10 cm proximal and the second member from the distal end to 10 cm proximal has a radiopaque portion.

[0017] In the catheter of the present invention, it is preferable that the number of radiopaque portions located in the region from the distal end of the second member to 10 cm proximal is greater than the number of radiopaque portions located in the region from the proximal end of the sac-like body of the first member to 10 cm proximal.

[0018] In the catheter of the present invention, at least a bag-like body is provided with a first shape memory member, the elasticity of the first shape memory member is higher than that of the bag-like body, and in a natural state where no external force is applied to the first shape memory member, the diameter of the smallest circle that contacts the surface of the first shape memory member in a cross section perpendicular to the longitudinal direction centered on the central axis in the extending direction of the first member is preferably smaller than the inner diameter of the first member.

[0019] In the catheter of the present invention, the second member has a second shape memory portion at least at its distal portion, and the diameter of the largest circle that contacts the surface of the second shape memory portion in a cross-section perpendicular to the longitudinal direction about the central axis in the extending direction of the first member in the natural state where no external force is applied to the second shape memory portion is preferably larger than the diameter of the largest circle that contacts the surface of the second member in a cross-section perpendicular to the longitudinal direction about the central axis in the extending direction of the first member.

[0020] In the catheter of the present invention, it is preferable that the second member has a lumen extending in the longitudinal direction.

[0021] The catheter of the present invention has a first linear member, and the first linear member is preferably fixed to the proximal portion of the first member.

[0022] The catheter of the present invention further has a tubular member whose maximum outer diameter is smaller than the maximum outer diameter of the first member. The distal portion of the tubular member is fixed to the proximal portion of the second member, and the first linear member is preferably disposed in the lumen of the tubular member.

[0023] The catheter of the present invention has a second linear member, and the second linear member is preferably fixed to the proximal portion of the second member.

[0024] The catheter of the present invention further has a tubular member whose maximum outer diameter is smaller than the maximum outer diameter of the first member. The distal portion of the tubular member is fixed to the proximal portion of the first member, and the second linear member is preferably disposed in the lumen of the tubular member.

[0025] In the catheter of the present invention, it is preferable that the second member has a second diameter-reducing region at the proximal portion of the second member, where the radial length when observed from a direction perpendicular to the longitudinal direction becomes shorter toward the proximal side.

[0026] In the catheter of the present invention, it is preferable that the first member has a first diameter-reducing region at the proximal portion of the first member, the radial length of which, when observed from a direction perpendicular to the longitudinal direction, becomes shorter toward the proximal side.

[0027] In the catheter of the present invention, it is preferable that the lumen of the first member includes a shaft disposed movably with respect to the first member, and an expansion member provided at the distal portion of the shaft and expanding in the radial direction.

[0028] In the catheter of the present invention, it is preferable that the catheter further includes a control mechanism for suppressing the longitudinal movement of the shaft in the lumen of the first member.

[0029] In the catheter of the present invention, it is preferable that the expansion member is a balloon or a stent having a coating layer formed on the outer surface.

[0030] In the catheter of the present invention, it is preferable that the coating layer contains a physiologically active agent.

Advantages of the Invention

[0031] The catheter of the present invention can easily project a medical instrument even when transporting a medical instrument such as a balloon, a stent, a basket, a needle, etc. to the treatment site, can easily prevent damage to the wall of the body cavity when transporting it to the treatment site, and can easily improve the permeability in the body cavity.

Brief Description of the Drawings

[0032] [Figure 1] A side view showing an example of a catheter according to an embodiment of the present invention is represented. [Figure 2] A cross-sectional view parallel to the longitudinal direction of the catheter shown in FIG. 1, representing a state where the second member is located on the proximal side of the proximal end of the bag-shaped body. [Figure 3] A side view of the second member in the catheter shown in FIG. 1 is represented. [Figure 4]This shows a cross-sectional view of the second member at line IV-IV, as shown in Figure 3. [Figure 5] This shows a side view of a modified example of the second member shown in Figure 3. [Figure 6] Figure 5 shows a cross-sectional view of the second member from VI to VI. [Figure 7] Figure 1 is a cross-sectional view of the catheter parallel to its longitudinal direction, showing the state in which the second member is positioned inside the bag-like body. [Figure 8] Figure 7 shows a cross-sectional view of the catheter between points VIII and VIII. [Figure 9] This shows a cross-sectional view parallel to the longitudinal direction of a catheter according to another embodiment of the present invention. [Figure 10] This shows a cross-sectional view parallel to the longitudinal direction of a catheter according to yet another embodiment of the present invention. [Modes for carrying out the invention]

[0033] The present invention will be described in more detail below based on the embodiments described below. However, the present invention is not limited by the embodiments described below, and it is certainly possible to implement it with appropriate modifications within the scope that is consistent with the spirit of the preceding and following descriptions, and all such modifications are included within the technical scope of the present invention. In addition, hatching and component reference numerals may be omitted in the drawings for convenience, in which case please refer to the specification or other drawings. Furthermore, the dimensions of various components in the drawings may differ from the actual dimensions, as priority has been given to helping to understand the features of the present invention.

[0034] One embodiment of the catheter of the present invention comprises a first member having a distal end and a proximal end and a lumen extending in the longitudinal direction; a bag-like body provided at the distal end of the first member, formed in an annular shape, having an outer surface, an inner surface and an internal space, and having an inner diameter smaller than the inner diameter of the first member; and a second member disposed in the internal space of the bag-like body. The first member is movable in the longitudinal direction relative to the second member, and when the second member is disposed inside the bag-like body, at least a portion of the surface of the bag-like body on the internal space side is in contact with the surface of the second member. The minimum inner diameter of the bag-like body when the inner surface of the bag-like body and the outer surface of the second member are in contact is greater than the minimum inner diameter of the bag-like body when the second member is located proximal to the proximal end of the bag-like body.

[0035] The overall configuration of a catheter according to an embodiment of the present invention will be described with reference to Figures 1 to 10. Figures 1, 2, and 8 to 10 show a catheter 1 having a first member 10 and a second member 20. In these drawings, the longitudinal direction of the first member 10 is indicated by x and the radial direction by y. The radial direction y is perpendicular to the longitudinal direction x, but here only the one direction perpendicular to the longitudinal direction x is shown.

[0036] In this specification, the proximal side refers to the side of the first member 10 that is closer to the user's hand in the direction of extension, and the distal side refers to the opposite side of the proximal side, i.e., the side being treated. Furthermore, the distal portion of each member refers to the distal half of each member, and the proximal portion of each member refers to the proximal half of each member.

[0037] Figure 1 is a side view showing an example of a catheter 1 according to an embodiment of the present invention, and Figure 2 is a cross-sectional view of the catheter 1 parallel to the longitudinal direction x, showing a state in which the second member 20 is located proximal to the proximal end 30p of the bag-like body 30.

[0038] As shown in Figures 1 and 2, the catheter 1 comprises a first member 10, a sac-like body 30, and a second member 20. The first member 10 has a distal end 10d and a proximal end 10p, and has a lumen extending in the longitudinal direction x.

[0039] It is preferable that the first member 10 is flexible. The flexibility of the first member 10 allows it to deform to conform to the shape of the body cavity when inserted into the body. Furthermore, it is preferable that the first member 10 is elastic. The elasticity of the first member 10 allows it to maintain its shape even when deformed to conform to the shape of the body cavity, making it less likely for the lumen of the first member 10 to collapse.

[0040] Examples of the first member 10 include a hollow body formed by arranging one or more wires in a predetermined pattern, a hollow body with at least one of its inner or outer surfaces coated with resin, a resin tube, and a connection of these in the longitudinal direction x. Examples of a hollow body in which wires are arranged in a predetermined pattern include a cylindrical body having a mesh structure formed by simply crossing or weaving wires, or by cutting out a tube made of a metal tube or polymer material with a laser, and a coil in which wires are wound. The wires may be one or more single wires or one or more stranded wires. The resin tube can be manufactured, for example, by extrusion molding. Among these, the first member 10 is preferably a resin tube. By making the first member 10 a resin tube, it becomes easier to make the first member 10 which has excellent flexibility and elasticity.

[0041] If the first member 10 is a resin tube, the first member 10 can be composed of a single layer or multiple layers. The first member 10 may be composed of a single layer in part in the longitudinal direction x or in the circumferential direction, and the other part may be composed of multiple layers.

[0042] As materials for the first member 10, for example, synthetic resins such as polyolefin resins like polyethylene and polypropylene, polyamide resins like nylon, polyester resins like PET, aromatic polyether ketone resins like PEEK, polyether polyamide resins, polyurethane resins, polyimide resins, fluororesins like PTFE, PFA, and ETFE, and metals such as stainless steel, carbon steel, and nickel-titanium alloys can be used. These may be used individually or in combination of two or more.

[0043] It is preferable that the outer surface of the first member 10 is coated with a hydrophilic polymer. By coating the outer surface of the first member 10 with a hydrophilic polymer, the slipperiness of the outer surface of the first member 10 is improved, resulting in a catheter 1 that is easy to insert.

[0044] Examples of hydrophilic polymers include poly-2-hydroxyethyl methacrylate, polyacrylamide, polyvinylpyrrolidone, and maleic anhydride copolymers such as methyl vinyl ether maleic anhydride copolymers.

[0045] It is preferable that the inner surface of the first member 10 has a layer containing at least one of a fluororesin and a polyolefin resin. Only a part of the inner surface of the first member 10 may be made of fluororesin or polyolefin resin, or the entire inner surface of the first member 10 may be made of fluororesin or polyolefin resin. By having a layer containing at least one of a fluororesin and a polyolefin resin on the inner surface of the first member 10, the sliding properties of the inner surface of the first member 10 are improved, making it easier to move and release members placed in the lumen of the first member 10.

[0046] To provide the first member 10 with a layer on its inner surface containing at least one of a fluororesin and a polyolefin resin, examples include providing the first member 10 with a multilayer structure and using at least one of a fluororesin and a polyolefin resin as the material constituting the innermost layer, or applying a coating to the inner surface of the first member 10 containing at least one of a fluororesin and a polyolefin resin.

[0047] The length of the longitudinal direction x of the first member 10 can be selected to be an appropriate length depending on the length of the longitudinal direction x of the second member 20 which is positioned outside the lumen of the first member 10, or the length of the longitudinal direction x of the article which is positioned inside the lumen of the first member 10. For example, the length of the longitudinal direction x of the first member 10 can be 30 mm or more and 700 mm or less.

[0048] The outer diameter of the first member 10 can be appropriately selected as needed. For example, the outer diameter of the first member 10 can be 1 mm or more and 5 mm or less, and preferably 2 mm or less. By setting the outer diameter of the first member 10 within the above range, the outer diameter of the first member 10 can be kept small.

[0049] As shown in Figures 2 and 8, the bag-like body 30 is provided on the distal part of the first member 10, is formed in an annular shape, and has an outer surface 30A, an inner surface 30B, and an internal space 30C. The inner diameter of the bag-like body 30 is smaller than the inner diameter of the first member 10. The bag-like body 30 is an annular bag-shaped member and has a portion whose outer diameter is smaller than that of the first member 10. It is preferable that the shape of the bag-like body 30 is annular when viewed from the longitudinal direction x.

[0050] The material used to constitute the bag-like body 30 can be the same synthetic resin, metal, or the like used for the first member 10.

[0051] As shown in Figure 2, the proximal portion of the bag-like body 30 may be connected to the distal portion of the first member 10, or the proximal end 30p of the bag-like body 30 may be connected to the distal end 10d of the first member 10.

[0052] In a natural state where no external force is applied to the bag-like body 30, it is preferable that the shortest distance from the outer surface 30A to the inner surface 30B of the bag-like body 30 is smaller than the shortest distance from the outer surface to the inner surface of the first member 10. By making the shortest distance from the outer surface 30A to the inner surface 30B of the bag-like body 30 smaller than the shortest distance from the outer surface to the inner surface of the first member 10, the outer diameter of the distal end of the catheter 1 can be reduced, thereby improving the ease of insertion of the catheter 1.

[0053] In the bag-like body 30, the portion where the shortest distance from the outer surface 30A to the inner surface 30B is smaller than the shortest distance from the outer surface to the inner surface of the first member 10 is preferably located at the distal end of the bag-like body 30, more preferably at the distal end 30d of the bag-like body 30. This configuration of the bag-like body 30 makes it easier to maintain a small outer diameter, especially on the distal side, thus reducing the likelihood of snagging on the body cavity wall and preventing the catheter 1 from damaging the body cavity wall during transport to the treatment area. Furthermore, it also improves the passability of the catheter 1 within the body cavity.

[0054] The bag-like body 30 is formed in an annular shape, but for example, the bag-like body 30 may have a hollow frustoconical shape. The bag-like body 30 is formed in an annular shape and may have an internal space 30C that communicates with the outside of the bag-like body 30.

[0055] As shown in Figures 2 and 8, the internal space 30C is a space formed within the wall of the annular bag-like body 30. More specifically, the internal space 30C is a space formed within the wall that forms the lumen of the bag-like body 30. It is preferable that the internal space 30C exists throughout the entire circumferential direction within the wall of the bag-like body 30. Although not shown, the internal space 30C may exist only in a part of the circumferential direction within the wall of the bag-like body 30.

[0056] Preferably, the shortest distance from the outer surface 30A to the inner surface 30B at the distal end 30d of the bag-shaped body 30 is smaller than the shortest distance from the outer surface 30A to the inner surface 30B at the proximal end 30p of the bag-shaped body 30. By making the shortest distance from the outer surface 30A to the inner surface 30B at the distal end 30d of the bag-shaped body 30 smaller than the shortest distance from the outer surface 30A to the inner surface 30B at the proximal end 30p of the bag-shaped body 30, the rigidity of the distal side of the bag-shaped body 30 becomes lower than the rigidity of the proximal side of the bag-shaped body 30, making it easier to change the minimum inner diameter of the bag-shaped body 30 by contact between the second member 20 and the bag-shaped body 30.

[0057] The thickness of the proximal end 30p of the bag-like body 30 can be selected appropriately according to the thickness of the distal end 11d of the main body 11, etc. The thickness of the proximal end 30p of the bag-like body 30 can be about the same as the thickness of the distal end 11d of the main body 11, for example, it can be 0.01 mm or more and 0.5 mm or less.

[0058] The bag-like body 30 is preferably tapered, narrowing from the proximal to the distal end. The tapered shape of the bag-like body 30 allows for a smaller outer diameter at the distal end of the catheter 1, thereby improving the ease of insertion of the catheter 1.

[0059] As shown in Figures 1 and 2, and Figures 7 and 8, the second member 20 is positioned in the internal space 30C of the bag-like body 30, and the first member 10 is movable in the longitudinal direction x relative to the second member 20.

[0060] Figure 3 is a side view of the second member 20, and Figure 4 is a cross-sectional view of the second member 20 shown in Figure 3, perpendicular to the longitudinal direction x. Furthermore, Figure 5 is a modified example of the second member 20 shown in Figure 3, and is a side view of the second member 20, and Figure 6 is a cross-sectional view of the second member 20 shown in Figure 5, perpendicular to the longitudinal direction x.

[0061] Examples of the second member 20 include a cylindrical body as shown in Figures 3 and 4, a body formed from wires as shown in Figures 5 and 6, a hollow body formed by arranging one or more wires in a predetermined pattern, a hollow body with resin coated on at least one of its inner or outer surfaces, and a combination of these connected in the longitudinal direction x. As shown in Figures 5 and 6, when the second member 20 is composed of wires, the number of wires may be one or more. Examples of hollow bodies in which wires are arranged in a predetermined pattern include a cylindrical body having a mesh structure formed by simply crossing or weaving wires, or by cutting out a tube made of a metal tube or polymer material with a laser, and a coil in which wires are wound. The wires may be one or more single wires, or one or more stranded wires.

[0062] As materials for the second member 20, for example, metals such as stainless steel, carbon steel, and nickel-titanium alloys; polyolefin resins such as polyethylene and polypropylene; polyamide resins such as nylon; polyester resins such as PET; aromatic polyether ketone resins such as PEEK; polyether polyamide resins; polyurethane resins; polyimide resins; and synthetic resins such as PTFE, PFA, and ETFE. These may be used individually or in combination of two or more.

[0063] The length of the longitudinal direction x of the second member 20 can be selected to be an appropriate length depending on the length of the longitudinal direction x of the first member 10, etc. For example, the length of the longitudinal direction x of the second member 20 can be 15 mm or more and 600 mm or less.

[0064] The outer diameter of the second member 20 can be appropriately selected depending on the outer diameter of the first member 10 that comes into contact with the second member 20, the outer diameter of the bag-like body 30, etc. For example, the outer diameter of the second member 20 can be 0.5 mm or more and 4.8 mm or less. The inner diameter of the second member 20 can also be appropriately selected.

[0065] The thickness of the second member 20 can be selected to be an appropriate thickness, for example, 0.01 mm or more and 0.4 mm or less. The average thickness of the second member 20 can be, for example, 0.075 mm.

[0066] Figure 7 is a cross-sectional view of the catheter 1 parallel to the longitudinal direction x, showing the state in which the second member 20 is positioned inside the bag-like body 30, and Figure 8 is a cross-sectional view of the catheter 1 perpendicular to the longitudinal direction x. As shown in Figures 7 and 8, in the state in which the second member 20 is positioned inside the bag-like body 30, at least a portion of the surface of the bag-like body 30 on the side of the internal space 30C is in contact with the surface of the second member 20.

[0067] As shown in Figures 2, 7, and 8, the minimum inner diameter of the bag-shaped body 30 when the inner surface of the bag-shaped body 30 is in contact with the outer surface of the second member 20 is larger than the minimum inner diameter of the bag-shaped body 30 when the second member 20 is located proximal to the proximal end 30p of the bag-shaped body 30.

[0068] The minimum inner diameter of the bag-shaped body 30 when the inner surface of the bag-shaped body 30 is in contact with the outer surface of the second member 20 is greater than the minimum inner diameter of the bag-shaped body 30 when the second member 20 is located proximal to the proximal end 30p of the bag-shaped body 30. Therefore, by moving the second member 20 distal to the proximal end 30p of the bag-shaped body 30, the inner diameter of the bag-shaped body 30 can be increased.

[0069] First, the catheter 1 is transported to the treatment area with the second member 20 positioned proximal to the proximal end 30p of the bag-like body 30. Because the second member 20 is positioned proximal to the proximal end 30p of the bag-like body 30, the inner diameter of the bag-like body 30 becomes small. Because the inner diameter of the bag-like body 30 is small, when the catheter 1 is transported to the treatment area, the catheter 1 is less likely to come into contact with the wall of the body cavity, making it less likely to damage the wall of the body cavity, and the catheter 1 is less likely to get caught on the wall of the body cavity. Furthermore, after the catheter 1 reaches the treatment area, by making the outer surface of the second member 20 come into contact with the inner surface of the bag-like body 30, the minimum inner diameter of the bag-like body 30 becomes larger than the minimum inner diameter of the bag-like body 30 when the second member 20 is positioned proximal to the proximal end 30p of the bag-like body 30. As a result, when medical devices such as balloons, stents, baskets, and needles are placed in the lumen of the first member 10 and transported to the treatment area, it becomes easier to protrude the medical devices from the bag-like body 30.

[0070] The smallest inner diameter of the pouch-like body 30 is preferably located at the distal end 30d of the pouch-like body 30. In other words, the part with the smallest inner diameter of the pouch-like body 30 is preferably at the distal end 30d of the pouch-like body 30. By having the part with the smallest inner diameter of the pouch-like body 30 be at the distal end 30d of the pouch-like body 30, the outer diameter of the distal end of the catheter 1 becomes smaller, which improves the ease of insertion of the catheter 1.

[0071] Although not shown in the figures, it is preferable to have a lubricating coating layer between the first member 10 and the second member 20. Having a lubricating coating layer between the first member 10 and the second member 20 allows for smooth movement of the second member 20 in the longitudinal direction x relative to the first member 10. Examples of materials constituting the lubricating coating layer include silicone, fluororesin, and polyolefin resin, with silicone being particularly suitable.

[0072] The minimum inner diameter of the bag-shaped body 30 when the inner surface of the bag-shaped body 30 is in contact with the outer surface of the second member 20 is preferably 1.1 times or more, more preferably 1.3 times or more, and even more preferably 1.5 times or more, the minimum inner diameter of the bag-shaped body 30 when the second member 20 is located proximal to the proximal end 30p of the bag-shaped body 30. By setting the lower limit of the ratio of the minimum inner diameter of the bag-shaped body 30 in the state where the inner surface of the bag-shaped body 30 is in contact with the outer surface of the second member 20 and in the state where the second member 20 is located proximal to the proximal end 30p of the bag-shaped body 30 to the above range, the bag-shaped body 30 can be sufficiently expanded in diameter by bringing the inner surface of the bag-shaped body 30 into contact with the outer surface of the second member 20, making it easier to protrude a medical device from the bag-shaped body 30. The upper limit of the ratio of the minimum inner diameter of the bag-shaped body 30 between the state in which the inner surface of the bag-shaped body 30 is in contact with the outer surface of the second member 20 and the state in which the second member 20 is located proximal to the proximal end 30p of the bag-shaped body 30 is not particularly limited, but can be, for example, 100 times or less, 90 times or less, or 80 times or less.

[0073] When the second member 20 is located proximal to the proximal end 30p of the bag-shaped body 30, the minimum inner diameter of the bag-shaped body 30 is preferably 30% or more, more preferably 35% or more, and even more preferably 40% or more of the inner diameter of the first member 10. By setting the lower limit of the ratio between the minimum inner diameter of the bag-shaped body 30 and the inner diameter of the first member 10 within the above range, it is possible to maintain a small minimum inner diameter of the bag-shaped body 30 while securing the lumen of the bag-shaped body 30, making it easier to insert an article such as a guide wire into the bag-shaped body 30. Furthermore, when the second member 20 is located proximal to the proximal end 30p of the bag-shaped body 30, the minimum inner diameter of the bag-shaped body 30 is preferably 70% or less, more preferably 65% ​​or less, and even more preferably 60% or less of the inner diameter of the first member 10. By setting the upper limit of the ratio between the minimum inner diameter of the bag-like body 30 and the inner diameter of the main body 11 to the above range, the minimum inner diameter of the bag-like body 30 tends to be sufficiently small compared to the first member 10. As a result, the bag-like body 30 is less likely to come into contact with the wall of the body cavity, etc., and the ease of insertion of the catheter 1 can be improved.

[0074] When the second member 20 is located proximal to the proximal end 30p of the bag-shaped body 30, the minimum inner diameter of the bag-shaped body 30 can be selected to be an appropriate size, for example, 0.3 mm or more and 2.0 mm or less.

[0075] The minimum outer diameter of the bag-like body 30 when the second member 20 is located proximal to the proximal end 30p of the bag-like body 30 can also be appropriately selected according to the minimum inner diameter of the bag-like body 30, etc. The minimum outer diameter of the bag-like body 30 when the second member 20 is located proximal to the proximal end 30p of the bag-like body 30 can be, for example, 0.31 mm or more and 3.0 mm or less.

[0076] The minimum inner diameter of the bag-shaped body 30 when its inner surface is in contact with the outer surface of the second member 20 can be selected to be an appropriate size depending on the inner diameter of the first member 10, etc. The minimum inner diameter of the bag-shaped body 30 when its inner surface is in contact with the outer surface of the second member 20 can be about the same as the inner diameter of the first member 10, for example, it can be 0.4 mm or more, 0.8 mm or more, 1.2 mm or more, or 4.0 mm or less.

[0077] When the inner surface of the bag-shaped body 30 is in contact with the outer surface of the second member 20, the length of the bag-shaped body 30 in the longitudinal direction x can be appropriately selected, but for example, it can be 1 mm or more and 20 mm or less.

[0078] Figures 1 and 2 show an example of a so-called rapid exchange type (RX type) configuration in which the guidewire 120 is inserted partway from the distal end to the proximal end of the shaft 90. In addition to the rapid exchange type, the catheter 1 of the present invention can also be applied to a so-called over-the-wire type (OTW type) in which the guidewire 120 is inserted from the distal end to the proximal end of the shaft 90.

[0079] As shown in Figure 6, it is preferable that the diameter of the largest circle C2 that contacts the surface of the second member 20 in a cross section perpendicular to the longitudinal direction x with respect to the central axis in the extending direction of the first member 10 is larger than the minimum inner diameter of the bag-like body 30 in its natural state when no external force is applied to it. When the diameter of the largest circle C2 that contacts the surface of the second member 20 is larger than the minimum inner diameter of the bag-like body 30 in its natural state, the second member 20 can easily sufficiently expand the diameter of the bag-like body 30 when the inner surface of the bag-like body 30 and the outer surface of the second member 20 are in contact, making it easier for the medical device placed inside the lumen of the first member 10 to protrude smoothly from the bag-like body 30.

[0080] The diameter of the largest circle C2 that contacts the surface of the second member 20 in a cross section perpendicular to the longitudinal direction x with respect to the central axis in the extending direction of the first member 10 is preferably 1.05 times or more, more preferably 1.1 times or more, and even more preferably 1.3 times or more, the minimum inner diameter of the bag-like body 30 in its natural state when no external force is applied to the first member 10. By setting the lower limit of the ratio between the diameter of the largest circle C2 that contacts the surface of the second member 20 and the minimum inner diameter of the bag-like body 30 in its natural state to the above range, the bag-like body 30 is more likely to expand in diameter when the outer surface of the second member 20 comes into contact with the inner surface of the bag-like body 30. The upper limit of the ratio between the diameter of the largest circle C2 that contacts the surface of the second member 20 and the minimum inner diameter of the bag-like body 30 in its natural state is not particularly limited, but can be, for example, 100 times or less, 90 times or less, or 80 times or less.

[0081] As shown in Figure 2, the first member 10 has a wall forming a lumen, and it is preferable that an insertion passage 14 through which the second member 20 is inserted is formed within the wall of the first member 10. Since the insertion passage 14 is formed within the wall of the first member 10, it is not necessary to provide a separate member to form a path for inserting the second member 20, and thus the diameter of the catheter 1 can be further reduced.

[0082] As shown in Figures 2 and 8, the first member 10 has an outer cylinder 15 and an inner cylinder 16 disposed inside the lumen of the outer cylinder 15, and the insertion passage 14 may be a space partitioned by the inner surface of the outer cylinder 15 and the outer surface of the inner cylinder 16. By having the first member 10 have an outer cylinder 15 and an inner cylinder 16, it becomes unnecessary to provide a separate member for forming the insertion passage 14, and the catheter 1 can be made thinner.

[0083] The thickness of the outer cylinder 15 can be, for example, 0.010 mm or more, 0.015 mm or more, or 0.020 mm or more. Alternatively, the thickness of the outer cylinder 15 can be, for example, 0.500 mm or less, 0.450 mm or less, or 0.400 mm or less.

[0084] The thickness of the inner cylinder 16 can be, for example, 0.010 mm or more, 0.015 mm or more, or 0.020 mm or more. Alternatively, the thickness of the inner cylinder 16 can be, for example, 0.500 mm or less, 0.450 mm or less, or 0.400 mm or less.

[0085] As shown in Figure 7, in a cross section perpendicular to the longitudinal direction x, the distance between the inner surface of the outer cylinder 15 and the outer surface of the inner cylinder 16 is preferably 0.01 mm or more and 1.0 mm or less. By setting the distance between the inner surface of the outer cylinder 15 and the outer surface of the inner cylinder 16 within the above range, it is possible to ensure sufficient width of the insertion passage 14 while preventing the outer diameter of the first member 10 from becoming too large, and to enable smooth movement of the second member 20 in the longitudinal direction x.

[0086] As shown in Figures 2 and 8, it is preferable that the internal space 30C of the bag-like body 30 is in communication with the insertion passage 14. The internal space 30C being in communication with the insertion passage 14 makes it easier to feed the second member 20, which is inserted through the insertion passage 14, into the internal space 30C of the bag-like body 30.

[0087] As shown in Figures 2 and 8, it is preferable that the internal space 30C does not communicate with the lumen of the first member 10. It is also preferable that the internal space 30C does not communicate with the lumen of the bag-like body 30. By ensuring that the internal space 30C does not communicate with the lumen of the first member 10 or the lumen of the bag-like body 30, the movement of the second member 20 inserted into the internal space 30C can be facilitated, and the second member 20 can be prevented from unintentionally entering the lumen of the first member 10 or the lumen of the bag-like body 30.

[0088] As shown in Figures 2, 7, and 9, it is preferable that the first member 10 has a radiopaque portion 40 in at least one of the following regions: region A1, which extends 10 cm proximal to the proximal end 30p of the bag-shaped body 30, and region A2, which extends 10 cm proximal to the distal end 20d of the second member 20. Having a radiopaque portion 40 in at least one of region A1 and region A2 makes it possible to visualize the position of the distal end of the catheter 1 using an X-ray imaging device.

[0089] The X-ray opaque portion 40 is a portion containing an X-ray opaque material. Examples of X-ray opaque materials include at least one selected from the group consisting of lead, barium, iodine, tungsten, gold, platinum, iridium, stainless steel, titanium, cobalt-chromium alloy, etc.

[0090] The radiopaque portion 40 may include a portion formed from an X-ray opaque substance, or a portion formed by kneading an X-ray opaque substance into a material such as a synthetic resin. In particular, it is preferable that the radiopaque portion 40 is formed by an X-ray opaque marker containing an X-ray opaque substance. Because the radiopaque portion 40 is an X-ray opaque marker, it is possible to accurately form the radiopaque portion 40 at the desired position during the manufacture of the catheter 1.

[0091] The shape of the X-ray opaque marker that forms the X-ray opaque area 40 can be cylindrical, polygonal, C-shaped with a notch in the tube, or a coil shape formed by winding a wire. Among these, the shape of the X-ray opaque marker is preferably cylindrical. The cylindrical shape of the X-ray opaque marker improves the visibility of the X-ray opaque area 40 by the X-ray imaging device.

[0092] The number of radiopaque portions 40 located in region A1 of the bag-shaped body 30 of the first member 10, from the proximal end 30p to 10 cm proximal, may be one or multiple. Similarly, the number of radiopaque portions 40 located in region A2 of the second member 20, from the distal end 20d to 10 cm proximal, may also be one or multiple.

[0093] It is preferable that the radiopaque portion 40 is located in region A1, which extends 10 cm proximal to the proximal end 30p of the bag-like body 30 in the first member 10, and in region A2, which extends 10 cm proximal to the distal end 20d of the second member 20. In other words, it is preferable that the radiopaque portion 40 is located in both region A1 and region A2. By having the radiopaque portion 40 in both region A1 and region A2, the position of the distal ends of both the first member 10 and the second member 20 can be confirmed by the X-ray imaging device, making the procedure easier to perform.

[0094] As shown in Figures 2, 7, and 9, it is preferable that the number of radiopaque portions 40 located in region A2 from the distal end 20d of the second member 20 to 10 cm proximal is greater than the number of radiopaque portions 40 located in region A1 from the proximal end 30p of the bag-shaped body 30 of the first member 10 to 10 cm proximal. Having more radiopaque portions 40 in region A2 than in region A1 makes it easier to confirm the position of the distal end of the catheter 1 using an X-ray imaging device.

[0095] As shown in Figures 2, 7, and 9, at least the bag-shaped body 30 is provided with a first shape memory member 51, and the elasticity of the first shape memory member 51 is higher than that of the bag-shaped body 30. Preferably, in a natural state where no external force is applied to the first shape memory member 51, the diameter of the smallest circle tangent to the surface of the first shape memory member 51 in a cross section perpendicular to the longitudinal direction x centered on the central axis in the extending direction of the first member 10 is smaller than the inner diameter of the first member 10. Here, elasticity refers to the magnitude of strain at the elastic limit, and high elasticity means that even if a large strain is applied, it returns to its original shape and has a large restoring force. The first shape memory member 51 has higher elasticity than the bag-shaped body 30, and even if an external force is applied to the first shape memory member 51 and it is deformed, it easily returns to the shape of the first shape memory member 51 in its natural state once the external force applied to the first shape memory member 51 is removed. Since the first shape memory member 51 is provided at least on the bag-shaped body 30, as the area in contact between the outer surface of the second member 20 and the inner surface of the bag-shaped body 30 decreases, for example by pushing the first member 10 toward the treatment part, the bag-shaped body 30 becomes easier to shrink in diameter due to the first shape memory member 51, making it easier to close the bag-shaped body 30.

[0096] Examples of materials that constitute the first shape memory member 51 include stainless steel such as SUS304 and SUS316, shape memory alloys such as Ni-Ti alloys, and shape memory resins. Among these, the material constituting the first shape memory member 51 is preferably a shape memory alloy, and more preferably a Ni-Ti alloy. By using a Ni-Ti alloy as the material constituting the first shape memory member 51, the first shape memory member 51 exhibits excellent shape memory properties and elasticity.

[0097] In a natural state where no external force is applied to the first shape memory member 51, the diameter of the smallest circle that contacts the surface of the first shape memory member 51 in a cross section perpendicular to the longitudinal direction x centered on the central axis in the extending direction of the first member 10 is preferably 99% or less, more preferably 97% or less, and even more preferably 95% or less of the inner diameter of the first member 10. By setting the upper limit of the ratio between the diameter of the smallest circle that contacts the surface of the first shape memory member 51 in a natural state and the inner diameter of the first member 10 to the above range, the bag-shaped body 30 can be easily reduced in diameter by the first shape memory member 51. Furthermore, in a natural state where no external force is applied to the first shape memory member 51, the diameter of the smallest circle that contacts the surface of the first shape memory member 51 in a cross section perpendicular to the longitudinal direction x centered on the central axis in the extending direction of the first member 10 is preferably 1% or more, more preferably 3% or more, and even more preferably 5% or more of the inner diameter of the first member 10. By setting the lower limit of the ratio between the diameter of the smallest circle that contacts the surface of the first shape memory member 51 in its natural state and the inner diameter of the first member 10 to the above range, the diameter of the smallest circle that contacts the surface of the first shape memory member 51 in its natural state does not become too small, making it easier to smoothly move the first member 10 in the longitudinal direction x relative to the second member 20.

[0098] It is preferable that the first shape memory member 51 is provided across both the bag-shaped body 30 and the first member 10. By providing the first shape memory member 51 on both the bag-shaped body 30 and the first member 10, when an external force is applied to the first shape memory member 51 to deform it and then the external force is removed from the first shape memory member 51, the first shape memory member 51 is more likely to return to its original shape, making it easier to reduce the diameter of the bag-shaped body 30.

[0099] As shown in Figures 2, 7, and 9, the second member 20 has a second shape memory section 52 at least in its distal portion. Preferably, the diameter of the largest circle tangent to the surface of the second shape memory section 52 in a cross section perpendicular to the longitudinal direction x centered on the central axis in the extending direction of the first member 10, when no external force is applied to the second shape memory section 52 in its natural state, is larger than the diameter of the largest circle tangent to the surface of the second member 20 in a cross section perpendicular to the longitudinal direction x centered on the central axis in the extending direction of the first member 10. Even if the second shape memory section 52 is deformed by applying an external force, it is easy for it to return to its natural shape when the external force applied to the second shape memory section 52 is removed. Because the second member 20 has a second shape memory portion 52 at least in its distal portion, the second shape memory portion 52 makes it easier for the diameter of the largest circle tangent to the surface of the second member 20 in a cross section perpendicular to the longitudinal direction x, centered on the central axis in the extending direction of the first member 10 in its natural state, to increase. Therefore, the second member 20 makes it easier to expand the diameter of the bag-like body 30.

[0100] The second shape memory section 52 is provided at least distal to the second member 20 and may be a separate member from the second member 20, or it may be at least a part of the second member 20. The entire second member 20 may also be the second shape memory section 52.

[0101] Examples of materials that constitute the second shape memory section 52 include stainless steel such as SUS304 and SUS316, shape memory alloys such as Ni-Ti alloys, and shape memory resins. Among these, the material constituting the second shape memory section 52 is preferably a shape memory alloy, and more preferably a Ni-Ti alloy. By using a Ni-Ti alloy as the material constituting the second shape memory section 52, it is possible to obtain a second shape memory section 52 with excellent shape memory properties and elasticity.

[0102] In a natural state where no external force is applied to the second shape memory section 52, the diameter of the largest circle tangent to the surface of the second shape memory section 52 in a cross section perpendicular to the longitudinal direction x centered on the central axis in the extending direction of the first member 10 is preferably 1.1 times or more, more preferably 1.2 times or more, and even more preferably 1.3 times or more, the diameter of the largest circle tangent to the surface of the second member 20 in a cross section perpendicular to the longitudinal direction x centered on the central axis in the extending direction of the first member 10. By setting the lower limit of the ratio between the diameter of the largest circle tangent to the surface of the second shape memory section 52 in a natural state and the diameter of the largest circle tangent to the surface of the second member 20 within the above range, it is possible to make it easier to increase the diameter of the largest circle tangent to the surface of the second member 20 in a natural state. Furthermore, in a natural state where no external force is applied to the second shape memory section 52, the diameter of the largest circle tangent to the surface of the second shape memory section 52 in a cross section perpendicular to the longitudinal direction x centered on the central axis in the extending direction of the first member 10 is preferably 100 times or less, more preferably 90 times or less, and even more preferably 80 times or less, the diameter of the largest circle tangent to the surface of the second member 20 in a cross section perpendicular to the longitudinal direction x centered on the central axis in the extending direction of the first member 10. By setting the upper limit of the ratio between the diameter of the largest circle tangent to the surface of the second shape memory section 52 and the diameter of the largest circle tangent to the surface of the second member 20 in a natural state to the above range, the diameter of the largest circle tangent to the surface of the second shape memory section 52 does not become too large, and the movement of the first member 10 in the longitudinal direction x relative to the second member 20 becomes smoother.

[0103] As shown in Figures 2, 7, and 9, the second member 20 preferably has a lumen extending in the longitudinal direction x. That is, as shown in Figures 3 and 4, the second member 20 preferably has a cylindrical shape. By having a lumen in the second member 20, the contact area between the outer surface of the second member 20 and the inner surface of the bag-like body 30 can be increased.

[0104] If the second member 20 is a cylindrical body, the second member 20 can be composed of a single layer or multiple layers. The second member 20 may be composed of a single layer in part in the longitudinal direction x or in the circumferential direction, and the other part may be composed of multiple layers.

[0105] As shown in Figures 2 and 7, the catheter 1 further has a first linear member 61, and it is preferable that the first linear member 61 is fixed to the proximal part of the first member 10. The presence of the first linear member 61 fixed to the proximal part of the first member 10 in the catheter 1 makes it easier to pull the first member 10 proximal. By pulling the first member 10 proximal, the distal end 20d of the second member 20 is moved distally, and the bag-like body 30 can be expanded in diameter by the second member 20.

[0106] The first linear member 61 is a long wire. The wire constituting the first linear member 61 may be a single wire or a stranded wire consisting of multiple single wires.

[0107] The material constituting the first linear member 61 is preferably a metal such as stainless steel, titanium, nickel-titanium alloy, cobalt-chromium alloy, or tungsten alloy, and more preferably stainless steel or a tungsten alloy. Because the material constituting the first linear member 61 is a metal, the first linear member 61 can be made both flexible and highly rigid, making it easier to pull the first linear member 61 even in a curved body cavity.

[0108] The length of the first linear member 61 in the longitudinal direction x only needs to be long enough to be operable from the user's hand, and an appropriate length can be selected as needed.

[0109] Examples of cross-sectional shapes for the first linear member 61 perpendicular to the longitudinal direction x include square, rectangular, trapezoidal, and circular shapes. Among these, the cross-sectional shape of the first linear member 61 perpendicular to the longitudinal direction x is preferably circular. By having a circular cross-sectional shape, even if the first linear member 61 comes into contact with another object when pulling the first linear member 61, it is less likely that the first linear member 61 will damage the other object.

[0110] The outer diameter of the first linear member 61 can be, for example, 0.2 mm or more and 1.0 mm or less. If the cross-sectional shape of the first linear member 61 perpendicular to the longitudinal direction x is polygonal, the outer diameter of the first linear member 61 refers to the diameter of the circumscribed circle of the cross-sectional shape of the first linear member 61.

[0111] Methods for fixing the first linear member 61 to the proximal part of the first member 10 include, for example, welding by laser, brazing, crimping, bonding with adhesives such as acrylic, epoxy, or urethane, and fixing with heat shrink tubing. In particular, it is preferable that the first linear member 61 is fixed to the proximal part of the first member 10 by bonding with an adhesive. By fixing the first linear member 61 to the proximal part of the first member 10 by bonding with an adhesive, the bonding strength between the first linear member 61 and the first member 10 can be easily increased.

[0112] Although not shown in the figures, it is preferable that a gripping portion is provided on the proximal side of the first linear member 61. Examples of materials that make up the gripping portion include synthetic resins such as polyethylene and polyolefin resins such as polypropylene.

[0113] As shown in Figures 2 and 7, the catheter 1 further includes a cylindrical member 82 whose maximum outer diameter is smaller than the maximum outer diameter of the first member 10, the distal part of the cylindrical member 82 is fixed to the proximal part of the second member 20, and the first linear member 61 is preferably positioned in the lumen of the cylindrical member 82. Because the first linear member 61 is positioned in the lumen of the cylindrical member 82, the first linear member 61 is less likely to be exposed to the outside. Therefore, the first linear member 61 is less likely to get tangled or caught on other objects, and the first linear member 61 can be smoothly pulled towards the proximal side.

[0114] The cylindrical member 82 is a cylindrical member having a lumen, and its maximum outer diameter is smaller than the maximum outer diameter of the first member 10. The minimum outer diameter of the cylindrical member 82 may be smaller than the minimum outer diameter of the first member 10.

[0115] The material constituting the cylindrical member 82 may be the same synthetic resin or metal as the material constituting the second member 20. The material constituting the cylindrical member 82 may be different from the material constituting the second member 20, but it is preferable that it be the same material as the material constituting the second member 20. By using the same material as the material constituting the second member 20, it is possible to increase the strength of the fixation between the cylindrical member 82 and the second member 20.

[0116] The length of the cylindrical member 82 in the longitudinal direction x can be selected appropriately according to the length of the first linear member 61 placed in the lumen of the cylindrical member 82 in the longitudinal direction x. For example, the length of the cylindrical member 81 in the longitudinal direction x can be 100 mm or more and 2400 mm or less.

[0117] The outer diameter of the cylindrical member 82 can be appropriately selected as needed, for example, it can be 0.6 mm or more and 3.0 mm or less. In particular, the outer diameter of the cylindrical member 82 is preferably 0.6 mm or more and 1.0 mm or less. By setting the outer diameter of the cylindrical member 82 within the above range, it is possible to prevent the outer diameter of the cylindrical member 82 from becoming too large and to prevent the outer diameter of the catheter 1 from becoming too large in accordance with the outer diameter of the cylindrical member 82.

[0118] The inner diameter of the cylindrical member 82 can be, for example, 0.3 mm or more and 2.5 mm or less. In particular, the inner diameter of the cylindrical member 82 is preferably 0.5 mm or more and 0.9 mm or less. By setting the inner diameter of the cylindrical member 82 within the above range, it becomes easier to insert the first linear member 61 into the lumen of the cylindrical member 82, and it is possible to keep the outer diameter of the cylindrical member 82 small.

[0119] As shown in Figure 9, the catheter 1 further has a second linear member 62, and it is preferable that the second linear member 62 is fixed to the proximal part of the second member 20. The catheter 1 having a second linear member 62 fixed to the proximal part of the second member 20 makes it easier to push the second member 20 toward the treatment area. By pushing the second member 20 toward the treatment area, the second member 20 is moved toward the distal side, the outer surface of the second member 20 comes into contact with the inner surface of the bag-like body 30, and the bag-like body 30 can be sufficiently expanded in diameter.

[0120] The second linear member 62 is a long wire. The wire constituting the second linear member 62 may be a single wire or a stranded wire consisting of multiple single wires.

[0121] The material constituting the second linear member 62 is preferably a metal such as stainless steel, titanium, nickel-titanium alloy, cobalt-chromium alloy, or tungsten alloy, and more preferably stainless steel or a tungsten alloy. Because the material constituting the second linear member 62 is metal, it is possible to create a second linear member 62 that is flexible and highly rigid, making it easier to press even in a curved body cavity.

[0122] The length x in the longitudinal direction of the second linear member 62 can be any length that allows it to be operated from the user's hand, or a length that allows it to be inserted into the lumen of the cylindrical member 81 described later, and an appropriate length can be selected as needed.

[0123] Examples of cross-sectional shapes for the second linear member 62 perpendicular to the longitudinal direction x include square, rectangular, trapezoidal, and circular shapes. Among these, the cross-sectional shape of the second linear member 62 perpendicular to the longitudinal direction x is preferably circular. The circular cross-sectional shape of the second linear member 62 makes it less likely for the second linear member 62 to damage other objects when it comes into contact with them, such as when it is pressed.

[0124] The outer diameter of the second linear member 62 can be, for example, 0.2 mm or more and 1.0 mm or less. If the cross-sectional shape of the second linear member 62 perpendicular to the longitudinal direction x is polygonal, the outer diameter of the second linear member 62 refers to the diameter of the circumscribed circle of the cross-sectional shape of the second linear member 62.

[0125] Methods for fixing the second linear member 62 to the proximal part of the second member 20 include, for example, welding by laser, brazing, crimping, bonding with adhesives such as acrylic, epoxy, or urethane, and fixing with heat shrink tubing. Among these, it is preferable that the second linear member 62 is fixed to the proximal part of the second member 20 by bonding with an adhesive. By fixing the second linear member 62 to the proximal part of the second member 20 by bonding with an adhesive, the bonding strength between the second linear member 62 and the second member 20 can be easily increased.

[0126] Although not shown in the figures, it is preferable that a gripping portion is provided on the proximal side of the second linear member 62. Examples of materials that make up the gripping portion include synthetic resins such as polyethylene and polyolefin resins such as polypropylene.

[0127] As shown in Figure 9, the catheter 1 further has a cylindrical member 81 whose maximum outer diameter is smaller than the maximum outer diameter of the first member 10, the distal part of the cylindrical member 81 is fixed to the proximal part of the first member 10, and the second linear member 62 is preferably positioned in the lumen of the cylindrical member 81. By positioning the second linear member 62 in the lumen of the cylindrical member 81, the second linear member 62 is less likely to be exposed to the outside, making it less likely for the second linear member 62 to become entangled or caught on other objects, and allowing the second linear member 62 to be smoothly pushed toward the treatment area.

[0128] Methods for fixing the distal portion of the cylindrical member 81 to the proximal portion of the first member 10 include, for example, welding by laser, brazing, riveting, and bonding with adhesives such as acrylic, epoxy, or urethane. In particular, it is preferable that the distal portion of the cylindrical member 81 is fixed to the proximal portion of the first member 10 by bonding with an adhesive. By fixing the distal portion of the cylindrical member 81 to the proximal portion of the first member 10 by bonding with an adhesive, it becomes possible to easily and firmly fix the cylindrical member 81 and the first member 10.

[0129] The cylindrical member 81 is a cylindrical member having a lumen, and its maximum outer diameter is smaller than the maximum outer diameter of the first member 10. The minimum outer diameter of the cylindrical member 81 may be smaller than the minimum outer diameter of the first member 10.

[0130] The material constituting the cylindrical member 81 may be the same synthetic resin or metal as the material constituting the first member 10. The material constituting the cylindrical member 81 may be different from the material constituting the first member 10, but it is preferable that it be the same material as the material constituting the first member 10. By using the same material as the material constituting the first member 10, it is possible to increase the strength of the fixation between the cylindrical member 81 and the first member 10.

[0131] The length of the cylindrical member 81 in the longitudinal direction x can be selected appropriately according to the length of the second linear member 62 placed in the lumen of the cylindrical member 81 in the longitudinal direction x. For example, the length of the cylindrical member 81 in the longitudinal direction x can be 100 mm or more and 2400 mm or less.

[0132] The outer diameter of the cylindrical member 81 can be appropriately selected as needed, for example, it can be 0.6 mm or more and 3.0 mm or less. In particular, the outer diameter of the cylindrical member 81 is preferably 0.6 mm or more and 1.0 mm or less. By setting the outer diameter of the cylindrical member 81 within the above range, it is possible to prevent the outer diameter of the cylindrical member 81 from becoming too large and to prevent the outer diameter of the catheter 1 from becoming too large in accordance with the outer diameter of the cylindrical member 81.

[0133] The inner diameter of the cylindrical member 81 can be, for example, 0.3 mm or more and 2.5 mm or less. In particular, the inner diameter of the cylindrical member 81 is preferably 0.5 mm or more and 0.9 mm or less. By setting the inner diameter of the cylindrical member 81 within the above range, it becomes easier to insert the second linear member 62 into the lumen of the cylindrical member 81, and it is possible to keep the outer diameter of the cylindrical member 81 small.

[0134] The tubular members 81 and 82 may have a lubricating coating on their outer surfaces. Fluorine-based resins such as PTFE, PFA, and ETFE can be used as the lubricating coating. The lubricating coating on the outer surfaces of the tubular members 81 and 82 increases their slipperiness, thereby improving the ease of insertion of the catheter 1.

[0135] Although not shown in the diagram, position markers may be provided on the tubular members 81 and 82 to confirm the length of catheter 1 inserted into the body cavity. Methods for providing position markers on the tubular members 81 and 82 include, for example, placing markers on the tubular members 81 and 82, or partially peeling off the coating applied to the outer surface of the tubular members 81 and 82. Multiple position markers can be present on the tubular members 81 and 82. Specifically, for example, if the length x in the longitudinal direction of catheter 1 is 2400 mm, a configuration may be provided in which position markers are provided at a position 600 mm proximal to the distal end of catheter 1, a position 900 mm proximal to the distal end, and a position 1200 mm proximal to the distal end.

[0136] As shown in Figures 2, 3, 7, and 9, it is preferable that the second member 20 has a second diameter reduction region 72 in the proximal part of the second member 20, in which the length in the radial direction y, when observed from a direction perpendicular to the longitudinal direction x, becomes shorter towards the proximal side. Having the second diameter reduction region 72 of the second member 20 increases the flexibility of the second member 20, making it easier to bend the second member 20 along a curved body cavity.

[0137] The length of the second diameter reduction region 72 in the longitudinal direction x is preferably 50% or less of the length of the second member 20, more preferably 40% or less, and even more preferably 30% or less. By setting the upper limit of the ratio between the length of the second diameter reduction region 72 and the length of the second member 20 within the above range, the rigidity of the second member 20 can be maintained, and the insertion of the catheter 1 can be improved. Furthermore, the length of the second diameter reduction region 72 in the longitudinal direction x is preferably 2% or more of the length of the second member 20, more preferably 4% or more, and even more preferably 6% or more. By setting the lower limit of the ratio between the length of the second diameter reduction region 72 and the length of the second member 20 within the above range, the flexibility of the second member 20 can be increased, making the second member 20 more flexible.

[0138] As shown in Figures 1, 2, 7, and 9, the first member 10 can be configured to have a first diameter reduction region 71 in the proximal part of the first member 10, in which the length in the radial direction y, when observed from a direction perpendicular to the longitudinal direction x, becomes shorter towards the proximal side. The presence of the first diameter reduction region 71 in the first member 10 increases the flexibility of the first member 10, making it easier for the first member 10 to bend to conform to a curved body cavity.

[0139] The length of the first diameter reduction region 71 in the longitudinal direction x is preferably 50% or less of the length of the first member 10, more preferably 40% or less, and even more preferably 30% or less. By setting the upper limit of the ratio between the length of the first diameter reduction region 71 and the length of the first member 10 within the above range, the rigidity of the first member 10 can be maintained and the insertion of the catheter 1 can be improved. Furthermore, the length of the first diameter reduction region 71 in the longitudinal direction x is preferably 2% or more of the length of the first member 10, more preferably 4% or more, and even more preferably 6% or more. By setting the lower limit of the ratio between the length of the first diameter reduction region 71 and the length of the first member 10 within the above range, the flexibility of the first member 10 can be increased, making it easier to bend the first member 10.

[0140] As shown in Figure 1, it is preferable that the catheter 1 further has a hub 110 at the proximal end of the first member 10 or at the tubular members 81, 82. The hub 110 has a port inside that communicates with the lumen of the first member 10 or the tubular members 81, 82, and is used when introducing a material or fluid into the lumen of the first member 10 or the tubular members 81, 82. The hub 110 may be directly connected to the proximal end 10p of the first member 10 or the proximal end of the tubular members 81, 82, or it may be indirectly connected to the proximal end 10p of the first member 10 or the proximal end of the tubular members 81, 82 via another member.

[0141] Figure 10 is a cross-sectional view parallel to the longitudinal direction x of a catheter 1 according to yet another embodiment of the present invention. As shown in Figure 10, the catheter can be configured to include a shaft 90 positioned within the lumen of the first member 10 so as to be movable relative to the first member 10, and an expansion member 100 provided at the distal end of the shaft 90 and expanding in the radial direction y.

[0142] The shaft 90 can be configured to have a lumen extending in the longitudinal direction x. The lumen of the shaft 90 can be used as an insertion passage for a guidewire 120 or the like, as shown in Figure 10.

[0143] The material constituting the shaft 90 may be the same synthetic resin or metal as the material constituting the first member 10. The material constituting the shaft 90 may be the same material as the material constituting the first member 10, or it may be a different material from the material constituting the first member 10.

[0144] For example, a balloon or a stent can be used as the expansion member 100.

[0145] The balloon is preferably made of resin. Examples of resins that make up the balloon include polyamide resins, polyester resins, polyurethane resins, polyolefin resins, vinyl chloride resins, silicone resins, and natural rubber. These may be used individually or in combination of two or more. Among these, polyamide resins, polyester resins, and polyurethane resins are preferably used as the resins that make up the balloon. Elastomer resins can be used from the viewpoint of thinning the balloon and improving its flexibility.

[0146] A stent is an expandable structure composed of a mesh or other network structure, and includes multiple support columns. A stent can be formed from a pattern of interconnected structural elements that expand and contract in the circumferential and axial directions. Examples of stents include coils made of a single linear metal or polymer material, tubes made of metal or polymer material cut out with a laser, stents assembled by welding linear parts, and stents constructed by weaving multiple linear metals together.

[0147] The stent is preferably made of a shape memory alloy or shape memory resin. The stent can be expanded smoothly if it is made of a shape memory alloy or shape memory resin. The stent may be made of, for example, stainless steel such as SUS304 or SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, aluminum, gold, silver, Ni-Ti alloy, Co-Cr alloy, etc.

[0148] The stent may be a self-expanding stent or a balloon-expanding stent.

[0149] The catheter 1 may be further configured to include a control mechanism that suppresses the movement of the shaft 90 in the longitudinal direction x within the lumen of the first member 10. Because the catheter 1 is equipped with a control mechanism, the movement of the shaft 90 in the longitudinal direction x within the lumen of the first member 10 is suppressed by the control mechanism, allowing the catheter 1 to be transported to the treatment area, thus facilitating the transport of the catheter 1 to the treatment area.

[0150] Although not shown in the figures, one possible control mechanism is one in which a gripping member capable of gripping the shaft 90 is provided on the first member 10. By providing the gripping member on the first member 10, the shaft 90 can be gripped by the gripping member, and its movement in the longitudinal direction x within the lumen of the first member 10 can be temporarily suppressed. Then, by releasing the shaft 90 from the gripping member, the shaft 90 can be returned to a state in which it can move relative to the first member 10. Examples of gripping members include a rubber member with a slit for gripping the shaft 90, a clip made of synthetic resin, and so on.

[0151] The expansion member 100 is preferably a balloon or stent with a coating layer formed on its outer surface. Having a coating layer on its outer surface increases the slipperiness of the outer surface of the expansion member 100, making it easier to release the expansion member 100 from the bag-like body 30.

[0152] The coating layer can be formed by applying a coating agent to the outer surface of the balloon or stent. The coating layer may be formed on only a portion of the outer surface of the balloon or stent, or on the entire outer surface of the balloon or stent. The coating layer may contain a lubricating coating agent or a bioactive agent.

[0153] Examples of lubricating coating agents include silicone-based coating agents such as silicone and polydimethylsiloxane; acrylic-based coating agents such as sodium (meth)acrylate, butyl (meth)acrylate, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, octyl (meth)acrylate, and 2,2,2-trifluoroethyl methacrylate; fluorine-based coatings such as polytetrafluoroethylene; and hydrophilic coating agents such as polyvinylpyrrolidone, hyaluronic acid, and polyethylene glycol.

[0154] Examples of physiologically active agents include paclitaxel, docetaxel, sirolimus, temsirolimus, everolimus, zotarolimus, biolimus A9, cilostazol, cyclosporine, and NF-κB decoy oligos. These physiologically active agents may be used individually or in combination. Furthermore, the physiologically active substance may be used alone to coat the balloon or stent, or additives may be used in combination as appropriate.

[0155] The coating layer preferably contains a bioactive agent. The inclusion of a bioactive agent in the coating layer of the balloon or stent enhances the efficiency of treatment when the balloon or stent is placed at the treatment site using catheter 1.

[0156] Catheter 1 may further include a controller for catheter 1, devices used with catheter 1, a hub, etc. Although not shown in the figures, catheter 1 may be configured to have a locking mechanism at its proximal end for securing the controller, device, hub, etc.

[0157] The length x in the longitudinal direction of catheter 1 can be selected as appropriate. For example, the length x in the longitudinal direction of catheter 1 can be between 200 mm and 2500 mm. [Explanation of symbols]

[0158] 1: Catheter 10: First component 10d: Distal end of the first member 10p: Proximal end of the first member 11: Main body 11d: Distal end of the main body 14: Insertion passage 15: Outer cylinder 16: Inner cylinder 20: Second component 20d: Distal end of the second member 30: Bag-like body 30d: Distal end of the sac-like structure 30p: Proximal end of the sac-like structure 40:X-ray opaque area 51: First shape memory member 52:Second shape memory section 61: First linear member 62: Second linear member 71: 1st diameter reduction area 71p: Proximal end of the first diameter reduction region 72:Second diameter reduction area 81: Cylindrical member 82: Cylindrical member 90: Shaft 100: Expansion member 110: Hub 120: Guidewire x: Longest direction y: radial direction C2: The largest circle tangent to the surface of the second member in a cross section perpendicular to the longitudinal direction, centered on the central axis in the extending direction of the first member. A1: Region of the first member from the proximal end of the bag-like body to 10 cm proximal. A2: The region from the distal end of the second member to 10 cm proximal.

Claims

1. A first member having a distal end and a proximal end, and a lumen extending in the longitudinal direction, A bag-like body is provided at the distal end of the first member, is formed in an annular shape, has an outer surface, an inner surface and an internal space, and has an inner diameter smaller than the inner diameter of the first member, It comprises a second member disposed in the internal space of the bag-like body, The first member is movable in the longitudinal direction relative to the second member, The first member has a wall forming a lumen, and an insertion passage is formed within the wall of the first member through which the second member is inserted. The aforementioned internal space is in communication with the aforementioned insertion passage. In the state in which the second member is arranged inside the bag-like body, at least a portion of the surface of the bag-like body on the internal space side is in contact with the surface of the second member. A catheter in which the minimum inner diameter of the bag-like body when the inner surface of the bag-like body and the outer surface of the second member are in contact is greater than the minimum inner diameter of the bag-like body when the second member is located proximal to the proximal end of the bag-like body.

2. The catheter according to claim 1, wherein the diameter of the largest circle tangent to the surface of the second member in a cross section perpendicular to the longitudinal direction with respect to the central axis in the extending direction of the first member is greater than the minimum inner diameter of the bag-shaped body in a natural state where no external force is applied to the bag-shaped body.

3. The first member comprises an outer cylinder and an inner cylinder disposed within the inner cavity of the outer cylinder. The catheter according to claim 1 or 2, wherein the insertion passage is a space partitioned by the inner surface of the outer cylinder and the outer surface of the inner cylinder.

4. The catheter according to any one of claims 1 to 3, wherein the internal space is not in communication with the lumen of the first member.

5. The catheter according to any one of claims 1 to 4, wherein at least one of the regions of the first member from the proximal end to 10 cm proximal to the bag-like body and the region of the second member from the distal end to 10 cm proximal to the body is radiopaque.

6. The catheter according to claim 5, wherein the number of radiopaque portions arranged in the region from the distal end of the second member to 10 cm proximal is greater than the number of radiopaque portions arranged in the region from the proximal end of the bag-shaped body of the first member to 10 cm proximal.

7. At least the bag-like body is provided with a first shape memory member, The elasticity of the first shape memory member is higher than that of the bag-shaped body. The catheter according to any one of claims 1 to 6, wherein, in a natural state where no external force is applied to the first shape memory member, the inner diameter of the smallest circle tangent to the surface of the first shape memory member in a cross section perpendicular to the longitudinal direction centered on the central axis in the extending direction of the first member is smaller than the inner diameter of the first member.

8. The second member has at least a second shape memory portion at its distal portion, The catheter according to any one of claims 1 to 7, wherein the diameter of the largest circle tangent to the surface of the second shape memory in a cross section perpendicular to the longitudinal direction centered on the central axis in the extending direction of the first member, in a natural state where no external force is applied to the second shape memory, is greater than the diameter of the largest circle tangent to the surface of the second member in a cross section perpendicular to the longitudinal direction centered on the central axis in the extending direction of the first member.

9. The catheter according to any one of claims 1 to 8, wherein the second member has a lumen extending in the longitudinal direction.

10. It has a first linear member, The catheter according to any one of claims 1 to 9, wherein the first linear member is fixed to the proximal portion of the first member.

11. The present invention further comprises a cylindrical member whose maximum outer diameter is smaller than the maximum outer diameter of the first member, The distal portion of the cylindrical member is fixed to the proximal portion of the second member. The catheter according to claim 10, wherein the first linear member is disposed in the lumen of the cylindrical member.

12. It has a second linear member, The catheter according to any one of claims 1 to 11, wherein the second linear member is fixed to the proximal portion of the second member.

13. The present invention further comprises a cylindrical member whose maximum outer diameter is smaller than the maximum outer diameter of the first member, The distal portion of the cylindrical member is fixed to the proximal portion of the first member. The catheter according to claim 12, wherein the second linear member is disposed in the lumen of the cylindrical member.

14. The catheter according to claim 9, wherein the second member has a second diameter reduction region in the proximal portion of the second member, in which the radial length when observed from a direction perpendicular to the longitudinal direction is shortened toward the proximal side.

15. The catheter according to any one of claims 1 to 14, wherein the first member has a first diameter reduction region in the proximal part of the first member, the radial length when observed from a direction perpendicular to the longitudinal direction is shortened towards the proximal side.

16. A shaft is disposed within the lumen of the first member in a manner that allows it to move relative to the first member, The catheter according to any one of claims 1 to 15, further comprising an expansion member provided at the distal end of the shaft and expanding radially.

17. The catheter according to claim 16, further comprising a control mechanism for suppressing longitudinal movement of the shaft within the lumen of the first member.

18. The catheter according to claim 16 or 17, wherein the expansion member is a balloon or stent having a coating layer formed on its outer surface.

19. The catheter according to claim 18, wherein the coating layer contains a bioactive agent.

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