Catheter

Abstract

To provide a catheter that facilitates preventing damages of a wall of a body cavity in being conveyed to a treatment part, and improving passing property in the body cavity.SOLUTION: A catheter 100 includes a first shaft 1 having a first cylindrical part 10, a bag-like body part 20 arranged at a further distal side than the first cylindrical part 10, and formed in an annular shape, a swelling part 30 swelling outward in a radial direction y of the first cylindrical part 10, and a flow channel 40 capable of impregnating fluid to the bag-like body part 20 and the swelling part 30. The catheter 100 is such that: a minimum inner diameter of the bag-like body part 20 when the bag-like body part 20 is in a state of being compressed by impregnation of fluid to the flow channel 40 is larger than a minimum inner diameter of the bag-like body part 20 in a state where compression is not performed by impregnation of fluid to the flow channel 40; and the swelling part 30 swells in a state of being compressed by impregnation of fluid to the flow channel 40, and swells outward in the radial direction y of the first cylindrical part 10.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a catheter. [Background technology]

[0002] For example, a resin tube is used to transport a medical device such as a balloon or a stent to a treatment site, which is a treatment target. Specifically, the medical device is inserted into a body cavity such as a blood vessel while being placed inside the resin tube, and is transported to the treatment site. If the resin tube used at this time has a simple cylindrical shape as described in Patent Document 1, there is a problem that the tip part hits the wall of the body cavity, damaging the wall or reducing passability.

[0003] Patent Document 2 describes a catheter that can prevent damage to the wall of a body cavity. The catheter has a long elastic tubular part with at least one lumen. A soft and deformable tip part is attached to the distal end of the catheter, and the tip part expands in outer diameter and increases the contact area by pressing against a relatively stationary surface. It describes that this makes it possible to reduce the pressure or force per unit area applied to the tissue.

[0004] Patent Document 3 describes a medical technology instrument that is easy to operate. The instrument has a longitudinally elongated tubular variable inner body, a longitudinally elongated outer envelope that surrounds the inner body at least partially on the circumferential side, and a device for changing the instrument from a variable state to a rigid state and vice versa. The inner body is formed in the form of a double tube having an inner tube that forms the inner wall and an outer tube that forms the outer wall and concentrically surrounds the inner tube. The device for changing the instrument from a variable state to a rigid state and vice versa is described as being easy to operate, which applies pressure to the envelope by increasing the pressure in the annular gap to expand the outer tube in the radial direction, thereby changing the instrument to a rigid state. It also describes that the outer diameter of the double tube of the inner body increases, but the size of the internal space of the inner body remains fixed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent No. 9,327,101 [Patent Document 2] Japanese Patent Publication No. 60-040069 [Patent Document 3] Special Publication No. 2009-505700 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the catheter described in Patent Document 2 prevents damage to the wall of the body cavity by expanding the outer diameter of the tip part, and the configuration of the catheter described in Patent Document 2 does not solve the problem that the expanded tip part is prone to getting caught on the wall of the body cavity, making it difficult to pass through the body cavity.

[0007] In addition, the medical technology instrument described in Patent Document 3 improves operability by applying pressure to expand the outer diameter, creating a rigid state, so that the expanded portion is prone to getting caught on the wall of the body cavity, and there is still room for improvement in terms of improving passability through the body cavity.

[0008] In both the catheter of Patent Document 2 and the medical technical instrument of Patent Document 3, it is necessary to transport and place a medical tool such as a balloon or a stent to the treatment site, which is the treatment target. For this reason, the lumen into which the medical tool is inserted needs to have an inner diameter large enough to allow the medical tool to pass from the distal end to the proximal end.

[0009] The present invention has been made in consideration of the above-mentioned circumstances, and its object is to provide a catheter that can easily prevent damage to the wall of a body cavity when transported to a 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 can solve the above problems is as follows. [1] A first tubular portion having a longitudinal direction and an inner cavity extending in the longitudinal direction; A bag-shaped portion located distal to the first tubular portion and formed in an annular shape; A bulging portion that bulges outward in a radial direction of the first cylindrical portion; a flow path through which a fluid can be injected to the bag-shaped body portion and the bulging portion; A catheter having a first shaft comprising: a minimum inner diameter of the bag-shaped body portion when the bag-shaped body portion is pressurized by injection of a fluid into the flow path is larger than a minimum inner diameter of the bag-shaped body portion when the bag-shaped body portion is not pressurized by injection of a fluid into the flow path; The catheter has a bulging portion that bulges outward in the radial direction of the first cylindrical portion when pressurized by injection of fluid into the flow path.

[0011] The catheter can be used in the following manner, for example: after inserting the distal end of the first shaft to a treatment portion, a part of the second shaft having a medical device such as a balloon, a stent, a basket, or a needle disposed in the lumen of the first shaft is protruded from the first shaft. When the first shaft is transported to the treatment portion, the flow path is not pressurized by injecting a fluid. In the state where no pressurization is performed by injecting a fluid into the flow path, the minimum inner diameter of the bag-like body portion is smaller than the minimum inner diameter of the bag-like body portion when the bag-like body portion is pressurized by injecting a fluid into the flow path, so that the outer diameter of the bag-like body portion can be easily reduced. Therefore, when the first shaft is transported to the treatment portion, it is difficult for it to get caught on the wall of the body cavity, and it is easy to prevent damage to the wall of the body cavity, and it is easy to improve the passability through the body cavity. After the first shaft is transported to the treatment portion, the bag-like body portion is pressurized by injecting a fluid into the flow path. The minimum inner diameter of the bag-like body portion in a state where the bag-like body portion is pressurized by injection of a fluid into the flow path is larger than the minimum inner diameter of the bag-like body portion in a state where pressurization by injection of a fluid into the flow path is not performed. This makes it easier to protrude a part of the second shaft disposed in the inner cavity of the first shaft from the expanded bag-like body portion. In addition, after the first shaft is transported to the treatment portion, the bulging portion is brought into a state where it is pressurized by injection of a fluid into the flow path. In a state where the bulging portion is pressurized by injection of a fluid into the flow path, the bulging portion bulges and bulges outward in the radial direction of the first cylindrical portion, making it easier to abut the bulging portion against the wall of the body cavity. This makes it easier to suppress the movement of the first shaft in the body cavity.

[0012] The catheter according to the embodiment of the present invention is preferably any one of the following [2] to

[13] . [2] The bulging portion bulges outward in a radial direction of the first cylindrical portion when the flow path is pressurized to a pressure equal to or greater than a first predetermined pressure by injection of a fluid into the flow path, The catheter described in [1], wherein the minimum inner diameter of the bag-shaped body portion when the bag-shaped body portion is pressurized to a second predetermined pressure or more by injecting a fluid into the flow path is larger than the minimum inner diameter of the bag-shaped body portion when it is not pressurized by injecting a fluid into the flow path. [3] The catheter described in [2], wherein the second predetermined pressure is greater than or equal to the first predetermined pressure. [4] The catheter according to any one of [1] to [3], wherein the fluid injected into the bag-shaped body portion passes through a flow path that allows the fluid to be injected into the bulge portion. [5] The catheter according to any one of [1] to [4], wherein the minimum outer diameter of the bag-shaped portion is smaller than the outer diameter of the first tubular portion. [6] The bag-shaped body portion has an inner surface portion facing an inner cavity of the bag-shaped body portion and an outer surface portion facing an exterior of the bag-shaped body portion, The catheter according to any one of [1] to [5], wherein in a cross section parallel to the longitudinal direction, the angle between the inner surface and the outer surface is an acute angle when no pressure is applied by injecting a fluid into the flow path. [7] The catheter described in any one of [1] to [6], wherein the bag-shaped portion has a tapered portion whose outer diameter becomes smaller toward the distal side. [8] The catheter described in any one of [1] to [7], wherein the bulging height of the bulging portion in the radial direction of the first tubular portion varies in the circumferential direction of the first tubular portion. [9] The catheter described in any one of [1] to [8], wherein the frictional force of the outer surface of the bulge portion is higher than the frictional force of the outer surface of the first tubular portion.

[10] The catheter described in any one of [1] to [9], wherein the bulge portion is located proximal to the proximal end of the bag-shaped portion.

[11] The bag-shaped body portion has an internal space, A catheter as described in [2] or [3], wherein when the bag-shaped body portion is pressurized to a pressure equal to or greater than the second predetermined pressure by injection of fluid into the flow path, in a cross section passing through the central axis of the first tubular portion and along the longitudinal direction, the length of the internal space of the bag-shaped body portion in the radial direction of the first tubular portion decreases from the proximal end to the distal end of the internal space of the bag-shaped body portion.

[12] The bag-shaped body portion has an internal space, A catheter as described in [2] or [3], wherein, in a cross section passing through the central axis of the first tubular portion and along the longitudinal direction when the bag-shaped body portion is pressurized to or above the second predetermined pressure by injection of fluid into the flow path, the length of the internal space of the bag-shaped body portion in the radial direction of the first tubular portion is less than the length of the flow path in the radial direction of the first tubular portion.

[13] Further comprising a second shaft disposed in the inner cavity of the first cylindrical portion, The catheter according to any one of [1] to

[12] , wherein the second shaft comprises a second tubular portion and a diameter expanding / contracting portion fixed to a distal portion of the second tubular portion. Effect of the Invention

[0013] The catheter according to the embodiment of the present invention is such that the first shaft is less likely to get caught on the wall of the body cavity when being transported to the treatment site, and damage to the wall of the body cavity can be easily prevented, and passability through the body cavity can be easily improved. Also, the catheter according to the embodiment of the present invention can easily protrude a part of the second shaft equipped with a medical device such as a balloon, stent, basket, or needle arranged in the inner cavity of the first shaft from the expanded bag-like body part. Furthermore, the catheter according to the embodiment of the present invention can easily suppress movement of the first shaft in the body cavity. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a side view showing an example of a catheter according to an embodiment of the present invention. [Diagram 2]FIG. 2 is an enlarged cross-sectional view of a distal portion of the catheter shown in FIG. [Diagram 3] FIG. 3 is a cross-sectional view of the catheter shown in FIG. 2 taken along line III-III. [Figure 4] FIG. 4 is an enlarged cross-sectional view of a distal portion of the catheter shown in FIG. 1, showing a state in which no pressurization by injection of a fluid is being performed into the flow path. [Diagram 5] FIG. 5 illustrates a cross-sectional view of the catheter shown in FIG. 4 when it has been pressurized by injection of fluid into the flow passage. [Figure 6] FIG. 6 illustrates a cross-sectional view of the catheter shown in FIG. 4 when it has been pressurized by injection of fluid into the flow passage. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII of the catheter shown in FIG. [Figure 8] FIG. 8 is a cross-sectional view showing a modification of the catheter shown in FIG. [Figure 9] FIG. 9 is a cross-sectional view showing a modification of the catheter shown in FIG. [Figure 10] FIG. 10 is a cross-sectional view taken along line XX of the catheter shown in FIG. [Figure 11] FIG. 11 is a cross-sectional view showing a modification of the catheter shown in FIG. [Figure 12] FIG. 12 is a cross-sectional view of the catheter shown in FIG. 11 taken along line XII-XII. [Figure 13] FIG. 13 is a cross-sectional view showing a modification of the catheter shown in FIG. [Figure 14] FIG. 14 is a cross-sectional view taken along line XIV-XIV of the catheter shown in FIG. [Figure 15] FIG. 15 is a cross-sectional view (partially a side view) showing a modification of the catheter shown in FIG. [Figure 16] FIG. 16 is a cross-sectional end view of the catheter shown in FIG. 15 taken along line XVI-XVI. [Figure 17]FIG. 17 shows a cross-sectional view (partially a side view) of the catheter shown in FIG. 15 when it is pressurized by injection of fluid into the flow path. [Figure 18] FIG. 18 shows a cross-sectional view (partially a side view) of the catheter shown in FIG. 15 when it is pressurized by injection of fluid into the flow path. [Figure 19] FIG. 19 is a cross-sectional view showing a modification of the catheter shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The present invention will be described in detail below with reference to the drawings, but the present invention is not limited to the illustrated examples, and can be modified appropriately within the scope of the above and below, and all of these are included in the technical scope of the present invention. In each drawing, hatching and symbols may be omitted for convenience, but in such cases, the specification and other drawings should be referred to. In addition, the dimensions of various parts in the drawings may differ from the actual dimensions, since priority is given to helping understand the features of the present invention.

[0016] One embodiment of the catheter of the present invention is a catheter having a first shaft including a first tubular portion having a longitudinal direction and an inner lumen extending in the longitudinal direction, a bag-shaped body portion located distal to the first tubular portion and formed in a ring shape, a bulging portion bulging radially outward from the first tubular portion, and a flow path through which fluid can be injected up to the bag-shaped body portion and the bulging portion, wherein the minimum inner diameter of the bag-shaped body portion when it is pressurized by injecting fluid into the flow path is larger than the minimum inner diameter of the bag-shaped body portion when it is not pressurized by injecting fluid into the flow path, and the bulging portion bulges and bulges radially outward from the first tubular portion when it is pressurized by injecting fluid into the flow path.

[0017] The overall configuration of a catheter according to an embodiment of the present invention will be described with reference to Figs. 1 to 19. The drawings show a catheter 100 having a first shaft 1 including a first tubular portion 10, a bag-shaped portion 20, a bulging portion 30, and a flow path 40, and a catheter 100 having a second shaft 2 disposed in the lumen 11 of the first tubular portion 10. In the drawings, the longitudinal direction of the first tubular portion 10 is indicated by x, and the radial direction is indicated by y. For ease of understanding, the drawings show an embodiment in which the longitudinal direction x of the first tubular portion 10, the longitudinal direction of the first shaft 1, and the longitudinal direction of the catheter 100 coincide with each other, but the present invention is not limited to this embodiment.

[0018] In this specification, the proximal side refers to the direction toward the user's hand side with respect to the longitudinal direction x of the first cylindrical portion 10, and the distal side refers to the opposite side of the proximal side, i.e., the direction toward the treatment target side. In addition, when each member or each part is divided into two equal parts in the longitudinal direction x of the first cylindrical portion 10, the part located on the distal side of each member or each part is referred to as the distal part of each member or each part, and the part located on the proximal side of each member or each part is referred to as the proximal part of each member or each part. The distal end of each member or each part is the end located on the most distal side of each member or each part. The proximal end of each member or each part is the end located on the most proximal side of each member or each part. The end includes the peripheral part of the end. That is, the distal end refers to the distal end and the peripheral part of the distal end, and the proximal end refers to the proximal end and the peripheral part of the proximal end.

[0019] FIG. 1 is a side view showing an example of a catheter according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a portion of the catheter shown in FIG. 1 located on the distal side. FIG. 3 is a cross-sectional view of the catheter shown in FIG. 2 taken along line III-III. FIG. 4 is an enlarged cross-sectional view of a portion of the catheter shown in FIG. 1 located on the distal side, showing a state in which pressure is not applied by injection of a fluid into the flow path. FIG. 5 is a cross-sectional view of the catheter shown in FIG. 4 when it is pressurized by injection of a fluid into the flow path. FIG. 6 is a cross-sectional view of the catheter shown in FIG. 4 when it is pressurized by injection of a fluid into the flow path. FIG. 7 is a cross-sectional view of the catheter shown in FIG. 6 taken along line VII-VII. FIG. 8 is a cross-sectional view showing a modified example of the catheter shown in FIG. 7. FIG. 9 is a cross-sectional view showing a modified example of the catheter shown in FIG. 7. FIG. 10 is a cross-sectional view of the catheter shown in FIG. 4 taken along line XX. FIG. 11 is a cross-sectional view showing a modified example of the catheter shown in FIG. 4. FIG. 12 is a cross-sectional view of the catheter shown in FIG. 11 taken along line XII-XII. FIG. 13 is a cross-sectional view showing a modified example of the catheter shown in FIG. 4. FIG. 14 is a cross-sectional view taken along line XIV-XIV of the catheter shown in FIG. 13. FIG. 15 is a cross-sectional view (partially a side view) showing a modified example of the catheter shown in FIG. 4. FIG. 16 is a cut end view taken along line XVI-XVI of the catheter shown in FIG. 15. FIG. 17 is a cross-sectional view (partially a side view) showing the catheter shown in FIG. 15 in a state where it is pressurized by injection of a fluid into the flow channel. FIG. 18 is a cross-sectional view (partially a side view) showing the catheter shown in FIG. 15 in a state where it is pressurized by injection of a fluid into the flow channel. FIG. 19 is a cross-sectional view showing a modified example of the catheter shown in FIG. 4.

[0020] 1 to 19, a catheter 100 has a first shaft 1. The first shaft 1 is provided with a first tubular portion 10, a bag-shaped portion 20, a bulging portion 30, and a flow path 40.

[0021] 1, 2, and 4 to 6, the first tubular portion 10 has a longitudinal direction x and has an inner cavity 11 extending in the longitudinal direction x. It is preferable that a gap exists in the inner cavity 11 of the first tubular portion 10.

[0022] As shown in Figs. 2 and 3, the bag-like body portion 20 is a portion having a bag-like shape. Since the bag-like body portion 20 is bag-shaped, it is preferable that the bag-like body portion 20 has an internal space 23 therein. Moreover, the bag-like body portion 20 is a portion formed in an annular shape. Since the bag-like body portion 20 is formed in an annular shape, an inner cavity 25 is formed, and it is preferable that the inner cavity 25 has a gap. The bag-like body portion 20 is located distal to the first tubular portion 10.

[0023] As shown in Figs. 5 to 9, the bulging portion 30 is a portion that bulges outward in the radial direction y of the first tubular portion 10 by expanding.

[0024] As shown in FIGS. 2 and 4 to 19, the flow path 40 is a space into which a fluid can be injected up to the bag-shaped body portion 20 and the bulging portion 30. As shown in FIG.

[0025] 2, the first shaft 1 preferably has an inner cavity formed by communication between the inner cavity 11 of the first tubular portion 10 and the inner cavity 25 of the bag-like portion 20. In the inner cavity of the first shaft 1, a second shaft 2 equipped with a medical device may be disposed.

[0026] Examples of the medical device provided on the second shaft 2 include a balloon, a stent, a basket, a needle, etc. Figures 15 to 18 show an example in which the medical device is provided with an expandable / contractable section 60 that can expand and contract in diameter. The expandable / contractable section 60 includes balloons, stents, and other devices that can expand and contract in diameter.

[0027] 4 and 6, the first shaft 1 is configured so that the minimum inner diameter of the bag-shaped body portion 20 when the bag-shaped body portion 20 is pressurized by injection of a fluid into the flow path 40 is larger than the minimum inner diameter of the bag-shaped body portion 20 when it is not pressurized by injection of a fluid into the flow path 40. This makes the minimum inner diameter of the bag-shaped body portion 20 larger when it is pressurized.

[0028] 5 and 6, the bulging portion 30 is configured to swell and bulge outward in the radial direction y of the first tubular portion 10 when it is pressurized by injection of a fluid into the flow path 40. This causes the bulging portion 30 to bulge outward when it is pressurized.

[0029] The catheter 100 can be used in such a manner that, for example, after the distal end of the first shaft 1 is inserted to a treatment site, a part of the second shaft 2 having a medical device such as a balloon, a stent, a basket, or a needle disposed in the lumen of the first shaft 1 is protruded from the first shaft 1. When the first shaft 1 is transported to the treatment site, it is in a state where pressurization by injection of a fluid into the flow path 40 is not performed, as shown in Figs. 4 and 15. In a state where pressurization by injection of a fluid into the flow path 40 is not performed, the minimum inner diameter of the bag-like body portion 20 is smaller than the minimum inner diameter of the bag-like body portion 20 when the bag-like body portion 20 is in a pressurized state by injection of a fluid into the flow path 40, so that the outer diameter of the bag-like body portion 20 can be easily reduced. Therefore, when the first shaft 1 is transported to the treatment site, it is difficult for it to get caught on the wall of the body cavity, and it is easy to prevent damage to the wall of the body cavity, and it is easy to improve passability through the body cavity. After the first shaft 1 is transported to the treatment portion, the bag-shaped body portion 20 is pressurized by injecting a fluid into the flow path 40 as shown in Figs. 6 and 17. The minimum inner diameter of the bag-shaped body portion 20 in the state in which the bag-shaped body portion 20 is pressurized by injecting a fluid into the flow path 40 is larger than the minimum inner diameter of the bag-shaped body portion 20 in the state in which the pressurization by injecting a fluid into the flow path 40 is not performed. This makes it easier to protrude a part of the second shaft 2 arranged in the inner cavity of the first shaft 1 from the expanded bag-shaped body portion 20. In addition, after the first shaft 1 is transported to the treatment portion, the bulging portion 30 is pressurized by injecting a fluid into the flow path 40 as shown in Figs. 5, 6, 17, and 18. In the state in which the bulging portion 30 is pressurized by injecting a fluid into the flow path 40, the bulging portion 30 bulges outward in the radial direction y of the first cylindrical portion 10, making it easier to abut the bulging portion 30 against the wall of the body cavity. This makes it easier to suppress movement of the first shaft 1 within the body cavity.

[0030] It is preferable that the first tubular portion 10 has flexibility. This allows the first tubular portion 10 to be easily deformed to conform to the shape of the body cavity. In addition, it is preferable that the first tubular portion 10 has elasticity in order to maintain its shape.

[0031] The first cylindrical portion 10 may be a hollow body formed by arranging one or more wires in a predetermined pattern; a hollow body having at least one of the inner surface or outer surface coated with resin; a resin tube; or a combination of these, for example, a combination of these connected in the longitudinal direction. As the hollow body in which the wires are arranged in a predetermined pattern, a cylindrical body having a mesh structure in which the wires are woven, a coil in which the wires are wound, etc. may be used. The wires may be a single wire or a twisted wire. The resin tube may be manufactured by, for example, extrusion molding. When the first cylindrical portion 10 is a resin tube, the resin tube may be a single layer or may have multiple layers. In the longitudinal direction x of the first cylindrical portion 10 or the circumferential direction of the first cylindrical portion 10, a part of the first cylindrical portion 10 may be composed of a single layer, and the other part may be composed of multiple layers.

[0032] The first cylindrical portion 10 can be made of, for example, synthetic resins such as polyolefin resins (e.g., polyethylene and polypropylene), polyamide resins (e.g., nylon), polyester resins (e.g., PET), aromatic polyether ketone resins (e.g., PEEK), polyether polyamide resins, polyurethane resins, polyimide resins, and fluororesins (e.g., PTFE, PFA, and ETFE), or metals such as stainless steel, carbon steel, and nickel-titanium alloys. These may be used alone or in combination of two or more.

[0033] The first cylindrical portion 10 preferably has a distal end 10a and a proximal end 10b. The first cylindrical portion 10 preferably has an inner surface 10c facing the lumen 11 of the first cylindrical portion 10 and an outer surface 10d facing the outside of the first cylindrical portion 10.

[0034] The outer surface 10d of the first tubular portion 10 is preferably coated with a hydrophilic polymer. This makes it easier to insert the first tubular portion 10 into a body cavity. Examples of hydrophilic polymers include poly (2-hydroxyethyl methacrylate), polyacrylamide, polyvinylpyrrolidone, maleic anhydride copolymers such as methyl vinyl ether-maleic anhydride copolymers, and polyethylene glycol.

[0035] The inner surface 10c of the first tubular portion 10 preferably has a portion made of a fluororesin or a polyolefin resin. Only a portion of the inner surface 10c of the first tubular portion 10 may be made of a fluororesin or a polyolefin resin, or the entire inner surface 10c of the first tubular portion 10 may be made of a fluororesin or a polyolefin resin. This makes the first tubular portion 10 more easily slippery with respect to a member disposed in the lumen 11 of the first tubular portion 10, which makes it easier to improve the operability of the catheter 100.

[0036] The outer diameter of the first cylindrical portion 10 can be, for example, 1.0 mm or more, 1.1 mm or more, 1.2 mm or more, etc. Also, the outer diameter of the first cylindrical portion 10 can be, for example, 5.0 mm or less, 4.0 mm or less, 3.0 mm or less, etc., but is preferably 2.0 mm or less.

[0037] The inner diameter of the first cylindrical portion 10 can be, for example, 4.0 mm or less, 3.8 mm or less, 3.5 mm or less, etc. The inner diameter of the first cylindrical portion 10 can be, for example, 0.4 mm or more, 0.5 mm or more, 0.6 mm or more, etc., but is preferably 0.8 mm or more, and more preferably 1.2 mm or more. The inner diameter of the first cylindrical portion 10 is also preferably large enough to allow the second shaft 2 equipped with a medical device to pass through.

[0038] As shown in Figure 2, the first tubular portion 10 has a distal opening 11a at a distal portion of the first tubular portion 10 that connects the inner cavity 11 of the first tubular portion 10 to the outside of the first tubular portion 10, and may have a proximal opening 11b at a proximal portion of the first tubular portion 10 that connects the inner cavity 11 of the first tubular portion 10 to the outside of the first tubular portion 10.

[0039] As shown in Figures 1 and 2, the first tubular portion 10 can be configured to have a tapered region 13 in the proximal portion of the first tubular portion 10, whose length in the radial direction y when observed from a direction perpendicular to the longitudinal direction x of the first tubular portion 10 decreases toward the proximal side.

[0040] As shown in Fig. 2, it is preferable that a proximal opening 11b that communicates the inner cavity 11 of the first tubular portion 10 with the outside of the first tubular portion 10 is formed in the reduced diameter region 13. It is more preferable that the proximal opening 11b that communicates the inner cavity 11 of the first tubular portion 10 with the outside of the first tubular portion 10 is formed in a portion that is inclined so that the length in the radial direction y when observed from a direction perpendicular to the longitudinal direction x becomes smaller toward the proximal side. With this configuration, for example, a guide wire 4 or a second shaft 2 equipped with a medical tool can be inserted into or removed from the inner cavity 11 of the first tubular portion 10 through the proximal opening 11b.

[0041] 1 and 2, the first shaft 1 may further include a third tubular portion 70. A distal portion of the third tubular portion 70 is fixed to a proximal portion of the reduced diameter region 13, and a lumen 71 of the third tubular portion 70 and the flow path 40 can be configured to communicate with each other.

[0042] The third cylindrical portion 70 is a cylindrical portion having an inner cavity 71. It is preferable that the maximum outer diameter of the third cylindrical portion 70 is smaller than the maximum outer diameter of the first cylindrical portion 10. In addition, the minimum outer diameter of the third cylindrical portion 70 may be smaller than the minimum outer diameter of the first cylindrical portion 10.

[0043] Regarding the configuration of the third cylindrical portion 70, such as the material constituting the third cylindrical portion 70, reference can be made to the portion described for the first cylindrical portion 10. The material constituting the third cylindrical portion 70 and the material constituting the first cylindrical portion 10 may be the same or different.

[0044] The outer diameter of the third cylindrical portion 70 can be, for example, 0.60 mm or more, 0.65 mm or more, 0.70 mm or more, etc. Also, the outer diameter of the third cylindrical portion 70 can be, for example, 3.00 mm or less, 2.95 mm or less, 2.90 mm or less, etc., but is preferably 1.00 mm or less.

[0045] The inner diameter of the third cylindrical portion 70 can be, for example, 2.50 mm or less, 2.45 mm or less, 2.35 mm or less, etc. Also, the inner diameter of the third cylindrical portion 70 can be, for example, 0.30 mm or more, 0.35 mm or more, 0.40 mm or more, etc., but is preferably 0.50 mm or more.

[0046] The length from the distal end of the third cylindrical portion 70 to the proximal end of the third cylindrical portion 70 can be, for example, 100 mm or more, 150 mm or more, 200 mm or more, etc. Also, the length from the distal end of the third cylindrical portion 70 to the proximal end of the third cylindrical portion 70 can be, for example, 2400 mm or less, 2350 mm or less, 2300 mm or less, etc.

[0047] When the first shaft 1 includes the third cylindrical portion 70, the length from the distal end 10a of the first cylindrical portion 10 to the proximal end 10b of the first cylindrical portion 10 can be, for example, 30 mm or more, 35 mm or more, 40 mm or more, etc. Also, the length from the distal end 10a of the first cylindrical portion 10 to the proximal end 10b of the first cylindrical portion 10 can be, for example, 700 mm or less, 650 mm or less, 600 mm or less, etc.

[0048] It is preferable that a lubricating coating layer containing PTFE, PFA, etc. is formed on the outer surface of the third cylindrical portion 70. This makes it easier to insert the third cylindrical portion 70 into a body cavity.

[0049] The third tubular portion 70 may be provided with a position indication marker for indicating the length of the inserted portion when the first shaft 1 is inserted into a body cavity. The position indication marker may be formed, for example, by inserting the third tubular portion 70 into the inner cavity of a marker tube and welding it thereto, or may be formed by peeling off a part of the lubricant coating layer containing the above-mentioned PTFE, PFA, or the like.

[0050] The position indication markers can be provided, for example, at positions 600 mm, 900 mm, 1200 mm, etc. from the distal end of the first shaft 1.

[0051] It is preferable that the distal portion of the third tubular portion 70 and the proximal portion of the tapered region 13 are fixed so that the lumen 71 of the third tubular portion 70 and the flow path 40 communicate with each other. It is more preferable that the distal end of the third tubular portion 70 and the proximal end of the tapered region 13 are fixed so that the lumen 71 of the third tubular portion 70 and the flow path 40 communicate with each other. It is preferable that the lumen 71 of the third tubular portion 70 does not communicate with the lumen 11 of the first tubular portion 10.

[0052] 1, the catheter 100 preferably further includes a hub 72 connected to the proximal end of the first shaft 1. The hub 72 may be connected to the third cylindrical portion 70. In this case, it is preferable that the hub 72 has a port therein communicating with the inner cavity 71 of the third cylindrical portion 70, and that a fluid can be injected into the inner cavity 71 of the third cylindrical portion 70 via the port.

[0053] Although not shown, the first shaft 1 may not include the third cylindrical portion 70, and the proximal end 10b of the first cylindrical portion 10 may be directly connected to the hub 72. In this case, it is preferable that the hub 72 has a port therein communicating with the flow path 40, and that a fluid can be injected into the flow path 40 via the port.

[0054] As a material for forming the bag-shaped body portion 20, for example, the materials listed as materials for forming the first tubular portion 10 can be used. The material for forming the bag-shaped body portion 20 and the material for forming the first tubular portion 10 may be the same or different.

[0055] As shown in Figures 1 and 2, the proximal portion of the bag-shaped body portion 20 may be connected to the distal portion of the first tubular portion 10, or the proximal end of the bag-shaped body portion 20 may be connected to the distal end 10a of the first tubular portion 10.

[0056] The minimum outer diameter of the bag-like body portion 20 is preferably smaller than the outer diameter of the first cylindrical portion 10. In particular, as shown in FIG. 4, in a state where pressurization by injection of a fluid into the flow path 40 is not performed, the minimum outer diameter of the bag-like body portion 20 is preferably smaller than the outer diameter of the first cylindrical portion 10. This makes it difficult for the first shaft 1 to get caught on the wall of the body cavity when being transported to the treatment portion, and makes it easier to prevent damage to the wall of the body cavity, and also makes it easier to improve passability through the body cavity. From the viewpoint of enhancing this effect, as shown in FIG. 4, in a state where pressurization by injection of a fluid into the flow path 40 is not performed, it is more preferable that the maximum outer diameter of the bag-like body portion 20 is equal to or smaller than the outer diameter of the first cylindrical portion 10. Note that, as shown in FIG. 5 and FIG. 6, even when the bag-like body portion 20 is in a pressurized state by injection of a fluid into the flow path 40, the minimum outer diameter of the bag-like body portion 20 may be smaller than the outer diameter of the first cylindrical portion 10. As shown in Figure 18, when the expansion / contraction portion 60 is disposed in the inner cavity 25 of the bag-shaped body portion 20 and the expansion / contraction portion 60 expands in diameter, the minimum outer diameter of the bag-shaped body portion 20 may be greater than or equal to the outer diameter of the first tubular portion 10.

[0057] The bag-shaped body portion 20 provided distal to the distal end 10a of the first cylindrical portion 10 preferably has a tapered portion with an outer diameter that decreases toward the distal side. As shown in FIG. 4, in a state where pressurization by injection of a fluid into the flow path 40 is not performed, the bag-shaped body portion 20 more preferably has a tapered portion with an outer diameter that decreases toward the distal side. As shown in FIG. 4, in a state where pressurization by injection of a fluid into the flow path 40 is not performed, the entire bag-shaped body portion 20 is more preferably a tapered portion with an outer diameter that decreases toward the distal side. This makes it difficult for the first shaft 1 to get caught on the wall of the body cavity when it is transported to the treatment portion, making it easier to prevent damage to the wall of the body cavity, and also making it easier to improve passability through the body cavity. Note that, as shown in FIG. 5 and FIG. 6, in a state where the bag-shaped body portion 20 is pressurized by injection of a fluid into the flow path 40, the bag-shaped body portion 20 may have a tapered portion with an outer diameter that decreases toward the distal side. 5 and 6, when the bag-shaped body portion 20 is pressurized by injection of a fluid into the flow path 40, the bag-shaped body portion 20 may be a tapered portion whose outer diameter decreases toward the distal side. As shown in Fig. 18, when the expanding / contracting diameter portion 60 is disposed in the lumen 25 of the bag-shaped body portion 20 and the expanding / contracting diameter portion 60 expands in diameter, the bag-shaped body portion 20 may have a tapered portion whose outer diameter decreases toward the proximal side, or the bag-shaped body portion 20 may be a tapered portion whose outer diameter decreases toward the proximal side.

[0058] The bag-like body portion 20 is formed in an annular shape, but may be in the shape of a hollow truncated cone, for example, as shown in Figures 1 to 3. Although not shown, the bag-like body portion 20 may be in the shape of a hollow truncated polygonal pyramid, or may be in the shape of a combination of a hollow truncated cone and a hollow truncated polygonal pyramid, for example, a shape in which a hollow truncated cone and a hollow truncated polygonal pyramid are connected in the longitudinal direction x of the first tubular portion 10.

[0059] It is preferable that the bulging portion 30 bulges outward in the radial direction y of the first cylindrical portion 10 when the pressure is increased to a first predetermined pressure or more by the injection of fluid into the flow path 40. This allows the bulging portion 30 to bulge out when the pressure is increased to a first predetermined pressure or more. It is also preferable that the minimum inner diameter of the bag-shaped portion 20 when the pressure is increased to a second predetermined pressure or more by the injection of fluid into the flow path 40 is larger than the minimum inner diameter of the bag-shaped portion 20 when the pressure is not increased by the injection of fluid into the flow path 40. This increases the minimum inner diameter of the bag-shaped portion 20 when the pressure is increased to a second predetermined pressure or more.

[0060] The first and second predetermined pressures may be the same or different.

[0061] The bulging portion 30 may be expanded in diameter after the bulging portion 20 is expanded. The bulging portion 30 may be expanded in diameter after the bulging portion 20 is expanded. The expansion of the diameter of the bag-shaped portion 20 and the bulging of the bulging portion 30 may be performed simultaneously.

[0062] The flow path 40 for injecting fluid into the bulging portion 30 and the flow path 40 for injecting fluid into the bag-like body portion 20 may be provided separately. The flow path 40 for injecting fluid into the bulging portion 30 and the flow path 40 for injecting fluid into the bag-like body portion 20 may be connected to each other, or the flow path 40 for injecting fluid into the bulging portion 30 and the flow path 40 for injecting fluid into the bag-like body portion 20 may partially overlap each other.

[0063] The second predetermined pressure may be equal to or greater than the first predetermined pressure. In the case where the flow path 40 for injecting a fluid into the bulging portion 30 and the flow path 40 for injecting a fluid into the bag-like body portion 20 are in communication with each other, or the flow path 40 for injecting a fluid into the bulging portion 30 and the flow path 40 for injecting a fluid into the bag-like body portion 20 are partially overlapped, and the second predetermined pressure is greater than the first predetermined pressure, the bulging portion 30 can be inflated and then the bag-like body portion 20 can be enlarged in diameter. More specifically, the catheter 100 shown in FIG. 4 in a state where no fluid is injected into the flow path 40 is pressurized to a first predetermined pressure or greater by the injection of a fluid into the flow path 40, so that the bulging portion 30 inflates as shown in FIG. 5, and then the bag-like body portion 20 is pressurized to a second predetermined pressure or greater that is greater than the first predetermined pressure by the injection of a fluid into the flow path 40, so that the minimum inner diameter of the bag-like body portion 20 becomes larger as shown in FIG. 6. In the case where the flow path 40 for injecting a fluid into the bulging portion 30 and the flow path 40 for injecting a fluid into the bag-like body portion 20 are in communication with each other, or where the flow path 40 for injecting a fluid into the bulging portion 30 and the flow path 40 for injecting a fluid into the bag-like body portion 20 are partially overlapped, and the second predetermined pressure is the same as the first predetermined pressure, the expansion of the diameter of the bag-like body portion 20 and the expansion of the bulging portion 30 can be performed simultaneously. More specifically, the catheter 100 shown in FIG. 4 in a state where no fluid is injected into the flow path 40 is pressurized to a first predetermined pressure or more (above a second predetermined pressure) by the injection of a fluid into the flow path 40, so that the expansion portion 30 expands as shown in FIG. 6 and the minimum inner diameter of the bag-like body portion 20 increases at the same time. With the above-mentioned configuration, it is possible to easily suppress the movement of the first shaft 1 in the body cavity when a part of the second shaft 2 arranged in the inner cavity of the first shaft 1 is protruded from the expanded diameter bag-like body portion 20. In addition, an embodiment in which the second predetermined pressure is smaller than the first predetermined pressure is also permitted. In this case, it is preferable that a part of the second shaft 2 disposed in the inner cavity of the first shaft 1 is protruded from the bag-shaped body portion 20 after the bulging portion 30 is bulged.

[0064] As shown in Figures 2 to 6, the bag-shaped body portion 20 can be configured to have an inner surface portion 21 facing the inner cavity 25 of the bag-shaped body portion 20, and an outer surface portion 22 facing the outside of the bag-shaped body portion 20. The inner surface portion 21 has an inner surface facing the inner cavity 25, and the outer surface portion 22 has an outer surface facing the outside. The inner surface portion 21 has a distal end 21a and a proximal end 21b. The outer surface portion 22 has a distal end 22a and a proximal end 22b. It is preferable that an internal space 23 exists between the inner surface portion 21 and the outer surface portion 22.

[0065] It is preferable that the elongation percentage (%) of the length from the distal end 21a to the proximal end 21b of the inner surface portion 21 when the bag-like body portion 20 is pressurized at a second predetermined pressure or more by injecting a fluid into the flow path 40 from a state where no pressurization is performed by injecting a fluid into the flow path 40 is performed is larger than the elongation percentage (%) of the length from the distal end 22a to the proximal end 22b of the outer surface portion 22 when the bag-like body portion 20 is pressurized at a second predetermined pressure or more by injecting a fluid into the flow path 40 from a state where no pressurization is performed by injecting a fluid into the flow path 40 is performed. By being configured as described above, the inner diameter of the bag-like body portion 20 pressurized at a second predetermined pressure or more by injecting a fluid is likely to become larger than before pressurization due to the elongation of the inner surface portion 21, which is more easily stretched than the outer surface portion 22. This allows the minimum inner diameter of the bag-like body portion 20 when the bag-like body portion 20 is pressurized to a second predetermined pressure or more by injecting a fluid into the flow path 40 to be larger than the minimum inner diameter of the bag-like body portion 20 when the bag-like body portion 20 is not pressurized by injecting a fluid into the flow path 40. In the above example, the catheter 100 is easily changed from the state shown in FIG. 4 to the state shown in FIG. 6. Therefore, even when the second shaft 2 equipped with a medical tool such as a balloon, a stent, a basket, or a needle is placed in the lumen 11 of the first tubular portion 10 and transported to a treatment site, the second shaft 2 can be easily protruded from the expanded diameter portion. The elongation rate (%) is (length of each part after pressurization)÷(length of each part before pressurization).

[0066] The inner surface portion 21 and the outer surface portion 22 may be made of the same material or different materials.

[0067] When the inner surface portion 21 and the outer surface portion 22 are made of the same material, for example, it is preferable that the thickness of the inner surface portion 21 is thinner than the thickness of the outer surface portion 22. This makes the inner surface portion 21 more stretchable than the outer surface portion 22, so that the inner diameter of the bag-shaped body portion 20 is more likely to become larger than before pressurization due to the inner surface portion 21 of the bag-shaped body portion 20 stretching. In the above example, the catheter 100 is more likely to change from the state shown in FIG. 4 to the state shown in FIG. 6. This makes it easier to protrude the second shaft 2 from the expanded diameter portion even when the second shaft 2 equipped with a medical tool such as a balloon, stent, basket, or needle is placed in the lumen 11 of the first tubular portion 10 and transported to the treatment site.

[0068] When the inner surface portion 21 and the outer surface portion 22 are made of different materials, for example, it is preferable that the elongation rate of the material constituting the inner surface portion 21 is higher than that of the material constituting the outer surface portion 22. The elongation rate here refers to the elongation rate (%) when a sample made of the material constituting the inner surface portion 21 and a sample made of the material constituting the outer surface portion 22 formed in the same shape as the sample are prepared, and one end and the other end of these samples are gripped so that the gripping width is the same length and pulled with the same strength (N). As a result, the inner surface portion 21 is more easily stretched than the outer surface portion 22, and the inner diameter of the bag-like body portion 20 is easily made larger than before pressure is applied by the elongation of the inner surface portion 21 of the bag-like body portion 20. In the above example, the catheter 100 is easily changed from the state shown in FIG. 4 to the state shown in FIG. 6. As a result, even when the second shaft 2 equipped with a medical tool such as a balloon, stent, basket, or needle is placed in the lumen 11 of the first tubular portion 10 and transported to a treatment site, it is possible to easily protrude the second shaft 2 from the expanded diameter portion.

[0069] In a cross section parallel to the longitudinal direction x of the first tubular portion 10, the angle δ between the inner surface portion 21 and the outer surface portion 22 in a state where no pressure is applied by injecting a fluid into the flow path 40 is preferably an acute angle as shown in FIG. 4. The angle δ may be 85° or less, 80° or less, or 70° or less. The angle δ may be 1° or more, 3° or more, or 5° or more. This configuration makes it easier to reduce the outer diameter of the distal end portion of the bag-like body portion 20. Therefore, the first shaft 1 is less likely to get caught on the wall of the body cavity when being transported to the treatment portion, and it is easier to prevent damage to the wall of the body cavity, and it is easier to improve passability through the body cavity.

[0070] In a cross section parallel to the longitudinal direction x of the first tubular portion 10, the angle ε between the inner surface portion 21 and the outer surface portion 22 when the first tubular portion 10 is pressurized to a first predetermined pressure or higher by injection of a fluid into the flow path 40 is preferably an acute angle, as shown in Fig. 5. The angle ε may be 85° or less, 80° or less, or 70° or less. The angle ε may be 1° or more, 3° or more, or 5° or more.

[0071] In a cross section parallel to the longitudinal direction x of the first tubular portion 10, the angle ζ between the inner surface portion 21 and the outer surface portion 22 when the first tubular portion 10 is pressurized to a second predetermined pressure or more by the injection of a fluid into the flow path 40 is preferably an acute angle as shown in FIG. 6. The angle ζ may be 85° or less, 80° or less, or 70° or less. The angle ζ may be 1° or more, 3° or more, or 5° or more. This configuration makes it easier to reduce the thickness of the distal end portion of the bag-like body portion 20. In other words, it makes it easier to shorten the length between the inner surface of the inner surface portion 21 and the outer surface of the outer surface portion 22. Therefore, it makes it easier to increase the inner diameter of the distal end portion of the bag-like body portion 20 when the bag-like body portion 20 is pressurized to a second predetermined pressure or more by the inflow of a fluid into the flow path 40. Therefore, even in the case where the second shaft 2 equipped with a medical device such as a balloon, stent, basket, needle, etc. is placed in the inner cavity 11 of the first tubular portion 10 and transported to the treatment site, it is possible to easily protrude the second shaft 2 from the expanded portion.

[0072] As shown in Figs. 2 and 3, the internal space 23 is a space formed within the wall that constitutes the annular bag-shaped body portion 20. In the example shown in Figs. 2 and 3, the internal space 23 is a space that exists within the wall that forms the inner cavity 25 of the bag-shaped body portion 20. As shown in Figs. 2 and 3, the internal space 23 preferably exists throughout the entire circumferential direction within the wall of the bag-shaped body portion 20. In other words, the internal space 23 is preferably a space that communicates in the circumferential direction within the wall of the bag-shaped body portion 20. Although not shown, the internal space 23 may exist only in a portion of the circumferential direction within the wall of the bag-shaped body portion 20.

[0073] It is preferable that the internal space 23 does not communicate with the inner cavity 11 of the first tubular portion 10. It is also preferable that the internal space 23 does not communicate with the inner cavity 25 of the bag-shaped body portion 20. This makes it easier for the fluid injected into the flow path 40 to efficiently flow into the internal space 23 formed in the bag-shaped body portion 20.

[0074] As shown in Fig. 4, in a cross section passing through the central axis of the first tubular portion 10 and along the longitudinal direction x of the first tubular portion 10 in a state where pressurization by injection of a fluid into the flow path 40 is not performed, it is preferable that the length of the internal space 23 of the bag-like body portion 20 in the radial direction y of the first tubular portion 10 becomes shorter from the proximal end to the distal end of the internal space 23 of the bag-like body portion 20. This makes it easier to reduce the outer diameter at the distal end of the bag-like body portion 20. Therefore, when the first shaft 1 is transported to the treatment portion, it is less likely to get caught on the wall of the body cavity, and it is easier to prevent damage to the wall of the body cavity, and it is easier to improve passability through the body cavity.

[0075] As shown in Fig. 6, in a cross section passing through the central axis of the first tubular portion 10 and taken along the longitudinal direction x of the first tubular portion 10 when the bag-like body portion 20 is pressurized to a second predetermined pressure or higher by the injection of a fluid into the flow path 40, it is preferable that the length of the internal space 23 of the bag-like body portion 20 in the radial direction y of the first tubular portion 10 becomes shorter from the proximal end to the distal end of the internal space 23 of the bag-like body portion 20. This makes it easier to reduce the outer diameter of the distal end of the bag-like body portion 20. Therefore, when the minimum inner diameter of the bag-like body portion 20 becomes larger by pressurizing the bag-like body portion 20 to a second predetermined pressure or higher, it is easier to prevent the bag-like body portion 20 from unintentionally contacting the wall of the body cavity.

[0076] 4, in a cross section passing through the central axis of the first tubular portion 10 and taken along the longitudinal direction x of the first tubular portion 10 in a state in which pressurization by injection of a fluid into the flow path 40 is not performed, the length of the internal space 23 of the bag-like body portion 20 in the radial direction y of the first tubular portion 10 is preferably equal to or less than the length of the flow path 40 in the radial direction y of the first tubular portion 10. This makes it easier to reduce the outer diameter of the bag-like body portion 20. Therefore, when the first shaft 1 is transported to the treatment portion, it is less likely to get caught on the wall of the body cavity, and it is easier to prevent damage to the wall of the body cavity, and it is easier to improve passability through the body cavity.

[0077] As shown in Fig. 6, in a cross section passing through the central axis of the first tubular portion 10 and taken along the longitudinal direction x of the first tubular portion 10 when the bag-shaped portion 20 is pressurized to a second predetermined pressure or more by the injection of a fluid into the flow path 40, the length of the internal space 23 of the bag-shaped portion 20 in the radial direction y of the first tubular portion 10 is preferably equal to or less than the length of the flow path 40 in the radial direction y of the first tubular portion 10. This makes it easier to reduce the outer diameter of the bag-shaped portion 20. Therefore, when the minimum inner diameter of the bag-shaped portion 20 becomes larger by pressurizing the bag-shaped portion 20 to a second predetermined pressure or more, it is easier to prevent the bag-shaped portion 20 from unintentionally contacting the wall of the body cavity.

[0078] The length of the bag-like body portion 20 in the longitudinal direction x of the first tubular portion 10 when no pressurization is performed by injecting a fluid into the flow path 40, and the length of the bag-like body portion 20 in the longitudinal direction x of the first tubular portion 10 when the bag-like body portion 20 is pressurized to a second predetermined pressure or higher by injecting a fluid into the flow path 40, may be the same or different.

[0079] The length of the bag-like body portion 20 in the longitudinal direction x of the first cylindrical portion 10 in a state in which pressurization by injection of a fluid into the flow path 40 is not performed can be, for example, 1 mm or more, 3 mm or more, 5 mm or more, etc. The length of the bag-like body portion 20 in the longitudinal direction x of the first cylindrical portion 10 in a state in which pressurization by injection of a fluid into the flow path 40 is not performed can be, for example, 20 mm or less, 18 mm or less, 15 mm or less, etc.

[0080] The length of the bag-like body portion 20 in the longitudinal direction x of the first cylindrical portion 10 when the fluid is injected into the flow path 40 and the bag-like body portion 20 is pressurized to the second predetermined pressure or higher can be, for example, 1 mm or more, 3 mm or more, 5 mm or more, etc. The length of the bag-like body portion 20 in the longitudinal direction x of the first cylindrical portion 10 when the fluid is injected into the flow path 40 and the bag-like body portion 20 is pressurized to the second predetermined pressure or higher can be, for example, 20 mm or less, 18 mm or less, 15 mm or less, etc.

[0081] The minimum inner diameter of the bag-like body portion 20 in a state where pressurization by injection of a fluid into the flow path 40 is not performed is preferably a size that allows the guide wire 4 to be inserted. The minimum inner diameter of the bag-like body portion 20 in a state where pressurization by injection of a fluid into the flow path 40 is not performed may be 30% or more, 35% or more, or 40% or more of the inner diameter of the first cylindrical portion 10. The minimum inner diameter of the bag-like body portion 20 in a state where pressurization by injection of a fluid into the flow path 40 is not performed may be 70% or less, 65% or less, or 60% or less of the inner diameter of the first cylindrical portion 10. The minimum inner diameter of the bag-like body portion 20 in a state where pressurization by injection of a fluid into the flow path 40 is not performed may be, for example, 0.30 mm or more, 0.35 mm or more, 0.40 mm or more, etc. Also, the minimum inner diameter of the bag-like body portion 20 in a state where pressurization by injection of a fluid into the flow path 40 is not performed may be, for example, 2.00 mm or less, 1.95 mm or less, 1.90 mm or less, etc.

[0082] As shown in Fig. 4, in a state where pressurization by injection of a fluid into the flow path 40 is not performed, it is preferable that the inner diameter of the bag-like body portion 20 is smallest at the distal end of the bag-like body portion 20. As shown in Fig. 5, in a state where pressurization to a first predetermined pressure or more is performed by injection of a fluid into the flow path 40, it is preferable that the inner diameter of the bag-like body portion 20 is smallest at the distal end of the bag-like body portion 20. In a state where pressurization to a second predetermined pressure or more is performed by injection of a fluid into the flow path 40, it may be the proximal end of the bag-like body portion 20 or the distal end of the bag-like body portion 20 that has the smallest inner diameter.

[0083] The minimum outer diameter of the bag-shaped portion 20 in a state where pressurization by injection of a fluid into the flow path 40 is not performed can be, for example, 0.31 mm or more, 0.36 mm or more, 0.41 mm or more, etc. Also, the minimum outer diameter of the bag-shaped portion 20 in a state where pressurization by injection of a fluid into the flow path 40 is not performed can be, for example, 3.00 mm or less, 2.90 mm or less, 2.80 mm or less, etc.

[0084] As shown in Fig. 4, in a state where pressurization by injection of a fluid into the flow path 40 is not performed, it is preferable that the distal end of the bag-like body portion 20 has the smallest outer diameter. As shown in Fig. 5, in a state where pressurization to a first predetermined pressure or more is performed by injection of a fluid into the flow path 40, it is preferable that the distal end of the bag-like body portion 20 has the smallest outer diameter. As shown in Fig. 6, in a state where pressurization to a second predetermined pressure or more is performed by injection of a fluid into the flow path 40, it is preferable that the distal end of the bag-like body portion 20 has the smallest outer diameter.

[0085] The material constituting the bulging portion 30 may be any of the materials listed as the materials constituting the first tubular portion 10 and the materials listed as the materials constituting the balloon described below. The material constituting the bulging portion 30 and the material constituting the first tubular portion 10 may be the same or different.

[0086] As shown in Figs. 6 to 9, the bulging portion 30 may be a portion that bulges outward in the radial direction y of the first tubular portion 10 by a part of the first tubular portion 10 expanding. Although not shown, the bulging portion 30 may have a structure different from that of the first tubular portion 10. For example, the bulging portion 30 may be a bag-shaped member disposed outside the first tubular portion 10, and a fluid may be injected through a tubular member connected to the bag-shaped member. In this case, the inner cavity of the tubular member functions as the flow path 40.

[0087] As shown in Figures 5 and 6, when the bulging portion 30 is a portion that bulges outward in the radial direction y of the first tubular portion 10 by a part of the first tubular portion 10 expanding, it is preferable that the portion of the first tubular portion 10 that constitutes the bulging portion 30 is thinner than the portion of the first tubular portion 10 other than the bulging portion 30. This makes it easier for the portion of the first tubular portion 10 that constitutes the bulging portion 30 to stretch than the portion of the first tubular portion 10 other than the bulging portion 30, so that the portion of the first tubular portion 10 that constitutes the bulging portion 30 can be easily bulged. In the above example, the catheter 100 is more likely to change from the state shown in Figure 4 to the state shown in Figures 5 and 6.

[0088] As shown in Figs. 5 and 6, when the bulging portion 30 is a portion bulging outward in the radial direction y of the first tubular portion 10 by a part of the first tubular portion 10 expanding, it is preferable that the elongation rate of the material constituting the bulging portion 30 of the first tubular portion 10 is higher than the elongation rate of the material constituting the other parts of the first tubular portion 10 than the bulging portion 30. The elongation rate here refers to the elongation rate (%) when a sample made of the material constituting the bulging portion 30 of the first tubular portion 10 and a sample made of the material constituting the other parts of the first tubular portion 10 than the bulging portion 30 formed in the same shape as the sample are prepared, and one end and the other end of these samples are held so that the widths are the same length and pulled with the same strength (N). This makes the bulging portion 30 more easily stretchable than the other parts of the bulging portion 30, so that the bulging portion 30 is more easily bulged by pressure. In the above example, the catheter 100 is more likely to change from the state shown in Fig. 4 to the state shown in Figs. 5 and 6.

[0089] The bulge portion 30 may be present in a portion of the circumferential direction of the first tubular portion 10 as shown in Figures 7 and 8, or may be present in the entire circumferential direction of the first tubular portion 10 as shown in Figure 9.

[0090] The first shaft 1 may have only one bulging portion 30, or may have a plurality of bulging portions 30.

[0091] 7 to 9, the swelling height 30L of the swelling portion 30 in the radial direction y of the first cylindrical portion 10 may vary in the circumferential direction of the first cylindrical portion 10. The swelling height 30L of the swelling portion 30 refers to the length of the portion swelling in the radial direction y of the first cylindrical portion 10. Although not shown, the swelling height 30L of the swelling portion 30 in the radial direction y of the first cylindrical portion 10 may be constant and not vary in the circumferential direction of the first cylindrical portion 10.

[0092] The frictional force of the outer surface of the bulging portion 30 is preferably higher than that of the outer surface 10d of the first cylindrical portion 10. The frictional force of the outer surface of the bulging portion 30 when it is pressurized by injecting a fluid into the flow path 40 is more preferably higher than that of the outer surface 10d of the first cylindrical portion 10 when it is pressurized by injecting a fluid into the flow path 40. The frictional force of each surface can be adjusted by coating, surface roughness, changing the material, etc. With the above configuration, it is possible to easily suppress the movement of the first shaft 1 in the body cavity. Note that, as shown in FIG. 5, when the bulging portion 30 is a portion that bulges outward in the radial direction y of the first cylindrical portion 10 by a part of the first cylindrical portion 10 expanding, the frictional force of the outer surface of the bulging portion 30 is preferably higher than that of the outer surface 10d of the first cylindrical portion 10 that constitutes the part of the first cylindrical portion 10 other than the bulging portion 30. It is more preferable that the frictional force of the outer surface of the bulge portion 30 when it is pressurized by injecting a fluid into the flow path 40 is higher than the frictional force of the outer surface 10d of the first tubular portion 10 that constitutes the first tubular portion 10 other than the bulge portion 30 when it is pressurized by injecting a fluid into the flow path 40.

[0093] 5 and 6, the bulging portion 30 is preferably located proximal to the proximal end of the bag-shaped body portion 20. The bulging portion 30 may also be located proximal to the distal end 10a of the first tubular portion 10. The bulging portion 30 is preferably provided in the distal portion of the first tubular portion 10.

[0094] 4 and 10 to 12, the first tubular portion 10 has a wall 12 that forms a lumen 11, and the flow path 40 can be configured to be formed within the wall 12 of the first tubular portion 10. With this configuration, it is not necessary to provide a separate member for forming the flow path 40, and therefore the catheter 100 can be made thinner.

[0095] 4 and 10, the first tubular portion 10 may have a first outer cylinder 15 and a first inner cylinder 14 disposed in the lumen of the first outer cylinder 15, and the flow path 40 may be a space defined by an inner surface 15c of the first outer cylinder 15 and an outer surface 14d of the first inner cylinder 14. With this configuration, it is not necessary to provide a separate member for forming the flow path 40, and therefore the catheter 100 can be easily made thinner.

[0096] The thickness of the first outer cylinder 15 can be 0.010 mm or more, 0.015 mm or more, 0.020 mm or more, etc. Also, the thickness of the first outer cylinder 15 can be 0.500 mm or less, 0.450 mm or less, 0.400 mm or less, etc.

[0097] The thickness of the first inner cylinder 14 can be 0.010 mm or more, 0.015 mm or more, 0.020 mm or more, etc. Also, the thickness of the first inner cylinder 14 can be 0.500 mm or less, 0.450 mm or less, 0.400 mm or less, etc.

[0098] 10, the distance between the inner surface 15c of the first outer cylinder 15 and the outer surface 14d of the first inner cylinder 14 is preferably 0.01 mm or more and 1.0 mm or less. This makes it possible to reduce pressure loss when delivering the fluid to the distal end through the flow channel 40.

[0099] The first outer cylinder 15 may have a distal end and a proximal end, and may have a lumen extending in the longitudinal direction x. The same is true for the first inner cylinder 14.

[0100] When the bag-like body portion 20 is changed from a state where it is not pressurized by injecting a fluid into the flow path 40 to a state where it is pressurized by injecting a fluid into the flow path 40 at a second predetermined pressure or more, the elongation percentage (%) of the length from the distal end 21a to the proximal end 21b of the inner surface portion 21 is preferably larger than the elongation percentage (%) of the length from the distal end 10a to the proximal end 10b of the first cylindrical portion 10. In particular, the above configuration is preferable when the flow path 40 is formed within the wall 12 of the first cylindrical portion 10. Since the elongation percentage (%) of the bag-like body portion 20 is higher than that of the first cylindrical portion 10, the first cylindrical portion 10 can be made less likely to deform due to the pressure of the fluid, and therefore the fluid injected into the flow path 40 can be easily supplied to the bag-like body portion 20 in a stable manner.

[0101] 11 and 12, the flow path 40 may extend linearly in the longitudinal direction x of the first cylindrical portion 10 within the wall 12 of the first cylindrical portion 10. Although not shown, the flow path 40 may be formed in a corrugated shape within the wall 12 of the first cylindrical portion 10, or the flow path 40 may be formed in a spiral shape that circles around the inner cavity 11 of the first cylindrical portion 10 within the wall 12 of the first cylindrical portion 10.

[0102] 11 and 12 , when the flow path 40 extends linearly in the longitudinal direction x within the wall 12 of the first cylindrical portion 10, it is preferable that the internal space 23 that is continuous throughout the entire circumferential direction of the first cylindrical portion 10 within the wall of the bag-shaped body portion 20 communicates with the linear flow path 40. This allows the fluid injected into the flow path 40 to be injected into the internal space 23 of the bag-shaped body portion 20.

[0103] The flow path 40 can be formed not only in the wall 12 of the first cylindrical portion 10, but also by providing a structure other than the first cylindrical portion 10. For example, as shown in Figs. 13 and 14, the flow path 40 may be formed by a fourth cylindrical portion 41 disposed in the lumen 11 of the first cylindrical portion 10. The fourth cylindrical portion 41 is a cylindrical portion having a lumen, and the lumen of the fourth cylindrical portion 41 is the flow path 40. By disposing the fourth cylindrical portion 41 in the lumen 11 of the first cylindrical portion 10, the catheter 100 becomes easily narrower. Although not shown, the fourth cylindrical portion 41 may be disposed outside the first cylindrical portion 10.

[0104] When the flow path 40 is formed by the fourth cylindrical portion 41, it is preferable that the distal end portions of the bag-shaped body portion 20 and the fourth cylindrical portion 41 are fixed as shown in Figures 13 and 14. It is also preferable that the bag-shaped body portion 20 has a hole 24 that communicates the flow path 40 with the internal space 23. This allows the fluid injected into the flow path 40 formed by the fourth cylindrical portion 41 to be injected into the internal space 23 of the bag-shaped body portion 20.

[0105] Regarding the configuration of the fourth cylindrical portion 41, such as the material constituting the fourth cylindrical portion 41, reference can be made to the portion described for the first cylindrical portion 10. The material constituting the first cylindrical portion 10, the material constituting the third cylindrical portion 70, and the material constituting the fourth cylindrical portion 41 may be the same or different.

[0106] The flow path 40 for injecting fluid into the bulging portion 30 may be connected to the flow path 40 for injecting fluid into the bag-shaped body portion 20. In addition, a part of the flow path 40 for injecting fluid into the bulging portion 30 and a part of the flow path for injecting fluid into the bag-shaped body portion 20 may overlap.

[0107] The fluid to be introduced into the flow channel 40 is not particularly limited, but may be, for example, a liquid such as physiological saline, a contrast medium, or a mixture thereof, or a gas such as air, nitrogen, or carbon dioxide.

[0108] The fluid injected up to the bag-shaped body portion 20 may pass through a flow path 40 capable of injecting the fluid up to the bulging portion 30. The fluid injected up to the bulging portion 30 may pass through a flow path 40 capable of injecting the fluid up to the bag-shaped body portion 20.

[0109] 15 and 16, a reinforcing member 16 may be disposed between the flow path 40 and the inner cavity 11 of the first tubular portion 10. This makes it possible to easily prevent the flow path 40 from collapsing even when a diameter-expanding member is disposed in the inner cavity of the first shaft 1.

[0110] The reinforcing member 16 can be made of metal or resin. As the metal or resin constituting the reinforcing member 16, the materials mentioned as the materials constituting the first tubular portion 10 can be used.

[0111] The reinforcing member 16 is preferably configured by a tube, a braid in which wire is woven, a coil in which wire is wound, or a combination of these. The wire may be a solid wire or a stranded wire.

[0112] 19, in a state in which pressurization by injection of a fluid into the flow path 40 is not performed, the first tubular portion 10 may have a protruding portion 17 that protrudes inward in the radial direction y of the first tubular portion 10. In other words, the protruding portion 17 is a portion that protrudes inward in the radial direction y of the first tubular portion 10 regardless of whether or not a fluid is injected into the flow path 40. This makes it possible to easily suppress movement of a member disposed in the inner cavity of the first shaft 1 in the longitudinal direction x of the first tubular portion 10.

[0113] The protruding height 17L of the protruding portion 17 and the protruding height 30L of the bulging portion 30 may be the same or different. The protruding height 17L of the protruding portion 17 may be higher than the protruding height 30L of the bulging portion 30. The protruding height 17L of the protruding portion 17 may be lower than the protruding height 30L of the bulging portion 30. The protruding height 17L of the protruding portion 17 refers to the length of the protruding portion in the radial direction y of the first cylindrical portion 10. The protruding height 30L of the bulging portion 30 refers to the length of the bulging portion in the radial direction y of the first cylindrical portion 10.

[0114] A radiopaque portion 3 may be provided in at least one of the bag-shaped body portion 20 and the region from the distal end 10a of the first tubular portion 10 to a position 10 cm proximal to the bag-shaped body portion 20. This configuration makes it possible to visually confirm the position of the distal end of the catheter 100 by using an X-ray imaging device. Figs. 13 and 14 show an embodiment in which the radiopaque portion 3 is provided in the first tubular portion 10. Figs. 15, 17, and 18 show an embodiment in which the radiopaque portion 3 is provided in the bag-shaped body portion 20.

[0115] The radiopaque portion 3 may be provided only in the bag-shaped body portion 20. The radiopaque portion 3 may be provided only in a region from the distal end 10a of the first tubular portion 10 to a position 10 cm proximal to the bag-shaped body portion 20. The radiopaque portion 3 may be provided in both the bag-shaped body portion 20 and a region from the distal end 10a of the first tubular portion 10 to a position 10 cm proximal to the bag-shaped body portion 20.

[0116] 15, 17, and 18, it is preferable that a radiopaque portion 3 is provided at the distal end of the bag-shaped body portion 20. This makes it easier to visually confirm the proximal end of the diameter-expanding portion 60 that contacts the treatment portion described below.

[0117] The shape of the radiopaque portion 3 is preferably tubular, and examples of such shapes include a cylindrical shape, a polygonal cylindrical shape, a cylindrical shape with a cut to form a C-shaped cross section, and a coil shape formed by winding a wire.

[0118] The material constituting the above-mentioned X-ray opaque portion 3 may be, for example, an X-ray opaque substance such as lead, barium, iodine, tungsten, gold, platinum, iridium, stainless steel, titanium, or a cobalt-chromium alloy, and X-ray opaque particles such as barium sulfate may be dispersed in the first tubular portion 10, the bag-shaped portion 20, or a separately provided resin member.

[0119] 15 to 18, the catheter 100 may further include a second shaft 2 disposed in the lumen 11 of the first tubular portion 10. As shown in Figs. 15 to 18, the second shaft 2 may include a second tubular portion 50.

[0120] 15 and 16, the second shaft 2 is preferably disposed in the inner cavity of the first shaft 1 in a state where it can move relative to the first shaft 1. The inner cavity of the first shaft 1 is preferably composed of the inner cavity 11 of the first tubular portion 10 and the inner cavity 25 of the bag-shaped portion 20.

[0121] The second tubular portion 2 can be configured to have an inner cavity extending in the longitudinal direction x. The inner cavity of the second tubular portion 50 can be used as an insertion path for a guide wire 4 or the like, as shown in Figs. 15 to 18.

[0122] As shown in Figures 15 to 18, the second tubular portion 50 may be configured to include a second outer tube 52 arranged in the inner cavity 11 of the first tubular portion 10, and a second inner tube 51 arranged in the inner cavity of the second outer tube 52.

[0123] Regarding the configuration of the second cylindrical portion 50, such as the material constituting the second cylindrical portion 50, the portions described for the first cylindrical portion 10 can be referred to. The material constituting the first cylindrical portion 10, the material constituting the third cylindrical portion 70, the material constituting the fourth cylindrical portion 41, and the material constituting the second cylindrical portion 50 may be the same or different. Note that the material constituting the second inner cylinder 51 and the material constituting the second outer cylinder 52 may be the same or different.

[0124] The inner surface of the second inner tube 51 preferably has a portion made of a fluororesin or a polyolefin resin. Only a portion of the inner surface of the second inner tube 51 may be made of a fluororesin or a polyolefin resin, or the entire inner surface of the second inner tube 51 may be made of a fluororesin or a polyolefin resin. This allows the second inner tube 51 to slide easily over the guidewire 4, making it easier to improve the operability of the catheter 100.

[0125] A control mechanism that suppresses movement of the second shaft 2 in the longitudinal direction x of the first tubular portion 10 may be provided in the proximal portion of the catheter 100. With this configuration, the catheter 100 can be transported to the treatment site while the control mechanism suppresses movement of the second shaft 2 in the longitudinal direction x of the first tubular portion 10, making it easier to transport the catheter 100 to the treatment site.

[0126] Although not shown, an example of the control mechanism is a gripping member that is provided on the third tubular portion 70 and can grip the second tubular portion 50. By gripping the second tubular portion 50 with the gripping member, it is possible to temporarily suppress movement of the second tubular portion 50 in the longitudinal direction x of the first tubular portion 10. Then, by removing the second tubular portion 50 from the gripping member, it is possible to return the second tubular portion 50 to a state in which it is movable relative to the first shaft 1. Examples of the gripping member include a rubber member provided with a slit that grips the second tubular portion 50 in a pinched manner, a clip made of a rigid resin, and the like.

[0127] The second shaft 2 preferably includes a medical device such as a balloon, a stent, a basket, a needle, etc. In particular, it is more preferable that the second shaft 2 includes a diameter expanding / contracting section 60 fixed to the distal part of the second tubular section 50, as shown in Figs.

[0128] As the expandable / contractable portion 60, for example, a balloon or a stent that can expand and contract in diameter can be used.

[0129] The balloon is preferably made of a resin. Examples of the resin constituting the balloon include polyamide resin, polyester resin, polyurethane resin, polyolefin resin, vinyl chloride resin, silicone resin, and natural rubber. These may be used alone or in combination of two or more. Among them, polyamide resin, polyester resin, and polyurethane resin are preferably used. Elastomer resin can be used from the viewpoint of thinning and flexibility of the balloon.

[0130] When the second tubular portion 50 has a second inner cylinder 51 and a second outer cylinder 52, and the expanding / contracting portion 60 is a balloon, it is preferable that the distal end of the expanding / contracting portion 60 is fixed to the distal portion of the second inner cylinder 51, and the proximal end of the expanding / contracting portion 60 is fixed to the distal portion of the second outer cylinder 52, as shown in Figures 15, 17, and 18. The expanding / contracting portion 60 can be expanded by injecting a fluid into the space surrounded by the second inner cylinder 51 and the second outer cylinder 52.

[0131] A stent is a cylindrical structure that can expand and contract in diameter and is composed of a mesh structure such as a mesh. It is preferable that the stent expands and contracts in, for example, its circumferential direction and axial direction. Examples of stents include a coil-shaped stent made of a single linear metal or polymer material, a metal tube or a tube made of a polymer material cut out with a laser or the like, a stent assembled by welding linear members, a stent made by weaving multiple linear metals, and the like.

[0132] The stent is preferably made of a shape-memory alloy or a 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, or the like.

[0133] The stent may be a self-expanding stent or a balloon-expandable stent.

[0134] As the diameter expanding / contracting section 60, it is preferable to use a balloon or a stent having a coating layer formed on the outer surface 63. After the catheter 100 reaches the treatment site, fluid is injected into the flow path 40 to pressurize the bag-shaped body section 20, and the minimum inner diameter of the bag-shaped body section 20 becomes larger than before pressurization. In the above example, the catheter 100 changes from the state shown in FIG. 15 to the state shown in FIG. 17 by injecting fluid. After the balloon or stent placed in the lumen of the first shaft 1 in the state shown in FIG. 15 is transported to the treatment site, the minimum lumen of the bag-shaped body section 20 is enlarged as shown in FIG. 17. This makes it easier to protrude a part of the second shaft 2 equipped with the balloon or stent from the first shaft 1. This makes it easier to suppress peeling of the coating layer provided on the outer surface 63 of the balloon or stent when the balloon or stent is placed in the treatment site.

[0135] 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 only on a part of the outer surface of the balloon or stent, or may be formed on the entire outer surface of the balloon or stent.

[0136] For example, the coating layer may include a lubricious coating agent or a bioactive agent.

[0137] Examples of lubricating coating agents include silicone-based coating agents such as silicone and polydimethylsiloxane; acrylic 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.

[0138] Examples of the physiologically active agent include paclitaxel, docetaxel, sirolimus, temsirolimus, everolimus, zotarolimus, biolimus A9, cilostazol, cyclosporine, and NF-κB decoy oligo. The physiologically active agent may be used alone, or a combination of multiple physiologically active agents may be used. The balloon or stent may be coated with only the physiologically active agent, or may be coated with the physiologically active agent with an appropriate additive.

[0139] 18, after a part of the second shaft 2 is protruded from the first shaft 1, a first portion 61 which is a part of the expandable / contractable portion 60 is located in the inner cavity of the first shaft 1, a second portion 62 which is a portion of the expandable / contractable portion 60 located distal to the first portion 61 is located outside the first shaft 1, the maximum outer diameter of the second portion 62 is larger than the maximum outer diameter of the first tubular portion 10, and the outer surface of the first portion 61 is preferably inscribed in the first shaft 1. This makes it easier to adjust the length of the expandable / contractable portion 60 which contacts the treatment portion to a desired length.

[0140] The length of the catheter 100 from the distal end to the proximal end can be, for example, 200 mm or more, 250 mm or more, 300 mm or more, etc. Also, the length of the catheter 100 from the distal end to the proximal end can be, for example, 2500 mm or less, 2450 mm or less, 2400 mm or less, etc.

[0141] Although not shown, the proximal end of the catheter 100 is provided with the hub 72, a controller used to operate the catheter 100, other devices, etc., and may further have a mechanism capable of fixing the relative positions of these members so that they do not move. The mechanism is preferably capable of fixing the relative positions of at least two of the hub 72, the controller, and the other devices so that they do not move. Here, being capable of being fixed means that it is possible to fix the relative positions of the at least two members so that they do not move, and that it is also possible to release the fixed state so that the relative positions of the at least two members can be moved. [Explanation of symbols]

[0142] 1: First shaft 2: Second shaft 3: Radiopaque area 4: Guidewire 10: First cylindrical section 10a: Distal end 10b: Proximal end 10c: Inner surface 10d: Outer surface 11:Lumen 11a: Distal opening 11b: Proximal opening 12: Wall 13:Reduced diameter area 14: First inner cylinder 14d: Outer surface 15: First outer cylinder 15c: Inner surface 16: Reinforcement member 17:Protrusion 17L: Projection height 20: Bag-like body part 21: Inner surface 21a: Distal end 21b: Proximal end 22: External part 22a: Distal end 22b: Proximal end 23:Interior space 24: Hole 25: lumen 30:bulge 30L: Bulging height 40: Flow path 41: Fourth cylindrical section 50: Second cylindrical section 51: Second inner cylinder 52: Second outer cylinder 60: Expanding / contracting section 61: Part 1 62:Second part 63:Outer surface 70: Third cylindrical section 71: lumen 72: Hub 100: Catheter x: longitudinal direction of the first cylindrical portion y: radial direction of the first cylindrical portion

Claims

1. A first tubular portion having a longitudinal direction and an inner cavity extending in the longitudinal direction; A bag-shaped portion located distal to the first cylindrical portion and formed in an annular shape; a bulging portion that bulges outward in a radial direction of the first cylindrical portion; a flow path through which a fluid can be injected to the bag-shaped body portion and the bulging portion; A catheter having a first shaft comprising: a minimum inner diameter of the bag-shaped body portion when the bag-shaped body portion is pressurized by injection of a fluid into the flow path is larger than a minimum inner diameter of the bag-shaped body portion when the bag-shaped body portion is not pressurized by injection of a fluid into the flow path; The catheter has a bulging portion that bulges outward in the radial direction of the first cylindrical portion when pressurized by injection of fluid into the flow path.

2. the bulging portion bulges outward in a radial direction of the first cylindrical portion when the fluid is injected into the flow path and the pressure therein is increased to a first predetermined pressure or higher; 2. The catheter according to claim 1, wherein the minimum inner diameter of the bag-shaped body portion when the bag-shaped body portion is pressurized to a second predetermined pressure or higher by injecting a fluid into the flow path is larger than the minimum inner diameter of the bag-shaped body portion when it is not pressurized by injecting a fluid into the flow path.

3. 3. The catheter of claim 2, wherein the second predetermined pressure is greater than or equal to the first predetermined pressure.

4. 4. The catheter according to claim 1, wherein the fluid injected into the bag-shaped body portion passes through a flow path that allows the fluid to be injected into the bulging portion.

5. The catheter according to any one of claims 1 to 3, wherein a minimum outer diameter of the bag-shaped portion is smaller than an outer diameter of the first tubular portion.

6. The bag portion has an inner surface facing the inner cavity of the bag portion and an outer surface facing the exterior of the bag portion, The catheter according to any one of claims 1 to 3, wherein in a cross section parallel to the longitudinal direction, the angle between the inner surface and the outer surface is an acute angle when no pressure is applied by injecting a fluid into the flow path.

7. The catheter according to any one of claims 1 to 3, wherein the bag-shaped body portion has a tapered portion whose outer diameter decreases toward the distal side.

8. The catheter according to any one of claims 1 to 3, wherein a bulging height of the bulging portion in a radial direction of the first tubular portion varies in a circumferential direction of the first tubular portion.

9. The catheter according to any one of claims 1 to 3, wherein the frictional force of the outer surface of the bulging portion is higher than the frictional force of the outer surface of the first tubular portion.

10. The catheter according to any one of claims 1 to 3, wherein the bulge portion is located proximal to the proximal end of the bag-shaped portion.

11. The bag-shaped body portion has an internal space, 4. A catheter as described in claim 2 or 3, wherein when the bag-shaped body portion is pressurized to a pressure equal to or greater than the second predetermined pressure by injection of fluid into the flow path, in a cross section passing through the central axis of the first tubular portion and along the longitudinal direction, the length of the internal space of the bag-shaped body portion in the radial direction of the first tubular portion becomes shorter from the proximal end to the distal end of the internal space of the bag-shaped body portion.

12. The bag-shaped body portion has an internal space, 4. A catheter as described in claim 2 or 3, wherein in a cross section passing through the central axis of the first tubular portion and along the longitudinal direction when the bag-shaped body portion is pressurized to a pressure equal to or greater than the second predetermined pressure by injection of fluid into the flow path, the length of the internal space of the bag-shaped body portion in the radial direction of the first tubular portion is less than the length of the flow path in the radial direction of the first tubular portion.

13. a second shaft disposed in the inner cavity of the first tubular portion; The catheter according to any one of claims 1 to 3, wherein the second shaft comprises a second tubular portion and a diameter expanding / contracting portion fixed to a distal portion of the second tubular portion.

Images