catheter

Abstract

Provided is a catheter (1) having a tubular body (2), wherein: the tubular body (2) comprises a base section (23) and a shaping section (24); the shaping section (24) comprises a first bending section (25), a first middle section (26) that is further to the tip-end side than the first bending section (25), a second bending section (27) that is further to the tip-end side than the first middle section (26), a second middle section (28) that is further to the tip-end side than the second bending section (27), a third bending section (29) that is further to the tip-end side than the second middle section (28), and a distal-end section (30) that is further to the tip-end side than the third bending section (29); the first bending section (25) and the first middle section (26) are located on a first plane (P1); the second bending section (27) and the second middle section (28) are located on a second plane (P2) different from the first plane (P1); the angle (α1) formed by the first middle section (26) with respect to an extension line extending in the tip-end direction from a site on the tip-end side of the base section (23) is more than 0° and less than 90°; and the axial center of the distal-end section (30) is separated from the extension of the line of the axial center of the second middle section (28).

Description

[Technical field]

[0001] The present invention relates to a catheter to be inserted into a body lumen. [Background technology]

[0002] Currently, interventions are performed to treat lesions in the heart, blood vessels, liver, brain, digestive system, urinary system, etc., using long catheters inserted into blood vessels through holes made in the skin.

[0003] For example, when a lesion is present in the liver, a treatment may be performed in which an embolic agent or a drug is supplied to the lesion through a treatment catheter inserted close to the hepatic artery. In such a treatment, it is desirable to use a guiding catheter so that the treatment catheter can fully function at the desired position. The guiding catheter can provide a backup force to the treatment catheter so as to mitigate the reaction caused by the insertion of the treatment catheter and to hold the treatment catheter in the desired position.

[0004] For example, Patent Document 1 describes a catheter having a tip portion that is wound on a plane perpendicular to a substantially linear base portion on the tip side of the base portion. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Pat. No. 4,169,464 Summary of the Invention [Problem to be solved by the invention]

[0006] Before reaching the target site, the catheter may pass through bent sections such as junctions, branches, and blood vessels that bend sharply. After passing through such bent sections, the catheter must continue on to the next blood vessel.

[0007] The present invention has been made to solve the above-mentioned problems, and has an object to provide a catheter that has high transmission of pushing force and can be oriented in a desired direction in a blood vessel beyond a curved blood vessel. [Means for solving the problem]

[0008] A catheter according to the present invention for achieving the above object is a catheter having a tubular body that communicates from a base end to a tip end, the tubular body having a substantially linear base portion and a shaped portion connected to the tip side of the base portion, the shaped portion having a first curved portion that curves distally beyond the base portion, a first intermediate portion located distally beyond the first curved portion, a second curved portion that curves distally beyond the first intermediate portion, a second intermediate portion located distally beyond the second curved portion, a third curved portion that curves distally beyond the second intermediate portion, and a third curved portion that curves distally beyond the third intermediate portion. the first curved portion and the first intermediate portion are located on a first plane, the second curved portion and the second intermediate portion are located on a second plane different from the first plane, an angle that the first intermediate portion forms with an extension line extending from a distal end portion of the base portion in a distal direction is greater than 0° and less than 90°, an axis of the most distal portion is away from an extension line of the axis of the second intermediate portion, and the tubular body is coated on an outer circumferential surface thereof from the most distal end toward the base end with a lubricating coating. The material of the tubular body is any one or a combination of two or more of styrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, trans-polyisoprene-based, fluororubber-based, or chlorinated polyethylene-based thermoplastic elastomer, polyether ketone, or polyimide-based materials, and the material of the lubricating coat is any one or a combination of two or more of glycidyl acrylate, glycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, β-methylglycidyl methacrylate, or is a copolymer of an epoxy group-containing monomer which is allyl glycidyl ether and a hydrophilic monomer which is N-methylacrylamide, N,N-dimethylacrylamide, or acrylamide; a copolymer composed of the above hydrophilic monomer; a cellulose-based polymeric substance which is hydroxypropyl cellulose or carboxymethyl cellulose; a polysaccharide; polyvinyl alcohol; a methyl vinyl ether-maleic anhydride copolymer; poly(2-hydroxyethyl (meth)acrylate); polyethylene glycol; polyacrylamide; or a combination of two or more of polyvinylpyrrolidone. It is characterized by: Effect of the Invention

[0009] In the catheter configured as described above, the angle that the first intermediate section makes with respect to the extension line extending from the distal end portion of the base section toward the distal end is greater than 0° and less than 90°, so that the pushing force can be easily transmitted to the distal end side. Also, since the axis of the most distal section is away from the extension line of the axis of the second intermediate section, the most distal section can be oriented in a desired direction different from the direction in which the second intermediate section is oriented in the blood vessel beyond the bent part of the blood vessel.

[0010] The third curved portion may be bent from the base end side toward the tip side away from the first plane. This allows the catheter to face in a desired direction with respect to the blood vessel that faces a predetermined direction beyond the bent portion of the blood vessel. In addition, since the third curved portion is bent away from the first plane, the catheter is more likely to transmit a pushing force from the base end side of the catheter to the tip compared to when the catheter is bent toward the first plane. In addition, when the third curved portion is bent away from the first plane, the third curved portion is likely to be bent in a direction substantially opposite to the second curved portion. Therefore, when the second curved portion passes the bent portion of the blood vessel, the most distal portion can face in a direction substantially opposite to the bending direction of the bent portion of the blood vessel. Therefore, for example, when the blood vessel beyond the bent portion of the blood vessel is bent in a direction different from the bending direction of the bent portion, the most distal portion can face in a desired direction with respect to the blood vessel beyond the bent portion.

[0011] The third curved portion may be curved from the base end side toward the tip end side toward the side where the base portion is located with respect to the second plane. This allows the most distal end portion oriented by the third curved portion to be oriented in a desired direction with respect to the blood vessel facing in a predetermined direction when the first curved portion, the first intermediate portion, and the second curved portion are deformed to describe a three-dimensional spiral in a blood vessel.

[0012] The third curved portion may be curved from the base end side to the tip end side toward the side opposite to the side where the base portion is located with respect to the second plane. This allows the most distal end portion oriented by the third curved portion to be oriented in a desired direction with respect to the blood vessel heading in a predetermined direction beyond the bent portion of the blood vessel when the first curved portion, the first intermediate portion, and the second curved portion are deformed to describe a three-dimensional spiral in the blood vessel.

[0013] The direction in which the second curved portion curves may be counterclockwise from the base end to the tip when the catheter is viewed from the tip side parallel to the extending direction of the base portion. This allows the catheter inserted from an artery in the arm to overcome the curved portion of the blood vessel by utilizing the counterclockwise curvature of the second curved portion. Furthermore, the operator can effectively transmit the rotational force to the shaped portion of the catheter by applying a rotational force to the base end of the catheter in the direction in which the second curved portion curves toward the tip side (counterclockwise direction). Then, the rotation of the three-dimensional shaped portion of the catheter allows the catheter to easily overcome the curved portion of the blood vessel.

[0014] The direction in which the second curved portion curves may be clockwise from the base end to the tip when the catheter is viewed from the tip side parallel to the extending direction of the base portion. This allows the catheter inserted from the leg artery to overcome the curved portion of the blood vessel by utilizing the clockwise curvature of the second curved portion. Furthermore, the operator can effectively transmit the rotational force to the shaped portion of the catheter by applying a rotational force to the base end of the catheter in the direction in which the second curved portion curves toward the tip side (clockwise direction). Then, the rotation of the three-dimensional shaped portion of the catheter allows the catheter to easily overcome the curved portion of the blood vessel.

[0015] The second curved portion may have a smaller minimum radius of curvature than the first curved portion, and the third curved portion may have a smaller minimum radius of curvature than the second curved portion. Therefore, when the catheter is advanced from the left subclavian artery to the descending aorta, the first curved portion contacts the upper side of the left subclavian artery, and the second curved portion contacts the ascending aorta side and the aortic arch vascular wall on the thoracic side. Since the third curved portion is floating in the aorta and faces the dorsal side in the descending aorta with the entire shaped portion stable, the catheter can be easily advanced into the descending aorta even without a guidewire. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a plan view showing a catheter according to a first embodiment. [Diagram 2]2A and 2B are views showing the tip of the catheter according to the first embodiment, in which (A) is a plan view, (B) is a view taken along the line B in FIG. 2A, and (C) is a view taken along the line C in FIG. 2A. [Diagram 3] FIG. 1 is a schematic diagram showing the placement of a catheter in a blood vessel when approached from the femoral artery. [Figure 4] FIG. 1 is a schematic diagram showing a catheter approaching the femoral artery and being inserted into the celiac artery, where (A) is a side view and (B) is a cross-sectional view taken along line DD in (A). [Diagram 5] FIG. 11 is a plan view showing a catheter according to a second embodiment. [Figure 6] 6A and 6B are diagrams showing the tip portion of a catheter according to a second embodiment, where (A) is a plan view, (B) is a view taken along the line B in FIG. 6A, and (C) is a view taken along the line C in FIG. 6A. [Figure 7] FIG. 1 is a schematic diagram showing the placement of a catheter in a blood vessel when approaching from an artery in the left arm. [Figure 8] Schematic diagram showing a catheter approaching from an artery in the left arm. (A) shows the catheter inserted into the aortic arch from the left subclavian artery, and (B) shows the catheter reaching the descending aorta. [Figure 9] FIG. 1 is a schematic diagram showing a catheter being inserted into the celiac artery via an arm artery, where (A) is a side view and (B) is a cross-sectional view taken along line EE of (A). [Figure 10] FIG. 11 is a cross-sectional view showing another example of a state in which a catheter approaching an arm artery is inserted into the celiac artery. [Figure 11] FIG. 13 is a schematic diagram showing a state in which a catheter approached from an arm artery is engaged with the celiac artery. [Figure 12] FIG. 1 is a schematic diagram showing a catheter being inserted into the aorta via an artery in the right arm. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the dimensional ratios in the drawings may be exaggerated for convenience of explanation and may differ from the actual ratios. In addition, in this specification and the drawings, components having substantially the same functions are given the same reference numerals to avoid duplicated explanations. In this specification, the side of the device that is inserted into the blood vessel is referred to as the "distal side" and the side that is operated is referred to as the "base side".

[0018] First Embodiment As shown in Fig. 3, the catheter 1 according to the first embodiment is a so-called guiding catheter for guiding a long device (e.g., a microcatheter for treatment) to a target location, that is, a common hepatic artery 105. The catheter 1 is introduced into a blood vessel from an artery 100 in a patient's leg (e.g., a femoral artery) and directed toward the vicinity of the common hepatic artery 105. Depending on the shape of blood vessels in the arm or abdomen, the catheter 1 may be introduced into a blood vessel from an artery in the arm and directed toward the vicinity of the common hepatic artery 105. The catheter 1 may be a so-called angiography catheter, a guidewire support catheter, or a microcatheter.

[0019] As shown in FIGS. 1 and 2, the catheter 1 has a tubular body 2, a hub 5 disposed on the proximal end side of the tubular body 2, and an anti-kink protector 4.

[0020] The tubular body 2 is long and flexible. A lumen 21 is formed in the approximate center of the tubular body 2, extending from the base end to the tip end.

[0021] The hub 5 has a passage formed therein that communicates with the lumen 21. The hub 5 can be used, for example, to insert or remove a guidewire 6 or a therapeutic catheter 7 (see Figs. 3 and 4(A)). The hub 5 can also be used to inject various liquids, such as an X-ray contrast medium, a medicinal solution, an anticancer drug, or saline, or an embolic material, such as embolic beads or an embolic coil, or a mixture thereof.

[0022] The anti-kink protector 4 is made of an elastic material. The anti-kink protector 4 covers the portion where the tubular body 2 and the hub 5 are connected. In this way, the anti-kink protector 4 prevents bending or kinking of the tubular body 2 in the vicinity of that portion.

[0023] Next, the tubular body 2 will be described in detail. The tubular body 2 has a substantially linear base portion 23 and a shaped portion 24 that is connected to and shaped on the tip side of the base portion 23. The shaped portion 24 has a first curved portion 25, a first intermediate portion 26, a second curved portion 27, a second intermediate portion 28, a third curved portion 29, and a most distal portion 30.

[0024] The first curved portion 25 is curved within a plane while extending from the tip of the base portion 23 toward the tip side. The first intermediate portion 26 extends from the tip of the first curved portion 25 toward the tip side in a substantially straight line.

[0025] The second curved portion 27 is curved in a plane while extending from the tip of the first intermediate portion 26 toward the tip side. The second curved portion 27 is curved in a direction different from the direction in which the first curved portion 25 is curved. The second intermediate portion 28 extends in a substantially straight line from the tip of the second curved portion 27 toward the tip side. The direction in which the second curved portion 27 is curved is clockwise from the base end toward the tip when the catheter 1 is viewed from the tip side parallel to the extension direction X of the base portion 23. The direction in which the second curved portion 27 is curved may be counterclockwise from the base end toward the tip when the catheter 1 is viewed from the tip side parallel to the extension direction X.

[0026] The third curved portion 29 extends from the tip of the second intermediate portion 28 toward the tip side and is curved within a plane. The most-distal portion 30 extends in a substantially straight line from the tip of the third curved portion 29 toward the tip side. At the tip of the most-distal portion 30, the lumen 21 opens to form a tip opening 31. The axis of the most-distal portion 30 is not located on an extension of the axis of the second intermediate portion 28.

[0027] The angle α1 that the first intermediate portion 26 makes with respect to an extension line extending from the tip side portion of the base portion 23 toward the tip side is greater than 0° and less than 90°, and is preferably 40° to 85°, and more preferably 40° to 80°. When the angle α1 is less than 90°, it is easy to insert into a merging portion, a branching portion, or a blood vessel that bends sharply (hereinafter, these will be referred to as a bent portion), and it is easy to transmit a pushing force to the tip side.

[0028] The angle α2 that the second intermediate portion 28 makes with respect to an extension line extending from the first intermediate portion 26 toward the tip side is not particularly limited, but is generally parallel or greater than 0° and less than 180°, preferably 100° to 175°, and more preferably 110° to 170°.

[0029] The angle α3 that the most distal portion 30 makes with respect to an extension line extending distally from the second intermediate portion 28 is not particularly limited, but is greater than 0° and less than 180°, preferably 5° to 80°, and more preferably 10° to 60°. The most distal portion 30 and the second intermediate portion 28 are not positioned coaxially.

[0030] The axis centers of the tip side portion of the base portion 23, the first curved portion 25, and the first intermediate portion 26 are located on the first plane P1. The axis centers of the second curved portion 27 and the second intermediate portion 28 are located on the second plane P2. The axis centers of the third curved portion 29 and the most distal portion 30 are located on the third plane P3. The axis center of the first intermediate portion 26 located on the first plane P1 may also be located on the second plane P2. The axis center of the second intermediate portion 28 located on the second plane P2 may also be located on the third plane P3.

[0031] The second plane P2 is a plane different from the first plane P1. The angle β of the second plane P2 with respect to the first plane P1 on the distal side of the first curved portion 25 is more than 0° and less than 180°, preferably 30° to 150°, and more preferably 80° to 100°. Since the second plane P2 is different from the first plane P1, the shaped portion 24 having the first curved portion 25 and the second curved portion 27 can have a twisted shape that draws a three-dimensional spiral. Therefore, the shaped portion 24 of the catheter 1 is easily aligned with the inner wall surface of the blood vessel, and the posture within the blood vessel is easily stabilized. In addition, when the base end portion of the catheter 1 is rotated in the direction in which the catheter 1 is wound toward the distal end side, the rotational force is efficiently transmitted to the distal end side, making it easy to push the catheter 1 toward the distal end.

[0032] The third plane P3 is a plane different from the first plane P1 and the second plane P2. The third plane P3 may coincide with the second plane P2, but it is preferable that the third plane P3 does not coincide with the second plane P2. By not coinciding with the second plane P2, the distal end opening 31 of the most distal portion 30 can be oriented in a direction different from the curvature of the second curved portion 27.

[0033] In this embodiment, the third curved portion 29 is bent from the base end side toward the tip end side toward the side away from the first plane P1. Therefore, the most distal portion 30 extends from the base end side toward the tip opening 31 so as to move away from the first plane P1. Also, the third curved portion 29 is bent from the base end side toward the tip end side toward the opposite side of the side where the base portion 23 is located with respect to the second plane P2. Therefore, the most distal portion 30 extends from the base end side toward the tip opening 31 toward the opposite side of the side where the base portion 23 is located with respect to the second plane P2. Note that the third curved portion 29 may be bent toward the side approaching the first plane P1 from the base end side toward the tip end side. Also, the third curved portion 29 may be bent on a plane parallel to the first plane P1 from the base end side toward the tip end side. Also, the third curved portion 29 may be bent from the base end side toward the tip end side toward the opposite side of the side where the base portion 23 is located from the second plane P2.

[0034] It should be noted that the first intermediate portion 26, the second intermediate portion 28 and the most distal portion 30 need only be substantially linear, and do not have to be formed in strictly straight lines.

[0035] If the minimum radius of curvature in the first curved portion 25 is R1, the minimum radius of curvature in the second curved portion 27 is R2, and the minimum radius of curvature in the third curved portion 29 is R3, then R1>R2>R3 is satisfied. That is, R2 is smaller than R1, and R3 is smaller than R2. The minimum radius of curvature is the radius of curvature of the portion with the smallest radius of curvature among the curved portions.

[0036] The tubular body 22 may or may not have a reinforcing body embedded in the range from the base end to a predetermined position in the tip direction. The reinforcing body is formed by braiding a plurality of wires into a tubular shape. The position of the tip of the reinforcing body is not particularly limited, and may be located in the shaped portion 24 or the base portion 23.

[0037] The outer diameter of the tubular body 2 is preferably 1 mm (3 Fr) to 2.5 mm (6 Fr), more preferably 1.3 mm (4 Fr) to 1.8 mm (5 Fr). The effective length of the tubular body 2 is preferably 800 to 1800 mm, more preferably 1000 to 1800 mm, and even more preferably 1000 to 1500 mm. It is preferable that the tubular body 2 can be appropriately selected depending on the patient, the blood vessel into which it is introduced, and the like. The effective length is the length of a portion that can be inserted into a blood vessel, a sheath, and the like. In this embodiment, the effective length is the length from the most distal end of the anti-kink protector 4 to the most distal end of the tubular body 2.

[0038] The tubular body 2 may have a distal tip, which is more flexible than the proximal end, disposed at the distal end. The distal tip is made of a flexible material such as rubber or elastomer. The number of layers constituting the tubular body 2, the materials constituting each layer, the presence or absence of a reinforcing body, etc. may vary along the longitudinal direction of the tubular body 2.

[0039] Alternatively, the tubular body 2 may have a flexible portion on the distal side of the reinforcement portion in which the reinforcement is embedded, where no reinforcement is provided. The catheter 1 is provided with a flexible portion, so that the catheter 1 can move in a bent, curved, or branched blood vessel without damaging the blood vessel. The length of the flexible portion is preferably 500 mm or less, and more preferably 10 to 200 mm. For example, in the case of a 4 Fr catheter 1, the length of the flexible portion is 150 mm. In the case of a 5 Fr catheter 1, the length of the flexible portion is 150 mm.

[0040] Examples of the material constituting the tubular body 2 include various thermoplastic elastomers such as styrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, trans-polyisoprene-based, fluororubber-based, and chlorinated polyethylene-based, polyether ketone, and polyimide-based materials, and one or a combination of two or more of these materials (polymer alloy, polymer blend, laminate, etc.) can be used. A low-friction material may be disposed on the inner peripheral surface of the tubular body 2 so that the guide wire 6, other catheters, and the like can be easily inserted into the lumen 21. The low-friction material is, for example, a fluorine-based resin material such as polytetrafluoroethylene (PTFE). The tubular body 2 may contain an X-ray contrast material.

[0041] Next, a method of using the catheter 1 according to this embodiment will be described using an example in which the catheter 1 is inserted into a blood vessel via the femoral artery 100 and engaged with the celiac artery 104.

[0042] In the procedure, the surgeon inserts a guidewire 6 into the femoral artery 100 as shown in FIG. 3. Next, the surgeon pushes the catheter 1, which houses the guidewire 6 in its lumen 21, along the guidewire 6. Usually, the tip of the guidewire 6 precedes the tip of the catheter 1. Therefore, the shaped portion 24 of the catheter 1 is deformed into a shape close to a straight line by the guidewire 6 in the lumen 21. As a result, the catheter 1 moves up the descending aorta 103 toward the upper side Y2 (the side closer to the heart) and reaches the vicinity of the celiac artery 104.

[0043] After the guidewire 6 and the catheter 1 reach the vicinity of the entrance of the celiac artery 104, the surgeon retracts the guidewire 6 to accommodate the guidewire 6 in the lumen 21 of the catheter 1. As a result, as shown in FIG. 4, the shaped portion 24 of the catheter 1 is restored to its original three-dimensionally curved shape. The surgeon can insert the tip of the catheter 1 into the celiac artery 104 by utilizing the curved shape of the shaped portion 24. The celiac artery 104 extends generally anteriorly Z (ventral side) from the descending aorta 103. The common hepatic artery 105, the left gastric artery 106, and the splenic artery 107 branch off from the celiac artery 104. The common hepatic artery 105 generally extends from the celiac artery 104 to the lower side Y1 (the side closer to the lower limbs) and then extends obliquely upward toward the liver. The left gastric artery 106 and the splenic artery 107 generally extend superiorly Y2 (closer to the head) from the celiac trunk 104.

[0044] The first curved portion 25, the first intermediate portion 26, and the second curved portion 27 of the catheter 1 can stably contact the vascular wall of the descending aorta 103 by drawing a three-dimensional spiral. At this time, the first curved portion 25 and / or the second curved portion 27 may be deformed so that the radius of curvature becomes larger or smaller. The first intermediate portion 26 may be curved. The second curved portion 27 of the catheter 1 contacts the vascular wall of the descending aorta 103 on the opposite side to the entrance of the celiac artery 104, and the second intermediate portion 28 and / or the third curved portion 29 contacts the vascular wall of the celiac artery 104. As a result, the second intermediate portion 28 and / or the third curved portion 29 of the catheter 1 are engaged with the celiac artery 104. In this state, the catheter 1 is provided with the third curved portion 29, so that the most distal portion 30 can extend from the celiac artery 104 to the lower side Y1 and then extend toward the common hepatic artery 105, which extends obliquely upward toward the liver. The third curved portion 29 and / or the most distal portion 30 may, but need not, come into contact with the vascular wall of the common hepatic artery 105.

[0045] After this, a treatment catheter 7 longer than the catheter 1 is inserted from the hub 5 into the lumen 21 of the catheter 1. The surgeon can easily insert the treatment catheter 7 into the common hepatic artery 105 by protruding it from the tip of the catheter 1. At this time, since the tip of the catheter 1 faces downward Y1 from the celiac artery 104, it is possible to prevent the treatment catheter 7 from being erroneously inserted into the left gastric artery 106 or the splenic artery 107, which are simply facing upward Y2. After this, the surgeon can insert the treatment catheter 7 into the common hepatic artery 105 and release an embolic agent or a medicinal solution through the treatment catheter 7. The catheter 1 relieves the reaction caused by the insertion of the treatment catheter 7. Furthermore, the catheter 1 can provide a backup force to the treatment catheter 7 so as to hold the treatment catheter 7 in a desired position. Note that the medical device inserted into the catheter 1 does not have to be the treatment catheter 7.

[0046] <Second embodiment> The catheter 1 according to the second embodiment differs from the first embodiment in that it is introduced into a blood vessel from an artery in a patient's arm and directed toward the vicinity of the common hepatic artery 105. The catheter 1 according to the second embodiment may be introduced into a blood vessel from an artery 100 in a patient's leg and directed toward the vicinity of the common hepatic artery 105.

[0047] 5 and 6, in the catheter 1 according to the second embodiment, the second curved portion 27 curves counterclockwise from the base end to the tip when the catheter 1 is viewed from the tip side parallel to the extending direction X of the base portion 23. Moreover, the third curved portion 29 curves from the base end side to the tip side toward the side where the base portion 23 is located with respect to the second plane P2.

[0048] The outer diameter of the tubular body 2 is preferably 1 mm (3 Fr) to 2.5 mm (6 Fr), more preferably 1.3 mm (4 Fr) to 1.8 mm (5 Fr). The effective length of the tubular body 2 is preferably 1000 to 1800 mm, more preferably 1100 to 1800 mm, and even more preferably 1000 to 1500 mm, when inserted from the radial artery of the arm. It is preferable that the tubular body 2 can be appropriately selected depending on the patient, the blood vessel to be introduced, and the like. The effective length is the length of the portion that can be inserted into a blood vessel, a sheath, and the like. In this embodiment, the effective length is the length from the tip of the anti-kink protector 4 to the tip of the tubular body 2. The effective length in the embodiment is 1200 mm or 1250 mm.

[0049] The tubular body 2 may have a distal tip disposed at its distal end, which is more flexible than the proximal end. The distal tip is made of a flexible material such as rubber or elastomer. The number of layers constituting the tubular body 2, the materials constituting each layer, the presence or absence of a reinforcing member 40, etc. may vary along the longitudinal direction of the tubular body 2. The tubular body 2 may or may not have a reinforcing member 40.

[0050] Alternatively, the tubular body 2 may have a flexible section 42 in which the reinforcing body 40 is not provided, on the distal side of the reinforcing section 41 in which the reinforcing body 40 is embedded. The shaped section 24 has a distal side reinforcing section 43 in which the reinforcing body 40 is provided, and a flexible section 42. The distal side reinforcing section 43 is a portion on the distal side of the reinforcing section 41. By providing the flexible section 42, the catheter 1 can move in a bent, bent, or branched blood vessel without damaging the blood vessel. The length of the flexible section 42 is preferably 500 mm or less, more preferably 10 to 200 mm, more preferably 10 mm to 50 mm, and more preferably 11 mm to 47 mm. For example, in the case of a 4Fr catheter 1, the length of the flexible section 42 is 23 mm. In the case of a 5Fr catheter 1, the length of the flexible section 42 is 23 mm.

[0051] The other configurations are the same as those in the first embodiment, and therefore will not be described.

[0052] Next, a method of using the catheter 1 according to the second embodiment will be described taking as an example a case where the catheter 1 is inserted into a blood vessel from an artery 101 in the left arm and engaged with the celiac artery 104 as shown in Fig. 7. The arteries of the arm to which the catheter 1 approaches include, for example, the distal radial artery, the conventional radial artery, the ulnar artery, the distal ulnar artery, the brachial artery, and the snuff box radial artery.

[0053] In the procedure, the surgeon inserts the guidewire 6 into the artery 101 in the left arm. Next, the surgeon pushes the catheter 1, which houses the guidewire 6 in its lumen 21, along the guidewire 6. Normally, the tip of the guidewire 6 precedes the tip of the catheter 1. Therefore, the shaped portion 24 of the catheter 1 is deformed into a shape close to a straight line by the guidewire 6 in the lumen 21.

[0054] As shown in FIG. 7 and FIG. 8(A), the guide wire 6 and the catheter 1 pass through the left subclavian artery 102 and advance to the aortic arch 110. At the site where the left subclavian artery 102 is connected to the aortic arch 110, the catheter 1 needs to be largely bent in order to advance to the descending aorta 103. To deal with this, for example, the surgeon can temporarily retract the guide wire 6 and accommodate the guide wire 6 in the lumen 21 of the catheter 1. This causes the shaped portion 24 of the catheter 1 to restore its original three-dimensionally curved shape. The surgeon can advance the tip of the catheter 1 from the aortic arch 110 toward the descending aorta 103 by utilizing the curved shape of the shaped portion 24. That is, the most distal end portion 30 of the catheter 1 can be directed toward the descending aorta 103 beyond the aortic arch 110 in the aortic arch 110 that is bent in a direction substantially opposite to the direction of bending from the left subclavian artery 102 to the aortic arch 110. Next, the surgeon pushes in the catheter 1, and as shown in FIG. 8(B), the catheter 1 can be easily pushed from the aortic arch 110 to the descending aorta 103. After this, the surgeon protrudes the guide wire 6 from the catheter 1. Next, the surgeon further pushes the catheter 1 along the guide wire 6. The catheter 1 moves down the descending aorta 103 to the lower side Y1 (the side closer to the lower limbs) and reaches the vicinity of the celiac artery 104.

[0055] Furthermore, the catheter 1 has a shaped portion 24 that is easily oriented from the left subclavian artery 102 through the aortic arch 110 toward the descending aorta 103, so the guide wire 6 does not need to be inserted. At this time, the surgeon can move the tip of the catheter 1 toward the descending aorta 103 by the sensation of his / her hand alone, without the need for X-ray fluoroscopy. This makes it possible to reduce the amount of radiation exposure, which is one of the disadvantages of a procedure that approaches from the artery of the hand. Furthermore, the procedure time can be shortened, which reduces the burden on the patient and improves medical economics.

[0056] Incidentally, when approaching the catheter 1 from the left arm, the left arm is usually extended to the left relative to the body. However, this catheter 1 can be moved from the left subclavian artery 102 through the aortic arch 110 to the descending aorta 103 even when the left arm is placed on the abdomen. Therefore, the surgeon can perform the procedure on the right side of the patient's body, and there is no need to change the layout of the catheter lab.

[0057] When the tubular body 2 has a reinforcing portion 41 and a flexible portion 42, and the length of the flexible portion 42 is about 23 mm, the area reinforced by the reinforcing body 40 at the tip of the catheter 1 is wide, so that the tip of the catheter 1 can be easily directed to the descending aorta 103. Therefore, it is effective that the length of the flexible portion 42 is about 23 mm in the catheter 1 inserted from the arm artery 101 rather than the femoral artery 100. In the case of the catheter 1 inserted from the femoral artery 100, since it is not necessary to insert the catheter 1 from the subclavian artery 102 to the descending aorta 103, the length of the flexible portion 42 is, for example, about 150 mm, so that the tip of the catheter 1 is flexible. In contrast, in the case of the catheter 1 inserted from the arm artery 101 rather than the femoral artery 100, in addition to the shaped portion 24 that is easily directed from the left subclavian artery 102 to the descending aorta 103, the catheter 1 has a moderately hard structure with a flexible portion 42 having a length of about 23 mm, so that it can be moved to the descending aorta 103 more easily.

[0058] After the guidewire 6 and the catheter 1 reach the vicinity of the entrance of the celiac artery 104, the surgeon retracts the guidewire 6 to accommodate the guidewire 6 in the lumen 21 of the catheter 1. This causes the shaped portion 24 of the catheter 1 to restore to its original three-dimensionally curved shape, as shown in Fig. 9. The surgeon can insert the tip of the catheter 1 into the celiac artery 104 by utilizing the curved shape of the shaped portion 24.

[0059] The first curved portion 25, the first intermediate portion 26, and the second curved portion 27 of the catheter 1 can stably contact the vascular wall of the descending aorta 103 by drawing a three-dimensional spiral. At this time, the first curved portion 25 and / or the second curved portion 27 may be deformed so that the radius of curvature becomes larger or smaller. The first intermediate portion 26 may be curved. For example, as shown in FIG. 10, even if the second curved portion 27 has a curvature radius R2 of about 10 to 20 mm and is curved sharply, kinking of the catheter 1 can be prevented due to the presence of the reinforcing member 40. As shown in FIGS. 9 and 10, the second curved portion 27 of the catheter 1 contacts the vascular wall of the descending aorta 103 on the opposite side to the entrance of the celiac artery 104, and the second intermediate portion 28 and / or the third curved portion 29 contacts the vascular wall of the celiac artery 104. The second curved portion 27 contacts the vascular wall of the rear side (opposite side to the front side Z) of the celiac artery 104. As a result, the second intermediate section 28 and / or the third curved section 29 of the catheter 1 are engaged with the celiac artery 104. In this state, the third curved section 29 is provided in the catheter 1, so that the most distal section 30 of the catheter 1 extends in a direction different from that of the second curved section 27. Therefore, the most distal section of the catheter 1 can be directed toward the common hepatic artery 105 extending downward Y1 from the celiac artery 104. Alternatively, the catheter 1 can be easily advanced toward a proper hepatic artery (not shown) branching from the common hepatic artery 105. That is, the distal opening 31 of the most distal section 30 of the catheter 1 can be directed toward the common hepatic artery 105 that bends in a direction substantially opposite to the bending direction from the descending aorta 103 to the celiac artery 104. The third curved section 29 and / or the most distal section 30 may or may not contact the vascular wall of the common hepatic artery 105.

[0060] The flexible portion 42 contacts the vascular wall at the entrance of the celiac artery 104 on the opposite side of the descending aorta 103 with which the reinforced portion 41 contacts. That is, the portion where the tip of the reinforced portion 41 is located floats in the descending aorta 103 without contacting the vascular wall. Since the reinforcement body 40 is not provided up to the third curved portion 29 and the most distal portion 30, the tip of the catheter 1 is flexible. Therefore, it is easy to change the direction of the tip of the catheter 1 along the guide wire 6, or to control the direction of the most distal portion 30 by inserting and removing the guide wire 6 relative to the catheter 1. The length along the axis of the shaped portion 24 (the length along the axis from the base end of the shaped portion 24 to the tip opening 31) is the sum of the length L1 along the axis of the tip side reinforcement portion 43 and the length L2 along the axis of the flexible portion 42, and is preferably 30 to 50 mm. The ratio L2 / (L1+L2) of the length L2 of the flexible portion 42 to the length (L1+L2) of the shaped portion 42 is preferably 0.36 to 0.93.

[0061] The catheter 1 may be coated with a lubricating coating from the tip opening 31 along the axis toward the base end. The lubricating coating is applied, for example, over a range of up to 400 mm from the tip opening 31 along the axis toward the base end. This allows the surgeon to insert the catheter 1 deeply into the common hepatic artery 105. Examples of materials constituting the lubricating coating include copolymers of epoxy group-containing monomers such as glycidyl acrylate, glycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, β-methylglycidyl methacrylate, and allyl glycidyl ether with hydrophilic monomers such as N-methylacrylamide, N,N-dimethylacrylamide, and acrylamide; (co)polymers composed of the above-mentioned hydrophilic monomers; cellulose-based polymeric substances such as hydroxypropyl cellulose and carboxymethyl cellulose; polysaccharides, polyvinyl alcohol, methyl vinyl ether-maleic anhydride copolymers, water-soluble polyamides, poly(2-hydroxyethyl (meth)acrylate), polyethylene glycol, polyacrylamide, and polyvinylpyrrolidone.

[0062] Thereafter, the surgeon can rotate the base end (e.g., hub 5) of the catheter 1 in a direction in which the shaped portion 24 winds toward the tip side. This allows the rotational force to be efficiently transmitted to the tip side along the spiral of the shaped portion 24, and the most distal portion 30 can be satisfactorily pushed deep into the common hepatic artery 105, as shown in Fig. 11. As a result, the most distal portion 30 of the shaped portion 24 of the catheter 1 is disposed in the common hepatic artery 105 with the shaped portion 24 satisfactorily engaged with the wall surface of the celiac artery 104. The tip opening 31 then opens toward the blood vessel beyond the common hepatic artery 105.

[0063] Thereafter, a treatment catheter 7, which is longer than the catheter 1, is inserted from the hub 5 into the lumen 21 of the catheter 1. The surgeon projects the treatment catheter 7 from the tip of the catheter 1, and can easily insert it into the common hepatic artery 105. At this time, the most distal end 30 of the catheter 1 faces the lower side Y1 from the celiac artery 104, which extends downward Y1 and then diagonally upward toward the liver, so that the treatment catheter 7 can be prevented from being erroneously inserted into the left gastric artery 106 or the splenic artery 107, which simply face the upper side Y2. The procedure thereafter is substantially the same as that in the case where the catheter 1 is approached from the femoral artery 100 described above, and therefore a description thereof will be omitted.

[0064] Next, a method of using the catheter 1 according to the second embodiment will be described using an example in which the catheter 1 is inserted into a blood vessel from an artery 111 in the right arm and engaged with the celiac artery 104, as shown in FIG.

[0065] In the procedure, the surgeon inserts the guidewire 6 into the artery 111 of the right arm. Next, the surgeon pushes the catheter 1, which houses the guidewire 6 in the lumen 21, along the guidewire 6. Normally, the tip of the guidewire 6 precedes the tip of the catheter 1. Therefore, the shaped portion 24 of the catheter 1 is deformed into a shape close to a straight line by the guidewire 6 in the lumen 21.

[0066] The guidewire 6 and the catheter 1 pass through the brachiocephalic artery 112 and advance to the aortic arch 110. At the site where the brachiocephalic artery 112 connects to the aortic arch 110, the catheter 1 needs to bend significantly to head toward the descending aorta 103. To deal with this, for example, the surgeon can temporarily retract the guidewire 6 and accommodate the guidewire 6 in the lumen 21 of the catheter 1. This causes the shaped portion 24 of the catheter 1 to restore its original three-dimensionally curved shape. The surgeon can advance the tip of the catheter 1 from the aortic arch 110 toward the descending aorta 103 by utilizing the curved shape of the shaped portion 24. That is, the distal end portion 30 of the catheter 1 can be directed toward the descending aorta 103 beyond the aortic arch 110 in the aortic arch 110 that bends in a direction substantially opposite to the direction of bending from the brachiocephalic artery 112 to the aortic arch 110. After this, the surgeon protrudes the guidewire 6 from the catheter 1. Next, the operator pushes the catheter 1 along the guide wire 6. This allows the catheter 1 to easily advance from the aortic arch 110 to the descending aorta 103. The catheter 1 moves down the descending aorta 103 to the lower side Y1 (the side closer to the lower limb) and reaches the vicinity of the celiac artery 104. The engagement of the catheter 1 with the celiac artery 104 is almost the same as when the catheter 1 is approached from the artery 101 of the left arm, so a description thereof will be omitted. The present catheter 1 can be easily advanced extremely in Type I, in which the difference in height between the brachiocephalic artery and the aortic root is equal to or less than the common carotid artery diameter, and in Type II, in which the difference in height is greater than the same and less than three times. Furthermore, even in the case of Type III, in which the catheter 1 is positioned lower Y1 than the common carotid artery and the aortic root, the catheter 1 can be advanced from the brachiocephalic artery 112 through the aortic arch 110 toward the descending aorta 103.

[0067] In general, in the case of Type III blood vessels, a pigtail-type guiding catheter is first inserted into the descending aorta, and then the guiding catheter is replaced with a cobra-type guiding catheter that can engage with the celiac artery along the guide wire 6. In this case, since the guiding catheter needs to be replaced, the procedure time is long, and the number of catheters used increases. In contrast, the first and second embodiments have the effect of shortening the procedure time and reducing the number of guiding catheters used, thereby reducing costs.

[0068] As described above, the catheter 1 according to the first and second embodiments is a catheter 1 having a tubular body 2 that communicates from the base end to the tip, and the tubular body 2 has a substantially linear base portion 23 and a shaped portion 24 connected to the tip side of the base portion 23. The shaped portion 24 has a first curved portion 25 that curves further to the tip side than the base portion 23, a first intermediate portion 26 that is located further to the tip side than the first curved portion 25, a second curved portion 27 that curves further to the tip side than the first intermediate portion 26, a second intermediate portion 28 that is located further to the tip side than the second curved portion 27, and a second intermediate portion 29 that is located further to the tip side than the second intermediate portion 28. The distal end portion 30 has a third curved portion 29 that curves at the end side, and a distal end portion 30 that is located more distal than the third curved portion 29 and has a distal opening 31 formed therein, the first curved portion 25 and the first intermediate portion 26 are located on a first plane P1, the second curved portion 27 and the second intermediate portion 28 are located on a second plane P2 different from the first plane P1, the angle α1 that the first intermediate portion 26 makes with respect to an extension line extending from the distal end portion of the base portion 23 toward the distal end is greater than 0° and less than 90°, and the axis of the distal end portion 30 is away from the extension line of the axis of the second intermediate portion 28.

[0069] The catheter 1 configured as described above can easily transmit a pushing force to the tip side because the angle α1 that the first intermediate portion 26 makes with respect to the extension line extending from the tip side portion of the base portion 23 toward the tip side is greater than 0° and less than 90°. In addition, since the axis of the most distal portion 30 is away from the extension line of the axis of the second intermediate portion 28, the most distal portion 30 can be oriented in a desired direction in the blood vessel beyond the bent portion of the blood vessel. This allows the catheter 1 to easily advance into the blood vessel beyond the bent portion of the blood vessel. In addition, the catheter 1 can effectively assist the advancement of other devices into the blood vessel beyond the bent portion of the blood vessel.

[0070] The third curved portion 29 may be bent away from the first plane P1 from the base end side to the tip side. This allows the catheter 1 to face in a desired direction with respect to the blood vessel that faces a predetermined direction beyond the bent portion of the blood vessel. In addition, since the third curved portion 29 is bent away from the first plane P1, the catheter 1 is more likely to transmit a pushing force from the base end side of the catheter 1 to the tip compared to when the catheter 1 is bent toward the first plane P1. In addition, when the third curved portion 29 is bent away from the first plane P1, the third curved portion 29 is likely to be bent in a direction substantially opposite to the second curved portion 27. Therefore, when the second curved portion 27 passes the bent portion of the blood vessel, the most distal portion 30 can face in a direction substantially opposite to the bending direction of the bent portion of the blood vessel. Therefore, for example, when the blood vessel beyond the bent portion of the blood vessel is bent in a direction different from the bending direction of the bent portion, the most distal portion 30 can face in an appropriate direction with respect to the blood vessel beyond the bent portion. For example, when approaching from an artery 101 in the left arm, the catheter 1 can pass through a bent portion between the left subclavian artery 102 and the aortic arch 110 and head toward the descending aorta 103, which bends in a substantially reverse direction beyond the bent portion. Also, for example, the catheter 1 can pass through a bent portion between the descending aorta 103 and a side branch (for example, the celiac artery 104) and easily reach a blood vessel (for example, the common hepatic artery 105) that bends in a substantially reverse direction beyond the bent portion. Note that, for example, the direction in which the blood vessel beyond the bent portion bends relative to the bending direction of the bent portion is not particularly limited. Therefore, even if the blood vessel beyond the bent portion bends in a substantially same direction as the bending direction of the bent portion, the catheter 1 can be directed in a desired direction in the blood vessel beyond the bent portion.

[0071] Furthermore, the third curved portion 29 may be curved from the base end side toward the tip end side toward the side where the base portion 23 is located with respect to the second plane P2. This allows the most distal portion 30, which is oriented by the third curved portion 29, to be oriented in a desired direction with respect to the blood vessel facing in a predetermined direction when the first curved portion 25, the first intermediate portion 26, and the second curved portion 27 are deformed so as to describe a three-dimensional spiral within the blood vessel.

[0072] Furthermore, the third curved portion 29 may be curved from the base end side toward the tip end side toward the side opposite to the side on which the base portion 23 is located with respect to the second plane P2. This allows the most distal portion 30, which is oriented by the third curved portion 29, to be oriented in a desired direction with respect to the blood vessel facing in a predetermined direction, when the first curved portion 25, the first intermediate portion 26, and the second curved portion 27 are deformed so as to describe a three-dimensional spiral within the blood vessel.

[0073] The direction in which the second curved portion 27 curves may be counterclockwise from the base end to the tip when the catheter 1 is viewed from the tip side parallel to the extending direction X of the base portion 23. This allows the catheter 1 to get past the bent portion of the blood vessel by utilizing the counterclockwise curvature of the second curved portion 27. Furthermore, the operator can effectively transmit the rotational force to the shaped portion 24 of the catheter 1 by applying a rotational force to the base end of the catheter 1 in the direction in which the second curved portion 27 curves toward the tip side (counterclockwise direction). Then, the rotation of the three-dimensional shaped portion 24 of the catheter 1 allows the catheter 1 to easily get past the bent portion of the blood vessel.

[0074] The direction in which the second curved portion 27 curves may be clockwise from the base end to the tip when the catheter 1 is viewed from the tip side parallel to the extending direction X of the base portion 23. This allows the catheter 1 to get past the bent portion of the blood vessel by utilizing the counterclockwise curvature of the second curved portion 27. Furthermore, the operator can effectively transmit the rotational force to the shaped portion 24 of the catheter 1 by applying a rotational force to the base end of the catheter 1 in the direction in which the second curved portion 27 curves toward the tip side (clockwise direction). Then, the rotation of the three-dimensional shaped portion 24 of the catheter 1 allows the catheter 1 to easily get past the bent portion of the blood vessel.

[0075] Furthermore, the minimum radius of curvature R2 of the second curved portion 27 is smaller than the minimum radius of curvature R1 of the first curved portion 25, and the minimum radius of curvature R3 of the third curved portion 29 is smaller than the minimum radius of curvature R2 of the second curved portion 27. Therefore, when the catheter 1 is advanced from the left subclavian artery 102 to the descending aorta 103, the first curved portion contacts the upper side of the left subclavian artery 102, and the second curved portion 27 contacts the vascular wall of the aortic arch 110 on the ascending aorta side and on the thoracic side. Since the entire shaped portion 24 is in a stable state and the third curved portion 29 faces the dorsal side at the descending aorta 103 while floating in the aorta, the catheter 1 can be easily advanced into the descending aorta 103 even without the guide wire 6.

[0076] The present invention is not limited to the above-mentioned embodiment, and various modifications can be made by those skilled in the art within the technical concept of the present invention. For example, the catheter 1 can be made to have different sizes depending on the inner diameter of the blood vessel. Alternatively, the flexible section 42 may have a resin whose hardness is gradually increased from the tip to the base end, or the thickness or pitch of the reinforcing body may be changed, or both may be combined.

[0077] Furthermore, the blood vessel engaged by the catheter 1 is not limited to the celiac artery 104. For example, the blood vessel engaged by the catheter 1 may be the superior mesenteric artery, the inferior mesenteric artery, the renal artery, the lumbar artery, the splenic artery, the left gastric artery, the testicular artery, the common iliac artery, the internal iliac artery, the prostatic artery, the uterine artery, the external iliac artery, the coronary artery, or the like. The catheter 1 may also be used to guide a device inserted into the carotid artery. The catheter 1 can easily pass through the blood vessel that is greatly curved between the right subclavian artery and the right common carotid artery.

[0078] The catheter 1 may also be an outer guiding catheter into which an inner catheter is inserted. The inner catheter is linear. Alternatively, the catheter 1 may be an inner catheter inserted into an outer guiding catheter, or a dilator. The inner catheter may have a soft tip and a rigid base.

[0079] This application is based on Japanese Patent Application No. 2019-179471 filed on September 30, 2019, the disclosures of which are hereby incorporated by reference in their entirety. [Explanation of symbols]

[0080] 1 Catheter 2 Tubular body 21 Lumens 23 Base 24 Shape part 25 First curved section 26 First Intermediate Section 27 Second curved section 28 Second Intermediate Section 29 Third curve 30 Cutting edge section 31 Tip opening 100 Leg Arteries 101 Left Arm Artery 102 Left subclavian artery 103 Descending aorta 104 Celiac artery 105 Common hepatic artery 110 Aortic Arch 111 Right Arm Artery P1 1st plane P2 2nd plane P3 3rd plane

Claims

1. A catheter having a tubular body communicating from a base end to a tip end, The tubular body has a substantially linear base portion and a shaped portion connected to a tip side of the base portion, The shape portion is A first curved portion curved toward the tip side relative to the base portion; A first intermediate portion located distally of the first curved portion; a second curved portion curved toward the distal end side relative to the first intermediate portion; A second intermediate portion located distally of the second curved portion; a third curved portion curved toward the distal end side relative to the second intermediate portion; a distal end portion located distally of the third curved portion and having a distal end opening formed therein, the first curved portion and the first intermediate portion lie in a first plane; the second curved portion and the second intermediate portion are located in a second plane different from the first plane, an angle formed by the first intermediate portion with respect to an extension line extending from a distal end portion of the base portion in a distal direction is greater than 0° and less than 90°; an axis of the tip end portion is away from an extension line of an axis of the second intermediate portion, The tubular body has an outer peripheral surface coated with a lubricating coating from the distal end toward the proximal end, the constituent material of the tubular body is any one or a combination of two or more of styrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, trans-polyisoprene-based, fluororubber-based, or chlorinated polyethylene-based thermoplastic elastomer, polyether ketone, or polyimide-based materials; The catheter is characterized in that the lubricating coating is made of one or a combination of two or more of the following: a copolymer of an epoxy group-containing monomer, which is glycidyl acrylate, glycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, 3,4-epoxycyclohexylmethyl methacrylate, β-methylglycidyl methacrylate, or allyl glycidyl ether, with a hydrophilic monomer, which is N-methylacrylamide, N,N-dimethylacrylamide, or acrylamide; a copolymer composed of the above hydrophilic monomers; a cellulose-based polymer substance, which is hydroxypropyl cellulose or carboxymethyl cellulose; a polysaccharide; polyvinyl alcohol; a methyl vinyl ether-maleic anhydride copolymer; poly(2-hydroxyethyl (meth)acrylate), polyethylene glycol, polyacrylamide, or polyvinylpyrrolidone.

2. The catheter according to claim 1 , wherein the third curved portion is curved away from the first plane from the base end side to the tip end side.

3. 3. The catheter according to claim 1, wherein the third curved portion is curved from the base end side to the tip end side toward the side where the base portion is located with respect to the second plane.

4. 3. The catheter according to claim 1, wherein the third curved portion is curved from the base end side to the tip end side in a direction opposite to the side on which the base portion is located with respect to the second plane.

5. The catheter according to any one of claims 1 to 4, characterized in that the direction in which the second curved portion curves is counterclockwise from the base end to the tip when the catheter is viewed from the tip side parallel to the extension direction of the base portion.

6. The catheter according to any one of claims 1 to 4, characterized in that the direction in which the second curved portion curves is clockwise from the base end to the tip when the catheter is viewed from the tip side parallel to the extension direction of the base portion.

7. The catheter according to any one of claims 1 to 6, characterized in that the minimum radius of curvature of the second curved portion is smaller than the minimum radius of curvature of the first curved portion, and the minimum radius of curvature of the third curved portion is smaller than the minimum radius of curvature of the second curved portion.

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