catheter

Abstract

[Problem] To provide a catheter with excellent operability and a method for engaging the catheter. [Solution] A hepatic artery catheter (1) that is introduced from a patient's arm and has a tubular body (2), wherein the tubular body (2) has an inner layer (31), an outer layer (32), and a reinforcing body (33) embedded in the tubular body (2), the tubular body (2) has an approximately linear main body part (23) and a shaped part (24) that is shaped to curve substantially on the same plane, the shaped part (24) has a first curved part (25) that defines a first angle (θ4) further on the tip end side than the main body part (23), a second curved part (26) that defines a second angle (θ5) further on the tip end side than the first curved part (25) and that is curved toward the same side as the first curved part (25), a third curved part (27) that defines a third angle (θ3) further on the tip end side than the second curved part (26) and that is curved toward the opposite side from the second curved part (26), and a distal tip end (28) that is disposed further on the tip end side than the third curved part (27), and there is a point where there is a change in physical characteristics between the base end-side end (25A) of the first curved part (25) and the tip end-side end (26A) of the second curved part (26).

Description

[Technical field]

[0001] The present invention relates to a catheter that is inserted into a living lumen. To Regarding. [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] In recent years, a procedure using TRI (Trans Radial Intervention) to insert a catheter through the radial artery in the wrist has become widespread (see, for example, Patent Documents 1 and 2). Introducing a catheter through an artery in the arm has the effect of reducing the physical burden on the patient and hastening discharge from hospital.

[0004] When there is a lesion in the liver, a treatment may be performed in which an embolic agent or medicine 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 location. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] European Patent No. 3013404 [Patent Document 2] International Publication No. 2015 / 146408 Summary of the Invention [Problem to be solved by the invention]

[0006] A guiding catheter for the hepatic artery introduced from an artery in the arm may be, for example, a guiding catheter for the coronary artery. However, the coronary artery and the hepatic artery have different shapes, making it difficult to operate. This is also true when using the catheter for an artery other than the hepatic artery.

[0007] A guiding catheter introduced from an artery in the arm is preferable for easy access to the descending aorta from the subclavian artery. Furthermore, the guiding catheter is preferable for providing a backup force to medical devices such as a treatment catheter and a guide wire, so as to reduce the reaction caused by the insertion of the treatment catheter and the guide wire, and to hold the treatment catheter in a desired position.

[0008] The present invention has been made to solve the above-mentioned problems, and provides a catheter having excellent operability. Le The purpose is to provide. [Means for solving the problem]

[0009] In order to solve the above problems, one aspect of the present invention is a catheter for a hepatic artery that is introduced from a patient's arm, the catheter having a tubular body that is positioned and communicated on substantially the same plane from a base end to a tip end, the tubular body having an inner layer, an outer layer, and a reinforcing body embedded in the tubular body, the tubular body having a substantially straight main body portion and a shaped portion that is bent and shaped on substantially the same plane, the shaped portion having a first bent portion that defines a first corner distal to the main body portion, a second bent portion that defines a second corner distal to the first bent portion and bends to the same side as the first bent portion, a third bent portion that defines a third corner distal to the second bent portion and bends to the opposite side to the second bent portion, and a most distal portion that is disposed distal to the third bent portion, The first bent portion and the second bent portion are connected to each other without sandwiching a linear portion, but sandwiching a portion that bends in the same direction as the first bent portion and the second bent portion with a radius of curvature larger than the radius of curvature of the first bent portion and the radius of curvature of the second bent portion, Between the base end of the first bent portion and the tip end of the second bent portion Bending stiffness decreases toward the tip It is characterized by having a point where physical properties change. Effect of the Invention

[0010] In the catheter configured as described above, the physical property change point is disposed between the base end side end of the first bent portion and the tip end side end of the second bent portion, so that the strong first bent portion comes into contact with the descending aorta, and the position of the shaped portion of the catheter is stabilized. The second bent portion, which is at least partially flexible, engages well with the celiac artery, and the third bent portion, which is flexible and disposed on the tip side of the physical property change point, is bent in the opposite direction to the second bent portion, so that the most distal portion is easily oriented toward the common hepatic artery. Therefore, the catheter can provide a good backup force to other medical devices inserted inside. In addition, the shaped portion in which the physical property change point is provided is more likely to firmly maintain the shape on the base end side of the physical property change point, so that the catheter can easily access the descending aorta. Therefore, the operability of the catheter is improved.

[0011] The physical property change point may be disposed at the first bent portion. This allows the distal end of the catheter to be stably directed toward the celiac artery by bending the strong first bent portion, and allows the flexible second bent portion disposed distal to the physical property change point to deform to fit the celiac artery and engage deeply. Therefore, this catheter can provide good backup force to other medical devices inserted inside. In addition, since the second bent portion is flexible, the burden on the blood vessel wall with which it comes into contact can be reduced.

[0012] The physical property change point may be disposed at the second bent portion, which increases the strength of the first bent portion and the second bent portion, thereby expanding the range in which the shape of the shaped portion can be firmly maintained, and facilitating access of the catheter from the subclavian artery to the descending aorta.

[0013] The physical property change point may be disposed between the first bent portion and the second bent portion. This allows the distal end of the catheter to be stably directed toward the celiac artery by bending the strong first bent portion, and the flexible second bent portion disposed distal to the physical property change point can be deformed to conform to the celiac artery and deeply engaged. Therefore, the catheter can provide a good backup force to other medical devices inserted inside. In addition, since the second bent portion is flexible, the burden on the blood vessel wall with which it comes into contact can be reduced. Furthermore, since the overall strength of the first bent portion is improved, the range in which the shape of the shaped portion can be firmly maintained is wide, and the catheter can easily access the descending aorta from the subclavian artery.

[0014] The physical property change point may be an end portion of the reinforcing body. Since the reinforcing body increases the hardness, the physical property change point can be easily provided without changing the resin of the inner layer or outer layer.

[0015] When the second bent portion is placed in contact with the vascular wall of the celiac artery, the most distal portion may face the common hepatic artery, and the first bent portion may contact the wall surface of the descending aorta on the opposite side to the celiac artery. This allows the second bent portion to be satisfactorily engaged with the celiac artery while the strong first bent portion is in stable contact with the vascular wall of the descending aorta on the opposite side to the celiac artery.

[0016] The first bent portion extends from the tip of the main body toward the tip and is bent in one direction. ,before The second bent portion and the third bent portion may be connected directly or with a linear portion interposed therebetween, and the most distal portion may extend in a distal direction from a tip of the third bent portion.

[0017] The catheter may have a lubricating coating that covers an area of ​​400 mm or less from the distal opening of the tubular body in the proximal direction along the axis. The lubricating coating may cover an area of ​​200 mm or less from the distal opening of the tubular body in the proximal direction along the axis. The lubricating coating may cover an area of ​​150 mm from the distal opening of the tubular body in the proximal direction along the axis. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram showing placement of a catheter within a blood vessel. [Diagram 2] FIG. 2 is a plan view showing the tip portion of the catheter according to the embodiment. [Diagram 3] FIG. 2 is a plan view showing the tip portion of the catheter according to the embodiment. [Figure 4] FIG. 2 is a cross-sectional view showing a portion of a catheter according to an embodiment. [Diagram 5] FIG. 2 is a plan view showing a three-point bending test machine. [Figure 6] FIG. 1 is a schematic diagram showing a catheter inserted into the descending aorta. [Figure 7] FIG. 2 is a schematic diagram showing a state in which a catheter is inserted into the celiac artery. [Figure 8] 1A and 1B are plan views showing the positions of the ends of the reinforcing body, which are the points at which the physical properties change, in which (A) is Modification 1 and (B) is Modification 2. FIG. [Figure 9] FIG. 1 is an overall view of a catheter according to a first embodiment, with a portion of the catheter omitted in the longitudinal direction. [Figure 10] FIG. 1 is an overall view of a catheter according to a second embodiment, with a portion of the catheter omitted in the longitudinal direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that dimensions in the drawings may be exaggerated and may differ from actual dimensions for convenience of explanation. In addition, in this specification and the drawings, components having substantially the same functions are given the same reference numerals to avoid duplicated explanation. In this specification, the side inserted into a lumen is referred to as the "distal side" and the side operated is referred to as the "base side".

[0020] The catheter 1 according to this embodiment is a catheter for reaching the common hepatic artery 105, as shown in Figs. 1 and 7. The catheter 1 is introduced into a blood vessel from an artery 100 (e.g., radial artery) in the patient's arm and directed toward the vicinity of the hepatic artery. The catheter 1 may be a so-called guiding catheter, an angiography catheter, a guidewire support catheter, or a microcatheter. The catheter 1 may also be a combination of a guiding catheter and a microcatheter that is longer than the guiding catheter and is inserted into the inner tube of the guiding catheter.

[0021] As shown in FIGS. 1 to 3, 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.

[0022] 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.

[0023] 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 guide wire 6, a therapeutic catheter 7, etc. The hub 5 can also be used to inject various liquids such as an X-ray contrast agent, a medicinal liquid, and saline solution.

[0024] The kink-resistant protector 4 is made of an elastic material. The kink-resistant protector 4 covers the portion where the tubular body 2 and the hub 5 are connected. In this way, the kink-resistant protector 4 prevents bending or kinking of the tubular body 2 in the vicinity of the portion. Furthermore, a flexible kink-resistant tube 8 having an outer diameter larger than that of the tubular body 2 and inserted into the base end side of the tubular body 2 and fixed to the hub 5 may be provided between the kink-resistant protector 4 and the tubular body 2, or the kink-resistant protector 4 may be omitted and only the kink-resistant tube 8 may be provided.

[0025] The tubular body 2 will be described in detail. As shown in Fig. 4, the tubular body 2 is composed of a plurality of layers, including an inner layer 31 that forms the inner surface of the lumen 21, an outer layer 32 that is formed on the outside of the inner layer 31, and a reinforcing body 33 that is embedded in the tubular body 2. The resins of the inner layer 31 and the outer layer 32 may be the same, or may differ in color, hardness, contrast medium, etc.

[0026] The inner layer 31 has a lumen 21 formed therein. The constituent material of the inner layer 31 may be a thermoplastic resin, a thermosetting resin, or the like, and is preferably a fluorine-based resin such as polytetrafluoroethylene (PTFE), a low-friction material such as high-density polyethylene (HDPE), or the like, or may be any of various thermoplastic elastomers such as polyurethane, polyester, polyamide, polybutadiene, trans-polyisoprene, fluororubber, and chlorinated polyethylene.

[0027] The outer layer 32 is a tubular member that covers the outer periphery of the inner layer 31. The outer layer 32 forms the outer surface on the radially outer side of the tubular body 2. Examples of materials constituting the outer layer 32 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. The outer layer 32 may contain an X-ray contrast material.

[0028] The reinforcing member 33 is embedded in the tubular body 2. That is, the reinforcing member 33 is disposed between the inner surface and the outer surface of the tubular body 2. The reinforcing member 33 is formed by braiding a plurality of wires 34 into a tubular shape with gaps therebetween. The reinforcing member 33 may be formed by winding the wires 34 while changing the winding direction, such as horizontal winding in the same direction or clockwise / counterclockwise winding, and the winding pitch, lattice distance, inclination angle with respect to the circumferential direction, etc., may be changed depending on the position, and the configuration is not particularly limited.

[0029] The wire diameter (diameter) of the wire 34 of the reinforcing member 33 is not particularly limited, but is, for example, 0.04 to 0.05 mm. The cross-sectional shape of the wire 34 is not particularly limited, but is, for example, a circle, an ellipse, a rectangle, or the like.

[0030] The wires 34 used in the reinforcing member 33 may be metal wires such as stainless steel, platinum (Pt) or tungsten (W), resin fibers, carbon fibers, glass fibers, or the like, or a plurality of these wires 34 may be used in combination.

[0031] As shown in Figs. 2 and 3, the tubular body 2, which includes the inner layer 31, the outer layer 32, and the reinforcing body 33, has a substantially straight main body portion 23 and a shaped shaped portion 24. The shaped portion 24 is curved in substantially the same plane. The shaped portion 24 may include a linear portion. The shaped portion 24 has a first bent portion 25, a second bent portion 26, a third bent portion 27, and a most distal portion 28. The first bent portion 25 extends from a first intermediate point P1 located at the distal end of the main body portion 23 toward the distal end and is bent within the plane. The second bent portion 26 extends from a second intermediate point P2 located at the distal end of the first bent portion 25 toward the distal end and is bent in the same direction as the first bent portion 25 within the plane. The second intermediate point P2 is the portion between the first bent portion 25 and the second bent portion 26 that has the largest radius of curvature. When the portion having the largest radius of curvature between the first bent portion 25 and the second bent portion 26 has a predetermined range along the center line of the tubular body 2, the second intermediate point P2 can be defined as, for example, the center along the center line of the range. A linear portion may be provided in a predetermined range (length) between the first bent portion 25 and the second bent portion 26. The third bent portion 27 extends from the third intermediate point P3 located at the tip of the second bent portion 26 toward the tip direction, and bends in the opposite direction to the second bent portion 26 in the plane. The third intermediate point P3 is the portion having the largest radius of curvature between the second bent portion 26 and the third bent portion 27. When the portion having the largest radius of curvature between the second bent portion 26 and the third bent portion 27 has a predetermined range along the center line of the tubular body 2, the third intermediate point P3 can be defined as, for example, the center along the center line of the range. A linear portion may be provided over a predetermined range (length) between the second bent portion 26 and the third bent portion 27. The most distal portion 28 extends linearly in the distal direction from a fourth intermediate point P4 located at the tip of the third bent portion 27. The fourth intermediate point P4 is located at the base end of the approximately linear most distal portion 28. Note that being curved in substantially the same plane may include a case where the tip of the catheter 1 protrudes slightly from the plane to an extent that the same practical effect can be achieved, in addition to being curved within the same plane.

[0032] An axis passing through the center line of the main body 23 is defined as the first axis A. A tangent or straight line to the center line of the tubular body 2 at the second intermediate point P2 is defined as the second axis B. A tangent to the center line of the tubular body 2 at the third intermediate point P3 is defined as the third axis C. An axis passing through the center line of the most distal end portion 28 is defined as the fourth axis D.

[0033] The angle that the second axis B makes with respect to the first axis A on the tip side is defined as a first angle θ4. The first angle θ4 is the amount of change in the direction of the center line of the tubular body 2 at the first bent portion 25. That is, the first bent portion 25 defines the first angle θ4. The radius of curvature of the first bent portion 25 may be constant at the first bent portion 25, but may also vary. At the first bent portion 25, the first minimum radius of curvature R1 at the portion with the smallest radius of curvature (the portion that is bent most sharply) is preferably 10 to 80 mm, more preferably 15 to 60 mm, and even more preferably 20 to 55 mm. In the example of FIG. 2, the first minimum radius of curvature R1 is 30 mm. The radius of curvature at the second intermediate point P2 is 50 mm. The first angle θ4 is preferably 10 to 120°, more preferably 45 to 90°, and even more preferably 60 to 80°. In the example of FIG. 2, the first angle θ4 is 70°.

[0034] The angle that the third axis C makes with respect to the second axis B on the tip side is defined as the second angle θ5. The second angle θ5 is the amount of change in the direction of the center line of the tubular body 2 at the second bent portion 26. That is, the second bent portion 26 defines the second angle θ5. The radius of curvature of the second bent portion 26 may be constant or may vary. In the second bent portion 26, the second minimum radius of curvature R2 of the portion with the smallest radius of curvature (the portion that is most sharply bent) is preferably 5 to 15 mm, more preferably 7 to 12 mm, and even more preferably 8 to 11 mm. In the example of FIG. 2, the second minimum radius of curvature R2 is 9 mm. The second angle θ5 is preferably 10 to 170°, more preferably 55 to 100°, and even more preferably 70 to 90°. In the example of FIG. 2, the second angle θ5 is 80°. The second minimum radius of curvature R2 is smaller than the first minimum radius of curvature R1.

[0035] The angle that the fourth axis D makes with respect to the third axis C on the distal end side is defined as a third angle θ3. The third angle θ3 is the amount of change in the direction of the center line of the tubular body 2 at the third bent portion 27. That is, the third bent portion 27 defines the third angle θ3. The radius of curvature of the third bent portion 27 may be constant or may vary. In the third bent portion 27, the third minimum radius of curvature R3 of the portion with the smallest radius of curvature (the portion that is most sharply bent) is preferably 1 to 9 mm, more preferably 2 to 8 mm, and even more preferably 4 to 7 mm. In the example of FIG. 2, the third minimum radius of curvature R3 is 5 mm. The third angle θ3 is preferably more than 0° and not more than 90°, more preferably 20 to 70°, and even more preferably 30 to 60°. In the example of FIG. 2, the third angle θ3 is 45°.

[0036] The intersection of the first axis A and the second axis B is defined as the first intersection E1, the intersection of the second axis B and the third axis C is defined as the second intersection E2, and the intersection of the third axis C and the fourth axis D is defined as the third intersection E3.

[0037] The distance L1 between the first intersection E1 and the second intersection E2 is preferably 5 to 100 mm, more preferably 20 to 60 mm, and further preferably 30 to 50 mm. In the example of Fig. 2, the distance L1 is 34 mm.

[0038] The distance L2 between the second intersection point E2 and the third intersection point E3 is preferably 1 to 80 mm, more preferably 5 to 50 mm, and further preferably 10 to 20 mm. 0 In the example of FIG. 2, the distance L2 is 12 mm.

[0039] The distance L3 between the third intersection point E3 and the most distal end of the most distal portion 28 is preferably 0.1 to 60 mm, more preferably 1 to 40 mm, and further preferably 2 to 30 mm. In the example of Fig. 2, the distance L3 is 3.5 mm.

[0040] The length L4 along the center line of the most distal end portion 28 is preferably 0.1 to 50 mm, more preferably 0.5 to 30 mm, and further preferably 1 to 20 mm. In the example of Fig. 2, the length L4 is 1.4 mm.

[0041] In the second bent portion 26, the portion with the smallest radius of curvature (the portion that is bent the sharpest) is defined as the second bent point P5. In the case where the portion with the smallest radius of curvature in the second bent portion 26 has a predetermined range along the center line of the tubular body 2, the second bent point P5 can be defined as, for example, the center along the center line of that range. An axis passing through the second bent point P5 and the first intermediate point P1 located at the tip of the main body portion 23 is defined as the fifth axis F. An angle that the fifth axis F forms with the first axis A on the tip side is defined as the first inclination angle θ1. The first inclination angle is preferably 10 to 110°, more preferably 34 to 63°, and further preferably 40 to 50°. In the example of FIG. 2, the first inclination angle θ1 is 46°. The larger the first inclination angle θ1, the larger the bending of the tubular body 2.

[0042] The second inclination angle θ2 is an angle range in which the second bent portion 26 has the second minimum radius of curvature R2. That is, the second bent portion 26 has the second minimum radius of curvature R2 in the range of the second inclination angle θ2. The second inclination angle θ2 is preferably 5 to 120°, more preferably 10 to 90°, and further preferably 38 to 80°. In the example of FIG. 2, the second inclination angle θ2 is 73°.

[0043] The angle that the fourth axis D forms with respect to the first axis A on the tip side is defined as a third inclination angle θ6. The third inclination angle θ6 is the angle that the most distal end portion 28 forms with respect to the main body portion 23. The third inclination angle θ6 is preferably 0 to 240° or less, more preferably 80 to 150°, and further preferably 90 to 120°. In the example of FIG. 2, the third inclination angle θ6 is 105°.

[0044] Alternatively, the radius of curvature of the second intermediate point P2 may be 40 mm or more, more preferably 50 mm or more, and further preferably, the second intermediate point P2 may be a substantially straight line. Furthermore, the direction of the straight line G connecting the second intermediate point P2 and the second bending point P5 from the second intermediate point P2 to the second bending point P5 is a direction away from the main body 23, and the hub 21 is located in the extension direction of the main body 23. 5 In other words, the angle θ7 formed by the second intermediate point P2, the intersection point E4 between the straight line G and the first central axis A, and the first intermediate point P1 is an obtuse angle. In this case, the catheter 1 can be prevented from entering the left gastric artery 106 or the splenic artery 107. In the example of FIG. 2, θ7 is 102°.

[0045] A reinforcing member 33 is embedded in the tubular body 2 within a range from the base end to a predetermined position in the tip direction. An end 35 on the tip side of the reinforcing member 33 is disposed between an end 25A on the base end side of the first bent portion 25 and an end 26A on the tip side of the second bent portion 26. In this embodiment, the end 35 on the tip side of the reinforcing member 33 is disposed between the first bent portion 25 and the second bent portion 26.

[0046] The catheter 1 may be coated with a lubricating coating from the tip opening 22 along the axis toward the base end. The lubricating coating may be applied over the entire length, for example, over a range of at least 400 mm or less, more preferably 200 mm or less, from the tip opening 22 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.

[0047] 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, even more preferably 1000 to 1500 mm, and even more preferably may be selected from 1100 mm, 1200 mm, 1250 mm, and 1300 mm depending on the body size or for the reason of inserting from the distal radial artery or the snuffbox radial artery. 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. For example, when the catheter 1 is introduced from the brachial artery of a small woman, it is preferable that the effective length of the tubular body 2 is relatively short. When the catheter 1 is introduced from the distal radial artery of a large man, it is preferable that the effective length of the tubular body 2 is relatively long. The effective length is the length of a portion that can be inserted into a blood vessel, a sheath, etc. 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.

[0048] The length L5 along the central axis of the tubular body 2 from the end 25A on the base end side of the first bent portion 25 of the tubular body 2 to the end 35 on the tip side of the reinforcing member 33 is preferably 1 to 75 mm, more preferably 20 to 45 mm. The length L6 along the central axis of the tubular body 2 from the end 35 on the tip side of the reinforcing member 33 of the tubular body 2 to the tip of the tubular body 2 is preferably 1 to 50 mm, more preferably 20 to 30 mm. The length along the central axis of the tubular body 2 corresponds to the length when the tubular body 2 is deformed into a straight line. The length L7 from the end 25A on the base end side of the first bent portion 25 of the tubular body 2 to the tip of the tubular body 2 is the sum of the above-mentioned lengths L5 and L6, and is preferably 40 to 75 mm, more preferably 50 to 75 mm.

[0049] The ratio of L6 / L7 is preferably 1 to 100%, more preferably 10 to 60%, and further preferably 10 to 40%. Alternatively, the ratio of L6 / L5 is preferably 1 to 200%, and more preferably 10% or more and less than 70%. As an example, L5 is 37 mm, L6 is 23 mm, L7 is 60 mm, L6 / L7 is 38%, and L6 / L5 is 62%.

[0050] The tubular body 2 has a flexible portion 36 where the reinforcing body 33 is not provided, on the distal side of the portion where the reinforcing body 33 is embedded. The catheter 1 is provided with the flexible portion 36, so that the catheter 1 can move in a bent or branched blood vessel without damaging the blood vessel. The length of the flexible portion 36 is equal to the above-mentioned length L6. In the case of a 4Fr catheter 1, the length L6 of the flexible portion 36 is 23 mm. In the case of a 5Fr catheter 1, the length L6 of the flexible portion 36 is 23 mm. The flexible portion 36 has lower bending characteristics than the portion where the reinforcing body 33 is provided. The bending characteristics may be a bending modulus, a measured value of a load or a stress in a three-point bending test, or the like. The bending modulus of at least a portion of the tubular body 2 is preferably 2 to 25 MPa, more preferably 4 to 20 MPa, even more preferably 7 to 13 MPa, and even more preferably 9 to 10 MPa. The load in a three-point bending test of the portion of the tubular body 2 where the reinforcing member 33 is provided is preferably 20 to 250 gf, and more preferably 40 to 120 gf. When the outer diameter of the catheter 1 is 4 Fr, the bending characteristic (load) is preferably 40 gf or more. When the outer diameter of the catheter 1 is 5 Fr, the bending characteristic (load) is preferably 80 gf or more.

[0051] An example of bending characteristic measurement by a three-point bending test is shown in Figure 5. The measurement conditions are, for example, room temperature of 25°C, distance S between the supports of support stand 71 of 25.4 mm (1 inch), test speed of indenter 72 pressing the center position between the supports from the opposite side of the support stand 71 is 5 mm / min, and pressing amount T of indenter 72 is 2 mm. Indenter width W1 is 1.0 mm, and indenter curvature radius r1 is 0.5 mm. Support width W2 of each support 73 of support stand 71 is 4.0 mm, and curvature radius r2 of each support 73 is 0.5 mm. The pressing load measured under these conditions can be used as bending characteristic.

[0052] A distal tip that is more flexible than the proximal end side may be disposed at the distal end of the tubular body 2. The distal tip is made of a flexible material such as a rubber material.

[0053] 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.

[0054] Next, a method of using the catheter 1 according to this embodiment will be described.

[0055] As shown in FIG. 1, the catheter 1 is inserted into a blood vessel from an artery 100 in an arm and engaged with a celiac artery 104. The artery 100 in the arm into which the catheter 1 is introduced may be, for example, a distal radial artery, a conventional radial artery, an ulnar artery, a distal ulnar artery, a brachial artery, or a snuff box radial artery. Here, an example will be described in which the catheter 1 is inserted into an artery in the left arm. The catheter 1 may also be inserted into an artery in the right arm.

[0056] In the procedure, the surgeon inserts the guidewire 6 into the arm artery 100. 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.

[0057] As shown in FIG. 6, the guide wire 6 and the catheter 1 pass through the subclavian artery 101 and advance to the aortic arch 102. At the site where the subclavian artery 101 connects to the aortic arch 102, the catheter 1 needs to bend significantly to move toward 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 bent shape. The surgeon can use the bending of the shaped portion 24 to advance the tip of the catheter 1 from the aortic arch 102 toward the descending aorta 103. Since the shaped portion 24 is provided with the reinforcing body 33 and thus easily maintains its shape, the catheter 1 can easily access the descending aorta 103 from the subclavian artery 101. After this, the surgeon protrudes the guide wire 6 from the catheter 1. This allows the guide wire 6 to easily advance toward the descending aorta 103. Next, the surgeon pushes the catheter 1 along the guide wire 6. This allows the catheter 1 to easily advance from the aortic arch 102 to the descending aorta 103. The catheter 1 moves down the descending aorta 103 to the lower side X (the side closer to the lower limbs) and reaches the vicinity of the celiac artery 104.

[0058] After the guidewire 6 and the catheter 1 reach the vicinity of the entrance of the celiac artery 104, the operator retracts the guidewire 6 to accommodate the guidewire 6 in the lumen 21 of the catheter 1. As a result, as shown in FIG. 7, the shaped portion 24 of the catheter 1 is restored to its original bent shape. The operator can insert the tip of the catheter 1 into the celiac artery 104 by utilizing the bending of the shaped portion 24. The celiac artery 104 extends generally anteriorly Z (abdominal 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 inferior side X (the side closer to the lower limbs). The left gastric artery 106 and the splenic artery 107 generally extend from the celiac artery 104 to the superior side Y (the side closer to the head). The second bent portion 26 of the catheter 1 contacts the vascular wall of the celiac artery 104, and the first bent portion 25 contacts the vascular wall of the descending aorta 103 on the opposite side to the entrance of the celiac artery 104. The second bent portion 26 contacts the vascular wall of the lower side X of the celiac artery 104. This causes the second bent portion 26 of the catheter 1 to engage with the celiac artery 104. In this state, the third bent portion 27 is bent in the opposite direction to the first bent portion 25 and the second bent portion 26. Therefore, the tip of the catheter 1 is likely to be directed toward the common hepatic artery 105 extending from the celiac artery 104 to the lower side X. The third bent portion 27 and / or the tip portion 28 may, but need not, contact the vascular wall of the common hepatic artery 105.

[0059] In the catheter 1, the tip end 35 of the reinforcing member 33, which is the point where the physical properties change, is located at a predetermined distance (for example, 20 to 30 mm) from the tip, and the flexible portion 36 on the tip side of the reinforcing member 33 contacts the wall surface of the celiac artery 104, thereby stabilizing the position. 3Since the catheter 1 according to the present embodiment is for use in the hepatic artery and has at least the second bent portion 26 inserted into the celiac artery 104, the structure and the method of engagement are different from those of the guiding catheter for the coronary artery. Unlike Jacky-type and Sarah-type catheters, which have a sharp bend in the bent portion and protrude from the catheter, the first bent portion 25 is smoothly curved, and can smoothly contact the vascular wall, thereby reducing the burden on the blood vessel.

[0060] Furthermore, a conventional catheter that is inserted from the femoral artery and engages with the celiac artery 104 is disposed in a substantially straight line from the femoral artery to the celiac artery 104, and therefore can exert a backup force even without the reinforcing member 33 in the shaped portion. However, when this conventional catheter is introduced from an artery in the arm, there is a risk of "prolapse" occurring, in which a part of the catheter is deflected toward the ascending aorta, opposite the descending aorta 103, due to the injection of contrast medium or the operation of the microcatheter.

[0061] In order to prevent prolapse, it is preferable that the end 35 (physical property change point) of the reinforcing body 33 of the catheter 1 is located between the end 25A on the base end side of the first bent portion 25 and the end 26A on the tip side of the second bent portion 26. The bending rigidity of the catheter 1 changes significantly at the physical property change point, decreasing toward the tip side. body In addition to the end 35 of 33, the hardness of the resin of the outer layer 32 and / or the inner layer 31 may be changed so as to become softer toward the tip side, or the catheter 1 may be tapered toward the tip side.

[0062] Furthermore, in order to increase the repulsive force of the catheter 1, a reinforcement body The end 35 of 33 may be located near or coincident with the second midpoint P2 where the radius of curvature is maximum.

[0063] 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 the lower side X 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 face the upper side Y. 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 and the guide wire 6. 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.

[0064] As described above, the catheter 1 according to this embodiment is a catheter 1 for the hepatic artery introduced from the arm of a patient, and has a tubular body 2 that communicates from the base end to the tip end, the tubular body 2 has an inner layer 31, an outer layer 32, and a reinforcing body 33 embedded in the tubular body 2, the tubular body 2 has a substantially straight main body portion 23 and a shaped portion 24 that is bent and shaped substantially on the same plane, and the shaped portion 24 defines a first angle θ4 on the tip side of the main body portion 23. a first bent portion 25 that defines a second angle θ5 further distal than the first bent portion 25 and bends to the same side as the first bent portion 25; a third bent portion 27 that defines a third angle θ3 further distal than the second bent portion 26 and bends to the opposite side to the second bent portion 26; and a most distal portion 28 that is arranged more distal than the third bent portion 27, and a physical property change point is between an end 25A on the base end side of the first bent portion 25 and an end 26A on the distal side of the second bent portion 26.

[0065] In the catheter 1 configured as described above, the physical property change point is disposed between the end 25A on the base end side of the first bent portion 25 and the end 26A on the tip end side of the second bent portion 26, so that the first bent portion 25, which has high strength, comes into contact with the descending aorta 103, and the position of the shaped portion 24 of the catheter 1 is stabilized. The second bent portion 26, which is at least partially flexible, engages well with the celiac artery 104, and the third bent portion 27, which is flexible and disposed on the tip side of the physical property change point, is bent in the opposite direction to the second bent portion 26, so that the most distal portion 28 is easily oriented toward the common hepatic artery 105. Therefore, the catheter 1 can provide a good backup force to other medical devices, such as the treatment catheter 7 and the guidewire 6, which are inserted inside. In addition, the shaped portion 24, in which the physical property change point is provided, is easily able to firmly maintain the shape on the base end side of the physical property change point, so that the catheter 1 can easily access the descending aorta 103 from the subclavian artery 101 (left subclavian artery or right subclavian artery) of the catheter 1. Therefore, the operability of the catheter 1 is improved.

[0066] In addition, the physical property change point is disposed between the first bent portion 25 and the second bent portion 26. As a result, the tip side of the catheter 1 can be stably directed toward the celiac artery 104 by bending the first bent portion 25 having high strength, and the flexible second bent portion 26 disposed on the tip side of the physical property change point can be deformed to match the celiac artery 104 and deeply engaged (deep engagement). Therefore, the catheter 1 can provide a good backup force to other medical devices such as the treatment catheter 7 and the guide wire 6 inserted therein. In addition, since the second bent portion 26 is flexible, the burden on the blood vessel wall with which it comes into contact can be reduced. Furthermore, since the overall strength of the first bent portion 25 is improved, the range in which the shape of the shaped portion 24 can be firmly maintained is wide, and the catheter 1 can easily access the descending aorta 103 from the subclavian artery 101.

[0067] The physical property change point is the end 35 of the reinforcing body 33. Since the presence of the reinforcing body 33 makes the material harder, the physical property change point can be easily provided without changing the resin of the inner layer 31 or the outer layer 32.

[0068] Furthermore, when the second bent portion 26 is placed in contact with the vascular wall of the celiac artery 104, the most distal portion 28 faces the common hepatic artery 105, and the first bent portion 25 contacts the wall surface of the descending aorta 103 on the side opposite the celiac artery 104. This allows the second bent portion 26 to be satisfactorily engaged with the celiac artery 104 while the strong first bent portion 25 is in stable contact with the vascular wall of the descending aorta 103 on the side opposite the celiac artery 104.

[0069] The present invention also includes a method for engaging the catheter 1. The method for engaging the catheter 1 includes the steps of inserting the above-mentioned catheter 1 having a physical property change point between the end 25A on the base end side of the first bent portion 25 and the end 26A on the tip end side of the second bent portion 26 into an artery in an arm (e.g., the radial artery 100), advancing the shaped portion 24 of the catheter 1 into a main artery accessible from the artery in the arm (e.g., the descending aorta 103), advancing the shaped portion 24 into a first blood vessel (e.g., the celiac artery 104) connected in a direction intersecting with the long axis of the main artery, and bringing the second bent portion 26 into contact with the vascular wall of the first blood vessel and bringing the first bent portion 25 into contact with the vascular wall of the main artery opposite to the first blood vessel, thereby directing the most distal portion 28 toward a second blood vessel selected from at least two blood vessels branching into one another on the peripheral side of the first blood vessel.

[0070] The engagement method of the catheter 1 configured as described above can stabilize the position of the shaped portion 24 of the catheter 1 by bringing the strong first bent portion 25 into contact with the main artery using the reinforcing member 33. Then, the second bent portion 26, at least a part of which is flexible, can be satisfactorily engaged with the first blood vessel, and the most distal portion 28 can be directed toward the second blood vessel. This allows the surgeon to easily insert another medical device into the second blood vessel using the catheter 1 as a guide.

[0071] 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 designed appropriately within the range of the above-mentioned various angles, dimensions, etc. For example, as in the first modified example shown in FIG. 8(A), the end 35 of the reinforcing body 33, which is the point where the physical properties change, may be disposed at the first bent portion 25. This allows the distal end side of the catheter 1 to be stably directed toward the celiac artery 104 by bending the first bent portion 25, which has the reinforcing body 33 and is strong, and the flexible second bent portion 26, which is disposed on the distal side of the reinforcing body 33, can be deformed to match the celiac artery 104 and deeply engaged. Therefore, the present catheter 1 can provide a good backup force to other medical devices inserted inside. In addition, since the second bent portion 26 is flexible, the burden on the blood vessel wall that comes into contact with it can be reduced.

[0072] 8(B), the end 35 of the reinforcing member 33, which is the point at which the physical properties change, may be disposed at the second bent portion 26. This improves the strength of the first bent portion 25 and the second bent portion 26, widening the range in which the shape of the shaped portion 24 can be firmly maintained, and facilitating access of the catheter 1 from the subclavian artery 101 to the descending aorta 103.

[0073] Specific examples of the present invention will now be described in detail. EXAMPLES

[0074] A catheter 1 was produced that was provided with a kink-resistant tube 8 shown in Figure 9. The parameters of the catheter 1 were as follows. Effective length: 1250mm Outer diameter: 1.4mm (4Fr) Inner diameter (lumen diameter): 1.1 mm Cross-sectional structure: Laminate of inner layer, reinforcing body, and outer layer Reinforcement wire diameter and structure: 0.04 mm, double mesh wire Length of lubricating tip coat: 150mm θ1:47° θ2:77° θ3:45° θ4:70° θ5:85° θ6:102° θ7:97° L1: 34mm L2: 12mm L3: 3.5 mm L4: 1.4 mm L5: 37mm L6: 23mm L7: 60mm R1: 30mm R1: 30mm R2: 9mm R3: 5mm Curvature radius at P2: 50mm EXAMPLES

[0075] A catheter 1 shown in Figure 10 was produced. The parameters of the catheter 1 were as follows. Effective length: 1250mm Outer diameter: 1.7mm (5Fr) Inner diameter (lumen diameter): 1.2 mm Cross-sectional structure: Laminate of inner layer, reinforcing body, and outer layer Reinforcing wire diameter and structure: 0.05mm, double mesh wire Length of lubricating tip coat: 150mm θ1:44° θ2:76° θ3:20° θ4:70° θ5:81° θ6: 129° θ7:99° L1: 34mm L2: 12mm L3: 3.5 mm L4: 1.4 mm L5: 37mm L6: 23mm L7: 60mm R1: 30mm R1: 30mm R2: 9mm R3: 5mm Curvature radius at P2: 50mm

[0076] It should be noted that 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.

[0077] This application is based on Japanese Patent Application No. 2020-131419 filed on August 3, 2020 and Japanese Patent Application No. 2020-197871 filed on November 30, 2020, the disclosures of which are hereby incorporated by reference in their entirety. [Explanation of symbols]

[0078] 1 Catheter 2 Tubular body 6 Guidewire 7 Therapeutic Catheters 8 Kink-resistant tube 21 Lumens 23 Main body 24 Shape part 25 1st bending part 26 2nd bending part 27 Third bend 28 Cutting edge section 31 Inner layer 32 Outer layer 33 Reinforcement 34 Wire rod 35 Reinforcement 36 Flexible section 100 Radial artery 101 Subclavian artery 102 Aortic Arch 103 Descending aorta 104 Celiac artery 105 Common hepatic artery 106 Left gastric artery 107 Splenic artery

Claims

1. A catheter for the hepatic artery introduced through a patient's arm, A tubular body is disposed on substantially the same plane from the base end to the tip end and communicates with the the tubular body having an inner layer, an outer layer and a reinforcing body embedded in the tubular body; The tubular body has a substantially straight main body portion and a shaped portion that is bent and shaped in substantially the same plane, The shape portion is a first bent portion defining a first corner on a tip side of the main body portion; a second bent portion that defines a second corner on a tip side of the first bent portion and bends toward the same side as the first bent portion; a third bent portion that defines a third corner on a tip side of the second bent portion and bends in an opposite direction to the second bent portion; a distal end portion disposed distally of the third bent portion, The first bent portion and the second bent portion are connected to each other without sandwiching a linear portion, but sandwiching a portion that bends in the same direction as the first bent portion and the second bent portion with a radius of curvature larger than the radius of curvature of the first bent portion and the radius of curvature of the second bent portion, A catheter characterized in that there is a physical property change point between a base end side end of the first bent portion and a tip end side end of the second bent portion, where bending rigidity decreases toward the tip side.

2. The catheter according to claim 1 , wherein the physical property change point is disposed at the first bent portion.

3. The catheter according to claim 1 , wherein the physical property change point is disposed at the second bent portion.

4. The catheter according to claim 1 , wherein the physical property change point is disposed between the first bent portion and the second bent portion.

5. The catheter according to any one of claims 1 to 4, wherein the physical property change point is an end portion of the reinforcing member.

6. 6. The catheter according to claim 1, wherein when the second bent portion is placed in contact with a vascular wall of the celiac artery, the most distal portion faces the common hepatic artery, and the first bent portion contacts a wall surface of the descending aorta on a side opposite to the celiac artery.

7. The first bent portion extends from a tip of the main body portion in a tip direction and bends in one direction, The second bent portion and the third bent portion are connected directly or via a linear portion, The catheter according to any one of claims 1 to 6, wherein the most distal portion extends in a distal direction from a tip of the third bent portion.

8. 8. The catheter according to claim 1, further comprising a lubricating coating covering an area of ​​400 mm or less from the tip opening of the tubular body along the axis toward the base end.

9. 9. The catheter according to claim 8, wherein the lubricating coating covers an area of ​​200 mm or less from the tip opening of the tubular body along the axis toward the base end.

10. 9. The catheter according to claim 8, wherein the lubricating coating covers an area of ​​150 mm from the tip opening of the tubular body along the axis toward the base end.

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