Catheter and method of engaging a catheter
By designing a catheter with inner and outer layers and reinforcement, and by utilizing multiple bends and points of change in physical properties, the problem of catheters being difficult to enter the hepatic artery was solved, achieving stable positioning of the catheter within the hepatic artery and improving operability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TERUMO KK
- Filing Date
- 2021-03-26
- Publication Date
- 2026-06-19
AI Technical Summary
In existing technologies, catheters inserted through an artery in the arm are difficult to effectively enter the hepatic artery, have poor operability, and are difficult to stably position at the target location, thus affecting the treatment effect.
A catheter has been designed with an inner layer, an outer layer, and a reinforcing body embedded in a tubular body. The tubular body has a generally straight main body and a curved part in the same plane, including a first curved part, a second curved part, and a third curved part. The catheter has a property change point set at a specific location to improve its operability and stability.
The catheter's high-strength first bend contacts the descending aorta, ensuring stable positioning of the shaped portion. The flexible second bend engages well with the celiac artery, improving the catheter's operability and support for other medical devices while reducing the burden on the blood vessel wall.
Smart Images
Figure CN116194171B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to catheters inserted into the lumen of a living organism, and methods for engaging the catheter with a blood vessel. Background Technology
[0002] Currently, interventional therapy is being promoted, which uses a long catheter inserted into a blood vessel through a hole in the skin to treat lesions in the heart, blood vessels, liver, brain, digestive organs, urinary organs, etc.
[0003] In recent years, the use of TRI (Trans Radial Intervention) to insert a catheter through the radial artery in the wrist for treatment has been widely adopted (see, for example, patent documents 1 and 2). By introducing a catheter through an artery in the arm, it has the advantages of reducing the physical burden on patients and speeding up hospital discharge.
[0004] In cases where there is a lesion in the liver, treatment is sometimes performed by inserting a therapeutic catheter near the hepatic artery to deliver embolic agents or medications to the lesion. When performing this treatment, a guiding catheter is desired to ensure that the therapeutic catheter can function effectively at the target location.
[0005] Existing technical documents
[0006] Patent documents
[0007] Patent Document 1: Description of European Patent No. 3013404
[0008] Patent Document 2: International Publication No. 2015 / 146408 Summary of the Invention
[0009] A guiding catheter for the hepatic artery is sometimes used, for example, a guiding catheter for the coronary artery. However, because the coronary artery and the hepatic artery have different shapes, it is difficult to operate. The same applies when using catheters for arteries other than the hepatic artery.
[0010] The guiding catheter inserted from an artery in the arm is preferably one that can easily enter the descending aorta from the subclavian artery. Furthermore, the guiding catheter is preferably one that applies support to medical devices such as therapeutic catheters or guidewires to mitigate the reaction force caused by the insertion of the therapeutic catheter or guidewire and to hold the therapeutic catheter in the desired position.
[0011] The present invention was made to solve the above-mentioned problems, with the aim of providing a catheter with excellent operability and a method for clamping the catheter.
[0012] To address the aforementioned issues, one aspect of the present invention is a catheter for the hepatic artery inserted into a patient's arm, characterized by having a tubular body extending from a base to a front end, the tubular body having an inner layer, an outer layer, and a reinforcing body embedded within the tubular body, the tubular body having a generally straight main body portion and a shape portion that is shaped by bending substantially in the same plane, the shape portion having: a first curved portion having a first angle defined on the front end side compared to the main body portion; a second curved portion having a second angle defined on the front end side compared to the first curved portion and bending toward the same side as the first curved portion; a third curved portion having a third angle defined on the front end side compared to the second curved portion and bending toward the opposite side to the second curved portion; and a foremost end portion disposed on the front end side compared to the third curved portion, having a point of change in physical properties between the end portion on the base side of the first curved portion and the end portion on the front end side of the second curved portion.
[0013] Invention Effects
[0014] As described above, the catheter's shape is stabilized by placing the point of change in physical properties between the base of the first bend and the tip of the second bend, ensuring contact between the strong first bend and the descending aorta. Furthermore, because at least a portion of the flexible second bend engages well with the celiac artery, and the flexible third bend, positioned at the tip compared to the point of change in physical properties, bends in the opposite direction to the second bend, the tip easily faces the common hepatic artery. Therefore, this catheter provides excellent support for other inserted medical devices. Additionally, because the shape with the point of change in physical properties easily and firmly maintains its shape relative to the base, the catheter easily enters the descending aorta. Thus, the catheter's operability is improved.
[0015] Alternatively, the aforementioned point of change in physical properties can be positioned at the first bend. This allows the high-strength first bend to stably position the catheter's tip towards the celiac artery, and enables the flexible second bend, positioned at the tip compared to the point of change in physical properties, to deform in accordance with the celiac artery for deep engagement. Therefore, this catheter can provide good support for other medical devices inserted within it. Furthermore, because the second bend is flexible, it reduces the burden on the contacted vessel wall.
[0016] Alternatively, the aforementioned point of change in physical properties may be located at the second bend. Consequently, due to the increased strength of the first and second bends, the range within which the shape of the portion can be firmly maintained increases, making it easier for the catheter to enter the descending aorta from the subclavian artery.
[0017] Alternatively, the aforementioned point of change in physical properties can be positioned between the first and second bends. This allows the high-strength first bend to stably position the catheter's tip towards the celiac artery, while the softer second bend, positioned at the tip compared to the point of change in physical properties, deforms to match the celiac artery and engages with its depth. Therefore, this catheter can provide good support for other inserted medical devices. Furthermore, because the second bend is soft, it reduces the burden on the contacted vessel wall. Moreover, the increased overall strength of the first bend allows for a wider range of shape retention, facilitating catheter entry from the subclavian artery into the descending aorta.
[0018] Alternatively, the aforementioned point of change in physical properties may be at the end of the reinforcing member. Since the reinforcing member hardens, the point of change in physical properties can be easily set without changing the resin of the inner or outer layer.
[0019] Alternatively, when the second curved portion is configured to contact the wall of the celiac artery, the foremost end faces the common hepatic artery, and the first curved portion contacts the wall of the descending aorta on the opposite side of the celiac artery. This allows the second curved portion to engage well with the celiac artery while maintaining stable contact between the strong first curved portion and the wall of the descending aorta on the opposite side of the celiac artery.
[0020] To address the aforementioned issues, another aspect of the present invention is a catheter clamping method, characterized by the following steps: inserting a catheter into an artery in a patient's arm, wherein the catheter has a tubular body extending from a base to a tip, the tubular body having an inner layer, an outer layer, and a reinforcing body embedded within the tubular body, the tubular body having a generally straight main body portion and a shape portion that is bent substantially in the same plane and thus shaped, the shape portion having: a first curved portion disposed on the tip side compared to the main body portion; a second curved portion disposed on the tip side compared to the first curved portion and bent toward the same side as the first curved portion; and a third curved portion disposed on the tip side compared to the second curved portion and bent toward the same side as the first curved portion. The second curved portion bends to the opposite side; and the foremost end portion, which is disposed at the front end side compared to the third curved portion, has a point of change in physical properties between the end portion at the base end side of the first curved portion and the end portion at the front end side of the second curved portion; the step of advancing the shaped portion of the catheter toward the aorta that can enter from the artery of the arm; the step of advancing the shaped portion toward the first blood vessel connected in a direction intersecting the long axis of the aorta; and the step of contacting the second curved portion with the wall of the first blood vessel, and abutting the first curved portion against the wall of the aorta on the opposite side of the first blood vessel, and advancing the foremost end portion toward the selected second blood vessel among the blood vessels that branch into at least two on the terminal side of the first blood vessel.
[0021] The catheter engagement method described above stabilizes the position of the catheter's shaped portion by bringing the strong first bend into contact with the descending aorta. Furthermore, at least a portion of the flexible second bend engages well with the first blood vessel, so that the tip faces the second blood vessel. Therefore, the surgeon can easily insert other medical instruments into the second blood vessel using the catheter as a guide. Attached Figure Description
[0022] Figure 1 It is a schematic diagram showing the arrangement of catheters inside blood vessels.
[0023] Figure 2 This is a plan view showing the front end of the conduit in the embodiment.
[0024] Figure 3 This is a plan view showing the front end of the conduit in the embodiment.
[0025] Figure 4 This is a cross-sectional view showing a portion of the conduit in an embodiment.
[0026] Figure 5 This is a plan view of a three-point bending tester.
[0027] Figure 6 This is a schematic diagram showing the state of the catheter being inserted into the descending aorta.
[0028] Figure 7 This is a schematic diagram showing the state of the catheter being inserted into the celiac artery.
[0029] Figure 8 These are plan views showing the position of the end of the reinforcing body as the point of change in physical properties. (A) is a variation of Example 1, and (B) is a variation of Example 2.
[0030] Figure 9 This is an overall view of the catheter with a portion of its length omitted from Example 1.
[0031] Figure 10 This is an overall view of the catheter with a portion of its length omitted in Example 2. Detailed Implementation
[0032] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, for ease of explanation, the dimensions in the drawings may sometimes be exaggerated and differ from the actual dimensions. Additionally, in this specification and the accompanying drawings, repetitive descriptions are omitted by using the same reference numerals to denote substantially identical functional components. In this specification, the side into which the tube is inserted is referred to as the "front end side," and the side where operation is performed is referred to as the "base end side."
[0033] like Figure 1 , 7 As shown, the catheter 1 in this embodiment is a catheter used to reach the common hepatic artery 105. The catheter 1 is inserted into a blood vessel from an artery 100 (e.g., the radial artery) in the patient's arm and proceeds to the vicinity of the hepatic artery. The catheter 1 can be a so-called guiding catheter, angiography catheter, guidewire support catheter, or microcatheter. Alternatively, the catheter 1 can also be a combination of a guiding catheter and a microcatheter that is longer than the guiding catheter and inserted into the inner tube of the guiding catheter.
[0034] like Figures 1-3 As shown, the catheter 1 has a tubular body 2, a hub 5 disposed on the base end side of the tubular body 2, and an anti-kink protector 4.
[0035] The tubular body 2 is long and flexible. A lumen 21 extending from the base to the front end is formed in the general center of the tubular body 2.
[0036] The seat 5 forms a passage communicating with the lumen 21. The seat 5 can be used, for example, to insert or remove a guidewire 6 or a therapeutic catheter 7. In addition, the seat 5 can be used to inject various liquids such as X-ray contrast agents, medications, and saline.
[0037] The anti-kink protector 4 is formed of an elastic material. The anti-kink protector 4 covers the portion where the tubular body 2 connects to the seat 5. Thus, the anti-kink protector 4 prevents the tubular body 2 from bending or kinking near this portion. Alternatively, a flexible anti-kink tube 8 with an outer diameter larger than the tubular body 2 can be provided between the anti-kink protector 4 and the tubular body 2 for insertion into the base end of the tubular body 2 and fixing it to the seat 5. Alternatively, the anti-kink protector 4 can be omitted, and only the anti-kink tube 8 can be provided.
[0038] The tubular body 2 is described in detail. For example... Figure 4 As shown, the tubular body 2 is composed of multiple layers, including an inner layer 31 forming the inner surface of the lumen 21, an outer layer 32 formed on the outer side of the inner layer 31, and a reinforcing body 33 embedded in the tubular body 2. Furthermore, the resins of the inner layer 31 and the outer layer 32 can be the same, or they can have different colors, hardness, contrast agents, etc.
[0039] The inner layer 31 has a cavity 21 formed inside. The material of the inner layer 31 can be thermoplastic resin or thermosetting resin, preferably fluoropolymers such as polytetrafluoroethylene (PTFE) and low-friction materials such as high-density polyethylene (HDPE), or various thermoplastic elastomers such as polyurethane, polyester, polyamide, polybutadiene, trans-polyisoprene, fluororubber, and chlorinated polyethylene.
[0040] The outer layer 32 is a tubular component that covers the outer periphery of the inner layer 31. The outer layer 32 forms the radially outer surface of the tubular body 2. The outer layer 32 can be made of materials such as styrene, polyolefins, polyurethanes, polyesters, polyamides, polybutadienes, trans-isoprene, fluororubbers, chlorinated polyethylenes, various thermoplastic elastomers, polyetherketones, polyimides, etc., and can use one or more of these materials in combination (polymer alloys, polymer blends, laminates, etc.). The outer layer 32 may also contain X-ray imaging materials.
[0041] The reinforcing body 33 is embedded in the tubular body 2. That is, the reinforcing body 33 is disposed between the inner surface and the outer surface of the tubular body 2. The reinforcing body 33 is formed by braiding multiple wires 34 into a tubular shape with gaps. The reinforcing body 33 can be wound with the wires 34 in a transverse winding in the same direction, or with right-hand / left-hand winding, etc., while changing the winding direction. In addition, the winding pitch, grid spacing, and tilt angle relative to the circumference can be changed according to the position, and its structure is not particularly limited.
[0042] The wire diameter of the reinforcing body 33 is not particularly limited, for example, it is 0.04 to 0.05 mm. The cross-sectional shape of the wire 34 is not particularly limited, for example, it is circular, elliptical, quadrilateral, etc.
[0043] The wire 34 used for the reinforcement 33 can be made of metal wires such as stainless steel, platinum (Pt) / tungsten (W), resin fiber, carbon fiber, glass fiber, etc., or multiple of these wires 34 can be used together.
[0044] like Figure 2 and 3As shown, the tubular body 2, comprising an inner layer 31, an outer layer 32, and a reinforcing body 33, has a generally straight main body portion 23 and a shaped portion 24. The shaped portion 24 is substantially curved within the same plane (the same plane). The shaped portion 24 may also include a straight portion. The shaped portion 24 has a first curved portion 25, a second curved portion 26, a third curved portion 27, and a foremost end portion 28. The first curved portion 25 extends from a first intermediate point P1 located at the front end of the main body portion 23 toward the front end, and simultaneously curves within the plane. The second curved portion 26 extends from a second intermediate point P2 located at the front end of the first curved portion 25 toward the front end, and simultaneously curves within the plane in the same direction as the first curved portion 25. The second intermediate point P2 is the portion with the largest radius of curvature between the first curved portion 25 and the second curved portion 26. When the portion with the largest radius of curvature between the first curved portion 25 and the second curved portion 26 has a defined range along the centerline of the tubular body 2, the second intermediate point P2 can, for example, be defined as the center of the centerline along that range. A straight section may also be provided within a predetermined range (length) between the first bend 25 and the second bend 26. The third bend 27 extends forward from the third intermediate point P3 located at the front end of the second bend 26, and simultaneously bends in the plane in the opposite direction to the second bend 26. The third intermediate point P3 is the point with the largest radius of curvature between the second bend 26 and the third bend 27. When the point with the largest radius of curvature between the second bend 26 and the third bend 27 has a predetermined range along the centerline of the tubular body 2, the third intermediate point P3 can, for example, be defined as the center of the centerline along that range. A straight section may also be provided within a predetermined range (length) between the second bend 26 and the third bend 27. The foremost end portion 28 extends straight forward from the fourth intermediate point P4 located at the front end of the third bend 27. The fourth intermediate point P4 is located at the base of the substantially straight foremost end portion 28. Furthermore, "in fact, bending in the same plane" means, in addition to bending in the same plane, that the front end of the conduit 1 protrudes slightly from the plane to the extent that it can achieve the same effect in practical use.
[0045] The axis passing through the center line of the main body 23 is designated as the first axis A. The tangent or straight line to the center line of the tubular body 2 at the second intermediate point P2 is designated as the second axis B. The tangent to the center line of the tubular body 2 at the third intermediate point P3 is designated as the third axis C. The axis passing through the center line of the foremost end 28 is designated as the fourth axis D.
[0046] The angle formed by the second axis B relative to the first axis A at the front end is defined as the first angle θ4. The first angle θ4 is the amount of change in the direction of the centerline of the tubular body 2 within the first curved section 25. That is, the first curved section 25 is defined by the first angle θ4. The radius of curvature of the first curved section 25 can be constant, but it can also vary. In the first curved section 25, the first minimum radius of curvature R1 at the location with the smallest radius of curvature (the most abruptly curved location) is preferably 10–80 mm, more preferably 15–60 mm, and even more preferably 20–55 mm. Figure 2 In the example, the first minimum radius of curvature R1 is 30 mm. Additionally, the radius of curvature at the second intermediate point P2 is 50 mm. The first angle θ4 is preferably 10–120°, more preferably 45–90°, and even more preferably 60–80°. Figure 2 In the example, the first angle θ4 is 70°.
[0047] The angle formed by the third axis C relative to the second axis B at the front end is defined as the second angle θ5. The second angle θ5 is the amount of change in the direction of the centerline of the tubular body 2 within the second bend 26. That is, the second bend 26 defines the second angle θ5. The radius of curvature of the second bend 26 can be constant, but it can also vary. In the second bend 26, the second minimum radius of curvature R2 at the location with the smallest radius of curvature (the most sharply bent location) is preferably 5–15 mm, more preferably 7–12 mm, and even more preferably 8–11 mm. Figure 2 In this example, the second minimum radius of curvature R2 is 9 mm. The second angle θ5 is preferably 10–170°, more preferably 55–100°, and even more preferably 70–90°. Figure 2 In the example, the second angle θ5 is 80°. The second minimum radius of curvature R2 is smaller than the first minimum radius of curvature R1.
[0048] The angle formed by the fourth axis D relative to the third axis C at the front end is defined as the third angle θ3. The third angle θ3 is the amount of change in the direction of the centerline of the tubular body 2 within the third bend 27. That is, the third angle θ3 is defined for the third bend 27. The radius of curvature of the third bend 27 can be constant, but it can also vary. In the third bend 27, the third minimum radius of curvature R3 at the location with the smallest radius of curvature (the most sharply bent location) is preferably 1–9 mm, more preferably 2–8 mm, and even more preferably 4–7 mm. Figure 2 In the example, the third minimum radius of curvature R3 is 5 mm. The third angle θ3 is preferably greater than 0° and less than 90°, more preferably 20–70°, and even more preferably 30–60°. Figure 2 In the example, the third angle θ3 is 45°.
[0049] The intersection of the first axis A and the second axis B is defined as the first intersection point E1, the intersection of the second axis B and the third axis C is defined as the second intersection point E2, and the intersection of the third axis C and the fourth axis D is defined as the third intersection point E3.
[0050] The distance L1 between the first intersection point E1 and the second intersection point E2 is preferably 5-100 mm, more preferably 20-60 mm, and even more preferably 30-50 mm. Figure 2 In the example, the distance L1 is 34mm.
[0051] The distance L2 between the second intersection point E2 and the third intersection point E3 is preferably 1–80 mm, more preferably 5–50 mm, and even more preferably 10–20 mm. Figure 2 In the example, the distance L2 is 12mm.
[0052] The distance L3 between the third intersection point E3 and the foremost point of the foremost end 28 is preferably 0.1–60 mm, more preferably 1–40 mm, and even more preferably 2–30 mm. Figure 2 In the example, the distance L3 is 3.5mm.
[0053] The length L4 along the center line of the foremost end portion 28 is preferably 0.1–50 mm, more preferably 0.5–30 mm, and even more preferably 1–20 mm. Figure 2 In the example, the length L4 is 1.4 mm.
[0054] In the second bend 26, the point with the smallest radius of curvature (the most abrupt bend) is defined as the second bend point P5. In the second bend 26, if the point with the smallest radius of curvature has a defined range along the centerline of the tubular body 2, the second bend point P5 can, for example, be defined as the center of the centerline along that range. The axis passing through the second bend point P5 and the first intermediate point P1 located at the front end of the main body 23 is defined as the fifth axis F. The angle formed by the fifth axis F relative to the first axis A at the front end is defined as the first tilt angle θ1. The first tilt angle is preferably 10–110°, more preferably 34–63°, and even more preferably 40–50°. Figure 2 In the example, the first tilt angle θ1 is 46°. The larger the first tilt angle θ1 is, the greater the bending of the tubular body 2.
[0055] The second tilt angle θ2 is the angle range within which the second curved portion 26 has a second minimum radius of curvature R2. That is, the second curved portion 26 has a second minimum radius of curvature R2 within the range of the second tilt angle θ2. The second tilt angle θ2 is preferably 5–120°, more preferably 10–90°, and even more preferably 38–80°. Figure 2 In the example, the second tilt angle θ2 is 73°.
[0056] The angle formed by the fourth axis D relative to the first axis A at the front end is defined as the third tilt angle θ6. The third tilt angle θ6 is the angle formed by the foremost end portion 28 relative to the main body portion 23. The third tilt angle θ6 is preferably 0 to 240° or less, more preferably 80 to 150°, and even more preferably 90 to 120°. Figure 2 In the example, the third tilt angle θ6 is 105°.
[0057] Alternatively, the radius of curvature of the second intermediate point P2 can be 40 mm or more, more preferably 50 mm or more, and even more preferably, the second intermediate point P2 is a roughly straight line. Furthermore, the straight line G connecting the second intermediate point P2 and the second bending point P5 runs from the second intermediate point P2 towards the second bending point P5 in a direction away from the main body 23, and is also away from the seat 5 in the extension direction of the main body 23. In other words, the angle θ7 formed by the intersection point E4 of the second intermediate point P2, 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 prevent accidental insertion into the left gastric artery 106 or the splenic artery 107. Figure 2 In the example, θ7 is 102°.
[0058] A reinforcing body 33 is embedded in the tubular body 2 within a predetermined range extending from the base end toward the front end. The front end 35 of the reinforcing body 33 is disposed between the base end 25A of the first bend 25 and the front end 26A of the second bend 26. In this embodiment, the front end 35 of the reinforcing body 33 is disposed between the first bend 25 and the second bend 26.
[0059] The catheter 1 can also be covered with a lubricating coating from the anterior opening 22 along the axis toward the base. The lubricating coating can cover the entire length, for example, covering the area from the anterior opening 22 along the axis toward the base to at least 400 mm, more preferably at least 200 mm. Therefore, the surgeon can also insert the catheter 1 to a depth of the common hepatic artery 105. Examples of materials that can be used to make lubricating coatings include: copolymers of epoxy-containing monomers such as glycidyl acrylate, glycidyl methacrylate, 3,4-epoxycyclohexyl methyl acrylate, 3,4-epoxycyclohexyl methyl methacrylate, β-methylglycidyl methacrylate, and allyl glycidyl ether with hydrophilic monomers such as N-methacrylamide, N,N-dimethylacrylamide, and acrylamide; (co)polymers composed of the above-mentioned hydrophilic monomers; cellulose-based polymers such as hydroxypropyl cellulose and hydroxymethyl cellulose; polysaccharides, polyvinyl alcohol, methyl vinyl ether-maleic anhydride copolymer, water-soluble polyamides, poly((meth)acrylate-2-hydroxyethyl ester), polyethylene glycol, polyacrylamide, and polyvinylpyrrolidone.
[0060] The outer diameter of the tubular body 2 is preferably 1 mm (3Fr) to 2.5 mm (6Fr), more preferably 1.3 mm (4Fr) to 1.8 mm (5Fr). The effective length of the tubular body 2 is preferably 800 to 1800 mm, more preferably 1000 to 1800 mm, further preferably 1000 to 1500 mm, and even more preferably selected from 1100 mm, 1200 mm, 1250 mm, or 1300 mm depending on the patient's physique or the reason for insertion into the distal radial artery or snuff bottle radial artery. The tubular body 2 is preferably selectable appropriately according to the patient or the blood vessel to be inserted. For example, when the catheter 1 is inserted into the brachial artery of a short woman, the effective length of the tubular body 2 is preferably shorter. When the catheter 1 is inserted into the distal radial artery of a tall man, the effective length of the tubular body 2 is preferably longer. The effective length is the length of the portion that can be inserted into a blood vessel or sheath. In this embodiment, the effective length is the length from the front end of the anti-kink protector 4 to the front end of the tubular body 2.
[0061] The length L5 along the central axis of the tubular body 2, from the end 25A on the base side of the first curved portion 25 of the tubular body 2 to the end 35 on the front 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 front side of the reinforcing member 33 of the tubular body 2 to the front end of the tubular body 2, is preferably 1 to 50 mm, more preferably 20 to 30 mm. Furthermore, the length along the central axis of the tubular body 2 is the same as the length when the tubular body 2 is deformed into a straight shape. The length L7 from the end 25A on the base side of the first curved portion 25 of the tubular body 2 to the front end of the tubular body 2 is the sum of the above lengths L5 and L6, preferably 40 to 75 mm, more preferably 50 to 75 mm.
[0062] The L6 / L7 ratio is preferably 1 to 100%, more preferably 10 to 60%, and even more preferably 10 to 40%. Alternatively, the L6 / L5 ratio is preferably 1 to 200%, 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%.
[0063] The tubular body 2 has a flexible portion 36 without the reinforcement 33 at its front end compared to the portion where the reinforcement 33 is embedded. Because the catheter 1 has the flexible portion 36, it can move within tortuous or branching blood vessels without damaging them. The length of the flexible portion 36 is the same as the aforementioned 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 a lower bending characteristic than the portion where the reinforcement 33 is provided. The bending characteristic can be the flexural modulus, a measured value of load or stress obtained based on a three-point bending test, etc. The flexural modulus of at least a portion of the tubular body 2 is preferably 2 to 25 MPa, more preferably 4 to 20 MPa, further preferably 7 to 13 MPa, and even more preferably 9 to 10 MPa. The load obtained from the three-point bending test at the portion of the tubular body 2 where the reinforcing member 33 is located is preferably 20 to 250 gf, more preferably 40 to 120 gf. When the outer diameter of the conduit 1 is 4 Fr, the bending characteristic (load) is preferably 40 gf or more. When the outer diameter of the conduit 1 is 5 Fr, the bending characteristic (load) is preferably 80 gf or more.
[0064] Figure 5 This example illustrates the measurement of bending characteristics using a three-point bending test. As for the measurement conditions, for example, the room temperature is 25°C, the distance S between the support points of the support platform 71 is 25.4 mm (1 inch), the test speed of the indenter 72 pressing against the center position between the support points from opposite sides is 5 mm / min, and the indentation depth T of the indenter 72 is 2 mm. The width W1 of the indenter is 1.0 mm, and the radius of curvature r1 of the indenter is 0.5 mm. The width W2 of each support point 73 of the support platform 71 is 4.0 mm, and the radius of curvature r2 of each support point 73 is 0.5 mm. The indentation load measured under these conditions can be used as a measure of the bending characteristics.
[0065] The tubular body 2 may also have a pointed tip at its anterior end that is more flexible than the base end. The pointed tip is made of a flexible material such as rubber.
[0066] The number of layers constituting the tubular body 2, the materials of each layer, and the presence or absence of reinforcing elements can also vary along the length of the tubular body 2.
[0067] Next, the method of using the catheter 1 in this embodiment will be described.
[0068] like Figure 1As shown, catheter 1 is inserted into a blood vessel through an artery 100 in the arm and engages with the celiac artery 104. The artery 100 in the arm through which catheter 1 is inserted can be, for example, the distal radial artery, conventional radial artery, ulnar artery, distal ulnar artery, brachial artery, or snuffbox-radial artery. Here, the case of inserting catheter 1 into an artery in the left arm is described as an example. However, catheter 1 can also be inserted into an artery in the right arm.
[0069] During the procedure, the surgeon inserts a guidewire 6 into the artery 100 of the arm. Next, the surgeon advances a catheter 1, containing the guidewire 6 within its lumen 21, along the guidewire 6. Typically, 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 nearly straight shape by passing through the guidewire 6 within the lumen 21.
[0070] like Figure 6 As shown, the guidewire 6 and catheter 1 pass through the subclavian artery 101 and proceed toward the aortic arch 102. At the junction of the subclavian artery 101 and the aortic arch 102, the catheter 1 needs to be significantly curved in order to approach the descending aorta 103. To address this, the surgeon can, for example, temporarily retract the guidewire 6 to accommodate it within the lumen 21 of the catheter 1. This restores the shape portion 24 of the catheter 1 to its original curved shape. The surgeon can then use the curvature of the shape portion 24 to advance the tip of the catheter 1 from the aortic arch 102 toward the descending aorta 103. Because the shape portion 24 is easily maintained due to the reinforcement 33, the catheter 1 can easily enter the descending aorta 103 from the subclavian artery 101. Afterward, the surgeon protrudes the guidewire 6 from the catheter 1. This allows the guidewire 6 to easily advance toward the descending aorta 103. The surgeon then advances the catheter 1 along the guidewire 6. Thus, catheter 1 can easily travel from the aortic arch 102 to the descending aorta 103. Catheter 1 moves downward X (towards the lower limb) in the descending aorta 103 and reaches the vicinity of the celiac artery 104.
[0071] After the guidewire 6 and catheter 1 reach the vicinity of the entrance to the celiac artery 104, the surgeon retracts the guidewire 6 to accommodate it within the lumen 21 of the catheter 1. Thus, as... Figure 7As shown, the shape portion 24 of catheter 1 returns to its original curved shape. The surgeon can use the curvature of the shape portion 24 to insert the tip of catheter 1 into the celiac artery 104. The celiac artery 104 extends generally anteriorly (ventrally) from the descending aorta 103. Branches from the celiac artery 104 are the common hepatic artery 105, the left gastric artery 106, and the splenic artery 107. The common hepatic artery 105 extends generally downward (X-shaped, closer to the lower limb) from the celiac artery 104. The left gastric artery 106 and the splenic artery 107 extend generally upward (Y-shaped, closer to the head) from the celiac artery 104. The second curved portion 26 of catheter 1 contacts the vessel wall of the celiac artery 104, and the first curved portion 25 contacts the vessel wall of the descending aorta 103 on the opposite side from the entrance of the celiac artery 104. The second curved portion 26 contacts the vessel wall of the celiac artery 104 on the inferior (X-shaped) side. Thus, the second bend 26 of catheter 1 can engage with the celiac artery 104. In this state, the third bend 27 bends to the opposite side of the first bend 25 and the second bend 26. Therefore, the tip of catheter 1 is easily oriented toward the common hepatic artery 105 extending downward X from the celiac artery 104. The third bend 27 and / or the tip 28 may or may not contact the vessel wall of the common hepatic artery 105.
[0072] The catheter 1 has an end portion 35 on the front end side of the reinforcing body 33, which serves as a point of change in physical properties, positioned at a predetermined distance (e.g., 20-30 mm) from the tip. Therefore, by ensuring that the soft portion 36 on the front end side, compared to the reinforcing body 33, contacts the wall of the celiac artery 104, its position is stabilized. Furthermore, since the reinforcing body 33 is not provided in the soft portion 36, the freedom of vessel selection in the celiac artery 104, which has many branches and bends, is increased, or vessel selection based on the guidewire 6 becomes easier. In addition, the coronary artery guiding catheter has its front-end bend portion for hooking onto the coronary artery ostium positioned on the aortic side; therefore, the reinforcing body is typically positioned up to the soft tip, about 2-3 mm from the tip, i.e., up to the front-end bend portion. In contrast, the catheter 1 of this embodiment is a hepatic artery catheter, into which at least the second bend portion 26 is inserted into the celiac artery 104; therefore, its construction and engagement method differ from those of the coronary artery guiding catheter. In addition, unlike Jacky-type or Sarah-type catheters which protrude due to sharp bending, the first bend 25 is smoothly curved, thus enabling smooth contact with the blood vessel wall and reducing the burden on the blood vessel.
[0073] Furthermore, conventional catheters inserted into the femoral artery and engaged with the celiac artery 104 are generally arranged in a straight line from the femoral artery to the celiac artery 104, thus providing support even without the reinforcing body 33 in the shape portion. However, when this conventional catheter is introduced from an artery in the arm, there is a risk of "prolapse" due to the injection of contrast agent or the operation of the microcatheter, where part of the catheter bends toward the ascending aorta opposite to the descending aorta 103.
[0074] Even to prevent dislodgement, the end 35 (the point of change in physical properties) of the reinforcing member 33 of the conduit 1 is preferably located between the end 25A on the base side of the first bend 25 and the end 26A on the front end side of the second bend 26. The bending stiffness of the conduit 1 changes significantly at the point of change in physical properties and decreases towards the front end. In addition to the end 35 of the reinforcing member 33, the hardness of the resin of the outer layer 32 and / or the inner layer 31 can be changed at the point of change in physical properties to make it softer towards the front end, or the conduit 1 can be made to taper towards the front end.
[0075] In addition, in order to make the resilient force of the conduit 1 greater, the end 35 of the reinforcing body 33 can be located near the second intermediate point P2 with the largest radius of curvature, or it can be aligned with the second intermediate point P2.
[0076] Next, a treatment catheter 7, longer than catheter 1, is inserted into the lumen 21 of catheter 1 from the seat 5. The surgeon can make the treatment catheter 7 protrude from the tip of catheter 1 and easily insert it into the common hepatic artery 105. At this time, since the tip of catheter 1 faces downward X from celiac artery 104, it is possible to prevent the treatment catheter 7 from being mistakenly inserted into left gastric artery 106 or splenic artery 107 facing upward Y. The surgeon can then insert the treatment catheter 7 into common hepatic artery 105 and release embolic agents or medications through the treatment catheter 7. Catheter 1 mitigates the reaction caused by the insertion of treatment catheter 7 or guidewire 6. Moreover, catheter 1 can apply support to treatment catheter 7 to hold it in the desired position. Furthermore, the medical device inserted into catheter 1 may not be treatment catheter 7.
[0077] As described above, the catheter 1 of this embodiment is a hepatic artery catheter inserted into the patient's arm. It has a tubular body 2 extending from the base to the tip. 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 generally straight main body portion 23 and a shape portion 24 that is shaped by bending in the same plane. The shape portion 24 has: a first curved portion 25, which defines a first angle θ4 on the tip side compared to the main body portion 23; a second curved portion 26, which defines a second angle θ5 on the tip side compared to the first curved portion 25 and bends toward the same side as the first curved portion 25; a third curved portion 27, which defines a third angle θ3 on the tip side compared to the second curved portion 26 and bends toward the opposite side of the second curved portion 26; and a foremost end portion 28, which is disposed on the tip side compared to the third curved portion 27. There is a point of change in physical properties between the end portion 25A on the base side of the first curved portion 25 and the end portion 26A on the tip side of the second curved portion 26.
[0078] As described above, the catheter 1 has a property change point located between the base end 25A of the first bend 25 and the front end 26A of the second bend 26. Therefore, by bringing the strong first bend 25 into contact with the descending aorta 103, the position of the shape portion 24 of the catheter 1 is stabilized. Furthermore, since at least a portion of the flexible second bend 26 engages well with the celiac artery 104, and the flexible third bend 27, located on the front end compared to the property change point, bends to the opposite side of the second bend 26, the foremost end 28 easily faces the common hepatic artery 105. Therefore, this catheter 1 can provide good support for other medical devices such as the therapeutic catheter 7 or guidewire 6 inserted inside. In addition, since the shape portion 24 with the property change point easily and firmly maintains the shape of the portion closer to the base compared to the property change point, the catheter 1 can easily enter the descending aorta 103 from the subclavian artery 101 (left or right subclavian artery). Therefore, the operability of the catheter 1 is improved.
[0079] Furthermore, the point of change in physical properties is positioned between the first bend 25 and the second bend 26. This allows the high-strength first bend 25 to stably position the distal end of the catheter 1 towards the celiac artery 104, and enables the flexible second bend 26, positioned at the distal end compared to the point of change in physical properties, to deform in accordance with the celiac artery 104 for deep engagement. Therefore, this catheter 1 can provide good support for other medical devices such as the therapeutic catheter 7 or guidewire 6 inserted inside. Additionally, the flexibility of the second bend 26 reduces the burden on the contacted vessel wall. Moreover, the increased overall strength of the first bend 25 allows for a larger range of secure maintenance of the shape of the shape portion 24, facilitating the catheter 1's entry from the subclavian artery 101 into the descending aorta 103.
[0080] Furthermore, the point of change in physical properties is the end 35 of the reinforcing member 33. Since the reinforcing member 33 hardens, the point of change in physical properties can be easily set without changing the resin of the inner layer 31 or the outer layer 32.
[0081] Furthermore, when the second bend 26 is configured to contact the wall of the celiac artery 104, the foremost end 28 faces the common hepatic artery 105, and the first bend 25 contacts the wall of the descending aorta 103 on the opposite side of the celiac artery 104. Thus, the second bend 26 can be well engaged with the celiac artery 104 while maintaining stable contact between the strong first bend 25 and the wall of the descending aorta 103 on the opposite side of the celiac artery 104.
[0082] In addition, the present invention also includes a method for engaging the catheter 1. The method for engaging the catheter 1 includes the following steps: inserting the catheter 1, which has a point of change in physical properties between the base end 25A of the first bend 25 and the front end 26A of the second bend 26, into an artery (e.g., the radial artery 100) of the arm; advancing the shaped portion 24 of the catheter 1 toward an aorta (e.g., the descending aorta 103) that can be accessed from the artery of the arm; advancing the shaped portion 24 toward a first blood vessel (e.g., the celiac artery 104) that is connected in a direction intersecting the long axis of the aorta; and bringing the second bend 26 into contact with the wall of the first blood vessel, and bringing the first bend 25 into contact with the wall of the aorta on the opposite side of the first blood vessel, so that the foremost end 28 is directed toward a selected second blood vessel among at least two branches on the terminal side of the first blood vessel.
[0083] The method of engaging the catheter 1 as described above allows for the stabilization of the shape portion 24 of the catheter 1 by bringing the first curved portion 25, which is strengthened by the reinforcing body 33, into contact with the aorta. Furthermore, at least a portion of the flexible second curved portion 26 can be well engaged with the first blood vessel, with the tip 28 facing the second blood vessel. Therefore, the surgeon can easily insert other medical instruments into the second blood vessel using the catheter 1 as a guide.
[0084] Furthermore, the present invention is not limited to the embodiments described above, and various modifications can be made by those skilled in the art within the scope of the technical concept of the present invention. For example, the catheter 1 can be appropriately designed within the range of various angles, dimensions, etc., described above. For example, as Figure 8As shown in the first modified example (A), the end 35 of the reinforcing body 33, which is a point of change in physical properties, can also be disposed in the first curved portion 25. Thus, the tip of the catheter 1 can be stably positioned towards the celiac artery 104 by bending the first curved portion 25, which has high strength due to the reinforcing body 33, and the softer second curved portion 26 disposed on the tip side compared to the reinforcing body 33 can be deformed to match the celiac artery 104 and engage with its depth. Therefore, this catheter 1 can provide good support for other medical devices inserted inside. Furthermore, since the second curved portion 26 is soft, the burden on the contacted blood vessel wall can be reduced.
[0085] In addition, such as Figure 8 As shown in the second modified example (B), the end 35 of the reinforcing body 33, which is the point of change in physical properties, can also be disposed in the second bend 26. As a result, since the strength of the first bend 25 and the second bend 26 is increased, the range in which the shape of the shape portion 24 can be firmly maintained is increased, and the catheter 1 can easily enter the descending aorta 103 from the subclavian artery 101.
[0086] The specific embodiments of the present invention will be described in detail below.
[0087] Example 1
[0088] Made Figure 9 The catheter 1 shown is equipped with an anti-torsion tube 8. The parameters of the catheter 1 are shown below.
[0089] Effective length: 1250mm
[0090] Outer diameter: 1.4mm (4Fr)
[0091] Inner diameter (lumen diameter): 1.1mm
[0092] Cross-sectional structure: a laminate of inner layer, reinforcing body, and outer layer.
[0093] Reinforcing wire diameter and construction: 0.04mm, double-layer mesh wire
[0094] Front-end lubricating coating length: 150mm
[0095] θ1: 47°
[0096] θ2: 77°
[0097] θ3: 45°
[0098] θ4: 70°
[0099] θ5: 85°
[0100] θ6: 102°
[0101] θ7: 97°
[0102] L1: 34mm
[0103] L2: 12mm
[0104] L3: 3.5mm
[0105] L4: 1.4mm
[0106] L5: 37mm
[0107] L6: 23mm
[0108] L7: 60mm
[0109] R1: 30mm
[0110] R1: 30mm
[0111] R2: 9mm
[0112] R3: 5mm
[0113] Radius of curvature at P2: 50mm
[0114] Example 2
[0115] Made Figure 10 The catheter 1 is shown. The parameters of catheter 1 are as follows.
[0116] Effective length: 1250mm
[0117] Outer diameter: 1.7mm (5Fr)
[0118] Inner diameter (lumen diameter): 1.2mm
[0119] Cross-sectional structure: The inner layer, the reinforcing body, and the outer layer are laminated. The diameter and structure of the reinforcing wires are 0.05mm, with double-layer mesh lines.
[0120] Front-end lubricating coating length: 150mm
[0121] θ1: 44°
[0122] θ2: 76°
[0123] θ3: 20°
[0124] θ4: 70°
[0125] θ5: 81°
[0126] θ6: 129°
[0127] θ7: 99°
[0128] L1: 34mm
[0129] L2: 12mm
[0130] L3: 3.5mm
[0131] L4: 1.4mm
[0132] L5: 37mm
[0133] L6: 23mm
[0134] L7: 60mm
[0135] R1: 30mm
[0136] R1: 30mm
[0137] R2: 9mm
[0138] R3: 5mm
[0139] Radius of curvature at P2: 50mm
[0140] Furthermore, the vessel clamped by catheter 1 is not limited to the celiac artery 104. For example, the vessel clamped by catheter 1 can also be the superior mesenteric artery, inferior mesenteric artery, renal artery, lumbar artery, splenic artery, left gastric artery, testicular artery, common iliac artery, internal iliac artery, prostatic artery, uterine artery, external iliac artery, coronary artery, etc.
[0141] Furthermore, 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, and their disclosures are incorporated herein by reference in their entirety.
[0142] Explanation of reference numerals in the attached figures
[0143] 1. Catheter
[0144] 2 tubular body
[0145] 6. Guide wire
[0146] 7. Therapeutic catheters
[0147] 8 Anti-torsion pipe
[0148] 21. Lumen
[0149] 23 Main body
[0150] 24 Shape section
[0151] 25 First bend
[0152] 26 Second bend
[0153] 27 Third bend
[0154] 28. The very front end
[0155] 31 Inner layer
[0156] 32 Outer layer
[0157] 33. Strengthening body
[0158] 34 wire
[0159] 35 Reinforced Body
[0160] 36. Soft part
[0161] 100 radial artery
[0162] 101 Subclavian artery
[0163] 102 Aortic arch
[0164] 103 Descending Aorta
[0165] 104 celiac arteries
[0166] 105 Common Hepatic Artery
[0167] 106 Left gastric artery
[0168] 107 Splenic artery.
Claims
1. A catheter inserted through a patient's arm and used for the hepatic artery, The catheter is characterized in that, It has a tubular structure that lies substantially in the same plane and is connected from the base to the front end. The tubular body has an inner layer, an outer layer, and a reinforcing body embedded in the tubular body. The tubular body has a straight main body and a shape portion that is curved in substantially the same plane to give it its shape. The shaped portion has: The first curved portion has a first angle defined on its front end side compared to the main body portion; The second bend has a second angle defined at its front end side compared to the first bend, and bends toward the same side as the first bend; The third bend has a third angle defined on its front end side compared to the second bend, and bends toward the side opposite to the second bend. and The foremost end portion, compared to the third curved portion, is located on the front end side. The first curved portion and the second curved portion are sandwiched by a portion that bends in the same direction as the first curved portion and the second curved portion with a radius of curvature larger than that of the first curved portion and the second curved portion, and are connected without sandwiching a straight portion. There is a property change point between the end of the first bend on the base side and the end of the second bend on the front end side. The bending stiffness of the conduit changes at the property change point and decreases towards the front end side.
2. The catheter according to claim 1, characterized in that, The point of change in physical properties is located at the first curved section.
3. The catheter according to claim 1, characterized in that, The point of change in physical properties is located at the second bending section.
4. The catheter according to claim 1, characterized in that, The point of change in physical properties is located between the first curved portion and the second curved portion.
5. The catheter according to any one of claims 1 to 4, characterized in that, The point of change in physical properties is at the end of the reinforcing body.
6. The catheter according to any one of claims 1 to 4, characterized in that, When the second bend is configured to contact the wall of the celiac artery, the foremost portion faces the common hepatic artery, and the first bend contacts the wall of the descending aorta on the opposite side of the celiac artery.
7. The catheter according to claim 5, characterized in that, When the second bend is configured to contact the wall of the celiac artery, the foremost portion faces the common hepatic artery, and the first bend contacts the wall of the descending aorta on the opposite side of the celiac artery.