Balloon catheter and method for manufacturing a balloon catheter

Abstract

This balloon catheter includes an inner layer tube, an outer layer, a balloon, and an adhesive layer. The outer layer is a member covering an outer circumferential surface of the inner layer tube. The balloon is a member covering an outer circumferential surface of the outer layer. An internal space of the balloon is in communication with a cavity of the inner layer tube. The adhesive layer is positioned between the inner layer tube and the outer layer.

Description

Technical Field

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[0001] The technology disclosed in this specification relates to a balloon catheter and a method for manufacturing the balloon catheter.

Background Art

[0002] A balloon catheter is a long medical device that is inserted into a body lumen such as a blood vessel to expand a stenosis in the body lumen or to occlude the body lumen to regulate the flow of fluid (e.g., blood flow).

[0003] A balloon catheter includes an inner layer tube, an outer layer covering the outer peripheral surface of the inner layer tube, and a balloon covering the outer peripheral surface of the outer layer (see, for example, Patent Document 1). The lumen of the inner layer tube communicates with the internal space of the balloon and functions as an expansion medium lumen. When expanding the balloon, an expansion medium (such as a contrast agent or physiological saline) is supplied toward the internal space of the balloon through the lumen of the inner layer tube serving as the expansion medium lumen. When shrinking the balloon, the expansion medium is discharged from the internal space of the balloon through the lumen of the inner layer tube serving as the expansion medium lumen.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a balloon catheter, when discharging the expansion medium through the expansion medium lumen to shrink the balloon, a negative pressure is generated in the expansion medium lumen. In the configuration of a conventional balloon catheter, there is a risk that the inner layer tube may peel off from the outer layer and collapse due to the negative pressure generated in the expansion medium lumen, and there is room for improvement in terms of smooth discharge of the expansion medium through the expansion medium lumen.

[0006] This specification discloses a technology capable of solving the above-mentioned problems. [Means for solving the problem]

[0007] The technologies disclosed herein can be implemented, for example, in the following forms:

[0008] (1) The balloon catheter disclosed herein comprises an inner tube, an outer layer, a balloon, and an adhesive layer. The outer layer is a member that covers the outer surface of the inner tube. The balloon is a member that covers the outer surface of the outer layer. The internal space of the balloon is in communication with the lumen of the inner tube. The adhesive layer is positioned between the inner tube and the outer layer.

[0009] In this balloon catheter, the lumen of the inner tube communicates with the internal space of the balloon and functions as an expansion medium lumen. Furthermore, the inner tube is bonded to the outer layer by an adhesive layer. Therefore, when negative pressure is generated in the expansion medium lumen due to the discharge of the expansion medium through the expansion medium lumen, it is possible to suppress the inner tube from separating from the outer layer and collapsing. Consequently, with this balloon catheter, it is possible to suppress the reduction in the cross-sectional area of ​​the expansion medium lumen due to the separation and collapse of the inner tube, and to achieve smooth discharge of the expansion medium through the expansion medium lumen.

[0010] (2) In the balloon catheter described above, the hardness of the adhesive layer may be lower than that of at least a portion of the outer layer and at least a portion of the inner tube. With this configuration, the inner tube can be well adhered to the outer layer by the adhesive layer. Therefore, with this configuration, the peeling of the inner tube from the outer layer can be effectively suppressed, and smoother discharge of the expansion medium through the expansion medium lumen can be achieved.

[0011] (3) In the balloon catheter described above, the hardness of the inner tube may be set to be higher than that of the outer layer. With this configuration, when negative pressure is generated in the expansion medium lumen, the collapse of the inner tube can be effectively suppressed. Therefore, with this configuration, the collapse of the inner tube can be effectively suppressed, and smoother discharge of the expansion medium through the expansion medium lumen can be achieved.

[0012] (4) In the balloon catheter described above, the outer layer includes a first outer layer and a second outer layer positioned proximal to the first outer layer, and the hardness of the first outer layer may be lower than that of the second outer layer. With this configuration, the tip portion of the balloon catheter can be made relatively soft to improve its conformability to the lumen of the body, while the proximal portion of the balloon catheter can be made relatively hard to improve its ability to be pushed in.

[0013] (5) In the balloon catheter described above, the hardness of the adhesive layer may be lower than the hardness of the first outer layer, the hardness of the second outer layer, and the hardness of the inner tube. With this configuration, the inner tube can be well adhered to either the first outer layer or the second outer layer by the adhesive layer. Therefore, with this configuration, the peeling of the inner tube from the outer layers, including the first and second outer layers, can be effectively suppressed, and smoother discharge of the expansion medium through the expansion medium lumen can be achieved.

[0014] (6) In the balloon catheter described above, the hardness of the inner tube may be set to be higher than the hardness of the first outer layer and the hardness of the second outer layer. With this configuration, the collapse of the inner tube when negative pressure is generated in the expansion medium lumen can be suppressed more effectively. Therefore, with this configuration, the collapse of the inner tube can be suppressed more effectively, and the discharge of the expansion medium through the expansion medium lumen can be made smoother.

[0015] (7) A method for manufacturing a balloon catheter disclosed herein comprises: an inner tube; an outer layer covering the outer surface of the inner tube; and a balloon covering the outer surface of the outer layer, wherein the inside of the balloon is in communication with the lumen of the inner tube, and the method for manufacturing a balloon catheter comprises: preparing the inner tube on which an adhesive layer forming material is arranged on the outer surface; producing a precursor by covering the inner tube with the outer layer forming material; forming the outer layer by heating the precursor to melt the outer layer forming material and forming the adhesive layer between the inner tube and the outer layer. According to this method for manufacturing a balloon catheter, a balloon catheter in which the inner tube is bonded to the outer layer by the adhesive layer can be easily manufactured.

[0016] Furthermore, the technologies disclosed herein can be implemented in various forms, for example, in the form of a balloon catheter and a method for manufacturing the same. [Brief explanation of the drawing]

[0017] [Figure 1] An explanatory diagram showing the side view of the balloon catheter 100 in the first embodiment. [Figure 2] An explanatory diagram showing the cross-sectional configuration of the balloon catheter 100 in the first embodiment. [Figure 3] An explanatory diagram showing the longitudinal cross-sectional configuration of the balloon catheter 100 in the first embodiment. [Figure 4] An explanatory diagram showing the hardness of each component constituting the balloon catheter 100 in the first embodiment. [Figure 5] An explanatory diagram showing an example of a manufacturing method for the balloon catheter 100 in this embodiment. [Figure 6] An explanatory diagram showing an example of a manufacturing method for the balloon catheter 100 in this embodiment. [Figure 7] An explanatory diagram showing an example of a manufacturing method for the balloon catheter 100 in this embodiment. [Figure 8]Explanatory drawing showing the side configuration of the balloon catheter 100a in the second embodiment [Figure 9] Explanatory drawing showing the hardness of each member constituting the balloon catheter 100a in the second embodiment [Figure 10] Explanatory drawing showing the longitudinal cross-sectional configuration of the balloon catheter 100 in the modified example

Mode for Carrying Out the Invention

[0018] A. First Embodiment: A-1. Configuration of the balloon catheter 100: Figures 1 to 3 are explanatory drawings showing the configuration of the balloon catheter 100 in the first embodiment. In Figure 1, the side configuration of the balloon catheter 100 is shown. In Figure 2, the cross-sectional configuration of the balloon catheter 100 at the position II-II in Figure ① is shown. In Figure 3, the longitudinal cross-sectional configuration of the distal end portion (portion X1 in Figure 1) of the balloon catheter 100 is shown. In each figure, some illustrations of the balloon catheter 100 may be omitted. Also, in each figure, the positive Z-axis direction side is the distal end side (distal side) inserted into the body, and the negative Z-axis direction side is the proximal end side (proximal side) operated by a technician such as a doctor. Hereinafter, for the balloon catheter and its constituent members, the end on the distal end side is referred to as the "distal end", the distal end and its vicinity are referred to as the "distal end portion", the end on the proximal end side is referred to as the "proximal end", and the proximal end and its vicinity are referred to as the "proximal end portion". In Figure 1, the balloon catheter 100 is shown in a straight line state parallel to the Z-axis direction as a whole, but the balloon catheter 100 has flexibility enough to be curved.

[0019] The balloon catheter 100 is a long medical device for being inserted into a body lumen such as a blood vessel, expanding a stenosis in the body lumen by pushing it open, or occluding the body lumen to regulate the flow of fluid (for example, blood flow). The total length of the balloon catheter 100 is, for example, about 1500 mm to 2000 mm.

[0020] Note: There seems to be a mistake in the original text where "Figure ①" is mentioned in ID=18. It should probably be "Figure 1". This translation has been made with the best understanding of the context.The balloon catheter 100 of this embodiment is a balloon-equipped guiding catheter having a device lumen L2, which will be described later, for guiding the device. The balloon catheter 100 is used, for example, to stop blood flow during a procedure to retrieve a thrombus from a blood vessel in the brain using a thrombus retrieval catheter delivered via the device lumen L2, so that fragments of the detached thrombus do not flow through the blood vessel.

[0021] The balloon catheter 100 comprises an outer layer 10, a first inner tube 20, an adhesive layer 30, a second inner tube 40, a tip 50, a balloon 60, and a Y-connector 80.

[0022] The first inner tube 20 is a cylindrical (for example, cylindrical) member. The outer diameter of the first inner tube 20 is, for example, about 0.08 mm to 0.8 mm, and the wall thickness of the first inner tube 20 is, for example, about 10 μm to 80 μm. The lumen 21 of the first inner tube 20 functions as an expansion medium lumen L1 through which an expansion medium (contrast agent or physiological saline) for expanding the balloon 60 flows. The first inner tube 20 is an example of an inner tube in the claims.

[0023] The first inner layer tube 20 is formed from a flexible material. As the material for forming the first inner layer tube 20, for example, resin can be used, and more specifically, polyamide, polyamide elastomer, polyester, polyurethane, polyurethane elastomer, PEEK, etc. can be used.

[0024] The shape of the cross-section of the first inner tube 20 (an example of an inner tube in the claims) can be set as appropriate. Examples of the shape of the cross-section of the first inner tube 20 include a circular, elliptical, and polygonal shape. Examples of polygons include a square and a rectangle. If the shape of the cross-section of the first inner tube 20 is, for example, elliptical or rectangular, the size of the elliptical or rectangular first inner tube 20 along the radial direction can be made smaller than the size along the direction perpendicular to the radial direction. By setting the size in this way, the size of the first inner tube 20 along the radial direction can be reduced while keeping the area of ​​the expansion medium lumen L1 in the cross-section of the first inner tube 20 the same (without reducing the flow rate of the expansion medium), thereby making the balloon catheter 100 thinner.

[0025] The second inner tube 40 is a cylindrical (for example, cylindrical) member. The inner diameter of the second inner tube 40 is, for example, about 1.5 mm to 3.0 mm, and the wall thickness of the second inner tube 40 is, for example, about 5 μm to 30 μm. The lumen 41 of the second inner tube 40 functions as a device lumen L2 for inserting guide wires and various devices (for example, suction catheters and thrombectomy catheters).

[0026] The second inner layer tube 40 is formed from a flexible material. The material used to form the second inner layer tube 40 can be, for example, resin. More specifically, PTFE (polytetrafluoroethylene), PVDF (polyvinylidene fluoride), PFA (perfluoroalkoxyalkane), FEP (perfluoroethylenepropene), ETFE (ethylenetetrafluoroethylene), polyethylene, polypropylene, etc., can be used. Furthermore, a reinforcing body, for example, in which metal wires are woven in a mesh-like structure, may be arranged to cover the outer surface of the second inner layer tube 40.

[0027] The outer layer 10 is a cylindrical member that covers the outer circumferential surfaces of the first inner layer pipe 20 and the second inner layer pipe 40. In this specification, when member A covers the outer circumferential surface of member B, it means that member A is positioned outside at least a portion of the outer circumferential surface of member B, and does not exclude the possibility of other members being interposed between member A and the outer circumferential surfaces of member B. In this embodiment, the outer layer 10 covers substantially the entire outer circumferential surface of the first inner layer pipe 20 over substantially its entire length, and also covers substantially the entire outer circumferential surface of the second inner layer pipe 40 over substantially its entire length. The outer diameter of the outer layer 10 is, for example, about 2.0 mm to 3.5 mm.

[0028] The outer layer 10 is formed from a flexible material. For example, resin can be used as the material for forming the outer layer 10; more specifically, polyamide, polyamide elastomer, polyester, polyurethane, polyurethane elastomer, etc., can be used.

[0029] In this embodiment, the outer layer 10 is composed of a first outer layer 11 and a second outer layer 12 positioned closer to the base end than the first outer layer 11. The second outer layer 12 is connected to the base end of the first outer layer 11 so as to be substantially coaxial with the first outer layer 11. The hardness of the first outer layer 11 is lower than that of the second outer layer 12.

[0030] The adhesive layer 30 is positioned between the first inner layer pipe 20 and the outer layer 10, and is a layer that adheres the two together. That is, the first inner layer pipe 20 is adhered to the outer layer 10 by the adhesive layer 30. As the material for forming the adhesive layer 30, for example, a resin can be used, and more specifically, a urethane resin can be used. The second inner layer pipe 40 is directly joined to the outer layer 10, for example, by welding.

[0031] The tip 50 is a cylindrical (for example, cylindrical) member. The tip 50 is positioned at the tip end of the outer layer 10 and is joined to the tip of the outer layer 10, for example, by welding. The outer diameter of the tip 50 is approximately the same as the outer diameter of the outer layer 10. The lumen 51 of the tip 50 communicates with the lumen 41 of the second inner layer tube 40 and functions together with the lumen 41 of the second inner layer tube 40 as the device lumen L2. As the material for forming the tip 50, for example, resin can be used, and more specifically, for example, urethane resin can be used.

[0032] The balloon 60 is a hollow member with an internal space 61 formed within it, and can expand and contract in conjunction with the supply and discharge of the expansion medium. The balloon 60 covers the outer circumferential surface of the tip of the outer layer 10 and the outer circumferential surface of the tip 50. The tip of the balloon 60 is joined to the outer circumferential surface of the tip 50, for example by welding, and the base of the balloon 60 is joined to the outer circumferential surface of the tip of the outer layer 10, for example by welding.

[0033] As the material for forming the balloon 60, for example, resins and rubbers can be used. More specifically, polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or mixtures of two or more of these, thermoplastic resins such as flexible polyvinyl chloride resin, polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane, fluororesin, silicone rubber, latex rubber, etc. can be used.

[0034] As shown in Figure 3, the internal space 61 of the balloon 60 and the lumen 21 (expansion medium lumen L1) of the first inner tube 20 are in communication with each other. That is, the balloon catheter 100 has a communication channel (communication hole) C1 that extends radially from the inner circumferential surface at the tip of the first inner tube 20 to the outer circumferential surface of the outer layer 10, and the internal space 61 of the balloon 60 and the lumen 21 of the first inner tube 20 are in communication with each other through this communication channel C1.

[0035] The Y-connector 80 constitutes the proximal end of the balloon catheter 100. The Y-connector 80 has an expansion medium port 81 that communicates with the expansion medium lumen L1 and a device port 82 that communicates with the device lumen L2. When the balloon 60 is expanded, expansion medium is supplied from the expansion medium port 81 to the internal space 61 of the balloon 60 via the expansion medium lumen L1 and the communication channel C1. When the balloon 60 is deflated, the expansion medium present in the internal space 61 of the balloon 60 is discharged from the expansion medium port 81 via the communication channel C1 and the expansion medium lumen L1. Insertion of the device into the device lumen L2 and removal of the device from the device lumen L2 are performed via the device port 82. The balloon catheter 100 in this embodiment is a so-called over-the-wire (OTW) type balloon catheter.

[0036] A-2. Relationship between the hardness of each component: Figure 4 is an explanatory diagram showing the hardness of each component constituting the balloon catheter 100 in the first embodiment. As shown in Figure 4, in the balloon catheter 100 of this embodiment, the Shore hardness (A) of the adhesive layer 30 is 80, the Shore hardness (D) of the first outer layer 11 is 30, the Shore hardness (D) of the second outer layer 12 is 80, and the Shore hardness (D) of the first inner tube 20 is 2000. In other words, in the balloon catheter 100 of this embodiment, the hardness of the four components increases in the order of adhesive layer 30, first outer layer 11, second outer layer 12, and first inner tube 20. This relationship of hardness can be achieved, for example, by forming the adhesive layer 30 from urethane resin, the first outer layer 11 from a mixed material of urethane resin and nylon resin, the second outer layer 12 from nylon resin, and the first inner tube 20 from PEEK.

[0037] In the balloon catheter 100 of this embodiment, the relationship of the hardness of each component is as described above, and therefore the following relationships (1) to (5) hold true. (1) The hardness of the adhesive layer 30 is lower than the hardness of at least a portion of the outer layer 10 and the hardness of at least a portion of the first inner layer tube 20. (2) The hardness of the first inner layer tube 20 is higher than the hardness of the outer layer 10. (3) The hardness of the first outer layer 11 is lower than the hardness of the second outer layer 12. (4) The hardness of the adhesive layer 30 is lower than the hardness of the first outer layer 11, the hardness of the second outer layer 12, and the hardness of the first inner layer tube 20. (5) The hardness of the first inner layer tube 20 is higher than the hardness of the first outer layer 11 and the hardness of the second outer layer 12.

[0038] Furthermore, the relationship between the hardness of each of the above-mentioned components (adhesive layer 30, first outer layer 11, second outer layer 12, and first inner tube 20) can also be expressed as the relationship between the melting points of the materials forming each component. That is, in the balloon catheter 100 of this embodiment, the melting points of the forming materials for the four components increase in the order of adhesive layer 30, first outer layer 11, second outer layer 12, and first inner tube 20. For example, the melting point of the forming material for the adhesive layer 30 is 81°C, the melting point of the forming material for the first outer layer 11 is 170°C, the melting point of the forming material for the second outer layer 12 is 178°C, and the melting point of the forming material for the first inner tube 20 is 334°C.

[0039] In this embodiment, the melting points of the first inner layer tube 20 and the outer layer 10 (first outer layer 11 and second outer layer 12) are significantly different, making it impossible to weld the first inner layer tube 20 and the outer layer 10 together. Therefore, the first inner layer tube 20 and the outer layer 10 are bonded together by an adhesive layer 30. The second inner layer tube 40 is made of a material that can be welded to the outer layer 10 and is welded to the outer layer 10.

[0040] A-3. Method for manufacturing balloon catheter 100: Figures 5 to 7 are explanatory diagrams showing an example of a method for manufacturing the balloon catheter 100 in this embodiment. When manufacturing the balloon catheter 100, first, as shown in column A of Figure 5, the first inner tube 20 is prepared, and as shown in column B of Figure 5, the adhesive layer forming material 30X is placed on the outer surface of the first inner tube 20. The placement of the adhesive layer forming material 30X on the outer surface of the first inner tube 20 can be achieved, for example, by extrusion coating. Alternatively, the placement of the adhesive layer forming material 30X may be performed simultaneously with the fabrication of the first inner tube 20 by co-extrusion.

[0041] Next, as shown in column C of Figure 5, the precursor 100X is produced by covering the first inner layer tube 20 and the separately prepared second inner layer tube 40 with the forming material 10X of the outer layer 10. In this embodiment, the outer layer 10 is composed of a first outer layer 11 and a second outer layer 12, so the forming material 10X of the outer layer 10 is composed of the forming material of the first outer layer 11 and the forming material of the second outer layer 12.

[0042] Next, the precursor 100X is heated. This heating is performed at a temperature at which the forming material 30X of the adhesive layer 30 and the forming material 10X of the outer layer 10 melt. As shown in column D of Figure 5, this heating causes the forming material 10X of the outer layer 10 to melt and the outer layer 10 to be formed, and the forming material 30X of the adhesive layer 30 to melt and form an adhesive layer 30 that adheres the first inner layer tube 20 and the outer layer 10 together. At this time, the second inner layer tube 40 is welded to the outer layer 10. This heating may be performed on the entire precursor 100X at once, or it may be performed sequentially on the part of the precursor 100X that is composed of the forming material of the first outer layer 11 and the part that is composed of the forming material of the second outer layer 12. For example, heating may be performed on the part of the precursor 100X that is composed of the forming material of the first outer layer 11, and then on the part that is composed of the forming material of the second outer layer 12.

[0043] Next, as shown in column E of Figure 6, the tip of the first inner layer tube 20 (part P1 in the figure) is removed, and as shown in column F of Figure 6, a communication channel C1 extending radially from the inner circumferential surface at the tip of the first inner layer tube 20 to the outer circumferential surface of the outer layer 10 is formed, for example by laser processing.

[0044] Next, as shown in column G of Figure 7, the tip 50 is joined to the tip of the outer layer 10, for example by welding, and as shown in column H of Figure 7, the balloon 60 is joined to the outer layer 10 and the tip 50, for example by welding. A Y connector 80 is also attached to the base end of the outer layer 10. For example, a balloon catheter 100 with the above configuration is manufactured by the above manufacturing method.

[0045] A-4. Effects of the first embodiment: As described above, the balloon catheter 100 of this embodiment comprises a first inner tube 20, an outer layer 10, a balloon 60, and an adhesive layer 30. The outer layer 10 is a member that covers the outer circumferential surface of the first inner tube 20. The balloon 60 is a member that covers the outer circumferential surface of the outer layer 10. The internal space 61 of the balloon 60 is in communication with the lumen 21 of the first inner tube 20. The adhesive layer 30 is placed between the first inner tube 20 and the outer layer 10 to bond them together.

[0046] Thus, in the balloon catheter 100 of this embodiment, the lumen 21 of the first inner tube 20 communicates with the internal space 61 of the balloon 60 and functions as an expansion medium lumen L1. Furthermore, the first inner tube 20 is bonded to the outer layer 10 by an adhesive layer 30. Therefore, when negative pressure is generated in the expansion medium lumen L1 due to the discharge of the expansion medium through the expansion medium lumen L1, it is possible to suppress the first inner tube 20 from peeling off from the outer layer 10 and collapsing. Accordingly, with the balloon catheter 100 of this embodiment, it is possible to suppress the reduction in the cross-sectional area of ​​the expansion medium lumen L1 due to peeling and collapse of the first inner tube 20, and to achieve smooth discharge of the expansion medium through the expansion medium lumen L1.

[0047] Furthermore, in the balloon catheter 100 of this embodiment, the hardness of the adhesive layer 30 is lower than the hardness of at least a portion of the outer layer 10 and the hardness of at least a portion of the first inner tube 20. Therefore, the adhesive layer 30 can effectively adhere the first inner tube 20 to the outer layer 10. Accordingly, the balloon catheter 100 of this embodiment can effectively suppress the peeling of the first inner tube 20 from the outer layer 10, and enable smoother discharge of the expansion medium through the expansion medium lumen L1.

[0048] Furthermore, in the balloon catheter 100 of this embodiment, the hardness of the first inner tube 20 is higher than that of the outer layer 10. Therefore, when negative pressure is generated in the expansion medium lumen L1, the collapse of the first inner tube 20 can be effectively suppressed. Accordingly, the balloon catheter 100 of this embodiment can effectively suppress the collapse of the first inner tube 20, enabling smoother discharge of the expansion medium through the expansion medium lumen L1.

[0049] Furthermore, in the balloon catheter 100 of this embodiment, the outer layer 10 includes a first outer layer 11 and a second outer layer 12 positioned proximal to the first outer layer 11, with the hardness of the first outer layer 11 being lower than that of the second outer layer 12. According to the balloon catheter 100 of this embodiment, the tip portion of the balloon catheter 100 can be made relatively soft to improve its conformability to the lumen of the body, while the proximal portion of the balloon catheter 100 can be made relatively hard to improve its ability to be pushed in.

[0050] Furthermore, in the balloon catheter 100 of this embodiment, the hardness of the adhesive layer 30 is lower than the hardness of the first outer layer 11, the hardness of the second outer layer 12, and the hardness of the first inner tube 20. Therefore, the adhesive layer 30 can effectively adhere the first inner tube 20 to either the first outer layer 11 or the second outer layer 12. Accordingly, the balloon catheter 100 of this embodiment can effectively suppress the peeling of the first inner tube 20 from the outer layer 10, including the first outer layer 11 and the second outer layer 12, and enable smoother discharge of the expansion medium through the expansion medium lumen L1.

[0051] Furthermore, in the balloon catheter 100 of this embodiment, the hardness of the first inner tube 20 is higher than that of either the first outer layer 11 or the second outer layer 12. Therefore, when negative pressure is generated in the expansion medium lumen L1, the collapse of the first inner tube 20 can be more effectively suppressed. Accordingly, the balloon catheter 100 of this embodiment can more effectively suppress the collapse of the first inner tube 20, and can achieve smoother discharge of the expansion medium through the expansion medium lumen L1.

[0052] Furthermore, the manufacturing method for the balloon catheter 100 of this embodiment includes the steps of: preparing a first inner tube 20 on which a material 30X forming an adhesive layer 30 is arranged on its outer surface; producing a precursor 100X by covering the first inner tube 20 with a material 10X forming an outer layer 10; and forming an outer layer 10 by heating the precursor 100X to melt the material 10X forming the outer layer 10, and simultaneously forming an adhesive layer 30 between the first inner tube 20 and the outer layer 10 by melting the material 30X forming the adhesive layer 30. According to the manufacturing method for the balloon catheter 100 of this embodiment, a balloon catheter 100 in which the first inner tube 20 is bonded to the outer layer 10 by the adhesive layer 30 can be easily manufactured.

[0053] B. Second Embodiment: Figure 8 is an explanatory diagram showing the side view of the balloon catheter 100a in the second embodiment. In the following, for components of the balloon catheter 100a in the second embodiment that are the same as those of the balloon catheter 100 in the first embodiment described above, the same reference numerals are used, and their explanations will be omitted as appropriate.

[0054] In the balloon catheter 100a of the second embodiment, the outer layer 10a has a third outer layer 13 located towards the tip of the first outer layer 11, in addition to the first outer layer 11 and the second outer layer 12. The third outer layer 13 is connected to the tip of the first outer layer 11 so as to be substantially coaxial with the first outer layer 11.

[0055] Figure 9 is an explanatory diagram showing the hardness of each component constituting the balloon catheter 100a in the second embodiment. As shown in Figure 9, in the balloon catheter 100a of the second embodiment, the Shore hardness (A) of the adhesive layer 30 is 80, the Shore hardness (A) of the third outer layer 13 is 80, the Shore hardness (D) of the first outer layer 11 is 30, the Shore hardness (D) of the second outer layer 12 is 80, and the Shore hardness (D) of the first inner tube 20 is 2000. In other words, in the balloon catheter 100a of the second embodiment, the hardness of the above five components increases in the order of adhesive layer 30 and third outer layer 13, first outer layer 11, second outer layer 12, and first inner tube 20. Such a hardness relationship can be achieved, for example, by forming the adhesive layer 30 and the third outer layer 13 from urethane resin, the first outer layer 11 from a mixed material of urethane resin and nylon resin, the second outer layer 12 from nylon resin, and the first inner layer tube 20 from PEEK.

[0056] In the balloon catheter 100a of the second embodiment, the relationship of the hardness of each component is as described above, and therefore the following relationships (1) to (3) hold true. (1) The hardness of the adhesive layer 30 is lower than the hardness of at least a portion of the outer layer 10a and the hardness of at least a portion of the first inner layer tube 20. (2) The hardness of the first inner layer tube 20 is higher than the hardness of the outer layer 10a. (3) The hardness of the first outer layer 11 is lower than the hardness of the second outer layer 12. (4) The hardness of the third outer layer 13 is lower than that of the first outer layer 11.

[0057] The balloon catheter 100a of the second embodiment comprises a first inner tube 20, an outer layer 10a, a balloon 60, and an adhesive layer 30, similar to the balloon catheter 100 of the first embodiment described above. The outer layer 10a is a member that covers the outer circumferential surface of the first inner tube 20. The balloon 60 is a member that covers the outer circumferential surface of the outer layer 10a. The internal space 61 of the balloon 60 is in communication with the lumen 21 of the first inner tube 20. The adhesive layer 30 is placed between the first inner tube 20 and the outer layer 10a to bond them together. Therefore, according to the balloon catheter 100a of the second embodiment, similar to the balloon catheter 100 of the first embodiment described above, when negative pressure is generated in the expansion medium lumen L1 due to the discharge of the expansion medium through the expansion medium lumen L1, it is possible to suppress the first inner tube 20 from peeling off from the outer layer 10a and collapsing, and it is possible to suppress the reduction in the cross-sectional area of ​​the expansion medium lumen L1 due to the peeling and collapse of the first inner tube 20, thereby enabling smooth discharge of the expansion medium through the expansion medium lumen L1.

[0058] Furthermore, in the balloon catheter 100a of the second embodiment, the outer layer 10a includes a third outer layer 13, a first outer layer 11 positioned proximal to the third outer layer 13, and a second outer layer 12 positioned proximal to the first outer layer 11, wherein the hardness of the third outer layer 13 is lower than that of the first outer layer 11, and the hardness of the first outer layer 11 is lower than that of the second outer layer 12. Therefore, according to the balloon catheter 100a of the second embodiment, the tip portion of the balloon catheter 100a can be made relatively soft to improve conformability to the lumen of the body, while the proximal portion of the balloon catheter 100a can be made relatively hard to improve pushability, and furthermore, kink resistance can be improved by reducing the rigidity gap along the length of the balloon catheter 100a.

[0059] C. Variant: The technologies disclosed herein are not limited to the embodiments described above and can be modified in various forms without departing from their essence, for example, the following modifications are possible.

[0060] The configuration of the balloon catheter 100 in the above embodiment is merely an example and can be modified in various ways. For example, in the above embodiment, the internal space 61 of the balloon 60 and the lumen 21 (expansion medium lumen L1) of the first inner tube 20 are in communication via a communication channel C1, but as shown in the modified example in Figure 10, the internal space 61 of the balloon 60 and the lumen 21 of the first inner tube 20 may be in direct communication. In the modified example shown in Figure 10, at the tip of the first inner tube 20, the lumen 21 of the first inner tube 20 is in communication with the internal space 61 of the balloon 60.

[0061] In the above embodiment, the outer layer 10 is composed of a first outer layer 11 and a second outer layer 12 (or a first outer layer 11, a second outer layer 12, and a third outer layer 13) that are aligned in the stretching direction and have different hardnesses. However, the outer layer 10 may be composed of four or more parts with different hardnesses, or the hardness may be uniform throughout its entire length. Furthermore, the outer diameter and inner diameter of each part of the outer layer 10 in the stretching direction may be uniform or vary.

[0062] In the above embodiment, the first inner layer tube 20 has a uniform hardness throughout its entire length, but the first inner layer tube 20 may be composed of multiple parts that are aligned in the extension direction and have different hardnesses from each other. Furthermore, the outer diameter and inner diameter of each part of the first inner layer tube 20 in the extension direction may be uniform or vary.

[0063] The forming materials for each component in the above embodiment are merely examples and can be modified in various ways. For example, in the above embodiment, components such as the outer layer 10, the first inner layer tube 20, the second inner layer tube 40, and the tip 50 may be formed from materials other than resin (e.g., metal, carbon fiber, ceramics, etc.).

[0064] The hardness values ​​of each component and their relative hardness levels in the above embodiments are merely examples and can be modified in various ways. For example, in the first embodiment, the hardness of the first outer layer 11 may be lower than that of the second outer layer 12, but the hardness of the first outer layer 11 may be higher than that of the second outer layer 12. Similarly, in the second embodiment, the hardness of the third outer layer 13 may be lower than that of the first outer layer 11, and the hardness of the first outer layer 11 may be lower than that of the second outer layer 12, but the hardness of the third outer layer 13 may be higher than that of the first outer layer 11, or the hardness of the first outer layer 11 may be higher than that of the second outer layer 12. Furthermore, in the first embodiment described above, the hardness of the adhesive layer 30 is lower than the hardness of the first outer layer 11 and the hardness of the second outer layer 12, but the hardness of the adhesive layer 30 may be lower than one of the hardness of the first outer layer 11 and the hardness of the second outer layer 12, and the same as or higher than the other. Similarly, in the second embodiment described above, the hardness of the adhesive layer 30 is the same as the third outer layer 13 and lower than the hardness of the first outer layer 11 and the hardness of the second outer layer 12, but the hardness of the adhesive layer 30 may be lower than one of the hardness of the first outer layer 11 and the hardness of the second outer layer 12, and the same as or higher than the other, or it may be higher than the hardness of the third outer layer 13.

[0065] The method for manufacturing the balloon catheter 100 in the above embodiment is merely an example and can be modified in various ways. For example, in the above embodiment, the tip 50 is joined after the removal of the tip of the first inner tube 20 and the formation of the communication channel C1, but the tip 50 may be joined before the removal of the tip of the first inner tube 20 and the formation of the communication channel C1.

[0066] In the above embodiment, the balloon catheter 100 is a so-called over-the-wire type balloon catheter, but the technology disclosed herein is also applicable to a so-called rapid exchange (RX) type balloon catheter. Furthermore, in the above embodiment, the balloon catheter 100 is a balloon-assisted guiding catheter having a device lumen L2 for guiding a device, but the technology disclosed herein is also applicable to a balloon catheter that does not have a device lumen for guiding devices other than the guidewire, but has a guidewire lumen through which the guidewire is inserted. [Explanation of Symbols]

[0067] 10: Outer layer 11: First outer layer 12: Second outer layer 13: Third outer layer 20: First inner tube 21: Lumen 30: Adhesive layer 40: Second inner tube 41: Lumen 50: Tip 51: Lumen 60: Balloon 61: Internal space 80: Y connector 81: Expansion medium port 82: Device port 100: Balloon catheter C1: Communication channel L1: Expansion medium lumen L2: Device lumen

Claims

1. It is a balloon catheter, The first inner layer tube, The second inner layer tube, An outer layer covering the outer surface of the first inner layer tube and the outer surface of the second inner layer tube, A balloon covering the outer surface of the outer layer, wherein the internal space of the balloon and the lumen of the first inner layer tube are in communication, An adhesive layer disposed between the first inner layer tube and the outer layer, Equipped with, The hardness of the adhesive layer is lower than the hardness of at least a portion of the outer layer and the hardness of at least a portion of the first inner tube. Balloon catheter.

2. A balloon catheter according to claim 1, The hardness of the first inner layer tube is higher than the hardness of the outer layer. Balloon catheter.

3. A balloon catheter according to claim 1 or claim 2, The aforementioned outer layer is The first outer layer and, A second outer layer is positioned on the proximal end side of the first outer layer, Includes, The hardness of the first outer layer is lower than the hardness of the second outer layer. Balloon catheter.

4. A balloon catheter according to claim 3, The hardness of the adhesive layer is lower than the hardness of the first outer layer, the hardness of the second outer layer, and the hardness of the first inner tube. Balloon catheter.

5. A balloon catheter according to claim 3 or claim 4, The hardness of the first inner layer tube is higher than the hardness of the first outer layer and the hardness of the second outer layer. Balloon catheter.

6. A balloon catheter according to any one of claims 1 to 5, The outer diameter of the first inner layer tube is smaller than the outer diameter of the second inner layer tube. Balloon catheter.

7. A balloon catheter according to any one of claims 1 to 6, The second inner layer tube is directly joined to the outer layer. Balloon catheter.

8. A balloon catheter according to any one of claims 1 to 7, The tip opening of the first inner layer tube is closed by the outer layer. The lumen of the first inner tube communicates with the internal space of the balloon through a radially extending communication hole. Balloon catheter.

9. A method for manufacturing a balloon catheter comprising: a first inner layer tube; a second inner layer tube; an outer layer covering the outer circumferential surface of the first inner layer tube and the outer circumferential surface of the second inner layer tube; and a balloon covering the outer circumferential surface of the outer layer, wherein the inside of the balloon and the lumen of the first inner layer tube are in communication; A step of preparing the first inner layer tube, on which an adhesive layer forming material is placed on the outer surface, A step of producing a precursor by covering the first inner layer tube with the outer layer forming material, The process involves heating the precursor to melt the outer layer forming material, thereby forming the outer layer, and melting the adhesive layer forming material to form the adhesive layer between the first inner tube and the outer layer. Equipped with, The hardness of the adhesive layer is lower than the hardness of at least a portion of the outer layer and the hardness of at least a portion of the first inner tube. A method for manufacturing a balloon catheter.

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