Balloon catheter

Abstract

To provide a balloon catheter capable of preventing separation of a distal end cylindrical portion of a balloon when the balloon catheter passes through a curved or branched blood vessel.SOLUTION: A balloon catheter includes a cylindrical member 160, and a balloon 140 disposed on a proximal side of the cylindrical member 160, the balloon including a distal side cylindrical portion 141, an actuation portion 143 having a space inflatable in a cylindrical shape, and a distal side tapered portion 142 connected between the distal side cylindrical portion 141 and the actuation portion 143, wherein, in an axial cross-sectional view, a most distal end 141a of the distal side cylindrical portion 141 is positioned radially inside relative to an outer surface 161 of the cylindrical member 160, and at least the most distal end 141a of the distal side cylindrical portion 141 and a part of a radially inside inner surface 141c that is radially inside the most distal end 141a are positioned in contact with the cylindrical member 160.SELECTED DRAWING: Figure 3A

Description

[Technical Field]

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

[0002] When various medical procedures are performed inside a biological lumen such as a blood vessel, a balloon catheter (e.g., Patent Document 1 below) equipped with a balloon for expanding a lesion in the biological lumen is sometimes used. Generally, a balloon catheter includes a long shaft and a cylindrical member such as a soft tip disposed at the distal end of the shaft. The distal neck portion (distal cylindrical portion) of the balloon is joined to the outer circumferential surface of the cylindrical member and the shaft inner tube (first tubular body). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-160536 Summary of the Invention [Problem to be solved by the invention]

[0004] The balloon catheter disclosed in Patent Document 1 has a distal tubular portion of the balloon bonded to the outer peripheral surfaces of a cylindrical member and a first tubular body. When a balloon catheter is inserted into a curved or branched blood vessel, it attempts to bend to follow the shape of the blood vessel. When the balloon of the balloon catheter attempts to bend to follow the shape of the blood vessel, the fused portion between the cylindrical member and the distal tubular portion may peel off. Peeling off of the distal tubular portion of the balloon can cause problems such as reduced blood vessel passage, and therefore must be prevented as much as possible.

[0005] The present invention has been made in consideration of the above-mentioned problems, and specifically aims to provide a balloon catheter that can suppress detachment of the distal tubular portion of the balloon when passing through a curved or branched blood vessel. [Means for solving the problem]

[0006] The above object of the present invention can be achieved by any one of the following means (1) to (12).

[0007] (1) A balloon catheter comprising: a cylindrical member; and a balloon disposed on the base end side of the cylindrical member, the balloon including a distal tubular portion, an actuating portion having a cylindrically expandable space, and a distal tapered portion connected between the distal tubular portion and the actuating portion, wherein, in an axial cross-sectional view, the most distal end of the distal tubular portion is located radially inward relative to the outer surface of the cylindrical member, and at least the most distal end and a portion of the radially inner inner surface radially inward of the most distal end of the distal tubular portion are located in contact with the cylindrical member.

[0008] (2) In the balloon catheter described in (1) above, in an axial cross-sectional view, the cylindrical member includes a boundary portion that covers and continuously contacts the tip portion, which has the most distal end of the tip-side tubular portion, a radially outer outer surface radially outward from the most distal end, and the radially inner inner surface.

[0009] (3) The balloon catheter according to (2) above, wherein the boundary portion includes a curved portion that continues in a curved shape through the most distal end of the distal tubular portion.

[0010] The balloon catheter according to (1) above, wherein, in an axial cross-sectional view, the cylindrical member includes a curved boundary portion that covers and continuously contacts the most distal end of the distal tubular portion and the distal end of the outer surface radially outward from the most distal end, and the distance between the boundary portion and the outer surface in the radial direction decreases in accordance with the curved shape of the boundary portion, and terminates at the proximal end of the outer surface of the cylindrical member.

[0011] (5) A balloon catheter according to any one of (1) to (4) above, having a first tubular body arranged on the base end side of the cylindrical member, and the space portion being formed by the outer surface of the first tubular body and the inner surface of the working portion.

[0012] (6) A balloon catheter as described in (5) above, wherein, in an axial cross-sectional view, the tip end portion of the first tubular body and the tip end portion of the tip-side tubular portion form a clamping portion that clamps a portion of the cylindrical member.

[0013] (7) The balloon catheter according to (5) or (6) above, wherein the distal end of the first tubular body is located distal to the distal end of the distal-side tubular portion.

[0014] (8) The balloon catheter according to (5) or (6) above, wherein the distal end of the distal tubular portion is located distally of the distal end of the first tubular body.

[0015] (9) A balloon catheter comprising: a cylindrical member; and a balloon arranged on the base end side of the cylindrical member, the balloon including a distal tubular portion and an actuating portion having an expandable space portion, wherein, in an axial cross-sectional view, the distal end of the distal tubular portion is formed in a tongue shape with a convex axial tip side, and the cylindrical member tightly covers the tongue-shaped distal end on the radial inside and outside.

[0016] (10) A balloon catheter as described in (9) above, which has a first tubular body arranged on the base end side of the cylindrical member, and the space portion is formed by the outer surface of the first tubular body and the inner surface of the working portion.

[0017] (11) In an axial cross-sectional view, the distal end portion of the first tubular body and the distal end portion of the distal-side tubular portion form a clamping portion that clamps a portion of the cylindrical member.

[0018] (12) A balloon catheter including a cylindrical member and a balloon disposed on the base end side of the cylindrical member, the balloon including a distal tubular portion, an operating section having a tubularly expandable space, and a distal tapered portion connected between the distal tubular portion and the operating section, wherein, in an axial cross-sectional view, the cylindrical member has an outer surface and an outer surface proximal end that is the proximal end of the outer surface, the distal tubular portion has an outer surface and a distal end, the distal end of the distal tubular portion is located radially inward relative to the outer surface of the cylindrical member, and the portion extending from the outer surface of the cylindrical member via the outer surface proximal end to the outer surface of the distal tubular portion is located on a straight line or a curved line that is convex radially outward as the outer surface of the balloon catheter. [Effects of the Invention]

[0019] According to one embodiment of the present invention, the balloon catheter has sufficient bonding strength between the cylindrical member, the shaft, and the distal tubular portion of the balloon, thereby preventing the distal tubular portion of the balloon from peeling off when passing through a curved or branched blood vessel. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a diagram showing the overall configuration of a balloon catheter according to a first embodiment. FIG. [Figure 2] 1 is an axial cross-sectional view of the vicinity of the distal end of a balloon catheter according to a first embodiment. FIG. [Figure 3A] FIG. 3 is a partial enlarged view of part A shown in FIG. 2. [Figure 3B] FIG. 2 is a partially enlarged view of the periphery of the distal end side cylindrical portion. [Figure 3C] FIG. 3B is a partially enlarged view of part B shown in FIG. 3A. [Figure 4A] FIG. 2 is a diagram illustrating the method (step A) for manufacturing the balloon catheter according to the first embodiment. [Figure 4B] FIG. 4 is a view for explaining the method (step B) for manufacturing the balloon catheter according to the first embodiment. [Figure 4C]FIG. 4 is a view for explaining the method (step C) for manufacturing the balloon catheter according to the first embodiment. [Figure 5A] FIG. 10 is a view showing the fusion position of the distal tubular portion of the balloon in a state in which the cylindrical member and the first tubular body are connected. [Figure 5B] FIG. 5B is a partial cross-sectional view showing the state after the balloon in FIG. 5A has been fused. [Figure 6A] FIG. 10 is a view showing the fusion position of the distal tubular portion of the balloon in a state in which the cylindrical member and the first tubular body are connected. [Figure 6B] FIG. 6B is a partial cross-sectional view showing the state after the balloon in FIG. 6A has been fused. [Figure 7A] 10 is a diagram showing the fusion position of the distal end tubular portion of the balloon when the cylindrical member, the first tubular body, and the balloon are fused together at the same time. FIG. [Figure 7B] FIG. 7B is a partial cross-sectional view showing the state after the balloon in FIG. 7A has been fused. [Figure 7C] FIG. 7B is a partial cross-sectional view showing another state after the balloon in FIG. 7A has been fused. [Figure 8A] 10 is a diagram showing the fusion position of the distal end tubular portion of the balloon when the cylindrical member, the first tubular body, and the balloon are fused together at the same time. FIG. [Figure 8B] FIG. 8B is a partial cross-sectional view showing the state after the balloon in FIG. 8A has been fused. [Figure 8C] FIG. 8B is a partial cross-sectional view showing another state after the balloon in FIG. 8A has been fused. [Figure 9A] 10 is a diagram showing the fusion position of the distal end tubular portion of the balloon when the cylindrical member, the first tubular body, and the balloon are fused together at the same time. FIG. [Figure 9B] FIG. 9B is a partial cross-sectional view showing the state after the balloon in FIG. 9A has been fused. [Figure 10] FIG. 10 is a partial cross-sectional view of the vicinity of the distal end of a balloon catheter according to a second embodiment. [Figure 11] FIG. 1A is a partial cross-sectional view of the vicinity of the tip portion showing a modified example of the balloon catheter according to the first embodiment, and FIG. 1B is a partial cross-sectional view of the vicinity of the tip portion showing a modified example of the balloon catheter according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments shown here are merely examples for embodying the technical idea of the present invention and are not intended to limit the present invention. Furthermore, all other embodiments, examples, and operational techniques that can be conceived by those skilled in the art without departing from the spirit of the present invention are included in the scope and spirit of the present invention, as well as in the scope of the inventions set forth in the claims and their equivalents.

[0022] Furthermore, for the convenience of illustration and ease of understanding, the drawings attached to this specification may be represented schematically with the scale, aspect ratio, shape, etc. appropriately changed from the actual product, but these are merely examples and do not limit the interpretation of the present invention.

[0023] In the following description, when ordinal numbers such as "first" and "second" are used, they are used for convenience and do not define any particular order unless otherwise specified. In this specification, the term "X to Y" indicating a range includes X and Y and means "greater than or equal to X and less than or equal to Y."

[0024] The configuration of the balloon catheter 100 according to the first embodiment will be described.

[0025] As shown in Figure 1 or Figure 2, the balloon catheter 100 is a medical device that expands a lesion such as a stenosis formed in a biological lumen by expanding a balloon 140 located at the tip of the shaft 110 at the lesion, thereby treating the lesion.

[0026] The balloon catheter 100 can be configured as a PTCA treatment balloon catheter used, for example, to widen a lesion in a coronary artery. However, the balloon catheter 100 can also be configured as one used for the purpose of treating and improving lesions formed in biological organs, such as other blood vessels, bile ducts, tracheas, esophagus, other digestive tracts, urethras, ear and nose cavities, and other organs. It can also be used as a catheter for carrying a stent attached to the balloon 140 to the lesion.

[0027] In the following description, the side on which the balloon 140 is disposed will be referred to as the "distal side" of the balloon catheter 100, and the side on which the hub 150 is disposed will be referred to as the "proximal side" of the balloon catheter 100. As shown in FIG. 2 , the direction in which the central axis O of the shaft 110 extends will be referred to as the "axial direction." The direction perpendicular to the central axis O will be referred to as the "radial direction." Furthermore, unless otherwise specified, the "distal portion" refers to a certain range including the distal end (the most distal end) and its surroundings, and the "proximal end" refers to a certain range including the proximal end (the most proximal end) and its surroundings.

[0028] The balloon catheter 100 is configured as a so-called "rapid exchange catheter device" in which a guidewire port 111 through which a guidewire G is led out is provided near the distal end of the shaft 110. The balloon catheter 100 can also be configured as a so-called "over-the-wire catheter device" in which a guidewire lumen 121 is formed to extend from the distal end to the proximal end of the shaft 110.

[0029] 1, the balloon catheter 100 can be provided with a hub 150 at the proximal end of the shaft 110. The hub 150 is configured to be connectable to a connector (Y connector) known in the medical field, and can be connected in a liquid-tight and airtight manner via the connector to a supply device (not shown) such as an indeflator for supplying a pressurized medium.

[0030] 2, the shaft 110 has a first tubular body 120 serving as an inner tube in which a guidewire lumen 121 through which a guidewire G is inserted is formed, and a second tubular body 130 serving as an outer tube in which a pressurized medium lumen 131 through which a pressurized medium can flow is formed between the first tubular body 120 and the second tubular body 130. The shaft 110 has a double-tube structure in which the first tubular body 120 and the second tubular body 130 are concentrically arranged by inserting the first tubular body 120 into the second tubular body 130.

[0031] A balloon 140 is joined to the distal end of the balloon catheter 100 in a liquid-tight and air-tight manner.

[0032] A cylindrical member 160 can be attached to the tip of the first tubular body 120. The cylindrical member 160 has a function of, for example, suppressing damage to a biological organ (such as the inner wall of a blood vessel) when the tip of the balloon catheter 100 comes into contact with the biological organ. Such a cylindrical member 160 can be, for example, a soft tip made of a resin material that is more flexible than the first tubular body 120.

[0033] The first tubular body 120 may be provided with a radiopaque marker portion 170. The radiopaque marker portion 170 may be disposed, for example, at a position on the first tubular body 120 that indicates the boundary with the distal end side of the balloon 140, and at a position on the first tubular body 120 that indicates the boundary with the proximal end side of the balloon 140.

[0034] Examples of materials that can be used to form the first tubular body 120 and the second tubular body 130 include polyolefins such as polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer, thermoplastic resins such as soft polyvinyl chloride, various rubbers such as silicone rubber and latex rubber, various elastomers such as polyurethane elastomer, polyamide elastomer, and polyester elastomer, and crystalline plastics such as polyamide, crystalline polyethylene, and crystalline polypropylene. These materials can also be blended with antithrombotic substances such as heparin, prostaglandin, urokinase, and arginine derivatives to form antithrombotic materials.

[0035] The balloon 140 is disposed on the distal end side of the shaft 110 (the distal end side of the first tubular body 120).

[0036] The balloon 140 has a distal tubular portion 141, a distal tapered portion 142 arranged adjacent to the base end of the distal tubular portion 141, an operating portion 143 arranged adjacent to the base end of the distal tapered portion 142 and capable of expanding and contracting by a pressurized medium, a proximal tapered portion 144 arranged adjacent to the base end of the operating portion 143, and a proximal tubular portion 145 arranged adjacent to the base end of the proximal tapered portion 144.

[0037] The balloon 140 has a tip-side tubular portion 141 on the tip side fused to the first tubular body 120 and the cylindrical member 160, and a base-side tubular portion 145 on the base side fused to the second tubular body 130.

[0038] The balloon 140 has a space 140a between itself and the first tubular body 120, through which a pressurized medium can flow. The space 140a is formed by the space between the inner surface of the working portion 143 and the outer surface of the first tubular body 120. When a pressurized medium flows into the space 140a, the working portion 143 expands into a cylindrical shape, and when the pressurized medium flows out of the space 140a, the working portion 143 contracts. Alternative embodiments of the working portion 143 include those in which the working portion expands into a spherical or spindle shape. In this case, tapered portions may or may not be provided at the distal and proximal ends of the working portion, depending on the purpose and function of the balloon. When the balloon 140 expands, the balloon catheter 100 presses a portion of the balloon 140 against a lesion formed in a biological lumen, thereby expanding and dilating the lesion. Furthermore, in a catheter with a stent attached to a deflated balloon 140, the stent is placed by expanding the balloon 140, maintaining the dilated state of the lesion.

[0039] A pressurized medium (e.g., a fluid such as physiological saline or a contrast agent) used to inflate the balloon 140 can be flowed into the pressurized medium lumen 131 of the shaft 110 via the internal space (lumen) of the hub 150. The pressurized medium is supplied to the space 140a of the balloon 140 via the pressurized medium lumen 131.

[0040] The balloon 140 may be made of, for example, an organic polymer material. Specifically, polymer materials such as polyolefins (e.g., polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of these), polyvinyl chloride, polyamides (e.g., nylons such as nylon 6, nylon 6·6, nylon 6·10, and nylon 12), polyamide elastomers, polyurethanes, polyurethane elastomers, polyimides, and fluororesins, or mixtures of these, or elastic resins such as two or more of the above polymer materials, may be used. The balloon 140 may have a single-layer structure or a multilayer structure including at least two layers, an inner layer and an outer layer. In a multilayer structure, the inner and outer layers may be made of the same or different materials.

[0041] A coating can be formed on the outer surface of the balloon 140. The coating can be, for example, a hydrophilic coating layer that improves the sliding properties of the balloon 140, or a drug coating layer that contains a predetermined drug. There are no particular limitations on the specific materials that can be used to form the hydrophilic coating layer or drug coating layer.

[0042] As shown in FIG. 3A, the balloon catheter 100 has the following characteristic structure to prevent the distal tubular portion 141 from peeling off (turning up) when inserted into a curved or branched blood vessel.

[0043] As shown in Fig. 3A, in a cross section taken along the axial direction (axial cross section), the balloon catheter 100 has a distal end 141a of the distal end tubular portion 141 located within the cylindrical member 160, radially inward of the outer surface 161 of the cylindrical member 160. In the balloon catheter 100, the distal end 141a of the distal end tubular portion 141 is located radially inward of the outer surface 161 of the cylindrical member 160 over the entire circumferential direction in the axial direction, and at least the distal end 141a and a portion of the radially inner surface 141c of the distal end tubular portion 141 that is radially inward of the distal end 141a are located in contact with the cylindrical member 160. The structure shown in Fig. 3A can be formed by locally laser fusing the shaft 110 (first tubular body 120), the balloon 140, and the cylindrical member 160 while they are positioned in predetermined positions.

[0044] In the balloon catheter 100, as shown in Fig. 3A, the distal end tubular portion 141 has a distal end 141d including a distal end 141a of the distal end tubular portion 141, an outer surface 141b radially outward from the distal end 141a, and an inner surface 141c radially inward from the distal end 141a. The cylindrical member 160 has a boundary portion 162 that covers and continuously contacts the distal end 141a, the radially outward outer surface 141b, and the radially inner inner surface 141c. As shown in Fig. 3A, the radially outer outer surface 141b is the surface radially outward (upper side in Fig. 3A) from the distal end 141a of the distal end 141d of the distal end tubular portion 141 when the boundary is taken as the boundary. As shown in Fig. 3A, in an axial cross-sectional view, the radially inner inner surface 141c is a surface that is radially inward (lower in Fig. 3A) from the most distal end 141a of the distal end portion 141d of the distal end-side cylindrical portion 141, with the most distal end 141a being the boundary. As shown in Fig. 3A, the radially inner inner surface 141c has a portion that contacts the cylindrical member 160. Furthermore, the base end side has a portion that contacts the distal end side (first tubular body 120) of the shaft 110. A boundary portion 162 with the radially outer outer surface 141b is curved so that the radially outer side is convex. As shown in Figures 3B(1) and (2), at a boundary 162 between the radially outer outer surface 141b of the distal-side tubular portion 141 and the cylindrical member 160, the distance between the radially outer outer surface 141b and the outer surface 161 in the radial direction decreases according to the curved shape of the boundary 162, and terminates at the outer surface proximal end 160f0 of the cylindrical member 160 (see the double-headed arrow in Figure 3B(1)). The radial distance between the boundary 162 and the outer surface 161 decreases at a decreasing rate as it progresses toward the axial proximal end. The outer surface proximal end 160f0 is located on the outer surface of the balloon catheter 100.

[0045] The portion extending from the outer surface 161 of the cylindrical member 160, via the outer surface base end 160f0, to the outer surface 141b1 of the distal tubular portion 141 is disposed on a straight line or a curved line convex radially outward, as the outer surface of the balloon catheter 100. As shown in Figures 3A and 3B(1), the outer surface of the balloon catheter 100 extending from the outer surface 161 of the cylindrical member 160, via the outer surface base end 160f0, to the outer surface 141b1 of the distal tubular portion 141 is curved radially outward, and the outer surface 161 of the cylindrical member 160 and the outer surface 141b1 of the distal tubular portion 141 do not intersect with the tangent line T passing through the outer surface base end 160f0. In other words, unless there is an inflection point facing radially outward on the axial tip side of the outer surface 161 of the cylindrical member 160 or on the axial base side of the outer surface 141b1 of the tip-side tubular portion 141, the tangent line T and the outer surface 161, and the tangent line T and the outer surface 141b1, will move radially apart as they move axially away from the outer surface base end 160f0. Figure 3B(2) shows an aspect in which the portion extending from the outer surface 161 of the cylindrical member 160, via the outer surface base end 160f0, to the outer surface 141b1 of the tip-side tubular portion 141 is arranged on a straight line as the outer surface of the balloon catheter 100. In other words, unless there is an inflection point facing radially outward on the axial tip side of the outer surface 161 of the cylindrical member 160 or on the axial base end of the outer surface 141b1 of the tip-side tubular portion 141, the above-mentioned straight line will not intersect with the outer surface 161 or the outer surface 141b1.

[0046] 3A, the balloon catheter 100 is arranged so that the distal end 141d of the distal end-side tubular portion 141 and the distal end 122 of the first tubular body 120 are in contact with each other in the radial direction in a cross-sectional view in the axial direction. In other words, the distal end 141d of the distal end-side tubular portion 141 and the distal end 122 of the first tubular body 120 are fused together while maintaining a boundary therebetween in the radial direction.

[0047] 3A, in the balloon catheter 100, the proximal end 160e of the cylindrical member 160 is arranged in contact with the distal end 141d of the distal end side cylindrical portion 141 and the distal end 122 of the first tubular body 120. Specifically, the distal end 141d of the distal end side cylindrical portion 141 and the distal end 122 of the first tubular body 120 are arranged to fit into the proximal end 160e of the cylindrical member 160. A distal end side cylindrical body proximal end 160f1 of the cylindrical member 160 is located between the distal end 141d of the distal end side cylindrical portion 141 and the distal end 122 of the first tubular body 120. The distal end 141d of the distal end side cylindrical portion 141 and the distal end 122 of the first tubular body 120 are each formed in a tongue shape with a convex distal end relative to the proximal end 160e of the cylindrical member 160. A guidewire lumen side base end 160f2 of the base end portion 160e of the cylindrical member 160 is located along the surface of the guidewire lumen 121 and is located axially closer to the base end than the forefront 122a of the tip portion 122 of the first tubular body 120. The forefront 141a of the tip-side cylindrical portion 141 is located axially closer to the tip end than the forefront 122a of the first tubular body 120.

[0048] The tip end 141d of the tip-side cylindrical portion 141 is formed in a tongue shape with the axial tip end side convex when viewed in axial cross section, and furthermore, the cylindrical member 160 tightly covers the tongue-shaped tip end 141d on the radial inside and outside.

[0049] As shown in FIG. 3A , the cylindrical member 160 has a boundary 162 at its proximal end, which is the boundary with the distal tubular portion 141. In FIG. 3A , the boundary 162 is indicated by a thick dotted line for ease of understanding the drawing, but in reality, it coincides with the outline of the cylindrical member 160. The boundary 162 is the contact portion between the cylindrical member 160 and the distal tubular portion 141 after fusion, and has a shape that wraps around and continuously contacts at least the distal end 141d along the outer shape of the distal end 141d. Therefore, the boundary 162 includes a straight portion and / or a curved portion in an axial cross-sectional view. From the viewpoints of the bendability of the cylindrical member 160 and its ability to follow the guidewire G, it is preferable that the boundary 162 be configured to include a curved portion that continues in a curved line through the distal end 141a as shown in FIG. 3A .

[0050] The operation of the embodiment shown in FIG. 3A will be described. When the balloon catheter 100 is inserted along a curved blood vessel or guidewire, tensile stress occurs on the outside of the curve and compressive stress occurs on the inside. In the balloon catheter shown in FIG. 3A, the angle at intersection X where the parallel line of the central axis O intersects with the boundary portion 162 decreases radially outward, resulting in a decrease in stress perpendicular to intersection X of the boundary portion 162. In reality, tensile stress increases with increasing radial outward movement. However, assuming that the force F acting along the central axis O remains constant regardless of the distance from the central axis O to the outside, as shown in FIG. 3B, the perpendicular component V2 to the tangent to intersection X2 of the boundary portion 162 near the outer surface 161 is smaller than the perpendicular component V1 to the tangent to intersection X1 of the boundary portion 162 near the leading edge 141a of the distal end tubular portion 141. This perpendicular component is a major factor in the force that detaches the distal end tubular portion 141 from the cylindrical member 160. Furthermore, when boundary portion 162 is configured in a curved shape that is convex radially outward as shown in Fig. 3A, unlike a linear boundary portion, vertical component V shown in Fig. 3B becomes extremely small near outer surface 161. As a result, even if cylindrical member 160 is bent, tip-side tubular portion 141 is unlikely to curl up from cylindrical member 160.

[0051] The balloon catheter 100 has a configuration in which the leading end 141a of the tip-side tubular portion 141 is located radially inward relative to the outer surface 161 of the cylindrical member 160, thereby increasing the bonding area of the tip-side tubular portion 141 to the cylindrical member 160. Furthermore, the tip end 141d of the tip-side tubular portion 141 is formed so as to fit into the thick portion of the cylindrical member 160 after fusion, so that the connection with the cylindrical member 160 is maintained firmly even if the balloon 100 bends to follow the shape of a blood vessel or a guidewire. Therefore, the balloon catheter 100 can improve the bonding strength between the cylindrical member 160 and the balloon 140, thereby preventing the tip end 141d of the balloon 140 from peeling off.

[0052] Furthermore, the balloon catheter 100 has a configuration in which the cylindrical member 160 includes a boundary portion 162 that covers and continuously contacts the distal end portion 141d, which has the distal end 141a of the distal-side tubular portion 141, the radially outer outer surface 141b radially outward from the distal end 141a, and the radially inner inner surface 141c radially inward from the distal end 141a. This increases the proportion of the distal-side tubular portion 141 that is fused to the cylindrical member 160 and decreases the proportion of the fused portion that is fused to other members. This allows the balloon catheter 100 to more easily utilize the bending characteristics of the cylindrical member 160. For example, if the cylindrical member 160 is made of a highly flexible material, the flexibility of the cylindrical member 160 is improved, reducing snagging and allowing the cylindrical member 160 to more easily conform to the curved or branched shape of a blood vessel.

[0053] Furthermore, if the balloon catheter 100 is configured such that the boundary portion 162, which is the fused portion (contact portion) between the distal tubular portion 141 and the cylindrical member 160, includes a curved portion that continues in a curved line through the most distal end 141a of the distal tubular portion 141, the peeling force caused by deformation during blood vessel tracking is smallest at the outer surface. This further enhances the peeling prevention effect of the distal end 141d of the balloon 140. Furthermore, since partial stress concentration at the boundary portion 162 due to deformation during blood vessel tracking can be suppressed, the peeling prevention effect of the distal end 141d of the balloon 140 can be further enhanced.

[0054] Next, a preferred embodiment of a method for manufacturing the balloon catheter 100 will be described.

[0055] 4A to 4C show steps for joining the shaft 110, the balloon 140, and the cylindrical member 160 in the method for manufacturing the balloon catheter 100. Note that the method for manufacturing the balloon catheter 100 may include steps other than those described below.

[0056] 4A to 4C, manufacturing apparatus 200 used to perform the joining process on balloon catheter 100 includes elastic bodies 210 that clamp the objects to be joined to prevent misalignment during joining, and an irradiation unit 220 that irradiates the objects to be joined with laser light L. In addition to the above-described configuration, manufacturing apparatus 200 can be configured by appropriately installing various devices required in the manufacturing process, such as an operation unit and a display unit (not shown).

[0057] The elastic body 210 is laser light transmissive, and specific examples of the material of the elastic body 210 include silicone rubber and fluororubber. By using the elastic body 210, the elastic body 210 is elastically deformed in the radial direction when pressurized by the pressurizing means, making it possible to maintain contact between the shaft 110, the balloon 140, and the cylindrical member 160, and to efficiently bond them. Furthermore, because the elastic body 210 is laser light transmissive, it does not thermally shrink due to the laser light L, and therefore can be reused.

[0058] The irradiation unit 220 irradiates laser light L with a wavelength that generates heat in the fused portion through radiant heating. The spot diameter of the laser light L can be set to φ0.1 mm to φ10 mm, and the wavelength of the laser light L can be set to 800 nm to 10,000 nm. Examples of laser light L that can be used include a fiber laser (wavelength 1070 nm), a YAG laser (wavelength 1064 nm), and a laser diode (808 nm, 840 nm, 940 nm). When fusing members containing a laser-absorbent material, the wavelength can be selected from 800 nm to 5,000 nm, preferably 900 nm to 2,300 nm. When fusing transparent members together or a member containing a laser-absorbent material and a transparent member, the wavelength can be selected from 1,300 nm to 2,500 nm, preferably 1,500 nm to 2,300 nm. The laser light L is generally irradiated in a direction perpendicular to the axial direction of the workpiece. The laser light L may be irradiated at an angle that is appropriately changed depending on the object to be processed.

[0059] The balloon catheter 100 is manufactured by joining the shaft 110, the balloon 140, and the cylindrical member 160 together in a manufacturing apparatus 200. Specifically, the manufacturing process preferably includes the following steps: inserting the first tubular body 120 of the shaft 110, the distal cylindrical portion 141 of the balloon 140, and the cylindrical member 160 into the hollow portion 211 of the elastic body 210 (step (A)), pressurizing the elastic body 210 radially inward and irradiating it with a laser to heat it (step (B)), releasing the pressure, and removing the fused (joined) balloon catheter 100 (step (C)).

[0060] (Process (A)) In step (A), as shown in FIG. 4A , the distal tubular portion 141 of the balloon 140 is positioned so as to be fused to the pre-joined cylindrical member 160 and first tubular body 120 at a predetermined fusion position. For example, the positioning can be performed while the balloon 140 is inserted through a core 230. This allows the first tubular body 120 of the shaft 110 and the cylindrical member 160 to move and rotate integrally with the core 230. The core 230 is made of, for example, metal. As will be described later, the first tubular body 120 of the shaft 110 and the cylindrical member 160 may not be fused to each other in advance, but the distal end of the distal tubular portion 141 of the balloon 140 may be positioned near the intended fusion site of the first tubular body 120 and the cylindrical member 160 of the shaft 110, forming a contact portion.

[0061] 4A, with the rotation axes of the core material 230 and the elastic body 210 aligned, either the core material 230 or the elastic body 210 is moved in the axial direction to place the first tubular body 120, the cylindrical member 160, and the tip-side tubular portion 141 in the hollow portion 211 of the elastic body 210. At this time, the cylindrical member 160 and the tip-side tubular portion 141 are not in contact with the inner surface of the hollow portion 211 of the elastic body 210 in the radial direction, and a gap is generated.

[0062] (Process (B)) Next, in step (B), as shown in Fig. 4B, the cylindrical member 160 and the tip-side tubular portion 141 are radially pressurized. An external force (a force toward the central axis O) is applied to the elastic body 210 by a pressurizing means (not shown). The external force applied to the elastic body 210 presses the cylindrical member 160 and the tip-side tubular portion 141 in the direction of the arrow in Fig. 4B.

[0063] As described above, by not applying pressure during the setting process in step A but applying pressure to the elastic body 210 during heating, highly accurate alignment is possible, resulting in effects such as improved fusion quality and reproducibility. In addition, because there is a clearance between the workpiece and the elastic body 210, the workpiece can be fusion-bonded without affecting it when inserted into the elastic body 210. Furthermore, by providing a desired shape to the elastic body 210, the pressure means, etc., the fusion portion of the workpiece can be tapered, two-step tapered, gently rounded, locally constricted, etc.

[0064] Next, in step B, the fused portion is irradiated with laser light L while maintaining the applied external force. Since the elastic body 210 is laser-transparent, the fused portion is directly heated. Furthermore, by locally irradiating the contact portion with laser light L, it is possible to locally heat only the fused portion and its surroundings. During heating, the core material 230 and the elastic body 210 rotate about the central axis O, thereby rotating the first tubular body 120, the balloon 140, and the cylindrical member 160 of the shaft 110 about the central axis O, thereby ensuring uniform heating. Alternatively, the objects to be bonded may not be rotated, but the irradiation unit 220 that irradiates the laser light L may be rotated about the central axis O.

[0065] The end face portion of the contact portion and its surrounding area are locally irradiated with the laser light L. Such irradiation of the laser light L causes the shaft 110, the balloon 140, and the cylindrical member 160 to generate heat themselves, and furthermore, heat is transferred from the heated members to other members (for example, when the shaft 110 generates heat, the other members are the balloon 140 and / or the cylindrical member 160), thereby fusing the contact portions between the base end side of the cylindrical member 160, the tip side of the shaft 110, and the tip-side tubular portion 141 of the balloon 140, and forming a fused portion. Preferably, at least one of the shaft 110, the balloon 140, and the cylindrical member 160, more preferably at least the shaft 110, is made to contain a laser light absorbing material, so that it is heated locally, and since the surrounding elastic body 210 is laser light transparent, the elastic body 210 is not heated, and the heat is dissipated to the elastic body and the surrounding area (e.g., the core material 230) from the moment the fused portion is heated, so that it is cooled rapidly after the laser light irradiation is stopped.

[0066] (Process (C)) In step (C), as shown in Figure 4C, the pressure applied to the elastic body 210 by the pressure applying means is released, allowing the fused balloon catheter 100 to be removed from the elastic body 210. Thereafter, the balloon catheter 100 is completed through a process such as forming a lubricious coating layer on a predetermined outer peripheral surface.

[0067] Next, we will explain the arrangement of each component during manufacturing of the balloon catheter 100 and the structure after fusion. Each of the following structures can be formed by localized laser fusion of the fused portion as shown in Figures 4A to 4C.

[0068] 5A and 5B, 6A and 6B show a two-step fusion configuration in which the cylindrical member 160 and the shaft 110 (first tubular body 120) are fused together in advance, and then the balloon 140 is fused together. Figures 7A to 7C, 8A to 8C, 9A and 9B show a configuration in which the cylindrical member 160, the shaft 110 (first tubular body 120), the balloon 140, and the cylindrical member 160 are fused together at the same time.

[0069] As will be explained below, the balloon catheter 100 can control the fusion structure near the contact points of the shaft 110, balloon 140, and cylindrical member 160 to the desired shape by controlling the position of the distal cylindrical portion 141 of the balloon 140.

[0070] Fig. 5A is a diagram showing a configuration in which the leading end 141a of the distal tubular portion 141 of the balloon 140 is positioned distally of the fusion position W between the base end of the cylindrical member 160 and the distal end of the shaft 110, i.e., a configuration in which the covering length of the distal tubular portion 141 of the balloon 140 over the cylindrical member 160 is distally closer to the fusion position W (covering length t>0). Fig. 5B is a cross-sectional view of the distal end and surrounding area of the balloon catheter 100 manufactured by laser welding the balloon 140 in the configuration shown in Fig. 5A.

[0071] As shown in FIG. 5A, when the covering length t of the distal tubular portion 141 of the balloon 140 over the cylindrical member 160 is increased beyond zero during fusion bonding, the balloon catheter 100 deepens the flow toward the proximal end of the distal tubular portion 141 of the cylindrical member 160 as shown in FIG. 5B. Specifically, a distal tubular body proximal end portion 160e1 is interposed between the distal end portion 141d of the distal tubular portion 141 and the distal end portion 122 of the first tubular body 120. The distance between the distal end portion 141d and the distal end portion 122 at the distal tubular body proximal end portion 160e1, i.e., the radial thickness of the distal tubular body proximal end portion 160e1, decreases toward the axial base end and terminates at a distal tubular body proximal end 160f1. A guidewire lumen proximal end portion 160e2 is located between the distal end portion 122 of the first tubular body 120 and the surface of the guidewire lumen 121. The radial thickness of the guidewire lumen side proximal end 160e2 decreases toward the axial proximal end and terminates at the guidewire lumen side proximal end 160f2. The distal end 141a of the distal side cylindrical portion 141 is located axially closer to the proximal end than the distal end 122a of the first tubular body 120. Furthermore, when the balloon 140 is thin, laser welding, unlike general heat welding, does not apply heat to the contact portion itself, making it less likely for the cylindrical member 160 to flow in.

[0072] Fig. 6A is a diagram showing a configuration in which the fusion position W between the base end of the cylindrical member 160 and the tip of the shaft 110 and the foremost end 141a of the tip-side tubular portion 141 of the balloon 140 are located at the same position or on the base-end side, i.e., a state in which the covering length t of the tip-side tubular portion 141 of the balloon 140 over the cylindrical member 160 is zero or a negative covering length (covering length t≦0). Fig. 6B is a cross-sectional view of the vicinity of the tip of the balloon catheter 100 manufactured by laser welding the balloon 140 in the configuration shown in Fig. 6A.

[0073] As shown in FIG. 6A, when the covering length t of the distal tubular portion 141 of the balloon 140 over the cylindrical member 160 is null or negative during fusion, a balloon catheter 100 can be manufactured having a structure in which the distal end of the shaft 110 is interposed between the cylindrical member 160 and the distal tubular portion 141 of the balloon 140, as shown in FIG. 6B. Specifically, the distal end 122 of the first tubular body 120 of the shaft 110 forms a radially inner surface 122c on the guidewire lumen 121 side, while closely covering the most distal end 141a of the distal tubular portion 141 at the axially distal end side. The distal end 122 of the first tubular body 120 of the shaft 110 forms a radially outer outer surface 122b. The outer surface 122b forms the outer surface of the balloon catheter 100. A guidewire lumen side proximal end 160e2 is located between the distal end 122 of the first tubular body 120 and the surface of the guidewire lumen 121. The radial thickness of the guidewire lumen side proximal end 160e2 decreases toward the proximal end in the axial direction and terminates at a guidewire lumen side proximal end 160f2. A distal end 141a of the distal side cylindrical portion 141 is located axially closer to the distal end than a distal end 122a of the first tubular body 120.

[0074] 7A shows a state in which the cylindrical member 160, shaft 110, and balloon 140 are simultaneously fused together, with the leading end 141a of the distal tubular portion 141 of the balloon 140 positioned near the abutment position C between the base end of the cylindrical member 160 and the distal end of the shaft 110, i.e., the state in which the overlap length t of the distal tubular portion 141 of the balloon 140 over the cylindrical member 160 is almost zero (overlap length t ≈ 0). FIGS. 7B and 7C are cross-sectional views of the distal end and surrounding area of a balloon catheter 100 manufactured by laser fusion bonding the cylindrical member 160, shaft 110, and balloon 140 in the configuration shown in FIG. 7A, with other manufacturing conditions and materials changed. In the embodiment shown in FIGS. 7 and 8, the shaft 110 is a tubular body manufactured by twin-screw extrusion or the like, in which the inner layer 124 and the outer layer 126 are pre-melted and laminated. The shaft 110 may have a reinforcing member such as a braid or a coil embedded between the inner layer 124 and the outer layer 126. Such a reinforcing member may be disposed up to the tip of the shaft 110, or may terminate just before the point where the tip-side tubular portion 141 of the balloon 140 is fused to the shaft 110.

[0075] As shown in FIG. 7A, when the balloon catheter 100 is laser-welded with the distal tubular portion 141 of the balloon 140 having almost no overlapping length with the cylindrical member 160, a balloon catheter having a structure in which the distal end of the distal tubular portion 141 is inserted between the shaft 110 and the cylindrical member 160 can be manufactured, as shown in FIGS. 7B and 7C. Specifically, in FIG. 7B, the distal end 141d of the distal tubular portion 141 of the balloon 140 extends axially toward the distal end and then radially inward. The distal end 141d of the distal tubular portion 141 is curved to cover the distal end of the outer layer 126. The distal end 141d of the distal tubular portion 141 is positioned so as to abut against the radially outer surface of the inner layer 124 of the shaft 110. The distal end 141d is located at the radially outer surface of the inner layer 124 as a distal end terminal 141f. The leading end 124a of the inner layer 124 of the shaft 110 is configured to be recessed into the cylindrical member 160 at a position closer to the axial tip than the leading end 141a of the tip-side tubular portion 141. The leading end 126a of the outer layer 126 of the shaft 110 terminates in a state sandwiched between the leading end 141d of the tip-side tubular portion 141 and the outer surface of the inner layer 124 of the shaft 110. Meanwhile, in FIG. 7C , the leading end 141d of the tip-side tubular portion 141 of the balloon 140 extends toward the axial tip and then toward the radially inward direction, but is positioned so as to block all of the outer layer 126 of the shaft 110 and part of the inner layer 124 of the shaft 110. In other words, the leading end side of the leading end 126a of the outer layer 126 is occupied by the leading end 141d of the tip-side tubular portion 141. A distal end 141f of the distal tubular portion 141 contacts the inner layer 124. A distal end 124a of the inner layer 124 is located at a position where it contacts the cylindrical member 160.

[0076] 8A shows a state in which the cylindrical member 160, the shaft 110, and the balloon 140 are simultaneously fused together, with the leading end of the distal tubular portion 141 of the balloon 140 positioned distally of the contact position C between the base end of the cylindrical member 160 and the distal end of the shaft 110, i.e., a state in which the covering length t of the distal tubular portion 141 of the balloon 140 over the cylindrical member 160 is long (covering length t>0). Figures 8B and 8C are cross-sectional views of the vicinity of the distal end of a balloon catheter 100 manufactured by laser welding the cylindrical member 160, the shaft 110, and the balloon 140 in the arrangement shown in Figure 8A, with other manufacturing conditions and materials of the members changed.

[0077] As shown in Fig. 8A, when the balloon catheter 100 is laser-welded with the distal tubular portion 141 of the balloon 140 over the cylindrical member 160 with a long covering length t, a balloon catheter having a structure in which a portion of the distal tubular portion 141 proximal to the most distal end 141a flows between the shaft 110 and the cylindrical member 160 can be manufactured, as shown in Figs. 8B and 8C. Specifically, in Fig. 8B, the distal end portion 141d of the distal tubular portion 141 of the balloon 140 includes both a portion extending axially toward the distal end and a portion extending radially inward. The most distal end 141a of the distal tubular portion 141 is located radially inward relative to the outer surface of the cylindrical member 160. Meanwhile, a distal branch portion 141d1 extends radially inward and abuts against the outer surface of the inner layer 124 of the shaft 110 (the boundary with another member on the radially outer side). The distal end 124a of the inner layer 124 of the shaft 110 is positioned so as to be recessed into the cylindrical member 160 on the axially distal side of the distal end 141a of the distal tubular portion 141. The distal end 126a of the outer layer 126 of the shaft 110 is in contact with the distal branch portion 141d1 of the distal tubular portion 141. Meanwhile, in FIG. 8C , the distal end 141d of the distal tubular portion 141 of the balloon 140 extends in both the axial direction and the radially inward direction, as in FIG. 8B , but the distal branch portion 141d1 extending radially inward has a shape that wraps around the distal end 124a of the inner layer 124. The distal branch terminal end 141g of the distal branch portion 141d1 is located on the surface of the guidewire lumen 121. The distal side of the distal end 126a of the outer layer 126 is in contact with the inner layer 124. The inner layer 124 covers the vicinity of the tip 126a of the outer layer 126 and forms the tip 124a. The inner layer 124 further extends toward the base end in the axial direction and toward the outside in the radial direction. An inner layer terminal end 124f of the inner layer 124 is located between the inner surface of the tip portion 141d of the tip-side tubular portion 141 and the outer surface of the outer layer 126.

[0078] 9A is a diagram showing a state in which, in simultaneous fusion bonding of a cylindrical member 160, a shaft 110, and a balloon 140, the leading end of the distal tubular portion 141 of the balloon 140 is located proximal to the abutment position C between the proximal end of the cylindrical member 160 and the distal end of the shaft 110, i.e., a state in which the covering length t of the distal tubular portion 141 of the balloon 140 with respect to the cylindrical member 160 is negative (covering length t<0). Fig. 9B is a cross-sectional view of the vicinity of the distal end of a balloon catheter 100 manufactured by laser fusion bonding the cylindrical member 160, the shaft 110, and the balloon 140 in the arrangement shown in Fig. 9A while changing other manufacturing conditions and materials of the members.

[0079] As shown in Fig. 9A, when the covering length t of the distal tubular portion 141 of the balloon 140 relative to the cylindrical member 160 is negative, a balloon catheter 100 can be manufactured having a structure in which the shaft 110 flows between the cylindrical member 160 and the distal tubular portion 141, as shown in Fig. 9B. Specifically, in Fig. 9B, the outer layer 126 of the first tubular body 120 of the shaft 110 covers the leading end 141a of the distal tubular portion 141 on the axially distal side. The outer layer 126 extends radially outward and axially proximal from the leading end 126a to form an outer layer outer surface 126b, which is the outer surface of the balloon catheter 100. The inner layer 124 of the first tubular body 120 of the shaft 110 extends between the inner surface of the outer layer 126 and the proximal surface of the cylindrical member 160, gradually reducing its radial thickness from the distal end 124a of the inner layer 124 to terminate at an inner layer terminal end 124f. The cylindrical member 160 has a guidewire lumen-side proximal end 160e2 located between the inner surface of the inner layer 124 and the surface of the guidewire lumen 121. The radial thickness of the guidewire lumen-side proximal end 160e2 decreases toward the proximal end in the axial direction and terminates at a guidewire lumen-side proximal end 160f2. The distal end 141a of the distal-side tubular portion 141 is located axially proximal to the distal end 124a of the inner layer 124 and the distal end 126a of the outer layer 126.

[0080] As described above, the balloon catheter 100 of the first embodiment includes a cylindrical member 160, and a balloon 140 arranged on the base end side of the cylindrical member 160, the balloon 140 including a tip-side tubular portion 141, an actuating portion 143 having a cylindrically expandable space portion 140a, and a tip-side tapered portion 142 connected between the tip-side tubular portion 141 and the actuating portion 143, and in an axial cross-sectional view, the tip end 141a of the tip-side tubular portion 141 is located radially inward relative to the outer surface 161 of the cylindrical member 160.

[0081] In the balloon catheter 100, the leading end 141a of the tip-side tubular portion 141 is located radially inward relative to the outer surface 161 of the cylindrical member 160, thereby increasing the bonding area of the tip-side tubular portion 141 to the cylindrical member 160. Furthermore, the tip end 141d of the tip-side tubular portion 141 is formed so as to fit into the thick portion of the cylindrical member 160 after fusion, so that the connection with the cylindrical member 160 is maintained firmly even if the balloon bends to follow the shape of the blood vessel. Therefore, in the balloon catheter 100, the bonding strength between the cylindrical member 160 and the balloon 140 can be improved, and peeling of the tip end 141d of the balloon 140 can be suppressed.

[0082] Next, a balloon catheter 100A according to a second embodiment will be described.

[0083] The following description focuses mainly on the differences in the configuration of the second embodiment from the balloon catheter 100 of the first embodiment. Note that the balloon catheter 100A of the second embodiment can be similar to the balloon catheter 100 of the first embodiment in terms of configuration, manufacturing method, etc., other than the following differences.

[0084] As shown in FIG. 10, the balloon catheter 100A has a clamping portion 180 that clamps a part of the base end side of the cylindrical member 160 between the distal end portion 122 of the first tubular body 120 and the distal end portion 141d of the balloon 140.

[0085] 10 , the clamping portion 180 is a portion where a part of the base end portion 160e of the cylindrical member 160 is clamped between the tip end portion 122 of the first tubular body 120 and the tip end portion 141d of the tip side cylindrical portion 141 in an axial cross-sectional view. This portion is formed by a part of the base end portion 160e of the cylindrical member 160 flowing into a gap formed between the tip end portion 122 of the first tubular body 120 and the tip end portion 141d of the tip side cylindrical portion 141. A part of the base end portion 160e of the cylindrical member 160 is fused to the tip end portion 141d of the tip side cylindrical portion 141 and the tip end portion 122 of the first tubular body 120 while in contact with them.

[0086] As described above, in the balloon catheter 100A of the second embodiment, when viewed in axial cross section, the tip portion 122 of the first tubular body 120 and the tip portion 141d of the tip-side tubular portion 141 form a clamping portion 180 that clamps a portion of the cylindrical member 160.

[0087] The balloon catheter 100A clamps a portion of the base end side of the cylindrical member 160 with the clamping portion 180, which is composed of the tip portion 122 of the first tubular body 120 and the tip portion 141d of the tip-side tubular portion 141, thereby improving the bonding strength of the cylindrical member 160 to the first tubular body 120 and the balloon 140.

[0088] The balloon catheter 100 of the first embodiment and the balloon catheter 100A of the second embodiment described above can be configured as follows.

[0089] FIG. 11 shows modified examples of the balloon catheter 100 and the balloon catheter 100A.

[0090] As shown in FIG. 11(a), the balloon catheter 100 may be formed so that the most distal end 122a of the distal end portion 122 of the first tubular body 120 is located more distal than the most distal end 141a of the distal-side tubular portion 141. Also, as shown in FIG. 11(b), the balloon catheter 100A may be formed so that the most distal end 122a of the distal end portion 122 of the first tubular body 120 is located more distal than the most distal end 141a of the distal-side tubular portion 141. The difference between the embodiments of FIG. 11(a) and FIG. 11(b) is the axial length of the clamping portion 180. The axial length of the clamping portion 180 in FIG. 11(a) is shorter than the axial length of the clamping portion 180 in the embodiment of FIG. 11(b). Specifically, the length in the axial direction from the forefront 141a of the tip side tubular portion 141 to the tip side tubular body side base end 160f1 is shorter than the length from the forefront 122a of the tip end 122 of the first tubular body 120 to the forefront 141a of the tip side tubular portion 141. On the other hand, in the embodiment of sub-view (b) of Figure 11, the length in the axial direction from the forefront 141a of the tip side tubular portion 141 to the tip side tubular body side base end 160f1 is longer than the length from the forefront 122a of the tip end 122 of the first tubular body 120 to the forefront 141a of the tip side tubular portion 141.

[0091] In this way, when the balloon catheter 100 and the balloon catheter 100A are formed so that the most distal end 122a of the distal end portion 122 of the first tubular body 120 is located more distal than the most distal end 141a of the distal-side cylindrical portion 141, the contact area of the cylindrical member 160 with the first tubular body 120 increases, and the distal end portion 122 of the first tubular body 120 slides into the base end portion 160e of the cylindrical member 160, providing an anchoring effect. Therefore, in the balloon catheter 100 and the balloon catheter 100A, the bonding strength of the cylindrical member 160 to the first tubular body 120 and the balloon 140 is more effectively improved, and peeling of the distal end portion 141d of the balloon 140 can be suppressed.

[0092] In the balloon catheters of the above embodiment, the above modification, and the partial cross-sectional views shown in FIGS. 5 to 9, common components have the same configuration and provide the same effects even if no particular reference numerals or explanations are given. [Explanation of symbols]

[0093] 100, 100A balloon catheter, 110 shaft, 120 first tubular body (inner tube), 121 guidewire lumen, 130 second tubular body (outer tube), 131 pressurized medium lumen; 140 balloon (140a space portion), 141 Tip side cylindrical part (141a tip, 141b radially outer outer surface, 141c radially inner inner surface, 141d tip), 142 Tip side tapered portion, 143 operating parts, 144 proximal tapered portion, 145 Proximal tubular part, 150 hub, 160 cylindrical members, 161 outer surface; 162 Boundary, 170 contrast marker section, 180 clamping part, 200 Balloon catheter manufacturing equipment, 210 Elastic body, 220 irradiation unit, 240 core material, G guidewire, L Laser light.

Claims

1. A cylindrical member; a balloon disposed on the base end side of the cylindrical member, the balloon including a distal tubular portion, an operating portion having a cylindrically expandable space, and a distal tapered portion connected between the distal tubular portion and the operating portion; a balloon catheter in which, in an axial cross-sectional view, a leading end of the tip-side tubular portion is located radially inward relative to an outer surface of the cylindrical member, and at least the leading end of the tip-side tubular portion and a portion of the radially inner inner surface radially inward of the leading end are located in contact with the cylindrical member.

2. 2. The balloon catheter according to claim 1, wherein, in an axial cross-sectional view, the cylindrical member includes a boundary portion that covers and continuously contacts the tip portion, the boundary portion having the tip end of the tip-side tubular portion, a radially outer outer surface radially outward from the tip end, and the radially inner inner surface.

3. The balloon catheter according to claim 2 , wherein the boundary portion includes a curved portion that continues in a curved shape through the most distal end of the distal tubular portion.

4. In an axial cross-sectional view, the cylindrical member includes a curved boundary portion that covers and continuously contacts the front end of the front end side cylindrical portion and a front end portion of an outer surface radially outward from the front end, 2. The balloon catheter according to claim 1, wherein the distance between the boundary portion and the outer surface in the radial direction decreases according to the curved shape of the boundary portion and terminates at the proximal end of the outer surface of the cylindrical member.

5. a first tubular body disposed on a proximal end side of the cylindrical member; The balloon catheter according to any one of claims 1 to 4, wherein the space is formed by an outer surface of the first tubular body and an inner surface of the working portion.

6. 6. The balloon catheter according to claim 5, wherein, in an axial cross-sectional view, the distal end portion of the first tubular body and the distal end portion of the distal-side cylindrical portion form a clamping portion that clamps a portion of the cylindrical member.

7. The balloon catheter according to claim 5 , wherein a distal end of the first tubular body is located distally of the distal end of the distal cylindrical portion.

8. The balloon catheter according to claim 5 , wherein the distal end of the distal tubular portion is located distally of the distal end of the first tubular body.

9. A cylindrical member; a balloon disposed on the base end side of the cylindrical member, the balloon including a distal cylindrical portion and an actuation portion having an expandable space portion; a balloon catheter in which, in an axial cross-sectional view, the tip end of the tip-side tubular portion is formed in a tongue shape with a convex axial tip end, and the cylindrical member tightly covers the tongue-shaped tip end on the radial inside and outside.

10. a first tubular body disposed on a proximal end side of the cylindrical member; The balloon catheter according to claim 9 , wherein the space is formed by an outer surface of the first tubular body and an inner surface of the working portion.

11. 11. The balloon catheter according to claim 10, wherein, in an axial cross-sectional view, the distal end portion of the first tubular body and the distal end portion of the distal-side cylindrical portion form a clamping portion that clamps a portion of the cylindrical member.

Images