Balloon for balloon catheter

Abstract

To provide a balloon for a balloon catheter smoothly insertable through a body cavity, with track ability and push ability improved while capable of enhancing strength of the balloon so as to prevent the balloon from extending in an unintended direction, as well as, from breaking.SOLUTION: There is provided a balloon for a balloon catheter comprising protrusion parts 60 which protrude outward in a radial direction relative to an outer surface of a balloon main body 20k, and extend in a longitudinal axis direction of the balloon main body 20. In a cross section in the radial direction, the protrusion part 60 provided on a straight pipe part comprises: a base end 61 connected to an external face of the balloon main body 20; and a tip end 62 which is provided outside in the radial direction relative to the base end 61, and being an outer end in the radial direction of the protrusion part 60. The protrusion part 60 provided on a proximal side sleeve and / or a distal side sleeve, tilts toward a first direction d1 or a second direction d2 in a circumferential direction of the balloon main body 20, and an angle θ formed of a straight line Lp connecting a middle point of the base end 61 in a width direction and the tip end 62, and a perpendicular line Lv of the base end 61, is equal to or greater than 45°.SELECTED DRAWING: Figure 6

Description

Technical Field

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

Background Art

[0002] When a stenosis hardened by calcification or the like is formed on the inner wall of a blood vessel, diseases such as angina pectoris and myocardial infarction are caused. As one of these treatments, there is an angioplasty in which a stenosis is expanded using a balloon catheter. Angioplasty is a minimally invasive treatment that does not require a thoracotomy such as bypass surgery and is widely performed.

[0003] A balloon catheter is inserted into a body cavity in a contracted state of the balloon and delivered through the body cavity to a treatment site. At the time of delivery, the conveyance of the balloon is controlled by transmitting an operation from the proximal side to the distal side where the balloon is disposed. At this time, it is required that the insertion through the body cavity is easy and that the transmission of the operation from the proximal side to the distal side is easy (high pushability). In addition, when a fluid is introduced into the lumen of the balloon to expand the balloon, there are problems that the balloon extends in an undesired direction due to the pressure of the fluid or the balloon is damaged. In response to such problems, for example, Patent Document 1 discloses a balloon catheter in which the fixing strength between the balloon and the outer shaft is improved without increasing the outer diameter at the fixing portion between the balloon and the outer shaft.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Balloon catheters are required not only to have high pushability and balloon strength, but also the ability to smoothly insert into the body cavity and the ability to flexibly advance following the tortuous body cavity (trackability). However, conventional balloon catheters have been insufficient to achieve both improved strength and smooth insertion and improved trackability. Therefore, an object of the present invention is to provide a balloon for a balloon catheter that has increased balloon strength to prevent elongation and breakage of the balloon in undesired directions, and that can smoothly insert into the body cavity and has improved trackability and pushability.

Means for Solving the Problems

[0006] One embodiment of the balloon for a balloon catheter of the present invention that can solve the above problems is a balloon for a balloon catheter having a straight tube portion, a proximal tapered portion located proximal to the straight tube portion, a proximal sleeve portion located proximal to the proximal tapered portion, a distal tapered portion located distal to the straight tube portion, and a distal sleeve portion located distal to the distal tapered portion, the balloon for a balloon catheter having a balloon body having an outer surface and an inner surface, and a protruding portion protruding radially outward from the outer surface of the balloon body and extending in the longitudinal axis direction of the balloon body, and in the radial cross section, the protruding portion provided in the straight tube portion has a proximal end connected to the outer surface of the balloon body, and a distal end located radially outward of the proximal end and being the radially outer end of the protruding portion, and satisfies at least one of the following (1) and (2). (1) In the radial cross section, the protruding portion provided in the proximal sleeve portion is inclined in a first direction or a second direction in the circumferential direction of the balloon body, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 45° or more. (2) In the cross-section in the radial direction, the protruding portion provided on the distal sleeve portion is inclined in the first direction or the second direction in the circumferential direction of the balloon body, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the tip end and the perpendicular line to the proximal end is 45° or more. With such a configuration, by having the protruding portion, the strength of the balloon is increased to prevent the balloon from extending or breaking in an undesired direction, and when the balloon is advanced or retracted, the protruding portion provided on the distal sleeve portion and / or the proximal sleeve portion that becomes the leading end is inclined in the first direction or the second direction in the circumferential direction of the balloon body. As a result, the inclined protruding portion acts like a cushion, allowing the balloon catheter to smoothly pass through the body cavity and improving the trackability. Further, since the protruding portion provided on the distal sleeve portion and / or the proximal sleeve portion is inclined in the first direction or the second direction in the circumferential direction of the balloon body, the outer diameter of the balloon can be suppressed without reducing the protruding portion itself, achieving both the strength of the balloon and the ease of insertion into the body cavity.

[0007] It is preferable to satisfy at least one of the following (3) and (4). (3) In the cross-section in the radial direction, the protruding portion of the proximal sleeve portion is inclined in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the tip end and the perpendicular line to the proximal end is 45° or more. The proximal sleeve portion has an inner protruding portion that protrudes inward in the radial direction from the inner surface of the balloon body and extends in the longitudinal axis direction. (4) In the cross-section in the radial direction, the protruding portion of the distal sleeve portion is inclined in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the tip end and the perpendicular line to the proximal end is 45° or more. The distal sleeve portion has an inner protruding portion that protrudes inward in the radial direction from the inner surface of the balloon body and extends in the longitudinal axis direction.

[0008] It is preferable to satisfy at least one of the following (5) and (6). (5) In the radial cross-section, the protrusion of the proximal sleeve portion leans in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 45° or more. In the radial cross-section, the protrusion of the proximal tapered portion leans in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 30° or more. (6) In the radial cross-section, the protrusion of the distal sleeve portion leans in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 45° or more. In the radial cross-section, the protrusion of the distal tapered portion leans in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 30° or more.

[0009] It is preferable to satisfy at least one of the following (7) and (8). (7) In the radial cross-section, the protrusion of the proximal sleeve portion leans in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 45° or more. In the radial cross-section, the protrusion of the proximal tapered portion leans in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 30° or more. The proximal sleeve portion and the proximal tapered portion have an inner protrusion that protrudes radially inward from the inner surface of the balloon body and extends in the longitudinal axis direction. (8) In the radial cross-section, the protrusion of the distal sleeve portion leans in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 45° or more. In the radial cross-section, the protruding portion of the distal tapered portion is tilted in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the tip end and the perpendicular line of the proximal end is 30° or more. The distal sleeve portion and the distal tapered portion have an inner protruding portion that protrudes inward in the radial direction from the inner surface of the balloon body and extends in the longitudinal axis direction.

Advantages of the Invention

[0010] According to the balloon for the balloon catheter described above, by having the protruding portion, the strength of the balloon is increased to prevent the balloon from extending or breaking in an undesired direction, and when the balloon is advanced or retracted, the distal sleeve portion and / or the proximal sleeve portion provided at the leading end, the protruding portion provided thereon is tilted in the first direction or the second direction in the circumferential direction of the balloon body. Thus, the tilted protruding portion acts like a cushion, enabling smooth insertion through the body cavity and improving the trackability of the balloon catheter. Also, since the protruding portion provided on the distal sleeve portion and / or the proximal sleeve portion is tilted in the first direction or the second direction in the circumferential direction of the balloon body, the outer diameter of the balloon can be suppressed without reducing the protruding portion itself. Therefore, both the strength of the balloon and the ease of insertion into the body cavity can be achieved.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0012] Hereinafter, the present invention will be specifically described based on embodiments. However, the present invention is not limited by the following embodiments, and it is of course possible to appropriately modify and implement it within a range that conforms to the gist of the foregoing and following descriptions, and all of them are included in the technical scope of the present invention. In each drawing, for the sake of convenience, hatching, reference numerals of members, etc. may be omitted, but in such cases, reference shall be made to the specification and other drawings. In addition, the dimensions of various members in the drawings may differ from the actual dimensions because priority is given to facilitating the understanding of the features of the present invention.

[0013] The balloon for a balloon catheter according to an embodiment of the present invention is a balloon for a balloon catheter having a straight tube portion, a proximal tapered portion located closer to the proximal side than the straight tube portion, a proximal sleeve portion located closer to the proximal side than the proximal tapered portion, a distal tapered portion located farther from the proximal side than the straight tube portion, and a distal sleeve portion located farther from the proximal side than the distal tapered portion, and having a balloon body having an outer surface and an inner surface, and a protruding portion protruding radially outward from the outer surface of the balloon body and extending in the longitudinal axis direction of the balloon body. In the radial cross-section, the protruding portion provided in the straight tube portion has a proximal end connected to the outer surface of the balloon body and a distal end located radially outward of the proximal end and being the radially outer end of the protruding portion, and satisfies at least one of the following (1) and (2). (1) In the radial cross-section, the protruding portion provided on the proximal sleeve portion is inclined in the first direction or the second direction in the circumferential direction of the balloon body, and the angle formed by the straight line connecting the midpoint in the width direction of the base end and the tip end and the perpendicular line of the base end is 45° or more. (2) In the radial cross-section, the protruding portion provided on the distal sleeve portion is inclined in the first direction or the second direction in the circumferential direction of the balloon body, and the angle formed by the straight line connecting the midpoint in the width direction of the base end and the tip end and the perpendicular line of the base end is 45° or more.

[0014] Thus, the balloon for a balloon catheter according to an embodiment of the present invention has a protruding portion, thereby enhancing the strength of the balloon to prevent the balloon from extending or breaking in an undesired direction. When the balloon is moved forward or backward, the protruding portion provided on the distal sleeve portion and / or the proximal sleeve portion at the leading end is inclined in the first direction or the second direction in the circumferential direction of the balloon body. Due to the inclined protruding portion acting like a cushion, it is possible to smoothly insert through the body cavity and obtain a balloon catheter with improved trackability. Further, since the protruding portion provided on the distal sleeve portion and / or the proximal sleeve portion is inclined in the first direction or the second direction in the circumferential direction of the balloon body, the outer diameter of the balloon can be suppressed without reducing the protruding portion itself. Therefore, both the strength of the balloon and the ease of insertion into the body cavity can be achieved.

[0015] With reference to FIGS. 1 to 10, the balloon for a balloon catheter according to an embodiment of the present invention will be described. FIG. 1 shows a side view of a balloon catheter according to an embodiment of the present invention. FIG. 2 shows a cross-sectional view taken along line II-II of FIG. 1, and represents a cross-sectional view of the straight tube portion of the balloon of the balloon catheter shown in FIG. 1 in an expanded state. FIG. 3 shows a cross-sectional view of the expanded portion shown in FIG. 2 in a contracted state. FIG. 4 shows a cross-sectional view taken along line IV-IV of FIG. 1, and represents a cross-sectional view of the distal tapered portion of the balloon of the balloon catheter shown in FIG. 1 in an expanded state. FIG. 5 shows a cross-sectional view of the distal tapered portion shown in FIG. 4 in a contracted state. FIG. 6 shows a cross-sectional view taken along line VI-VI of FIG. 1, and represents a cross-sectional view of the distal sleeve portion of the balloon of the balloon catheter shown in FIG. 1. FIG. 7 shows a modified example of FIG. 6. FIGS. 8 to 10 show cross-sectional views of balloons for balloon catheters according to different embodiments of the present invention. FIG. 8 shows a cross-sectional view of the distal sleeve portion, and FIGS. 9 and 10 show cross-sectional views of the distal tapered portion in a contracted state. FIG. 9 shows a cross-sectional view of the more distal distal tapered portion, and FIG. 10 shows a cross-sectional view of the more proximal distal tapered portion. In this specification, the balloon for a balloon catheter may be simply referred to as a "balloon".

[0016] In the present invention, the proximal side refers to the direction on the user's hand side with respect to the extending direction of the balloon catheter 1 or the longitudinal axis direction of the shaft 3, and the distal side refers to the direction opposite to the proximal side, that is, the direction on the side of the subject to be treated. The longitudinal axis direction of the balloon catheter 1 is preferably the same as the longitudinal axis direction x of the balloon body 20. Also, in this specification, even for members other than the elongated members, it will be described as having the same longitudinal axis direction x. The radial direction y of the balloon body 20 is a direction perpendicular to the longitudinal axis direction x and is a direction connecting the center of the balloon body 20 and a point on the outer edge of the balloon body 20 in an expanded state in a cross-section perpendicular to the longitudinal axis direction x. The circumferential direction z of the balloon body 20 is a direction along the outer edge of the balloon body 20 in an expanded state in a cross-section in the radial direction y.

[0017] As shown in FIG. 1, the balloon catheter 1 has a shaft 3 and a balloon 2 provided at the distal end of the shaft 3. The balloon catheter 1 is configured such that fluid is supplied into the balloon 2 through the shaft 3, and the inflation and deflation of the balloon 2 can be controlled using an inflator (balloon pressurizer). The fluid may be pressurized fluid pressurized by a pump or the like.

[0018] The shaft 3 preferably has a fluid flow path therein and further has an insertion passage for a guide wire. In order for the shaft 3 to have a fluid flow path and a guide wire insertion passage therein, for example, the shaft 3 has an outer tube 31 and an inner tube 32, the inner tube 32 functions as an insertion passage for the guide wire, and the space between the inner tube 32 and the outer tube 31 functions as a fluid flow path. In the case where the shaft 3 has such a configuration of having the outer tube 31 and the inner tube 32, it is preferable that the inner tube 32 extends from the distal end of the outer tube 31 and penetrates to the distal side of the balloon 2, the distal side of the balloon 2 is joined to the inner tube 32, and the proximal side of the balloon 2 is joined to the outer tube 31.

[0019] As shown in FIG. 1, the balloon 2 for a balloon catheter has a straight tube portion 23, a proximal tapered portion 22 located proximal to the straight tube portion 23, a proximal sleeve portion 21 located proximal to the proximal tapered portion 22, a distal tapered portion 24 located distal to the straight tube portion 23, and a distal sleeve portion 25 located distal to the distal tapered portion 24, and has a balloon body 20 having an outer surface and an inner surface, and a protruding portion 60 protruding outward in the radial direction y from the outer surface of the balloon body 20 and extending in the longitudinal axis direction x of the balloon body 20. In the cross-section in the radial direction y, the protruding portion 60 provided in the straight tube portion 23 has a proximal end 61 connected to the outer surface of the balloon body 20 and a distal end 62 located outward in the radial direction y from the proximal end 61 and being the outer end in the radial direction y of the protruding portion 60, and satisfies at least one of the following (1) and (2). (1) In the cross-section in the radial direction y, the protruding portion 60 provided on the proximal sleeve portion 21 is inclined in the first direction d1 or the second direction d2 in the circumferential direction z of the balloon body 20, and a straight line L connecting the midpoint in the width direction of the proximal end 61 and the distal end 62 p and the perpendicular line L of the proximal end 61 v The angle θ formed therewith is 45° or more. (2) In the cross-section in the radial direction y, the protruding portion 60 provided on the distal sleeve portion 25 is inclined in the first direction d1 or the second direction d2 in the circumferential direction z of the balloon body 20, and a straight line L connecting the midpoint in the width direction of the proximal end 61 and the distal end 62 p and the perpendicular line L of the proximal end 61 v The angle θ formed therewith is 45° or more. Since the balloon 2 has the protruding portion 60, the strength of the balloon 2 can be increased to prevent the balloon 2 from stretching or breaking in an undesired direction. Further, when the balloon 2 is inserted into the body cavity and delivered to the lesion in the body cavity, the protruding portion 60 provided on the distal sleeve portion 25 and / or the proximal sleeve portion 21 that becomes the leading end in the forward or backward movement of the balloon 2 is inclined in the first direction d1 or the second direction d2 in the circumferential direction z of the balloon body 20. As a result, the inclined protruding portion 60 acts like a cushion, so that the balloon catheter balloon 2 can be smoothly inserted through the body cavity and the trackability can be improved. Furthermore, since the protruding portion 60 provided on the distal sleeve portion 25 and / or the proximal sleeve portion 21 is inclined in the first direction d1 or the second direction d2 in the circumferential direction z of the balloon body 20, the outer diameter of the balloon 2 can be suppressed without reducing the protruding portion 60 itself. Therefore, both the strength of the balloon 2 and the ease of insertion into the body cavity can be achieved.

[0020] As shown in FIG. 1, the balloon 2 has a straight tube portion 23, a proximal tapered portion 22 located proximal to the straight tube portion 23, a proximal sleeve portion 21 located proximal to the proximal tapered portion 22, a distal tapered portion 24 located distal to the straight tube portion 23, and a distal sleeve portion 25 located distal to the distal tapered portion 24. At least a part of the proximal sleeve portion 21 and the distal sleeve portion 25 can be configured to be fixed to the shaft 3. In the case where the shaft 3 has an outer tube 31 and an inner tube 32, at least a part of the proximal sleeve portion 21 can be fixed to the outer tube 31, and at least a part of the distal sleeve portion 25 can be fixed to the inner tube 32.

[0021] The proximal tapered portion 22, the straight tube portion 23, and the distal tapered portion 24 are parts that are expanded when fluid is supplied into the balloon 2 through the shaft 3. It is preferable that the proximal sleeve portion 21 and the distal sleeve portion 25 do not expand even when fluid is supplied into the balloon 2. Thereby, the fixation between the balloon 2 and the shaft 3 can be stabilized even in the expanded state of the balloon 2.

[0022] The straight tube portion 23 preferably has the same diameter in the longitudinal axis direction x, and the proximal tapered portion 22 and the distal tapered portion 24 are preferably formed to have a reduced diameter as they move away from the straight tube portion 23. Since the proximal tapered portion 22 and the distal tapered portion 24 have a reduced diameter, when the balloon 2 is contracted, the outer diameters of the proximal end portion and the distal end portion of the balloon 2 can be reduced, and the step between the shaft 3 and the balloon 2 can be reduced, making it easier to insert the balloon 2 into the body cavity.

[0023] As shown in FIG. 2, the balloon 2 has a balloon body 20 having an outer surface and an inner surface, and a protruding portion 60 that protrudes outward in the radial direction y from the outer surface of the balloon body 20 and extends in the longitudinal axis direction x of the balloon body 20. When the balloon 2 is delivered to the diseased part, the balloon body 20 can be expanded as shown in FIG. 2, and treatments such as incising the stenotic part of the diseased part can be performed by the protruding portion 60.

[0024] The protruding portion 60 provided in the straight tube portion 23 has a proximal end 61 connected to the outer surface of the balloon body 20 and a distal end 62 located outward in the radial direction y from the proximal end 61, which is the outer end in the radial direction y of the protruding portion 60. Regardless of the shape of the cross-section of the protruding portion 60 in the radial direction y, the outer end in the radial direction y can be uniquely determined, and the distal end 62 of the protruding portion 60 can be defined. It is preferable to fix the balloon 2 to the diseased part or make a cut in the diseased part at the distal end 62, and further cause the protruding portion 60 to penetrate into the diseased part up to the proximal end 61 side to incise the diseased part and expand the stenotic part. The distal end 62 of the protruding portion 60 may have a sharp shape with an acute angle, or may have a shape with a curved surface or a flat surface, but from the above viewpoints, the distal end 62 preferably has a sharp shape.

[0025] The proximal end 61 has a predetermined width in the circumferential direction z of the balloon body 20. The width of the proximal end 61 in the circumferential direction z is preferably 1 / 100 or more of the circumferential length of the balloon body 20, more preferably 1 / 80 or more, even more preferably 1 / 70 or more, and preferably 1 / 4 or less, more preferably 1 / 8 or less, even more preferably 1 / 10 or less.

[0026] As shown in FIG. 2, a plurality of protruding portions 60 may be provided in the circumferential direction z, or although not shown, one protruding portion 60 may be provided in the circumferential direction z. When a plurality of protruding portions 60 are provided in the circumferential direction z, the number of the protruding portions 60 in the circumferential direction z is not particularly limited, but for example, 2 or more is preferable, 3 or more is more preferable, and 4 or more may be sufficient. Also, 10 or less is preferable, 8 or less is preferable, and 6 or less may be sufficient. In this case, the protruding portions 60 are preferably arranged at intervals in the circumferential direction z, and more preferably arranged at equal intervals in the circumferential direction z. Thereby, it becomes easier to fix the balloon 2 and incise the stenosis part.

[0027] The protruding portion 60 may be continuously provided from the proximal end to the distal end of the balloon body 20, or may be intermittently provided. Also, the protruding portion 60 may be arranged parallel to the longitudinal axis direction x of the balloon body 20, or may be arranged in a spiral shape so as to go around the outer surface of the balloon body 20 in the circumferential direction z. If the protruding portion 60 is arranged parallel to the longitudinal axis direction x, the stenosis part can be incised straight by the protruding portion 60. If the protruding portion 60 is arranged in a spiral shape, the stenosis part can be incised obliquely by the protruding portion 60.

[0028] The shape of the cross section perpendicular to the longitudinal axis direction x of the protruding portion 60 may be any shape, may be a substantially triangular shape as shown in FIG. 2, or may be a polygon, a fan shape, a wedge shape, a convex shape, a spindle shape, etc.

[0029] The protruding portion 60 provided on the straight tube portion 23 is preferably not tilted in either the first direction d1 or the second direction d2 in the circumferential direction z. Thereby, the fixing of the balloon 2 to the lesion part by the protruding portion 60 and the incision of the stenosis part can be efficiently performed. When the protruding portion 60 is not tilted in either the first direction d1 or the second direction d22 in the circumferential direction z, a straight line L connecting the midpoint in the width direction of the proximal end 61 and the distal end 62 p and the perpendicular line L of the proximal end 61 v coincide, that is, a straight line L connecting the midpoint in the width direction of the proximal end 61 and the distal end 62 p and the perpendicular line L of the proximal end 61 vThe angle formed is preferably 0°. An absolute value of the angle of 3° or less, 5° or less, or 10° or less is also acceptable. At this time, the above-mentioned straight line L p and the perpendicular line L v to the proximal end 61 form an angle that is measured starting from the midpoint in the width direction of the proximal end 61 and is the angle formed by the straight line L p with respect to the perpendicular line L v to the proximal end 61 in the direction in which the protruding portion 60 falls. Here, the perpendicular line L v is a perpendicular line to the line segment connecting one end and the other end in the circumferential direction z of the proximal end 61 in the cross-section in the radial direction y.

[0030] The maximum value of the height of the protruding portion 60 in the straight tube portion 23 is preferably 1 times or more, more preferably 1.5 times or more, and even more preferably 2 times or more of the film thickness of the balloon body 20, and 50 times or less, 30 times or less, or 10 times or less is also acceptable. When the height of the protruding portion 60 is within the above range, it becomes easy to incise the stenosis portion by the protruding portion 60, the elongation of the balloon 2 in the longitudinal axis direction x can be easily prevented, and the pushability of the balloon 2 can also be improved. The height of the protruding portion 60 can be obtained by subtracting the length from the center of the balloon body 20 to the point where the line segment intersects the outer edge of the balloon body 20 from the length of the line segment connecting the center of the balloon body 20 and the tip 62 in the cross-section in the radial direction y.

[0031] As shown in FIG. 3, in the contracted state of the balloon 2, it is preferable that the balloon body 20 in the straight tube portion 23 forms blades 29 and the blades 29 are folded. At this time, the protruding portion 60 is formed in a portion other than the blades 29, and it is preferable that the blades 29 are folded so as to cover the protruding portion 60. The balloon 2 is transported to the lesion part in the body cavity in the contracted state, but since the protruding portion 60 is covered by the blades 29, it is possible to prevent the protruding portion 60 from unnecessarily damaging the body cavity wall or the protruding portion 60 from being damaged during transportation. Even in the contracted state, it is preferable that the protruding portion 60 provided in the straight tube portion 23 does not fall in either the first direction d1 or the second direction d2 in the circumferential direction z. Thereby, it is possible to maintain a state in which the protruding portion 60 does not fall when the balloon 2 is expanded.

[0032] The number of blades 29 in the contracted state of the balloon 2 is not particularly limited, but for example, two or more are preferable, three or more are more preferable, four or more may be used, and ten or less are preferable, eight or less are more preferable, and six or less are even more preferable. If the number of blades 29 is within the above range, the balloon 2 can be easily contracted.

[0033] As shown in FIG. 4, the protruding portion 60 provided on the distal tapered portion 24 may not fall in either the first direction d1 or the second direction d2 in the circumferential direction z. Although not shown for the proximal tapered portion 22, similar to the distal tapered portion 24, the protruding portion 60 provided on the proximal tapered portion 22 may not fall in either the first direction d1 or the second direction d2 in the circumferential direction z. Since the protruding portion 60 of the tapered portion does not fall in the expanded state of the balloon 2, the balloon 2 can be fixed to the lesion or the stenosis can be incised by the protruding portion 60 disposed on the tapered portion. In the contracted state of the balloon 2 as shown in FIG. 5, since the tapered portion is easily folded so that the outer diameter is smaller than that of the straight tube portion 23, the balloon 2 can be delivered to the lesion without significantly impairing the insertability of the balloon 2 even if the protruding portion 60 does not fall.

[0034] The balloon 2 satisfies at least one of the following (1) and (2). (1) In the cross section in the radial direction y, the protruding portion 60 provided on the proximal sleeve portion 21 falls in the first direction d1 or the second direction d2 in the circumferential direction z of the balloon body 20, and a straight line L connecting the midpoint in the width direction of the proximal end 61 and the distal end 62 p and the perpendicular line L of the proximal end 61 v form an angle θ of 45° or more. (2) In the cross section in the radial direction y, the protruding portion 60 provided on the distal sleeve portion 25 falls in the first direction d1 or the second direction d2 in the circumferential direction z of the balloon body 20, and a straight line L connecting the midpoint in the width direction of the proximal end 61 and the distal end 62 p and the perpendicular line L of the proximal end 61 v form an angle θ of 45° or more.

[0035] Here, the perpendicular line L v is a perpendicular line to the line segment connecting one end and the other end in the circumferential direction z of the proximal end 61 in the cross-section in the radial direction y.

[0036] FIG. 6 shows a cross-sectional view of the distal sleeve portion 25. Since the proximal sleeve portion 21 can be similarly described, it will be described with reference to FIG. 6. As shown in FIG. 6, the protruding portion 60 provided in the proximal sleeve portion 21 and / or the distal sleeve portion 25 is inclined in the first direction d1 or the second direction d2 in the circumferential direction z, and the straight line L connecting the midpoint in the width direction of the proximal end 61 and the distal end 62 p and the perpendicular line L of the proximal end 61 v form an angle θ of 45° or more. With such a configuration, when the balloon 2 is conveyed in the body cavity to the lesion portion, the inclined protruding portion 60 acts like a cushion between the balloon body 20 and the body cavity wall, so that the balloon 2 can be smoothly inserted through the body cavity and the balloon 2 with improved trackability can be obtained. Further, since the protruding portion 60 is only inclined in the circumferential direction z and the protruding portion 60 itself is not reduced, the effect of preventing the balloon 2 from stretching and improving the pushability by the protruding portion 60 can be maintained while suppressing the outer diameter of the balloon 2 to facilitate the insertion of the balloon 2. The angle θ is preferably 50° or more, more preferably 60° or more, and even more preferably 65° or more. The upper limit of the angle θ is naturally limited because the proximal end 61 is connected to the outer surface of the balloon body 20 and the distal end 62 can only be inclined until it contacts the outer surface of the balloon body 20. For example, the angle θ may be 100° or less, 95° or less, or 90° or less. At this time, the straight line L p and the perpendicular line L of the proximal end 61 v form an angle θ that is an angle formed by the straight line L p with respect to the perpendicular line L of the proximal end 61 in the direction in which the protruding portion 60 is inclined starting from the midpoint in the width direction of the proximal end 61. v is an angle formed by the straight line L

[0037] Here, when the protrusion 60 falls in the first direction d1 or the second direction d2 in the circumferential direction z, the outer end in the radial direction y of the protrusion 60 in that state is different from the outer end when the protrusion 60 does not fall. However, in this specification, the tip 62 when the protrusion 60 falls is assumed to refer to the same portion as the tip 62 when the protrusion 60 does not fall.

[0038] In both the proximal sleeve portion 21 and the distal sleeve portion 25, it is preferable that the protrusion 60 falls in the first direction d1 or the second direction d2 in the circumferential direction z. Thereby, when the balloon 2 is advanced and retracted in the body cavity, the protrusions 60 provided on both the distal sleeve portion 25 and the proximal sleeve portion 21, which are at the front, act like a cushion, and the balloon 2 can smoothly pass through the body cavity in both the forward and backward directions, and the balloon 2 with improved trackability can be obtained.

[0039] Alternatively, only in the distal sleeve portion 25, the protrusion 60 may fall in the first direction d1 or the second direction d2 in the circumferential direction z, and in the proximal sleeve portion 21, the protrusion 60 may not fall. Thereby, the protrusion 60 provided on the distal sleeve portion 25, which is at the front when the balloon 2 is advanced in the body cavity, acts like a cushion, and the balloon 2 can be easily advanced. At this time, since the protrusion 60 arranged in the proximal sleeve portion 21 can support the proximal portion of the balloon 2 against the body cavity wall during transportation, the trackability of the balloon 2 can be improved.

[0040] Or alternatively, only in the proximal sleeve portion 21, the protrusion 60 may fall in the first direction d1 or the second direction d2 in the circumferential direction z, and in the distal sleeve portion 25, the protrusion 60 may not fall. Thereby, it becomes possible to perform a treatment in which the balloon 2 gently advances while scraping the body cavity wall by the protrusion 60 arranged in the distal sleeve portion 25, which is the front side of the balloon 2, and when the balloon 2 is retracted, it can be easily retracted by the cushioning action of the protrusion 60 arranged and fallen in the proximal sleeve portion 21.

[0041] As shown in FIG. 7, when a plurality of protrusions 60 are provided in the circumferential direction z, one protrusion 60 may fall in the first direction d1 in the circumferential direction z, and the other protrusions 60 may fall in the second direction d2 in the circumferential direction z.

[0042] As shown in FIG. 6, it is preferable that a space is formed between the tip 62 of the fallen protrusion 60 and the outer surface of the balloon body 20, and the distance h from the outer surface of the balloon body 20 to the tip 62, which can be an index representing the size of this space, is preferably a predetermined value or more. The distance h can be defined as the distance between the tangent line of the outer surface of the balloon body 20 perpendicular to the line segment connecting the center of the balloon body 20 and the tip 62 and a straight line parallel to the tangent line and passing through the tip 62. The distance h is preferably 1 / 5 or more of the film thickness of the balloon body 20, more preferably 1 / 4 or more, still more preferably 1 / 2 or more, and is also allowed to be 10 times or less, 5 times or less, or 3 times or less. If the distance h is within the above range, the size of the space formed between the tip 62 of the fallen protrusion 60 and the outer surface of the balloon body 20 can be made a predetermined value or more, and the tracking performance of the balloon 2 can be improved by the cushioning action of the fallen protrusion 60.

[0043] In any case, the protrusions 60 arranged in the sleeve portion may fall in all ranges in the longitudinal axis direction x or may fall in a part of the longitudinal axis direction x. The range in which the protrusions 60 are fallen can be determined according to how much cushioning property is to be imparted.

[0044] The balloon 2 preferably satisfies at least one of the following (3) and (4). (3) In the cross-section in the radial direction y, the protrusions 60 of the proximal sleeve portion 21 fall in the first direction d1 or the second direction d2, and the straight line L p connecting the midpoint in the width direction of the base end 61 and the tip 62 v and the perpendicular line L The proximal sleeve portion 21 has an inner protruding portion 70 that protrudes inward in the radial direction y from the inner surface of the balloon body 20 and extends in the longitudinal axis direction x. (4) In the cross-section in the radial direction y, the protruding portion 60 of the distal sleeve portion 25 is inclined in the first direction d1 or the second direction d2, and a straight line L connecting the midpoint in the width direction of the proximal end 61 and the distal end 62 p and the perpendicular line L of the proximal end 61 v form an angle of 45° or more, The distal sleeve portion 25 has an inner protruding portion 70 that protrudes inward in the radial direction y from the inner surface of the balloon body 20 and extends in the longitudinal axis direction x.

[0045] As shown in FIG. 8, it is preferable that the proximal sleeve portion 21 and / or the distal sleeve portion 25 have an inner protruding portion 70 that protrudes inward in the radial direction y from the inner surface of the balloon 20 and extends in the longitudinal axis direction x at the portion where the protruding portion 60 is inclined. Thereby, even at the portion where the protruding portion 60 is inclined, the strength of the proximal end portion and / or the distal end portion of the balloon 2 can be improved by the inner protruding portion 70. The inner protruding portion 70 is preferably arranged at the same position as the protruding portion 60 in the circumferential direction z. Thereby, the strength of the proximal end portion and / or the distal end portion of the balloon 2 can be further improved.

[0046] The balloon 2 preferably satisfies at least one of the following (5) and (6). (5) In the cross-section in the radial direction y, the protruding portion 60 of the proximal sleeve portion 21 is inclined in the first direction d1 or the second direction d2, and a straight line L connecting the midpoint in the width direction of the proximal end 61 and the distal end 62 p and the perpendicular line L of the proximal end 61 v form an angle θ of 45° or more, In the cross-section in the radial direction y, the protruding portion 60 of the proximal tapered portion 22 is inclined in the first direction d1 or the second direction d2, and a straight line L connecting the midpoint in the width direction of the proximal end 61 and the distal end 62 p and the perpendicular line L of the proximal end 61 v form an angle of 30° or more. In the cross-section in the radial direction y, the protrusion 60 of the distal sleeve portion 25 is tilted in the first direction d1 or the second direction d2, and a straight line L connecting the midpoint in the width direction of the proximal end 61 and the distal end 62 p and the perpendicular line L to the proximal end 61 v form an angle θ of 45° or more, In the cross-section in the radial direction y, the protrusion 60 of the distal tapered portion 24 is tilted in the first direction d1 or the second direction d2, and a straight line L connecting the midpoint in the width direction of the proximal end 61 and the distal end 62 p and the perpendicular line L to the proximal end 61 v form an angle of 30° or more.

[0047] As shown in FIGS. 9 and 10, in the tapered portion, the protrusion 60 may also be tilted in the first direction d1 or the second direction d2. FIG. 9 shows a cross-section of the more distal distal tapered portion 24 in the contracted state, and FIG. 10 shows a cross-section of the more proximal distal tapered portion 24 in the contracted state. Thus, in the more distal portion, that is, the end side of the balloon 2 far from the straight tube portion 23, where the length of the blade 29 in the contracted state is short, the protrusion 60 is deeply tilted, and in the more proximal portion, that is, the straight tube portion 23 side of the balloon 2, where the length of the blade 29 in the contracted state is long, a mode in which the tilt of the protrusion 60 is shallow is also preferable. Thereby, the closer to the straight tube portion 23, the shallower the tilt of the protrusion 60, and when delivered to the lesion, the protrusion 60 disposed in the distal tapered portion 24 makes it easy to fix the balloon 2 to the lesion or incise the stenosis. This explanation can be made similarly for the proximal tapered portion 22. That is, in the more proximal portion of the proximal tapered portion 22, that is, the end of the balloon 2 far from the straight tube portion 23, where the length of the blade 29 in the contracted state is short, the protrusion 60 is deeply tilted, and in the more distal portion, that is, the straight tube portion 23 side of the balloon 2, where the length of the blade 29 in the contracted state is long, a mode in which the tilt of the protrusion 60 is shallow is also preferable. That the protrusion 60 is deeply tilted means that the distance h is short, and that the protrusion 60 is shallowly tilted means that the distance h is long. By determining how to determine the distance h, the magnitude of the cushioning property by tilting the protrusion 60 can be controlled.

[0048] Alternatively, the protrusions 60 in the tapered portion may be tilted to the same extent in the longitudinal axis direction x. Further, the protrusions 60 may have portions that are tilted and portions that are not tilted in the longitudinal axis direction x.

[0049] Due to the tilting of the protrusions 60 in the tapered portion, the protrusions 60 in the tapered portion can also function as a cushion, improving the trackability of the balloon 2. Regarding the effect of whether the protrusions 60 arranged in either the proximal tapered portion 22 and / or the distal tapered portion 24 are tilted, reference can be made to the effect of whether the protrusions 60 arranged in either the proximal sleeve portion 21 and / or the distal sleeve portion 25 are tilted.

[0050] The angle θ at which the protrusions 60 in the tapered portion are tilted is preferably 30° or more, more preferably 45° or more, still more preferably 50° or more, and may be, for example, 95° or less, 90° or less, or 80° or less.

[0051] The balloon 2 preferably satisfies at least one of (7) and (8). (7) In a cross-section in the radial direction y, the protrusion 60 of the proximal sleeve portion 21 is tilted in the first direction d1 or the second direction d2, and the straight line L p connecting the midpoint in the width direction of the proximal end 61 and the tip 62 v and the perpendicular line L of the proximal end 61 form an angle of 45° or more, p In a cross-section in the radial direction y, the protrusion 60 of the proximal tapered portion 22 is tilted in the first direction d1 or the second direction d2, and the straight line L v connecting the midpoint in the width direction of the proximal end 61 and the tip 62 and the perpendicular line L of the proximal end 61 form an angle of 30° or more, The proximal sleeve portion 21 and the proximal tapered portion 22 have an inner protrusion 70 that protrudes inward in the radial direction y from the inner surface of the balloon body 20 and extends in the longitudinal axis direction x. In a cross-section in the radial direction y, the protruding portion 60 of the distal sleeve portion 25 is tilted in the first direction d1 or the second direction d2, and a straight line L connecting the midpoint in the width direction of the proximal end 61 and the distal end 62 p and a perpendicular line L to the proximal end 61 v form an angle of 45° or more, In a cross-section in the radial direction y, the protruding portion 60 of the distal tapered portion 24 is tilted in the first direction d1 or the second direction d2, and a straight line L connecting the midpoint in the width direction of the proximal end 61 and the distal end 62 p and a perpendicular line L to the proximal end 61 v form an angle of 30° or more, The distal sleeve portion 25 and the distal tapered portion 24 have an inner protruding portion 70 that protrudes inward in the radial direction y from the inner surface of the balloon body 20 and extends in the longitudinal axis direction x.

[0052] In the portion where the protruding portion 60 arranged in the tapered portion and the sleeve portion is tilted, it is preferable to have an inner protruding portion 70 that protrudes inward in the radial direction y from the inner surface of the balloon 20 and extends in the longitudinal axis direction x. Thereby, even in the portion where the protruding portion 60 is tilted, the strength of the proximal end portion and / or the distal end portion of the balloon 2 can be improved by the inner protruding portion 70. The inner protruding portion 70 is preferably arranged at the same position as the protruding portion 60 in the circumferential direction z. Thereby, the strength of the proximal end portion and / or the distal end portion of the balloon 2 can be further improved. Although the inner protruding portion arranged in the tapered portion is not shown, reference can be made to the inner protruding portion 70 in FIG. 8.

[0053] Examples of the material constituting the balloon body 20 include polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers; polyester resins such as polyethylene terephthalate and polyester elastomers; polyurethane resins such as polyurethane and polyurethane elastomers; polyphenylene sulfide resins; polyamide resins such as polyamide and polyamide elastomers; fluorine resins; silicone resins; and natural rubbers such as latex rubber. These may be used alone or in combination of two or more. Among them, polyamide resins, polyester resins, and polyurethane resins are preferably used. In particular, it is preferable to use an elastomer resin from the viewpoints of thinning the balloon body 20 and flexibility. For example, among polyamide resins, nylon 12, nylon 11, etc. are suitable as the resin constituting the balloon body 20, and nylon 12 is more suitable because it can be formed relatively easily during blow molding. Also, from the viewpoints of thinning the balloon body 20 and flexibility, polyamide elastomers such as polyether ester amide elastomer and polyamide ether elastomer are preferably used. Among them, polyether ester amide elastomer is preferably used because of its high yield strength and good dimensional stability of the balloon body 20.

[0054] The protruding portion 60 and the inner protruding portion 70 are preferably made of the same material as the balloon body 20. If the protruding portion 60 and the inner protruding portion 70 are made of the same material as the balloon body 20, it is possible to make it difficult for the protruding portion 60 and the inner protruding portion 70 to damage the outer surface of the balloon body 20 while maintaining the flexibility of the balloon 2. The balloon body 20, the protruding portion 60, and the inner protruding portion 70 are preferably integrally formed. Thereby, it is possible to prevent the protruding portion 60 and the inner protruding portion 70 from falling off from the balloon body 20.

[0055] The balloon 2 can be manufactured by disposing a tubular parison 200 made of resin, as shown in FIG. 11 for example, in a mold having grooves in its inner cavity and performing biaxial stretch blow forming. The protrusion 60 can be formed, for example, by inserting the parison 200 into the inner cavity of the mold so that the thick portion 220 of the parison enters the grooves of the mold and introducing a fluid into the inner cavity 210 of the parison 200 to expand the parison 200. Further, when forming the inner protrusion 70, for example, by pressing the thick portion 220 of the parison 200 against a portion of the mold without grooves and introducing a fluid into the inner cavity 210 of the parison 200 to expand the parison 200, the inner protrusion 70 can be formed. As the material constituting the parison 200, reference can be made to the description of the material constituting the balloon body 20 above.

[0056] Examples of the material constituting the shaft 3 include polyamide-based resins, polyester-based resins, polyurethane-based resins, polyolefin-based resins, fluorine-based resins, vinyl chloride-based resins, silicone-based resins, natural rubbers, and the like. These may be used alone or in combination of two or more. Among them, the material constituting the shaft 3 is preferably at least one of a polyamide-based resin, a polyolefin-based resin, and a fluorine-based resin, whereby the slipperiness of the surface of the shaft 3 can be enhanced and the insertability of the balloon catheter 1 in the body cavity can be improved.

[0057] Examples of the joining of the balloon 2 and the shaft 3 include adhesion with an adhesive, welding, and caulking by attaching a ring-shaped member to a portion where the end of the balloon 2 and the shaft 3 overlap. Among them, the balloon 2 and the shaft 3 are preferably joined by welding. Since the balloon 2 and the shaft 3 are welded, the joining of the balloon 2 and the shaft 3 is difficult to be released even when the balloon 2 is repeatedly expanded and contracted, and the joining strength of the balloon 2 and the shaft 3 can be easily increased.

[0058] As shown in Fig. 1, a hub 4 may be provided on the proximal side of the shaft 3, and the hub 4 may be provided with a fluid injection portion 7 communicating with a fluid passage for supplying fluid into the balloon 2. Further, the hub 4 preferably has a guide wire insertion portion 5 communicating with an insertion passage for the guide wire. Since the balloon catheter 1 has the hub 4 provided with the fluid injection portion 7 and the guide wire insertion portion 5, operations such as supplying fluid into the balloon 2 to expand and contract the balloon 2 and delivering the balloon catheter 1 to the treatment site along the guide wire can be easily performed. Thus, not only in the so-called over-the-wire type balloon catheter in which the guide wire is inserted from the distal side to the proximal side of the shaft, but also the balloon 2 according to the embodiment of the present invention can be applied to a so-called rapid exchange type balloon catheter in which the guide wire is inserted up to the middle of the way from the distal side to the proximal side of the shaft.

[0059] The joining of the shaft 3 and the hub 4 includes, for example, adhesion with an adhesive, welding, etc. Among these, it is preferable that the shaft 3 and the hub 4 are joined by adhesion. When the shaft 3 and the hub 4 are adhered, for example, when the shaft 3 is made of a highly flexible material and the hub 4 is made of a highly rigid material, and the materials constituting the shaft 3 and the hub 4 are different, the joining strength between the shaft 3 and the hub 4 can be increased to enhance the durability of the balloon catheter 1.

Explanation of Reference Numerals

[0060] 1: Balloon catheter 2: Balloon 3: Shaft 4: Hub 5: Guide wire insertion portion 7: Fluid injection portion 20: Balloon body 21: Proximal sleeve portion 22: Proximal tapered portion 23: Straight tube portion 24: Distal tapered portion 25: Distal sleeve portion 29: Blade 31: Outer tube 32: Inner tube 60: Protrusion 61: Base end 62: Tip 70: Inner protrusion 200: Parison 210: Inner cavity of parison 220: Wall thickness part of parison x: Longitudinal axis direction of balloon body y: Radial direction of balloon body z: Circumferential direction of balloon body d1: First direction d2: Second direction L v : Perpendicular line at the base end L p : Straight line connecting the midpoint in the width direction at the base end and the tip θ: Angle formed by L v and L p and h: Distance from the outer surface of the balloon body to the tip in the space formed between the outer surface of the balloon body and the tip

Claims

1. A balloon for a balloon catheter having a straight tube portion, a proximal tapered portion located proximal to the straight tube portion, a proximal sleeve portion located proximal to the proximal tapered portion, a distal tapered portion located distal to the straight tube portion, and a distal sleeve portion located distal to the distal tapered portion, a balloon body having an outer surface and an inner surface, and a protruding portion protruding radially outward from the outer surface of the balloon body and extending in the longitudinal axis direction of the balloon body, in the radial cross-section, the protruding portion provided in the straight tube portion has a proximal end connected to the outer surface of the balloon body, and a distal end located radially outward of the proximal end and being the radially outer end of the protruding portion, in the radial cross-section, for the protruding portion provided in the straight tube portion, the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 10° or less, A balloon for a balloon catheter satisfying at least one of the following (1) and (2). (1) In the radial cross-section, the protruding portion provided in the proximal sleeve portion is tilted in the first direction or the second direction in the circumferential direction of the balloon body, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 45° or more. (2) In the radial cross-section, the protruding portion provided in the distal sleeve portion is tilted in the first direction or the second direction in the circumferential direction of the balloon body, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 45° or more.

2. The balloon for a balloon catheter according to Claim 1, satisfying at least one of the following (3) and (4). (3) In the radial cross-section, the protruding portion of the proximal sleeve portion is tilted in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 45° or more, the proximal sleeve portion has an inner protruding portion protruding radially inward from the inner surface of the balloon body and extending in the longitudinal axis direction. (4) In the cross-section in the radial direction, the protruding portion of the distal sleeve portion is tilted in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 45° or more. The distal sleeve portion has an inner protruding portion that protrudes radially inward of the inner surface of the balloon body and extends in the longitudinal axis direction.

3. The balloon for a balloon catheter according to claim 1, satisfying at least one of the following (5) and (6). (5) In the cross-section in the radial direction, the protruding portion of the proximal sleeve portion is tilted in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 45° or more. In the cross-section in the radial direction, the protruding portion of the proximal tapered portion is tilted in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 30° or more. (6) In the cross-section in the radial direction, the protruding portion of the distal sleeve portion is tilted in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 45° or more. In the cross-section in the radial direction, the protruding portion of the distal tapered portion is tilted in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 30° or more.

4. The balloon for a balloon catheter according to claim 1, satisfying at least one of the following (7) and (8). (7) In the cross-section in the radial direction, the protruding portion of the proximal sleeve portion is tilted in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 45° or more. In the cross-section in the radial direction, the protruding portion of the proximal tapered portion is tilted in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the distal end and the perpendicular line to the proximal end is 30° or more. The proximal sleeve portion and the proximal tapered portion have an inner protruding portion that protrudes radially inward of the inner surface of the balloon body and extends in the longitudinal axis direction. In the cross-section in the radial direction, the protrusion of the distal sleeve portion leans in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the tip end and the perpendicular line of the proximal end is 45° or more. In the cross-section in the radial direction, the protrusion of the distal tapered portion leans in the first direction or the second direction, and the angle formed by the straight line connecting the midpoint in the width direction of the proximal end and the tip end and the perpendicular line of the proximal end is 30° or more. The distal sleeve portion and the distal tapered portion have an inner protrusion that protrudes inward in the radial direction from the inner surface of the balloon body and extends in the longitudinal axis direction.

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