Balloon for balloon catheter, balloon catheter provided with same, and method for manufacturing balloon catheter

Abstract

A balloon for a balloon catheter having an outer layer (20b) and an inner layer (20a) made of a material having a lower Shore D hardness than the outer layer (20b), in which a region where a protrusion (28) is present has: an outer layer protrusion (28b) formed from the outer layer (20b) and protruding outward in the radial direction (y1); and an inner layer protruding section (28a) that is formed by the inner layer (20a) and protrudes outward in the radial direction (y1), and that protrudes outward in the radial direction (y1) in a cross-section perpendicular to the longitudinal direction (x1) of the straight pipe section (23). An angle ([theta] 1) formed by a straight line (La) connecting the two inner-layer end portions (28aB) and a straight line (Lb) connecting the inner-layer end portions (28aB) and the inner-layer top portion (28aT) in a first direction (d1) in the circumferential direction (z1) is smaller than an angle ([theta] 2) formed by a straight line (Lc) connecting the two outer-layer end portions (28bB) and a straight line (Ld) connecting the outer-layer end portions (28bB) and the outer-layer top portion (28bT) in the first direction (d1) in the circumferential direction (z1).

Description

Technical Field

[0001] The present invention relates to a balloon for a balloon catheter, a balloon catheter including the balloon for the balloon catheter, and a method for manufacturing the balloon catheter. Background Art

[0002] Diseases such as angina pectoris and myocardial infarction are caused by the formation of a stenotic portion hardened due to calcification or the like on the inner wall of a blood vessel. As one of the treatments therefor, there is angioplasty in which a balloon catheter is used to dilate the stenotic portion. Angioplasty is a minimally invasive treatment that does not require an open-chest operation such as a bypass operation and is widely performed.

[0003] In angioplasty, it is sometimes difficult to dilate a stenotic portion hardened due to calcification or the like using an ordinary balloon catheter. In addition, although a method is also used in which a stent, which is an indwelling dilatation device, is left in the stenotic portion to dilate the stenotic portion, for example, after such treatment, there is a case where an ISR (In-Stent-Restenosis) lesion occurs in which excessive proliferation of neointima of the blood vessel occurs again and stenosis of the blood vessel occurs again. In an ISR lesion, the neointima is soft and the surface is slippery, so that in the case of an ordinary balloon catheter, when the balloon is dilated, the position of the balloon sometimes deviates from the lesion portion and damages the blood vessel.

[0004] As a balloon catheter that can dilate a stenotic portion even in such lesions as calcified lesions and ISR lesions, a balloon catheter has been developed in which a protrusion, a braided layer, and a scoring element for biting into the stenotic portion are provided on the balloon. For example, Patent Document 1 discloses a balloon catheter in which a non-crystalline polymer is used for the protrusion, so that the rigidity of the protrusion is greater than that of the balloon wall and the cutting efficiency based on the protrusion is improved.

[0005] Patent Document 1: U.S. Patent Application Publication No. 2016 / 0128718

[0006] However, in the above-described conventional balloon, there is a problem that the outer shape of the protrusion is deformed when the balloon disposed in the lesion portion is pressurized and dilated. If the outer shape of the protrusion is deformed, there are problems that the protrusion is not easily bitten into the stenotic portion and it is difficult to cut the stenotic portion, and that the protrusion penetrates into an undesired place on the inner wall of the blood vessel lumen.

[0007] In addition, the above-described conventional balloon also has the following problem. When the balloon in the contracted state is inserted into a lumen such as a blood vessel and delivered to the lesion portion, or when it is pulled out from the lesion portion, the inner wall of the lumen such as a blood vessel is sometimes damaged by the protrusion provided at the portion that becomes the front end during the forward or backward movement of the balloon. Summary of the Invention

[0008] In view of the above circumstances, an object of the present invention is to provide a balloon for a balloon catheter, in which the outer shape of the protrusion is not easily deformed during balloon dilation, and which is not likely to damage the inner wall of the lumen when the balloon is inserted through a lumen such as a blood vessel and can improve the insertability into the lumen and the cutting efficiency of the stenosis, a balloon catheter including the balloon for a balloon catheter, and a method for manufacturing the balloon catheter.

[0009] The first balloon for a balloon catheter according to an embodiment of the present invention that can solve the above problems is as follows.

[0010] [1] A balloon for a balloon catheter having a longitudinal axis direction, a radial direction, and a circumferential direction, and having an outer layer and an inner layer made of a material having a Shore D hardness lower than that of the outer layer, wherein:

[0011] A straight tube portion; a proximal cone 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 cone portion; a distal cone portion located closer to the distal side than the straight tube portion; and a distal sleeve portion located closer to the distal side than the distal cone portion,

[0012] and having a protrusion that protrudes outward in the radial direction and extends in the longitudinal axis direction,

[0013] In a cross-section perpendicular to the longitudinal axis direction of the straight tube portion, the region where the protrusion exists has: an outer layer protrusion formed by the outer layer and protruding outward in the radial direction; and an inner layer protrusion formed by the inner layer and protruding outward in the radial direction,

[0014] The outer layer protrusion has: an outer layer top as the top of the outer layer protrusion; and outer layer ends respectively located on both sides in the circumferential direction of the outer layer top and at both ends in the circumferential direction of the outer layer protrusion,

[0015] The inner layer protrusion has: an inner layer top as the top of the inner layer protrusion; and inner layer ends respectively located on both sides in the circumferential direction of the inner layer top and at both ends in the circumferential direction of the inner layer protrusion,

[0016] In a cross-section perpendicular to the longitudinal axis direction of the straight tube portion, the angle formed by the straight line connecting the two inner layer ends and the straight line connecting the inner layer ends and the inner layer top in the first circumferential direction is smaller than the angle formed by the straight line connecting the two outer layer ends and the straight line connecting the outer layer ends and the outer layer top in the first circumferential direction.

[0017] [2] The balloon for a balloon catheter according to [1], wherein

[0018] In a cross-section of the straight tube portion perpendicular to the major axis direction, the top of the inner layer is located at a position radially outside the straight line connecting the two ends of the outer layer.

[0019] [3] The balloon for a balloon catheter according to [1] or [2], wherein

[0020] In a cross-section of the straight tube portion perpendicular to the major axis direction, the angle at the top of the inner layer in the triangle formed by connecting the two ends of the inner layer and the top of the inner layer is an obtuse angle.

[0021] In a cross-section of the straight tube portion perpendicular to the major axis direction, the angle at the top of the outer layer in the triangle formed by connecting the two ends of the outer layer and the top of the outer layer is an acute angle.

[0022] [4] The balloon for a balloon catheter according to any one of [1] to [3], wherein

[0023] In a cross-section of the straight tube portion perpendicular to the major axis direction, the area of the inner layer protrusion is smaller than the area of the outer layer protrusion.

[0024] [5] The balloon for a balloon catheter according to any one of [1] to [4], wherein

[0025] In a cross-section of at least one of the proximal cone portion and the distal cone portion perpendicular to the major axis direction, the angle formed by the straight line connecting the two ends of the inner layer and the straight line connecting the end of the inner layer and the top of the inner layer in the first circumferential direction is smaller than the angle formed by the straight line connecting the two ends of the outer layer and the straight line connecting the end of the outer layer and the top of the outer layer in the first circumferential direction.

[0026] [6] The balloon for a balloon catheter according to any one of [1] to [5], wherein

[0027] In a cross-section of at least one of the proximal sleeve portion and the distal sleeve portion perpendicular to the major axis direction, the angle formed by the straight line connecting the two ends of the inner layer and the straight line connecting the end of the inner layer and the top of the inner layer in the first circumferential direction is greater than the angle formed by the straight line connecting the two ends of the outer layer and the straight line connecting the end of the outer layer and the top of the outer layer in the first circumferential direction.

[0028] [7] The balloon for a balloon catheter according to any one of [1] to [5], wherein

[0029] In a cross-section perpendicular to the longitudinal axis in at least one of the proximal-side sleeve portion and the distal-side sleeve portion, the angle formed by the straight line connecting the two inner-layer end portions and the straight line connecting the inner-layer end portion and the inner-layer top portion in the first circumferential direction is smaller than the angle formed by the straight line connecting the two outer-layer end portions and the straight line connecting the outer-layer end portion and the outer-layer top portion in the first circumferential direction.

[0030] The present invention further provides a balloon catheter including a balloon for a first balloon catheter. The first balloon catheter according to an embodiment of the present invention is as follows.

[0031] [8] A balloon catheter, wherein,

[0032] it includes the balloon for a balloon catheter described in any one of the above [1] to [7].

[0033] The present invention also provides a method for manufacturing the balloon catheter described in [8]. The method for manufacturing the first balloon catheter according to an embodiment of the present invention is as follows.

[0034] [9] A method for manufacturing a balloon catheter for manufacturing the balloon catheter described in the above [8], including:

[0035] a step of preparing a preform having a radial direction, a circumferential direction, and a longitudinal axis direction and having a lumen extending in the longitudinal axis direction; and

[0036] a step of stretching the preform to manufacture a balloon having a proximal-side sleeve portion, a proximal-side tapered portion, a straight tube portion, a distal-side tapered portion, and a distal-side sleeve portion and having a protruding portion protruding outward in the radial direction and extending in the longitudinal axis direction,

[0037] the preform has an outer layer and an inner layer made of a material having a Shore D hardness lower than that of the outer layer, and has a protruding region and a non-protruding region other than the protruding region, and the protruding region includes a protruding portion protruding outward in the radial direction and extending in the longitudinal axis direction,

[0038] In a cross-section perpendicular to the longitudinal axis direction, the inner layer has a small thickness portion in the non-protruding region and a large thickness portion having a thickness thicker than that of the small thickness portion in the protruding region.

[0039] The second balloon for a balloon catheter according to an embodiment of the present invention that can solve the above problems is as follows.

[0040]

[10] A balloon for a balloon catheter having a longitudinal axis direction, a radial direction, and a circumferential direction, and having an outer layer and an inner layer made of a material having a Shore D hardness lower than that of the outer layer, and having:

[0041] A straight tube portion; a proximal-side tapered portion located on the proximal side of the straight tube portion; a proximal-side sleeve portion located on the proximal side of the proximal-side tapered portion; a distal-side tapered portion located on the distal side of the straight tube portion; and a distal-side sleeve portion located on the distal side of the distal-side tapered portion,

[0042] and having a protruding portion that protrudes outward in the radial direction and extends in the long axis direction,

[0043] In a cross-section of the straight tube portion perpendicular to the long axis direction, the region where the protruding portion exists has: an outer-layer protruding portion formed by the outer layer and protruding outward in the radial direction; and an inner-layer protruding portion formed by the inner layer and protruding outward in the radial direction,

[0044] The outer-layer protruding portion has: an outer-layer top as the top of the outer-layer protruding portion; and outer-layer ends located on both sides in the circumferential direction of the outer-layer protruding portion and at both ends in the circumferential direction of the outer-layer protruding portion,

[0045] The inner-layer protruding portion has: an inner-layer top as the top of the inner-layer protruding portion; and inner-layer ends located on both sides in the circumferential direction of the inner-layer protruding portion and at both ends in the circumferential direction of the inner-layer protruding portion,

[0046] The ratio (angle θ2 / angle θ1) of the angle θ2 formed by the straight line connecting two of the outer-layer ends and the straight line connecting the outer-layer end and the outer-layer top in the first circumferential direction in the cross-section of the straight tube portion perpendicular to the long axis direction to the angle θ1 formed by the straight line connecting two of the inner-layer ends and the straight line connecting the inner-layer end and the inner-layer top in the first circumferential direction is greater than the ratio (angle θ4 / angle θ3) of the angle θ4 formed by the straight line connecting two of the outer-layer ends and the straight line connecting the outer-layer end and the outer-layer top in the first circumferential direction to the angle θ3 formed by the straight line connecting two of the inner-layer ends and the straight line connecting the inner-layer end and the inner-layer top in the first circumferential direction in the cross-section of at least one of the proximal-side tapered portion and the distal-side tapered portion perpendicular to the long axis direction.

[0047]

[11] The balloon for a balloon catheter according to

[10] , wherein,

[0048] The ratio (angle θ2 / angle θ1) of the angle θ2 formed by the straight line connecting the two outer layer ends and the straight line connecting the outer layer end and the outer layer top in the circumferential first direction in the cross-section perpendicular to the major axis direction of the above-mentioned straight tube part with respect to the angle θ1 formed by the straight line connecting the two inner layer ends and the straight line connecting the inner layer end and the inner layer top in the circumferential first direction is greater than the ratio (angle θ6 / angle θ5) of the angle θ6 formed by the straight line connecting the two outer layer ends and the straight line connecting the outer layer end and the outer layer top in the circumferential first direction in the cross-section perpendicular to the major axis direction of at least one of the proximal side sleeve part and the distal side sleeve part with respect to the angle θ5 formed by the straight line connecting the two inner layer ends and the straight line connecting the inner layer end and the inner layer top in the circumferential first direction.

[0049]

[12] The balloon for a balloon catheter according to

[10] or

[11] , wherein,

[0050] The ratio (angle θ4 / angle θ3) of the angle θ4 formed by the straight line connecting the two outer layer ends and the straight line connecting the outer layer end and the outer layer top in the circumferential first direction in the cross-section perpendicular to the major axis direction of at least one of the proximal side conical part and the distal side conical part with respect to the angle θ3 formed by the straight line connecting the two inner layer ends and the straight line connecting the inner layer end and the inner layer top in the circumferential first direction is greater than the ratio (angle θ6 / angle θ5) of the angle θ6 formed by the straight line connecting the two outer layer ends and the straight line connecting the outer layer end and the outer layer top in the circumferential first direction in the cross-section perpendicular to the major axis direction of at least one of the proximal side sleeve part and the distal side sleeve part with respect to the angle θ5 formed by the straight line connecting the two inner layer ends and the straight line connecting the inner layer end and the inner layer top in the circumferential first direction.

[0051]

[13] The balloon for a balloon catheter according to any one of

[10] to

[12] , wherein,

[0052] The angle at the inner layer top in the triangle formed by connecting the two inner layer ends and the inner layer top in the cross-section perpendicular to the major axis direction of the straight tube part is greater than the angle at the inner layer top in the triangle formed by connecting the two inner layer ends and the inner layer top in the cross-section perpendicular to the major axis direction of at least one of the proximal side conical part and the distal side conical part.

[0053]

[14] The balloon for a balloon catheter according to any one of

[10] to

[13] , wherein,

[0054] The ratio of the area of the inner layer at the protruding portion in the cross-section perpendicular to the major axis direction of the straight tube portion described above is smaller than the ratio of the area of the inner layer at the protruding portion in the cross-section perpendicular to the major axis direction of at least one of the proximal side tapered portion and the distal side tapered portion described above.

[0055] The present invention also provides a balloon catheter including a balloon for a second balloon catheter. The second balloon catheter according to an embodiment of the present invention is as follows.

[0056]

[15] A balloon catheter, wherein,

[0057] it includes the balloon for a balloon catheter described in any one of the above

[10] to

[14] .

[0058] The present invention further provides a method for manufacturing the balloon catheter described in

[15] . The method for manufacturing the second balloon catheter according to an embodiment of the present invention is as follows.

[0059]

[16] A method for manufacturing a balloon catheter for manufacturing the balloon catheter described in the above

[15] , which includes:

[0060] a step of preparing a preform, the preform having a radial direction, a circumferential direction, and a major axis direction, and having a lumen extending along the major axis direction; and

[0061] a step of stretching the preform to manufacture a balloon, the balloon having a proximal side sleeve portion, a proximal side tapered portion, a straight tube portion, a distal side tapered portion, and a distal side sleeve portion, and having a protruding portion protruding outward in the radial direction and extending along the major axis direction,

[0062] the preform has an outer layer and an inner layer made of a material having a Shore D hardness lower than that of the outer layer, and has a protruding region and a non-protruding region other than the protruding region, the protruding region including a protruding portion protruding outward in the radial direction and extending along the major axis direction,

[0063] In a cross-section perpendicular to the major axis direction, the inner layer has a small thickness portion in the non-protruding region and a large thickness portion having a thickness thicker than that of the small thickness portion in the protruding region.

[0064] According to the balloon for the first balloon catheter and the second balloon catheter, the balloon catheter including the balloon for the first balloon catheter and the second balloon catheter, and the manufacturing method of the balloon catheter, it is possible to provide a balloon for a balloon catheter, a balloon catheter including the balloon for a balloon catheter, and a manufacturing method of a balloon catheter, in which the outer shape of the protrusion is not easily deformed when the balloon is expanded, and which is not likely to damage the inner wall of the lumen when the balloon is inserted into a lumen such as a blood vessel and can improve the insertability into the lumen and the incision efficiency of the stenosis part. Thereby, it is possible to perform efficient incision of the stenosis part while improving the safety of treatment and disposal based on the balloon catheter. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 The side view showing the balloon catheter according to one embodiment of the present invention.

[0066] Figure 2 Showing Figure 1 The II-II cross-sectional view of the shown balloon catheter.

[0067] Figure 3 Showing Figure 1 The III-III cross-sectional view of the shown balloon catheter.

[0068] Figure 4 Showing Figure 1 The IV-IV cross-sectional view of the shown balloon catheter.

[0069] Figure 5 The perspective view showing the pre-stretched parison according to one embodiment of the present invention.

[0070] Figure 6 Showing Figure 5 The VI-VI cross-sectional view of the shown parison.

[0071] Figure 7 Showing in Figure 6 The cross-sectional view perpendicular to the long axis direction of the parison mold used in the manufacture of the shown parison.

[0072] Figure 8 The cross-sectional view in the long axis direction of the mold for stretching the parison used in the manufacturing method according to the embodiment of the present invention.

[0073] Figure 9 Showing Figure 8 The IX-IX cross-sectional view of the shown mold. DETAILED DESCRIPTION OF THE INVENTION

[0074] Hereinafter, the present invention will be described based on embodiments. However, the present invention is of course not limited by the following embodiments, and can of course be appropriately modified and implemented within the scope that can conform to the gist described above / below, and they are all included in the technical scope of the present invention. In addition, in each drawing, for convenience, there are cases where hatching, component reference numerals, etc. are omitted. In such cases, please refer to the specification and other drawings. In addition, the dimensions of various components in the drawings are preferably conducive to understanding the features of the present invention, and thus there are cases where they are different from the actual dimensions.

[0075] 1. Balloon for balloon catheter

[0076] First, the balloon for the first balloon catheter will be described. The balloon for the first balloon catheter according to an embodiment of the present invention is a balloon for a balloon catheter having a longitudinal axis direction, a radial direction, and a circumferential direction, and having an outer layer and an inner layer made of a material having a Shore D hardness lower than that of the outer layer. Among them, it has: a straight tube portion; a proximal cone portion located on the proximal side of the straight tube portion; a proximal sleeve portion located on the proximal side of the proximal cone portion; a distal cone portion located on the distal side of the straight tube portion; and a distal sleeve portion located on the distal side of the distal cone portion, and has a protrusion that protrudes outward in the radial direction and extends in the longitudinal axis direction. In a cross-section perpendicular to the longitudinal axis direction of the straight tube portion, the region where the protrusion exists has: an outer layer protrusion formed by the outer layer and protruding outward in the radial direction; and an inner layer protrusion formed by the inner layer and protruding outward in the radial direction. The outer layer protrusion has: an outer layer top as the top of the outer layer protrusion; and outer layer ends located on both sides in the circumferential direction of the outer layer top and at both ends in the circumferential direction of the outer layer protrusion. The inner layer protrusion has: an inner layer top as the top of the inner layer protrusion; and inner layer ends located on both sides in the circumferential direction of the inner layer top and at both ends in the circumferential direction of the inner layer protrusion. In a cross-section perpendicular to the longitudinal axis direction of the straight tube portion, the angle formed by the straight line connecting the two inner layer ends and the straight line connecting the inner layer end and the inner layer top in the first circumferential direction is smaller than the angle formed by the straight line connecting the two outer layer ends and the straight line connecting the outer layer end and the outer layer top in the first circumferential direction.

[0077] By inserting a balloon provided at the distal end of a balloon catheter into the lumen of a blood vessel and expanding the balloon after delivering it to a stenosis, a protrusion provided on the outer side in the radial direction of the balloon bites into the stenosis to incise the stenosis, thereby expanding the stenosis by the balloon catheter. According to the above balloon for a balloon catheter, it has an outer layer and an inner layer made of a material with a Shore D hardness lower than that of the outer layer. The angle formed by the straight line connecting the two inner layer ends and the straight line connecting the inner layer end and the inner layer top in the first circumferential direction is smaller than the angle formed by the straight line connecting the two outer layer ends and the straight line connecting the outer layer end and the outer layer top in the first circumferential direction. Therefore, when the balloon is pressurized for expansion, the inner layer is more likely to extend circumferentially than the outer layer in the protrusion. In the protrusion, the inner layer preferentially extends circumferentially, the circumferential elongation of the outer layer is suppressed, and the outer shape of the protrusion is not easily deformed. Thus, it is possible to perform efficient incision of the stenosis while improving the safety of treatment and disposal based on the balloon catheter.

[0078] When the balloon is inserted into the stenosis or withdrawn from the body, it can be contracted by discharging fluid from the lumen of the balloon, and the blade-shaped portion of the balloon is wound around the shaft of the balloon catheter to reduce the outer diameter of the balloon. At this time, the protrusion provided on the expansion portion of the balloon is covered by the blade-shaped portion, and damage caused by contact between the protrusion and the blood vessel lumen wall can be prevented.

[0079] In this specification, the balloon for a balloon catheter is sometimes simply referred to as a "balloon".

[0080] Hereinafter, with reference to Figures 1 to 4 The balloon for a balloon catheter according to an embodiment of the present invention will be described. Figure 1 It is a side view of a balloon catheter according to an embodiment of the present invention. Figure 2 Indicates Figure 1 The II-II cross-sectional view of the balloon catheter shown, which is a cross-sectional view perpendicular to the long axis direction of the straight tube portion. Figure 3 Indicates Figure 1 The III-III cross-sectional view of the balloon catheter shown, which is a cross-sectional view perpendicular to the long axis direction of the distal conical portion. Figure 4 Indicates Figure 1 The IV-IV cross-sectional view of the balloon catheter shown, which is a cross-sectional view perpendicular to the long axis direction of the distal sleeve portion.

[0081] As Figure 1 Shown, the balloon 2 is used for the balloon catheter 1. The balloon 2 is connected to the distal end of the shaft 30, and the balloon 2 can be expanded by introducing fluid through the lumen of the shaft 30 and contracted by discharging the fluid. In order to control the expansion and contraction of the balloon 2, an inflator (balloon pressurizer) can be used to introduce or discharge the fluid. The fluid can be a pressurized fluid pressurized by a pump or the like. The balloon catheter 1 will be described in detail in the item "2. Balloon catheter".

[0082] The balloon 2 has a major axis direction x1, a radial direction y1 that connects the centroid of the outer edge of the balloon 2 and a point on the outer edge in a cross-section perpendicular to the major axis direction x1, and a circumferential direction z1 that follows the outer edge of the balloon 2 in a cross-section perpendicular to the major axis direction x1. In this specification, the direction on the user's hand side in the major axis direction x1 is referred to as the proximal side, and the direction opposite to the proximal side, i.e., the direction of the subject to be treated, is referred to as the distal side.

[0083] Members and parts other than the balloon 2 each have a major axis direction, a radial direction, and a circumferential direction. There are cases where they are the same as the major axis direction x1, radial direction y1, and circumferential direction z1 of the balloon 2, and there are also cases where they are different. For the sake of easy understanding in this specification, it is assumed that all members and parts have the same major axis direction, radial direction, and circumferential direction as the major axis direction x1, radial direction y1, and circumferential direction z1 of the balloon 2 for description.

[0084] As Figures 1 to 4 shown, the balloon 2 has a protrusion 28 that protrudes outward in the radial direction y1 and extends along the major axis direction x1. The protrusion 28 is a part formed to be thicker than the part of the balloon 2 where the protrusion 28 is not provided. That is, as Figures 2 to 4 shown, the protrusion 28 can also be alternatively referred to as a part that protrudes outward in the radial direction y1 from the outer surface of the balloon main body part 20 having the thickness of the part of the balloon 2 where the protrusion 28 is not provided.

[0085] The thickness of the protrusion 28 of the balloon 2 is preferably, for example, 1.2 times or more, more preferably 1.5 times or more, further preferably 1.8 times or more, 2.0 times or more, 2.5 times or more the thickness of the part of the balloon 2 where the protrusion 28 is not provided. The upper limit of the thickness of the protrusion 28 of the balloon 2 is not particularly limited. For example, it can be 30 times or less, 20 times or less, 10 times or less the thickness of the part of the balloon 2 where the protrusion 28 is not provided.

[0086] The balloon main body part 20 defines the basic shape of the balloon 2. The protrusion 28 is preferably provided on the outer side surface of the balloon main body part 20 in any pattern such as linear, dot, mesh, spiral, etc. The balloon 2 is given a scoring function by the protrusion 28, and the balloon 2 can generate cracks and expand at the calcified stenosis during angioplasty. In addition, the protrusion 28 can also contribute to the improvement of the strength of the balloon 2 and the suppression of overexpansion during pressurization.

[0087] As Figures 2 to 4As shown, there may be multiple protrusions 28 provided in the circumferential direction z1, or there may be only one. The number of protrusions 28 in the circumferential direction z1 can be more than 1, more than 2, more than 3, more than 4, more than 6. Additionally, it can also be 20 or less, 15 or less, 10 or less. When multiple protrusions 28 are provided in the circumferential direction z1, it is preferred that the multiple protrusions 28 are separated in the circumferential direction z1, and more preferably, they are arranged at equal intervals in the circumferential direction z1. It is preferred that the separation distance between the multiple protrusions 28 is longer than the maximum circumference of the protrusion 28.

[0088] The cross-sectional shape of the protrusion 28 in the cross-section perpendicular to the major axis direction x1 can be any shape. For example, it can be triangular, quadrilateral, polygonal, semi-circular, a part of a circular shape, substantially circular, fan-shaped, wedge-shaped, convex-shaped, spindle-shaped, and combinations thereof, etc. In addition, triangles, quadrilaterals, and polygons include not only shapes with distinct corner vertices and straight sides, but also so-called rounded polygons with rounded corners and shapes with at least a part of the sides being curved. Or, the cross-sectional shape of the protrusion 28 can also be an irregular shape with concavities, notches, etc.

[0089] When the protrusion 28 is formed in a linear or dot-like shape, it is preferred that the protrusion 28 is arranged to extend along the major axis direction x1. Or, the protrusion 28 can also be arranged to extend spirally around the major axis.

[0090] Although not shown, the balloon 2 can also have an inner protrusion that protrudes inward in the radial direction y1. It is preferred that the inner protrusion extends along the major axis direction x1. It is preferred that the protrusion 28 and the inner protrusion are arranged at the same position in the length direction x1 and circumferential direction z1 of the balloon 2, and it is preferred that they are integrally formed. By integrally forming the protrusion 28, the balloon main body 20, and the inner protrusion thickly, the balloon 2 can have the protrusion 28 and the inner protrusion.

[0091] The balloon 2 has an outer layer 20b and an inner layer 20a on the inner side in the radial direction compared to the outer layer 20b, and the inner layer 20a is made of a material with a Shore D hardness lower than that of the outer layer 20b. It is preferred that the balloon 2 has a double-layer structure composed of the inner layer 20a and the outer layer 20b in all parts. Specifically, it is preferred that the inner layer 20a and the outer layer 20b continuously exist throughout 360 degrees in the circumferential direction z1 at any position in the major axis direction x1. Since the outer side of the balloon 2 is formed by the outer layer 20b with a high Shore D hardness, the outer side of the balloon 2 is not easily damaged and the strength can be improved. In addition, the outer side of the protrusion 28 is also formed by the outer layer 20b with a high Shore D hardness, so the indentation function of the protrusion 28 can be improved.

[0092] The Shore D hardness of the inner layer 20a is preferably 20 or more, 25 or more, 30 or more, 35 or more, 40 or more, and further preferably 70 or less, 65 or less, 60 or less, 55 or less. The Shore D hardness of the outer layer 20b is preferably more than 70, 72 or more, 74 or more, 75 or more, and further preferably 90 or less, 85 or less, 80 or less. If the Shore D hardness of the inner layer 20a is within the above range, it can contribute to the improvement of the flexibility of the balloon 2. If the Shore D hardness of the outer layer 20b is within the above range, it can contribute to the improvement of the strength of the balloon 2 and the improvement of the scoring function of the protrusion 28.

[0093] The Shore D hardness can be measured using a D-type durometer, for example, based on the description in JIS K6253-2:2012. In addition, the Shore D hardness of each of the inner layer 20a and the outer layer 20b can also be the Shore D hardness of the material at the stage before forming the balloon 2.

[0094] As the material of the outer layer 20b, polyamide resins such as nylon 11 and nylon 12; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; and polyurethane resins are preferably used. As the material of the inner layer 20a, from the viewpoint of small Shore D hardness, a thermoplastic elastomer is preferably used, and for example, a polyamide elastomer such as a polyether block amide copolymer is preferably used.

[0095] As Figure 1 shown, the balloon 2 has a proximal end and a distal end in the long axis direction x1, and has: a straight tube portion 23; a proximal side tapered portion 22 located on the proximal side of the straight tube portion 23; a proximal side sleeve portion 21 located on the proximal side of the proximal side tapered portion 22; a distal side tapered portion 24 located on the distal side of the straight tube portion 23; and a distal side sleeve portion 25 located on the distal side of the distal side tapered portion 24. The straight tube portion 23 is preferably a substantially cylindrical shape having substantially the same diameter in the long axis direction x1, but may have different diameters in the long axis direction x1. The proximal side tapered portion 22 and the distal side tapered portion 24 are preferably formed in a substantially conical shape or a frustum of a cone shape by reducing the diameter as they are away from the straight tube portion 23. The straight tube portion 23 has the maximum diameter, so that when the balloon 2 is expanded in a diseased portion such as a stenosis, the straight tube portion 23 can fully contact the diseased portion and it is easy to perform treatment such as the expansion of the diseased portion. In addition, the proximal side tapered portion 22 and the distal side tapered portion 24 reduce the diameter, so that 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 to reduce the height difference between the shaft 30 and the balloon 2, and thus it is easy to insert the balloon 2 into the body cavity.

[0096] Preferably, the proximal-side tapered portion 22, the straight tube portion 23, and the distal-side tapered portion 24 are the portions that expand when fluid is introduced into the balloon 2. In contrast, the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 do not expand. Thus, it is possible to configure such that at least a part of the proximal-side sleeve portion 21 is fixed to the distal end portion of the shaft 30 and at least a part of the distal-side sleeve portion 25 is fixed to the inner shaft 60 described later.

[0097] Preferably, the balloon 2 has protrusions 28 in each of the regions of the proximal-side sleeve portion 21, the proximal-side tapered portion 22, the straight tube portion 23, the distal-side tapered portion 24, and the distal-side sleeve portion 25. Thus, the protrusion 28 provided on the straight tube portion 23 can contribute to the improvement of the scoring function, and the protrusions 28 provided outside the straight tube portion 23 can contribute to the improvement of the strength of the balloon 2 and the suppression of overexpansion during pressurization.

[0098] As Figure 2 shown, in the straight tube portion 23, the protrusion 28 has: a top portion 28T that is the outer end in the radial direction y1; and a base end 28B that is located on the inner side of the top portion 28T in the radial direction y1 and is connected to the outer surface of the balloon 2. If the protrusion 28 has the top portion 28T, the top portion 28T can easily cut the stenosis, and the efficiency of the cutting performed by the protrusion 28 can be improved. As Figure 3 and Figure 4 shown, in the proximal-side sleeve portion 21, the proximal-side tapered portion 22, the distal-side tapered portion 24, and the distal-side sleeve portion 25, the protrusion 28 may also have the top portion 28T.

[0099] In the protrusion 28, when it is difficult to determine the position of the top portion 28T due to processing such as deforming or removing the front-end portion on the outer side in the radial direction y1, the point where the straight line passing through the midpoint in the width direction of the base end 28B and the centroid of the outer shape of the balloon 2 in the cross-section perpendicular to the long-axis direction x1 intersects the contour line of the outer shape of the protrusion 28 can be defined as the top portion 28T. In addition, the midpoint in the width direction of the base end 28B refers to the midpoint of the line segment connecting the end portion on the first direction d1 side in the circumferential direction z1 and the end portion on the second direction d2 side in the circumferential direction z1 of the protrusion 28.

[0100] The protrusion 28 provided on the straight tube portion 23 can be tilted in either the first direction d1 or the second direction d2 in the circumferential direction z1. The protrusion 28 provided on the straight tube portion 23 is preferably tilted in either the first direction d1 or the second direction d2 in the circumferential direction z1 within a specified range of angles. Thereby, the balloon 2 can be efficiently fixed to the lesion site and the stenosis can be incised using the protrusion 28. When the protrusion 28 is tilted in either the first direction d1 or the second direction d2 in the circumferential direction z1, the straight line Lp connecting the midpoint in the width direction of the proximal end 28B and the top 28T is approximately coincident with the perpendicular line Lv of the proximal end 28B. That is, preferably, the angle formed by the straight line Lp connecting the midpoint in the width direction of the proximal end 28B and the top 28T and the perpendicular line Lv of the proximal end 28B is close to 0 degrees. It is also allowed that the absolute value of this angle is 5 degrees or less, 10 degrees or less, or 15 degrees or less. At this time, the angle formed by the above straight line Lp and the perpendicular line Lv of the proximal end 28B is the angle formed with the midpoint in the width direction of the proximal end 28B as the starting point and the straight line Lp relative to the perpendicular line Lv of the proximal end 28B in the direction in which the protrusion 28 is tilted. Here, the perpendicular line Lv is a perpendicular line drawn from the top 28T to the line segment connecting one end and the other end in the circumferential direction z1 of the proximal end 28B in the cross-section in the radial direction y. In addition, the midpoint in the width direction of the proximal end 28B is the midpoint of the line segment connecting the end on the first direction d1 side in the circumferential direction z1 and the end on the second direction d2 side in the circumferential direction z1 of the protrusion 28.

[0101] As Figure 2 shown, in the cross-section perpendicular to the major axis direction x1 of the straight tube portion 23, the region where the protrusion 28 is present has: an outer layer protrusion 28b, formed by the outer layer 20b and protruding outward in the radial direction y1; and an inner layer protrusion 28a, formed by the inner layer 20a and protruding outward in the radial direction y1.

[0102] The outer layer protrusion 28b has: an outer layer top 28bT as the top of the outer layer protrusion 28b; and outer layer ends 28bB, respectively located on both sides in the circumferential direction z1 of the outer layer top 28bT and at both ends in the circumferential direction z1 of the outer layer protrusion 28b. The inner layer protrusion 28a has: an inner layer top 28aT as the top of the inner layer protrusion 28a; and inner layer ends 28aB, respectively located on both sides in the circumferential direction z1 of the inner layer top 28aT and at both ends in the circumferential direction z1 of the inner layer protrusion 28a. That is, the outer layer protrusion 28b has 2 outer layer ends 28bB in the circumferential direction z1 and has an outer layer top 28bT between the 2 outer layer ends 28bB. The inner layer protrusion 28a has 2 inner layer ends 28aB in the circumferential direction z1 and has an inner layer top 28aT between the 2 inner layer ends 28aB.

[0103] In the protruding portion 28, when it is difficult to determine the position of the outer layer top 28bT due to processing or removal that deforms or removes the front end portion on the outer side in the radial direction y1, the point where the straight line connecting the midpoint of the line segment connecting the two outer layer end portions 28bB and the centroid of the outer shape of the balloon 2 intersects the contour line of the outer shape of the outer layer protruding portion 28 in a cross-section perpendicular to the major axis direction x1 can be defined as the outer layer top 28bT. Similarly, regarding the inner layer top 28aT, when it is difficult to determine the position of the inner layer top 28aT, the point where the straight line connecting the midpoint of the line segment connecting the two inner layer end portions 28aB and the centroid of the outer shape of the balloon 2 intersects the contour line of the outer shape of the inner layer protruding portion 28 in a cross-section perpendicular to the major axis direction x1 can be defined as the inner layer top 28aT.

[0104] As Figure 2 shown, in a cross-section of the straight tube portion 23 perpendicular to the major axis direction x1, the angle θ1 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top 28aT in the first direction d1 in the circumferential direction z1 is smaller than the angle θ2 formed by the straight line Lc connecting the two outer layer end portions 28bB and the straight line Ld connecting the outer layer end portion 28bB and the outer layer top 28bT in the first direction d1 in the circumferential direction z1.

[0105] In the straight tube portion 23, the angle θ1 formed by the straight line La passing through the inner layer protruding portion 28a and the straight line Lb is smaller than the angle θ2 formed by the straight line Lc of the outer layer protruding portion 28b and the straight line Ld. As a result, the inclination of the inner layer protruding portion 28a on the proximal end 28B side is gentler than that of the outer layer protruding portion 28b. Therefore, when the balloon 2 is pressurized and expanded, the inner layer protruding portion 28a made of a material with a Shore D hardness lower than that of the outer layer protruding portion 28b is likely to extend in the circumferential direction z1. In the protruding portion 28, the inner layer protruding portion 28a extends preferentially compared to the outer layer protruding portion 28b, so the elongation of the outer layer protruding portion 28b in the circumferential direction z1 is suppressed. As a result, deformation of the outer layer protruding portion 28b can be prevented, the outer shape of the protruding portion 28 is not easily deformed, and while improving the safety of the treatment and disposal performed by the balloon catheter 1, incision of the stenosis can be efficiently performed.

[0106] In a cross-section of the straight tube portion 23 perpendicular to the major axis direction x1, the angle θ1 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT in the first direction d1 of the circumferential direction z1 is preferably 0.98 times or less, more preferably 0.95 times or less, further preferably 0.90 times or less, and even more preferably 0.85 times or less of the angle θ2 formed by the straight line Lc connecting the two outer layer end portions 28bB and the straight line Ld connecting the outer layer end portion 28bB and the outer layer top portion 28bT in the first direction d1 of the circumferential direction z1. By setting the upper limit value of the ratio of the angle θ1 formed by the straight line La and the straight line Lb to the angle θ2 formed by the straight line Lc and the straight line Ld within the above range, the effect that the inner layer protrusion 28a is more likely to extend in the circumferential direction z1 than the outer layer protrusion 28b can be improved. In addition, in a cross-section of the straight tube portion 23 perpendicular to the major axis direction x1, the angle θ1 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT in the first direction d1 of the circumferential direction z1 is preferably 0.10 times or more, more preferably 0.15 times or more, and further preferably 0.20 times or more of the angle θ2 formed by the straight line Lc connecting the two outer layer end portions 28bB and the straight line Ld connecting the outer layer end portion 28bB and the outer layer top portion 28bT in the first direction d1 of the circumferential direction z1. By setting the lower limit value of the ratio of the angle θ1 formed by the straight line La and the straight line Lb to the angle θ2 formed by the straight line Lc and the straight line Ld within the above range, the thickness of the inner layer 20a at the inner layer top portion 28aT becomes thicker, and the inner layer protrusion 28a is less likely to break when the balloon 2 expands and the inner layer protrusion 28a extends in the circumferential direction z1.

[0107] In the cross-section of the straight tube portion 23 perpendicular to the major axis direction x1, the angle θ1 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT in the first direction d1 of the circumferential direction z1 is preferably 5 degrees or more, more preferably 10 degrees or more, and still more preferably 15 degrees or more. By setting the lower limit value of the angle θ1 in the straight tube portion 23 within the above range, it is possible to ensure the thickness of the inner layer 20a at the inner layer top portion 28aT in the protruding portion 28 of the straight tube portion 23, and it is possible to prevent the inner layer protruding portion 28a from being easily broken when the inner layer protruding portion 28a extends in the circumferential direction z1 due to the expansion of the balloon 2. In addition, in the cross-section of the straight tube portion 23 perpendicular to the major axis direction x1, the angle θ1 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT in the first direction d1 of the circumferential direction z1 is preferably 60 degrees or less, more preferably 50 degrees or less, and still more preferably 40 degrees or less. By setting the upper limit value of the angle θ1 of the straight tube portion 23 within the above range, in the protruding portion 28 of the straight tube portion 23, it is easy to make the thickness of the outer layer 20b of the outer layer top portion 28bT thicker than the thickness of the inner layer 20a at the inner layer top portion 28aT, and it is possible to increase the rigidity of the protruding portion 28 and easily bite into the stenosis portion.

[0108] In the cross-section of the straight tube portion 23 perpendicular to the major axis direction x1, the angle θ2 formed by the straight line Lc connecting the two outer layer end portions 28bB and the straight line Ld connecting the outer layer end portion 28bB and the outer layer top portion 28bT in the first direction d1 of the circumferential direction z1 is preferably 30 degrees or more, more preferably 35 degrees or more, and still more preferably 40 degrees or more. By setting the lower limit value of the angle θ2 in the straight tube portion 23 within the above range, in the protruding portion 28 of the straight tube portion 23, it is easy to make the thickness of the outer layer 20b of the outer layer top portion 28bT thick, increase the rigidity of the protruding portion 28, and it is possible to realize a protruding portion 28 that can easily cut the stenosis portion. In addition, in the cross-section of the straight tube portion 23 perpendicular to the major axis direction x1, the angle θ2 formed by the straight line Lc connecting the two outer layer end portions 28bB and the straight line Ld connecting the outer layer end portion 28bB and the outer layer top portion 28bT in the first direction d1 of the circumferential direction z1 is preferably 80 degrees or less, more preferably 75 degrees or less, and still more preferably 70 degrees or less. By setting the upper limit value of the angle θ2 of the straight tube portion 23 within the above range, it is possible to ensure the rigidity of the protruding portion 28 and make the shape of the top of the protruding portion 28 sharp, and it is possible to make the protruding portion 28 easily penetrate into the stenosis portion.

[0109] As Figure 2As shown, preferably in the straight tube portion 23, the balloon 2 as a whole has a double-layer structure composed of at least an inner layer 20a and an outer layer 20b. That is, preferably in the straight tube portion 23, from the portion of the balloon 2 where the protrusion 28 is not provided to the portion where the protrusion 28 is provided, at least the inner layer 20a and the outer layer 20b continuously exist over the entire 360 degrees in the circumferential direction z1. In the straight tube portion 23, since the balloon 2 as a whole has a double-layer structure composed of at least an inner layer 20a and an outer layer 20b, the indentation function of the protrusion 28, the strength of the balloon 2, and the insertability can be improved by the outer layer 20b with a high Shore D hardness.

[0110] The balloon 2 may further have a layer different from the inner layer 20a and the outer layer 20b. As a specific example, although not shown, it may have an innermost layer on the inner side in the radial direction y1 compared to the inner layer 20a, may have an outermost layer on the outer side in the radial direction y1 compared to the outer layer 20b, or may have an intermediate layer on the outer side in the radial direction y1 compared to the inner layer 20a and on the inner side in the radial direction y1 compared to the outer layer 20b.

[0111] Preferably, the protrusion 28 is integrally formed with the balloon main body portion 20. By integrally forming the protrusion 28 with the balloon main body portion 20, the detachment of the protrusion 28 from the balloon main body portion 20 can be prevented.

[0112] In the case where an inner protrusion is provided, it is also preferable that the inner layer 20a and the outer layer 20b of the portion of the balloon 2 where the inner protrusion is not provided and the portion where the inner protrusion is provided are continuous in the circumferential direction z1. Thereby, the inner protrusion can be integrally formed with the balloon main body portion 20, and the detachment of the inner protrusion from the balloon main body portion 20 can be prevented.

[0113] As Figure 2 shown, preferably in the cross-section perpendicular to the major axis direction x1 of the straight tube portion 23, the inner layer top 28aT is located at a position on the outer side in the radial direction y1 compared to the straight line Lc connecting the two outer layer ends 28bB. By having the inner layer top 28aT at a position on the outer side in the radial direction y1 compared to the straight line Lc connecting the two outer layer ends 28bB in the straight tube portion 23, the thickness of the inner layer 20a at the inner layer top 28aT among the protrusions 28 can be made thicker. As a result, when the balloon 2 expands, the inner layer protrusion 28a is more likely to extend in the circumferential direction z1 than the outer layer protrusion 28b, and the outer shape of the protrusion 28 is not easily deformed.

[0114] As Figure 2As shown, preferably in a cross-section of the straight tube portion 23 perpendicular to the major axis direction x1, the angle θa at the inner layer top 28aT in the triangle formed by connecting the two inner layer end portions 28aB and the inner layer top 28aT is an obtuse angle, and in a cross-section of the straight tube portion 23 perpendicular to the major axis direction x1, the angle θb at the outer layer top 28bT in the triangle formed by connecting the two outer layer end portions 28bB and the outer layer top 28bT is an acute angle. That is, preferably in the protruding portion 28 in a cross-section of the straight tube portion 23 perpendicular to the major axis direction x1, the inner angle at the top of the triangle formed by the two inner layer end portions 28aB and the inner layer top 28aT, that is, the angle θa, is an angle greater than 90 degrees and less than 180 degrees, and the inner angle at the top of the triangle formed by the two outer layer end portions 28bB and the outer layer top 28bT, that is, the angle θb, is an angle greater than 0 degrees and less than 90 degrees. By making the angle θa at the inner layer top 28aT in the triangle formed by connecting the two inner layer end portions 28aB and the inner layer top 28aT an obtuse angle, when the balloon 2 is pressurized and expanded, the entire inner layer protruding portion 28a is easily elongated in the circumferential direction z1, and the effect of preventing deformation of the shape of the protruding portion 28 can be improved. In addition, by making the angle θb at the outer layer top 28bT in the triangle formed by connecting the two outer layer end portions 28bB and the outer layer top 28bT an acute angle, the top of the protruding portion 28 becomes a sharp shape, and the protruding portion 28 is easily inserted into the stenosis. That is, by making the angle θa at the inner layer top 28aT an obtuse angle and the angle θb at the outer layer top 28bT an acute angle, the shape of the protruding portion 28 is not easily deformed when the balloon 2 is expanded, and the protruding portion 28 is easily inserted into the stenosis, and the balloon 2 with good cutting efficiency for the stenosis can be formed.

[0115] In a cross-section perpendicular to the major axis direction x1 at the straight pipe portion 23, the angle θa at the inner layer top 28aT in the triangle formed by connecting the two inner layer ends 28aB and the inner layer top 28aT is preferably 90 degrees or more, more preferably 100 degrees or more, further preferably 110 degrees or more, and even more preferably 120 degrees or more. By setting the lower limit value of the angle θa at the inner layer top 28aT within the above range, the inclination between the inner layer end 28aB and the inner layer top 28aT becomes gentle. In the inner layer protrusion 28a, the entire inner layer 20a easily extends in the circumferential direction z1, and it is easy to prevent deformation of the outer shape of the protrusion 28. The thickness of the inner layer protrusion 28a becomes thicker, and the inner layer protrusion 28a can be made to extend more easily in the circumferential direction z1 than the outer layer protrusion 28b. In addition, in a cross-section perpendicular to the major axis direction x1 of the straight pipe portion 23, the angle θa at the inner layer top 28aT in the triangle formed by connecting the two inner layer ends 28aB and the inner layer top 28aT is preferably 170 degrees or less, more preferably 160 degrees or less, further preferably 150 degrees or less, and even more preferably 130 degrees or less. By setting the upper limit value of the angle θa at the inner layer top 28aT within the above range, the thickness of the inner layer 20a at the inner layer top 28aT becomes thicker, and the inner layer protrusion 28a can be made to extend more easily in the circumferential direction z1 than the outer layer protrusion 28b.

[0116] In a cross-section perpendicular to the major axis direction x1 of the straight pipe portion 23, the angle θb at the outer layer top 28bT in the triangle formed by connecting the two outer layer ends 28bB and the outer layer top 28bT is preferably 10 degrees or more, more preferably 20 degrees or more, and further preferably 30 degrees or more. By setting the lower limit value of the angle θb at the outer layer top 28bT within the above range, the outer shape of the outer layer top 28bT is prevented from becoming too sharp, and the strength of the outer layer top 28bT is improved. Therefore, even when other objects such as the blood vessel lumen wall come into contact with the protrusion 28, the top of the protrusion 28 is not easily deformed, and the efficiency of cutting the stenosis can be improved. In addition, in a cross-section perpendicular to the major axis direction x1 of the straight pipe portion 23, the angle θb at the outer layer top 28bT in the triangle formed by connecting the two outer layer ends 28bB and the outer layer top 28bT is preferably 85 degrees or less, more preferably 80 degrees or less, and further preferably 75 degrees or less. By setting the upper limit value of the angle θb at the outer layer top 28bT within the above range, the outer layer top 28bT becomes a sharp structure, and the protrusion 28 can easily penetrate into the stenosis to improve the cutting efficiency.

[0117] As Figure 2As shown, preferably in a cross-section of the straight tube portion 23 perpendicular to the major axis direction x1, the area of the inner layer protruding portion 28a is smaller than the area of the outer layer protruding portion 28b. By having the area of the inner layer protruding portion 28a smaller than the area of the outer layer protruding portion 28b, in the protruding portion 28, the outer layer 20b exists more than the inner layer 20a. Therefore, the rigidity of the protruding portion 28 is increased by the outer layer 20b having a higher Shore D hardness than the inner layer 20a, and the protruding portion 28 can easily bite into the narrow portion, enabling efficient incision of the narrow portion.

[0118] In a cross-section of the straight tube portion 23 perpendicular to the major axis direction x1, the area of the inner layer protruding portion 28a is preferably 90% or less, more preferably 80% or less, and still more preferably 70% or less of the area of the outer layer protruding portion 28b. By setting the upper limit value of the ratio of the area of the inner layer protruding portion 28a to the area of the outer layer protruding portion 28b within the above range, in the protruding portion 28, the ratio of the existence of the outer layer 20b to the inner layer 20a increases, and the rigidity of the protruding portion 28 can be increased. In addition, in a cross-section of the straight tube portion 23 perpendicular to the major axis direction x1, the area of the inner layer protruding portion 28a is preferably 5% or more, more preferably 10% or more, and still more preferably 15% or more of the area of the outer layer protruding portion 28b. By setting the lower limit value of the ratio of the area of the inner layer protruding portion 28a to the area of the outer layer protruding portion 28b within the above range, the area of the inner layer 20a can be ensured in the protruding portion 28. When the balloon 2 expands, the inner layer protruding portion 28a is more likely to elongate preferentially than the outer layer protruding portion 28b, and the effect of preventing deformation of the shape of the protruding portion 28 can be improved.

[0119] In a cross-section of at least one of the proximal conical portion 22 and the distal conical portion 24 perpendicular to the major axis direction x1, the protruding portion 28 provided in at least one of the proximal conical portion 22 and the distal conical portion 24 can be configured not to fall toward either the first direction d1 or the second direction d2 in the circumferential direction z1, or can be configured to fall toward either the first direction d1 or the second direction d2 in the circumferential direction z1. By having the protruding portion 28 in at least one of the proximal conical portion 22 and the distal conical portion 24 not fall toward either the first direction d1 or the second direction d2 in the circumferential direction z1, the rigidity of the balloon 2 in the major axis direction x1 is increased due to the protruding portion 28 in the proximal conical portion 22 and the distal conical portion 24 where the protruding portion 28 is provided. As a result, the insertability of the balloon 2 into the blood vessel lumen can be improved. By having the protruding portion 28 in at least one of the proximal conical portion 22 and the distal conical portion 24 fall toward either the first direction d1 or the second direction d2 in the circumferential direction z1, when the balloon 2 is delivered to the lesion site, the tip 28T of the protruding portion 28 in the proximal conical portion 22 and the distal conical portion 24 is less likely to contact other objects such as the blood vessel lumen wall, and damage to the blood vessel lumen wall can be prevented.

[0120] Although not shown, in a cross-section perpendicular to the major axis direction x1 of at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24, the protruding portion 28 provided on at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24 can also have the front-end portion of the protruding portion 28 on the outer side in the radial direction y1 removed by machining such as cutting, dissolving, or crushing. By removing the front-end portion of the protruding portion 28 provided on at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24, when the balloon 2 is inserted into the blood vessel lumen, even if the protruding portions 28 of the proximal-side tapered portion 22 and the distal-side tapered portion 24 of the balloon 2 come into contact with the blood vessel lumen wall, it is possible to less likely damage the blood vessel lumen wall, and the balloon 2 can be formed to have high safety.

[0121] When the front-end portion on the outer side in the radial direction y1 of the protruding portion 28 provided on at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24 is removed, it is preferable that in at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24 where the front-end portion of the protruding portion 28 is removed, the protruding portion 28 has an outer-layer protruding portion 28b and an inner-layer protruding portion 28a. That is, it is preferable that in the protruding portion 28 provided on at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24, the outer-layer top portion 28bT is removed, and a part of the outer-layer protruding portion 28b including the outer-layer end portion 28bB is not removed. By having the protruding portion 28 have the outer-layer protruding portion 28b and the inner-layer protruding portion 28a in at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24 where the front-end portion of the protruding portion 28 is removed, even if the protruding portions 28 of the proximal-side tapered portion 22 and the distal-side tapered portion 24 come into contact with the blood vessel lumen wall, it is less likely to damage the blood vessel lumen wall, the safety of the balloon 2 is improved, and the rigidity in the major axis direction x1 of the proximal-side tapered portion 22 and the distal-side tapered portion 24 is increased by the outer layer 20b, and the insertability of the balloon 2 into the blood vessel lumen can be improved.

[0122] As Figure 3As shown, preferably in a cross-section perpendicular to the major axis direction x1 of at least one of the proximal cone portion 22 and the distal cone portion 24, the angle θ3 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT in the first direction d1 of the circumferential direction z1 is smaller than the angle θ4 formed by the straight line Lc connecting the two outer layer end portions 28bB and the straight line Ld connecting the outer layer end portion 28bB and the outer layer top portion 28bT in the first direction d1 of the circumferential direction z1. By making the angle θ3 formed by the straight line La and the straight line Lb of the inner layer protrusion 28a smaller than the angle θ4 formed by the straight line Lc and the straight line Ld of the outer layer protrusion 28b in at least one of the proximal cone portion 22 and the distal cone portion 24, the inclination of the inner layer protrusion 28a on the proximal end 28B side is gentler than the inclination of the outer layer protrusion 28b. As a result, when the balloon 2 is pressurized and expanded, even in the proximal cone portion 22 and the distal cone portion 24, the inner layer protrusion 28a is more likely to extend in the circumferential direction z1 than the outer layer protrusion 28b, and the outer shape deformation of the protrusion 28 from the proximal cone portion 22 and the distal cone portion 24 to the straight tube portion 23 can be prevented.

[0123] In a cross-section perpendicular to the major axis direction x1 in at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24, the angle θ3 formed by the straight line La connecting the two inner-layer end portions 28aB and the straight line Lb connecting the inner-layer end portion 28aB and the inner-layer top portion 28aT in the first direction d1 of the circumferential direction z1 is preferably 0.95 times or less, more preferably 0.90 times or less, and still more preferably 0.85 times or less, of the angle θ4 formed by the straight line Lc connecting the two outer-layer end portions 28bB and the straight line Ld connecting the outer-layer end portion 28bB and the outer-layer top portion 28bT in the first direction d1 of the circumferential direction z1. By setting the upper limit value of the ratio of the angle θ3 formed by the straight line La and the straight line Lb to the angle θ4 formed by the straight line Lc and the straight line Ld within the above range, the inner-layer protrusion 28a can be made to elongate more easily along the circumferential direction z1 than the outer-layer protrusion 28b. Further, in a cross-section perpendicular to the major axis direction x1 in at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24, the angle θ3 formed by the straight line La connecting the two inner-layer end portions 28aB and the straight line Lb connecting the inner-layer end portion 28aB and the inner-layer top portion 28aT in the first direction d1 of the circumferential direction z1 is preferably 0.10 times or more, more preferably 0.15 times or more, and still more preferably 0.20 times or more, of the angle θ4 formed by the straight line Lc connecting the two outer-layer end portions 28bB and the straight line Ld connecting the outer-layer end portion 28bB and the outer-layer top portion 28bT in the first direction d1 of the circumferential direction z1. By setting the lower limit value of the ratio of the angle θ3 formed by the straight line La and the straight line Lb to the angle θ4 formed by the straight line Lc and the straight line Ld within the above range, the thickness of the inner layer 20a at the inner-layer top portion 28aT can be made thicker, and when the balloon 2 expands and the inner-layer protrusion 28a elongates along the circumferential direction z1, the inner-layer protrusion 28a is not easily broken.

[0124] In a cross-section perpendicular to the major axis direction x1 of at least one of the proximal conical portion 22 and the distal conical portion 24, the angle θ3 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT in the first direction d1 in the circumferential direction z1 is preferably 10 degrees or more, more preferably 15 degrees or more, further preferably 20 degrees or more, and even more preferably 25 degrees or more. By setting the lower limit value of the angle θ3 of at least one of the proximal conical portion 22 and the distal conical portion 24 within the above range, the thickness of the inner layer 20a at the inner layer top portion 28aT can be increased in the proximal conical portion 22 and the distal conical portion 24, and the flexibility of the protrusion 28 can be improved, and the inner wall of the blood vessel lumen is not easily damaged even when it comes into contact with the inner wall of the blood vessel lumen. In addition, in a cross-section perpendicular to the major axis direction x1 of at least one of the proximal conical portion 22 and the distal conical portion 24, the angle θ3 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT in the first direction d1 in the circumferential direction z1 is preferably 65 degrees or less, more preferably 60 degrees or less, and further preferably 55 degrees or less. By setting the upper limit value of the angle θ3 of at least one of the proximal conical portion 22 and the distal conical portion 24 within the above range, the height of the protrusion 28 can be prevented from being too high in the proximal conical portion 22 and the distal conical portion 24, and the protrusion 28 is not easily brought into contact with the inner wall of the blood vessel lumen.

[0125] In a cross-section perpendicular to the major axis direction x1 of at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24, the angle θ4 formed by the straight line Lc connecting the two outer-layer end portions 28bB and the straight line Ld connecting the outer-layer end portion 28bB and the outer-layer top portion 28bT in the first direction d1 of the circumferential direction z1 is preferably 30 degrees or more, more preferably 35 degrees or more, and still more preferably 40 degrees or more. By setting the lower limit value of the angle θ4 of at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24 within the above range, the thickness of the outer layer 20b in the protruding portion 28 can be ensured in the proximal-side tapered portion 22 and the distal-side tapered portion 24, and the rigidity in the major axis direction x1 of the proximal-side tapered portion 22 and the distal-side tapered portion 24 can be increased to improve the insertability of the balloon 2 into the blood vessel lumen. In addition, in a cross-section perpendicular to the major axis direction x1 of at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24, the angle θ4 formed by the straight line Lc connecting the two outer-layer end portions 28bB and the straight line Ld connecting the outer-layer end portion 28bB and the outer-layer top portion 28bT in the first direction d1 of the circumferential direction z1 is preferably 85 degrees or more, more preferably 80 degrees or more, and still more preferably 75 degrees or more. By setting the lower limit value of the angle θ4 of at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24 within the above range, the thickness of the inner layer 20a in the protruding portion 28 can be easily thickened in the proximal-side tapered portion 22 and the distal-side tapered portion 24, and the protruding portion 28 can be formed to have high flexibility and is not likely to damage the blood vessel lumen wall even when it contacts the blood vessel lumen wall.

[0126] In a cross-section perpendicular to the major axis direction x1 of at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25, the protruding portion 28 provided in at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 may be configured not to fall in either the first direction d1 or the second direction d2 of the circumferential direction z1, or may be configured to fall in either the first direction d1 or the second direction d2 of the circumferential direction z1. By not allowing the protruding portion 28 to fall in either the first direction d1 or the second direction d2 of the circumferential direction z1 in at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25, the rigidity in the major axis direction x1 of the balloon 2 is increased by the protruding portion 28 in the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 where the protruding portion 28 is provided, and the insertability of the balloon 2 into the blood vessel lumen can be improved. By allowing the protruding portion 28 to fall in either the first direction d1 or the second direction d2 of the circumferential direction z1 in at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25, when the balloon 2 is inserted into the lesion site, the top portion 28T of the protruding portion 28 of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 is less likely to contact the blood vessel lumen wall. Therefore, damage to the blood vessel lumen wall due to the protruding portion 28 of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 can be prevented.

[0127] Although not shown, in a cross-section perpendicular to the longitudinal axis direction x1 of at least one of the proximal sleeve portion 21 and the distal sleeve portion 25, the protruding portion 28 provided in at least one of the proximal sleeve portion 21 and the distal sleeve portion 25 can also have the front end portion of the protruding portion 28 on the outer side in the radial direction y1 removed by machining such as cutting, dissolving, or crushing. By removing the front end portion of the protruding portion 28 provided in at least one of the proximal sleeve portion 21 and the distal sleeve portion 25, when the balloon 2 is inserted into the blood vessel lumen, even if the protruding portions 28 provided on the proximal sleeve portion 21 and the distal sleeve portion 25 come into contact with other objects such as the blood vessel lumen wall, it is possible to less easily damage the blood vessel lumen wall or the like. Therefore, it is possible to form a balloon 2 that is less likely to damage the blood vessel lumen wall or the like and has high safety.

[0128] When the front end portion on the outer side in the radial direction y1 of the protruding portion 28 provided in at least one of the proximal sleeve portion 21 and the distal sleeve portion 25 is removed, it is preferable that in at least one of the proximal sleeve portion 21 and the distal sleeve portion 25 where the front end portion of the protruding portion 28 has been removed, the protruding portion 28 has an outer layer protruding portion 28b and an inner layer protruding portion 28a. That is, it is preferable that in the protruding portion 28 provided in at least one of the proximal sleeve portion 21 and the distal sleeve portion 25, the outer layer top portion 28bT is removed, and a part of the outer layer protruding portion 28b including the outer layer end portion 28bB is not removed. By having the protruding portion 28 have an outer layer protruding portion 28b and an inner layer protruding portion 28a in at least one of the proximal sleeve portion 21 and the distal sleeve portion 25 where the front end portion of the protruding portion 28 has been removed, when the balloon 2 passes through the blood vessel lumen, even if the protruding portions 28 of the proximal sleeve portion 21 and the distal sleeve portion 25 come into contact with the blood vessel lumen wall, it is less likely to damage the blood vessel lumen wall, and it is possible to form a balloon 2 with high safety. Moreover, it is also possible to increase the rigidity of the proximal sleeve portion 21 and the distal sleeve portion 25 in the longitudinal axis direction x1 by the outer layer 20b and improve the insertability of the balloon 2 into the blood vessel lumen.

[0129] Preferably, in a cross-section perpendicular to the longitudinal axis direction x1 of at least one of the proximal side sleeve portion 21 and the distal side sleeve portion 25, the angle θ5 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT with respect to the first direction d1 in the circumferential direction z1 is greater than the angle θ6 formed by the straight line Lc connecting the two outer layer end portions 28bB and the straight line Ld connecting the outer layer end portion 28bB and the outer layer top portion 28bT with respect to the first direction d1 in the circumferential direction z1. By making the angle θ5 formed by the straight line La and the straight line Lb of the inner layer protrusion 28a greater than the angle θ6 formed by the straight line Lc and the straight line Ld of the outer layer protrusion 28b in at least one of the proximal side sleeve portion 21 and the distal side sleeve portion 25, the thickness of the inner layer 20a at the inner layer top portion 28aT of the protrusion 28 in the proximal side sleeve portion 21 and the distal side sleeve portion 25 becomes thicker. Since the Shore D hardness of the inner layer 20a is lower than that of the outer layer 20b, the elasticity of the protrusion 28 can be improved. As a result, when the balloon 2 is inserted into the blood vessel lumen, even if the protrusions 28 of the proximal side sleeve portion 21 and the distal side sleeve portion 25 come into contact with the blood vessel lumen wall, the blood vessel lumen wall is less likely to be damaged by the protrusions 28.

[0130] In a cross-section perpendicular to the longitudinal axis direction x1 of at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25, the angle θ5 formed by the straight line La connecting the two inner-layer end portions 28aB and the straight line Lb connecting the inner-layer end portion 28aB and the inner-layer top portion 28aT in the first direction d1 of the circumferential direction z1 is preferably 1.05 times or more, more preferably 1.10 times or more, and further preferably 1.15 times or more of the angle θ6 formed by the straight line Lc connecting the two outer-layer end portions 28bB and the straight line Ld connecting the outer-layer end portion 28bB and the outer-layer top portion 28bT in the first direction d1 of the circumferential direction z1. By setting the lower limit value of the ratio of the angle θ5 formed by the straight line La and the straight line Lb to the angle θ6 formed by the straight line Lc and the straight line Ld within the above range, the thickness of the inner layer 20a at the inner-layer top portion 28aT can be increased, and the effect of improving the elasticity of the protrusion 28 and being less likely to damage the blood vessel lumen wall can be enhanced. In addition, in a cross-section perpendicular to the longitudinal axis direction x1 of at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25, the angle θ5 formed by the straight line La connecting the two inner-layer end portions 28aB and the straight line Lb connecting the inner-layer end portion 28aB and the inner-layer top portion 28aT in the first direction d1 of the circumferential direction z1 is preferably 5 times or less, more preferably 4 times or less, and further preferably 3 times or less of the angle θ6 formed by the straight line Lc connecting the two outer-layer end portions 28bB and the straight line Ld connecting the outer-layer end portion 28bB and the outer-layer top portion 28bT in the first direction d1 of the circumferential direction z1. By setting the upper limit value of the ratio of the angle θ5 formed by the straight line La and the straight line Lb to the angle θ6 formed by the straight line Lc and the straight line Ld within the above range, the thickness of the outer-layer top portion 28bT can be maintained to a certain extent at the protrusion 28, and the rigidity in the longitudinal axis direction x1 of the balloon 2 of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 can be maintained, improving the insertability.

[0131] In a cross-section perpendicular to the longitudinal axis direction x1 of at least one of the proximal sleeve portion 21 and the distal sleeve portion 25, the angle θ5 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT in the first direction d1 in the circumferential direction z1 is preferably 10 degrees or more, more preferably 20 degrees or more, further preferably 25 degrees or more, still further preferably 30 degrees or more, and particularly preferably 35 degrees or more. By setting the lower limit value of the angle θ5 of at least one of the proximal sleeve portion 21 and the distal sleeve portion 25 within the above range, the thickness of the inner layer 20a at the inner layer top portion 28aT of the proximal sleeve portion 21 and the distal sleeve portion 25 can be made thicker, and the protrusion 28 can be made soft and formed into a protrusion 28 that is not likely to damage the blood vessel lumen wall when contacting the blood vessel lumen wall. In addition, in a cross-section perpendicular to the longitudinal axis direction x1 of at least one of the proximal sleeve portion 21 and the distal sleeve portion 25, the angle θ5 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT in the first direction d1 in the circumferential direction z1 is preferably 80 degrees or less, more preferably 75 degrees or less, further preferably 70 degrees or less, still further preferably 60 degrees or less. By setting the upper limit value of the angle θ5 of at least one of the proximal sleeve portion 21 and the distal sleeve portion 25 within the above range, the height of the protrusion 28 in the proximal sleeve portion 21 and the distal sleeve portion 25 is not likely to become too high, and the protrusion 28 is not likely to contact the blood vessel lumen wall.

[0132] In a cross-section perpendicular to the longitudinal axis direction x1 of at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25, the angle θ6 formed by the straight line Lc connecting the two outer-layer end portions 28bB and the straight line Ld connecting the outer-layer end portion 28bB and the outer-layer top portion 28bT in the first direction d1 of the circumferential direction z1 is preferably 10 degrees or more, more preferably 20 degrees or more, further preferably 30 degrees or more, still further preferably 35 degrees or more, and particularly preferably 40 degrees or more. By setting the lower limit value of the angle θ6 of at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 within the above range, in the proximal-side sleeve portion 21 and the distal-side sleeve portion 25, the thickness of the outer layer 20b in the protruding portion 28 can be ensured, the rigidity in the longitudinal axis direction x1 of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 can be improved, and the insertability of the balloon 2 into the blood vessel lumen can be enhanced. In addition, in a cross-section perpendicular to the longitudinal axis direction x1 of at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25, the angle θ6 formed by the straight line Lc connecting the two outer-layer end portions 28bB and the straight line Ld connecting the outer-layer end portion 28bB and the outer-layer top portion 28bT in the first direction d1 of the circumferential direction z1 is preferably 90 degrees or less, more preferably 85 degrees or less, further preferably 80 degrees or less. By setting the upper limit value of the angle θ6 of at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 within the above range, the thickness of the inner layer 20a in the protruding portion 28 in the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 can be increased, and the flexibility of the protruding portion 28 can be improved so that the blood vessel lumen wall is not easily damaged even when contacting the blood vessel lumen wall.

[0133] In addition, as Figure 4 shown, preferably in a cross-section perpendicular to the longitudinal axis direction x1 of at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25, the angle θ5 formed by the straight line La connecting the two inner-layer end portions 28aB and the straight line Lb connecting the inner-layer end portion 28aB and the inner-layer top portion 28aT in the first direction d1 of the circumferential direction z1 is smaller than the angle θ6 formed by the straight line Lc connecting the two outer-layer end portions 28bB and the straight line Ld connecting the outer-layer end portion 28bB and the outer-layer top portion 28bT in the first direction d1 of the circumferential direction z1. By making the angle θ5 formed by the straight line La and the straight line Lb of the inner-layer protruding portion 28a smaller than the angle θ6 formed by the straight line Lc and the straight line Ld of the outer-layer protruding portion 28b in at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25, the inclination of the inner-layer protruding portion 28a on the proximal-end 28B side is gentler than that of the outer-layer protruding portion 28b, and in the proximal-side sleeve portion 21 and the distal-side sleeve portion 25, the inner-layer protruding portion 28a is more likely to extend along the circumferential direction z1 than the outer-layer protruding portion 28b. As a result, when the balloon 2 is pressurized and expanded, the outer shape of the protruding portion 28 can be prevented from deforming in the proximal-side sleeve portion 21 and the distal-side sleeve portion 25.

[0134] Next, the balloon for the second balloon catheter will be described. In addition, in the description of the balloon for the second balloon catheter, the description of the parts that are repeated with the description of the above-mentioned balloon for the first balloon catheter will be omitted.

[0135] The balloon for the second balloon catheter according to the embodiment of the present invention has a longitudinal axis direction, a radial direction, and a circumferential direction, and has an outer layer and an inner layer made of a material having a lower Shore D hardness than the outer layer. The balloon has: a straight tube portion; a proximal cone portion located on the proximal side of the straight tube portion; a proximal sleeve portion located on the proximal side of the proximal cone portion; a distal cone portion located on the distal side of the straight tube portion; and a distal sleeve portion located on the distal side of the distal cone portion, and has a protruding portion that protrudes outward in the radial direction and extends in the longitudinal axis direction. In a cross-section perpendicular to the longitudinal axis direction of the straight tube portion, the region where the protruding portion exists has: an outer layer protruding portion formed by the outer layer and protruding outward in the radial direction; and an inner layer protruding portion formed by the inner layer and protruding outward in the radial direction. The outer layer protruding portion has: an outer layer top as the top of the outer layer protruding portion; and outer layer ends located on both sides in the circumferential direction of the outer layer protruding portion and at both ends in the circumferential direction of the outer layer protruding portion. The inner layer protruding portion has: an inner layer top as the top of the inner layer protruding portion; and inner layer ends located on both sides in the circumferential direction of the inner layer protruding portion and at both ends in the circumferential direction of the inner layer protruding portion. The ratio (angle θ2 / angle θ1) of the angle θ2 formed by the straight line connecting the two outer layer ends and the straight line connecting the outer layer end and the outer layer top in the circumferential first direction in the cross-section perpendicular to the longitudinal axis direction of the straight tube portion to the angle θ1 formed by the straight line connecting the two inner layer ends and the straight line connecting the inner layer end and the inner layer top in the circumferential first direction is greater than the ratio (angle θ4 / angle θ3) of the angle θ4 formed by the straight line connecting the two outer layer ends and the straight line connecting the outer layer end and the outer layer top in the circumferential first direction to the angle θ3 formed by the straight line connecting the two inner layer ends and the straight line connecting the inner layer end and the inner layer top in the circumferential first direction in at least one of the cross-sections perpendicular to the longitudinal axis direction of the proximal cone portion and the distal cone portion.

[0136] If the balloon advances or retracts within the blood vessel lumen, there is a concern that the inner wall of the blood vessel may be damaged due to contact between the protruding portions provided at both ends in the longitudinal axis direction of the balloon, such as the proximal cone portion and the distal cone portion, and the blood vessel lumen. However, according to the balloon for the balloon catheter described above, which has an outer layer and an inner layer made of a material with a Shore D hardness lower than that of the outer layer, the ratio of the angle θ2 of the outer layer protruding portion of the straight tube portion to the angle θ1 of the inner layer protruding portion is greater than the ratio of the angle θ4 of the outer layer protruding portion to the angle θ3 of the inner layer protruding portion in at least one of the proximal cone portion and the distal cone portion. Therefore, the cushioning property of the protruding portion can be improved in the proximal cone portion and the distal cone portion. As a result, even if the protruding portions of the proximal cone portion and the distal cone portion come into contact with the inner wall of the blood vessel lumen, it is not easy to damage the inner wall of the blood vessel lumen, and damage to the inner wall of the blood vessel can be prevented. In addition, the rigidity of the protruding portion of the straight tube portion can be made higher than that of the protruding portions of the proximal cone portion and the distal cone portion. Therefore, the insertability into the blood vessel lumen and the incision efficiency of the stenosis portion can be improved. Thus, it is possible to perform an efficient incision of the stenosis portion while improving the safety of the treatment and treatment based on the balloon catheter.

[0137] As Figure 2 and Figure 3 shown, the ratio of the angle θ2 formed by the straight line Lc connecting the two outer layer end portions 28bB and the straight line Ld connecting the outer layer end portion 28bB and the outer layer top portion 28bT in the circumferential direction z1 to the angle θ1 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT in the circumferential direction z1 (angle θ2 / angle θ1) in the cross section perpendicular to the longitudinal axis direction x1 of the straight tube portion 23 is greater than the ratio of the angle θ4 formed by the straight line Lc connecting the two outer layer end portions 28bB and the straight line Ld connecting the outer layer end portion 28bB and the outer layer top portion 28bT in the circumferential direction z1 to the angle θ3 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT in the circumferential direction z1 (angle θ4 / angle θ3) in at least one of the proximal cone portion 22 and the distal cone portion 24 in the cross section perpendicular to the longitudinal axis direction x1.

[0138] The ratio of the angle θ2 formed by the straight lines Lc and Ld of the outer protrusion 28b to the angle θ1 formed by the straight lines La and Lb of the inner protrusion 28a on the outer layer of the straight tube portion 23 is greater than the ratio of the angle θ4 formed by the straight lines Lc and Ld of the outer protrusion 28b to the angle θ3 formed by the straight lines La and Lb of the inner protrusion 28a in at least one of the proximal cone portion 22 and the distal cone portion 24. As a result, the flexibility of the protrusion 28 in the proximal cone portion 22 and the distal cone portion 24 is improved, and the cushioning property of the protrusion 28 can be improved. Consequently, when the balloon 2 advances or retreats in the blood vessel lumen, even if the protrusion 28 of the proximal cone portion 22 and the distal cone portion 24 contacts the blood vessel lumen wall, it is not easy to damage the blood vessel lumen wall, and damage to the blood vessel lumen wall can be prevented. In addition, the rigidity of the protrusion 28 of the straight tube portion 23 can be made higher than that of the protrusion 28 of the proximal cone portion 22 and the distal cone portion 24, and the insertability into the blood vessel lumen and the incision efficiency of the stenosis portion can be improved. Therefore, it is possible to perform efficient incision of the stenosis portion while improving the safety of the treatment and disposal based on the balloon catheter.

[0139] The ratio of the angle θ2 formed by the straight line Lc and the straight line Ld of the outer protrusion 28b of the straight tube portion 23 to the angle θ1 formed by the straight line La and the straight line Lb of the inner protrusion 28a is preferably 1.10 times or more, more preferably 1.15 times or more, and further preferably 1.20 times or more than the ratio of the angle θ4 formed by the straight line Lc and the straight line Ld of the outer protrusion 28b to the angle θ3 formed by the straight line La and the straight line Lb of the inner protrusion 28a in at least one of the proximal cone portion 22 and the distal cone portion 24. By setting the lower limit value of the ratio of the angle θ2 of the straight tube portion 23 to the angle θ1 and the ratio of the angle θ4 of at least one of the proximal cone portion 22 and the distal cone portion 24 to the angle θ3 within the above range, a soft protrusion 28 can be formed in the proximal cone portion 22 and the distal cone portion 24, and the cushioning property of the protrusion 28 can be improved. As a result, the effect of making the protrusion 28 of the proximal cone portion 22 and the distal cone portion 24 less likely to damage the inner wall of the blood vessel can be improved. In addition, the ratio of the angle θ2 formed by the straight line Lc and the straight line Ld of the outer protrusion 28b of the straight tube portion 23 to the angle θ1 formed by the straight line La and the straight line Lb of the inner protrusion 28a is preferably 3.0 times or less, more preferably 2.5 times or less, and further preferably 2.0 times or less than the ratio of the angle θ4 formed by the straight line Lc and the straight line Ld of the outer protrusion 28b to the angle θ3 formed by the straight line La and the straight line Lb of the inner protrusion 28a in at least one of the proximal cone portion 22 and the distal cone portion 24. By setting the upper limit value of the ratio of the angle θ2 of the straight tube portion 23 to the angle θ1 and the ratio of the angle θ4 of at least one of the proximal cone portion 22 and the distal cone portion 24 to the angle θ3 within the above range, the rigidity of the protrusion 28 can be increased in the straight tube portion 23, and the protrusion 28 of the straight tube portion 23 can easily and efficiently cut through the stenosis portion.

[0140] As Figure 2 shown, it is preferable that the angle θ1 formed by the straight line La connecting the two inner ends 28aB and the straight line Lb connecting the inner end 28aB and the inner top 28aT in the cross-section perpendicular to the long axis direction x1 of the straight tube portion 23 with respect to the first direction d1 in the circumferential direction z1 is smaller than the angle θ2 formed by the straight line Lc connecting the two outer ends 28bB and the straight line Ld connecting the outer end 28bB and the outer top 28bT with respect to the first direction d1 in the circumferential direction z1. By making the angle θ1 smaller than the angle θ2 in the straight tube portion 23, the thickness of the outer layer 20b in the protrusion 28 at the straight tube portion 23 can easily become thicker than the thickness of the inner layer 20a, and the rigidity of the protrusion 28 can be increased to easily bite into the stenosis portion.

[0141] As Figure 3As shown, it is preferable that the angle θ3 formed by the straight line La connecting the two inner-layer end portions 28aB and the straight line Lb connecting the inner-layer end portion 28aB and the inner-layer top portion 28aT in the cross-section perpendicular to the major axis direction x1 of at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24 with respect to the first direction d1 in the circumferential direction z1 is smaller than the angle θ4 formed by the straight line Lc connecting the two outer-layer end portions 28bB and the straight line Ld connecting the outer-layer end portion 28bB and the outer-layer top portion 28bT with respect to the first direction d1 in the circumferential direction z1. By making the angle θ3 smaller than the angle θ4 in at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24, it is easy to ensure the thickness of the outer layer 20b at the proximal-side tapered portion 22 and the distal-side tapered portion 24, the rigidity in the major axis direction x1 of the proximal-side tapered portion 22 and the distal-side tapered portion 24 can be increased, and the insertability of the balloon 2 into the blood vessel lumen can be easily improved.

[0142] As Figure 2 and Figure 4 shown, it is preferable that the ratio of the angle θ2 formed by the straight line Lc connecting the two outer-layer end portions 28bB and the straight line Ld connecting the outer-layer end portion 28bB and the outer-layer top portion 28bT in the cross-section perpendicular to the major axis direction x1 of the straight tube portion 23 with respect to the first direction d1 in the circumferential direction z1 to the angle θ1 formed by the straight line La connecting the two inner-layer end portions 28aB and the straight line Lb connecting the inner-layer end portion 28aB and the inner-layer top portion 28aT with respect to the first direction d1 in the circumferential direction z1 (angle θ2 / angle θ1) is greater than the ratio of the angle θ6 formed by the straight line Lc connecting the two outer-layer end portions 28bB and the straight line Ld connecting the outer-layer end portion 28bB and the outer-layer top portion 28bT in the cross-section perpendicular to the major axis direction x1 of at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 with respect to the first direction d1 in the circumferential direction z1 to the angle θ5 formed by the straight line La connecting the two inner-layer end portions 28aB and the straight line Lb connecting the inner-layer end portion 28aB and the inner-layer top portion 28aT with respect to the first direction d1 in the circumferential direction z1 (angle θ6 / angle θ5).

[0143] By making the ratio of the angle θ2 formed by the straight lines Lc and Ld of the outer protrusion 28b of the straight tube portion 23 to the angle θ1 formed by the straight lines La and Lb of the inner protrusion 28a greater than the ratio of the angle θ6 formed by the straight lines Lc and Ld of the outer protrusion 28b to the angle θ5 formed by the straight lines La and Lb of the inner protrusion 28a in at least one of the proximal sleeve portion 21 and the distal sleeve portion 25, the flexibility of the protrusion 28 can be improved in the proximal sleeve portion 21 and the distal sleeve portion 25. When the balloon 2 advances or retreats in the blood vessel lumen, the proximal sleeve portion 21 and the distal sleeve portion 25 become the leading portions. Therefore, although there is a risk of damaging the blood vessel lumen wall due to the contact between the protrusion 28 provided on the proximal sleeve portion 21 and the distal sleeve portion 25 and the blood vessel lumen, since the protrusion 28 of the proximal sleeve portion 21 and the distal sleeve portion 25 is flexible, damage to the blood vessel lumen wall can be prevented.

[0144] The ratio of the angle θ2 formed by the straight lines Lc and Ld of the outer protrusion 28b of the straight tube portion 23 to the angle θ1 formed by the straight lines La and Lb of the inner protrusion 28a is preferably 1.1 times or more, more preferably 1.2 times or more, and further preferably 1.3 times or more the ratio of the angle θ6 formed by the straight lines Lc and Ld of the outer protrusion 28b to the angle θ5 formed by the straight lines La and Lb of the inner protrusion 28a in at least one of the proximal sleeve portion 21 and the distal sleeve portion 25. By setting the lower limit value of the ratio of the angle θ2 of the straight tube portion 23 to the angle θ1 and the ratio of the angle θ6 to the angle θ5 in at least one of the proximal sleeve portion 21 and the distal sleeve portion 25 within the above range, the protrusion 28 of the proximal sleeve portion 21 and the distal sleeve portion 25 can be made more flexible than the protrusion 28 of the straight tube portion 23. As a result, the effect of being less likely to damage the blood vessel lumen wall even when the protrusion 28 of the proximal sleeve portion 21 and the distal sleeve portion 25 contacts the blood vessel lumen wall can be improved. In addition, the ratio of the angle θ2 formed by the straight lines Lc and Ld of the outer protrusion 28b of the straight tube portion 23 to the angle θ1 formed by the straight line La of the inner protrusion 28a with respect to the straight line Lb is preferably 5.0 times or less, more preferably 4.5 times or less, and further preferably 4.0 times or less the ratio of the angle θ6 formed by the straight lines Lc and Ld of the outer protrusion 28b to the angle θ5 formed by the straight lines La and Lb of the inner protrusion 28a in at least one of the proximal sleeve portion 21 and the distal sleeve portion 25. By setting the upper limit value of the ratio of the angle θ2 of the straight tube portion 23 to the angle θ1 and the ratio of the angle θ6 to the angle θ5 in at least one of the proximal sleeve portion 21 and the distal sleeve portion 25 within the above range, the rigidity of the protrusion 28 of the straight tube portion 23 can be improved, and the incision of the stenosis portion by the protrusion 28 of the straight tube portion 23 can be facilitated.

[0145] As Figure 4 shown, it is preferable that the angle θ5 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT in the cross-section perpendicular to the major axis direction x1 of at least one of the proximal side sleeve portion 21 and the distal side sleeve portion 25 with respect to the first direction d1 in the circumferential direction z1 is smaller than the angle θ6 formed by the straight line Lc connecting the two outer layer end portions 28bB and the straight line Ld connecting the outer layer end portion 28bB and the outer layer top portion 28bT with respect to the first direction d1 in the circumferential direction z1. By making the angle θ5 smaller than the angle θ6 in at least one of the proximal side sleeve portion 21 and the distal side sleeve portion 25, it is easy to ensure the thickness of the outer layer 20b in the proximal side sleeve portion 21 and the distal side sleeve portion 25, the rigidity in the major axis direction x1 of the proximal side sleeve portion 21 and the distal side sleeve portion 25 can be improved, and the insertability of the balloon 2 into the blood vessel lumen can be enhanced.

[0146] As Figure 3 and Figure 4 shown, it is preferable that the ratio of the angle θ4 formed by the straight line Lc connecting the two outer layer end portions 28bB and the straight line Ld connecting the outer layer end portion 28bB and the outer layer top portion 28bT in the cross-section perpendicular to the major axis direction x1 of at least one of the proximal side tapered portion 22 and the distal side tapered portion 24 with respect to the first direction d1 in the circumferential direction z1 to the angle θ3 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT with respect to the first direction d1 in the circumferential direction z1 (angle θ4 / angle θ3) is greater than the ratio of the angle θ6 formed by the straight line Lc connecting the two outer layer end portions 28bB and the straight line Ld connecting the outer layer end portion 28bB and the outer layer top portion 28bT in the cross-section perpendicular to the major axis direction x1 of at least one of the proximal side sleeve portion 21 and the distal side sleeve portion 25 with respect to the first direction d1 in the circumferential direction z1 to the angle θ5 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT with respect to the first direction d1 in the circumferential direction z1 (angle θ6 / angle θ5).

[0147] By making the ratio of the angle θ4 formed by the straight lines Lc and Ld of the outer layer protrusion 28b in at least one of the proximal cone portion 22 and the distal cone portion 24 to the angle θ3 formed by the straight lines La and Lb of the inner layer protrusion 28a greater than the ratio of the angle θ6 formed by the straight lines Lc and Ld of the outer layer protrusion 28b in at least one of the proximal sleeve portion 21 and the distal sleeve portion 25 to the angle θ5 formed by the straight lines La and Lb of the inner layer protrusion 28a, it is possible to further increase the flexibility of the protrusion 28 at the proximal sleeve portion 21 and the distal sleeve portion 25 compared to the protrusion 28 at the proximal cone portion 22 and the distal cone portion 24. Therefore, it is possible to make the protrusion 28 at the proximal sleeve portion 21 and the distal sleeve portion 25, which is likely to come into contact with the wall of the blood vessel lumen when the balloon 2 advances or retreats in the blood vessel lumen, less likely to damage the wall of the blood vessel lumen even when it comes into contact with the wall of the blood vessel lumen.

[0148] The ratio of the angle θ4 formed by the straight lines Lc and Ld of the outer layer protrusion 28b in at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24 to the angle θ3 formed by the straight lines La and Lb of the inner layer protrusion 28a is preferably 1.10 times or more, more preferably 1.15 times or more, and further preferably 1.20 times or more than the ratio of the angle θ6 formed by the straight lines Lc and Ld of the outer layer protrusion 28b in at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 to the angle θ5 formed by the straight lines La and Lb of the inner layer protrusion 28a. By setting the lower limit value of the ratio of the angle θ4 to the angle θ3 in at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24 and the ratio of the angle θ6 to the angle θ5 in at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 within the above range, the protrusions 28 of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 can be made softer than the protrusions 28 of the proximal-side tapered portion 22 and the distal-side tapered portion 24, and the effect of being less likely to damage the blood vessel lumen wall even when the protrusions 28 of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 come into contact with the blood vessel lumen wall can be improved. In addition, the ratio of the angle θ4 formed by the straight lines Lc and Ld of the outer layer protrusion 28b in at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24 to the angle θ3 formed by the straight lines La and Lb of the inner layer protrusion 28a is preferably 5.0 times or less, more preferably 4.5 times or less, and further preferably 4.0 times or less than the ratio of the angle θ6 formed by the straight lines Lc and Ld of the outer layer protrusion 28b in at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 to the angle θ5 formed by the straight lines La and Lb of the inner layer protrusion 28a. By setting the upper limit value of the ratio of the angle θ4 to the angle θ3 in at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24 and the ratio of the angle θ6 to the angle θ5 in at least one of the proximal-side sleeve portion 21 and the distal-side sleeve portion 25 within the above range, the rigidity of the protrusions 28 at the proximal-side tapered portion 22 and the distal-side tapered portion 24 can be improved, and the rigidity in the long axis direction x1 of the balloon 2 can be improved to enhance the insertability.

[0149] As Figure 2 and Figure 3As shown, preferably, the angle θa at the inner layer top 28aT in the triangle formed by connecting the two inner layer ends 28aB and the inner layer top 28aT in the cross-section perpendicular to the major axis direction x1 of the straight pipe portion 23 is greater than the angle θa at the inner layer top 28aT in the triangle formed by connecting the two inner layer ends 28aB and the inner layer top 28aT in the cross-section perpendicular to the major axis direction x1 of at least one of the proximal cone portion 22 and the distal cone portion 24. By making the angle θa at the inner layer top 28aT of the straight pipe portion 23 greater than the angle θa at the inner layer top 28aT of at least one of the proximal cone portion 22 and the distal cone portion 24, the thickness of the outer layer 20b of the protruding portion 28 in the straight pipe portion 23 is likely to become thicker, and the rigidity of the protruding portion 28 is increased, making it easier to bite into the narrow portion. In addition, in the proximal cone portion 22 and the distal cone portion 24, the thickness of the inner layer 20a of the protruding portion 28 is likely to become thicker, and the flexibility of the protruding portion 28 can be improved so that the blood vessel lumen wall is not easily damaged even when it contacts the blood vessel lumen wall.

[0150] The angle θa at the inner layer top 28aT in the triangle formed by connecting the two inner layer ends 28aB and the inner layer top 28aT in the cross-section perpendicular to the major axis direction x1 of the straight pipe portion 23 is preferably 1.1 times or more, more preferably 1.2 times or more, and further preferably 1.3 times or more of the angle θa at the inner layer top 28aT in the triangle formed by connecting the two inner layer ends 28aB and the inner layer top 28aT in the cross-section perpendicular to the major axis direction x1 of at least one of the proximal cone portion 22 and the distal cone portion 24. By setting the lower limit value of the ratio of the angle θa at the inner layer top 28aT of the straight pipe portion 23 to the angle θa at the inner layer top 28aT of at least one of the proximal cone portion 22 and the distal cone portion 24 within the above range, the thickness of the outer layer 20b of the protruding portion 28 at the straight pipe portion 23 can be made thicker compared to at least one of the proximal cone portion 22 and the distal cone portion 24, and the rigidity of the protruding portion 28 can be easily increased. In addition, the angle θa at the inner layer top 28aT in the triangle formed by connecting the two inner layer ends 28aB and the inner layer top 28aT in the cross-section perpendicular to the major axis direction x1 of the straight pipe portion 23 is preferably 5 times or less, more preferably 4 times or less, and further preferably 3 times or less of the angle θa at the inner layer top 28aT in the triangle formed by connecting the two inner layer ends 28aB and the inner layer top 28aT in the cross-section perpendicular to the major axis direction x1 of at least one of the proximal cone portion 22 and the distal cone portion 24. By setting the upper limit value of the ratio of the angle θa at the inner layer top 28aT of the straight pipe portion 23 to the angle θa at the inner layer top 28aT of at least one of the proximal cone portion 22 and the distal cone portion 24 within the above range, the thickness of the inner layer 20a of the protruding portion 28 at at least one of the proximal cone portion 22 and the distal cone portion 24 can be made thicker compared to the straight pipe portion 23, and the flexibility of the protruding portion 28 can be improved.

[0151] In a cross-section perpendicular to the longitudinal axis direction x1 in at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24, the angle θa at the inner-layer top 28aT in the triangle formed by connecting the two inner-layer ends 28aB and the inner-layer top 28aT is preferably 70 degrees or more, more preferably 80 degrees or more, and still more preferably 90 degrees or more. By setting the lower limit value of the angle θa at the inner-layer top 28aT in at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24 within the above range, in the protrusions 28 of the proximal-side tapered portion 22 and the distal-side tapered portion 24, the thickness of the inner layer 20a at the inner-layer top 28aT can be increased, and the flexibility of the protrusions 28 at the proximal-side tapered portion 22 and the distal-side tapered portion 24 can be improved. In addition, in a cross-section perpendicular to the longitudinal axis direction x1 in at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24, the angle θa at the inner-layer top 28aT in the triangle formed by connecting the two inner-layer ends 28aB and the inner-layer top 28aT is preferably 160 degrees or less, more preferably 150 degrees or less, and still more preferably 140 degrees or less. By setting the upper limit value of the angle θa at the inner-layer top 28aT in at least one of the proximal-side tapered portion 22 and the distal-side tapered portion 24 within the above range, in the protrusions 28 of the proximal-side tapered portion 22 and the distal-side tapered portion 24, the inner layer 20a can easily have a certain thickness in the circumferential direction z1 and exist, and the inner layer 20a is not easily broken when the balloon 2 expands.

[0152] In addition, it is also preferable that in a cross-section of the straight tube portion 23 perpendicular to the major axis direction x1, the angle θa at the inner layer top 28aT in the triangle formed by connecting the two inner layer ends 28aB and the inner layer top 28aT is an obtuse angle, and in a cross-section of at least one of the proximal cone portion 22 and the distal cone portion 24 perpendicular to the major axis direction x1, the angle θa at the inner layer top 28aT in the triangle formed by connecting the two inner layer ends 28aB and the inner layer top 28aT is an acute angle. That is, it is preferable that in the protruding portion 28 of the cross-section of the straight tube portion 23 perpendicular to the major axis direction x1, the inner angle of the top of the triangle formed by the two inner layer ends 28aB and the inner layer top 28aT at the straight tube portion 23, that is, the angle θa, is an angle greater than 90 degrees and less than 180 degrees, and the angle θa at the inner layer top 28aT in the triangle formed by connecting the two inner layer ends 28aB and the inner layer top 28aT at at least one of the proximal cone portion 22 and the distal cone portion 24 is an angle greater than 0 degrees and less than 90 degrees. By the angle θa at the inner layer top 28aT in the triangle formed by connecting the two inner layer ends 28aB and the inner layer top 28aT at the straight tube portion 23 being an obtuse angle, the thickness of the outer layer 20b in the protruding portion 28 of the straight tube portion 23 is easily thickened, and the rigidity of the protruding portion 28 can be improved and it is easy to bite into the narrow portion. In addition, by the angle θa at the inner layer top 28aT in the triangle formed by connecting the two inner layer ends 28aB and the inner layer top 28aT at at least one of the proximal cone portion 22 and the distal cone portion 24 being an acute angle, the thickness of the inner layer 20a of the protruding portion 28 of the proximal cone portion 22 and the distal cone portion 24 is easily thickened, and the flexibility of the protruding portion 28 can be improved to enhance the effect of not easily damaging the inner wall of the blood vessel lumen.

[0153] Such as Figure 2 And Figure 3As shown, it is preferable that the ratio of the area of the inner layer 20a in the protruding portion 28 in the cross-section perpendicular to the major axis direction x1 of the straight tube portion 23 is smaller than the ratio of the area of the inner layer 20a in the protruding portion 28 in the cross-section perpendicular to the major axis direction x1 of at least one of the proximal conical portion 22 and the distal conical portion 24. That is, it is preferable that the presence ratio of the inner layer 20a in the entire protruding portion 28 at the straight tube portion 23 is smaller than the presence ratio of the inner layer 20a in the entire protruding portion 28 at least at one of the proximal conical portion 22 and the distal conical portion 24. By the ratio of the area of the inner layer 20a in the protruding portion 28 at the straight tube portion 23 being smaller than the ratio of the area of the inner layer 20a in the protruding portion 28 at least at one of the proximal conical portion 22 and the distal conical portion 24, the ratio of the inner layer 20a in the protruding portion 28 at the proximal conical portion 22 and the distal conical portion 24 is higher than that in the protruding portion 28 in the straight tube portion 23, and the flexibility of the protruding portion 28 at the proximal conical portion 22 and the distal conical portion 24 can be improved. Therefore, it is possible to maintain the rigidity of the protruding portion 28 in the straight tube portion 23 to improve the efficiency of incising the stenosis, and at the same time, make the protruding portion 28 flexible at the proximal conical portion 22 and the distal conical portion 24 so that it is not easy to damage the blood vessel lumen wall even when contacting the blood vessel lumen wall.

[0154] In the cross-section perpendicular to the major axis direction x1 of the straight tube portion 23, the ratio of the area of the inner layer 20a to the area of the entire protruding portion 28 is preferably 5% or more, more preferably 10% or more, and still more preferably 15% or more. By setting the lower limit value of the ratio of the area of the inner layer 20a in the protruding portion 28 at the straight tube portion 23 within the above range, a certain amount of the inner layer 20a exists in the protruding portion 28 of the straight tube portion 23, and when the balloon 2 expands or the balloon 2 elongates in the circumferential direction z1, etc., the inner layer 20a is not easily broken in the protruding portion 28 of the straight tube portion 23. In addition, in the cross-section perpendicular to the major axis direction x1 of the straight tube portion 23, the ratio of the area of the inner layer 20a to the area of the entire protruding portion 28 is preferably 40% or less, more preferably 35% or less, and still more preferably 30% or less. By setting the upper limit value of the ratio of the area of the inner layer 20a in the protruding portion 28 at the straight tube portion 23 within the above range, the presence ratio of the outer layer 20b can be increased in the protruding portion 28 of the straight tube portion 23, and the rigidity of the protruding portion 28 of the straight tube portion 23 can be improved.

[0155] In a cross-section perpendicular to the major axis direction x1 of at least one of the proximal conical portion 22 and the distal conical portion 24, the ratio of the area of the inner layer 20a to the area of the entire protrusion 28 is preferably 10% or more, more preferably 15% or more, and further preferably 20% or more. By setting the lower limit value of the ratio of the area of the inner layer 20a in the protrusion 28 at at least one of the proximal conical portion 22 and the distal conical portion 24 within the above range, in the protrusions 28 of the proximal conical portion 22 and the distal conical portion 24, the presence ratio of the inner layer 20a can be increased, the flexibility can be improved, and the blood vessel lumen wall is not easily damaged. In addition, in a cross-section perpendicular to the major axis direction x1 of at least one of the proximal conical portion 22 and the distal conical portion 24, the ratio of the area of the inner layer 20a to the area of the entire protrusion 28 is preferably 50% or less, more preferably 45% or less, and further preferably 40% or less. By setting the upper limit value of the ratio of the area of the inner layer 20a in the protrusion 28 at at least one of the proximal conical portion 22 and the distal conical portion 24 within the above range, a certain amount of the outer layer 20b is present in the protrusions 28 of the proximal conical portion 22 and the distal conical portion 24, and the rigidity in the major axis direction x1 of the balloon 2 can be increased to improve the insertability into the blood vessel lumen.

[0156] As Figure 2 and Figure 4 shown, it is preferable that the ratio of the area of the inner layer 20a of the protrusion 28 in the cross-section perpendicular to the major axis direction x1 of the straight tube portion 23 is smaller than the ratio of the area of the inner layer 20a of the protrusion 28 in the cross-section perpendicular to the major axis direction x1 of at least one of the proximal sleeve portion 21 and the distal sleeve portion 25. That is, it is preferable that the presence ratio of the inner layer 20a in the entire protrusion 28 of the straight tube portion 23 is smaller than the presence ratio of the inner layer 20a in the entire protrusion 28 of at least one of the proximal sleeve portion 21 and the distal sleeve portion 25. By the ratio of the area of the inner layer 20a in the protrusion 28 of the straight tube portion 23 being smaller than the ratio of the area of the inner layer 20a in the protrusion 28 of at least one of the proximal sleeve portion 21 and the distal sleeve portion 25, the ratio of the inner layer 20a of the protrusion 28 in the proximal sleeve portion 21 and the distal sleeve portion 25 is higher than that of the protrusion 28 in the straight tube portion 23, and the flexibility of the protrusion 28 in the proximal sleeve portion 21 and the distal sleeve portion 25 can be improved. Therefore, even if the protrusions 28 of the proximal sleeve portion 21 and the distal sleeve portion 25 come into contact with the blood vessel lumen wall, the blood vessel lumen wall is not easily damaged, and the rigidity of the protrusion 28 can be maintained in the straight tube portion 23 to efficiently cut the stenosis.

[0157] In a cross-section perpendicular to the longitudinal axis direction x1 of at least one of the proximal sleeve portion 21 and the distal sleeve portion 25, the ratio of the area of the inner layer 20a to the area of the entire protruding portion 28 is preferably 20% or more, more preferably 25% or more, and further preferably 30% or more. By setting the lower limit value of the ratio of the area of the inner layer 20a in the protruding portion 28 of at least one of the proximal sleeve portion 21 and the distal sleeve portion 25 within the above range, in the protruding portion 28 of the proximal sleeve portion 21 and the distal sleeve portion 25, the proportion of the inner layer 20a can be increased, the flexibility can be improved, and the effect of not easily scratching the inner wall of the blood vessel can be enhanced. In addition, in a cross-section perpendicular to the longitudinal axis direction x1 of at least one of the proximal sleeve portion 21 and the distal sleeve portion 25, the ratio of the area of the inner layer 20a to the area of the entire protruding portion 28 is preferably 60% or less, more preferably 55% or less, and further preferably 50% or less. By setting the upper limit value of the ratio of the area of the inner layer 20a in the protruding portion 28 of at least one of the proximal sleeve portion 21 and the distal sleeve portion 25 within the above range, in the protruding portion 28 of the proximal sleeve portion 21 and the distal sleeve portion 25, the existence ratio of the outer layer 20b can be ensured, and the rigidity in the longitudinal axis direction x1 of the balloon 2 can be increased to improve the insertability into the blood vessel lumen.

[0158] As Figure 3 and Figure 4 shown, it is preferable that the ratio of the area of the inner layer 20a of the protruding portion 28 in a cross-section perpendicular to the longitudinal axis direction x1 of at least one of the proximal tapered portion 22 and the distal tapered portion 24 is smaller than the ratio of the area of the inner layer 20a of the protruding portion 28 in a cross-section perpendicular to the longitudinal axis direction x1 of at least one of the proximal sleeve portion 21 and the distal sleeve portion 25. That is, it is preferable that the existence ratio of the inner layer 20a in the protruding portion 28 of at least one of the proximal tapered portion 22 and the distal tapered portion 24 is smaller than the existence ratio of the inner layer 20a in the protruding portion 28 of at least one of the proximal sleeve portion 21 and the distal sleeve portion 25. By the ratio of the area of the inner layer 20a in the protruding portion 28 of at least one of the proximal tapered portion 22 and the distal tapered portion 24 being smaller than the ratio of the area of the inner layer 20a in the protruding portion 28 of at least one of the proximal sleeve portion 21 and the distal sleeve portion 25, the flexibility of the protruding portion 28 of the proximal sleeve portion 21 and the distal sleeve portion 25 can be made higher than that of the protruding portion 28 of the proximal tapered portion 22 and the distal tapered portion 24. Therefore, while ensuring the rigidity of the balloon 2 in the longitudinal axis direction x1, the flexibility of the protruding portion 28 of the proximal sleeve portion 21 and the distal sleeve portion 25, which has a high possibility of contacting the inner wall of the blood vessel when the balloon 2 advances or retreats in the blood vessel lumen, can be improved, and the inner wall of the blood vessel is not easily damaged.

[0159] 2. Balloon catheter

[0160] The first balloon catheter 1 according to an embodiment of the present invention includes the above-described balloon 2 for the first balloon catheter. In addition, the second balloon catheter 1 according to an embodiment of the present invention includes the above-described balloon 2 for the second balloon catheter. The balloon catheter 1 may include both the balloon 2 for the first balloon catheter and the balloon 2 for the second balloon catheter. Although described in the above item "1. Balloon for balloon catheter", as Figure 1 shown, the balloon 2 is connected to the distal end portion of the shaft 30.

[0161] Figure 1 illustrated, there is shown a so-called rapid exchange type balloon catheter 1 having a guide wire port 50 in the middle from the distal side to the proximal side of the shaft 30 and an inner shaft 60 functioning as a guide wire insertion passage from the guide wire port 50 to the distal side of the shaft 30. Preferably, the balloon catheter 1 has a distal shaft 31 and a proximal shaft 32, and the distal shaft 31 and the proximal shaft 32 are independent members, and the shaft 30 extending from the balloon 2 to the proximal end of the balloon catheter 1 can be formed by connecting the proximal end portion of the distal shaft 31 to the distal end portion of the proximal shaft 32. Alternatively, a single shaft 30 may extend from the balloon 2 to the proximal end of the balloon catheter 1, or the distal shaft 31 and the proximal shaft 32 may be further composed of a plurality of tube members.

[0162] Preferably, the shaft 30 has a fluid flow path and a guide wire insertion passage inside. In order to form a structure in which the shaft 30 has a fluid flow path and a guide wire insertion passage inside, for example, the following structure can be cited: an inner shaft 60 disposed inside the shaft 30 functions as a guide wire insertion passage, and the space between the shaft 30 and the inner shaft 60 functions as a fluid flow path. In the case of such a structure, preferably, the inner shaft 60 extends and protrudes from the distal end of the shaft 30 and penetrates the balloon 2, the distal side of the balloon 2 is connected to the inner shaft 60, and the proximal side of the balloon 2 is connected to the shaft 30.

[0163] Preferably, the shaft 30 is made of resin, metal, or a combination of resin and metal. By using resin as the constituent material of the shaft, it is easy to impart flexibility and elasticity to the shaft 30. In addition, by using metal as the constituent material of the shaft 30, the deliverability of the balloon catheter 1 can be improved. Examples of the resin constituting the shaft 30 include polyamide-based resins, polyester-based resins, polyurethane-based resins, polyolefin-based resins, fluorine-based resins, vinyl chloride-based resins, silicone-based resins, natural rubber, synthetic rubber, etc. These can be used alone or in combination of two or more. Examples of the metal constituting the shaft 30 include stainless steels such as SUS304 and SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, gold, Ni-Ti alloys, Co-Cr alloys, or combinations thereof. In the case where the shaft 30 is composed of a distal shaft 31 and a proximal shaft 32 which are independent members, for example, a structure can be adopted in which the distal shaft 31 is formed of resin and the proximal shaft 32 is formed of metal. In addition, the shaft 30 may have a laminated structure formed of different materials or the same material.

[0164] For the joining of the balloon 2 and the shaft 30, examples include adhesion by an adhesive, welding, and caulking by installing an annular member at a position where the end of the balloon 2 overlaps with the shaft 30. Among these, it is preferable that the balloon 2 and the shaft 30 are joined by welding. The balloon 2 and the shaft 30 are welded, so that even if the balloon 2 is repeatedly expanded or contracted, the joining of the balloon 2 and the shaft 30 is not easily released, and the joining strength can be improved.

[0165] Preferably, a distal tip member 70 is provided at the distal end of the balloon catheter 1. The distal tip member 70 can be provided at the distal end of the balloon catheter 1 by being connected to the distal end of the balloon 2 as a member independent of the inner shaft 60, or the inner shaft 60 extending distally beyond the distal end of the balloon 2 can function as the distal tip member 70.

[0166] On the inner shaft 60 inside the balloon 2, an X-ray non-permeable marker 80 can be arranged at a portion where the balloon 2 is located in the longitudinal axis direction x1, so that the position of the balloon 2 can be confirmed by X-ray fluoroscopy. The X-ray non-permeable marker 80 is preferably arranged at positions corresponding to both ends of the straight tube portion 23 of the balloon 2, or can also be arranged at a position corresponding to the center of the straight tube portion 23 in the longitudinal axis direction x1.

[0167] A hub 5 can also be provided on the proximal side of the shaft 30. Preferably, a fluid injection portion 6 communicating with the flow path of the fluid supplied to the inside of the balloon 2 is provided on the hub 5.

[0168] For the joining of the shaft 30 and the hub 5, examples include adhesion with an adhesive, welding, etc. Among these, it is preferable that the shaft 30 and the hub 5 are joined by adhesion. The shaft 30 and the hub 5 are adhered, so that, for example, when the shaft 30 is made of a material with high flexibility and the hub 5 is made of a material with high rigidity, etc., and the materials constituting the shaft 30 and the materials constituting the hub 5 are different, the joining strength of the shaft 30 and the hub 5 can be improved to improve the durability of the balloon catheter 1.

[0169] Although not shown, the present invention can also be applied to a so-called over-the-wire balloon catheter having a guide wire insertion passage from the distal side to the proximal side of the shaft. In the case of the over-the-wire type, it is preferable that the inflation lumen and the guide wire lumen extend to the hub disposed on the hand side, and the proximal openings of the respective lumens are provided in the bifurcated hub.

[0170] In the case of a rapid exchange type catheter, it is preferable to appropriately apply a coating to the outer wall of the distal shaft 31 and / or the proximal shaft 32, and it is more preferable to apply a coating to both the distal shaft 31 and the proximal shaft 32. In the case of an over-the-wire type catheter, it is preferable to appropriately apply a coating to the outer wall of the outer shaft.

[0171] The coating can be a hydrophilic coating or a hydrophobic coating according to the purpose, and can be implemented by immersing the shaft 30 in a hydrophilic coating agent or a hydrophobic coating agent, or by coating a hydrophilic coating agent or a hydrophobic coating agent on the outer wall of the shaft 30, or by covering the outer wall of the shaft 30 with a hydrophilic coating agent or a hydrophobic coating agent. The coating agent can contain a medicine, an additive.

[0172] Examples of the hydrophilic coating agent include hydrophilic polymers such as polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyvinylpyrrolidone, methyl vinyl ether maleic anhydride copolymer, or a hydrophilic coating agent made by any combination thereof.

[0173] Examples of the hydrophobic coating agent include polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), perfluoroalkoxy alkane (PFA), silicone oil, hydrophobic polyurethane resin, carbon coating, diamond coating, diamond-like carbon (DLC) coating, ceramic coating, substances with a small surface free energy capped with an alkyl group or a perfluoroalkyl group, etc.

[0174] 3. Manufacturing method of the balloon catheter

[0175] The manufacturing methods of the first balloon catheter and the second balloon catheter according to the embodiments of the present invention are the manufacturing methods of the first balloon catheter and the second balloon catheter described above, including: a step of preparing a parison, the parison having a radial direction, a circumferential direction, and a major axis direction, and having a lumen extending in the major axis direction; and a step of stretching the parison to manufacture a balloon, the balloon having a proximal sleeve portion, a proximal tapered portion, a straight tube portion, a distal tapered portion, and a distal sleeve portion, and having a protruding portion protruding outward in the radial direction and extending in the major axis direction, the parison having an outer layer and an inner layer made of a material having a Shore D hardness lower than that of the outer layer, and having a protruding region and a non-protruding region other than the protruding region, the protruding region including a protruding portion protruding outward in the radial direction and extending in the major axis direction, in a cross-section perpendicular to the major axis direction, the inner layer having a small thickness portion in the non-protruding region and a large thickness portion in the protruding region with a thickness thicker than that of the small thickness portion.

[0176] First, the balloon for the first balloon catheter will be described. In the method according to the embodiment of the present invention, the parison has an outer layer and an inner layer made of a material having a Shore D hardness lower than that of the outer layer, and has a protruding region and a non-protruding region. In a cross-section perpendicular to the major axis direction, the inner layer has a small thickness portion in the non-protruding region and a large thickness portion in the protruding region. By stretching such a parison to manufacture a balloon, it is possible to manufacture a "2. balloon catheter" having the first "1. balloon for a balloon catheter". For the first "1. balloon for a balloon catheter", the angle formed by the straight line connecting the two inner layer ends in the straight tube portion and the straight line connecting the inner layer end and the inner layer top in the first circumferential direction is smaller than the angle formed by the straight line connecting the two outer layer ends and the straight line connecting the outer layer end and the outer layer top in the first circumferential direction.

[0177] Refer to Figures 5 to 9 , the manufacturing method of the balloon catheter according to the embodiment of the present invention will be described. Figure 5 Fig. shows a perspective view of the parison before stretching according to an embodiment of the present invention. Figure 6 Indicates Figure 5 The VI-VI cross-sectional view of the parison shown in Figure 7 Indicates Figure 6 The cross-sectional view perpendicular to the major axis direction of the parison mold used for manufacturing the parison shown in Figure 8 Fig. shows a longitudinal cross-sectional view of the mold used for stretching the parison in the manufacturing method according to the embodiment of the present invention. Figure 9 Indicates Figure 8 The IX-IX cross-sectional view of the mold shown in

[0178] First, prepare the parison 200. As shown in Figure 5As shown, the parison 200 is composed of a resin and is a cylindrical member having an inner cavity 205. The parison 200 has a first end 201 and a second end 202 and extends in the long-axis direction x2 from the first end 201 toward the second end 202. The parison 200, like the balloon 2, has a radial direction y2 and a circumferential direction z2.

[0179] As Figure 6 shown, the parison 200 has: an outer layer 200b; and an inner layer 200a, which is made of a material having a Shore D hardness lower than that of the outer layer 200b. Regarding the materials constituting the inner layer 200a and the outer layer 200b and their Shore D hardnesses, reference can be made to the description of the resins constituting the inner layer 20a and the outer layer 20b and the description of their Shore D hardnesses in the item "1. Balloon for Balloon Catheter".

[0180] The parison 200 has: a protruding region R1, including a protrusion 208 that protrudes outward in the radial direction y2 and extends in the long-axis direction x2; and a non-protruding region R2 other than the protruding region R1. By stretching the parison 200, the protrusion 208 can be formed into the protrusion 28 of the balloon 2, and the portion of the non-protruding region R2 can be formed into the balloon main body portion 20 other than the protrusion 28.

[0181] As Figure 6 shown, a plurality of protrusions 208 may be provided in the circumferential direction z2. Although not shown, a single protrusion 208 may also be provided in the circumferential direction z2. When a plurality of protrusions 208 are provided in the circumferential direction z2, it is preferable that the plurality of protrusions 208 are separated in the circumferential direction z2, and it is more preferable that they are arranged at equal intervals in the circumferential direction z2.

[0182] As Figure 6 shown, in a cross section perpendicular to the long-axis direction x2, the inner layer 200a has a small-thickness portion 220 in the non-protruding region R2 and a large-thickness portion 210 having a thickness thicker than that of the small-thickness portion 220 in the protruding region R1. By the inner layer 200a having the large-thickness portion 210 in the protruding region R1, a balloon 2 can be manufactured in which the angle θ1 formed by the straight line La connecting the two inner-layer end portions 28aB in the straight tube portion 23 and the straight line Lb connecting the inner-layer end portion 28aB and the inner-layer top portion 28aT in the first direction d1 in the circumferential direction z1 is smaller than the angle θ2 formed by the straight line Lc connecting the two outer-layer end portions 28bB and the straight line Ld connecting the outer-layer end portion 28bB and the outer-layer top portion 28bT in the first direction d1 in the circumferential direction z1.

[0183] Such a parison 200 can be manufactured, for example, by extrusion molding of a resin using Figure 7 a parison mold 250 as shown. As Figure 7As shown, the mold 250 for the preform preferably has a first cylindrical member 251, a second cylindrical member 252, and a third cylindrical member 253. The first cylindrical member 251 has a cylindrical shape such that the inner cavity 205 of the preform 200 can be formed. The second cylindrical member 252 has a cylindrical shape with a protruding portion such that the thick portion 210 and the thin portion 220 of the inner layer 200a can be formed. The third cylindrical member 253 has a cylindrical shape with a protruding portion such that the protruding portion 208 can be formed. Thus, the resin for forming the inner layer 200a is introduced into the space between the outer side surface of the first cylindrical member 251 and the inner side surface of the second cylindrical member 252, and the resin for forming the outer layer 200b is introduced into the space between the outer side surface of the second cylindrical member 252 and the inner side surface of the third cylindrical member 253 for extrusion molding. Thus, a preform 200 having a protruding portion 208, an inner layer 200a, and an outer layer 200b and having a thick portion 210 in the protruding region R1 of the inner layer 200a can be manufactured.

[0184] The material constituting the mold 250 for the preform is preferably a metal, more preferably iron, copper, aluminum, or an alloy thereof. For example, as an alloy of iron, stainless steel, etc. can be cited, as an alloy of copper, brass, etc. can be cited, and as an alloy of aluminum, duralumin, etc. can be cited. Considering from the points of having sufficient conductivity, strength, and ease of processing, it is preferred that the mold 250 for the preform is made of stainless steel.

[0185] By stretching the preform 200, a balloon 2 having a proximal sleeve portion 21, a proximal tapered portion 22, a straight tube portion 23, a distal tapered portion 24, and a distal sleeve portion 25 and having a protruding portion 28 is manufactured. At this time, the mold 300 as shown can be used. Figure 8 The mold 300 has a longitudinal axis direction x3, a radial direction y3, and a circumferential direction z3, and has an inner cavity 305 that extends in the longitudinal axis direction x3 and into which the preform 200 is inserted. It is preferred to dispose a part of the preform 200 in the longitudinal axis direction x2 of the inner cavity 305 of the mold 300.

[0186] The stretching of the preform 200 is preferably biaxial stretching. The manufacture of the balloon 2 is preferably carried out by biaxial stretch blow molding of the preform 200. In the manufacture of the balloon 2, the preform 200 can be uniformly stretched by biaxially stretching the preform 200, and a balloon 2 with high overall strength and stable quality can be manufactured.

[0187] Preferably, the mold 300 has a mold straight tube portion 300C that forms the straight tube portion of the balloon 2 in the long axis direction x3, two mold tapered portions 300T that are arranged on both sides of the mold straight tube portion 300C and form the tapered portions of the balloon 2, and two mold sleeve portions 300S that are arranged on the side farther from the mold straight tube portion 300C than the mold tapered portions 300T and form the sleeve portions of the balloon 2. Thus, the straight tube portion 23 of the balloon 2 can be formed by the mold straight tube portion 300C, the proximal tapered portion 22 and the distal tapered portion 24 can be formed by the mold tapered portions 300T, and the proximal sleeve portion 21 and the distal sleeve portion 25 can be formed by the mold sleeve portions 300S.

[0188] The mold 300 may be composed of one member or multiple members. As Figure 8 shown, it may be composed of multiple mold members connected to each other in the long axis direction x3. For example, the mold straight tube portion 300C, the mold tapered portion 300T, and the mold sleeve portion 300S may be different mold members and they are connected to each other in the long axis direction x3. In addition, the mold 300 may also be divided in the radial direction y. Thus, it is easy to insert the preform 200 into the inner cavity 305 of the mold 300. As Figure 8 shown, each mold member can be joined by engaging adjacent mold members with each other. Although not shown, magnets may also be installed on each of the adjacent mold members to be joined by the attraction of the magnets.

[0189] As Figure 9 shown, preferably, the inner cavity 305 of the mold 300 is formed by a groove portion 310 and a cylindrical wall portion 320 other than the groove portion 310, wherein the groove portion 310 is recessed outward in the radial direction y3 and extends in the long axis direction x3. Thus, the protruding portion 208 of the preform 200 can enter the groove portion 310 to form the protruding portion 28 of the balloon 2. Multiple groove portions 310 may be provided in the circumferential direction z3. Although not shown, a single groove portion 310 may also be provided in the circumferential direction z3. When multiple groove portions 310 are provided in the circumferential direction z3, preferably, the groove portions 310 are separated in the circumferential direction z3, and more preferably, they are arranged at equal intervals in the circumferential direction z3.

[0190] The groove portion 310 is preferably provided in the mold straight tube portion 300C, and may also be provided in the mold tapered portion 300T or the mold sleeve portion 300S. By providing the groove portion 310 in the mold straight tube portion 300C, the protruding portion 28 can be formed in the straight tube portion 23 of the balloon 2, and the cutting efficiency of the balloon 2 for the stenosis can be improved. The depth of the groove portion 310 provided in the mold tapered portion 300T or the mold sleeve portion 300S may be shallower than the depth of the groove portion 310 provided in the mold straight tube portion 300C, or may be equal.

[0191] The material forming the mold 300 is preferably a metal, more preferably iron, copper, aluminum, or an alloy thereof. For example, as an alloy of iron, stainless steel, etc. can be cited; as an alloy of copper, brass, etc. can be cited; as an alloy of aluminum, duralumin, etc. can be cited. Considering from the viewpoints of having sufficient electrical conductivity, strength, and ease of processing, the preform mold 300 is preferably made of stainless steel.

[0192] Next, a method for manufacturing the second balloon catheter will be described. In addition, in the description of the method for manufacturing the second balloon catheter, the description of the parts that are repeated with the description of the method for manufacturing the above-mentioned first balloon catheter will be omitted.

[0193] In the method according to the embodiment of the present invention, the preform has an outer layer and an inner layer made of a material having a lower Shore D hardness than the outer layer, and has a protruding region and a non-protruding region. In a cross-section perpendicular to the long axis direction, the inner layer has a small thickness portion in the non-protruding region and a large thickness portion in the protruding region. By biaxially stretching such a preform to manufacture a balloon, a "2. balloon catheter" having a second "1. balloon for a balloon catheter" can be manufactured. For the second "1. balloon for a balloon catheter", the ratio of the angle θ2 formed by the straight line connecting the two outer layer ends at the straight tube portion and the straight line connecting the outer layer end and the outer layer top in the first circumferential direction to the angle θ1 formed by the straight line connecting the two inner layer ends and the straight line connecting the inner layer end and the inner layer top in the first circumferential direction is greater than the ratio of the angle θ4 formed by the straight line connecting the two outer layer ends at at least one of the proximal cone portion and the distal cone portion and the straight line connecting the outer layer end and the outer layer top in the first circumferential direction to the angle θ3 formed by the straight line connecting the two inner layer ends and the straight line connecting the inner layer end and the inner layer top in the first circumferential direction.

[0194] As Figure 6As shown, in a cross-section perpendicular to the major axis direction x2, the inner layer 200a has a small thickness portion 220 in the non-projecting region R2 and a large thickness portion 210 thicker than the small thickness portion 220 in the projecting region R1. By having the large thickness portion 210 in the projecting region R1 in the inner layer 200a, it is possible to fabricate a balloon 2 in which the ratio of the angle θ2 formed by the straight line Lc connecting the two outer layer end portions 28bB at the straight tube portion 23 and the straight line Ld connecting the outer layer end portion 28bB and the outer layer top portion 28bT in the first direction d1 in the circumferential direction z1 to the angle θ1 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT in the first direction d1 in the circumferential direction z1 is greater than the ratio of the angle θ4 formed by the straight line Lc connecting the two outer layer end portions 28bB and the straight line Ld connecting the outer layer end portion 28bB and the outer layer top portion 28bT in the first direction d1 in the circumferential direction z1 to the angle θ3 formed by the straight line La connecting the two inner layer end portions 28aB and the straight line Lb connecting the inner layer end portion 28aB and the inner layer top portion 28aT in the first direction d1 in the circumferential direction z1 at at least one of the proximal side tapered portion 22 and the distal side tapered portion 24.

[0195] Such a preform 200 can be manufactured by extrusion molding of a resin using a preform mold 250 as shown above. Figure 7 shown.

[0196] This application claims the benefit of priority based on Japanese Patent Application No. 2022-183541 filed on November 16, 2022, and Japanese Patent Application No. 2022-183543 filed on November 16, 2022. The entire contents of the specifications of Japanese Patent Application No. 2022-183541 filed on November 16, 2022, and Japanese Patent Application No. 2022-183543 filed on November 16, 2022, are incorporated herein by reference.

[0197] Description of Reference Numerals

[0198] 1…Balloon catheter; 2…Balloon for balloon catheter; 5…Hub; 6…Fluid injection part; 20…Balloon main body part; 20a…Inner layer; 20b…Outer layer; 21…Proximal side sleeve part; 22…Proximal side tapered part; 23…Straight tube part; 24…Distal side tapered part; 25…Distal side sleeve part; 28…Protrusion; 28T…Top; 28B…Base end; 28a…Inner layer protrusion; 28aT…Inner layer top; 28aB…Inner layer end; 28b…Outer layer protrusion; 28bT…Outer layer top; 28bB…Outer layer end; 30…Shaft; 31…Distal side shaft; 32…Proximal side shaft; 50…Guide wire port; 60…Inner shaft; 70…Tip member; 80…Radiopaque marker; 200…Parison; 200a…Inner layer of parison; 200b…Outer layer of parison; 201…First end of parison; 202…Second end of parison; 205…Inner cavity of parison; 208…Protrusion of parison; 210…Large thickness part; 220…Small thickness part; 250…Mold for parison; 251…First cylindrical member; 252…Second cylindrical member; 253…Third cylindrical member; 300…Mold; 300C…Straight tube part of mold; 300S…Sleeve part of mold; 300T…Tapered part of mold; 305…Inner cavity of mold; 310…Groove part; 320…Cylindrical wall part; Lp…Straight line connecting the midpoint in the width direction of the base end and the top; Lv: Perpendicular line to the base end; La…Straight line connecting two inner layer ends; Lb…Straight line connecting the inner layer end and the inner layer top; Lc…Straight line connecting two outer layer ends; Ld…Straight line connecting the outer layer end and the outer layer top; θ1…Angle formed by straight line La and straight line Lb in the circumferential first direction in a cross-section perpendicular to the long axis direction in the straight tube part; θ2…Angle formed by straight line Lc and straight line Ld in the circumferential first direction in a cross-section perpendicular to the long axis direction in the straight tube part; θ3…Angle formed by straight line La and straight line Lb in the circumferential first direction in a cross-section perpendicular to the long axis direction in at least one of the proximal side tapered part and the distal side tapered part; θ4…Angle formed by straight line Lc and straight line Ld in the circumferential first direction in a cross-section perpendicular to the long axis direction in at least one of the proximal side tapered part and the distal side tapered part; θ5…Angle formed by straight line La and straight line Lb in the circumferential first direction in a cross-section perpendicular to the long axis direction in at least one of the proximal side sleeve part and the distal side sleeve part; θ6…Angle formed by straight line Lc and straight line Ld in the circumferential first direction in a cross-section perpendicular to the long axis direction in at least one of the proximal side sleeve part and the distal side sleeve part; θa…Angle at the inner layer top in the triangle formed by connecting two inner layer ends and the inner layer top; θb…Angle at the outer layer top in the triangle formed by connecting two outer layer ends and the outer layer top.

Claims

1. A balloon for a balloon catheter, having a longitudinal axis direction, a radial direction, and a circumferential direction, and having an outer layer and an inner layer made of a material with a Shore D hardness lower than that of the outer layer. The balloon for the balloon catheter is characterized by having: A straight tube portion; a proximal cone portion located on the proximal side of the straight tube portion; a proximal sleeve portion located on the proximal side of the proximal cone portion; a distal cone portion located on the distal side of the straight tube portion; and a distal sleeve portion located on the distal side of the distal cone portion. And having a protrusion that protrudes outward in the radial direction and extends in the longitudinal axis direction. In a cross-section of the straight tube portion perpendicular to the longitudinal axis direction, the region where the protrusion exists has: an outer layer protrusion formed by the outer layer and protruding outward in the radial direction; and an inner layer protrusion formed by the inner layer and protruding outward in the radial direction. The outer layer protrusion has: an outer layer top as the top of the outer layer protrusion; and outer layer ends located on both sides in the circumferential direction of the outer layer top and at both ends in the circumferential direction of the outer layer protrusion. The inner layer protrusion has: an inner layer top as the top of the inner layer protrusion; and inner layer ends located on both sides in the circumferential direction of the inner layer top and at both ends in the circumferential direction of the inner layer protrusion. In a cross-section of the straight tube portion perpendicular to the longitudinal axis direction, the angle formed by the straight line connecting the two inner layer ends and the straight line connecting the inner layer ends and the inner layer top in the first circumferential direction is smaller than the angle formed by the straight line connecting the two outer layer ends and the straight line connecting the outer layer ends and the outer layer top in the first circumferential direction.

2. The balloon for a balloon catheter according to claim 1, characterized in that In a cross-section of the straight tube portion perpendicular to the major axis direction, the top of the inner layer is located at a position radially outside of a straight line connecting the two ends of the outer layer.

3. The balloon for a balloon catheter according to claim 1 or 2, characterized in that In a cross-section of the straight tube portion perpendicular to the major axis direction, the angle at the top of the inner layer in a triangle formed by connecting the two ends of the inner layer and the top of the inner layer is an obtuse angle. In a cross-section of the straight tube portion perpendicular to the major axis direction, the angle at the top of the outer layer in a triangle formed by connecting the two ends of the outer layer and the top of the outer layer is an acute angle.

4. The balloon for a balloon catheter according to claim 1 or 2, characterized in that In a cross-section of the straight tube portion perpendicular to the major axis direction, the area of the inner layer protrusion is smaller than the area of the outer layer protrusion.

5. The balloon for a balloon catheter according to claim 1 or 2, characterized in that In a cross-section of at least one of the proximal-side tapered portion and the distal-side tapered portion perpendicular to the major axis direction, the angle formed by a straight line connecting the two ends of the inner layer and a straight line connecting the end of the inner layer and the top of the inner layer in a first circumferential direction is smaller than the angle formed by a straight line connecting the two ends of the outer layer and a straight line connecting the end of the outer layer and the top of the outer layer in the first circumferential direction.

6. The balloon for a balloon catheter according to claim 1 or 2, characterized in that In a cross-section of at least one of the proximal-side sleeve portion and the distal-side sleeve portion perpendicular to the major axis direction, the angle formed by a straight line connecting the two ends of the inner layer and a straight line connecting the end of the inner layer and the top of the inner layer in a first circumferential direction is larger than the angle formed by a straight line connecting the two ends of the outer layer and a straight line connecting the end of the outer layer and the top of the outer layer in the first circumferential direction.

7. The balloon for a balloon catheter according to claim 1 or 2, characterized in that, In a cross-section of at least one of the proximal-side sleeve portion and the distal-side sleeve portion perpendicular to the major axis direction, the angle formed by a straight line connecting the two ends of the inner layer and a straight line connecting the end of the inner layer and the top of the inner layer in a first circumferential direction is smaller than the angle formed by a straight line connecting the two ends of the outer layer and a straight line connecting the end of the outer layer and the top of the outer layer in the first circumferential direction.

8. A balloon catheter, characterized in that, The balloon for a balloon catheter according to claim 1 or 2 is provided.

9. A manufacturing method of a balloon catheter for manufacturing the balloon catheter according to claim 8, characterized in that, Comprising: A step of preparing a preform having a radial direction, a circumferential direction, and a major axis direction and having a lumen extending in the major axis direction; And A step of stretching the preform to manufacture a balloon having a proximal-side sleeve portion, a proximal-side tapered portion, a straight tube portion, a distal-side tapered portion, and a distal-side sleeve portion and having a protrusion protruding radially outward and extending in the major axis direction. The preform has an outer layer and an inner layer made of a material having a lower Shore D hardness than the outer layer, and has a protruding region and a non-protruding region other than the protruding region, and the protruding region includes a protrusion protruding radially outward and extending in the major axis direction. In a cross-section perpendicular to the major axis direction, the inner layer has a small thickness portion in the non-protruding region and a large thickness portion having a thickness thicker than that of the small thickness portion in the protruding region.

10. A balloon for a balloon catheter, having a longitudinal axis direction, a radial direction, and a circumferential direction, and having an outer layer and an inner layer made of a material with a Shore D hardness lower than that of the outer layer, The balloon for the balloon catheter is characterized by having: A straight tube portion; a proximal cone portion located on the proximal side of the straight tube portion; a proximal sleeve portion located on the proximal side of the proximal cone portion; a distal cone portion located on the distal side of the straight tube portion; and a distal sleeve portion located on the distal side of the distal cone portion, And having a protruding portion that protrudes outward in the radial direction and extends along the longitudinal axis direction, In a cross-section of the straight tube portion perpendicular to the longitudinal axis direction, the region where the protruding portion exists has: an outer layer protruding portion formed by the outer layer and protruding outward in the radial direction; and an inner layer protruding portion formed by the inner layer and protruding outward in the radial direction, The outer layer protruding portion has: an outer layer top as the top of the outer layer protruding portion; and outer layer ends located on both sides in the circumferential direction of the outer layer protruding portion and at both ends in the circumferential direction of the outer layer protruding portion, The inner layer protruding portion has: an inner layer top as the top of the inner layer protruding portion; and inner layer ends located on both sides in the circumferential direction of the inner layer protruding portion and at both ends in the circumferential direction of the inner layer protruding portion, The ratio of the angle θ2 formed by the straight line connecting the two outer ends and the straight line connecting the outer end and the outer top in the cross-section perpendicular to the major axis direction of the straight tube portion in the first circumferential direction to the angle θ1 formed by the straight line connecting the two inner ends and the straight line connecting the inner end and the inner top in the first circumferential direction, that is, the angle θ2 / angle θ1, is greater than the ratio of the angle θ4 formed by the straight line connecting the two outer ends and the straight line connecting the outer end and the outer top in the cross-section perpendicular to the major axis direction of at least one of the proximal conical portion and the distal conical portion in the first circumferential direction to the angle θ3 formed by the straight line connecting the two inner ends and the straight line connecting the inner end and the inner top in the first circumferential direction, that is, the angle θ4 / angle θ3.

11. The balloon for a balloon catheter according to claim 10, wherein The ratio of the angle θ2, which is the angle formed by the straight line connecting the two outer layer end portions and the straight line connecting the outer layer end portion and the outer layer top portion in the circumferential first direction in the cross-section perpendicular to the major axis direction of the straight tube portion, to the angle θ1, which is the angle formed by the straight line connecting the two inner layer end portions and the straight line connecting the inner layer end portion and the inner layer top portion in the circumferential first direction, that is, the angle θ2 / angle θ1, is greater than the ratio of the angle θ6, which is the angle formed by the straight line connecting the two outer layer end portions and the straight line connecting the outer layer end portion and the outer layer top portion in the circumferential first direction in the cross-section perpendicular to the major axis direction of at least one of the proximal side sleeve portion and the distal side sleeve portion, to the angle θ5, which is the angle formed by the straight line connecting the two inner layer end portions and the straight line connecting the inner layer end portion and the inner layer top portion in the circumferential first direction, that is, the angle θ6 / angle θ5.

12. The balloon for a balloon catheter according to claim 10 or 11, wherein The ratio of the angle θ4, which is the angle formed by the straight line connecting the two outer layer end portions and the straight line connecting the outer layer end portion and the outer layer top portion in the circumferential first direction in the cross-section perpendicular to the major axis direction of at least one of the proximal side cone portion and the distal side cone portion, to the angle θ3, which is the angle formed by the straight line connecting the two inner layer end portions and the straight line connecting the inner layer end portion and the inner layer top portion in the circumferential first direction, that is, the angle θ4 / angle θ3, is greater than the ratio of the angle θ6, which is the angle formed by the straight line connecting the two outer layer end portions and the straight line connecting the outer layer end portion and the outer layer top portion in the circumferential first direction in the cross-section perpendicular to the major axis direction of at least one of the proximal side sleeve portion and the distal side sleeve portion, to the angle θ5, which is the angle formed by the straight line connecting the two inner layer end portions and the straight line connecting the inner layer end portion and the inner layer top portion in the circumferential first direction, that is, the angle θ6 / angle θ5.

13. The balloon for a balloon catheter according to claim 10 or 11, wherein The angle at the inner layer top portion in the triangle formed by connecting the two inner layer end portions and the inner layer top portion in the cross-section perpendicular to the major axis direction of the straight tube portion is greater than the angle at the inner layer top portion in the triangle formed by connecting the two inner layer end portions and the inner layer top portion in the cross-section perpendicular to the major axis direction of at least one of the proximal side cone portion and the distal side cone portion.

14. The balloon for a balloon catheter according to claim 10 or 11, wherein The proportion of the area of the inner layer at the protruding portion in the cross-section perpendicular to the major axis direction of the straight tube portion is less than the proportion of the area of the inner layer at the protruding portion in the cross-section perpendicular to the major axis direction of at least one of the proximal side cone portion and the distal side cone portion.

15. A balloon catheter, wherein The balloon for a balloon catheter according to claim 10 or 11 is provided.

16. A method for manufacturing a balloon catheter for manufacturing the balloon catheter according to claim 15, wherein Comprising: A step of preparing a preform having a radial direction, a circumferential direction, and a major axis direction, and having a lumen extending in the major axis direction; And A step of stretching the preform to manufacture a balloon having a proximal side sleeve portion, a proximal side cone portion, a straight tube portion, a distal side cone portion, and a distal side sleeve portion, and having a protruding portion protruding outward in the radial direction and extending in the major axis direction. The parison has an outer layer and an inner layer made of a material with a Shore D hardness lower than that of the outer layer, and has a protruding region and a non-protruding region outside the protruding region. The protruding region includes a protrusion that protrudes outward in the radial direction and extends in the long axis direction. In a cross-section perpendicular to the long axis direction, the inner layer has a small thickness portion in the non-protruding region and a large thickness portion with a thickness thicker than that of the small thickness portion in the protruding region.

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