Balloon for balloon catheter and balloon catheter

Abstract

To provide a balloon for a balloon catheter in which a protrusion is provided on a surface and which can enhance the flexibility in a longitudinal axis direction, and to provide a balloon catheter equipped with the balloon.SOLUTION: There is provided a balloon for a balloon catheter in which a protrusion 21 extending in a longitudinal axis direction is provided in a straight piping section of the balloon, a specific notch 22X is formed in the protrusion 21, the protrusion 21 is divided into a plurality of protrusive segments 24 by the specific notch 22X, a distal end edge 31 of the protrusive segment 24P adjacent to a proximal side of the specific notch 22X has a convex shape protruding on a distal side in a plane view from an apex 21A side of the protrusion 21, and a proximal end edge 41 of a protrusive segment 24D adjacent to a distal side of the specific notch 22X has a convex shape protruding on a proximal side.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a balloon for a balloon catheter and a balloon catheter equipped with the balloon. [Background technology]

[0002] It is known that stenosis in blood vessels, which are the channels through which blood circulates in the body, can cause various diseases due to stagnation of blood circulation. In particular, stenosis in the coronary arteries that supply blood to the heart can lead to serious diseases such as angina pectoris and myocardial infarction. One method for treating such vascular stenosis is angioplasty (PTA, PTCA, etc.), which uses a balloon catheter to expand the stenosis.

[0003] There are known balloon catheters with ridges on the surface of the balloon (e.g., Patent Documents 1 to 3). When such a balloon catheter is used, the ridges of the balloon can be inserted into the narrowed portion when the balloon is inflated, thereby effectively expanding the narrowed portion. On the other hand, a balloon with ridges tends to have high rigidity at the portion where the ridges are provided, and the flexibility in the longitudinal direction is easily reduced. In response to this, there are known balloon catheters with notches formed in the ridges on the surface of the balloon (e.g., Patent Documents 4 and 5). When such a balloon catheter is used, the flexibility in the longitudinal direction can be ensured even for a balloon with ridges. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 250611 [Patent Document 2] JP 2009-112361 A [Patent Document 3] JP 2013-176507 A [Patent Document 4] International Publication No. 2012 / 099950 [Patent Document 5] International Publication No. 2020 / 255923 Summary of the Invention [Problem to be solved by the invention]

[0005] A balloon having a ridge on its surface and a notch formed in the ridge can exhibit a scoring function due to the ridge, and the notch formed in the ridge can ensure the flexibility of the balloon in the longitudinal direction. However, since blood vessels have bent parts that are greatly bent, it is desirable that a balloon having a ridge can be smoothly inserted even in such bent parts. Therefore, it would be even more desirable if the flexibility of the balloon could be further improved.

[0006] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a balloon for a balloon catheter, which has a balloon surface with ridges that can enhance bending ability in the longitudinal axis direction, and a balloon catheter equipped with the balloon. [Means for solving the problem]

[0007] The balloon for a balloon catheter and the balloon catheter including the balloon of the present invention, which are able to solve the above-mentioned problems, are as follows. [1] A balloon for a balloon catheter having a longitudinal axis direction extending from a proximal side to a distal side and a radial direction perpendicular to the longitudinal axis direction, The balloon has a straight tube portion, a proximal tapered portion located proximally of the straight tube portion, and a distal tapered portion located distally of the straight tube portion, The straight tube portion has a cylindrical balloon body and a protrusion on an outer surface of the balloon body that protrudes radially outward and extends in the longitudinal axis direction, A notch is formed in the protrusion, and the protrusion is divided into a plurality of protrusion segments by the notch, The balloon for a balloon catheter includes a specific notch that satisfies the following requirements. (Requirements) When viewed in a planar view from the top side of the convex stripe, the distal end edge of the convex stripe segment adjacent to the proximal side of the specific notch (hereinafter referred to as the "proximal convex stripe segment") has a convex shape protruding toward the distal side, and the proximal end edge of the convex stripe segment adjacent to the distal side of the specific notch (hereinafter referred to as the "distal convex stripe segment") has a convex shape protruding toward the proximal side. [2] A balloon as described in [1], wherein the distalmost portion of the distal end edge of the proximal ridge segment is on an imaginary line passing through the apex of the ridge and extending in the longitudinal axis direction when viewed in a planar view from the apex side of the ridge, and / or the proximalmost portion of the proximal end edge of the distal ridge segment is on an imaginary line passing through the apex of the ridge and extending in the longitudinal axis direction when viewed in a planar view from the apex side of the ridge. [3] A balloon as described in [1] or [2], wherein the convex shape of the distal end edge of the proximal ridge segment has a curved portion curved toward the distal side, and / or the convex shape of the proximal end edge of the distal ridge segment has a curved portion curved toward the proximal side. [4] The balloon according to any one of [1] to [3], wherein the convex shape of the distal end edge of the proximal ridge segment, in a plan view seen from the apex side of the ridge, has a proximal first straight section located on one side of an imaginary line passing through the apex of the ridge and extending in the longitudinal direction, and a proximal second straight section located on the other side, and the proximal first straight section and the proximal second straight section extend so as to move away from the imaginary line as they move proximally, and / or the convex shape of the proximal end edge of the distal ridge segment, in a plan view seen from the apex side of the ridge, has a distal first straight section located on one side of the imaginary line and a distal second straight section located on the other side, and the distal first straight section and the distal second straight section extend so as to move away from the imaginary line as they move distally. [5] The balloon described in [4], wherein the convex shape of the distal end edge of the proximal ridge segment, in a planar view from the apex side of the ridge, further has a proximal third straight section between the proximal first straight section and the proximal second straight section, the proximal first straight section and the proximal second straight section being located proximal to the proximal third straight section; and / or the convex shape of the proximal end edge of the distal ridge segment, in a planar view from the apex side of the ridge, further has a distal third straight section between the distal first straight section and the distal second straight section, the distal first straight section and the distal second straight section being located distal to the distal third straight section. [6] A balloon as described in [5], wherein the proximal third straight portion and / or the distal third straight portion extend perpendicular to the longitudinal axis direction. [7] A balloon as described in [4], wherein the distal end of the proximal first straight section is connected to the distal end of the proximal second straight section, and / or the proximal end of the distal first straight section is connected to the proximal end of the distal second straight section. [8] A balloon described in any of [1] to [7], wherein in a cross section along the longitudinal axis direction passing through the apex of the ridge, the distal outer edge of the proximal ridge segment extends with an inclination toward the proximal side in a radially outward direction, and / or, in a cross section along the longitudinal axis direction passing through the apex of the ridge, the proximal outer edge of the distal ridge segment extends with an inclination toward the distal side in a radially outward direction. [9] The balloon according to any one of [1] to [8], wherein the ridges are made of resin, metal, or a combination thereof.

[10] A balloon catheter comprising a balloon according to any one of [1] to [9]. Effect of the Invention

[0008] The balloon for a balloon catheter of the present invention has ridges on the outer surface of the straight tube part of the balloon, so that when a balloon catheter equipped with the balloon is used to expand the balloon at a stenosis or the like of a blood vessel, the ridges bite into the stenosis or the like, thereby enabling effective expansion. In addition, notches are formed in the ridges of the balloon, and the above-mentioned specific notches are formed as at least a part of the notches, so that the flexibility of the balloon can be improved. [Brief description of the drawings]

[0009] [Figure 1] 1 illustrates an example of the configuration of a balloon catheter according to an embodiment of the present invention, and is a side view of the balloon catheter. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II of the balloon catheter shown in FIG. 1. [Diagram 3] FIG. 2 is a cross-sectional view of the balloon catheter shown in FIG. 1 along line III-III. [Figure 4] 1 illustrates an example of a perspective view of a balloon provided in a balloon catheter. [Diagram 5] 5 shows a vertical cross-sectional view in the longitudinal axis direction of the straight tube portion of the balloon shown in FIG. 4. [Figure 6] 6 shows a vertical cross-sectional view of the longitudinal axis direction of the ridges of the balloon shown in FIG. 5. [Figure 7] 7 shows an example of the configuration of a particular notch formed in a balloon's ridge and the adjacent ridge segment, where FIG. 7(a) shows an oblique view of the end of the ridge segment, and FIG. 7(b) shows a plan view of the end of the ridge segment as viewed from the top side of the ridge. [Figure 8] FIG. 8 shows an example of the configuration of a particular notch formed in a balloon's ridge and the adjacent ridge segment, where FIG. 8(a) shows an oblique view of the end of the ridge segment, and FIG. 8(b) shows a plan view of the end of the ridge segment as viewed from the top side of the ridge. [Figure 9] 9 shows an example of the configuration of a specific notch formed in a balloon's ridge and the adjacent ridge segment, where FIG. 9(a) shows an oblique view of the end of the ridge segment, and FIG. 9(b) shows a plan view of the end of the ridge segment as viewed from the top side of the ridge. [Figure 10] FIG. 10 shows an example of the configuration of a particular notch formed in a balloon's ridge and the adjacent ridge segment, with FIG. 10(a) showing an oblique view of the end of the ridge segment and FIG. 10(b) showing a plan view of the end of the ridge segment as viewed from the top side of the ridge. [Figure 11] 11 shows an example of the configuration of a particular notch formed in a balloon's ridge and the adjacent ridge segment, where FIG. 11(a) shows an oblique view of the end of the ridge segment, and FIG. 11(b) shows a plan view of the end of the ridge segment as viewed from the top side of the ridge. [Figure 12] 12 shows an example of the configuration of a particular notch formed in a balloon's ridge and the adjacent ridge segment, where FIG. 12(a) shows an oblique view of the end of the ridge segment, and FIG. 12(b) shows a plan view of the end of the ridge segment as viewed from the top side of the ridge. [Figure 13] 13 shows an example of the configuration of a particular notch formed in a balloon's ridge and the adjacent ridge segment, where FIG. 13(a) shows an oblique view of the end of the ridge segment, and FIG. 13(b) shows a plan view of the end of the ridge segment as viewed from the top side of the ridge. [Figure 14] 14 shows an example of the configuration of a particular notch formed in a balloon's ridge and the adjacent ridge segment, where FIG. 14(a) shows an oblique view of the end of the ridge segment, and FIG. 14(b) shows a plan view of the end of the ridge segment as viewed from the top side of the ridge. [Figure 15] 1 shows an example of a cross-sectional view along the longitudinal axis direction of a ridge and a particular notch provided on a balloon. [Figure 16] 13 shows another example of a cross-sectional view along the longitudinal axis direction of a ridge and a particular notch provided on a balloon. [Figure 17] 13 shows another example of a cross-sectional view along the longitudinal axis direction of a ridge and a particular notch provided on a balloon. [Figure 18] 13 shows another example of a cross-sectional view along the longitudinal axis direction of a ridge and a particular notch provided on a balloon. [Figure 19] FIG. 2 illustrates another example of a perspective view of a balloon provided in a balloon catheter. [Figure 20]FIG. 2 illustrates another example of a perspective view of a balloon provided in a balloon catheter. [Figure 21] 13 shows another example of a vertical cross-sectional view of a balloon's ridges in the longitudinal axis direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described in detail below based on the following embodiments, but the present invention is not limited to the following embodiments, and can be modified as appropriate within the scope of the above and below, and all of these are included in the technical scope of the present invention. In addition, hatching and component symbols may be omitted in each drawing for convenience, but in such cases, the specification and other drawings should be referred to. Furthermore, the dimensions of various components in the drawings may differ from the actual dimensions, since priority is given to helping understand the features of the present invention.

[0011] A balloon for a balloon catheter according to an embodiment of the present invention and a configuration example of a balloon catheter equipped with the balloon will be described with reference to the drawings. Fig. 1 to Fig. 4 show a configuration example of a balloon catheter. Fig. 1 shows a side view of a balloon catheter, Fig. 2 shows a II-II cross-sectional view of the balloon catheter shown in Fig. 1, Fig. 3 shows a III-III cross-sectional view of the balloon catheter shown in Fig. 1, and Fig. 4 shows an example of a perspective view of a balloon equipped in a balloon catheter. Fig. 1 shows a configuration example of a rapid exchange type balloon catheter.

[0012] The balloon catheter 1 has a shaft 2 and a balloon 10 provided on the outside of the shaft 2. The balloon catheter 1 has a proximal side and a distal side, and the balloon 10 is provided on the distal part of the shaft 2. The proximal side of the balloon catheter 1 refers to the direction toward the hand of the user (operator) relative to the extension direction of the balloon catheter 1, and the distal side refers to the opposite direction of the proximal side, i.e., the direction toward the treatment target side. The direction from the proximal side to the distal side of the balloon catheter 1 is referred to as the longitudinal axis direction.

[0013] The balloon catheter 1 is configured so that fluid is supplied to the inside of the balloon 10 through the shaft 2, and the expansion and contraction of the balloon 10 can be controlled using an indeflator (a balloon pressurizer / depressurizer). The fluid may be a pressurized fluid pressurized by a pump or the like. Hereinafter, the fluid supplied to the inside of the balloon 10 is referred to as the "balloon expansion fluid."

[0014] The shaft 2 is composed of, for example, an inner shaft 3 and an outer shaft 4. The inner shaft 3 is disposed in the lumen of the outer shaft 4. The inner shaft 3 can function as a passage for a guide wire that guides the advancement of the shaft 2, and when the balloon catheter 1 is used, the guide wire is inserted into the lumen of the inner shaft 3. The space between the inner shaft 3 and the outer shaft 4 can function as a flow path for the balloon inflation fluid.

[0015] In the rapid exchange type balloon catheter 1, a guidewire port 7 is provided midway from the distal to the proximal side of the shaft 2, and the proximal end of the inner shaft 3 is connected to the guidewire port 7 and the distal end of the inner shaft 3 extends to the distal portion of the shaft 2, thereby forming a guidewire insertion passage extending from the guidewire port 7 to the distal portion of the shaft 2.

[0016] The outer shaft 4 may have a proximal outer shaft 4A and a distal outer shaft 4B, and in this case, it is preferable that the inner shaft 3 is disposed in the lumen of the distal outer shaft 4B. The proximal outer shaft 4A and the distal outer shaft 4B may be made of the same material, or may be made of different materials. For example, it is preferable that the proximal outer shaft 4A is made of a resin or a metal, and the distal outer shaft 4B is made of a resin. Note that the outer shaft 4 may not be divided into the proximal outer shaft 4A and the distal outer shaft 4B, but may be made of one member, or the proximal outer shaft 4A and the distal outer shaft 4B may be further made of multiple tube members.

[0017] A hub 5 is preferably provided on the proximal side of the shaft 2. The hub 5 preferably has a fluid injection section 6 that communicates with a flow path for a balloon expansion fluid in the shaft 2. The balloon 10, the shaft 2 (the inner shaft 3, the outer shaft 4), and the hub 5 can be joined together by a conventionally known joining means such as an adhesive or thermal welding.

[0018] Although not shown in the drawings, the balloon catheter may be an over-the-wire type balloon catheter in which the inner shaft extends from the distal to the proximal part of the shaft and a guide wire passage is formed from the distal to the proximal side of the shaft. In this case, it is preferable that the flow path of the balloon inflation fluid and the guide wire passage provided in the shaft extend to the hub, and the hub has a fluid injection part communicating with the flow path of the balloon inflation fluid and a treatment part communicating with the guide wire passage. It is preferable that the hub has a bifurcated structure, with the fluid injection part provided on one side of the bifurcated part and the treatment part provided on the other side.

[0019] It is preferable that the outer surface of the shaft 2 is coated. In the rapid exchange type balloon catheter 1, it is preferable that the outer surface of one or both of the proximal outer shaft 4A and the distal outer shaft 4B is coated, and it is more preferable that the outer surfaces of both the proximal outer shaft 4A and the distal outer shaft 4B are coated. In the over-the-wire type balloon catheter, it is preferable that the outer surface of the outer shaft is appropriately coated.

[0020] The coating can be a hydrophilic coating or a hydrophobic coating depending on the purpose. The outer surface of the shaft 2 can be coated by immersing the shaft 2 in a hydrophilic or hydrophobic coating agent, applying a hydrophilic or hydrophobic coating agent to the outer surface of the shaft 2, or covering the outer surface of the shaft 2 with a hydrophilic or hydrophobic coating agent. The coating agent may contain drugs or additives.

[0021] Examples of hydrophilic coating agents include hydrophilic polymers such as polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyvinylpyrrolidone, and methyl vinyl ether-maleic anhydride copolymers, and hydrophilic coating agents made of any combination of these.

[0022] Examples of hydrophobic coating agents include polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), perfluoroalkoxyalkane (PFA), silicone oil, hydrophobic urethane resin, carbon coat, diamond coat, diamond-like carbon (DLC) coat, ceramic coat, and substances with low surface free energy terminated with alkyl groups or perfluoroalkyl groups.

[0023] A distal tip 8 is preferably provided at the distal end of the balloon catheter 1. The distal tip 8 may be provided as a separate member from the inner shaft 3 on the distal side of the distal end of the inner shaft 3, or the inner shaft 3 may extend distally beyond the distal end of the balloon 10, so that the distal end of the inner shaft 3 functions as the distal tip 8.

[0024] In order to make it possible to confirm the position of the balloon 10 under X-ray fluoroscopy, a radiopaque marker 9 may be disposed on the shaft 2 at a portion where the balloon 10 is located in the longitudinal direction. The radiopaque marker 9 may be disposed, for example, on the inner shaft 3 disposed inside the balloon 10, and is preferably disposed at positions corresponding to both ends of the straight tube portion of the balloon 10, or may be disposed at a position corresponding to the center of the straight tube portion of the balloon 10.

[0025] The balloon 10 has a longitudinal axis direction and a radial direction, and is formed in a cylindrical shape with openings on the proximal and distal sides (see FIG. 4). The radial direction of the balloon 10 means a direction perpendicular to the longitudinal axis direction, extending radially from the center of the balloon 10. The balloon 10 also has a circumferential direction, which is a direction along the outer periphery of the balloon 10 in an expanded state in a vertical cross section of the balloon 10 in the longitudinal axis direction.

[0026] The balloon 10 has a straight pipe section 13, a proximal taper section 12 located proximal to the straight pipe section 13, and a distal taper section 14 located distal to the straight pipe section 13 in the longitudinal direction. The straight pipe section 13 is formed in a substantially cylindrical shape extending in the longitudinal direction, and is formed to have the largest radial length (outer diameter) in the balloon 10. The proximal taper section 12 is located proximal to the straight pipe section 13 and connects to the proximal end of the straight pipe section 13. The proximal taper section 12 is formed so that the outer diameter becomes smaller as it moves away from the straight pipe section 13. The distal taper section 14 is located distal to the straight pipe section 13 and connects to the distal end of the straight pipe section 13. The distal taper section 14 is formed so that the outer diameter becomes smaller as it moves away from the straight pipe section 13. The balloon 10 preferably further has a proximal sleeve portion 11 located proximal to the proximal taper portion 12 and a distal sleeve portion 15 located distal to the distal taper portion 14. The proximal sleeve portion 11 is located proximal to the proximal taper portion 12 and is connected to the proximal end of the proximal sleeve portion 11. The proximal sleeve portion 11 is formed in a substantially cylindrical shape. The distal sleeve portion 15 is located distal to the distal taper portion 14 and is connected to the distal end of the distal sleeve portion 15. The distal sleeve portion 15 is formed in a substantially cylindrical shape.

[0027] By configuring the balloon 10 as described above, when the balloon 10 is expanded at the stenosis, the straight tube portion 13 comes into sufficient contact with the stenosis, making it easier to perform treatment such as dilating the stenosis. In addition, since the balloon 10 has the proximal tapered portion 12 and the distal tapered portion 14, when the balloon 10 is deflated, the outer diameters of the proximal and distal ends of the balloon 10 can be reduced to reduce the step between the shaft 2 and the balloon 10, making it easier to insert the balloon 10 into a body cavity, a forceps channel of an endoscope, or a delivery catheter such as a guiding catheter.

[0028] In the distal portion of the shaft 2, it is preferable that the inner shaft 3 extends distally beyond the distal end of the outer shaft 4, and that the inner shaft 3 extends through the internal space of the balloon 10 from the proximal sleeve portion 11 to the distal sleeve portion 15. It is also preferable that the outer surface of the inner shaft 3 is joined to the internal surface of the distal sleeve portion 15 of the balloon 10, and the outer surface of the outer shaft 4 is joined to the internal surface of the proximal sleeve portion 11 of the balloon 10. By configuring the distal portion of the shaft 2 in this manner, it is possible to supply the balloon inflation fluid to the internal space of the balloon 10 through the space between the inner shaft 3 and the outer shaft 4.

[0029] There is no particular limitation on the size of the balloon 10. The size of the balloon 10 can be appropriately set, for example, in the range of 4 mm to 400 mm for the length in the longitudinal direction of the straight pipe portion 13 and 1 mm to 30 mm for the outer diameter of the straight pipe portion 13.

[0030] The balloon 10 (particularly the balloon body 16) is preferably made of a resin, more preferably a thermoplastic resin. This makes it easy to manufacture the balloon 10 by molding. Examples of the resin that constitutes the balloon 10 include polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer, polyester resins such as polyethylene terephthalate and polyester elastomer, polyurethane resins such as polyurethane and polyurethane elastomer, polyphenylene sulfide resins, polyamide resins such as polyamide and polyamide elastomer, fluorine-based resins, silicone resins, and natural rubbers such as latex rubber. These may be used alone or in combination of two or more. Among them, polyamide resins, polyester resins, and polyurethane resins are preferably used. In particular, elastomer resins are preferably used in terms of thinning and flexibility of the balloon 10. For example, nylon 12, nylon 11, and the like are examples of polyamide resins that are suitable for the balloon 10, and nylon 12 is preferably used because it can be molded relatively easily during blow molding. Moreover, polyamide elastomers such as polyether ester amide elastomers and polyamide ether elastomers are preferably used from the viewpoints of thinning and flexibility of the balloon 10. Among them, polyether ester amide elastomers are preferably used from the viewpoints of high yield strength and good dimensional stability of the balloon 10.

[0031] The balloon 10 has a convex rib 21 on the outer surface of the straight tube portion 13. By providing the convex rib 21 on the outer surface of the straight tube portion 13, the balloon 10 has a scoring function, and when the balloon 10 is expanded at a stenosed portion of a blood vessel, it can bite into the calcified stenosed portion and create a crack in the stenosed portion. Therefore, the stenosed portion can be expanded while suppressing dissection of the vascular intima. In addition, it is possible to increase the pressure resistance of the balloon 10 and suppress overexpansion during pressurization. The balloon 10 can also be used to treat stenosed portions and lesions in body cavities other than blood vessels, but the following description will focus on the application of the balloon 10 to vascular treatment.

[0032] The ridges 21 of the balloon 10 will be described in detail with reference to Figures 5 and 6. Figure 5 shows a vertical cross-section of the straight pipe portion 13 of the balloon 10 in the longitudinal axis direction, and Figure 6 shows an enlarged cross-section of the ridges 21 of the balloon 10. Figure 5 shows a configuration example of the vertical cross-section of the straight pipe portion 13 of the balloon 10 shown in Figure 4 in the longitudinal axis direction, in which the ridges 21 are provided at three locations in the circumferential direction of the straight pipe portion 13.

[0033] The straight pipe section 13 of the balloon 10 has a cylindrical balloon body section 16, and a convex streak 21 is provided on the outer surface of the balloon body section 16. The convex streak 21 is provided so as to protrude radially outward from the outer surface of the balloon body section 16. By providing the convex streak 21, the straight pipe section 13 has a convex streak region 25 and a convex streak non-existent region 26 on the outer surface of the balloon 10. The convex streak region 25 also includes a portion of the convex streak 21 where a notch 22 is formed, as described below. The outer surface of the straight pipe section 13 is preferably formed flat in the convex streak non-existent region 26, and for example, it is preferable that the outer surface of the straight pipe section 13 is not formed in a recess in a part of the convex streak non-existent region 26. This makes it easier to uniformly expand the balloon 10, and makes it easier to achieve the scoring function of the convex streak 21 as desired. The outer surface of the straight pipe section 13 being formed flat in the non-ridge region 26 means that the non-ridge region 26 is formed in a shape obtained by bending a plane into an arch shape, and no irregularities are formed on the plane bent into an arch shape. The irregularities do not include surface roughness that is inevitably formed during manufacturing.

[0034] The ridges 21 have an apex 21A and a base 21B. In the ridges 21, the apex 21A refers to the tip of the ridges 21, i.e., the radially outermost part of the ridges 21, and the base 21B refers to the boundary with the balloon main body 16, i.e., the radially innermost part of the ridges 21.

[0035] The ridges 21 can be made of, for example, a resin. If the ridges 21 are made of a resin, the balloon 10 having the ridges 21 can be manufactured by resin molding, making the manufacturing process easier. In this case, the ridges 21 and the balloon body 16 are preferably made of the same resin, and the ridges 21 and the balloon body 16 are preferably integrally molded. The balloon body 16 may have an inner layer and an outer layer, and in this case, the ridges 21 are preferably made of the same resin as the outer layer of the balloon body 16. This makes it difficult for the ridges 21 to unintentionally fall off the balloon body 16. Alternatively, the ridges 21 and the balloon body 16 may be made of different resins as long as the resins constituting the ridges 21 and the balloon body 16 have a certain degree of compatibility.

[0036] The ridges 21 may be made of metal, or may be made of a combination of metal and resin. In this case, it is preferable that the portion including the apex 21A of the ridges 21 is made of metal. This makes it easier for the ridges 21 to crack or incise the narrowed portion when the balloon 10 is inflated. For example, the entire ridges 21 may be made of metal, or the portion including the base 21B of the ridges 21 may be made of resin, and the portion including the apex 21A of the ridges 21 may be made of metal. Therefore, it is preferable that the ridges 21 are made of resin, metal, or a combination thereof.

[0037] In the straight pipe section 13, the balloon main body 16 is defined as a portion having a cylindrical shape. The straight pipe section 13 is a portion excluding the ridges 21 protruding radially outward, and the balloon main body 16 is considered to have an outer surface formed into a cylindrical shape. Therefore, in a vertical cross section in the longitudinal axis direction of the straight pipe section 13, the outer shape of the balloon main body 16 is formed into a substantially circular shape, which allows the balloon main body 16 and the ridges 21 to be distinguished from each other. The ridge-existing region 25 is composed of the balloon main body 16 and the ridges 21, and the ridge-free region 26 is composed of the balloon main body 16.

[0038] The ridges 21 are provided on the outer surface of the straight pipe portion 13 so as to extend in a ridge-like manner. The ridges 21 extend approximately parallel to the longitudinal axis of the balloon 10. Thus, the ridges 21 have an extension direction approximately parallel to the longitudinal axis of the balloon 10 and a width direction corresponding to the circumferential direction of the balloon 10.

[0039] The ridges 21 are provided at multiple different circumferential positions on the straight tube portion 13 of the balloon 10. That is, the ridges 21 are provided at multiple locations on the balloon 10 in the circumferential direction. In this case, the ridges 21 are preferably arranged at approximately equal intervals on the straight tube portion 13 of the balloon 10 in the circumferential direction. This makes it possible to create cracks at multiple locations on the narrowed portion when the balloon 10 is expanded. The ridges 21 are preferably provided at two or more locations on the circumferential direction of the balloon 10, more preferably three or more locations, and preferably 12 or less locations, more preferably 10 or less locations, and even more preferably 8 or less locations. In this case, the circumferential interval of the ridges 21 is preferably longer than the circumferential length of one ridge 21.

[0040] The multiple ridges 21 are preferably provided at approximately the same position in the longitudinal direction. That is, the proximal ends of the multiple ridges 21 are preferably located at approximately the same position in the longitudinal direction, and the distal ends of the multiple ridges 21 are preferably located at approximately the same position in the longitudinal direction.

[0041] The cross-sectional shape of the convex rib 21 is not particularly limited. For example, the shape of the convex rib 21 in a vertical cross section in the longitudinal axis direction of the straight pipe section 13 may be a polygon such as a triangle or a rectangle, a partial shape of a circle such as a semicircle or a sector, a wedge shape, a convex shape, a spindle shape, an indefinite shape, or the like. The polygon may have clear corner apexes and straight sides, as well as a rounded polygon with rounded corners and at least a part of the sides is curved. Note that the convex rib 21 is preferably formed so that its width gradually decreases toward the apex 21A.

[0042] In a vertical cross section in the longitudinal axis direction of the straight tube portion 13, the height of the ridge 21 is preferably 0.2 times or more the width (maximum width) of the ridge 21. If the ridge 21 is formed in this manner, when the balloon 10 is expanded at the narrowed portion, the ridge 21 is easily inserted into the narrowed portion, and the scoring function of the ridge 21 can be improved. The ridge 21 is preferably formed so that its width is maximum at the base portion 21B, so that the ridge 21 is stably installed on the outer surface of the balloon main body portion 16. The height of the ridge 21 is more preferably 0.4 times or more the width of the ridge 21, and more preferably 0.7 times or more. On the other hand, the height of the ridge 21 is preferably 2.0 times or less the width of the ridge 21, more preferably 1.8 times or less, and even more preferably 1.5 times or less. This makes it easier to ensure the flexibility of the balloon 10 in the portion where the ridge 21 is present.

[0043] In the straight pipe section 13, the thickness of the portion where the ridges 21 are provided, i.e., the thickness of the ridge-presence region 25, is preferably formed to be thicker than the thickness of the portion where the ridges 21 are not provided, i.e., the thickness of the ridge-free region 26. This can improve the scoring function of the ridges 21. The thickness (maximum thickness) of the ridge-presence region 25 is preferably 1.5 times or more, more preferably 2.0 times or more, and even more preferably 2.5 times or more, the thickness (maximum thickness) of the ridge-free region 26. There is no particular limit to the upper limit of the thickness of the ridge-presence region 25, and may be, for example, 30 times or less, 20 times or less, or 10 times or less, the thickness of the ridge-free region 26.

[0044] In the balloon 10, the ridges 21 are preferably provided over a range of 60% or more, more preferably 70% or more, and even more preferably 80% or more in the longitudinal direction of the straight tube section 13. This allows cracks to be formed over a wide range of the narrowed section when the balloon 10 is expanded. The ridges 21 may be provided over a range of 90% or more in the longitudinal direction of the straight tube section 13, or over almost the entire longitudinal direction of the straight tube section 13, and may also be provided on the outer surfaces of the proximal taper section 12 and / or the distal taper section 14. The ridges 21 may also be provided on the outer surfaces of the proximal sleeve section 11 and / or the distal sleeve section 15.

[0045] The balloon 10 may have an inner ridge (not shown) that protrudes radially inward on the inner surface of the balloon 10. The ridge 21 and the inner ridge may be located at the same position in the longitudinal direction or circumferential direction of the balloon 10, and are preferably integrally molded, whereby a portion of the balloon 10 may be formed thick.

[0046] The balloon 10 provided with the ridges 21 tends to have higher rigidity at the portion where the ridges 21 are provided. Therefore, the balloon 10 provided with the ridges 21 is more likely to have lower flexibility in the longitudinal direction than the balloon 10 without the ridges 21. For example, in a shunt formed during hemodialysis, blood vessels are greatly bent at the arteriovenous anastomosis, and when passing a balloon through such a portion, it may be difficult to pass a balloon provided with the ridges through the arteriovenous anastomosis. Alternatively, in a balloon for the lower limbs, the balloon is inserted through the iliac artery during treatment, and blood vessels are greatly bent at the bifurcation where the left and right iliac arteries branch off from the abdominal aorta. Therefore, when the balloon for the lower limbs is provided with the ridges, it may be difficult to pass the balloon from one of the left and right iliac arteries to the other. In particular, since the balloon for the lower limbs is long, there is a high possibility that the balloon will not be able to pass through a portion where the blood vessels are greatly bent. Therefore, as shown in FIG. 4, the balloon 10 has a notch 22 formed in the ridges 21. By forming the notches 22 in the ridges 21, the flexibility of the balloon 10 in the longitudinal direction can be improved.

[0047] It is preferable that the notch 22 is formed in each ridge 21. This can improve the flexibility of the balloon 10 regardless of the direction in which the balloon 10 bends.

[0048] The number of notches 22 formed in each ridge 21 is not particularly limited as long as it is 1 or more, but from the viewpoint of improving the bending property of the balloon 10, the number of notches 22 formed in each ridge 21 is preferably 2 or more, and more preferably 3 or more. On the other hand, from the viewpoint of ensuring the scoring function of the balloon 10, the number of notches 22 formed in each ridge 21 is preferably 20 or less, more preferably 16 or less, even more preferably 12 or less, and even more preferably 8 or less.

[0049] The notch 22 may be formed so that a part of the apex 21A of the ridge 21 extending in the longitudinal direction is cut off. Although Figs. 15 to 18 show cross-sectional views along the longitudinal direction passing through the apex 21A of the ridge 21 of a specific notch described later, as shown in Figs. 15 and 17, the notch 22 may be formed so as to extend from the apex 21A of the ridge 21 to the base 21B, or as shown in Figs. 16 and 18, the notch 22 may be formed so as to extend halfway from the apex 21A of the ridge 21 to the base 21B. In the former case, the depth of the notch 22 is equal to the height of the ridge 21. In the latter case, the depth of the notch 22 is formed shorter than the height of the ridge 21. Figs. 15 to 18 show cross-sectional views of the ridge 21 including the notch 22, cut by a virtual plane passing through the apex 21A of the ridge 21 and formed by the longitudinal direction and the radial direction of the balloon 10.

[0050] The notch 22 has a bottom 22B and a top 22A, where the bottom 22B refers to the radially innermost portion of the notch 22 and the top 22A refers to the radially outermost portion of the notch 22. The top 22A of the notch 22 coincides with the top 21A of the protruding strip 21. The radial length from the top 22A to the bottom 22B of the notch 22 is the depth of the notch 22.

[0051] The convex strip 21 is divided into a plurality of convex strip segments 24 by the notches 22. Specifically, the convex strip 21 is divided into a proximal convex strip segment 24 and a distal convex strip segment 24 with the bottom 22B of the notch 22 as the boundary. Hereinafter, the convex strip segment 24 adjacent to the proximal side of the notch 22 is referred to as the proximal side convex strip segment 24P, and the convex strip segment 24 adjacent to the distal side of the notch 22 is referred to as the distal side convex strip segment 24D.

[0052] As shown in Figures 15 and 16, when the bottom 22B of the notch 22 is formed with a predetermined length in the longitudinal direction, the proximal convex streak segment 24P is formed proximally from the proximal end of the bottom 22B of the notch 22, and the distal convex streak segment 24D is formed distally from the distal end of the bottom 22B of the notch 22. That is, the proximal end of the bottom 22B of the notch 22 is the distal boundary of the proximal convex streak segment 24P, and the distal end of the bottom 22B of the notch 22 is the proximal boundary of the distal convex streak segment 24D. As shown in Figures 15 and 17, when the notch 22 is formed to extend from the apex 21A to the base 21B of the convex streak 21, the notch 22 forms the interrupted portion 23 of the convex streak 21, and the convex streak segments 24 are arranged on the proximal and distal sides of the interrupted portion 23. In this case, the ridge 21 is formed by alternately arranging the ridge segments 24 and the discontinuous portions 23 in the longitudinal direction. The proximal ridge segment 24P and the distal ridge segment 24D adjacent to the notch 22 may be spaced apart in the longitudinal direction as shown in Figures 15 and 16, or may be in contact with each other in the longitudinal direction as shown in Figures 17 and 18.

[0053] The length in the longitudinal direction of the notch 22 is preferably shorter than the length in the longitudinal direction of the ridge segment 24. Specifically, in each ridge 21, the length in the longitudinal direction of the notch 22 (when a plurality of notches 22 are provided, the length in the longitudinal direction of each notch 22) is preferably shorter than the length in the longitudinal direction of any of the ridge segments 24. Also, in each ridge 21, the length in the longitudinal direction of the notch 22 (when a plurality of notches 22 are provided, the length in the longitudinal direction of each notch 22) is preferably 0.5 times or less, more preferably 0.3 times or less, and even more preferably 0.2 times or less, of the average value of the longitudinal lengths of the ridge segments 24. This makes it easier to ensure the scoring function of the ridge 21. In addition, the longitudinal length of the notch 22 means the distance between the apexes of the ridge segments 24 on the proximal and distal sides of the notch 22 in a cross section along the longitudinal direction passing through the apex 21A of the ridge 21, i.e., the distance between the distal end of the apex of the proximal ridge segment 24P and the proximal end of the apex of the distal ridge segment 24D.

[0054] In each ridge 21, the total length of the notches 22 in the longitudinal direction is preferably 20% or less of the longitudinal length of the ridge 21, more preferably 15% or less, and even more preferably 10% or less. This makes it easier to ensure the scoring function of the ridge 21. The longitudinal length of the ridge 21 is determined as follows. Of the multiple ridge segments 24 constituting each ridge 21, the proximal end of the proximal-most ridge segment 24 becomes the proximal end of the ridge 21, the distal end of the distal-most ridge segment 24 becomes the distal end of the ridge 21, and the longitudinal length from the proximal end to the distal end of the ridge 21 becomes the longitudinal length of the ridge 21.

[0055] In each notch 22, the length in the longitudinal direction of the notch 22 is preferably 0.2 times or more, more preferably 0.3 times or more, and even more preferably 0.5 times or more, the depth of the notch 22. This makes it easy to improve the bending property in the longitudinal direction of the straight tube portion 13 of the balloon 10. In each notch 22, the length in the longitudinal direction of the notch 22 is preferably 5 times or less, more preferably 3 times or less, and even more preferably 2 times or less, the depth of the notch 22. This makes it easy to ensure the scoring function of the balloon 10.

[0056] The length of the portion of the bottom 22B of the notch 22 extending parallel to the longitudinal direction is preferably not much longer than the longitudinal length of the notch 22 (the distance between the apexes of the ridge segments 24 on the proximal and distal sides of the notch 22). In each notch 22, the length of the portion of the bottom 22B of the notch 22 extending parallel to the longitudinal direction is preferably 0.5 times or less, more preferably 0.3 times or less, and even more preferably 0.2 times or less, of the longitudinal length of the notch 22. This makes it easier for the balloon 10 to bend smoothly at the notch 22 and makes it easier to ensure the scoring function of the ridge 21. The bottom 22B of the notch 22 does not need to include a portion extending parallel to the longitudinal direction. In addition, as shown in Figures 15 and 17, when the notch 22 is formed to extend from the top 21A of the convex streak 21 to the base 21B, the longitudinal length of the interrupted portion 23 of the convex streak 21 (the longitudinal length of the interrupted portion 23 on the outer surface of the balloon main body portion 16) corresponds to the longitudinal length of the bottom 22B of the notch 22.

[0057] The notch 22 may be formed at any position in the longitudinal direction of the convex rib 21 provided in the straight pipe section 13. For example, as shown in Fig. 4, in the straight pipe section 13, when the convex rib 21 is divided into three equal parts in the longitudinal direction into a proximal section 17, an intermediate section 18, and a distal section 19, the notch 22 may be provided in any of the proximal section 17, the intermediate section 18, and the distal section 19.

[0058] In one embodiment, the notch 22 is preferably provided at least in the distal section 19. By forming the notch 22 in the ridge 21 in this manner, it is possible to improve the flexibility of the distal portion of the balloon 10 (specifically, the portion of the balloon 10 that corresponds to the distal section 19 of the ridge 21 in the longitudinal direction). In this case, it is preferable that the notch 22 is provided in the distal section 19 of each ridge 21 provided in the straight pipe portion 13.

[0059] It is also preferable that the notch 22 is provided in the proximal section 17 of the ridge 21. This can increase the flexibility of the proximal portion of the balloon 10 (specifically, the portion of the balloon 10 that corresponds to the proximal section 17 of the ridge 21 in the longitudinal direction), and can increase the insertability of the balloon 10 through the curved portion when the balloon 10 is pulled back after treatment with the balloon 10 and passed through the curved portion. In this case, it is preferable that the notch 22 is provided in the proximal section 17 of each ridge 21 provided in the straight tube portion 13.

[0060] The proximal section 17, intermediate section 18, and distal section 19 of the ridge 21 are defined as follows. When the length of each ridge 21 in the longitudinal direction from the proximal end to the distal end of the ridge 21 is L, the ridge 21 is divided into three sections with a length of L / 3, and the most proximal section is defined as the proximal section 17, the most distal section is defined as the distal section 19, and the section between the proximal section 17 and the distal section 19 is defined as the intermediate section 18. The longitudinal position of the notch 22 in the ridge 21, i.e., whether the notch 22 is located in the proximal section 17, intermediate section 18, or distal section 19 of the ridge 21, is determined based on the position of the bottom 22B of the notch 22 in a cross section along the longitudinal direction passing through the apex 21A of the ridge 21 (specifically, a cross section along the longitudinal direction and radial direction passing through the apex 21A of the ridge 21). When bottom 22B of notch 22 is formed with a predetermined length in the longitudinal direction, the midpoint of bottom 22B of notch 22 in the longitudinal direction is taken as the longitudinal position of notch 22 in convex strip 21. When bottom 22B of notch 22 is located exactly at the boundary between proximal section 17 and intermediate section 18 or the boundary between intermediate section 18 and distal section 19, it is determined that it exists in both sections but belongs to neither section.

[0061] The notch 22 does not have to be provided in the middle section 18 of the ridge 21. If the ridge 21 is formed in this manner, it becomes easy to impart a high scoring function to the balloon 10 while improving the flexibility of the balloon 10. On the other hand, in order to further improve the flexibility of the balloon 10, the notch 22 may also be provided in the middle section 18 of the ridge 21. For example, since the balloon 10 for the lower limbs has a long length in the longitudinal direction, by providing the notch 22 in the middle section 18 as well, it is possible to ensure flexibility throughout the entire longitudinal direction of the balloon 10, even in a balloon 10 with a long length in the longitudinal direction.

[0062] In the balloon 10, when the ridge 21 is further provided in at least one of the proximal sleeve portion 11, the proximal tapered portion 12, the distal tapered portion 14, and the distal sleeve portion 15, the notch 22 may also be provided in the ridge 21 of the proximal sleeve portion 11, the proximal tapered portion 12, the distal tapered portion 14, or the distal sleeve portion 15. By providing the notch 22 in this manner, the flexibility of the balloon 10 can be improved even in portions other than the straight tube portion 13.

[0063] The convex strip 21 is provided with a specific notch 22X as a part or the whole of the notch 22 described above. The configuration of the end of the convex strip segment 24 adjacent to the specific notch 22X will be described with reference to Figs. 7 to 14. Figs. 7 to 14 show various configuration examples of the end of the convex strip segment 24 adjacent to the specific notch 22X. Figs. 7(a) to 14(a) show a perspective view of the distal end of the proximal convex strip segment 24P seen from the distal side or a perspective view of the proximal end of the distal convex strip segment 24D seen from the proximal side, and Figs. 7(b) to 14(b) show plan views of the distal end of the proximal convex strip segment 24P and the proximal end of the distal convex strip segment 24D seen from the apex 21A side of the convex strip 21. In addition, the end of the ridge segment 24 means the distal end of the proximal ridge segment 24P adjacent to a particular notch 22X and / or the proximal end of the distal ridge segment 24D.

[0064] The protruding strip 21 has a distal end of the proximal side protruding strip segment 24P adjacent to the specific notch 22X and a proximal end of the distal side protruding strip segment 24D formed as follows. That is, in a plan view seen from the apex 21A side of the protruding strip 21, the distal end edge 31 of the proximal side protruding strip segment 24P adjacent to the proximal side of the specific notch 22X has a convex shape protruding to the distal side, and the proximal end edge 41 of the distal side protruding strip segment 24D adjacent to the distal side of the specific notch 22X has a convex shape protruding to the proximal side. By forming the specific notch 22X in this way, the flexibility of the balloon 10 can be improved. Specifically, when the balloon 10 is bent with the specific notch 22X facing inward, when the distal end of the proximal side protruding strip segment 24P adjacent to the specific notch 22X and the proximal end of the distal side protruding strip segment 24D hit each other, the tips of the convex shapes are likely to be displaced from each other. This makes it easier to bend the balloon 10 to a greater extent. Alternatively, when the balloon 10 is bent, if the specific notch 22X is located on the side of the bent portion of the balloon 10 rather than on the inside of the bent balloon 10, the balloon 10 can be bent to a greater extent.

[0065] The distal end edge 31 of the proximal ridge segment 24P means the outer edge of the proximal ridge segment 24P facing the distal side in a plan view of the ridge 21 seen from the apex 21A side. The proximal end edge 41 of the distal ridge segment 24D means the outer edge of the distal ridge segment 24D facing the proximal side in a plan view of the ridge 21 seen from the apex 21A side. The plan view of the ridge 21 seen from the apex 21A side means the plan view of the ridge 21 seen from the radially outward side.

[0066] The distal end edge 31 of the proximal side ridge segment 24P may be formed of a straight line, a curved line, or a combination thereof, as long as it is formed in a convex shape protruding to the distal side. The proximal end edge 41 of the distal side ridge segment 24D may be formed of a straight line, a curved line, or a combination thereof, as long as it is formed in a convex shape protruding to the proximal side. In addition, when the distal end edge 31 of the proximal side ridge segment 24P and the proximal end edge 41 of the distal side ridge segment 24D are formed of straight lines, these edges are formed of two or more straight lines. The convex shape of the distal end edge 31 of the proximal side ridge segment 24P may be the same as or different from the convex shape of the proximal end edge 41 of the distal side ridge segment 24D. Furthermore, the convex shapes of the distal end edges 31 of the multiple proximal side ridge segments 24P may be the same as or different from each other, and the convex shapes of the proximal end edges 41 of the multiple distal side ridge segments 24D may be the same as or different from each other.

[0067] As shown in FIG. 7, FIG. 8 and FIG. 10, the convex shape of the distal end edge 31 of the proximal side convex stripe segment 24P may be configured to have a curved portion 32 curved toward the distal side, and the convex shape of the proximal end edge 41 of the distal side convex stripe segment 24D may be configured to have a curved portion 42 curved toward the proximal side. If the end of the convex stripe segment 24 is formed in this manner, even if the end of the convex stripe segment 24 hits the inner wall of the blood vessel when the balloon 10 is bent, the inner wall of the blood vessel is less likely to be damaged. This makes it possible to make the balloon 10 safer. When the convex shape of the distal end edge 31 of the proximal side convex stripe segment 24P has a curved portion 32, the curved portion 32 curved toward the distal side may be located distal to the line segment connecting both ends of the curved portion 32. When the convex shape of the proximal end edge 41 of the distal convex strip segment 24D has a curved portion 42, the curved portion 42 curved toward the proximal side may be located proximal to the line segment connecting both ends of the curved portion 42.

[0068] When the convex shape of the distal end edge 31 of the proximal side convex strip segment 24P and / or the proximal end edge 41 of the distal side convex strip segment 24D has a curved portion, the entire convex shape may be composed of a curved portion, or only a part of the convex shape may be composed of a curved portion. In the latter case, it is preferable that the convex shape is composed of a curved portion and a straight portion, and it is preferable that the distal end edge 31 of the proximal side convex strip segment 24P and / or the proximal end edge 41 of the distal side convex strip segment 24D are smoothly formed from the curved portion to the straight portion (i.e., in a plan view of the convex strip 21 seen from the top side, the inclination at the connection portion between the curved portion and the straight portion changes continuously). In FIG. 7, the convex shape of the distal end edge 31 of the proximal side convex strip segment 24P is composed only of the curved portion 32, and the convex shape of the proximal end edge 41 of the distal side convex strip segment 24D is composed only of the curved portion 42. In Fig. 8, the convex shape of the distal end edge 31 of the proximal ridge segment 24P is composed of a curved portion 32 and a straight portion 33, and the convex shape of the proximal end edge 41 of the distal ridge segment 24D is composed of a curved portion 42 and a straight portion 43. In Fig. 10, the convex shape of the distal end edge 31 of the proximal ridge segment 24P is composed of a curved portion 32, a proximal first straight portion 34, and a proximal second straight portion 35, and the convex shape of the proximal end edge 41 of the distal ridge segment 24D is composed of a curved portion 42, a distal first straight portion 44, and a distal second straight portion 45.

[0069] As shown in Figs. 9 to 11, the convex shape of the distal end edge 31 of the proximal side convex strip segment 24P may be configured to have a proximal side first straight portion 34 located on one side of an imaginary straight line H passing through the apex 21A of the convex strip 21 and extending in the longitudinal direction, and a proximal side second straight portion 35 located on the other side, and the proximal side first straight portion 34 and the proximal side second straight portion 35 may extend so as to move away from the imaginary straight line H as they move toward the proximal side. Also, the convex shape of the proximal end edge 41 of the distal side convex strip segment 24D may be configured to have a distal side first straight portion 44 located on one side of the imaginary straight line H and a distal side second straight portion 45 located on the other side, and the distal side first straight portion 44 and the distal side second straight portion 45 may extend so as to move away from the imaginary straight line H as they move toward the distal side, when viewed from the apex 21A of the convex strip 21. If the end of the convex strip segment 24 is formed in this manner, the balloon 10 can be bent more greatly when a specific notch 22X is located on the side of the bent portion of the balloon 10 when the balloon 10 is bent.

[0070] When the distal end edge 31 of the proximal convex streak segment 24P and / or the proximal end edge 41 of the distal convex streak segment 24D are formed as described above, the proximal first straight line portion 34 may be directly connected to the proximal second straight line portion 35, the proximal first straight line portion 34 and the proximal second straight line portion 35 may be connected via another straight line portion or curved portion, and the distal first straight line portion 44 may be directly connected to the distal second straight line portion 45, and the distal first straight line portion 44 and the distal second straight line portion 45 may be connected via another straight line portion or curved portion. Figures 9 to 11 show configuration examples of the distal end edge 31 of the proximal convex streak segment 24P and the proximal end edge 41 of the distal convex streak segment 24D formed in this manner, each of which will be described below.

[0071] In Fig. 9, the convex shape of the distal end edge 31 of the proximal ridge segment 24P is configured by connecting the distal end of the proximal first straight portion 34 to the distal end of the proximal second straight portion 35, and the convex shape of the proximal end edge 41 of the distal ridge segment 24D is configured by connecting the proximal end of the distal first straight portion 44 to the proximal end of the distal second straight portion 45. If the end of the ridge segment 24 is formed in this manner, when the balloon 10 is bent with the specific notch 22X on the inside, the distal end of the proximal ridge segment 24P and the proximal end of the distal ridge segment 24D are easily misaligned and come into contact with each other, making it easier to bend the balloon 10 significantly.

[0072] In FIG. 10, the convex shape of the distal end edge 31 of the proximal side convex stripe segment 24P is configured to have a curved portion 32 between the proximal side first straight portion 34 and the proximal side second straight portion 35, and the convex shape of the proximal end edge 41 of the distal side convex stripe segment 24D is configured to have a curved portion 42 between the distal side first straight portion 44 and the distal side second straight portion 45. The curved portion 32 constituting the convex shape of the distal end edge 31 of the proximal side convex stripe segment 24P is curved toward the distal side, and the curved portion 42 constituting the proximal end edge 41 of the distal side convex stripe segment 24D is curved toward the proximal side. If the end of the convex stripe segment 24 is formed in this way, even if the end of the convex stripe segment 24 hits the inner wall of the blood vessel when the balloon 10 is bent, the inner wall of the blood vessel is less likely to be damaged.

[0073] In Fig. 11, the convex shape of the distal end edge 31 of the proximal side convex stripe segment 24P has a proximal side third straight portion 36 between the proximal side first straight portion 34 and the proximal side second straight portion 35, and is configured so that the proximal side first straight portion 34 and the proximal side second straight portion 35 are located proximally of the proximal side third straight portion 36, and the convex shape of the proximal end edge 41 of the distal side convex stripe segment 24D has a distal side third straight portion 46 between the distal side first straight portion 44 and the distal side second straight portion 45, and is configured so that the distal side first straight portion 44 and the distal side second straight portion 45 are located distally of the distal side third straight portion 46. Even if the end of the convex stripe segment 24 is formed in this way, even if the end of the convex stripe segment 24 hits the inner wall of the blood vessel when the balloon 10 is bent, the inner wall of the blood vessel is less likely to be damaged. In this case, it is sufficient that at least a part of the proximal first straight portion 34 and at least a part of the proximal second straight portion 35 are located proximal to the proximal third straight portion 36, and it is sufficient that at least a part of the distal first straight portion 44 and at least a part of the distal second straight portion 45 are located distal to the distal third straight portion 46.

[0074] The proximal third straight portion 36 preferably extends so that the angle it forms with the longitudinal axis direction in a plan view seen from the apex 21A side of the convex rib 21 is larger than the angle it forms with the proximal first straight portion 34 and the longitudinal axis direction and the angle it forms with the proximal second straight portion 35 and the longitudinal axis direction. The distal third straight portion 46 preferably extends so that the angle it forms with the longitudinal axis direction in a plan view seen from the apex 21A side of the convex rib 21 is larger than the angle it forms with the distal first straight portion 44 and the longitudinal axis direction and the angle it forms with the distal second straight portion 45 and the longitudinal axis direction. The angles formed by the proximal first straight portion 34, the proximal second straight portion 35, the distal first straight portion 44, and the distal second straight portion 45 with the longitudinal axis direction are in the range of more than 0° and less than 90°, and the angles formed by the proximal third straight portion 36 and the distal third straight portion 46 with the longitudinal axis direction are in the range of more than 0° and less than 90°. When the angle formed by the proximal third straight portion 36 and the distal third straight portion 46 with the longitudinal axis direction is 90°, the proximal third straight portion 36 and the distal third straight portion 46 extend perpendicular to the longitudinal axis direction. The angle formed by the proximal third straight portion 36 and the distal third straight portion 46 with the longitudinal axis direction is preferably 60° or more and 90° or less, more preferably 75° or more and 90° or less. This makes it difficult for the inner wall of the blood vessel to be damaged when the end of the convex strip segment 24 hits the inner wall of the blood vessel. It is more preferable that the proximal third straight portion 36 and / or the distal third straight portion 46 extend perpendicular to the longitudinal direction, and it is particularly preferable that both the proximal third straight portion 36 and the distal third straight portion 46 extend perpendicular to the longitudinal direction. The angles formed by the proximal first straight portion 34, the proximal second straight portion 35, the distal first straight portion 44, and the distal second straight portion 45 with the longitudinal direction are preferably 20° or more, more preferably 30° or more, and are preferably 70° or less, and more preferably 60° or less.

[0075] The most distal part of the distal end edge 31 of the proximal side convex strip segment 24P is preferably on a virtual straight line H that passes through the apex 21A of the convex strip 21 and extends in the longitudinal direction in a plan view from the apex 21A side of the convex strip 21. The most proximal part of the proximal end edge 41 of the distal side convex strip segment 24D is preferably on a virtual straight line H that passes through the apex 21A of the convex strip 21 and extends in the longitudinal direction in a plan view from the apex 21A side of the convex strip 21. In Figs. 7 to 11, 13 and 14, the distal end edge 31 of the proximal side convex strip segment 24P and the proximal end edge 41 of the distal side convex strip segment 24D are formed as described above. By forming the end of the convex strip segment 24 in this manner, when the balloon 10 is bent, the balloon 10 can be bent significantly regardless of the bending direction of the balloon 10, regardless of whether the specific notch 22X is located inside or on the side of the bent part of the balloon 10.

[0076] On the other hand, the convex shape of the distal end edge 31 of the proximal side ridge segment 24P and the convex shape of the proximal end edge 41 of the distal side ridge segment 24D may be configured as shown in Fig. 12. That is, in a plan view seen from the apex 21A side of the ridge 21, the most distal part of the distal end edge 31 of the proximal side ridge segment 24P may be located on one side of the imaginary line H passing through the apex 21A of the ridge 21 and extending in the longitudinal direction, and the most proximal part of the proximal end edge 41 of the distal side ridge segment 24D may be located on the other side of the imaginary line H passing through the apex 21A of the ridge 21 and extending in the longitudinal direction. In this case, the distalmost portion of the distal end edge 31 of the proximal side ridge segment 24P and the proximalmost portion of the proximal end edge 41 of the distal side ridge segment 24D are positioned offset from each other in the width direction of the ridge 21, making it easier to bend the balloon 10 particularly significantly when the balloon 10 is bent with the specific notch 22X facing inward.

[0077] The outer edge shape at any radial position of the distal end of the proximal ridge segment 24P (i.e., the outer edge shape at the distal end of the proximal ridge segment 24P when the ridge 21 is cut by any plane parallel to the outer surface of the balloon body 16) may be similar or dissimilar to the distal end edge 31. For example, the distal end edge 31 of the proximal ridge segment 24P may be composed of a curved portion, and the outer edge shape at any radial position of the distal end of the proximal ridge segment 24P may be composed of a straight portion. Similarly, the outer edge shape at any radial position of the proximal end of the distal ridge segment 24D may be similar or dissimilar to the proximal end edge 41.

[0078] In a cross section along the longitudinal direction passing through the apex 21A of the ridge 21 (specifically, a cross section of the ridge 21 cut by a virtual plane passing through the apex 21A of the ridge 21 and formed by the longitudinal direction and the radial direction), the distal outer edge 37 of the proximal ridge segment 24P may extend radially outward at an inclination toward the proximal side as shown in Figs. 7 to 12, or may extend radially as shown in Fig. 13. As shown in Fig. 14, the distal outer edge 37 of the proximal ridge segment 24P may have a portion extending radially and a portion extending radially outward at an inclination toward the proximal side. Although not shown in the drawings, the distal outer edge 37 of the proximal ridge segment 24P may have a portion extending radially outward at an inclination toward the distal side.

[0079] In a cross section along the longitudinal axis passing through the apex 21A of the ridge 21, the proximal outer edge 47 of the distal ridge segment 24D may extend radially outward at an inclination toward the distal side as shown in Figures 7 to 12, or may extend radially as shown in Figure 13. As shown in Figure 14, the proximal outer edge 47 of the distal ridge segment 24D may have a portion extending radially and a portion extending radially outward at an inclination toward the distal side. Although not shown in the drawings, the proximal outer edge 47 of the distal ridge segment 24D may have a portion extending radially outward at an inclination toward the proximal side.

[0080] In a cross section along the longitudinal axis direction passing through the apex 21A of the ridge 21, the distal outer edge 37 of the proximal ridge segment 24P preferably extends at an incline toward the proximal side toward the radially outward direction, and the proximal outer edge 47 of the distal ridge segment 24D preferably extends at an incline toward the distal side toward the radially outward direction. Figures 15 to 18 show examples of cross-sectional views along the longitudinal axis direction passing through the apex 21A of the ridge 21 of the distal end portion of the proximal ridge segment 24P and the proximal end portion of the distal ridge segment 24D shown in Figures 7 to 12. In Figures 7 to 12, in a cross section along the longitudinal axis direction passing through the apex 21A of the ridge 21, the distal outer edge 37 of the proximal ridge segment 24P extends at an incline toward the proximal side toward the radially outward direction, and the proximal outer edge 47 of the distal ridge segment 24D extends at an incline toward the distal side toward the radially outward direction. When the specific notch 22X is formed so as to extend from the apex 21A to the base 21B of the ridge 21, the cross-sectional view of FIG. 15 or FIG. 17 is referred to, and when the specific notch 22X is formed so as to extend partway from the apex 21A to the base 21B of the ridge 21, the cross-sectional view of FIG. 16 or FIG. 18 is referred to. If the end of the ridge segment 24 is formed in this manner, it becomes easy to greatly bend the balloon 10 when bending the balloon 10 with the specific notch 22X on the inside. In this case, the shape of the distal end edge 31 of the proximal ridge segment 24P and the proximal end edge 41 of the distal ridge segment 24D as viewed from the apex 21A side of the ridge 21 is determined by the bottom 22B of the specific notch 22X.

[0081] In the straight tube portion 13 of the balloon 10, only some of the notches 22 provided in the ridge 21 may be formed as the specific notches 22X, or all of the notches 22 may be formed as the specific notches 22X. It is preferable that more of the notches 22 provided in the ridge 21 are formed as the specific notches 22X. For example, it is preferable that 1 / 4 or more of the notches 22 provided in the ridge 21 are formed as the specific notches 22X, more preferably 1 / 3 or more are formed as the specific notches 22X, even more preferably 1 / 2 or more are formed as the specific notches 22X, and even more preferably 2 / 3 or more are formed as the specific notches 22X.

[0082] It is preferable that a specific notch 22X is provided in each ridge 21. This allows the balloon 10 to bend easily in any radial direction.

[0083] The specific notch 22X is preferably provided at least in the distal section 19 of the ridge 21. Providing the specific notch 22X in the distal section 19 of the ridge 21 makes it easier to push and insert the balloon 10 into the bent portion of the blood vessel. In this case, the specific notch 22X may be provided in the distal section 19 of the ridge 21 in at least one ridge 21, but preferably the specific notch 22X is provided in the distal section 19 of each ridge 21. In addition, all of the notches 22 provided in the distal section 19 of the ridge 21 may be formed as the specific notch 22X.

[0084] It is also preferable that the specific notch 22X is provided in the proximal section 17 of the ridge 21. By providing the specific notch 22X in the proximal section 17 of the ridge 21, it becomes easier to pull back the balloon 10 and insert it through the bent portion. In this case, the specific notch 22X may be provided in the proximal section 17 of the ridge 21 in at least one ridge 21, but preferably the specific notch 22X is provided in the proximal section 17 of each ridge 21. In addition, all of the notches 22 provided in the proximal section 17 of the ridge 21 may be formed as the specific notch 22X.

[0085] The specific notch 22X may be provided in both the distal section 19 and the proximal section 17 of the ridge 21, and may also be provided in the middle section 18 of the ridge 21. By providing the specific notch 22X in the middle section 18 of the ridge 21, the flexibility of the balloon 10 can be further improved.

[0086] In the balloon 10, when the convex rib 21 is further provided in at least one of the proximal sleeve portion 11, the proximal tapered portion 12, the distal tapered portion 14, and the distal sleeve portion 15, the specific notch 22X may also be provided in the convex rib 21 of the proximal sleeve portion 11, the proximal tapered portion 12, the distal tapered portion 14, or the distal sleeve portion 15. This makes it easier to bend the balloon 10 significantly in portions other than the straight tube portion 13.

[0087] As one embodiment, as shown in Fig. 19, the ridge 21 may be provided with notches 22 such that the number of notches 22 provided in the distal section 19 is greater than the number of notches 22 provided in the intermediate section 18. This can increase the flexibility of the distal portion of the balloon 10, making it easier to push the balloon 10 through the bent portion. Also, by providing a smaller number of notches 22 in the intermediate section 18 of the ridge 21, or by not providing any notches 22, the scoring function of the intermediate section 18 of the ridge 21 can be improved.

[0088] As shown in Fig. 20, the ridge 21 may be provided with notches 22 such that the number of notches 22 in the distal section 19 and the number of notches 22 in the proximal section 17 are greater than the number of notches 22 in the intermediate section 18. This makes it easier to insert the balloon 10 into the bent section whether the balloon 10 is pushed through the bent section or pulled through the bent section. In addition, the scoring function of the ridge 21 in the intermediate section 18 can be improved.

[0089] When multiple notches 22 are provided in the ridge 21, the depths of the multiple notches 22 may be the same or different. As one embodiment, the ridge 21 may be provided with the notches 22 as follows. That is, the ridge 21 may be formed with the notches 22 such that the deepest depth of the notches 22 provided in the distal section 19 is deeper than the deepest depth of the notches 22 provided in the intermediate section 18. This can increase the flexibility of the distal portion of the balloon 10, making it easier to push the balloon 10 through the bent portion.

[0090] The convex strip 21 may have notches 22 formed such that the deepest depth of the notches 22 provided in the distal section 19 and the deepest depth of the notches 22 provided in the proximal section 17 are deeper than the deepest depth of the notches 22 provided in the intermediate section 18. This can increase the flexibility of the distal and proximal sections of the balloon 10, making it easier to insert the balloon 10 into the bent section whether the balloon 10 is pushed through the bent section or pulled through the bent section.

[0091] Conversely, the convex strip 21 may be provided with the notches 22 as follows. That is, the convex strip 21 may be formed with the notches 22 such that the deepest depth of the notches 22 provided in the intermediate section 18 is deeper than the deepest depth of the notches 22 provided in the distal section 19. Alternatively, the convex strip 21 may be formed with the notches 22 such that the deepest depth of the notches 22 provided in the intermediate section 18 is deeper than the deepest depth of the notches 22 provided in the distal section 19 and the deepest depth of the notches 22 provided in the proximal section 17. If the convex strip 21 is provided with the notches 22 in this way, the number of notches 22 provided in the intermediate section 18 can be reduced while the flexibility of the intermediate section 18 can be improved. Therefore, the scoring function of the convex strip 21 can be ensured while the flexibility of the balloon 10 can be easily ensured throughout the longitudinal axis direction.

[0092] The length in the longitudinal direction of the straight tube portion 13 of the balloon 10 may be, for example, 4 mm or more, 10 mm or more, 20 mm or more, or 30 mm or more, but the longer the longitudinal length of the balloon 10 provided with the ridges 21, the more difficult it becomes to insert the balloon 10 through a curved portion. Therefore, in order to more effectively provide the effect of providing the notches 22 in the ridges 21, the length in the longitudinal direction of the straight tube portion 13 of the balloon 10 is preferably 50 mm or more, more preferably 60 mm or more, and even more preferably 80 mm or more.

[0093] As shown in FIG. 21, the ridge 21 may be formed so that the width narrows stepwise toward the apex 21A in a vertical cross section in the longitudinal axis direction of the straight pipe portion 13, and the notch 22 may be formed only in the portion of the apex 21A side of the stepped ridge 21. For example, the ridge 21 may have a first step portion 27 adjacent to the outer surface of the balloon body 16 and a second step portion 28 on the apex 21A side, and the notch 22 may be formed in the second step portion 28 and not formed in the first step portion 27. Alternatively, the deep notch 22 may be formed from the second step portion 28 to the first step portion 27, and the shallow notch 22 may be formed in the second step portion 28 and not formed in the first step portion 27. The first step portion 27 and the second step portion 28 may be made of the same material or different materials. For example, both the first step portion 27 and the second step portion 28 may be made of resin, or the first step portion 27 may be made of metal and the second step portion 28 may be made of resin.

[0094] A drug may be retained on the outer surface of the straight tube portion 13 of the balloon 10. The drug is not particularly limited as long as it is a pharmacologically active substance, and examples of the drug include drugs that are acceptable as medicines, such as gene therapy drugs, non-gene therapy drugs, small molecules, and cells. In particular, when the catheter is used for the purpose of suppressing restenosis of blood vessels after treatment in angioplasty, anti-restenosis drugs such as antiproliferative agents and immunosuppressants can be preferably used as the drug. Examples of such drugs include paclitaxel, sirolimus (rapamycin), everolimus, and zotarolimus. [Explanation of symbols]

[0095] 1: Balloon catheter 2: Shaft 3: Inner shaft 4: outer shaft, 4A: proximal outer shaft, 4B: distal outer shaft 5: Hub 6:Fluid injection part 7: Guidewire port 8: Tip 9: X-ray opaque marker 10: Balloon 11: Proximal sleeve part 12: Proximal taper 13: Straight pipe section 14: Distal taper 15: Distal sleeve part 16: Balloon body 17: Proximal section 18: Intermediate section 19: Distal section 21: Protrusion, 21A: Top, 21B: Base 22: notch, 22A: top, 22B: bottom, 22X: specific notch 23: Interrupted section 24: convex segment, 24P: proximal convex segment, 24D: distal convex segment 25: Convex presence area 26: Convex non-existence area 27: 1st stage part 28:Second stage part 31: Distal edge (of proximal ridge segment) 32: Curvature (at the distal edge of the proximal convex segment) 33: Straight section (at the distal edge of the proximal ridge segment) 34: First straight section on the proximal side 35: Proximal second straight section 36: Third straight section on the proximal side 37: Distal outer edge (of the cross section along the longitudinal axis of the proximal ridge segment) 41: Proximal edge (of distal ridge segment) 42: Curvature (at the proximal edge of the distal convex segment) 43: Straight section (at the proximal edge of the distal convex segment) 44: Distal first straight section 45: Distal second straight section 46: Distal third straight section 47: Proximal outer edge (cross section along the longitudinal axis of the distal ridge segment) H: Virtual line

Claims

1. A balloon for a balloon catheter having a longitudinal axis direction extending from a proximal side to a distal side and a radial direction perpendicular to the longitudinal axis direction, The balloon has a straight tube portion, a proximal tapered portion located proximally of the straight tube portion, and a distal tapered portion located distally of the straight tube portion, The straight tube portion has a cylindrical balloon body and a protrusion on an outer surface of the balloon body that protrudes radially outward and extends in the longitudinal axis direction, A notch is formed in the protrusion, and the protrusion is divided into a plurality of protrusion segments by the notch, The balloon for a balloon catheter includes a specific notch that satisfies the following requirements. (Requirements) In a planar view from the top side of the convex strip, the distal end edge of the convex strip segment adjacent to the proximal side of the specific notch (hereinafter referred to as the "proximal convex strip segment") has a convex shape protruding toward the distal side, and the proximal end edge of the convex strip segment adjacent to the distal side of the specific notch (hereinafter referred to as the "distal convex strip segment") has a convex shape protruding toward the proximal side.

2. The most distal portion of the distal end edge of the proximal ridge segment is on a virtual straight line that passes through the apex of the ridge and extends in the longitudinal axis direction when viewed in a plan view from the apex side of the ridge, and / or The balloon of claim 1, wherein the most proximal portion of the proximal end edge of the distal ridge segment is on an imaginary straight line that passes through the apex of the ridge and extends in the longitudinal axis direction when viewed in a plan view from the apex side of the ridge.

3. the convex shape of the distal edge of the proximal ridge segment has a distally curved curvature; and / or The balloon of claim 1 , wherein the convex shape of the proximal edge of the distal ridge segment has a curved portion that curves toward the proximal side.

4. The convex shape of the distal end edge of the proximal side convex strip segment has, in a plan view seen from the apex side of the convex strip, a proximal side first straight line portion located on one side of an imaginary line passing through the apex of the convex strip and extending in the longitudinal axis direction, and a proximal side second straight line portion located on the other side, and the proximal side first straight line portion and the proximal side second straight line portion extend so as to move away from the imaginary line as they go proximally, and / or 2. The balloon of claim 1, wherein the convex shape of the proximal end edge of the distal ridge segment has, in a planar view from the apex side of the ridge, a distal first straight portion located on one side of the imaginary straight line and a distal second straight portion located on the other side, and the distal first straight portion and the distal second straight portion extend away from the imaginary straight line as they extend distally.

5. The convex shape of the distal end edge of the proximal convex strip segment further has a proximal third straight portion between the proximal first straight portion and the proximal second straight portion in a plan view seen from the top side of the convex strip, and the proximal first straight portion and the proximal second straight portion are located proximally of the proximal third straight portion, and / or 5. The balloon according to claim 4, wherein the convex shape of the proximal end edge of the distal ridge segment further has a distal third straight portion between the distal first straight portion and the distal second straight portion in a plan view from the apex side of the ridge, and the distal first straight portion and the distal second straight portion are located distal to the distal third straight portion.

6. The balloon according to claim 5 , wherein the proximal third straight portion and / or the distal third straight portion extend perpendicular to the longitudinal axis direction.

7. a distal end of the proximal first straight section is connected to a distal end of the proximal second straight section; and / or The balloon of claim 4 , wherein a proximal end of the distal first straight section is connected to a proximal end of the distal second straight section.

8. In a cross section along the longitudinal axis passing through the apex of the ridge, the distal outer edge of the proximal ridge segment extends radially outwardly and proximally at an incline, and / or The balloon of claim 1 , wherein in a cross section along the longitudinal axis passing through the apex of the ridge, the proximal outer edge of the distal ridge segment extends radially outward at an inclination toward the distal side.

9. The balloon according to claim 1 , wherein the ridges are made of resin, metal, or a combination thereof.

10. A balloon catheter comprising the balloon according to any one of claims 1 to 9.

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