Balloon catheters and balloon catheters

Abstract

A balloon for a balloon catheter has a balloon body (16) and a rib (21) protruding radially outward on the outer surface of the balloon body (16), a cut (22) is formed in the rib (21), and a drug layer (41) is provided in the cut (22) of the rib (21).

Description

Technical Field

[0001] The present invention relates to a balloon for a balloon catheter having a drug on its surface and a balloon catheter having the balloon. Background Technology

[0002] It is well known that various diseases arise from narrowing of blood vessels, the pathways through which blood circulates in the body, leading to impaired blood circulation. In particular, narrowing of the coronary arteries, which supply blood to the heart, can result in serious conditions such as angina and myocardial infarction. One method for treating this narrowing of blood vessels is angioplasty (PTA, PTCA, etc.), which uses a balloon catheter to dilate the narrowed area.

[0003] It is known that balloon catheters have raised strips on the surface of the balloon (e.g., Patent Documents 1-5). When such a balloon catheter is used, the raised strips can engage with the narrowed portion during balloon inflation, effectively dilating the narrowed area. On the other hand, in the case of angioplasty, restenosis sometimes occurs at the dilated narrowed portion. To reduce the frequency of such restenosis (restenosis rate), a balloon catheter that retains medication on its surface is also known (e.g., Patent Documents 4-7). Using a balloon catheter that retains medication in this way allows the medication to be transferred to the inner wall of the body cavity, such as the vessel wall, by inflating the balloon at the narrowed or diseased portion of the body cavity, thus inhibiting restenosis and the like.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2009-112361

[0005] Patent Document 2: Japanese Patent Application Publication No. 2017-12678

[0006] Patent Document 3: International Publication No. 2020 / 250611

[0007] Patent Document 4: Japanese Patent Publication No. 2008-539959

[0008] Patent Document 5: Japanese Patent Application Publication No. 2013-176507

[0009] Patent Document 6: Japanese Patent Publication No. 2008-529740

[0010] Patent Document 7: Japanese Patent Application Publication No. 2015-217260

[0011] A balloon catheter holding a drug on its surface can transfer the drug to the inner wall of a body cavity, such as a blood vessel wall, by expanding the balloon at a narrow or diseased portion. In this case, it is desirable for the drug to take effect gradually by penetrating into the inner wall of the body cavity, rather than being supplied to the inner wall of the body cavity all at once. This can, for example, inhibit the formation of aneurysms caused by over-administration of the drug. The present invention has been made in view of the above-mentioned circumstances, and its object is to provide a balloon for a balloon catheter capable of slowly delivering a drug to the inner wall of a body cavity, such as a blood vessel, and a balloon catheter equipped with such a balloon. Summary of the Invention

[0012] The balloon for balloon catheters of the present invention, which can solve the above-mentioned problems, and the balloon catheter having the balloon are described below.

[0013] [1] A balloon for a balloon catheter has a long axis extending from the proximal side to the distal side, a radial direction perpendicular to the long axis, and a circumferential direction, wherein,

[0014] The aforementioned balloon has a main body and a ridge protruding radially outward from the outer surface of the main body, with a cut formed in the ridge.

[0015] A pharmaceutical layer is provided in the cut of the aforementioned protrusion.

[0016] [2] According to the balloon described in [1], among which,

[0017] The balloon has: a straight tube; a proximal cone located closer to the side than the straight tube; and a distal cone located more distal to the side than the straight tube, wherein the drug layer is provided in the incision of the protrusion in the straight tube.

[0018] [3] According to the balloon described in [1] or [2], wherein,

[0019] The aforementioned incision includes a specific incision in which the aforementioned drug layer is provided, satisfying the following requirements.

[0020] (Requirement) The outer surface of the balloon is divided into a region where the ridges are present and a region where the ridges are absent. In a cross-section perpendicular to the long axis direction at the bottom of the specific incision, the average thickness of the drug layer at the specific incision is greater than the average thickness of the drug layer in the region where the ridges are absent.

[0021] [4] According to any one of [1] to [3], the balloon,

[0022] The aforementioned cuts include specific cuts that meet the following requirements.

[0023] (Requirement) In a cross-section passing through the top of the aforementioned ridge and along the extension direction and radial direction of the aforementioned ridge, at least a portion of the outer edge of the proximal side of the aforementioned specific cut is located closer to the position than the imaginary line connecting the top and bottom of the outer edge of the proximal side of the aforementioned specific cut, and / or at least a portion of the outer edge of the distal side of the aforementioned specific cut is located further to the position than the imaginary line connecting the top and bottom of the outer edge of the distal side of the aforementioned specific cut.

[0024] [5] According to any one of [1] to [4], the balloon,

[0025] The aforementioned incision includes a specific incision in which the aforementioned drug layer is provided, satisfying the following requirements.

[0026] (Requirement) In a cross-section passing through the top of the aforementioned protrusion and along the extension direction and radial direction of the aforementioned protrusion, the surface of the aforementioned drug layer disposed at the aforementioned specific cut is recessed radially inward, and the aforementioned drug layer is present at the bottom of the aforementioned specific cut.

[0027] [6] According to any one of [1] to [5], the balloon,

[0028] The aforementioned incision includes a specific incision in which the aforementioned drug layer is provided, satisfying the following requirements.

[0029] (Requirement) In a cross section passing through the top of the aforementioned protrusion and along the extension direction and radial direction of the aforementioned protrusion, the shortest distance from the outer edge of the aforementioned specific cut covered by the aforementioned agent layer to the surface of the aforementioned agent layer is the longest outside the bottom of the aforementioned specific cut.

[0030] [7] According to any one of [1] to [6], the balloon,

[0031] The aforementioned incision includes a specific incision in which the aforementioned drug layer is provided, satisfying the following requirements.

[0032] (Requirement) The proximal and / or distal surfaces of the aforementioned specific cut are formed to be radially recessed inward in a vertical section in the extension direction of the aforementioned convex strip.

[0033] [8] According to any one of [1] to [7], the balloon,

[0034] The aforementioned ridge is divided into multiple ridge segments by the aforementioned cut, the aforementioned cut including a specific cut having the aforementioned agent layer that satisfies the following requirements.

[0035] (Requirement) The distal surface of the protruding strip segment (hereinafter referred to as the "proximal protruding strip segment") adjacent to the proximal side of the aforementioned specific cut has a portion extending radially from the bottom of the aforementioned specific cut toward the top and / or extending toward the distal side in a cross-section passing through the top of the aforementioned protruding strip and along the extension direction and radial direction of the aforementioned protruding strip. The proximal surface of the protruding strip segment (hereinafter referred to as the "distal protruding strip segment") adjacent to the distal side of the aforementioned specific cut has a portion extending radially from the bottom of the aforementioned specific cut toward the top and / or extending toward the proximal side in a cross-section passing through the top of the aforementioned protruding strip and along the extension direction and radial direction of the aforementioned protruding strip.

[0036] [9] According to the balloon described in [8], in which,

[0037] A portion of the distal surface of the aforementioned proximal lateral convex segment contacts a portion of the proximal surface of the aforementioned distal lateral convex segment.

[0038]

[10] According to any one of [1] to [9], the balloon, wherein,

[0039] In a vertical cross-section along the extension direction of the aforementioned protrusion, the protrusion is formed such that its width narrows in a stepped manner toward the top of the protrusion, and has a first stepped portion adjacent to the outer surface of the balloon body and a second stepped portion closer to the top side thereon. The aforementioned cut is formed in the second stepped portion and not in the first stepped portion.

[0040]

[11] According to any one of [1] to

[10] , the balloon, wherein,

[0041] Cracks extending along the bottom of the cut are formed on the surface of the aforementioned agent layer.

[0042]

[12] According to any one of [1] to

[11] , the balloon, wherein,

[0043] The pharmaceutical agent constituting the above-mentioned pharmaceutical layer is crystalline.

[0044]

[13] According to any one of [1] to

[12] , the balloon, wherein,

[0045] The surface free energy of the material constituting the surface of the aforementioned protrusion is different from the surface free energy of the material constituting the outer surface of the aforementioned balloon body.

[0046]

[14] According to any one of [1] to

[12] , the balloon, wherein,

[0047] The surface free energy of the material constituting the surface of the aforementioned protrusion is greater than the surface free energy of the material constituting the outer surface of the aforementioned balloon body.

[0048]

[15] According to any one of [1] to

[14] , the balloon, wherein,

[0049] The aforementioned protrusions may be made of resin, metal, or a combination thereof.

[0050]

[16] According to any one of [1] to

[15] , the balloon, wherein,

[0051] The outer surface of the balloon is divided into a region where the ridges are present and a region where the ridges are not present. In the contracted state of the balloon, the inner surface of the balloon body is turned inward and the region where the ridges are not present is folded back to form a folded blade portion that overlaps the region where the ridges are not present. The folded blade portion is overlapped on the outer surface of the balloon and covers the top of the ridges.

[0052]

[17] According to any one of [1] to

[15] , the balloon, wherein,

[0053] The outer surface of the balloon is divided into a region where the ridges are present and a region where the ridges are not present. In the contracted state of the balloon, the inner surface of the balloon body is turned inward and the region where the ridges are not present is folded back to form a folded blade portion that overlaps the region where the ridges are not present. The folded blade portion is arranged on the outer surface of the balloon in a manner that does not cover the top of the ridges.

[0054]

[18] A balloon catheter, wherein,

[0055] It has a balloon as described in any one of [1] to

[17] .

[0056] The balloon catheter of the present invention has a balloon with raised strips on its outer surface, and a drug layer is disposed at the cut of the raised strips. Therefore, when a balloon catheter equipped with the balloon of the present invention is used to inflate a narrow or diseased portion of a body cavity such as a blood vessel, the raised strips can bite into the narrow or diseased portion and effectively expand it, and a drug layer can be disposed near the portion of the narrow or diseased portion after expansion where the raised strips bite into it. The drug layer disposed in this way is not supplied to the interior of the body cavity wall all at once, but rather the drug gradually permeates into the interior of the body cavity wall through the cut of the raised strips. Therefore, the drug can be delivered to the interior of the body cavity wall in a slow-release manner. Attached Figure Description

[0057] Figure 1 This diagram illustrates an example of the configuration of a balloon catheter according to an embodiment of the present invention, showing a side view of the balloon catheter excluding the drug layer on the surface of the balloon.

[0058] Figure 2 express Figure 1 The balloon catheter shown is in section II-II.

[0059] Figure 3 express Figure 1 The balloon catheter shown is in section III-III.

[0060] Figure 4 express Figure 1 The diagram shows a three-dimensional view of the balloon in the balloon catheter.

[0061] Figure 5 express Figure 4 The image shows a vertical cross-sectional view of the balloon along its long axis.

[0062] Figure 6 express Figure 5 An enlarged cross-sectional view of the convex ridges of the balloon shown.

[0063] Figure 7 This is an example of a rib with a pharmaceutical layer provided in the cut of the rib, and it shows a cross-sectional view of the rib along the extension direction of the rib.

[0064] Figure 8 This is another example of a rib with a pharmaceutical layer provided in the cut of the rib, showing a cross-sectional view of the rib along its extension direction.

[0065] Figure 9 This is another example of a rib with a pharmaceutical layer provided in the cut of the rib, showing a cross-sectional view of the rib along its extension direction.

[0066] Figure 10 This is another example of a rib with a pharmaceutical layer provided in the cut of the rib, showing a cross-sectional view of the rib along its extension direction.

[0067] Figure 11 express Figure 7 The XI-XI sectional view of the cut of the convex strip shown.

[0068] Figure 12 This is an example of a raised rib with a pharmaceutical layer on its side, shown as a vertical cross-sectional view along the long axis of the raised rib.

[0069] Figure 13 Another example of the ridges on a balloon, a three-dimensional view showing the cut of the ridges.

[0070] Figure 14 This is an example of a raised rib with a chemical layer at the cut and cracks formed on the surface of the chemical layer, showing a three-dimensional view of the raised rib.

[0071] Figure 15 Is Figure 14 The example shown is a cutout of a raised strip with a pharmaceutical layer, and is a cross-sectional view of the raised strip along its extension direction.

[0072] Figure 16 This is another example of a rib with a chemical layer provided at the cut and cracks formed on the surface of the chemical layer, showing a cross-sectional view of the rib along its extension direction.

[0073] Figure 17 This is another example of a rib with a chemical layer provided at the cut and cracks formed on the surface of the chemical layer, showing a cross-sectional view of the rib along its extension direction.

[0074] Figure 18 This is another example of a rib with a chemical layer provided at the cut and cracks formed on the surface of the chemical layer, showing a cross-sectional view of the rib along its extension direction.

[0075] Figure 19 Indicates in Figure 15 In the cross-sectional view of the ridge along its extension direction shown, a protective layer is provided on the outer surface of the drug layer at the cut of the ridge.

[0076] Figure 20 This is another example of a rib with a pharmaceutical layer provided in the cut of the rib, showing a cross-sectional view of the rib along its extension direction.

[0077] Figure 21 This is another example of a rib with a pharmaceutical layer provided in the cut of the rib, showing a cross-sectional view of the rib along its extension direction.

[0078] Figure 22 This is another example of a rib with a pharmaceutical layer provided in the cut of the rib, showing a cross-sectional view of the rib along its extension direction.

[0079] Figure 23 Another example of the ridges on a balloon is shown in a three-dimensional view.

[0080] Figure 24 Another example of a rib with a pharmaceutical layer provided in the cut of the rib is shown, and a cross-sectional view of the rib along its extension direction is shown.

[0081] Figure 25 Another example of a rib with a pharmaceutical layer provided in the cut of the rib is shown, and a cross-sectional view of the rib along its extension direction is shown.

[0082] Figure 26 express Figure 24 and Figure 25 The XXVI-XXVI sectional view of the cut of the convex strip shown.

[0083] Figure 27This is another example of a rib with a chemical layer provided at the cut and cracks formed on the surface of the chemical layer, showing a cross-sectional view of the rib along its extension direction.

[0084] Figure 28 express Figure 4 The illustration shows an example of a folded balloon, specifically a vertical cross-sectional view along the long axis of the folded balloon.

[0085] Figure 29 express Figure 4 Another example of the folded state of the balloon is shown, representing a vertical cross-sectional view along the long axis of the folded balloon. Detailed Implementation

[0086] The present invention will now be specifically described based on the following embodiments. However, the present invention is not limited to these embodiments, and it is undoubtedly possible to implement it by appropriate modifications within the scope of the preceding / following descriptions, all of which are included within the technical scope of the present invention. Furthermore, in the various drawings, for convenience, there are instances where shaded lines, component reference numerals, etc., are omitted. In such cases, please refer to the specification and other drawings. Additionally, the dimensions of various components in the drawings are primarily advantageous for understanding the features of the present invention, and therefore may differ from the actual dimensions.

[0087] The configuration examples of a balloon for a balloon catheter and a balloon catheter having the balloon according to embodiments of the present invention will be described with reference to the accompanying drawings. Figures 1-6 An example of the configuration of a balloon catheter, excluding the drug layer of the balloon, is shown. Figure 1 This shows a side view of the balloon catheter. Figure 2 express Figure 1 The image shows a cross-sectional view of the balloon catheter along line II-II. Figure 3 express Figure 1 The image shows a cross-sectional view of the balloon catheter along line III-III. Figure 4 express Figure 1 The diagram shows a three-dimensional representation of the balloon in the balloon catheter. Figure 5 express Figure 4 The image shows a vertical sectional view of the balloon along its long axis. Figure 6 express Figure 5 An enlarged cross-sectional view of the convex ridges of the balloon shown. Figure 1 An example of the configuration of a rapid-exchange balloon catheter is shown.

[0088] The balloon catheter 1 has: an axis 2; and a balloon 10 disposed on the outer side of the axis 2. The balloon catheter 1 has a proximal side and a distal side, and the balloon 10 is disposed at the distal portion of the axis 2. The proximal side of the balloon catheter 1, relative to its extension direction, refers to the direction towards the user's (the person performing the surgery's) hand, while the distal side refers to the opposite direction of the proximal side, i.e., the direction towards the treatment object. Furthermore, the direction from the proximal side to the distal side of the balloon catheter 1 is referred to as the long axis direction.

[0089] The balloon catheter 1 is configured to supply fluid to the interior of the balloon 10 via the shaft 2, and the expansion and contraction of the balloon 10 can be controlled using an inflator (balloon depressurizer). The fluid can also be a pressurized fluid that has been pressurized by a pump or the like. Hereinafter, the fluid supplied to the interior of the balloon 10 will be referred to as the "balloon dilation fluid".

[0090] Shaft 2 is composed of, for example, an inner shaft 3 and an outer shaft 4. The inner shaft 3 is disposed within the cavity of the outer shaft 4. The inner shaft 3 functions as an insertion passage for the guidewire that guides the movement of shaft 2; when using balloon catheter 1, the guidewire is inserted into the cavity of the inner shaft 3. The space between the inner shaft 3 and the outer shaft 4 functions as a flow path for the balloon dilation fluid.

[0091] In the rapid exchange type balloon catheter 1, a guidewire port 7 is provided midway from the distal side of the shaft 2 to the proximal side. 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 part of the shaft 2, thereby forming a guidewire insertion passage extending from the guidewire port 7 to the distal part of the shaft 2.

[0092] The outer shaft 4 may also have a proximal outer shaft 4A and a distal outer shaft 4B. In this case, it is preferable to arrange the inner shaft 3 within the cavity 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 of different materials. For example, it is preferable that the proximal outer shaft 4A is made of resin or metal, and the distal outer shaft 4B is made of resin. Alternatively, the outer shaft 4 may not be divided into a proximal outer shaft 4A and a distal outer shaft 4B, but may be constituted by a single component. The proximal outer shaft 4A and the distal outer shaft 4B may also be constituted by multiple tubular components.

[0093] Preferably, a hub 5 is provided on the proximal side of the shaft 2. The hub 5 preferably has a fluid injection section 6 that communicates with the flow path of the balloon dilation fluid of the shaft 2. The connection between the balloon 10, the shaft 2 (inner shaft 3, outer shaft 4), and the hub 5 can be performed using conventionally known joining methods such as adhesives or heat fusion.

[0094] Furthermore, although not shown in the accompanying drawings, the balloon catheter may also be an integrally exchangeable balloon catheter in which the inner shaft extends from the distal portion to the proximal portion of the shaft and forms a guidewire insertion passage from the distal side to the proximal side of the shaft. In this case, it is preferable that the flow path for the balloon dilation fluid and the guidewire insertion passage located on the shaft extend to the hub portion, which is configured to have: a fluid injection section communicating with the flow path for the balloon dilation fluid; and a treatment section communicating with the guidewire insertion passage. Preferably, the hub portion has a two-branched structure, with the fluid injection section located on one of the two branches and the treatment section located on the other.

[0095] Preferably, the outer surface of the outer shaft 2 is coated. In the rapid exchange type balloon catheter 1, it is preferable to coat one or both of the outer surfaces of the proximal outer shaft 4A and the distal outer shaft 4B, and more preferably to coat both the outer surfaces of the proximal outer shaft 4A and the distal outer shaft 4B. In the integral exchange type balloon catheter, it is preferable to appropriately coat the outer surface of the outer shaft.

[0096] Depending on the purpose, the coating can be either a hydrophilic or hydrophobic coating. 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 also contain pharmaceuticals or additives.

[0097] Examples of hydrophilic coating agents include hydrophilic polymers such as polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyvinylpyrrolidone, and methyl vinyl ether maleic anhydride copolymer, or hydrophilic coating agents made from any combination thereof.

[0098] Examples of hydrophobic coating agents include polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), perfluoroalkoxyalkane (PFA), silicone oil, hydrophobic polyurethane resin, carbon coating, diamond coating, diamond-like carbon (DLC) coating, ceramic coating, and substances with low surface free energy terminated by alkyl or perfluoroalkyl groups.

[0099] Preferably, a tip 8 is provided at the distal end of the balloon catheter 1. The tip 8 can be provided as a separate component from the inner shaft 3 and located on the distal side of the inner shaft 3, or the distal end of the inner shaft 3 can be extended by the inner shaft 3 to the distal side of the balloon 10 so that the distal end of the inner shaft 3 functions as the tip 8.

[0100] In axis 2, in order to confirm the position of the balloon 10 under X-ray fluoroscopy, an X-ray-blocking mark 9 can be provided on the part where the balloon 10 is located in the long axis direction. The X-ray-blocking mark 9 can be provided, for example, on the inner axis 3 inside the balloon 10, preferably at both ends of the straight tube of the balloon 10, or at the center of the straight tube of the balloon 10.

[0101] The balloon 10 has a long axis and a radial direction and is formed as a tube with openings on the proximal and distal sides. The radial direction of the balloon 10 refers to the direction perpendicular to the long axis and extending from the center of the balloon 10 toward the radial direction. The balloon 10 also has a circumferential direction in a vertical section along the long axis as a direction along the outer periphery of the balloon 10 in the inflated state.

[0102] like Figure 4 As shown, the preferred balloon 10 has, along its long axis, a: a straight tube portion 13; a proximal conical portion 12 located closer to the straight tube portion 13 than to the proximal side; and a distal conical portion 14 located distal to the straight tube portion 13. The straight tube portion 13 is formed as a generally cylindrical shape extending along its long axis, with its radial length (outer diameter) being the largest in the balloon 10. The proximal conical portion 12 is located on the proximal side of the straight tube portion 13 and connects to the proximal end of the straight tube portion 13. The outer diameter of the proximal conical portion 12 decreases with distance from the straight tube portion 13. The distal conical portion 14 is located on the distal side of the straight tube portion 13 and connects to the distal end of the straight tube portion 13. The outer diameter of the distal conical portion 14 decreases with distance from the straight tube portion 13. The balloon 10 preferably has a proximal sleeve portion 11 located closer to the proximal cone portion 12 and a distal sleeve portion 15 located more distal to the distal cone portion 14. The proximal sleeve portion 11 is located on the proximal side of the proximal cone portion 12 and is connected to the proximal end of the proximal cone portion 12. The proximal sleeve portion 11 is formed in a generally cylindrical shape. The distal sleeve portion 15 is located on the distal side of the distal cone portion 14 and is connected to the distal end of the distal cone portion 14. The distal sleeve portion 15 is formed in a generally cylindrical shape.

[0103] By constructing the balloon 10 as described above, the straight tube 13 makes full contact with the narrowed portion when the balloon 10 is inflated, facilitating treatment such as dilation of the narrowed portion. Furthermore, by having a proximal conical portion 12 and a distal conical portion 14, the outer diameter of the proximal and distal ends of the balloon 10 can be reduced when the balloon 10 is deflated, thereby reducing the step difference between the shaft 2 and the balloon 10. This allows the balloon 10 to be easily inserted into body cavities, into the forceps channel of an endoscope, or into catheters used for delivery such as guide catheters.

[0104] Preferably, in the distal portion of shaft 2, the inner shaft 3 extends distally beyond the distal end of the outer shaft 4, and the inner shaft 3 extends from the proximal sleeve portion 11 to the distal sleeve portion 15 within the internal space of the balloon 10. Furthermore, preferably, the outer surface of the inner shaft 3 engages with the inner surface of the distal sleeve portion 15 of the balloon 10, and the outer surface of the outer shaft 4 engages with the inner surface of the proximal sleeve portion 11 of the balloon 10. By configuring the distal portion of shaft 2 in this way, balloon dilation fluid can be supplied to the internal space of the balloon 10 through the space between the inner shaft 3 and the outer shaft 4.

[0105] The size of the balloon 10 is not particularly limited. For example, the size of the balloon 10 can be appropriately set within the range of 4 mm to 400 mm in length along the long axis of the straight tube 13 and 1 mm to 30 mm in outer diameter of the straight tube 13.

[0106] Preferably, the balloon 10 (especially the balloon body 16) is made of resin, more preferably of thermoplastic resin. This makes it easier to manufacture the balloon 10 by molding. Examples of resins constituting the balloon 10 include polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer; polyester resins such as polyethylene terephthalate and polyester elastomers; polyurethane resins such as polyurethane and polyurethane elastomers; polyphenylene sulfide resins; polyamide resins such as polyamide elastomers; fluorinated resins; silicone resins; and natural rubbers such as latex rubber. Only one of these can be used, or two or more can be used in combination. Among these, polyamide resins, polyester resins, and polyurethane resins are suitable. In particular, considering the thin-film properties and flexibility of the balloon 10, elastomer resins are preferred. For example, nylon 12 and nylon 11 are suitable materials for the balloon 10 among polyamide resins, and nylon 12 is suitable for blow molding because it is easier to mold. Furthermore, considering the thin-film nature and flexibility of the balloon 10, polyamide elastomers such as polyether ester amide elastomers and polyamide ether elastomers are preferred. Among these, polyether ester amide elastomers are preferred due to their high yield strength and good dimensional stability of the balloon 10.

[0107] A raised strip 21 is provided on the outer surface of the balloon 10. The balloon 10 has a scoring function through the raised strip 21, allowing it to penetrate the calcified stenosis when the balloon 10 is inflated at the narrow portion of the blood vessel, thus creating a crack in the stenosis. Therefore, it can inhibit the dissociation of the vascular intima and dilate the stenosis. Furthermore, it can achieve high pressure resistance of the balloon 10 and inhibit over-inflation during pressure application. In addition, the balloon 10 can also be used to treat stenosis and lesions in body cavities outside the blood vessels, but the following description focuses on the application of the balloon 10 in vascular treatment.

[0108] Reference Figure 5 and Figure 6 The protrusions 21 of the balloon 10 are described in detail. Figure 5 A vertical sectional view along the long axis of the straight tube portion 13 of the balloon 10 is shown. Figure 6 An enlarged cross-sectional view of the protrusion 21 of the balloon 10 is shown. Figure 5 It shows Figure 4 The example shown is a vertical cross-section along the long axis of the straight tube portion 13 of the balloon 10, where the protrusions 21 are located. The protrusions 21 are located at three circumferential positions of the straight tube portion 13.

[0109] The balloon 10 has a balloon body portion 16, and a rib 21 is provided on the outer surface of the balloon body portion 16. The rib 21 is configured to protrude radially outward from the outer surface of the balloon body portion 16. By providing the rib 21, the balloon 10 forms a rib presence region 27 and a rib absence region 28 on the outer surface of the straight tube portion 13. Furthermore, as described later, the rib presence region 27 also includes a portion in which a cut 22 is formed in the rib 21.

[0110] The portion of the balloon 10 excluding the radially outwardly projecting rib 21 forms the balloon body portion 16. Preferably, in a vertical cross-section along the long axis of the balloon 10, the balloon body portion 16 is substantially circular in shape. In the straight tube portion 13, the outer surface of the balloon body portion 16 is preferably cylindrical. The rib-present region 27 is formed by the balloon body portion 16 and the rib 21, while the rib-absent region 28 is formed by the balloon body portion 16.

[0111] Preferably, the outer surface of the straight tube portion 13 is formed flat in the region 28 where the ridge is absent. For example, it is preferable that a portion of the outer surface of the straight tube portion 13 in the region 28 where the ridge is absent is not recessed. This facilitates uniform expansion of the balloon 10 and allows it to function as desired based on the notching function of the ridge 21. Furthermore, the flatness of the outer surface of the straight tube portion 13 in the region 28 where the ridge is absent means that the region 28 is formed into an arched shape, and no unevenness is formed on the arched plane. This unevenness does not include surface roughness that is unavoidably formed during manufacturing. Preferably, the regions 28 where the ridge is absent on the outer surfaces of the proximal cone portion 12 and the distal cone portion 14 of the balloon 10 are also formed flat.

[0112] The ridge 21 has a top 21A and a base 21B. In the ridge 21, the top 21A refers to the front end of the ridge 21, that is, the outermost part located in the radial direction of the ridge 21, and the base 21B refers to the boundary with the balloon body 16, that is, the innermost part located in the radial direction of the ridge 21.

[0113] The protrusion 21 can be made of resin, for example. If the protrusion 21 is made of resin, the balloon 10 having the protrusion 21 can be manufactured by resin molding, making manufacturing easier. In this case, it is preferable that the protrusion 21 and the balloon body 16 are made of the same resin, and preferably that the protrusion 21 and the balloon body 16 are integrally molded. The balloon body 16 may also have an inner layer and an outer layer; in this case, it is preferable that the protrusion 21 is made of the same resin as the outer layer of the balloon body 16. This reduces the likelihood of the protrusion 21 accidentally detaching from the balloon body 16. Alternatively, the protrusion 21 and the balloon body 16 may also be made of different resins, provided that the resin constituting the protrusion 21 and the resin constituting the balloon body 16 have some degree of compatibility.

[0114] The protrusion 21 can be made of metal, or a combination of metal and resin. In this case, it is preferable that the portion including the top 21A of the protrusion 21 is made of metal. This makes it easier to form a crack or cut through the narrow portion via the protrusion 21 when the balloon 10 is inflated. For example, the entire protrusion 21 can be made of metal, or the portion including the base 21B of the protrusion 21 can be made of resin, and the portion including the top 21A of the protrusion 21 can be made of metal. Therefore, the protrusion 21 is preferably made of resin, metal, or a combination thereof.

[0115] The ridge 21 is configured to extend in a ridge-like shape on the outer surface of the balloon 10. The ridge 21 has an extending direction and a width direction perpendicular to it. Preferably, the ridge 21 extends along the long axis of the balloon 10. In this case, the ridge 21 may extend substantially parallel to the long axis or extend obliquely in the long axis direction. The ridge 21 may also extend spirally in the long axis direction of the balloon 10. Furthermore, considering the improvement of the scoring function of the balloon 10 and the ease of manufacturing the balloon 10 with the ridge 21, it is preferable that the ridge 21 extends substantially parallel to the long axis direction. The ridge 21 extending substantially parallel to the long axis direction preferably extends at an angle within ±10° relative to the long axis direction, more preferably at an angle within ±5°. In the balloon 10 shown in the figures, the ridge 21 extends substantially parallel to the long axis direction of the balloon 10, and the extending direction of the ridge 21 is consistent with the long axis direction of the balloon 10.

[0116] Preferably, the protrusion 21 is provided at least in the straight tube portion 13. This allows the protrusion 21 to easily penetrate deeply into the narrow portion of the blood vessel when the balloon 10 is dilated, improving the scoring function based on the protrusion 21. In this case, the protrusion 21 is preferably provided in a range of 60% or more, more preferably 70% or more, and even more preferably 80% or more in the long axis direction of the straight tube portion 13. This allows cracks to be formed over a wide area of ​​the narrow portion when the balloon 10 is dilated. The protrusion 21 can be provided in a range of 90% or more in the long axis direction of the straight tube portion 13, or it can be provided in almost the entire long axis direction of the straight tube portion 13. The protrusion 21 can also be provided on the outer surface of the proximal conical portion 12 and / or the distal conical portion 14, and it can also be provided on the outer surface of the proximal sleeve portion 11 and / or the distal sleeve portion 15.

[0117] The rib 21 can be provided as a single rib or multiple ribs in the vertical section along the long axis of the balloon 10. When only one rib 21 is provided in the balloon 10, only one rib-free region 28 is formed in the balloon 10. When multiple ribs 21 are provided in the balloon 10, multiple rib-free regions 28 are formed in the balloon 10. The number of rib-free regions 28 is equal to the number of ribs 21.

[0118] Preferably, multiple protrusions 21 are provided at different circumferential positions in a vertical cross-section along the long axis of the balloon 10. That is, it is preferable that the protrusions 21 are provided at multiple locations circumferentially for the balloon 10. In this case, it is preferable that the protrusions 21 are arranged at approximately equal intervals circumferentially for the balloon 10. Therefore, when the balloon 10 is inflated, cracks can be formed at multiple locations in the narrow portion. It is preferable that the protrusions 21 are provided at two or more locations circumferentially for the balloon 10, more preferably three or more, and even more preferably twelve or fewer, more preferably ten or fewer, and even more preferably eight or fewer. Furthermore, it is preferable that the circumferential spacing of the protrusions 21 in this case is longer than the circumferential length of a single protrusion 21.

[0119] Preferably, the plurality of protrusions 21 are arranged at approximately the same position in the long axis direction. That is, preferably, the proximal ends of the plurality of protrusions 21 are located at approximately the same position in the long axis direction, and preferably, the distal ends of the plurality of protrusions 21 are located at approximately the same position in the long axis direction.

[0120] The cross-sectional shape of the protrusion 21 is not particularly limited. For example, the shape of the protrusion 21 in the vertical cross-section of the extension direction of the protrusion 21 can include polygons such as triangles and quadrilaterals, partial shapes of circles such as semicircles and sectors, wedges, convex shapes, spindle shapes, irregular shapes, etc. In addition to shapes with clearly defined vertices and straight sides, polygons also include rounded polygons with rounded corners and shapes with at least a portion of the sides being curved. Furthermore, it is preferable that the protrusion 21 is formed such that its width gradually decreases towards the top 21A.

[0121] In a vertical cross-section along the extending direction of the ridge 21, 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 way, when the balloon 10 is expanded in the narrow portion, the ridge 21 easily engages with the narrow portion, improving the scoring function based on the ridge 21. The ridge 21 is preferably formed such that its maximum width is at the base 21B, thereby stably positioning the ridge 21 on the outer surface of the balloon body 16. The height of the ridge 21 is more preferably 0.4 times or more the width of the ridge 21, and even 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 ensures the flexibility of the balloon 10 in the portion where the ridge 21 is present.

[0122] In the balloon 10, it is preferable that the wall thickness of the portion where the protrusion 21 is provided, i.e., the wall thickness of the region 27 where the protrusion 21 exists, is greater than the wall thickness of the portion where the protrusion 21 is not provided, i.e., the wall thickness of the region 28 where the protrusion 21 does not exist. This improves the scoring function based on the protrusion 21. The wall thickness (maximum wall thickness) of the region 27 where the protrusion exists is preferably 1.5 times or more, more preferably 2.0 times or more, and even more preferably 2.5 times or more. The upper limit of the wall thickness of the region 27 where the protrusion exists is not particularly limited; for example, it can be less than 30 times, less than 20 times, or less than 10 times the wall thickness of the region 28 where the protrusion does not exist.

[0123] The balloon 10 may also have an inner rib (not shown) protruding radially inward on the inner surface of the balloon 10. The rib 21 and the inner rib may also be arranged in the same position in the long axis direction and circumferential direction of the balloon 10, preferably they are integrally formed, so that a part of the balloon 10 may also be formed as a thick wall.

[0124] The balloon 10 with the protrusion 21 tends to have increased rigidity in the portion where the protrusion 21 is provided. Therefore, compared to the balloon 10 without the protrusion 21, the long-axis curvature of the balloon 10 with the protrusion 21 is more easily reduced. For example, in the shunt formed during hemodialysis, the blood vessel bends significantly at the arteriovenous anastomosis, but when passing the balloon through such a site, it may be difficult for the balloon with the protrusion to pass through the arteriovenous anastomosis. Or, in a lower limb balloon, when the balloon is inserted into the iliac artery during treatment, the blood vessel bends significantly at the branching points of the left and right iliac arteries from the abdominal aorta. Therefore, when the lower limb balloon has the protrusion, it may be difficult for the balloon to pass from one side of the left and right iliac arteries to the other. In particular, the lower limb balloon is longer, so the possibility that the balloon cannot pass through the significantly tortuous parts of the blood vessel increases. Therefore, as Figure 4As shown, a cut 22 is formed in the protrusion 21 of the balloon 10. By forming a cut 22 in the protrusion 21, the flexibility of the balloon 10 in the long axis direction can be improved.

[0125] The cut 22 only needs to be shaped to remove a portion of the top 21A of the protrusion 21. Figures 7-10 The diagram shows a cross-sectional view of the top 21A of the protrusion 21 through the cut and along the extending direction and radial direction of the protrusion 21, but as... Figure 7 and Figure 9 As shown, the cut 22 can be formed to extend from the top 21A of the protrusion 21 to the base 21B, or it can be formed as follows: Figure 8 and Figure 10 As shown, the slit 22 extends from the top 21A of the ridge 21 to the middle of the base 21B. In the former case, the depth of the slit 22 is the same as the height of the ridge 21. In the latter case, the depth of the slit 22 is formed to be shorter than the height of the ridge 21. Figures 7-10 The diagram shows a cross-sectional view of the protrusion 21, including the cut 22, taken by an imaginary plane formed through the top 21A of the protrusion 21 and by the extending direction of the protrusion 21 and the radial direction of the balloon 10. The cut 22 can be formed by removing a portion of the protrusion 21, or by shaping the protrusion 21 into a shape with the cut 22; the method of formation is not particularly limited.

[0126] The cut 22 has a bottom 22B and a top 22A. In the cut 22, the bottom 22B refers to the innermost portion in the radial direction of the cut 22, and the top 22A refers to the outermost portion in the radial direction of the cut 22. The top 22A of the cut 22 coincides with the top 21A of the protrusion 21. The radial length from the top 22A to the bottom 22B of the cut 22 is called the depth of the cut 22. Figures 7-10 In this design, the bottom 22B of the cut 22 is formed with a length of 0 in the extending direction of the protrusion 21, but the bottom 22B of the cut 22 may also be formed with a predetermined length in the extending direction of the protrusion 21. In this case, the bottom 22B of the cut 22 is formed to extend parallel to the extending direction of the protrusion 21, and the bottom 22B has a predetermined length in the extending direction of the protrusion 21. For example, the bottom 22B of the cut 22 may also be formed with a predetermined length in the extending direction of the protrusion 21, and the cut 22 extends to the middle of the base 21B of the protrusion 21.

[0127] The depth of the incision 22 is preferably 0.3 times or more the height of the ridge 21, more preferably 0.5 times or more, and even more preferably 0.7 times or more. This facilitates improved curvature of the balloon 10 along its long axis and, as described later, allows the incision 22 to retain a greater amount of medication. The upper limit of the depth of the incision 22 is not particularly limited; the depth of the incision 22 can be less than 1.0 times the height of the ridge.

[0128] In a cross-section passing through the top 21A of the protrusion 21 and along the extending direction and radial direction of the protrusion 21, the shape of the outer edge of the cut 22 is not particularly limited. The outer edge of the cut 22 can be as follows: Figure 7 and Figure 8 As shown, it can be formed in a straight line, or as... Figure 9 and Figure 10 The incision 22 is formed in a curved shape. The outer edge 23P on the proximal side of the incision 22 can extend proximally from the bottom 22B towards the top 22A, or it can extend distally, or it can extend radially. The outer edge 23D on the distal side of the incision 22 can extend distally from the bottom 22B towards the top 22A, or it can extend proximally, or it can extend radially. Figures 7-10 In the incision 22, the outer edge 23P on the proximal side extends from the bottom 22B toward the top 22A and towards the proximal side, while the outer edge 23D on the distal side extends from the bottom 22B toward the top 22A and towards the distal side.

[0129] Preferably, the cut 22 is formed on each of the protrusions 21. Thus, the flexibility of the balloon 10 can be improved regardless of the direction of its bending.

[0130] The ridge 21 is divided into multiple ridge segments 24 by the cut 22. Specifically, the bottom 22B of the cut 22 is used as the boundary to divide it into ridge segments 24 closer to the position side and ridge segments 24 farther from the position side. Hereinafter, the ridge segment 24 adjacent to the proximal side of the cut 22 will be referred to as the proximal ridge segment 24P, and the ridge segment 24 adjacent to the distal side of the cut 22 will be referred to as the distal ridge segment 24D. When the bottom 22B of the cut 22 is formed for a predetermined length in the extending direction of the ridge 21, the proximal ridge segment 24P is formed closer to the position side than the proximal end of the bottom 22B of the cut 22, and the distal ridge segment 24D is formed farther from the position side than the distal end of the bottom 22B of the cut 22. That is, the proximal end of the bottom 22B of the incision 22 becomes the distal boundary of the proximal convex segment 24P, and the distal end of the bottom 22B of the incision 22 becomes the proximal boundary of the distal convex segment 24D.

[0131] In each ridge 21, the length between the tops 22A of the cuts 22 (or the length between the tops 22A of each cut 22 in the case of multiple cuts 22) is preferably shorter than the length of the ridge segment 24 in the extending direction. In each ridge 21, the length between the tops 22A of the cuts 22 is preferably 0.5 times or less than the average length of the ridge segment 24 in the extending direction, more preferably 0.3 times or less, and even more preferably 0.2 times or less. This easily ensures the scoring function based on the ridge 21. Furthermore, the extending length of the ridge segment 24 described herein refers to the length of the tops 21A of the ridge segment 24.

[0132] In each of the raised strips 21, the total length between the tops 22A of the cuts 22 is preferably less than 20% of the length of the raised strip 21 in the extending direction, more preferably less than 15%, and even more preferably less than 10%. This easily ensures the scoring function based on the raised strips 21. The length of the raised strip 21 in the extending direction includes the length of the cuts 22A and the raised strip segments 24.

[0133] In each incision 22, the length between the tops 22A of the incision 22 is preferably 0.2 times or more the depth of the incision 22, more preferably 0.3 times or more, and even more preferably 0.5 times or more. This facilitates improved curvature of the straight portion 13 of the balloon 10 along its long axis, and, as described later, allows for better retention of a larger amount of medication in the incision 22. In each incision 22, the length between the tops 22A of the incision 22 is preferably 5 times or less the depth of the incision 22, more preferably 3 times or less, and even more preferably 2 times or less. This facilitates ensuring the scoring function of the balloon 10.

[0134] The distal surface 25 of the proximal convex segment 24P and the proximal surface 26 of the distal convex segment 24D can be planar, curved, or a combination thereof. The shape of the distal surface 25 of the proximal convex segment 24P can be the same as or different from the shape of the proximal surface 26 of the distal convex segment 24D. Furthermore, the shapes of the distal surfaces 25 of multiple proximal convex segments 24P can be the same as or different from each other, and the shapes of the proximal surfaces 26 of multiple distal convex segments 24D can be the same as or different from each other. The distal surface 25 of the proximal convex segment 24P refers to the portion of the proximal convex segment 24P facing the distal side, including the proximal outer edge 23P of the incision 22. The proximal surface 26 of the distal convex segment 24D refers to the portion of the distal convex segment 24D facing the proximal side, including the distal outer edge 23D of the incision 22.

[0135] Preferably, the cut 22 of the protrusion 21 is formed at least in the straight tube portion 13 of the balloon 10. This improves the flexibility of the balloon 10 in the long axis direction. The cut 22 of the protrusion 21 can be provided in any of the three sections of the balloon 10 when the straight tube portion 13 is divided into a proximal section 17, a middle section 18, and a distal section 19 in the long axis direction.

[0136] As one embodiment, it is preferable that the incision 22 is provided in the distal region 19 of the straight tube portion 13. By forming the incision 22 with the protrusion 21 in this way, the flexibility of the distal portion of the balloon 10 (specifically the distal region 19 of the straight tube portion 13) can be improved. In this case, it is preferable to provide the incision 22 in the distal region 19 of each protrusion 21 provided in the straight tube portion 13.

[0137] Preferably, the incision 22 is located in the proximal region 17 of the straight tube portion 13. This improves the tortuosity of the proximal portion of the balloon 10 (specifically, the proximal region 17 of the straight tube portion 13), enhancing the balloon's insertion permeability through bends such as blood vessels after treatment with the balloon 10. In this case, it is preferable to provide the incision 22 in the proximal region 17 of each protrusion 21 of the straight tube portion 13.

[0138] The incision 22 may not be located in the middle section 18 of the straight tube 13. If the ridge 21 is formed in this way, the flexibility of the balloon 10 is improved, and it is easier to give the balloon 10 a high degree of scoring capability. On the other hand, to further improve the flexibility of the balloon 10, the incision 22 may be provided in the middle section 18 of the straight tube 13. For example, the balloon 10 for the lower limbs has a long length along its long axis; therefore, by providing the incision 22 in the middle section 18, the flexibility of the balloon 10 along its long axis can be ensured even in a balloon 10 with a long length along its long axis. Furthermore, as will be described later, the incision 22 can retain a larger amount of medication.

[0139] The number of cuts 22 formed on each protrusion 21 is not particularly limited as long as there is one or more, but from the viewpoint of improving the flexibility of the balloon 10, the number of cuts 22 formed on each protrusion 21 is preferably two or more, more preferably three or more. On the other hand, from the point of ensuring the scoring function of the balloon 10, the number of cuts 22 formed on each protrusion 21 is preferably 20 or less, more preferably 16 or less, further preferably 12 or less, and even more preferably 8 or less.

[0140] like Figures 7-10 As shown, the balloon 10 has a drug layer 41 disposed at the incision 22 of the protrusion 21. By disposing the drug layer 41 in this way, when the balloon 10 is inflated at the narrow part of the blood vessel, the protrusion 21 can bite into the narrow part to effectively dilate the narrow part, and the drug can be disposed on the surface of the blood vessel wall near the part where the protrusion 21 bites in. The drug disposed in this way is not supplied to the interior of the blood vessel wall all at once, but gradually penetrates. Thus, for example, it is possible to inhibit the formation of aneurysms caused by excessive drug administration. In addition, the drug is disposed on the surface of the blood vessel wall near the part where the protrusion 21 bites in, so the drug can easily penetrate into the interior of the blood vessel wall through this ruptured part. Therefore, the drug can be delivered to the interior of the blood vessel wall in a slow-release manner.

[0141] Regarding the drug layer 41 located at the incision 22 of the protrusion 21, when the balloon 10 is inflated, the drug is reliably delivered to the surface of the vessel wall without detaching midway. Normally, the balloon 10 is folded in the region 28 where the protrusion is absent before inflating, and this fold is unfolded during inflating. However, the drug layer 41 located at the incision 22 of the protrusion 21 is less affected by the unfolding action of the fold in the region 28 when the balloon 10 is inflated. Therefore, compared to the case where the drug layer 41 is located in the region 28 where the protrusion is absent or on the side 21S of the protrusion 21, the drug layer 41 located at the incision 22 of the protrusion 21 is less likely to peel off from the surface of the balloon 10 when the balloon 10 is inflated. As a result, the drug is reliably delivered to the surface of the vessel wall when the balloon 10 is inflated.

[0142] When multiple cuts 22 are provided on the protrusion 21, an agent layer 41 may be provided in at least one of the multiple cuts 22. It is preferable to provide an agent layer 41 in more than 1 / 2 of the cuts 22, more preferably in more than 3 / 4 of the cuts 22, and even more preferably in all cuts 22.

[0143] The pharmaceutical agents contained in the pharmaceutical layer 41 can be any pharmacologically active substances, without particular limitations. Examples include gene therapy drugs, non-gene therapy drugs, small molecules, and cells, which are permitted as pharmaceuticals. Especially when the balloon catheter 1 is used to inhibit restenosis of blood vessels after angioplasty, anti-restenosis agents such as antiproliferative agents and immunosuppressants are preferred. Specifically, paclitaxel, sirolimus (rapamycin), everolimus, and zotamolimus can be used. Only one of these agents may be used, or two or more may be used.

[0144] In addition to containing pharmacologically active substances, the pharmaceutical layer 41 may also contain adjuvants to improve the dispersibility, solubility, translocation to the blood vessel wall, and storage stability of the pharmaceutical agent. As adjuvants, stabilizers, binders, disintegrants, moisture-proofing agents, preservatives, and solubilizers are used. Specifically, examples include lactose, sucrose, maltose, dextrin, xylitol, erythritol, mannitol, ethylenediamine, potassium iodide, urea, polysorbate, butylated hydroxytoluene, polyethylene glycol, lipids, sodium metabisulfite, ascorbic acid, tocopherol, benzoic acid, parabens, polyacrylic acid, polylactic acid, polyglycolic acid, hyaluronic acid, chitosan, and gelatin.

[0145] To prevent the drug from dissolving or detaching from the body fluid during delivery of the balloon 10 to the narrow portion, a protective layer may be provided on the outer surface of the drug layer 41. This protective layer can be made of, for example, a hydrophilic component. For instance, when the balloon 10 is delivered into a body cavity containing a large amount of lipid-soluble components, such as a bile duct, if a protective layer made of a hydrophilic component is provided on the outer surface of the drug layer 41, dissolution of the protective layer upon contact with the body fluid is inhibited, and the protective layer can perform its protective function. Examples of hydrophilic components include carboxymethyl cellulose, hydroxypropyl cellulose, methyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, alginate, pectin, gum arabic, gellan gum, guar gum, xanthan gum, carrageenan, gelatin, polyethylene glycol, hyaluronic acid, sodium polyacrylate, and other hydrophilic polymers; salts such as potassium chloride and ammonium acetate; amino acids such as glycine and glutamic acid; sugars such as glucose and fructose; and urea. The protective layer can also be composed of hydrophobic components. For example, when the balloon 10 is delivered into a body cavity containing blood vessels or other bodily fluids with high water content, if a protective layer composed of hydrophobic components is disposed on the outer surface of the drug layer 41, the dissolution of the protective layer is inhibited upon contact with the bodily fluids, and the protective layer can perform the protective function of the drug layer 41. Examples of hydrophobic components include lipid compounds such as lecithin, propylene glycol stearate, cholesterol, and terpenes; hydrocarbon compounds such as petrolatum; hydrophobic (meth)acrylic polymers such as polyethyl acrylate and polymethyl methacrylate; hydrophobic polyester polymers such as polylactic acid and polyglycolic acid; and silicone oil.

[0146] Furthermore, even when the balloon 10 is delivered to a body cavity containing blood vessels or other bodily fluids with high water content, the protective layer is still preferably composed of the aforementioned hydrophilic components, particularly high molecular weight hydrophilic polymers. Using high molecular weight hydrophilic polymers as the protective layer prevents dissolution of the protective layer due to water in the bodily fluids, thus maintaining the protective function of the drug layer 41.

[0147] The pharmaceutical agent constituting the pharmaceutical layer 41 is preferably crystalline, and pharmacologically active substances are particularly preferred to be crystalline. Examples of crystalline pharmacologically active substances include paclitaxel, sirolimus (rapamycin), everolimus, and zotamolimus. Furthermore, adjuvants and protective agents included with the pharmacologically active substances are also preferably crystalline. Examples of crystalline adjuvants or protective agents include salts of sugars, urea, and potassium iodide, ascorbic acid, polylactic acid, and polyglycolic acid. This increases the brittleness of the pharmaceutical layer 41, making it easier to peel off from the outer surface of the balloon 10 when the balloon 10 is inflated. On the other hand, considering the need to improve the protective function of the protective layer, it is preferable that the protective layer is amorphous. Components of the amorphous protective layer include hydrophilic polymers such as hyaluronic acid and sodium poly(meth)acrylate, hydrophobic polyester polymers such as D,L-polylactic acid and lactic acid-glycolic acid copolymers, and lipid compounds such as lecithin.

[0148] The drug layer 41 is preferably disposed at the incision 22 of the protrusion 21 located in the straight tube portion 13 of the balloon 10. In this case, it is preferable that at least a portion of the protrusion 21 is located in the straight tube portion 13, and the incision 22 of the protrusion 21 is located in the straight tube portion 13. The straight tube portion 13 of the balloon 10 becomes the most inflated part of the balloon 10 when it is inflated. Therefore, if the drug layer 41 is disposed at the incision 22 of the protrusion 21 located in the straight tube portion 13 of the balloon 10, the drug layer 41 is strongly pressed against the surface of the blood vessel wall when the balloon 10 is inflated, making it easy to reliably deliver the drug to the surface of the blood vessel wall. In addition, the protrusion 21 disposed in the straight tube portion 13 can penetrate deeper into the blood vessel wall when the balloon 10 is inflated, thus making it easier for the drug to penetrate deep into the interior of the blood vessel wall.

[0149] In the cut 22 of the protrusion 21, preferably, an agent layer 41 is provided at least at the bottom 22B of the cut 22. The agent layer 41 may be configured to fill the entire cut 22 or only fill a portion of the cut 22. For example, the thickness of the agent layer 41 at the bottom 22B of the cut 22 may be more than 0.1 times, more than 0.2 times, more than 0.3 times, or more than 0.5 times the depth of the cut 22.

[0150] In incision 22, preferably, the drug layer 41 extends from the distal surface 25 of the proximal lateral convex segment 24P to the proximal surface 26 of the distal lateral convex segment 24D. By configuring the drug layer 41 in this way, the incision 22 can retain more drug, and the incision 22 can stably hold the drug layer 41. Therefore, a greater amount of drug can be delivered to the surface of the blood vessel wall.

[0151] Preferably, the thickness of the drug layer 41 at the bottom 22B of the incision 22 is greater than the thickness of the drug layer 41 at the top 22A of the incision 22. If the drug layer 41 is formed in this way, when the balloon 10 is inflated at the narrow portion of the blood vessel, the amount of drug supplied to the interior of the blood vessel wall at once is reduced, making it easier to distribute more drug on the surface of the blood vessel wall. Therefore, it is possible to prevent excessive local delivery of drug to the interior of the blood vessel wall.

[0152] The thickness of the agent layer 41 at the bottom 22B of the cut 22 and the thickness of the agent layer 41 at the top 22A of the cut 22 can be determined by measuring the thickness of the agent layer 41 formed in the cut 22 in a cross-section passing through the top 21A of the rib 21 and along the extension direction and radial direction of the rib 21. The thickness of the agent layer 41 at the bottom 22B of the cut 22 refers to the shortest distance from the bottom 22B of the cut 22 to the surface of the agent layer 41, that is, the length of the shortest point 42 from the bottom 22B of the cut 22 to the surface of the agent layer 41, which is equivalent to... Figures 7-10 The length indicated by the middle arrow L1. Furthermore, it is assumed that the agent layer 41 develops cracks on its surface due to the drying state. In this case, the shortest distance to the surface of the agent layer 41 other than the cracked area is taken as the thickness of the agent layer 41 at the bottom 22B of the cut 22 of the ridge 21. Regarding the thickness of the agent layer 41 at the top 22A of the cut 22, when there is no agent layer 41 at the top 22A, the thickness is 0. When there is an agent layer 41 at the top 22A, it refers to the shortest thickness of the agent layer 41 at the top 22A, that is, the shortest distance from the top 22A to the surface of the agent layer 41. When the bottom 22B of the cut 22 is formed at a predetermined length in the extending direction of the ridge 21, the thickness of the agent layer 41 at the point where the shortest distance from the bottom 22B to the surface of the agent layer 41 is shortest is taken as the thickness of the agent layer 41 at the bottom 22B of the cut 22.

[0153] Preferably, the drug layer 41 is formed thicker in the incision 22, for example, preferably the drug layer 41 is formed to be thicker than the region 28 where the ridges on the outer surface of the balloon 10 do not exist. Figure 11 It shows Figure 7 The XI-XI cross-sectional view of the cut 22 of the convex strip 21 shown (where only the cross-sectional portion of the drug layer 41 is shown), as Figure 11 As shown, the cut 22 is preferably formed such that the drug layer 41 is thicker than the region 28 where the ridge is not present, and preferably the drug layer 41 is formed in at least one cut 22. For example, the cut 22 preferably includes a specific cut 22 provided with a drug layer 41 that satisfies requirement A below.

[0154] (Requirement A) The outer surface of the balloon 10 is divided into a region 27 where the ridges are present and a region 28 where the ridges are absent. In a cross section perpendicular to the long axis direction through the bottom 22B of a specific incision 22, the average thickness of the drug layer 41 at the specific incision 22 is thicker than the average thickness of the drug layer 41 at the region 28 where the ridges are absent.

[0155] In the specific incision 22 where the drug layer 41 satisfies condition A above, more drug can be retained. By retaining the drug in this way, when the balloon 10 is inflated, a greater amount of drug can be disposed near the portion of the vessel wall surface where the protrusion 21 bites in and tears. As a result, a greater amount of drug can be delivered slowly into the interior of the vessel wall. The average thickness of the drug layer 41 at the specific incision 22 is preferably, for example, at least 1.2 times the average thickness of the drug layer 41 in the region 28 where the protrusion is not present, more preferably at least 1.3 times, and even more preferably at least 1.5 times. The upper limit of the ratio of the average thickness of the drug layer 41 at the specific incision 22 to the average thickness of the drug layer 41 in the region 28 where the protrusion is not present is not particularly limited, and the average thickness of the drug layer 41 in the region 28 where the protrusion is not present may also be 0. Furthermore, it is preferable to also provide an agent layer 41 in the region 28 where the ridge is not present. Therefore, the average thickness of the agent layer 41 at the specific cut 22 is preferably less than 30 times the average thickness of the agent layer 41 in the region 28 where the ridge is not present, more preferably less than 20 times, and even more preferably less than 10 times.

[0156] The average thickness of the drug layer 41 at the specific incision 22 and the average thickness of the drug layer 41 in the region 28 where the protrusion is absent, as described above, can be determined, for example, as follows: The balloon 10 is cut perpendicular to its long axis at a position passing through the bottom 22B of the specific incision 22. While keeping the balloon body approximately circular, the area of ​​the drug layer 41 at the specific incision 22 and the circumferential length of the specific incision 22, as well as the area of ​​the drug layer 41 in the region 28 where the protrusion is absent and the circumferential length of the region 28 where the protrusion is absent, are measured. The average thickness of each drug layer 41 can be determined based on these measured areas and circumferential lengths. The circumferential length of the specific incision 22 refers to the circumferential length at the bottom 22B of the specific incision 22. The area of ​​each drug layer 41 can be easily determined by cutting the balloon 10 perpendicular to its long axis, taking a photograph of the cut section, and performing image processing.

[0157] Alternatively, the drug layer 41 may not be provided in the region 28 where the protrusions are absent on the outer surface of the balloon 10. Furthermore, considering the ability to deliver a larger amount of drug to the narrow portion of the blood vessel through the balloon 10, it is preferable to also provide the drug layer 41 in the region 28 where the protrusions are absent.

[0158] The agent layer 41 may also be disposed on the side 21S of the protrusion 21. Figure 12 The diagram shows an example of a protruding rib 21 with a drug layer 41 provided on its side surface 21S, and a vertical cross-sectional view of the protruding rib 21 along its long axis is shown. The side surface 21S of the protruding rib 21 refers to the side surface of the protruding rib 21 in its width direction. In this case, preferably, the thickness of the drug layer 41 at the base 21B of the protruding rib 21 is thicker than the thickness of the drug layer 41 at the top 21A of the protruding rib 21 on its side surface 21S. This reduces the amount delivered to the interior of the blood vessel wall at once when the balloon 10 is expanded at the narrow portion of the blood vessel. Furthermore, the protruding rib 21 easily engages with the narrow portion, allowing for effective expansion of the narrow portion by the balloon 10. Alternatively, the drug layer 41 may not be provided on the side surface 21S of the protruding rib 21. The preferred embodiment of the agent layer 41 is that it is not provided on the side 21S of the protrusion 21, or that the agent layer 41 is provided in such a way that the thickness of the agent layer 41 at the base 21B of the protrusion 21 is greater than the thickness of the agent layer 41 at the top 21A of the protrusion 21, is in a range of 60% or more in the extending direction of the protrusion 21, more preferably 70% or more, even more preferably 80% or more, and even more preferably 90% or more.

[0159] The thickness of the drug layer 41 at the base 21B and top 21A of the side surface 21S of the protrusion 21 can be determined by measuring the thickness of the drug layer 41 formed on the side surface 21S of the protrusion 21 in a vertical section along the long axis of the balloon 10. The thickness of the drug layer 41 at the base 21B of the side surface 21S of the protrusion 21 refers to the shortest distance from the base 21B to the surface of the drug layer 41 on the side surface 21S of the protrusion 21. In the event of a crack in the drug layer 41, the shortest distance to the surface of the drug layer 41, excluding the cracked area, is taken as the thickness of the drug layer 41 at the base 21B of the side surface 21S of the protrusion 21. Regarding the thickness of the agent layer 41 at the top 21A of the side 21S of the protrusion 21, when there is no agent layer 41 at the top 21A, the thickness is 0. When there is an agent layer 41 at the top 21A, it refers to the shortest thickness of the agent layer 41 at the top 21A, that is, the shortest distance from the top 21A to the surface of the agent layer 41.

[0160] like Figure 9 and Figure 10 As shown, the outer edge 23P on the proximal side and / or the outer edge 23D on the distal side of the preferred cut 22 are preferably formed in a recessed shape in a cross-section passing through the top 21A of the rib 21 and along the extension direction and radial direction of the rib 21, and preferably at least one cut 22 is formed in this way. Therefore, the preferred cut 22 includes a specific cut 22 that satisfies requirement B below.

[0161] (Requirement B) In a cross section passing through the top 21A of the protrusion 21 and along the extension direction and radial direction of the protrusion 21, at least a portion of the outer edge 23P of the proximal side of the specific cut 22 is located closer to the proximal side than the imaginary line connecting the top 22A and bottom 22B of the proximal side of the specific cut 22, and / or at least a portion of the outer edge 23D of the distal side of the specific cut 22 is located further to the distal side than the imaginary line connecting the top 22A and bottom 22B of the distal side of the specific cut 22.

[0162] If the cut 22 is formed in a manner that satisfies requirement B above, a greater amount of drug can be stably retained in the cut 22. More preferably, the outer edge 23P on the proximal side of the specific cut 22 is located closer to the proximal side than the imaginary line connecting the top 22A and bottom 22B of the outer edge 23P, and the outer edge 23D on the distal side of the specific cut 22 is located more distal to the proximal side than the imaginary line connecting the top 22A and bottom 22B of the outer edge 23D. For example, it is preferable that the specific cut 22 is formed with a U-shaped outer edge shape in a cross-section passing through the top 21A of the rib 21 and along the extension direction and radial direction of the rib 21.

[0163] like Figures 7-10 As shown, in the cut 22, the surface of the drug layer 41 may also be formed to be radially recessed in a cross-section passing through the top 21A of the protrusion 21 and along the extension direction and radial direction of the protrusion 21. In this case, it is sufficient to form the drug layer 41 in this way in at least one cut 22. For example, the cut 22 may also include a specific cut 22 provided with a drug layer 41 that satisfies the following requirement C.

[0164] (Requirement C) In a cross section passing through the top 21A of the protrusion 21 and along the extension direction and radial direction of the protrusion 21, the surface of the agent layer 41 provided in the specific cut 22 is recessed radially inward, and the agent layer 41 is present at the bottom 22B of the specific cut 22.

[0165] If the drug layer 41 is provided in a manner that satisfies requirement C above, the drug layer 41 can be stably maintained in the specific cut 22. Therefore, the drug layer 41 is less likely to detach from the specific cut 22. When the drug layer 41 is provided in a manner that satisfies requirement C above, the thickness of the drug layer 41 at the bottom 22B of the specific cut 22 is not particularly limited, for example, it can be less than 0.5 times, less than 0.3 times, or less than 0.2 times the depth of the specific cut 22.

[0166] The incision 22 may also include a specific incision 22 having a drug layer 41 that satisfies the following requirement D.

[0167] (Requirement D) In ​​a cross section passing through the top 21A of the protrusion 21 and along the extension direction and radial direction of the protrusion 21, the shortest distance from the outer edge of the specific cut 22 covered by the agent layer 41 to the surface of the agent layer 41 is the longest outside the bottom 22B of the specific cut 22.

[0168] Figure 10 The diagram shows a configuration example in which the drug layer 41 is provided in a manner that satisfies the aforementioned requirement D. If the drug layer 41 is formed in this way, it can be stably maintained at the specific incision 22, and even if the balloon 10 bends in the long axis direction, the drug layer 41 is not easily detached from the specific incision 22. In this case, in a cross-section passing through the top 21A of the protrusion 21 and along the extension direction and radial direction of the protrusion 21, the drug layer 41 is preferably present at the bottom 22B of the specific incision 22, and preferably the thickness of the drug layer 41 at the bottom 22B of the specific incision 22 is smaller than the thickness of the drug layer 41 at its proximal and distal sides. For example, the thickness of the thickest portion of the drug layer 41 at the specific incision 22 is preferably 1.1 times or more, more preferably 1.2 times or more, further preferably 1.3 times or more, and also preferably 5.0 times or less, more preferably 4.0 times or less, and further preferably 3.0 times or less. Thus, the drug layer 41 can be formed with a suitable thickness within the width of a specific incision 22.

[0169] Cutout 22 may also include a specific cutout 22 that satisfies the following requirement E.

[0170] (Requirement E) The proximal and / or distal surfaces of the specific cut 22 are formed to be radially recessed inward in a vertical section in the extension direction of the rib 21.

[0171] Figure 13 An example is shown in the diagram, illustrating a perspective view of the proximal and distal surfaces of the notch 22 formed in a manner that satisfies the aforementioned requirement E. Furthermore, in Figure 13 In the diagram, the drug layer 41 is omitted. If the incision 22 is formed in a manner that satisfies the aforementioned requirement E, a greater amount of drug can be stably retained in the incision 22. The proximal surface of a particular incision 22 corresponds to the distal surface 25 of the proximal lateral convex segment 24P, and the distal surface of a particular incision 22 corresponds to the proximal surface 26 of the distal lateral convex segment 24D. Figure 13 In this context, the cut 22 can also be viewed as having its proximal and distal surfaces recessed in a cross-section along the extension direction and circumferential direction of the convex strip 21. Specifically, at least a portion of the proximal surface of the cut 22 is recessed towards the proximal side, and at least a portion of the distal surface of the cut 22 is recessed towards the distal side. A specific cut 22 can also be formed to satisfy both requirements B and E mentioned above.

[0172] like Figures 14-18 As shown, preferably, a crack 43 extending along the bottom 22B of the cut 22 of the protrusion 21 is formed on the surface of the agent layer 41. Figures 14-18 An example of a structure is shown in which a protrusion 21 with a crack 43 is formed in the agent layer 41 provided in the cut 22. Figure 14 A perspective view is shown of a raised strip 21 with cracks 43 formed in the agent layer 41 at the cut 22. Figures 15-18 It shows in Figures 7-10 The example shown is where the agent layer 41 of the cut 22 has a crack 43. Figures 15-18 A cross-sectional view of the protrusion 21 is shown, passing through the top 21A of the protrusion 21 and along the extension direction of the protrusion 21 and the radial direction of the balloon 10. By forming a crack 43 on the surface of the drug layer 41 provided in the incision 22 of the protrusion 21, if the drug layer 41 comes into contact with the inner surface of the blood vessel wall when the balloon 10 is expanded in the stenosis, the drug layer 41 provided in the incision 22 of the protrusion 21 can easily peel off from the surface of the balloon 10 with the crack 43 as the starting point, and the drug layer 41 can easily transfer from the surface of the balloon 10 to the blood vessel wall side.

[0173] Preferably, the crack 43 is formed such that, when viewed from the outside, the balloon 10 extends along the bottom 22B of the cut 22 on the surface of the drug layer 41, i.e., along the extension direction of the bottom 22B (see reference). Figure 14 The crack 43 can be formed to extend parallel to the extension direction of the bottom 22B, or at least a portion of the crack 43 can extend obliquely relative to the extension direction of the bottom 22B. The crack 43 can be formed entirely to extend along the extension direction of the bottom 22B of the cut 22. The crack 43 can be formed to extend continuously along the bottom 22B, or it can be formed to extend discontinuously. Furthermore, at least a portion of a plurality of cracks 43 extending along the bottom 22B can also be formed side-by-side in the extension direction of the ridge 21.

[0174] like Figures 15-18 As shown, preferably in a cross-section along the extension direction and radial direction of the rib 21, the crack 43 forms at or near the shortest point 42 on the surface of the agent layer 41, starting from the bottom 22B of the cut 22. Specifically, preferably in a vertical cross-section along the extension direction and radial direction of the rib 21, a straight line connecting the shortest point 42 on the surface of the agent layer 41 is drawn from the bottom 22B of the cut 22 of the rib 21. When the length of this straight line from the bottom 22B to the shortest point 42 is set as R, in a cross-section along the extension direction and radial direction of the rib 21, the crack 43 on the surface of the agent layer 41 is located inside an imaginary circle 44 with a radius of 1.5R centered at the bottom 22B. More preferably, in a cross-section along the extension direction and radial direction of the rib 21, the crack 43 is entirely contained within an imaginary circle 44 with a radius of 1.5R centered at the bottom 22B. Figures 15-18In the diagram, a portion of an imaginary circle 44 with a radius of 1.5R centered at the bottom 22B is shown using a single-dotted line. The radius of the imaginary circle 44 is more preferably 1.3R.

[0175] In the cross-section along the extension direction and radial direction of the ridge 21, the crack 43 can be formed to extend from the surface of the drug layer 41 to the outer surface of the balloon 10, or it can be formed to extend from the surface of the drug layer 41 to the interior of the drug layer 41.

[0176] When there are multiple cuts 22 in the protrusion 21, it is sufficient that a crack 43 is formed in the agent layer 41 along at least one bottom 22B of the multiple cuts 22. When there are multiple protrusions 21, it is sufficient that a crack 43 is formed in the agent layer 41 along at least one bottom 22B of the cuts 22 in each protrusion 21.

[0177] The crack 43 in the drug layer 41 can be formed, for example, by bending the balloon 10 in the long axis direction after forming the drug layer 41 through the cut 22 of the protrusion 21. In this case, it is preferable that the balloon 10 is bent in the long axis direction at or near the location of the cut 22 of the protrusion 21.

[0178] When a crack 43 is formed on the surface of the agent layer 41 provided in the cut 22, the thickness of the agent layer 41 at the bottom 22B of the cut 22 refers to the thickness of the agent layer 41 excluding the area where the crack 43 is formed. That is, it is the length of a straight line drawn from the bottom 22B of the cut 22 to the shortest point 42 connecting the surface of the agent layer 41, but the shortest point 42 is the shortest point from the bottom 22B to the surface of the agent layer 41 excluding the area where the crack 43 is formed.

[0179] like Figure 19 As shown, a protective layer 45 may also be provided on the outer surface of the agent layer 41, and the protective layer 45 is configured to cover at least a portion of the crack 43. Figure 19 The text shows that in Figure 15 In the cross-sectional view of the convex strip 21 shown, a protective layer 45 is provided on the outer surface of the drug layer 41 to cover the crack 43. By providing the protective layer 45 on the outer surface of the drug layer 41 to cover at least a portion of the crack 43, it is possible to prevent bodily fluid from entering the crack 43 during delivery of the balloon 10 to the narrow portion, thus preventing the drug layer 41 from falling off or the drug from dissolving from the drug layer 41. Preferably, the protective layer 45 is provided on the outer surface of the drug layer 41 to cover the entire crack 43. Furthermore, it is preferable that the protective layer 45 extends into the interior of the crack 43 and fills at least a portion of the crack 43.

[0180] like Figure 12 As shown, when the drug layer 41 is also provided on the side surface 21S of the protrusion 21, cracks (not shown) may also be formed in the drug layer 41 provided on the side surface 21S of the protrusion 21 along the base 21B of the side surface 21S of the protrusion 21. In this case, when the balloon 10 is viewed from the outside, it is preferable that the cracks are formed on the surface of the drug layer 41 along the extension direction of the base 21B, that is, the extension direction of the boundary between the region 27 where the protrusion exists and the region 28 where the protrusion does not exist.

[0181] When a crack 43 forms on the surface of the agent layer 41 provided at the cut 22, the requirement A described above only needs to be met by the agent layer 41 except for the portion where the crack 43 is formed. For example, it can be assumed that the agent is also present in the crack 43. The same applies to the above-mentioned requirements C, requirements E, and various configurations of the other agent layers 41.

[0182] In the aforementioned protrusion 21, the distal surface 25 of the proximal outer edge 23P of the cut 22, i.e., the proximal segment 24P, is formed to extend proximally from the bottom 22B of the cut 22 toward the top 22A, and the distal outer edge 23D of the cut 22, i.e., the distal surface 26 of the distal segment 24D, is formed to extend distally from the bottom 22B of the cut 22 toward the top 22A, but as... Figures 20-22 As shown, the cut 22 may also include a specific cut 22 having a drug layer 41 that satisfies the following requirement F. Figures 20-22 The diagram shows a specific example of the configuration of the interruption portion 24, and shows a cross-sectional view through the top 21A of the protrusion 21 and along the extension direction and radial direction of the protrusion 21.

[0183] (Requirement F) In a specific cut 22, the distal surface 25 of the proximal convex segment 24P has a portion extending radially from the bottom 22B toward the top 22A of the specific cut 22 and / or toward the distal side in a cross section passing through the top 21A of the convex segment 21 and along the extension direction and radial direction of the convex segment 21; the proximal surface 26 of the distal convex segment 24D has a portion extending radially from the bottom 22B toward the top 22A of the specific cut 22 and / or toward the proximal side in a cross section passing through the top 21A of the convex segment 21 and along the extension direction and radial direction of the convex segment 21.

[0184] exist Figure 20 In the proximal convex segment 24P, the distal surface 25 has a portion extending distally from the bottom 22B of the specific incision 22 toward the top 22A, and the proximal surface 26 of the distal convex segment 24D has a portion extending proximally from the bottom 22B of the specific incision 22 toward the top 22A. Figure 21In the proximal lateral convex segment 24P, the distal surface 25 has a portion extending radially from the bottom 22B of the specific cut 22 toward the top 22A, and the proximal surface 26 of the distal lateral convex segment 24D has a portion extending radially from the bottom 22B of the specific cut 22 toward the top 22A. Figure 22 In the proximal convex segment 24P, the distal surface 25 has a portion extending radially from the bottom 22B of the specific incision 22 toward the top 22A and a portion extending toward the distal side, and the proximal surface 26 of the distal convex segment 24D has a portion extending radially from the bottom 22B of the specific incision 22 toward the top 22A and a portion extending toward the proximal side. If the specific incision 22 is formed in this way, when the balloon 10 is inflated, a larger portion of the top 21A of the convex segment 21 contacts the vessel wall, further enhancing the scoring function based on the convex segment 21.

[0185] like Figure 21 and Figure 22 As shown, in a specific incision 22, the distal surface 25 of the proximal convex segment 24P may also have a portion extending proximally from the bottom 22B toward the top 22A, and the proximal surface 26 of the distal convex segment 24D may also have a portion extending distally from the bottom 22B toward the top 22A. Furthermore, the portion of the distal surface 25 of the proximal convex segment 24P extending radially from the bottom 22B toward the top 22A and / or extending distally of the specific incision 22 preferably accounts for a larger proportion of the depth direction of the specific incision 22, and the portion of the proximal surface 26 of the distal convex segment 24D extending radially from the bottom 22B toward the top 22A and / or extending proximally of the specific incision 22 preferably accounts for a larger proportion of the depth direction of the specific incision 22. Specifically, the radial length of the distal surface 25 of the proximal convex segment 24P, extending radially from the bottom 22B of the specific cut 22 towards the top 22A and / or extending radially to the distal side, is preferably 50% or more, more preferably 60% or more, further preferably 70% or more, and even more preferably 80% or more of the radial length of the specific cut 22. The radial length of the proximal surface 26 of the distal convex segment 24D, extending radially from the bottom 22B of the specific cut 22 towards the top 22A and / or extending radially to the proximal side, is preferably 50% or more, more preferably 60% or more, further preferably 70% or more, and even more preferably 80% or more of the radial length of the specific cut 22.

[0186] A drug layer 41 is provided at a specific incision 22. This arrangement of the drug layer 41 ensures reliable delivery of the drug to the surface of the vessel wall without detachment when the balloon 10 is delivered to the treatment area, such as a stenosis. The drug layer 41 at the specific incision 22 is protected by the distal surface 25 of the proximal lateral convex segment 24P and the proximal surface 26 of the distal lateral convex segment 24D. Therefore, even when the surface of the balloon 10 contacts the vessel wall when the balloon 10 is delivered to the treatment area, the drug layer 41 is less likely to detach from the specific incision 22. Furthermore, when the balloon 10 is inflated, the drug layer 41 at the specific incision 22 is pushed radially inward by the balloon body 16, thereby enabling delivery to the surface of the vessel wall.

[0187] like Figure 23 As shown, at least one of the distal surface 25 of the proximal convex segment 24P and the proximal surface 26 of the distal convex segment 24D can also be formed concavely. Specifically, the distal surface 25 of the proximal convex segment 24P can also be formed to be concave proximally in a cross-section along the outer surface of the balloon body 16, and the proximal surface 26 of the distal convex segment 24D can also be formed to be concave distally in a cross-section along the outer surface of the balloon body 16. The cross-section along the outer surface of the balloon body 16 refers to the cross-section after the convex segment 21 has been removed with a plane parallel to the outer surface of the balloon body 16, and refers to the cross-section along the long axis and circumferential direction of the balloon 10. Furthermore, in Figure 23 The drug layer 41 is omitted from the diagram. If the distal surface 25 of the proximal lateral convex segment 24P and / or the proximal surface 26 of the distal lateral convex segment 24D are formed in this way, a greater amount of drug can be stably retained in the specific incision 22.

[0188] In the case where the distal surface 25 of the proximal convex segment 24P has a portion extending radially from the bottom 22B of the specific cut 22 toward the top 22A and / or toward the distal side, and the proximal surface 26 of the distal convex segment 24D has a portion extending radially from the bottom 22B of the specific cut 22 toward the top 22A and / or toward the proximal side, a portion of the distal surface 25 of the proximal convex segment 24P may also contact a portion of the proximal surface 26 of the distal convex segment 24D (not shown). If the specific cut 22 is formed in this way, the scoring function based on the convex segment 21 can be further utilized. In this case, preferably at least a portion of the radially outer half of the distal surface 25 of the proximal convex segment 24P contacts at least a portion of the radially outer half of the proximal surface 26 of the distal convex segment 24D.

[0189] Preferably, the ridge 21 is formed such that in a vertical cross-section along the long axis of the balloon 10, it has a portion whose width narrows towards the top 21A, and no portion whose width widens towards the top 21A. This improves the scoring function based on the ridge 21. For example... Figure 26 As shown, the ridge 21 can also be formed such that its width narrows in a stepped manner toward the top 21A. In this case, the ridge 21 only needs to have a portion that narrows in a stepped manner toward the top 21A in at least a portion from the base 21B to the top 21A.

[0190] Figures 24-26 The image shows a configuration example where the raised strips 21 are formed in a stepped shape. Figure 24 It shows Figure 7 The example shown is a modified example of the cut 22 of the convex strip 21, and is a cross-sectional view of the convex strip 21 through the top 21A of the convex strip 21 and along the extending direction and radial direction of the convex strip 21. Figure 25 It shows Figure 20 The example shown is a modified example of the cut 22 of the convex strip 21, and is a cross-sectional view of the convex strip 21 through the top 21A of the convex strip 21 and along the extending direction and radial direction of the convex strip 21. Figure 26 It shows Figure 24 and Figure 25 The XXVI-XXVI sectional view of the cut 22 of the convex strip 21 shown. Figures 24-26 In this design, the rib 21 is formed having a first stepped portion 31 adjacent to the outer surface of the balloon body 16 and a second stepped portion 32 on the side closer to the top 21A, with its width narrowing in a stepped manner towards the top 21A. In this case, the cut 22 of the rib 21 can be formed only on the portion of the stepped rib 21 on the side of the top 21A, for example, the cut 22 can be formed on the second stepped portion 32, but not on the first stepped portion 31. Alternatively, a drug layer 41 can be provided in the cut 22 formed on the second stepped portion 32. By providing the drug layer 41 in the cut 22 formed in this way, the drug layer 41 can be easily and stably maintained in the cut 22 of the rib 21.

[0191] Figure 27 The image shows the setting in Figure 24 The illustrated example shows a configuration where the agent layer 41 of the cut 22 of the raised strip 21 has a crack 43. In this case, it is preferable that the crack 43 is formed on the surface of the agent layer 41 along the bottom 22B of the cut 22 formed in the second step portion 32.

[0192] The first step portion 31 and the second step portion 32 can be made of the same material or of different materials. For example, both the first step portion 31 and the second step portion 32 can be made of resin, or the first step portion 31 can be made of metal and the second step portion 32 can be made of resin.

[0193] The surface free energy E1 of the material constituting the surface of the preferred protrusion 21 of the balloon 10 is different from the surface free energy E2 of the material constituting the outer surface of the balloon body 16. Surface free energy affects wettability and affinity with liquids; the greater the surface free energy, the better the affinity with liquids, and the smaller the surface free energy, the more likely it is to repel liquids. The drug layer 41 can be formed, for example, by coating the surface of the balloon 10 with a drug solution and then drying it. However, by appropriately setting the surface free energy E1 of the material constituting the surface of the protrusion 21 and the surface free energy E2 of the material constituting the outer surface of the balloon body 16, the drug layer 41 can be selectively disposed at desired locations on the surface of the balloon 10.

[0194] The surface free energy E1 of the material constituting the surface of the protrusion 21 and the surface free energy E2 of the material constituting the outer surface of the balloon body 16 can be determined by measuring the contact angle of each material with a droplet in the gas phase and the contact angle of a bubble in the liquid phase. The contact angle can be measured using a commercially available contact angle meter, and the surface free energy can be calculated based on the measurement results of the contact angle.

[0195] Preferably, the surface free energy E1 of the material constituting the surface of the protrusion 21 is greater than the surface free energy E2 of the material constituting the outer surface of the balloon body 16. By setting the surface free energies of the materials constituting the surface of the protrusion 21 and the outer surface of the balloon body 16 in this way, the drug solution is more likely to adhere to the surface of the protrusion 21, and a thicker drug layer 41 can be formed on the surface of the protrusion 21.

[0196] The surface free energy E2 of the material constituting the outer surface of the balloon body 16 is preferably 30 dyne / cm or more and 60 dyne / cm or less. More preferably, the surface free energy E2 is 35 dyne / cm or more, even more preferably 40 dyne / cm or more, and still more preferably 55 dyne / cm or less. If the surface free energy E2 is such a value, when the drug solution is applied to the outer surface of the balloon body 16, the drug solution is more likely to remain sufficiently on the outer surface of the balloon body 16.

[0197] The surface free energy E1 of the material constituting the surface of the protrusion 21 is preferably 5 times or more than the surface free energy E2 of the material constituting the outer surface of the balloon body 16, more preferably 8 times or more, and even more preferably 10 times or more. By setting the surface free energy E1 of the material constituting the surface of the protrusion 21 in this way, it is easier to form a thicker drug layer 41 around the protrusion 21. The upper limit of the ratio of the surface free energy E1 to the surface free energy E2 is not particularly limited, and the surface free energy E1 can be less than 1000 times, less than 500 times, less than 100 times, or less than 50 times the free energy E2.

[0198] The balloon 10 is preferably inserted into the guiding catheter or sheath in a contracted state when it is delivered to the treatment site, such as a stenosis of the blood vessel. At this time, the balloon 10 is preferably appropriately folded in a way that reduces its radial size.

[0199] Figure 28 and Figure 29 The text shows how to make Figure 4 The illustrated example shows the configuration of the balloon 10 when it contracts and folds. Figure 28 and Figure 29 The image shows a cross-sectional view of the balloon 10 in its contracted state, cut perpendicular to its long axis at the incision 22 of the protrusion 21. Additionally, it shows a section from the incision 22 to the region 27 where the protrusion does not exist. Figure 11 An example of the pharmaceutical layer 41 shown.

[0200] like Figure 28 and Figure 29 As shown, preferably in the contracted state of the balloon 10, the inner surface of the balloon body 16 is folded back in the region 28 where the ridges are absent, forming a folded blade portion 29 by overlapping the regions 28 where the ridges are absent. The folded blade portion 29 is overlapped on the outer surface of the balloon 10. The folded blade portion 29 is formed by folding back the regions 28 where the ridges are absent in the balloon body 16 at the bend line 30, where the regions 28 overlap each other. At the bend line 30, the regions 28 where the ridges are absent are folded back with the inner surface of the balloon body 16 facing inward. Therefore, when viewed from the outside of the balloon 10, the bend line 30 is formed as a convex bend. Preferably, the folded blade portion 29 is formed only by the regions 28 where the ridges are absent in the balloon body 16, and is formed without including the region 27 where the ridges are present.

[0201] Preferably, the bend line 30 extends substantially parallel to the extending direction of the ridge 21. The area 28 where the ridge is absent can be folded back in a manner that forms a distinct crease at the bend line 30, or its front end can be smoothly folded back. Furthermore, the area 28 where the ridge is absent in the balloon body 16 typically has a certain degree of thickness and elasticity, so the front end of the area 28 where the ridge is absent is smoothly folded back at the bend line 30. In this case, viewed in a vertical cross-section along the long axis of the balloon 10, the front end obtained by folding back the area 28 where the ridge is absent becomes the bend line 30.

[0202] Preferably, the bend line 30 is formed at least in the straight tube portion 13. Therefore, it is preferable that the balloon 10 has a folded blade portion 29 formed in the straight tube portion 13 by overlapping the area 28 where the convex strip does not exist, and the folded blade portion 29 is overlapped and disposed on the outer surface of the straight tube portion 13.

[0203] In the straight tube portion 13, a bend line may also be formed on one and / or the other side of the circumferential direction relative to the bend line 30, such that the outer surface of the balloon body portion 16 is folded back (viewed from the outside of the balloon 10, it is a concave bend line). In this case, it is preferable that the bend line, which is a concave bend line, forms the base of the folded blade portion 29.

[0204] The bend line 30 may be formed only once or more in a region 28 where the convex strip is absent. Preferably, the bend line 30 is formed once or twice in a region 28 where the convex strip is absent. Figure 28 In the middle, the bend line 30 is formed in a region 28 where the convex strip does not exist. Figure 29 In this configuration, two bend lines 30 are formed in a region 28 where the ridge is absent. When only one bend line 30 is formed in a region 28 where the ridge is absent, it is preferable that, when viewed from a vertical cross-section along the long axis of the balloon 10, the folded blade portion 29 tilts to one side in the circumferential direction. When two bend lines 30 are formed in a region 28 where the ridge is absent, it is preferable that, when viewed from a vertical cross-section along the long axis of the balloon 10, the two folded blade portions 29 tilt in opposite directions in the circumferential direction, tilting towards the ridge 21. Thus, in the contracted state of the balloon 10, the ridge 21 is easily protected by the folded blade portions 29.

[0205] In one embodiment, when the balloon 10 is in the contracted state, the folding blade portion 29 can also be configured to cover the top 21A of the protrusion 21. In this case, the drug layer 41 provided on the end face 22 of the protrusion 21 is protected by the folding blade portion 29, and the drug layer 41 is not easily detached from the balloon 10 before the balloon 10 is delivered to the treatment target.

[0206] In another embodiment, when the balloon 10 is in the contracted state, the folded blade portion 29 can also be overlapped on the outer surface of the straight tube portion 13 without covering the top 21A of the protrusion 21. In this case, when the balloon 10 is expanded in the narrow portion, the protrusion 21 quickly engages with the narrow portion, making it easy for the narrow portion to be effectively expanded by the balloon 10.

[0207] exist Figure 28 In a region 28 where the ridge 21 is absent, a folded blade portion 29 is formed. The folded blade portion 29 is configured to cover the top 21A of the ridge 21, but... Figure 28 In this configuration, the folded blade portion 29 can also be overlapped on the outer surface of the straight tube portion 13 without covering the top 21A of the protrusion 21. Figure 29 In a region 28 where the ridge does not exist, two folded blade portions 29 are formed and configured to overlap on the outer surface of the straight tube portion 13 in such a way that they do not cover the top 21A of the ridge 21. However, the folded blade portions 29 may also be configured to cover the top 21A of the ridge 21.

[0208] This application claims the benefit of priority based on Japanese Patent Application Nos. 2024-010303 and 2024-010305, filed January 26, 2024; Japanese Patent Application No. 2024-077680, filed May 13, 2024; and Japanese Patent Application No. 2024-232072, filed December 27, 2024. For reference, the entire contents of the descriptions of Japanese Patent Application Nos. 2024-010303 and 2024-010305, filed January 26, 2024; Japanese Patent Application No. 2024-077680, filed May 13, 2024; and Japanese Patent Application No. 2024-232072, filed December 27, 2024, are incorporated herein by reference.

[0209] Explanation of reference numerals in the attached figures

[0210] 1…Balloon catheter; 2…Axis; 3…Inner axis; 4…Outer axis; 4A…Proximal outer axis; 4B…Distal outer axis; 5…Hub; 6…Fluid injection section; 7…Guidewire orifice; 8…Tip; 9…X-ray-proof marker; 10…Balloon; 11…Proximal sleeve section; 12…Proximal cone section; 13…Straight tube section; 14…Distal cone section; 15…Distal sleeve section; 16…Balloon body section; 17…Proximal region; 18…Middle region; 19…Distal region; 21…Protrusion; 21A…Top; 21B…Base; 21S…Side; 22…Incision; 22A…Top; 22B…bottom; 23P…outer edge of the proximal side (of the cut); 23D…outer edge of the distal side (of the cut); 24…rib segment; 24P…proximal rib segment; 24D…distal rib segment; 25…distal surface (of the proximal rib segment); 26…proximal surface (of the distal rib segment); 27…area where the rib exists; 28…area where the rib does not exist; 29…folded blade portion; 30…bend line; 31…first step portion; 32…second step portion; 41…pharmaceutical layer; 42…shortest point from the bottom of the rib cut to the surface of the pharmaceutical layer; 43…crack; 45…protective layer.

Claims

1. A balloon for a balloon catheter, having a long axis extending from the proximal side to the distal side, a radial direction perpendicular to said long axis direction, and a circumferential direction, characterized in that, The balloon has a balloon body and a ridge protruding radially outward from the outer surface of the balloon body, with a cut formed in the ridge. A pharmaceutical layer is provided at the cut of the convex strip.

2. The balloon according to claim 1, characterized in that, The balloon has: a straight tube portion; a proximal cone portion located closer to the straight tube portion than the straight tube portion; and a distal cone portion located distal to the straight tube portion. The agent layer is provided in the cut of the protrusion located in the straight tube section.

3. The balloon according to claim 1, characterized in that, The incision includes a specific incision in which the drug layer is provided, satisfying the following requirements. Requirements: The outer surface of the balloon is divided into regions where ridges are present and regions where ridges are absent. In a cross-section perpendicular to the long axis direction at the bottom of the specific cut, the average thickness of the drug layer at the specific cut is greater than the average thickness of the drug layer in the region where the ridge is absent.

4. The balloon according to claim 1, characterized in that, The cut includes specific cuts that meet the following requirements: Requirements: In a cross-section passing through the top of the ridge and along the extension direction and radial direction of the ridge, at least a portion of the outer edge of the proximal side of the particular cut is located closer to the proximal side than the imaginary line connecting the top and bottom of the outer edge of the proximal side of the particular cut, and / or at least a portion of the outer edge of the distal side of the particular cut is located further to the distal side than the imaginary line connecting the top and bottom of the outer edge of the distal side of the particular cut.

5. The balloon according to claim 1, characterized in that, The incision includes a specific incision in which the drug layer is provided, satisfying the following requirements. Requirements: In a cross-section passing through the top of the ridge and along the extension direction and radial direction of the ridge, the surface of the agent layer disposed at the specific cut is recessed radially inward, and the agent layer is present at the bottom of the specific cut.

6. The balloon according to claim 1, characterized in that, The incision includes a specific incision in which the drug layer is provided, satisfying the following requirements. Requirements: In a cross-section passing through the top of the ridge and along the extension direction and radial direction of the ridge, the shortest distance from the outer edge of the particular cut covered by the agent layer to the surface of the agent layer is longest outside the bottom of the particular cut.

7. The balloon according to claim 1, characterized in that, The incision includes a specific incision in which the drug layer is provided, satisfying the following requirements. Requirements: The proximal and / or distal surfaces of the specific cut are formed to be radially recessed inward in a vertical section along the extension direction of the convex strip.

8. The balloon according to claim 1, characterized in that, The raised rib is divided into multiple raised rib segments by the cut. The incision includes a specific incision in which the drug layer is provided, satisfying the following requirements. Requirements: The distal surface of the proximal rib segment adjacent to the proximal side of the specific incision has a portion extending radially from the bottom to the top of the specific incision and / or extending toward the distal side in a cross-section passing through the top of the rib and along the extension direction and radial direction of the rib. The proximal surface of the rib segment adjacent to the distal side of the specific cut, i.e., the distal rib segment, has a portion extending radially from the bottom toward the top of the specific cut and / or toward the proximal side in a cross-section passing through the top of the rib and along the extension direction and radial direction of the rib.

9. The balloon according to claim 8, characterized in that, A portion of the distal surface of the proximal lateral convex segment contacts a portion of the proximal surface of the distal lateral convex segment.

10. The balloon according to claim 1, characterized in that, In a vertical cross-section along the extending direction of the convex rib, the convex rib is formed such that its width narrows in a stepped manner towards the top of the convex rib, and it has a first stepped portion adjacent to the outer surface of the balloon body and a second stepped portion closer to the top side thereon. The cut is formed in the second step portion, but not in the first step portion.

11. The balloon according to claim 1, characterized in that, Cracks extending along the bottom of the cut are formed on the surface of the agent layer.

12. The balloon according to claim 1, characterized in that, The pharmaceutical agent constituting the pharmaceutical layer is crystalline.

13. The balloon according to claim 1, characterized in that, The surface free energy of the material constituting the surface of the convex strip is different from the surface free energy of the material constituting the outer surface of the balloon body.

14. The balloon according to claim 1, characterized in that, The surface free energy of the material constituting the surface of the convex strip is greater than the surface free energy of the material constituting the outer surface of the balloon body.

15. The balloon according to claim 1, characterized in that, The raised strip may be made of resin, metal, or a combination thereof.

16. The balloon according to claim 1, characterized in that, The outer surface of the balloon is divided into regions where ridges are present and regions where ridges are absent. In the contracted state of the balloon, the inner surface of the balloon body is folded back in the area where the ridges are not present, forming a folded blade portion by overlapping the areas where the ridges are not present. The folded blade portion overlaps on the outer surface of the balloon and covers the top of the convex strip.

17. The balloon according to claim 1, characterized in that, The outer surface of the balloon is divided into regions where ridges are present and regions where ridges are absent. In the contracted state of the balloon, the inner surface of the balloon body is folded back in the area where the ridges are not present, forming a folded blade portion by overlapping the areas where the ridges are not present. The folded blade portion is disposed overlapping the outer surface of the balloon in a manner that does not cover the top of the convex strip.

18. A balloon catheter, characterized in that, The balloon is equipped with any one of claims 1 to 17.

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