WO2024106081A1 - Balloon for balloon catheter, balloon catheter, and manufacturing method of balloon catheter - Google Patents

Balloon for balloon catheter, balloon catheter, and manufacturing method of balloon catheter Download PDF

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Publication number
WO2024106081A1
WO2024106081A1 PCT/JP2023/036992 JP2023036992W WO2024106081A1 WO 2024106081 A1 WO2024106081 A1 WO 2024106081A1 JP 2023036992 W JP2023036992 W JP 2023036992W WO 2024106081 A1 WO2024106081 A1 WO 2024106081A1
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WO
WIPO (PCT)
Prior art keywords
balloon
straight tube
ridge
drug layer
longitudinal direction
Prior art date
Application number
PCT/JP2023/036992
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French (fr)
Japanese (ja)
Inventor
和明 生駒
真弘 小嶋
崇亘 ▲濱▼淵
Original Assignee
株式会社カネカ
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Application filed by 株式会社カネカ filed Critical 株式会社カネカ
Publication of WO2024106081A1 publication Critical patent/WO2024106081A1/en

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M25/00—Catheters; Hollow probes
    • A61M25/10—Balloon catheters

Definitions

  • the present invention relates to a balloon for a balloon catheter having a drug retained on its surface, a balloon catheter equipped with the balloon, and a method for manufacturing a balloon catheter equipped with the balloon.
  • stenosis in blood vessels which are the channels through which blood circulates in the body
  • blood vessels which are the channels through which blood circulates in the body
  • stenosis in the coronary arteries that supply blood to the heart can lead to serious diseases such as angina pectoris and myocardial infarction.
  • angioplasty PTA, PTCA, etc.
  • PTA angioplasty
  • PTCA PTCA
  • Balloon catheters with ridges on the surface of the balloon are known (see, for example, Patent Documents 1 to 5).
  • the ridges of the balloon can be inserted into the narrowed area when the balloon is inflated, effectively expanding the narrowed area.
  • restenosis can occur at the expanded narrowed area, and balloon catheters with a drug retained on the balloon surface are also known to reduce the frequency of such restenosis (restenosis rate) (see, for example, Patent Documents 4 to 7).
  • the drug can be transferred to the inner wall of the body cavity, such as the blood vessel wall, by expanding the balloon at the narrowed or diseased area of the body cavity, such as a blood vessel, and it is expected that the occurrence of restenosis, etc. can be suppressed.
  • a balloon catheter with a drug retained on the balloon 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 narrowed or affected area of a body cavity, such as a blood vessel; however, it is desirable for the drug to be stably retained in the balloon when the balloon is delivered to the narrowed or affected area.
  • the present invention has been made in consideration of the above circumstances, and its object is to provide a balloon for a balloon catheter that can stably deliver a drug to a narrowed or affected area of a body cavity, such as a blood vessel, and a balloon catheter equipped with said balloon.
  • the present invention also provides a method for manufacturing a balloon catheter equipped with the balloon of the present invention.
  • a balloon for a balloon catheter having a longitudinal direction extending from a proximal side to a distal side and a radial direction perpendicular to the longitudinal direction,
  • the balloon has a straight tube portion, a proximal tapered portion located proximally of the straight tube portion, and a distal tapered portion located distally of the straight tube portion
  • the straight pipe portion has a balloon main body and a protrusion protruding radially outward on an outer surface of the balloon main body, and a protrusion-existing region and a protrusion-free region are formed on the outer surface of the straight pipe portion
  • the protrusion has a first side surface on one side and a second side surface on the other side with respect to an imaginary line passing through a top of the protrusion and
  • the method for producing the balloon catheter of the present invention is as follows. [9] A step of preparing a balloon having a longitudinal direction extending from a proximal side to a distal side and a radial direction perpendicular to the longitudinal direction, the balloon having a straight tube portion, a proximal tapered portion located proximal to the straight tube portion, and a distal tapered portion located distal to the straight tube portion, the straight tube portion having a balloon main body portion and a convex streak protruding radially outward and extending in the longitudinal direction on an outer surface of the balloon main body portion, the straight tube portion having a convex streak-presenting region and a convex streak-free region formed on the outer surface of the straight tube portion; a coating step of coating an outer surface of the straight tube portion with a drug solution while the balloon is inflated, to form a drug layer at a base of a first side surface on one side of the protrusion stripe, the drug layer being thicker than a base of
  • the balloon for balloon catheter of the present invention has a convex rib on the outer surface of the straight tube part of the balloon, a drug layer is provided at the base of the first side of one side of the convex rib thicker than the base of the second side of the other side, and the folding wing part is overlapped on the outer surface of the straight tube part so as to cover the convex rib from the first side side, and the balloon is folded. Therefore, in the balloon catheter equipped with the balloon of the present invention, the drug is stably held in the folded state of the balloon, and the folded state of the balloon is easily held stably.
  • the folding wing part is overlapped on the outer surface of the straight tube part so as to cover the convex rib from the first side side where the drug layer is relatively thick, the drug layer is protected by the folding wing part, and the drug layer is less likely to fall off before the balloon is delivered to the narrowed part or the lesion part of the body cavity such as a blood vessel.
  • the drug layer functions as an adhesive, and can increase the adhesion between the folding wing part and the first side of the convex rib.
  • the folded state of the balloon is stabilized, and the drug is delivered to the narrowed part or the lesion part in a stably protected state.
  • the balloon catheter of the present invention can be easily manufactured according to the manufacturing method of the balloon catheter of the present invention.
  • FIG. 1 shows an example of the configuration of a balloon catheter according to an embodiment of the present invention, and is a side view of the balloon catheter excluding the drug layer on the balloon surface.
  • FIG. 2 is a perspective view of a balloon provided in the balloon catheter shown in FIG. 1 .
  • 3 shows a cross-sectional view of the balloon catheter shown in FIG. 1 taken along line III-III.
  • 4 shows a cross-sectional view of the balloon catheter shown in FIG. 1 taken along line IV-IV.
  • 1 shows an example of a vertical cross-sectional view of a straight portion of a balloon with a drug layer in the longitudinal direction.
  • 6 is an enlarged cross-sectional view of the ridges and their surroundings of the balloon shown in FIG. 5 .
  • FIG. 13 shows another example of an enlarged cross-sectional view of the area around the convex ridge of a balloon having a drug layer. 13 shows another example of an enlarged cross-sectional view of the area around the convex ridge of a balloon having a drug layer.
  • FIG. 6 illustrates an example of a vertical cross-sectional view in the longitudinal direction of the balloon shown in FIG. 5 in a deflated and folded state.
  • FIG. 6 shows another example of a vertical cross-sectional view in the longitudinal direction of the balloon shown in FIG. 5 in a deflated and folded state.
  • 1 shows a schematic diagram of a method for forming a drug layer on a balloon surface.
  • FIG. 1 shows an example of the configuration of a balloon catheter in an expanded state, with the drug layer of the balloon removed.
  • Fig. 1 shows a side view of the balloon catheter
  • Fig. 2 shows a perspective view of the balloon equipped in the balloon catheter shown in Fig. 1
  • Fig. 3 shows a III-III cross-sectional view of the balloon catheter shown in Fig. 1
  • Fig. 4 shows an IV-IV cross-sectional view of the balloon catheter shown in Fig. 1.
  • Fig. 1 shows an example of the configuration of a rapid exchange type balloon catheter.
  • the balloon catheter 1 has a shaft 2 and a balloon 10 provided on the outside of the shaft 2.
  • the balloon catheter 1 has a proximal side and a distal side, and the balloon 10 is provided on the distal part of the shaft 2.
  • the proximal side of the balloon catheter 1 refers to the direction toward the user's (operator's) hand in the extension direction of the balloon catheter 1, and the distal side refers to the opposite direction of the proximal side, i.e., the direction toward the treatment target.
  • the direction from the proximal side to the distal side of the balloon catheter 1 is referred to as the longitudinal direction.
  • the balloon catheter 1 is configured so that fluid is supplied to the inside of the balloon 10 through the shaft 2, and the expansion and contraction of the balloon 10 can be controlled using an indeflator (a balloon pressurizer/depressurizer).
  • the fluid may be a pressurized fluid pressurized by a pump or the like.
  • the fluid supplied to the inside of the balloon 10 is referred to as the "balloon expansion fluid.”
  • the shaft 2 is composed of, for example, an inner shaft 3 and an outer shaft 4.
  • the inner shaft 3 is disposed in the inner cavity of the outer shaft 4.
  • the inner shaft 3 can function as a passage for a guide wire that guides the progress of the shaft 2, and when the balloon catheter 1 is used, the guide wire is inserted into the inner cavity of the inner shaft 3.
  • the space between the inner shaft 3 and the outer shaft 4 can function as a flow path for the balloon expansion fluid.
  • a guidewire port 7 is provided midway from the distal to the proximal side of the shaft 2, and the proximal end of the inner shaft 3 is connected to the guidewire port 7, and the distal end of the inner shaft 3 extends to the distal part of the shaft 2, forming a guidewire insertion passage that extends from the guidewire port 7 to the distal part of the shaft 2.
  • the outer shaft 4 may have a proximal outer shaft 4A and a distal outer shaft 4B, in which case it is preferable that the inner shaft 3 is disposed in the lumen of the distal outer shaft 4B.
  • the proximal outer shaft 4A and the distal outer shaft 4B may be made of the same material, or may be made of different materials.
  • the proximal outer shaft 4A is made of resin or metal
  • the distal outer shaft 4B is made of resin.
  • the outer shaft 4 may not be divided into the proximal outer shaft 4A and the distal outer shaft 4B, but may be made of a single member, or the proximal outer shaft 4A and the distal outer shaft 4B may be further made of multiple tube members.
  • a hub 5 is preferably provided on the proximal side of the shaft 2.
  • the hub 5 preferably has a fluid injection section 6 that is connected to the flow path of the balloon expansion fluid in the shaft 2.
  • the balloon 10, shaft 2 (inner shaft 3, outer shaft 4), and hub 5 can be joined using conventional joining means such as adhesives or heat welding.
  • the balloon catheter may be an over-the-wire type balloon catheter in which the inner shaft extends from the distal to the proximal part of the shaft and a guidewire passage is formed from the distal to the proximal side of the shaft.
  • the flow path of the balloon expansion fluid and the guidewire passage provided in the shaft extend to the hub, and that the hub is configured to have a fluid injection section communicating with the flow path of the balloon expansion fluid and a treatment section communicating with the guidewire passage.
  • the hub has a bifurcated structure, with the fluid injection section provided on one side of the bifurcated branch and the treatment section provided on the other side.
  • the outer surface of the shaft 2 is preferably coated.
  • a rapid exchange type balloon catheter 1 it is preferable that the outer surface of one or both of the proximal outer shaft 4A and the distal outer shaft 4B is coated, and it is more preferable that the outer surfaces of both the proximal outer shaft 4A and the distal outer shaft 4B are coated.
  • an over-the-wire type balloon catheter it is preferable that the outer surface of the outer shaft is appropriately coated.
  • the coating can be a hydrophilic coating or a hydrophobic coating depending on the purpose.
  • the outer surface of the shaft 2 can be coated by immersing the shaft 2 in a hydrophilic or hydrophobic coating agent, applying a hydrophilic or hydrophobic coating agent to the outer surface of the shaft 2, or covering the outer surface of the shaft 2 with a hydrophilic or hydrophobic coating agent.
  • the coating agent may contain drugs or additives.
  • Hydrophilic coating agents include hydrophilic polymers such as polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyvinylpyrrolidone, and methyl vinyl ether maleic anhydride copolymers, as well as hydrophilic coating agents made from any combination of these.
  • Hydrophobic coating agents include polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), perfluoroalkoxyalkane (PFA), silicone oil, hydrophobic urethane resin, carbon coat, diamond coat, diamond-like carbon (DLC) coat, ceramic coat, and substances with low surface free energy terminated with alkyl groups or perfluoroalkyl groups.
  • PTFE polytetrafluoroethylene
  • FEP fluorinated ethylene propylene
  • PFA perfluoroalkoxyalkane
  • silicone oil silicone oil
  • hydrophobic urethane resin carbon coat
  • diamond coat diamond coat
  • DLC diamond-like carbon
  • ceramic coat and substances with low surface free energy terminated with alkyl groups or perfluoroalkyl groups.
  • a tip tip 8 is provided at the distal end of the balloon catheter 1.
  • the tip tip 8 may be provided as a separate member from the inner shaft 3, distal to the distal end of the inner shaft 3, or the inner shaft 3 may extend distal to the distal end of the balloon 10, so that the distal end of the inner shaft 3 functions as the tip tip 8.
  • the shaft 2 may have an X-ray opaque marker 9 disposed at the portion where the balloon 10 is located in the longitudinal direction, so that the position of the balloon 10 can be confirmed under X-ray fluoroscopy.
  • the X-ray opaque marker 9 may be disposed, for example, on the inner shaft 3 disposed inside the balloon 10, and is preferably disposed at positions corresponding to both ends of the straight tube portion of the balloon 10, or may be disposed at a position corresponding to the center of the straight tube portion of the balloon 10.
  • the balloon 10 has a longitudinal direction and a radial direction, and is formed into a cylindrical shape with openings on the proximal and distal sides (see FIG. 2).
  • the radial direction of the balloon 10 means a direction perpendicular to the longitudinal direction, extending radially from the center of the balloon 10.
  • the balloon 10 also has a circumferential direction, which is the direction along the outer periphery of the balloon 10 in an expanded state in a vertical cross section of the longitudinal direction of the balloon 10.
  • the balloon 10 has a straight tube section 13, a proximal taper section 12 located proximal to the straight tube section 13, and a distal taper section 14 located distal to the straight tube section 13 in the longitudinal direction.
  • the straight tube section 13 is formed in an approximately cylindrical shape extending in the longitudinal direction, and is formed to have the largest radial length (outer diameter) in the balloon 10.
  • the proximal taper section 12 is located proximal to the straight tube section 13 and connects to the proximal end of the straight tube section 13.
  • the proximal taper section 12 is formed so that the outer diameter decreases with increasing distance from the straight tube section 13.
  • the distal taper section 14 is located distal to the straight tube section 13 and connects to the distal end of the straight tube section 13.
  • the distal taper section 14 is formed so that the outer diameter decreases with increasing distance from the straight tube section 13.
  • the balloon 10 preferably further has a proximal sleeve portion 11 located proximal to the proximal taper portion 12 and a distal sleeve portion 15 located distal to the distal taper portion 14.
  • the proximal sleeve portion 11 is located proximal to the proximal taper portion 12 and is connected to the proximal end of the proximal sleeve portion 11.
  • the proximal sleeve portion 11 is formed in a substantially cylindrical shape.
  • the distal sleeve portion 15 is located distal to the distal taper portion 14 and is connected to the distal end of the distal sleeve portion 15.
  • the distal sleeve portion 15 is formed in a
  • the straight tube section 13 comes into sufficient contact with the narrowed area, making it easier to perform treatment such as expanding the narrowed area.
  • the balloon 10 has a proximal tapered section 12 and a distal tapered section 14, when the balloon 10 is deflated, the outer diameter of the proximal and distal ends of the balloon 10 can be reduced to reduce the step between the shaft 2 and the balloon 10, making it easier to insert the balloon 10 into a body cavity or a forceps channel of an endoscope.
  • the inner shaft 3 extends distally from the distal end of the outer shaft 4, and that the inner shaft 3 extends through the internal space of the balloon 10 from the proximal sleeve portion 11 to the distal sleeve portion 15. It is also preferable that the outer surface of the inner shaft 3 is joined to the internal surface of the distal sleeve portion 15 of the balloon 10, and the outer surface of the outer shaft 4 is joined to the internal surface of the proximal sleeve portion 11 of the balloon 10.
  • the balloon 10 is preferably made of a resin, more preferably a thermoplastic resin. This makes it easier to manufacture the balloon 10 by molding.
  • resins that make up the balloon 10 include polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer, polyester resins such as polyethylene terephthalate and polyester elastomer, polyurethane resins such as polyurethane and polyurethane elastomer, polyphenylene sulfide resins, polyamide resins such as polyamide and polyamide elastomer, fluorine-based resins, silicone resins, and natural rubbers such as latex rubber. These may be used alone or in combination of two or more.
  • polyamide resins polyester resins, and polyurethane resins are preferably used.
  • elastomer resins are preferably used in terms of thinning and flexibility of the balloon 10.
  • nylon 12 and nylon 11 are examples of polyamide resins that are suitable for the balloon 10, and nylon 12 is preferably used because it is relatively easy to mold when blow molding.
  • polyamide elastomers such as polyether ester amide elastomers and polyamide ether elastomers are preferably used in terms of thinning and flexibility of the balloon 10.
  • polyether ester amide elastomers are preferably used because they have high yield strength and provide good dimensional stability to the balloon 10.
  • the balloon 10 has a ridge 17 on the outer surface of the straight tube section 13.
  • the ridge 17 on the outer surface of the straight tube section 13 gives the balloon 10 a scoring function, and when the balloon 10 is expanded at a narrowed portion of a blood vessel, it can bite into the calcified narrowed portion and create a crack in the narrowed portion. This allows the narrowed portion to be expanded while suppressing dissection of the vascular intima. It also makes it possible to increase the strength of the balloon 10 and suppress overexpansion when pressurized.
  • the balloon 10 can also be used to treat narrowed portions or lesions in body cavities other than blood vessels, but the following description will be given taking as an example a case in which the balloon 10 is applied to a narrowed portion of a blood vessel.
  • Figure 5 shows a vertical cross-section in the longitudinal direction of the straight tube section 13 of the balloon 10
  • Figures 6 to 8 show enlarged cross-sections of the ridges 17 and the surrounding area of the balloon 10.
  • Figures 5 to 8 show a balloon 10 in which a drug layer 31 is provided on the outer surface of the straight tube section 13.
  • Figure 5 shows an example configuration in which a drug layer 31 is provided on the outer surface of the balloon 10 shown in Figures 2 and 4, and the ridges 17 are provided at three locations in the circumferential direction of the straight tube section 13.
  • the straight tube section 13 of the balloon 10 has a cylindrical balloon main body section 16, and a convex rib 17 is provided on the outer surface of the balloon main body section 16.
  • the convex rib 17 is provided so as to protrude radially outward from the outer surface of the balloon main body section 16.
  • the balloon 10 has a convex rib region 21 and a convex rib non-existent region 22 formed on the outer surface of the straight tube section 13.
  • the ridge 17 has an apex 17A and a base 17B (see Figures 6 to 8).
  • the apex 17A refers to the tip of the ridge 17, i.e., the part located radially outward of the ridge 17, and the base 17B refers to the boundary between the side surface 18 of the ridge 17 and the balloon body 16, i.e., the part located radially inward of the ridge 17.
  • the ridges 17 can be made of resin, for example. If the ridges 17 are made of resin, the balloon 10 having the ridges 17 can be manufactured by resin molding, making manufacturing easier. In this case, the ridges 17 and the balloon body 16 are preferably made of the same resin, and the ridges 17 and the balloon body 16 are preferably integrally formed.
  • the balloon body 16 may have an inner layer and an outer layer, and in this case, the ridges 17 are preferably made of the same resin as the outer layer of the balloon body 16. This makes it less likely that the ridges 17 will unintentionally fall off the balloon body 16.
  • the ridges 17 and the balloon body 16 may be made of different resins, as long as there is a certain degree of compatibility between the resin that makes up the ridges 17 and the resin that makes up the balloon body 16.
  • the ridges 17 may be made of metal, or a combination of metal and resin. In this case, it is preferable that the portion including the apex 17A of the ridges 17 is made of metal. This makes it easier for the ridges 17 to create a crack in the narrowed area or to cut open the narrowed area when the balloon 10 is inflated.
  • the entire ridges 17 may be made of metal, or the portion including the base 17B of the ridges 17 may be made of resin, and the portion including the apex 17A of the ridges 17 may be made of metal. Therefore, it is preferable that the ridges 17 are made of resin, metal, or a combination thereof.
  • the balloon main body 16 is defined as a portion having a cylindrical shape.
  • the straight pipe section 13 is composed of the balloon main body 16 excluding the ridges 17 protruding radially outward.
  • the outer surface of the balloon main body 16 can be considered to be formed in a cylindrical shape. Therefore, in a vertical cross section in the longitudinal direction of the straight pipe section 13, the outer shape of the balloon main body 16 is formed in a substantially circular shape, which allows the balloon main body 16 and the ridges 17 to be distinguished from each other.
  • the balloon main body 16 and the ridges 17 are shown separated by dotted lines.
  • the ridge-present region 21 is composed of the balloon main body 16 and the ridges 17, and the ridge-free region 22 is composed of the balloon main body 16.
  • the convex ribs 17 are provided on the outer surface of the straight tube section 13 so as to extend in a ridge-like manner. It is preferable that the convex ribs 17 are provided so as to extend in the longitudinal direction. In this case, the convex ribs 17 may extend approximately parallel to the longitudinal direction of the balloon 10, or may extend in a spiral shape in the longitudinal direction. Note that it is preferable that the convex ribs 17 extend approximately parallel to the longitudinal direction of the balloon 10, in order to enhance the scoring function of the balloon 10 and to facilitate the manufacture of a balloon 10 having the convex ribs 17.
  • Only one or more convex ribs 17 may be provided in a vertical cross section in the longitudinal direction of the straight pipe section 13.
  • only one convex rib 17 is provided in the straight pipe section 13
  • only one non-convex rib region 22 is formed in the straight pipe section 13
  • multiple convex ribs 17 are provided in the straight pipe section 13
  • multiple non-convex rib regions 22 are formed in the straight pipe section 13.
  • the non-convex rib regions 22 are formed in the same number as the convex ribs 17.
  • the convex ribs 17 are provided in three locations in the circumferential direction of the straight pipe section 13 of the balloon 10.
  • the ridges 17 are preferably provided at multiple different circumferential positions on the straight tube section 13 of the balloon 10. That is, the ridges 17 are preferably provided at multiple locations on the balloon 10 in the circumferential direction. In this case, the ridges 17 are preferably arranged at approximately equal intervals on the straight tube section 13 of the balloon 10 in the circumferential direction. This makes it possible to create cracks in multiple locations on the narrowed section when the balloon 10 is expanded.
  • the ridges 17 are preferably provided at two or more locations on the circumferential direction of the balloon 10, more preferably three or more locations, and preferably eight or fewer locations, and more preferably six or fewer locations. In this case, the circumferential interval of the ridges 17 is preferably longer than the circumferential length of one ridge 17.
  • the cross-sectional shape of the convex ribs 17 is not particularly limited.
  • the shape of the convex ribs 17 in a vertical cross section in the longitudinal direction of the straight pipe section 13 may be a polygon such as a triangle or a rectangle, a partial shape of a circle such as a semicircle or a sector, an approximately circular shape, a wedge shape, a convex shape, a spindle shape, an irregular shape, etc.
  • Polygons include polygons with clear corner apexes and straight sides, as well as rounded polygons with rounded corners and polygons with at least some of the sides curved. It is preferable that the convex ribs 17 are formed so that they narrow toward the apex 17A.
  • Figures 6 to 8 show examples of various cross-sectional shapes of the convex ribs 17.
  • the convex ribs 17 are formed so that their width narrows steplessly toward the apex 17A.
  • the convex ribs 17 are formed so that their width narrows stepwise toward the apex 17A.
  • the convex ribs 17 are formed so that they have a portion where their width widens and a portion where their width narrows toward the apex 17A. Details of each shape of the convex ribs 17 shown in Figures 6 to 8 will be described later.
  • the height of the ridge 17 is preferably 0.2 times or more the width (maximum width) of the ridge 17. If the ridge 17 is formed in this manner, when the balloon 10 is expanded at the narrowed portion, the ridge 17 is more likely to bite into the narrowed portion, and the scoring function of the ridge 17 can be improved. In addition, as described below, it becomes easier to form a drug layer on the side surface 18 of the ridge 17.
  • the width of the ridge 17 described here means the circumferential length of the ridge 17.
  • the ridge 17 may be formed so that it is at its widest at the base 17B, so that the ridge 17 is stably installed on the outer surface of the balloon body portion 16.
  • the height of the ridge 17 is more preferably 0.4 times or more the width of the ridge 17, more preferably 0.7 times or more, and more preferably 2.0 times or less, more preferably 1.8 times or less, and even more preferably 1.5 times or less.
  • the thickness of the portion where the ridges 17 are provided i.e., the thickness of the ridge-present region 21, is preferably formed thicker than the thickness of the portion where the ridges 17 are not provided, i.e., the thickness of the ridge-free region 22. This can improve the scoring function of the ridges 17.
  • the thickness (maximum thickness) of the ridge-present region 21 is preferably 1.5 times or more, more preferably 2.0 times or more, and even more preferably 2.5 times or more, the thickness (maximum thickness) of the ridge-free region 22.
  • the ridges 17 are preferably provided over at least 1/2 of the longitudinal length of the straight tube section 13, more preferably over at least 2/3 of the longitudinal length, and even more preferably over at least 3/4 of the longitudinal length. This allows cracks to be created over a wide range of the narrowed area when the balloon 10 is expanded.
  • the ridges 17 may also be provided on the outer surface of the proximal taper section 12 and/or the distal taper section 14. In Figures 1 and 2, the ridges 17 are provided so as to extend from the proximal taper section 12 through the straight tube section 13 to the distal taper section 14.
  • the balloon 10 may have an inner ridge that protrudes radially inward on the inner surface of the balloon 10 (not shown).
  • the ridge 17 and the inner ridge may be located at the same position in the longitudinal or circumferential direction of the balloon 10, and it is preferable that they are integrally molded, so that a portion of the balloon 10 may be formed thick.
  • a drug layer 31 is provided on the outer surface of the straight tube portion 13 of the balloon 10.
  • the drug contained in the drug layer 31 is not particularly limited as long as it is a pharmacologically active substance, and examples of such drugs include drugs that are acceptable as medicines, such as gene therapy drugs, non-gene therapy drugs, small molecules, and cells.
  • drugs that are acceptable as medicines, such as gene therapy drugs, non-gene therapy drugs, small molecules, and cells.
  • anti-restenosis drugs such as antiproliferative agents and immunosuppressants can be preferably used as the drug, and specifically, drugs such as paclitaxel, sirolimus (rapamycin), everolimus, and zotarolimus can be used. Only one type of these drugs may be used, or two or more types may be used.
  • the drug layer 31 may contain, in addition to the pharmacologically active substance, auxiliary agents for improving the dispersibility, solubility, migration to the vascular wall, and storage stability of the drug.
  • auxiliary agents for improving the dispersibility, solubility, migration to the vascular wall, and storage stability of the drug.
  • auxiliary agents include stabilizers, binders, disintegrants, moisture-proofing agents, preservatives, and dissolution aids.
  • lactose sucrose, maltose, dextrin, xylitol, erythritol, mannitol, ethylenediamine, potassium iodide, urea, polysorbate, dibutylhydroxytoluene, polyethylene glycol, lipids, sodium pyrosulfite, ascorbic acid, tocopherol, benzoic acid, paraoxybenzoic acid esters, polyacrylic acid, polylactic acid, polyglycolic acid, hyaluronic acid, chitosan, and gelatin.
  • the drug layer 31 may have a protective layer to prevent the drug from dissolving in the blood or falling off during delivery to the stenotic area.
  • the protective layer is preferably included as part of the drug layer 31 and constitutes the outermost layer of the drug layer 31.
  • the protective layer is composed of, for example, a water-soluble polymer, and can be formed from, for example, carboxymethylcellulose, hydroxypropylcellulose, methylcellulose, hydroxyethylcellulose, polyvinyl alcohol, alginic acid, pectin, gum arabic, gellan gum, guar gum, xanthan gum, carrageenan, gelatin, etc.
  • the drug layer 31 is provided on the outer surface of the straight tube section 13 including the side surface 18 of the convex rib 17, and in a vertical cross section of the straight tube section 13 in the longitudinal direction, the drug layer 31 at the base 17B of one of the two side surfaces 18 is provided thicker than the drug layer 31 at the base 17B of the other side surface 18.
  • the thickness of the drug layer 31 at the base 17B of the first side surface 18A is thicker than the thickness of the drug layer 31 at the base 17B of the second side surface 18B.
  • the second side surface 18B of the ridge 17 ensures the ability to penetrate into the narrowed area, and the first side surface 18A of the ridge 17 holds more drug, allowing the drug to be efficiently delivered from the inner surface of the blood vessel wall to the inside of the expanded narrowed area.
  • the thickness of drug layer 31 at base 17B of ridge 17 means the shortest length from base 17B of ridge 17 to the surface of drug layer 31 in a vertical cross section in the longitudinal direction of straight tube section 13 (the length of arrow 32 in Figures 6 to 8). It is anticipated that cracks may develop on the surface of drug layer 31 due to the dry state. In such a case, the thickness of drug layer 31 at base 17B of ridge 17 is defined as the shortest length to the surface of drug layer 31 excluding the location where the cracks have developed.
  • the thickness of the drug layer 31 at the base 17B of the first side surface 18A in at least one of the multiple ridges 17 is thicker than the thickness of the drug layer 31 at the base 17B of the second side surface 18B.
  • the thickness of the drug layer 31 at the base 17B of the first side surface 18A in all of the multiple ridges 17 is formed to be thicker than the thickness of the drug layer 31 at the base 17B of the second side surface 18B.
  • the circumferential positional relationship between the first side surface 18A and the second side surface 18B of the convex rib 17 is not particularly limited, and for example, when viewing the balloon 10 from the distal side, the left side surface 18 of the convex rib 17 may be the first side surface 18A, or the right side surface 18 may be the first side surface 18A.
  • the circumferential positional relationship between the first side surface 18A and the second side surface 18B is the same for all multiple convex ribs 17, and when viewing the balloon 10 from the distal side, for example, the right side surface of the convex rib 17 is the first side surface 18A and the left side surface 18 is the second side surface 18B.
  • the thickness of the drug layer 31 at the base 17B of the first side 18A is preferably 1.2 times or more, more preferably 1.5 times or more, and even more preferably 1.8 times or more, of the thickness of the drug layer 31 at the base 17B of the second side 18B.
  • the upper limit of the ratio of the thickness of the drug layer 31 at the base 17B of the first side 18A to the thickness of the drug layer 31 at the base 17B of the second side 18B is not particularly limited, and the drug layer 31 may not be present at the base 17B of the second side 18B, or may be present at a very thin thickness.
  • the thickness of the drug layer 31 at the base 17B of the first side 18A may be 100 times or less, 50 times or less, 30 times or less, 20 times or less, or 10 times or less, of the thickness of the drug layer 31 at the base 17B of the second side 18B.
  • the thickness of the drug layer 31 at the base 17B of the first side 18A of the convex rib 17 is thicker than the thickness of the drug layer 31 at the base 17B of the second side 18B in at least a portion of the longitudinal direction of the straight tube section 13; preferably, the drug layer 31 is so formed in more than half of the central 1/2 region in the longitudinal direction of the straight tube section 13; more preferably, the drug layer 31 is so formed in more than 2/3 of the central 1/2 region in the longitudinal direction of the straight tube section 13; and even more preferably, the drug layer 31 is so formed in the entire central 1/2 region in the longitudinal direction of the straight tube section 13.
  • the straight tube section 13 is cut radially at 6 locations at 10% intervals over a range of 25% to 75% and the thickness of the drug layer 31 at the base 17B of each cut cross section is measured, and it is preferable that the drug layer 31 is formed in this manner at three or more locations.
  • This makes it possible to determine that the drug layer 31 at the base 17B of the first side surface 18A of the convex rib 17 is formed thicker than the drug layer 31 at the base 17B of the second side surface 18B in more than half of the central 1/2 region in the longitudinal direction of the straight tube section 13.
  • the drug layer 31 may be formed such that the drug layer 31 at the base 17B of the first side surface 18A of the convex rib 17 is thicker than the drug layer 31 at the base 17B of the second side surface 18B over the entire longitudinal direction of the straight tube section 13.
  • the drug layer 31 is present on the first side surface 18A of the convex rib 17 at point 17C, which is 50% of the height of the convex rib 17 (see Figure 6). If the drug layer 31 is provided on the convex rib 17 in this manner, the drug can be delivered deeper inside the blood vessel wall.
  • Point 17C which is 50% of the height of the convex rib 17, represents the relative radial position of the convex rib 17 as a percentage, when the radial position at base 17B on side surface 18 is 0%, and the radial position at top 17A is 100%.
  • the drug layer 31 is present over the entire 0% to 50% height of the convex rib 17 on the first side surface 18A.
  • the drug layer 31 may be present on the first side 18A of the ridge 17 at a point that is 75% of the height of the ridge 17, and in this case, it is preferable that the drug layer 31 is present over the entire first side 18A from 0% to 75% of the height of the ridge 17.
  • a drug layer 31 is provided on the outer surface of the straight tube section 13, not only on the side surface 18 of the ridges 17 but also in the non-ridge regions 22. If a drug layer 31 is provided in the non-ridge regions 22, when the balloon 10 is expanded at the stenosis, the drug can be delivered to a wide area of the inner surface of the blood vessel at the stenosis.
  • the ridges 17 may be formed to have a portion that narrows toward the apex 17A and not have a portion that widens toward the apex 17A. That is, the side surface 18 of the ridges 17 may be formed to have a portion that approaches the imaginary straight line 17L toward the apex 17A with respect to the imaginary straight line 17L that passes through the apex 17A of the ridges 17 and extends radially, and not have a portion that moves away from the imaginary straight line 17L toward the apex 17A.
  • the ridges 17 may be formed to narrow toward the apex 17A from the base 17B to the entire apex 17A. That is, the side surface 18 of the ridge 17 may be formed so as to approach the imaginary straight line 17L from the base 17B of the ridge 17 to the entire top 17A toward the top 17A.
  • the ridges 17 may be formed so that their width narrows steplessly toward the apex 17A as shown in FIG. 6, or may be formed so that their width narrows stepwise toward the apex 17A as shown in FIG. 7.
  • the side surfaces 18 of the ridges 17 may be formed in a vertical cross section in the longitudinal direction of the straight pipe section 13 in a straight line extending obliquely with respect to the imaginary straight line 17L, in a curved line bulging radially outward (which may include a straight line portion), or in a curved line bulging radially inward (which may include a straight line portion).
  • the ridges 17 may have at least a portion from the base 17B to the apex 17A where their width narrows stepwise toward the apex 17A.
  • the ridge 17 is preferably formed with the drug layer 31 as follows. That is, the ridge 17 has a first step portion 19 adjacent to the outer surface of the balloon body 16 and a second step portion 20 on the apex 17A side of the first step portion 19, as a portion in which the width narrows stepwise toward the apex 17A, and it is preferable that the thickness of the drug layer 31 at the base 19B of the first side 18A of the first step portion 19 is formed thicker than the thickness of the drug layer 31 at the base 20B of the first side 18A of the second step portion 20.
  • the drug layer 31 By forming the drug layer 31 in this manner, the second step portion 20 of the ridge 17 is more likely to bite into the narrowed portion, and the narrowed portion can be effectively expanded by the balloon 10.
  • the drug layer 31 is thicker at the base 19B of the first side 18A of the first step portion 19 of the ridge 17, and migration of smooth muscle cells present in the tunica media of the vascular wall to the inner surface of the blood vessel can be suppressed.
  • the drug layer 31 may not be present at the base 20B of the first side surface 18A of the second step portion 20, and the drug layer 31 may not be present at all on the side surface 18 of the second step portion 20.
  • the thickness of the drug layer 31 at the base 20B of the second step portion 20 means the shortest length from the base 20B of the second step portion 20 of the ridge 17 to the surface of the drug layer 31 in a vertical cross section in the longitudinal direction of the straight tube portion 13.
  • the base 19B of the first step portion 19 of the ridge 17 coincides with the base 17B of the ridge 17
  • the thickness of the drug layer 31 at the base 19B of the first step portion 19 of the ridge 17 corresponds to the thickness of the drug layer 31 at the base 17B of the ridge 17.
  • the ridge 17 may be formed to have a portion that widens toward the apex 17A, and a portion that narrows toward the apex 17A from the portion.
  • the first side 18A of the ridge 17 may be formed to have a portion 18R that moves away from the imaginary straight line 17L toward the apex 17A with respect to the imaginary straight line 17L that passes through the apex 17A of the ridge 17 and extends in the radial direction, and a portion 18S that moves closer to the imaginary straight line 17L toward the apex 17A from the portion.
  • a portion of the first side 18A of the ridge 17 is formed to be recessed. Therefore, it is possible to hold more medicine in the recessed portion of the first side 18A of the ridge 17.
  • the portion 18R where the first side surface 18A moves away from the imaginary straight line 17L toward the top 17A is preferably formed in at least a part of the range of at least 0% to 30% of the height of the convex streak 17, and is preferably not formed in the range of 50% to 100% of the height of the convex streak 17. This allows more medicine to be held by the base 17B of the first side surface 18A of the convex streak 17.
  • the drug layer 31 may be provided on the outer surface of the proximal tapered section 12 and/or the outer surface of the distal tapered section 14 in addition to the outer surface of the straight tube section 13. This allows the drug to be delivered to a wide area of the stenosis.
  • the balloon 10 is contracted and folded after the drug layer 31 is provided on the outer surface of the straight tube portion 13.
  • the radial size is reduced, making it easier to insert the balloon 10 into a guiding catheter or sheath and deliver it to the treatment target area, such as a narrowed part of a blood vessel.
  • FIG. 9 and 10 show an example in which the balloon 10 shown in Fig. 5 is deflated and folded.
  • the straight tube section 13 is folded back at the fold line 24 formed in the non-convex streak region 22 with the inner surface of the balloon body 16 facing inward, forming a folded wing section 23 in which the non-convex streak region 22 is overlapped, and the folded wing section 23 is overlapped on the outer surface of the straight tube section 13 so as to cover at least a portion of the convex streak 17.
  • the folding wing portion 23 has a first portion 23A on one side of the folding line 24 and a second portion 23B on the other side, and the ridge-free region 22 is folded back at the folding line 24, so that the first portion 23A and the second portion 23B of the folding wing portion 23 are overlapped, and the overlapped first portion 23A and the second portion 23B of the folding wing portion 23 are overlapped on the outer surface of the straight pipe portion 13 so as to cover at least a part of the ridge 17.
  • the balloon 10 is folded by overlapping the folding wing portion 23 with the ridge-free region 22 overlapping each other on the outer surface of the straight pipe portion 13 in this way.
  • the fold lines 24 are preferably formed so as to extend approximately parallel to the extension direction of the ridges 17.
  • the non-ridge region 22 may be folded back so as to form a clear crease at the fold line 24, or may be folded back with a rounded tip. Note that since the non-ridge region 22 of the balloon body 16 usually has a certain degree of thickness and elasticity, the non-ridge region 22 is folded back with a rounded tip at the fold line 24. In this case, when viewed in a vertical cross section in the longitudinal direction of the straight tube section 13, the tip where the non-ridge region 22 is folded back becomes the fold line 24.
  • the fold line 24 is formed as a mountain fold when viewed from the outside of the balloon 10. It is preferable that the folding wing portion 23 is formed only from the non-ridge region 22 of the balloon body portion 16, and is not formed including the ridge region 21.
  • the straight tube portion 13 may have a fold line (a valley fold line when viewed from the outside of the balloon 10) that is folded back with the outer surface of the balloon body portion 16 facing inward on one side and/or the other side of the fold line 24 in the circumferential direction.
  • the fold line that becomes the valley fold line preferably forms the base of the folding wing portion 23.
  • the folding wing portion 23 is inclined to one side in the circumferential direction.
  • the folding wing portion 23 is overlapped on the outer surface of the straight tube portion 13 so as to cover at least a portion of the convex rib 17 from the first side surface 18A side.
  • the drug layer 31 is provided relatively thickly on the base 17B of the first side surface 18A of the convex rib 17, but by overlapping the folding wing portion 23 from the first side surface 18A side with the convex rib 17 on which the drug layer 31 is provided, the drug layer 31 is protected by the folding wing portion 23, and the drug layer 31 is less likely to fall off before the balloon 10 is delivered to the treatment target area.
  • the drug layer 31 functions as an adhesive, improving the adhesion between the folding wing portion 23 and the first side 18A of the ridge 17. As a result, the folded state of the balloon 10 is stabilized, and the drug can be stably delivered to the treatment target area.
  • the folding wing portion 23 covers the top 17A of the ridge 17. If the balloon 10 is folded in this manner, the drug layer 31 provided on the first side surface 18A of the ridge 17 is protected by the folding wing portion 23, making it difficult for the drug layer 31 to fall off the balloon 10 before the balloon 10 is delivered to the treatment target area. In addition, the top 17A of the ridge 17 is not exposed when the balloon 10 is delivered to the treatment target area, and the folded balloon 10 can be smoothly inserted into a guiding catheter or sheath.
  • the folding wing portion 23 may cover the second side surface 18B of the ridge 17, and the fold line 24 of the folding wing portion 23 may be positioned so as to overlap the ridge-free region 22. This allows the balloon 10 to be folded more tightly.
  • the fold line 24 of the folding wing portion 23 may be positioned so as to overlap an adjacent folding wing portion 23 in the circumferential direction.
  • the method for manufacturing a balloon catheter according to an embodiment of the present invention includes a step of preparing a balloon having a ridge on its outer surface (hereinafter referred to as the "balloon preparation step”); a step of applying a drug solution to the outer surface of the straight tube section of the balloon while the balloon is inflated, and forming a drug layer at the base of a first side surface on one side of the ridge that is thicker than the base of a second side surface on the other side (hereinafter referred to as the "drug layer formation step”); and a step of deflating the balloon, folding back the straight tube section in the non-ridge area to form a folding wing section, and folding the balloon by overlapping the folding wing section on the outer surface of the straight tube section so as to cover at least a portion of the ridge from the first side surface side (hereinafter referred to as the "balloon folding step”).
  • the balloon 10 described above is prepared. That is, the balloon 10 has a longitudinal direction extending from the proximal side to the distal side and a radial direction perpendicular to the longitudinal direction, and has a straight tube section 13, a proximal tapered section 12 located proximal to the straight tube section 13, and a distal tapered section 14 located distal to the straight tube section 13, and the straight tube section 13 has a cylindrical balloon main body section 16 and a convex rib 17 that protrudes radially outward from the outer surface of the balloon main body section 16 and extends in the longitudinal direction.
  • the above explanation is referred to for details of the configuration and preferred embodiments of the balloon 10.
  • a drug solution is applied to the outer surface of the straight pipe section 13, and a drug layer 31 is formed at the base 17B of the first side surface 18A on one side of the convex rib 17, which is thicker than the base 17B of the second side surface 18B on the other side.
  • the method of applying the drug solution is not particularly limited, and for example, the drug solution may be applied to the outer surface of the straight pipe section 13 with a brush, spray, coater, etc., or the drug solution may be applied to the outer surface of the straight pipe section 13 by immersing the balloon 10 in the drug solution. If necessary, the drug solution may be applied to the outer surface of the straight pipe section 13 after masking the parts where the drug layer 31 is not to be formed.
  • FIG. 11 shows a vertical cross-sectional view of the longitudinal direction of the balloon 10 shown in Figure 2, showing the state in which drug solution 33 is applied to the outer surface of the straight tube section 13 of the balloon 10.
  • the drug solution 33 applied to the outer surface of the straight tube section 13, particularly the convex rib non-existent region 22 moves circumferentially around the surface of the straight tube section 13 and accumulates on the side 18 of the convex rib 17, and a thicker drug layer 31 can be formed on the side 18 of the convex rib 17 and the base 17B.
  • a thicker drug layer 31 can be formed on the first side surface 18A of the protrusion 17.
  • Modes in which the balloon 10 is preferentially rotated in one direction around the central axis extending in the longitudinal direction include a mode in which the balloon 10 is rotated in only one direction around the central axis extending in the longitudinal direction, a mode in which the balloon 10 is rotated around the central axis extending in the longitudinal direction so that the number of rotations in one direction is greater than in the other directions, and a mode in which the balloon 10 is rotated around the central axis extending in the longitudinal direction at a faster rotation speed in one direction than in the other directions.
  • the chemical solution 33 preferably contains a solvent that dissolves or disperses the chemical.
  • concentration of the chemical in the chemical solution 33 there are no particular limitations on the concentration of the chemical in the chemical solution 33, and the concentration can be adjusted appropriately so that the chemical can be applied to the outer surface of the straight pipe section 13 and fluidity is ensured on the surface of the straight pipe section 13.
  • the method of applying the drug solution 33 is not particularly limited, but it is preferable to apply the drug solution 33 to the outer surface of the straight pipe section 13 by spraying as shown in FIG. 11, which makes it easy to widely apply any amount of drug solution 33 to the outer surface of the straight pipe section 13. It also makes it easy to form a drug layer 31 on the outer surface of the straight pipe section 13.
  • the drug solution 33 may be applied to the outer surface of the straight tube section 13 while the balloon 10 is rotated around a central axis extending in the longitudinal direction, or after the drug solution 33 is applied to the outer surface of the straight tube section 13, the balloon 10 may be rotated around a central axis extending in the longitudinal direction. In either case, the drug solution 33 applied to the outer surface of the straight tube section 13 can move circumferentially around the surface of the straight tube section 13 and accumulate at the base 17B of the ridge 17.
  • the balloon 10 may be rotated in only one direction around a central axis extending in the longitudinal direction, or may be rotated in both one direction and the opposite direction in turn.
  • the thickness of the drug layer 31 formed on the base 17B of the first side 18A and the base 17B of the second side 18B of the ridge 17 can be adjusted as desired.
  • the solvent may be evaporated by heating the balloon 10 to which the drug solution 33 has been applied, by placing the balloon 10 to which the drug solution 33 has been applied in a reduced pressure state, or by blowing air on the balloon 10 to which the drug solution 33 has been applied.
  • the solvent may be allowed to evaporate naturally while rotating the balloon 10.
  • the balloon 10 on which the drug layer 31 is formed is deflated, and the straight tube section 13 is folded back at the non-convex streak region 22 with the inner surface of the balloon body 16 facing inward to form the folded wing section 23 in which the non-convex streak region 22 is overlapped.
  • the straight tube section 13 is folded back at the folding line 24 with the inner surface of the balloon body 16 facing inward, thereby forming the folded wing section 23 in which the non-convex streak region 22 is overlapped.
  • the folded wing section 23 is then folded over on the outer surface of the straight tube section 13 so as to cover at least a portion of the convex streak 17 from the first side surface 18A side, thereby folding the balloon 10.
  • the folded wing portion 23 is preferably overlapped on the outer surface of the straight pipe portion 13 so as to cover the top 17A of the ridge 17, and may also be overlapped on the outer surface of the straight pipe portion 13 so as to cover the second side surface 18B of the ridge 17 and so that the tip of the folded wing portion 23, i.e., the fold line 24, overlaps with the ridge-free region 22.
  • SYMBOLS 1 Balloon catheter 2: Shaft 5: Hub 10: Balloon 11: Proximal sleeve section 12: Proximal tapered section 13: Straight tube section 14: Distal tapered section 15: Distal sleeve section 16: Balloon body section 17: Ridge, 17A: Top, 17B: Base 18: Side, 18A: First side, 18B: Second side 19: First stage section 20: Second stage section 21: Ridge-present region 22: Ridge-free region 23: Folding wing section 24: Folding line 31: Drug layer 32: Thickness of drug layer at base of rib 33: Drug solution

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Abstract

A balloon (10) for a balloon catheter, wherein: a straight tubular part (13) of the balloon (10) has a cylindrical balloon body (16) and a convex part (17) that protrudes radially outward on the outer surface of the balloon body (16); a convex part-including area (21) and a convex part-free area (22) are formed on the outer surface of the straight tubular part(13); a drug layer (31) is formed on the outer surface of the straight tubular part (13) including a first side (18A) of the convex part (17); the drug layer (31) is thicker at the base of the first side (18A) of the convex part (17) than at the base of a second side (18B); in the contracted state of the balloon (10), the straight tubular part (13) is folded back at a fold line (24) formed in the convex part-free area (22) to form a folded blade (23); and the folded blade (23) is overlaid on the outer surface of the straight tubular part (13) so that the convex part (17) is covered from the first side (18A) to thereby fold the balloon (10).

Description

バルーンカテーテル用バルーン、バルーンカテーテル、およびバルーンカテーテルの製造方法Balloon for balloon catheter, balloon catheter, and method for manufacturing balloon catheter
　本発明は、表面に薬剤が保持されたバルーンカテーテル用バルーンと、当該バルーンを備えたバルーンカテーテルと、当該バルーンを備えたバルーンカテーテルの製造方法に関するものである。 The present invention relates to a balloon for a balloon catheter having a drug retained on its surface, a balloon catheter equipped with the balloon, and a method for manufacturing a balloon catheter equipped with the balloon.
　体内で血液が循環するための流路である血管に狭窄が生じ、血液の循環が滞ることにより、様々な疾患が発生することが知られている。特に心臓に血液を供給する冠状動脈に狭窄が生じると、狭心症、心筋梗塞等の重篤な疾病をもたらすおそれがある。このような血管の狭窄部を治療する方法の一つとして、バルーンカテーテルを用いて狭窄部を拡張させる血管形成術（ＰＴＡ、ＰＴＣＡ等）がある。 It is known that stenosis in blood vessels, which are the channels through which blood circulates in the body, can lead to a variety of diseases due to stagnation of blood circulation. In particular, stenosis in the coronary arteries that supply blood to the heart can lead to serious diseases such as angina pectoris and myocardial infarction. One method of treating such vascular stenosis is angioplasty (PTA, PTCA, etc.), which uses a balloon catheter to expand the stenotic area.
　バルーンカテーテルには、バルーンの表面に凸条が設けられたものが知られている（例えば、特許文献１～５）。このようなバルーンカテーテルを用いれば、バルーンを拡張させた際に、バルーンの凸条を狭窄部に食い込ませて、狭窄部を効果的に拡張させることができる。一方、血管形成術の場合、拡張した狭窄部に再狭窄が生じることがあるが、そのような再狭窄が発生する頻度（再狭窄率）を低減するために、バルーン表面に薬剤を保持させたバルーンカテーテルも知られている（例えば、特許文献４～７）。このように薬剤が保持されたバルーンカテーテルを用いれば、血管等の体腔の狭窄部や病変部でバルーンを拡張することにより薬剤を血管壁等の体腔内壁へ移行させることができ、再狭窄等の発生抑制が期待できる。 Balloon catheters with ridges on the surface of the balloon are known (see, for example, Patent Documents 1 to 5). When such a balloon catheter is used, the ridges of the balloon can be inserted into the narrowed area when the balloon is inflated, effectively expanding the narrowed area. Meanwhile, in the case of angioplasty, restenosis can occur at the expanded narrowed area, and balloon catheters with a drug retained on the balloon surface are also known to reduce the frequency of such restenosis (restenosis rate) (see, for example, Patent Documents 4 to 7). When a balloon catheter with a drug retained in this way is used, the drug can be transferred to the inner wall of the body cavity, such as the blood vessel wall, by expanding the balloon at the narrowed or diseased area of the body cavity, such as a blood vessel, and it is expected that the occurrence of restenosis, etc. can be suppressed.
特開２００９－１１２３６１号公報JP 2009-112361 A 特開２０１７－１２６７８号公報JP 2017-12678 A 国際公開第２０２０／２５０６１１号International Publication No. 2020/250611 特表２００８－５３９９５９号公報JP 2008-539959 A 特開２０１３－１７６５０７号公報JP 2013-176507 A 特表２００８－５２９７４０号公報JP 2008-529740 A 特開２０１５－２１７２６０号公報JP 2015-217260 A
　バルーン表面に薬剤が保持されたバルーンカテーテルは、血管等の体腔の狭窄部や病変部でバルーンを拡張することにより薬剤を血管壁等の体腔内壁へ移行することができるが、狭窄部や病変部までバルーンを送達する際に、薬剤が安定してバルーンに保持されることが望ましい。本発明は前記事情に鑑みてなされたものであり、その目的は、血管等の体腔の狭窄部や病変部等に薬剤を安定して届けることができるバルーンカテーテル用バルーンと当該バルーンを備えたバルーンカテーテルを提供することにある。本発明はまた、本発明のバルーンを備えたバルーンカテーテルの製造方法も提供する。 A balloon catheter with a drug retained on the balloon 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 narrowed or affected area of a body cavity, such as a blood vessel; however, it is desirable for the drug to be stably retained in the balloon when the balloon is delivered to the narrowed or affected area. The present invention has been made in consideration of the above circumstances, and its object is to provide a balloon for a balloon catheter that can stably deliver a drug to a narrowed or affected area of a body cavity, such as a blood vessel, and a balloon catheter equipped with said balloon. The present invention also provides a method for manufacturing a balloon catheter equipped with the balloon of the present invention.
　前記課題を解決することができた本発明のバルーンカテーテル用バルーンおよび当該バルーンを備えたバルーンカテーテルは、下記の通りである。
［１］　近位側から遠位側に延びる長手方向と前記長手方向に垂直な径方向とを有するバルーンカテーテル用バルーンであって、
　前記バルーンは、直管部と、前記直管部よりも近位側に位置する近位側テーパー部と、前記直管部よりも遠位側に位置する遠位側テーパー部とを有し、
　前記直管部は、バルーン本体部と、前記バルーン本体部の外面に径方向の外方に突出した凸条とを有し、前記直管部の外面に凸条存在領域と凸条非存在領域が形成されており、
　前記直管部の長手方向の垂直断面において、前記凸条は、前記凸条の頂部を通り径方向に延びる仮想直線に対して一方側にある第１側面と他方側にある第２側面を有し、
　前記凸条の前記第１側面を含む前記直管部の外面に薬剤層が設けられており、
　前記凸条の前記第１側面の基部における前記薬剤層の厚みは、前記凸条の前記第２側面の基部における前記薬剤層の厚みよりも厚く、
　前記バルーンの収縮状態で、前記直管部は、前記バルーン本体部の内面を内側にして前記凸条非存在領域に形成された折り曲げ線で折り返されて、前記凸条非存在領域が重ね合わされた折り畳み羽根部が形成され、
　前記折り畳み羽根部が、前記第１側面側から前記凸条の少なくとも一部を覆うように前記直管部の外面に重ねられることにより、前記バルーンが折り畳まれているバルーンカテーテル用バルーン。
［２］　前記折り畳み羽根部は前記凸条の頂部を覆っている［１］に記載のバルーン。
［３］　前記折り畳み羽根部は前記凸条の前記第２側面を覆い、前記折り畳み羽根部の前記折り曲げ線が前記凸条非存在領域と重なる位置にある［１］または［２］に記載のバルーン。
［４］　前記直管部の長手方向の垂直断面において、前記凸条の前記第１側面は、前記仮想直線に対して、前記凸条の頂部に向かって前記仮想直線から遠ざかる部分と、当該部分よりも頂部側に、前記凸条の頂部に向かって前記仮想直線に近付く部分を有する［１］～［３］のいずれかに記載のバルーン。
［５］　前記直管部の長手方向の垂直断面において、前記凸条は、頂部に向かって段状に幅が狭まる部分を有する［１］～［４］のいずれかに記載のバルーン。
［６］　前記凸条は、前記頂部に向かって段状に幅が狭まる部分として、前記バルーン本体部の外面に隣接した第１段部分と、それよりも頂部側の第２段部分を有し、前記第１段部分の前記第１側面の基部における前記薬剤層の厚みは、前記第２段部分の前記第１側面の基部における前記薬剤層の厚みよりも厚い［５］に記載のバルーン。
［７］　前記凸条は、樹脂製、金属製、またはその組み合わせである［１］～［６］のいずれかに記載のバルーン。
［８］　［１］～［７］のいずれかに記載のバルーンを備えるバルーンカテーテル。 The balloon for a balloon catheter and the balloon catheter including said balloon of the present invention, which are able to solve the above-mentioned problems, are as follows.
[1] A balloon for a balloon catheter having a longitudinal direction extending from a proximal side to a distal side and a radial direction perpendicular to the longitudinal direction,
The balloon has a straight tube portion, a proximal tapered portion located proximally of the straight tube portion, and a distal tapered portion located distally of the straight tube portion,
The straight pipe portion has a balloon main body and a protrusion protruding radially outward on an outer surface of the balloon main body, and a protrusion-existing region and a protrusion-free region are formed on the outer surface of the straight pipe portion,
In a vertical cross section in a longitudinal direction of the straight pipe portion, the protrusion has a first side surface on one side and a second side surface on the other side with respect to an imaginary line passing through a top of the protrusion and extending in a radial direction,
A drug layer is provided on an outer surface of the straight tube portion including the first side surface of the convex strip;
a thickness of the drug layer at a base of the first side surface of the ridge is greater than a thickness of the drug layer at a base of the second side surface of the ridge;
When the balloon is in a deflated state, the straight tube portion is folded back along the folding line formed in the non-ridge region with the inner surface of the balloon body portion facing inward, and a folded wing portion is formed in which the non-ridge regions are overlapped,
A balloon for a balloon catheter, wherein the folding wing portion is overlapped on the outer surface of the straight tube portion so as to cover at least a portion of the convex strip from the first side surface side, thereby folding the balloon.
[2] The balloon described in [1], wherein the folded wing portion covers the top of the ridge.
[3] The balloon described in [1] or [2], wherein the folded wing portion covers the second side surface of the ridge, and the fold line of the folded wing portion is positioned so as to overlap the ridge-free region.
[4] The balloon according to any one of [1] to [3], wherein in a vertical cross section in the longitudinal direction of the straight tube portion, the first side surface of the ridge has, with respect to the imaginary line, a portion that moves away from the imaginary line toward the apex of the ridge, and a portion that is closer to the imaginary line toward the apex of the ridge than the portion toward the apex.
[5] The balloon according to any one of [1] to [4], wherein in a vertical cross section of the straight tube portion in the longitudinal direction, the convex strip has a portion whose width narrows stepwise toward an apex.
[6] The balloon described in [5], wherein the convex ridge has a first step portion adjacent to the outer surface of the balloon body and a second step portion further toward the apex, the first step portion narrowing in width stepwise toward the apex, and the thickness of the drug layer at the base of the first side surface of the first step portion is thicker than the thickness of the drug layer at the base of the first side surface of the second step portion.
[7] The balloon according to any one of [1] to [6], wherein the ridges are made of resin, metal, or a combination thereof.
[8] A balloon catheter comprising the balloon according to any one of [1] to [7].
　本発明のバルーンカテーテルの製造方法は、下記の通りである。
［９］　近位側から遠位側に延びる長手方向と前記長手方向に垂直な径方向とを有するバルーンであって、直管部と、前記直管部よりも近位側に位置する近位側テーパー部と、前記直管部よりも遠位側に位置する遠位側テーパー部とを有し、前記直管部が、バルーン本体部と、前記バルーン本体部の外面に径方向の外方に突出し長手方向に延在している凸条とを有とを有し、前記直管部の外面に凸条存在領域と凸条非存在領域が形成されたバルーンを準備する工程と、
　前記バルーンを拡張させた状態で、前記直管部の外面に薬液を塗布し、前記凸条の一方側の第１側面の基部に他方側の第２側面の基部よりも厚く薬剤層を形成する塗布工程と、
　前記バルーンを収縮させ、前記直管部を前記凸条非存在領域において前記バルーン本体部の内面を内側にして折り返して、前記凸条非存在領域が重ね合わされた折り畳み羽根部を形成し、前記折り畳み羽根部を、前記第１側面側から前記凸条の少なくとも一部を覆うように前記直管部の外面に重ねることにより、前記バルーンを折り畳む工程と
　を有するバルーンカテーテルの製造方法。
［１０］　前記塗布工程において、前記バルーンを前記長手方向に延びる中心軸を中心に回転させながら、前記直管部の外面に薬液を塗布する［９］に記載のバルーンカテーテルの製造方法。
［１１］　前記塗布工程において、前記直管部の外面に薬液を塗布した後、前記バルーンを前記長手方向に延びる中心軸を中心に回転させる［９］に記載のバルーンカテーテルの製造方法。
［１２］　前記塗布工程において、前記バルーンを回転させながら、前記薬液に含まれる溶媒の少なくとも一部を蒸発させる［９］～［１１］のいずれかに記載のバルーンカテーテルの製造方法。 The method for producing the balloon catheter of the present invention is as follows.
[9] A step of preparing a balloon having a longitudinal direction extending from a proximal side to a distal side and a radial direction perpendicular to the longitudinal direction, the balloon having a straight tube portion, a proximal tapered portion located proximal to the straight tube portion, and a distal tapered portion located distal to the straight tube portion, the straight tube portion having a balloon main body portion and a convex streak protruding radially outward and extending in the longitudinal direction on an outer surface of the balloon main body portion, the straight tube portion having a convex streak-presenting region and a convex streak-free region formed on the outer surface of the straight tube portion;
a coating step of coating an outer surface of the straight tube portion with a drug solution while the balloon is inflated, to form a drug layer at a base of a first side surface on one side of the protrusion stripe, the drug layer being thicker than a base of a second side surface on the other side;
and folding the balloon by deflating the balloon, folding back the straight tube portion at the non-ridge regions with the inner surface of the balloon body portion facing inward to form folded wing portions where the non-ridge regions are overlapped, and overlapping the folded wing portions on the outer surface of the straight tube portion so as to cover at least a portion of the ridges from the first side surface side.
[10] The method for manufacturing a balloon catheter according to [9], wherein in the coating step, the medicinal solution is applied to the outer surface of the straight tube portion while rotating the balloon about a central axis extending in the longitudinal direction.
[11] The method for manufacturing a balloon catheter according to [9], wherein in the coating step, after a medicinal solution is applied to the outer surface of the straight tube portion, the balloon is rotated around a central axis extending in the longitudinal direction.
[12] The method for manufacturing a balloon catheter according to any one of [9] to [11], wherein in the coating step, at least a portion of the solvent contained in the drug solution is evaporated while rotating the balloon.
　本発明のバルーンカテーテル用バルーンは、バルーンの直管部の外面に凸条が設けられ、凸条の一方側の第１側面の基部に他方側の第２側面の基部よりも厚く薬剤層が設けられており、第１側面側から凸条を覆うように折り畳み羽根部が直管部の外面に重ねられ、バルーンが折り畳まれている。そのため、本発明のバルーンを備えたバルーンカテーテルは、バルーンが折り畳まれた状態で薬剤が安定して保持されるとともに、バルーンの折り畳み状態が安定して保持されやすくなる。すなわち、折り畳み羽根部は、比較的薬剤層が厚く設けられた第１側面側から凸条を覆うように直管部の外面に重ねられているため、薬剤層が折り畳み羽根部によって保護され、バルーンが血管等の体腔の狭窄部や病変部に送達されるまでに薬剤層が脱落しにくくなる。また、薬剤層が接着剤として機能し、折り畳み羽根部と凸条の第１側面との密着性を高めることができる。その結果、バルーンの折り畳み状態が安定化され、薬剤が安定して保護された状態で狭窄部や病変部まで送達されるようになる。また、本発明のバルーンカテーテルの製造方法によれば、本発明のバルーンカテーテルを容易に製造することができる。 The balloon for balloon catheter of the present invention has a convex rib on the outer surface of the straight tube part of the balloon, a drug layer is provided at the base of the first side of one side of the convex rib thicker than the base of the second side of the other side, and the folding wing part is overlapped on the outer surface of the straight tube part so as to cover the convex rib from the first side side, and the balloon is folded. Therefore, in the balloon catheter equipped with the balloon of the present invention, the drug is stably held in the folded state of the balloon, and the folded state of the balloon is easily held stably. In other words, since the folding wing part is overlapped on the outer surface of the straight tube part so as to cover the convex rib from the first side side where the drug layer is relatively thick, the drug layer is protected by the folding wing part, and the drug layer is less likely to fall off before the balloon is delivered to the narrowed part or the lesion part of the body cavity such as a blood vessel. In addition, the drug layer functions as an adhesive, and can increase the adhesion between the folding wing part and the first side of the convex rib. As a result, the folded state of the balloon is stabilized, and the drug is delivered to the narrowed part or the lesion part in a stably protected state. Furthermore, the balloon catheter of the present invention can be easily manufactured according to the manufacturing method of the balloon catheter of the present invention.
本発明の実施の形態に係るバルーンカテーテルの構成例を表し、バルーン表面の薬剤層を除いたバルーンカテーテルの側面図を表す。FIG. 1 shows an example of the configuration of a balloon catheter according to an embodiment of the present invention, and is a side view of the balloon catheter excluding the drug layer on the balloon surface. 図１に示したバルーンカテーテルに備えられたバルーンの斜視図を表す。FIG. 2 is a perspective view of a balloon provided in the balloon catheter shown in FIG. 1 . 図１に示したバルーンカテーテルのＩＩＩ－ＩＩＩ断面図を表す。3 shows a cross-sectional view of the balloon catheter shown in FIG. 1 taken along line III-III. 図１に示したバルーンカテーテルのＩＶ－ＩＶ断面図を表す。4 shows a cross-sectional view of the balloon catheter shown in FIG. 1 taken along line IV-IV. 薬剤層を備えたバルーンの直管部の長手方向の垂直断面図の一例を表す。1 shows an example of a vertical cross-sectional view of a straight portion of a balloon with a drug layer in the longitudinal direction. 図５に示したバルーンの凸条周りの拡大断面図を表す。6 is an enlarged cross-sectional view of the ridges and their surroundings of the balloon shown in FIG. 5 . 薬剤層を備えたバルーンの凸条周りの拡大断面図の他の一例を表す。13 shows another example of an enlarged cross-sectional view of the area around the convex ridge of a balloon having a drug layer. 薬剤層を備えたバルーンの凸条周りの拡大断面図の他の一例を表す。13 shows another example of an enlarged cross-sectional view of the area around the convex ridge of a balloon having a drug layer. 図５に示したバルーンを収縮させて折り畳んだ状態の長手方向の垂直断面図の一例を表す。FIG. 6 illustrates an example of a vertical cross-sectional view in the longitudinal direction of the balloon shown in FIG. 5 in a deflated and folded state. 図５に示したバルーンを収縮させて折り畳んだ状態の長手方向の垂直断面図の他の一例を表す。FIG. 6 shows another example of a vertical cross-sectional view in the longitudinal direction of the balloon shown in FIG. 5 in a deflated and folded state. バルーン表面に薬剤層を形成する方法の模式図を表す。1 shows a schematic diagram of a method for forming a drug layer on a balloon surface.
　以下、下記実施の形態に基づき本発明を具体的に説明するが、本発明はもとより下記実施の形態によって制限を受けるものではなく、前・後記の趣旨に適合し得る範囲で適当に変更を加えて実施することも勿論可能であり、それらはいずれも本発明の技術的範囲に包含される。なお、各図面において、便宜上、ハッチングや部材符号等を省略する場合もあるが、かかる場合、明細書や他の図面を参照するものとする。また、図面における種々部材の寸法は、本発明の特徴の理解に資することを優先しているため、実際の寸法とは異なる場合がある。 The present invention will be described in detail below based on the following embodiment, but the present invention is of course not limited to the following embodiment, and can of course be implemented with appropriate modifications within the scope of the intent described above and below, all of which are included in the technical scope of the present invention. In addition, hatching and component symbols may be omitted in each drawing for convenience, but in such cases, reference should be made to the specification or other drawings. Furthermore, the dimensions of various components in the drawings may differ from the actual dimensions, as priority is given to contributing to an understanding of the features of the present invention.
　本発明の実施の形態に係るバルーンカテーテル用バルーンと、当該バルーンを備えたバルーンカテーテルの構成例について、図面を参照して説明する。図１～図４には、拡張状態のバルーンであって、バルーンの薬剤層を除いたバルーンカテーテルの構成例を示した。図１は、バルーンカテーテルの側面図を表し、図２は、図１に示したバルーンカテーテルに備えられたバルーンの斜視図を表し、図３は、図１に示したバルーンカテーテルのＩＩＩ－ＩＩＩ断面図を表し、図４は、図１に示したバルーンカテーテルのＩＶ－ＩＶ断面図を表す。図１にはラピッドエクスチェンジ型のバルーンカテーテルの構成例が示されている。 A balloon for a balloon catheter according to an embodiment of the present invention and an example of the configuration of a balloon catheter equipped with the balloon will be described with reference to the drawings. Figs. 1 to 4 show an example of the configuration of a balloon catheter in an expanded state, with the drug layer of the balloon removed. Fig. 1 shows a side view of the balloon catheter, Fig. 2 shows a perspective view of the balloon equipped in the balloon catheter shown in Fig. 1, Fig. 3 shows a III-III cross-sectional view of the balloon catheter shown in Fig. 1, and Fig. 4 shows an IV-IV cross-sectional view of the balloon catheter shown in Fig. 1. Fig. 1 shows an example of the configuration of a rapid exchange type balloon catheter.
　バルーンカテーテル１は、シャフト２と、シャフト２の外側に設けられたバルーン１０とを有する。バルーンカテーテル１は近位側と遠位側を有し、シャフト２の遠位部にバルーン１０が設けられる。バルーンカテーテル１の近位側とは、バルーンカテーテル１の延在方向に対して使用者（術者）の手元側の方向を指し、遠位側とは近位側の反対方向、すなわち処置対象側の方向を指す。また、バルーンカテーテル１の近位側から遠位側への方向を長手方向と称する。 The balloon catheter 1 has a shaft 2 and a balloon 10 provided on the outside of the shaft 2. The balloon catheter 1 has a proximal side and a distal side, and the balloon 10 is provided on the distal part of the shaft 2. The proximal side of the balloon catheter 1 refers to the direction toward the user's (operator's) hand in the extension direction of the balloon catheter 1, and the distal side refers to the opposite direction of the proximal side, i.e., the direction toward the treatment target. The direction from the proximal side to the distal side of the balloon catheter 1 is referred to as the longitudinal direction.
　バルーンカテーテル１は、シャフト２を通じてバルーン１０の内部に流体が供給されるように構成され、インデフレーター（バルーン用加減圧器）を用いてバルーン１０の拡張および収縮を制御することができる。流体は、ポンプ等により加圧された加圧流体であってもよい。以下、バルーン１０の内部に供給される流体を「バルーン拡張流体」と称する。 The balloon catheter 1 is configured so that fluid is supplied to the inside of the balloon 10 through the shaft 2, and the expansion and contraction of the balloon 10 can be controlled using an indeflator (a balloon pressurizer/depressurizer). The fluid may be a pressurized fluid pressurized by a pump or the like. Hereinafter, the fluid supplied to the inside of the balloon 10 is referred to as the "balloon expansion fluid."
　シャフト２は、例えば、インナーシャフト３とアウターシャフト４とから構成される。インナーシャフト３はアウターシャフト４の内腔に配置される。インナーシャフト３はシャフト２の進行をガイドするガイドワイヤの挿通路として機能させることができ、バルーンカテーテル１の使用の際、インナーシャフト３の内腔にガイドワイヤが挿通される。インナーシャフト３とアウターシャフト４の間の空間は、バルーン拡張流体の流路として機能させることができる。 The shaft 2 is composed of, for example, an inner shaft 3 and an outer shaft 4. The inner shaft 3 is disposed in the inner cavity of the outer shaft 4. The inner shaft 3 can function as a passage for a guide wire that guides the progress of the shaft 2, and when the balloon catheter 1 is used, the guide wire is inserted into the inner cavity of the inner shaft 3. The space between the inner shaft 3 and the outer shaft 4 can function as a flow path for the balloon expansion fluid.
　ラピッドエクスチェンジ型のバルーンカテーテル１では、シャフト２の遠位側から近位側に至る途中にガイドワイヤポート７が設けられ、インナーシャフト３の近位端がガイドワイヤポート７に接続し、インナーシャフト３の遠位端がシャフト２の遠位部まで延在することにより、ガイドワイヤポート７からシャフト２の遠位部まで延在するガイドワイヤ挿通路が形成される。 In the rapid exchange type balloon catheter 1, a guidewire port 7 is provided midway from the distal to the proximal side of the shaft 2, and the proximal end of the inner shaft 3 is connected to the guidewire port 7, and the distal end of the inner shaft 3 extends to the distal part of the shaft 2, forming a guidewire insertion passage that extends from the guidewire port 7 to the distal part of the shaft 2.
　アウターシャフト４は近位側アウターシャフト４Ａと遠位側アウターシャフト４Ｂを有していてもよく、この場合、遠位側アウターシャフト４Ｂの内腔にインナーシャフト３が配置されることが好ましい。近位側アウターシャフト４Ａと遠位側アウターシャフト４Ｂは同じ材料から構成されていてもよく、互いに異なる材料から構成されていてもよい。例えば、近位側アウターシャフト４Ａは樹脂または金属から構成され、遠位側アウターシャフト４Ｂは樹脂から構成されることが好ましい。なお、アウターシャフト４は近位側アウターシャフト４Ａと遠位側アウターシャフト４Ｂに区分されず、１つの部材から構成されていてもよく、近位側アウターシャフト４Ａと遠位側アウターシャフト４Ｂがさらに複数のチューブ部材から構成されていてもよい。 The outer shaft 4 may have a proximal outer shaft 4A and a distal outer shaft 4B, in which case it is preferable that the inner shaft 3 is disposed in the lumen of the distal outer shaft 4B. The proximal outer shaft 4A and the distal outer shaft 4B may be made of the same material, or may be made of different materials. For example, it is preferable that the proximal outer shaft 4A is made of resin or metal, and the distal outer shaft 4B is made of resin. Note that the outer shaft 4 may not be divided into the proximal outer shaft 4A and the distal outer shaft 4B, but may be made of a single member, or the proximal outer shaft 4A and the distal outer shaft 4B may be further made of multiple tube members.
　シャフト２の近位側にはハブ５が設けられることが好ましい。ハブ５は、シャフト２のバルーン拡張流体の流路と連通した流体注入部６を有することが好ましい。バルーン１０、シャフト２（インナーシャフト３、アウターシャフト４）、ハブ５の接合は、接着剤や熱溶着など従来公知の接合手段を用いて行うことができる。 A hub 5 is preferably provided on the proximal side of the shaft 2. The hub 5 preferably has a fluid injection section 6 that is connected to the flow path of the balloon expansion fluid in the shaft 2. The balloon 10, shaft 2 (inner shaft 3, outer shaft 4), and hub 5 can be joined using conventional joining means such as adhesives or heat welding.
　なお、図面に示されていないが、バルーンカテーテルは、インナーシャフトがシャフトの遠位部から近位部まで延び、シャフトの遠位側から近位側にわたってガイドワイヤの挿通路が形成されたオーバーザワイヤ型のバルーンカテーテルであってもよい。この場合、シャフトに設けられたバルーン拡張流体の流路とガイドワイヤの挿通路がハブまで延在し、ハブは、バルーン拡張流体の流路と連通した流体注入部と、ガイドワイヤの挿通路と連通した処置部とを有するように構成されることが好ましい。ハブは二又に分岐した構造を有し、二又に分岐した一方に流体注入部が設けられ、他方に処置部が設けられることが好ましい。 Although not shown in the drawings, the balloon catheter may be an over-the-wire type balloon catheter in which the inner shaft extends from the distal to the proximal part of the shaft and a guidewire passage is formed from the distal to the proximal side of the shaft. In this case, it is preferable that the flow path of the balloon expansion fluid and the guidewire passage provided in the shaft extend to the hub, and that the hub is configured to have a fluid injection section communicating with the flow path of the balloon expansion fluid and a treatment section communicating with the guidewire passage. It is preferable that the hub has a bifurcated structure, with the fluid injection section provided on one side of the bifurcated branch and the treatment section provided on the other side.
　シャフト２の外面はコーティングが施されていることが好ましい。ラピッドエクスチェンジ型のバルーンカテーテル１では、近位側アウターシャフト４Ａと遠位側アウターシャフト４Ｂの一方または両方の外面にコーティングが施されていることが好ましく、近位側アウターシャフト４Ａと遠位側アウターシャフト４Ｂの両方の外面にコーティングが施されていることがより好ましい。オーバーザワイヤ型のバルーンカテーテルでは、アウターシャフトの外面に適宜コーティングが施されていることが好ましい。 The outer surface of the shaft 2 is preferably coated. In a rapid exchange type balloon catheter 1, it is preferable that the outer surface of one or both of the proximal outer shaft 4A and the distal outer shaft 4B is coated, and it is more preferable that the outer surfaces of both the proximal outer shaft 4A and the distal outer shaft 4B are coated. In an over-the-wire type balloon catheter, it is preferable that the outer surface of the outer shaft is appropriately coated.
　コーティングは、目的に応じて親水性コーティングまたは疎水性コーティングとすることができる。シャフト２を親水性コーティング剤または疎水性コーティング剤に浸漬したり、シャフト２の外面に親水性コーティング剤または疎水性コーティング剤を塗布したり、シャフト２の外面を親水性コーティング剤または疎水性コーティング剤で被覆したりすることにより、シャフト２の外面にコーティングを施すことができる。コーティング剤は、薬剤や添加剤を含んでいてもよい。 The coating can be a hydrophilic coating or a hydrophobic coating depending on the purpose. The outer surface of the shaft 2 can be coated by immersing the shaft 2 in a hydrophilic or hydrophobic coating agent, applying a hydrophilic or hydrophobic coating agent to the outer surface of the shaft 2, or covering the outer surface of the shaft 2 with a hydrophilic or hydrophobic coating agent. The coating agent may contain drugs or additives.
　親水性コーティング剤としては、ポリビニルアルコール、ポリエチレングリコール、ポリアクリルアミド、ポリビニルピロリドン、メチルビニルエーテル無水マレイン酸共重合体などの親水性ポリマーや、これらの任意の組み合わせで作られた親水性コーティング剤等が挙げられる。 Hydrophilic coating agents include hydrophilic polymers such as polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyvinylpyrrolidone, and methyl vinyl ether maleic anhydride copolymers, as well as hydrophilic coating agents made from any combination of these.
　疎水性コーティング剤としては、ポリテトラフルオロエチレン（ＰＴＦＥ）、フッ化エチレンプロピレン（ＦＥＰ）、パーフルオロアルコキシアルカン（ＰＦＡ）、シリコーンオイル、疎水性ウレタン樹脂、カーボンコート、ダイヤモンドコート、ダイヤモンドライクカーボン（ＤＬＣ）コート、セラミックコート、アルキル基やパーフルオロアルキル基で終端された表面自由エネルギーが小さい物質等が挙げられる。 Hydrophobic coating agents include polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), perfluoroalkoxyalkane (PFA), silicone oil, hydrophobic urethane resin, carbon coat, diamond coat, diamond-like carbon (DLC) coat, ceramic coat, and substances with low surface free energy terminated with alkyl groups or perfluoroalkyl groups.
　バルーンカテーテル１の遠位端部には先端チップ８が設けられていることが好ましい。先端チップ８は、インナーシャフト３の遠位端よりも遠位側にインナーシャフト３とは別部材として設けられてもよく、インナーシャフト３がバルーン１０の遠位端よりも遠位側まで延在することにより、インナーシャフト３の遠位端部が先端チップ８として機能してもよい。 It is preferable that a tip tip 8 is provided at the distal end of the balloon catheter 1. The tip tip 8 may be provided as a separate member from the inner shaft 3, distal to the distal end of the inner shaft 3, or the inner shaft 3 may extend distal to the distal end of the balloon 10, so that the distal end of the inner shaft 3 functions as the tip tip 8.
　シャフト２には、バルーン１０の位置をＸ線透視下で確認することを可能にするために、長手方向に対してバルーン１０が位置する部分にＸ線不透過マーカー９が配置されていてもよい。Ｘ線不透過マーカー９は、例えば、バルーン１０の内部に配置されたインナーシャフト３上に配置することができ、バルーン１０の直管部の両端に相当する位置に配されることが好ましく、バルーン１０の直管部の中央に相当する位置に配されてもよい。 The shaft 2 may have an X-ray opaque marker 9 disposed at the portion where the balloon 10 is located in the longitudinal direction, so that the position of the balloon 10 can be confirmed under X-ray fluoroscopy. The X-ray opaque marker 9 may be disposed, for example, on the inner shaft 3 disposed inside the balloon 10, and is preferably disposed at positions corresponding to both ends of the straight tube portion of the balloon 10, or may be disposed at a position corresponding to the center of the straight tube portion of the balloon 10.
　バルーン１０は、長手方向と径方向を有し、近位側と遠位側に開口を有する筒状に形成されている（図２を参照）。バルーン１０の径方向とは、長手方向に垂直な方向であって、バルーン１０の中心から放射方向に向かって延びる方向を意味する。バルーン１０はまた、バルーン１０の長手方向の垂直断面において、拡張状態のバルーン１０の外周に沿った方向として、周方向を有する。 The balloon 10 has a longitudinal direction and a radial direction, and is formed into a cylindrical shape with openings on the proximal and distal sides (see FIG. 2). The radial direction of the balloon 10 means a direction perpendicular to the longitudinal direction, extending radially from the center of the balloon 10. The balloon 10 also has a circumferential direction, which is the direction along the outer periphery of the balloon 10 in an expanded state in a vertical cross section of the longitudinal direction of the balloon 10.
　バルーン１０は、長手方向に対して、直管部１３と、直管部１３よりも近位側に位置する近位側テーパー部１２と、直管部１３よりも遠位側に位置する遠位側テーパー部１４とを有する。バルーン１０の拡張状態で、直管部１３は長手方向に延びる略円筒形に形成され、バルーン１０において径方向の長さ（外径）が最も大きく形成される。近位側テーパー部１２は直管部１３の近位側に位置し、直管部１３の近位端に接続する。近位側テーパー部１２は、直管部１３から離れるに従って外径が小さくなるように形成されている。遠位側テーパー部１４は直管部１３の遠位側に位置し、直管部１３の遠位端に接続する。遠位側テーパー部１４は、直管部１３から離れるに従って外径が小さくなるように形成されている。バルーン１０はさらに、近位側テーパー部１２よりも近位側に位置する近位側スリーブ部１１と、遠位側テーパー部１４よりも遠位側に位置する遠位側スリーブ部１５を有することが好ましい。近位側スリーブ部１１は近位側テーパー部１２の近位側に位置し、近位側スリーブ部１１の近位端に接続する。近位側スリーブ部１１は略円筒形に形成されている。遠位側スリーブ部１５は遠位側テーパー部１４の遠位側に位置し、遠位側スリーブ部１５の遠位端に接続する。遠位側スリーブ部１５は略円筒形に形成されている。 The balloon 10 has a straight tube section 13, a proximal taper section 12 located proximal to the straight tube section 13, and a distal taper section 14 located distal to the straight tube section 13 in the longitudinal direction. When the balloon 10 is in an expanded state, the straight tube section 13 is formed in an approximately cylindrical shape extending in the longitudinal direction, and is formed to have the largest radial length (outer diameter) in the balloon 10. The proximal taper section 12 is located proximal to the straight tube section 13 and connects to the proximal end of the straight tube section 13. The proximal taper section 12 is formed so that the outer diameter decreases with increasing distance from the straight tube section 13. The distal taper section 14 is located distal to the straight tube section 13 and connects to the distal end of the straight tube section 13. The distal taper section 14 is formed so that the outer diameter decreases with increasing distance from the straight tube section 13. The balloon 10 preferably further has a proximal sleeve portion 11 located proximal to the proximal taper portion 12 and a distal sleeve portion 15 located distal to the distal taper portion 14. The proximal sleeve portion 11 is located proximal to the proximal taper portion 12 and is connected to the proximal end of the proximal sleeve portion 11. The proximal sleeve portion 11 is formed in a substantially cylindrical shape. The distal sleeve portion 15 is located distal to the distal taper portion 14 and is connected to the distal end of the distal sleeve portion 15. The distal sleeve portion 15 is formed in a substantially cylindrical shape.
　上記のようにバルーン１０が構成されることにより、バルーン１０を狭窄部において拡張させた際に直管部１３が狭窄部に十分に接触して、狭窄部の拡張等の治療を行いやすくなる。また、バルーン１０が近位側テーパー部１２と遠位側テーパー部１４を有することにより、バルーン１０を収縮させた際にバルーン１０の近位端部と遠位端部の外径を小さくしてシャフト２とバルーン１０との段差を小さくすることができ、バルーン１０を体腔内や内視鏡の鉗子チャネル内を挿通しやすくすることができる。 By configuring the balloon 10 as described above, when the balloon 10 is expanded at the narrowed area, the straight tube section 13 comes into sufficient contact with the narrowed area, making it easier to perform treatment such as expanding the narrowed area. In addition, since the balloon 10 has a proximal tapered section 12 and a distal tapered section 14, when the balloon 10 is deflated, the outer diameter of the proximal and distal ends of the balloon 10 can be reduced to reduce the step between the shaft 2 and the balloon 10, making it easier to insert the balloon 10 into a body cavity or a forceps channel of an endoscope.
　シャフト２の遠位部において、インナーシャフト３がアウターシャフト４の遠位端から遠位側に延出し、インナーシャフト３がバルーン１０の内部空間を近位側スリーブ部１１から遠位側スリーブ部１５にかけて延在することが好ましい。そして、インナーシャフト３の外面がバルーン１０の遠位側スリーブ部１５の内面に接合し、アウターシャフト４の外面がバルーン１０の近位側スリーブ部１１の内面に接合することが好ましい。このようにシャフト２の遠位部が構成されることにより、バルーン拡張流体を、インナーシャフト３とアウターシャフト４の間の空間を通ってバルーン１０の内部空間に供給することができる。 In the distal portion of the shaft 2, it is preferable that the inner shaft 3 extends distally from the distal end of the outer shaft 4, and that the inner shaft 3 extends through the internal space of the balloon 10 from the proximal sleeve portion 11 to the distal sleeve portion 15. It is also preferable that the outer surface of the inner shaft 3 is joined to the internal surface of the distal sleeve portion 15 of the balloon 10, and the outer surface of the outer shaft 4 is joined to the internal surface of the proximal sleeve portion 11 of the balloon 10. By configuring the distal portion of the shaft 2 in this manner, it is possible to supply balloon expansion fluid to the internal space of the balloon 10 through the space between the inner shaft 3 and the outer shaft 4.
　バルーン１０は樹脂から構成されることが好ましく、より好ましくは熱可塑性樹脂から構成される。これにより、成型によりバルーン１０を製造することが容易になる。バルーン１０を構成する樹脂としては、例えば、ポリエチレン、ポリプロピレン、エチレン－プロピレン共重合体等のポリオレフィン樹脂、ポリエチレンテレフタレート、ポリエステルエラストマー等のポリエステル樹脂、ポリウレタン、ポリウレタンエラストマー等のポリウレタン樹脂、ポリフェニレンサルファイド樹脂、ポリアミド、ポリアミドエラストマー等のポリアミド樹脂、フッ素系樹脂、シリコーン樹脂、ラテックスゴム等の天然ゴム等が挙げられる。これらは１種のみを用いてもよく、２種以上を併用してもよい。なかでも、ポリアミド樹脂、ポリエステル樹脂、ポリウレタン樹脂が好適に用いられる。特に、バルーン１０の薄膜化や柔軟性の点から、エラストマー樹脂を用いることが好ましい。例えばポリアミド樹脂の中でバルーン１０に好適な材料として、ナイロン１２、ナイロン１１等が挙げられ、ブロー成形する際に比較的容易に成形可能である点から、ナイロン１２が好適に用いられる。また、バルーン１０の薄膜化や柔軟性の点から、ポリエーテルエステルアミドエラストマー、ポリアミドエーテルエラストマー等のポリアミドエラストマーが好ましく用いられる。なかでも、降伏強度が高く、バルーン１０の寸法安定性が良好な点から、ポリエーテルエステルアミドエラストマーが好ましく用いられる。 The balloon 10 is preferably made of a resin, more preferably a thermoplastic resin. This makes it easier to manufacture the balloon 10 by molding. Examples of resins that make up the balloon 10 include polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymer, polyester resins such as polyethylene terephthalate and polyester elastomer, polyurethane resins such as polyurethane and polyurethane elastomer, polyphenylene sulfide resins, polyamide resins such as polyamide and polyamide elastomer, fluorine-based resins, silicone resins, and natural rubbers such as latex rubber. These may be used alone or in combination of two or more. Among these, polyamide resins, polyester resins, and polyurethane resins are preferably used. In particular, elastomer resins are preferably used in terms of thinning and flexibility of the balloon 10. For example, nylon 12 and nylon 11 are examples of polyamide resins that are suitable for the balloon 10, and nylon 12 is preferably used because it is relatively easy to mold when blow molding. In addition, polyamide elastomers such as polyether ester amide elastomers and polyamide ether elastomers are preferably used in terms of thinning and flexibility of the balloon 10. Among these, polyether ester amide elastomers are preferably used because they have high yield strength and provide good dimensional stability to the balloon 10.
　バルーン１０は、直管部１３の外面に凸条１７を有する。直管部１３の外面に凸条１７が設けられることにより、バルーン１０はスコアリング機能を有するものとなり、バルーン１０を血管の狭窄部において拡張させた際に、石灰化した狭窄部に食い込んで、狭窄部に亀裂を入れたりすることが可能となる。そのため、血管内膜の解離を抑えながら狭窄部を拡張させることができる。また、バルーン１０の高強度化や加圧時の過拡張の抑制も可能となる。なお、バルーン１０は、血管以外の体腔の狭窄部や病変部の治療に用いることもできるが、以下では血管の狭窄部においてバルーン１０を適用する場合を例にとって説明する。 The balloon 10 has a ridge 17 on the outer surface of the straight tube section 13. The ridge 17 on the outer surface of the straight tube section 13 gives the balloon 10 a scoring function, and when the balloon 10 is expanded at a narrowed portion of a blood vessel, it can bite into the calcified narrowed portion and create a crack in the narrowed portion. This allows the narrowed portion to be expanded while suppressing dissection of the vascular intima. It also makes it possible to increase the strength of the balloon 10 and suppress overexpansion when pressurized. The balloon 10 can also be used to treat narrowed portions or lesions in body cavities other than blood vessels, but the following description will be given taking as an example a case in which the balloon 10 is applied to a narrowed portion of a blood vessel.
　バルーン１０の凸条１７について、図５～図８を参照して詳しく説明する。図５には、バルーン１０の直管部１３の長手方向の垂直断面図が示され、図６～図８には、バルーン１０の凸条１７周りの拡大断面図が示されている。図５～図８では、直管部１３の外面に薬剤層３１が設けられたバルーン１０が示されている。図５には、図２および図４に示したバルーン１０の外面に薬剤層３１が設けられた構成例が示されており、凸条１７が直管部１３の周方向の３箇所に設けられている。 The ridges 17 of the balloon 10 will be described in detail with reference to Figures 5 to 8. Figure 5 shows a vertical cross-section in the longitudinal direction of the straight tube section 13 of the balloon 10, and Figures 6 to 8 show enlarged cross-sections of the ridges 17 and the surrounding area of the balloon 10. Figures 5 to 8 show a balloon 10 in which a drug layer 31 is provided on the outer surface of the straight tube section 13. Figure 5 shows an example configuration in which a drug layer 31 is provided on the outer surface of the balloon 10 shown in Figures 2 and 4, and the ridges 17 are provided at three locations in the circumferential direction of the straight tube section 13.
　バルーン１０の直管部１３は、筒形状のバルーン本体部１６を有し、バルーン本体部１６の外面に凸条１７が設けられる。凸条１７は、バルーン本体部１６の外面から径方向の外方に突出するように設けられる。バルーン１０は、凸条１７が設けられることにより、直管部１３の外面に凸条存在領域２１と凸条非存在領域２２が形成される。 The straight tube section 13 of the balloon 10 has a cylindrical balloon main body section 16, and a convex rib 17 is provided on the outer surface of the balloon main body section 16. The convex rib 17 is provided so as to protrude radially outward from the outer surface of the balloon main body section 16. By providing the convex rib 17, the balloon 10 has a convex rib region 21 and a convex rib non-existent region 22 formed on the outer surface of the straight tube section 13.
　凸条１７は、頂部１７Ａと基部１７Ｂを有する（図６～図８を参照）。凸条１７において、頂部１７Ａは凸条１７の先端、すなわち凸条１７の径方向の最も外方に位置する部分を意味し、基部１７Ｂは、凸条１７の側面１８において、バルーン本体部１６との境界、すなわち凸条１７の径方向の最も内方に位置する部分を意味する。 The ridge 17 has an apex 17A and a base 17B (see Figures 6 to 8). In the ridge 17, the apex 17A refers to the tip of the ridge 17, i.e., the part located radially outward of the ridge 17, and the base 17B refers to the boundary between the side surface 18 of the ridge 17 and the balloon body 16, i.e., the part located radially inward of the ridge 17.
　凸条１７は、例えば樹脂から構成することができる。凸条１７が樹脂から構成されていれば、凸条１７を有するバルーン１０を樹脂成型により製造することができ、製造が容易になる。この場合、凸条１７とバルーン本体部１６は同じ樹脂から構成されることが好ましく、凸条１７とバルーン本体部１６とが一体形成されていることが好ましい。バルーン本体部１６は内層と外層を有していてもよく、この場合、凸条１７はバルーン本体部１６の外層と同じ樹脂から構成されていることが好ましい。これにより、凸条１７が意図せずバルーン本体部１６から脱落することが起こりにくくなる。あるいは、凸条１７を構成する樹脂とバルーン本体部１６を構成する樹脂とがある程度の相溶性があれば、凸条１７とバルーン本体部１６は互いに異なる樹脂から構成されていてもよい。 The ridges 17 can be made of resin, for example. If the ridges 17 are made of resin, the balloon 10 having the ridges 17 can be manufactured by resin molding, making manufacturing easier. In this case, the ridges 17 and the balloon body 16 are preferably made of the same resin, and the ridges 17 and the balloon body 16 are preferably integrally formed. The balloon body 16 may have an inner layer and an outer layer, and in this case, the ridges 17 are preferably made of the same resin as the outer layer of the balloon body 16. This makes it less likely that the ridges 17 will unintentionally fall off the balloon body 16. Alternatively, the ridges 17 and the balloon body 16 may be made of different resins, as long as there is a certain degree of compatibility between the resin that makes up the ridges 17 and the resin that makes up the balloon body 16.
　凸条１７は金属から構成されてもよく、あるいは金属と樹脂の組み合わせから構成されてもよい。この場合、凸条１７の頂部１７Ａを含む部分が金属から構成されることが好ましい。これにより、バルーン１０を拡張させた際に、凸条１７によって狭窄部に亀裂を入れたり、狭窄部を切開することが容易になる。例えば、凸条１７の全体が金属から構成されてもよく、凸条１７の基部１７Ｂを含む部分が樹脂から構成され、凸条１７の頂部１７Ａを含む部分が金属から構成されてもよい。従って、凸条１７は、樹脂製、金属製、またはその組み合わせであることが好ましい。 The ridges 17 may be made of metal, or a combination of metal and resin. In this case, it is preferable that the portion including the apex 17A of the ridges 17 is made of metal. This makes it easier for the ridges 17 to create a crack in the narrowed area or to cut open the narrowed area when the balloon 10 is inflated. For example, the entire ridges 17 may be made of metal, or the portion including the base 17B of the ridges 17 may be made of resin, and the portion including the apex 17A of the ridges 17 may be made of metal. Therefore, it is preferable that the ridges 17 are made of resin, metal, or a combination thereof.
　直管部１３において、バルーン本体部１６は筒形状を有する部分として規定される。直管部１３において径方向の外方に突出した凸条１７を除いた部分がバルーン本体部１６となる。バルーン本体部１６は外面が円筒形に形成されていると見なすことができる。従って、直管部１３の長手方向の垂直断面において、バルーン本体部１６の外形は実質的に円形に形成され、これによりバルーン本体部１６と凸条１７とを区分することができる。図７～図１０では、バルーン本体部１６と凸条１７とが点線で区分されて示されている。凸条存在領域２１はバルーン本体部１６と凸条１７とから構成され、凸条非存在領域２２はバルーン本体部１６から構成される。 In the straight pipe section 13, the balloon main body 16 is defined as a portion having a cylindrical shape. The straight pipe section 13 is composed of the balloon main body 16 excluding the ridges 17 protruding radially outward. The outer surface of the balloon main body 16 can be considered to be formed in a cylindrical shape. Therefore, in a vertical cross section in the longitudinal direction of the straight pipe section 13, the outer shape of the balloon main body 16 is formed in a substantially circular shape, which allows the balloon main body 16 and the ridges 17 to be distinguished from each other. In Figures 7 to 10, the balloon main body 16 and the ridges 17 are shown separated by dotted lines. The ridge-present region 21 is composed of the balloon main body 16 and the ridges 17, and the ridge-free region 22 is composed of the balloon main body 16.
　凸条１７は、直管部１３の外面において、畝状に延びるように設けられる。凸条１７は、長手方向に延びるように設けられることが好ましく、この場合、凸条１７は、バルーン１０の長手方向に略平行に延びるものであってもよく、長手方向にらせん状に延びるものであってもよい。なお、バルーン１０のスコアリング機能を高め、また凸条１７を有するバルーン１０の製造が容易な点から、凸条１７はバルーン１０の長手方向に略平行に延びていることが好ましい。 The convex ribs 17 are provided on the outer surface of the straight tube section 13 so as to extend in a ridge-like manner. It is preferable that the convex ribs 17 are provided so as to extend in the longitudinal direction. In this case, the convex ribs 17 may extend approximately parallel to the longitudinal direction of the balloon 10, or may extend in a spiral shape in the longitudinal direction. Note that it is preferable that the convex ribs 17 extend approximately parallel to the longitudinal direction of the balloon 10, in order to enhance the scoring function of the balloon 10 and to facilitate the manufacture of a balloon 10 having the convex ribs 17.
　凸条１７は、直管部１３の長手方向の垂直断面において、１つのみ設けられてもよく、複数設けられてもよい。直管部１３に凸条１７が１つのみ設けられる場合は、直管部１３に凸条非存在領域２２が１つのみ形成され、直管部１３に凸条１７が複数設けられる場合は、直管部１３に凸条非存在領域２２が複数形成される。凸条非存在領域２２は、凸条１７と等しい数だけ形成される。図５では、凸条１７は、バルーン１０の直管部１３の周方向の３箇所に設けられている。 Only one or more convex ribs 17 may be provided in a vertical cross section in the longitudinal direction of the straight pipe section 13. When only one convex rib 17 is provided in the straight pipe section 13, only one non-convex rib region 22 is formed in the straight pipe section 13, and when multiple convex ribs 17 are provided in the straight pipe section 13, multiple non-convex rib regions 22 are formed in the straight pipe section 13. The non-convex rib regions 22 are formed in the same number as the convex ribs 17. In FIG. 5, the convex ribs 17 are provided in three locations in the circumferential direction of the straight pipe section 13 of the balloon 10.
　凸条１７は、バルーン１０の直管部１３において、周方向の異なる位置に複数設けられることが好ましい。すなわち凸条１７は、バルーン１０の周方向の複数箇所に設けられることが好ましい。この場合、凸条１７は、バルーン１０の直管部１３の周方向に略等間隔に配置されることが好ましい。これにより、バルーン１０を拡張させた際に、狭窄部の複数の箇所に亀裂を入れることが可能となる。凸条１７は、バルーン１０の周方向に対して２箇所以上の位置に設けられることが好ましく、３箇所以上がより好ましく、また８箇所以下が好ましく、６箇所以下がより好ましい。また、この場合の凸条１７の周方向の間隔は、１つの凸条１７の周方向の長さよりも長いことが好ましい。 The ridges 17 are preferably provided at multiple different circumferential positions on the straight tube section 13 of the balloon 10. That is, the ridges 17 are preferably provided at multiple locations on the balloon 10 in the circumferential direction. In this case, the ridges 17 are preferably arranged at approximately equal intervals on the straight tube section 13 of the balloon 10 in the circumferential direction. This makes it possible to create cracks in multiple locations on the narrowed section when the balloon 10 is expanded. The ridges 17 are preferably provided at two or more locations on the circumferential direction of the balloon 10, more preferably three or more locations, and preferably eight or fewer locations, and more preferably six or fewer locations. In this case, the circumferential interval of the ridges 17 is preferably longer than the circumferential length of one ridge 17.
　凸条１７の断面形状は特に限定されない。例えば、直管部１３の長手方向の垂直断面における凸条１７の形状としては、三角形、四角形等の多角形、半円形、扇形等の円形の部分形状、略円形、楔型、凸形、紡錘形、不定形等が挙げられる。多角形には、角部の頂点が明確であって辺が直線であるものの他に、角部が丸みを帯びている角丸多角形や、辺の少なくとも一部が曲線となっているものも含まれる。なお、凸条１７は、頂部１７Ａに向かって幅狭になるように形成されていることが好ましい。 The cross-sectional shape of the convex ribs 17 is not particularly limited. For example, the shape of the convex ribs 17 in a vertical cross section in the longitudinal direction of the straight pipe section 13 may be a polygon such as a triangle or a rectangle, a partial shape of a circle such as a semicircle or a sector, an approximately circular shape, a wedge shape, a convex shape, a spindle shape, an irregular shape, etc. Polygons include polygons with clear corner apexes and straight sides, as well as rounded polygons with rounded corners and polygons with at least some of the sides curved. It is preferable that the convex ribs 17 are formed so that they narrow toward the apex 17A.
　図６～図８には、凸条１７の様々な断面形状の例が示されている。図６では、凸条１７は頂部１７Ａに向かって無段状に幅が狭まるように形成されている。図７では、凸条１７は頂部１７Ａに向かって段状に幅が狭まるように形成されている。図８では、凸条１７は、頂部１７Ａに向かって幅が広がる部分と幅が狭まる部分を有するように形成される。図６～図８に示した凸条１７の各形態の詳細については、後述する。 Figures 6 to 8 show examples of various cross-sectional shapes of the convex ribs 17. In Figure 6, the convex ribs 17 are formed so that their width narrows steplessly toward the apex 17A. In Figure 7, the convex ribs 17 are formed so that their width narrows stepwise toward the apex 17A. In Figure 8, the convex ribs 17 are formed so that they have a portion where their width widens and a portion where their width narrows toward the apex 17A. Details of each shape of the convex ribs 17 shown in Figures 6 to 8 will be described later.
　直管部１３の長手方向の垂直断面において、凸条１７の高さは凸条１７の幅（最大幅）の０．２倍以上であることが好ましい。このように凸条１７が形成されていれば、狭窄部においてバルーン１０を拡張させた際に、凸条１７が狭窄部に食い込みやすくなり、凸条１７によるスコアリング機能を高めることができる。また、後述するように、凸条１７の側面１８に薬剤層を形成することが容易になる。なお、ここで説明した凸条１７の幅は、凸条１７の周方向の長さを意味する。凸条１７は、基部１７Ｂにおいて最大幅となるように形成されていてもよく、これにより凸条１７がバルーン本体部１６の外面に安定して設置される。凸条１７の高さは凸条１７の幅の０．４倍以上がより好ましく、０．７倍以上がさらに好ましく、また２．０倍以下が好ましく、１．８倍以下がより好ましく、１．５倍以下がさらに好ましい。 In the vertical cross section of the straight tube portion 13 in the longitudinal direction, the height of the ridge 17 is preferably 0.2 times or more the width (maximum width) of the ridge 17. If the ridge 17 is formed in this manner, when the balloon 10 is expanded at the narrowed portion, the ridge 17 is more likely to bite into the narrowed portion, and the scoring function of the ridge 17 can be improved. In addition, as described below, it becomes easier to form a drug layer on the side surface 18 of the ridge 17. Note that the width of the ridge 17 described here means the circumferential length of the ridge 17. The ridge 17 may be formed so that it is at its widest at the base 17B, so that the ridge 17 is stably installed on the outer surface of the balloon body portion 16. The height of the ridge 17 is more preferably 0.4 times or more the width of the ridge 17, more preferably 0.7 times or more, and more preferably 2.0 times or less, more preferably 1.8 times or less, and even more preferably 1.5 times or less.
　直管部１３において、凸条１７が設けられた部分の肉厚、すなわち凸条存在領域２１の肉厚は、凸条１７が設けられない部分の肉厚、すなわち凸条非存在領域２２の肉厚よりも厚く形成されていることが好ましい。これにより、凸条１７によるスコアリング機能を高めることができる。凸条存在領域２１の肉厚（最大肉厚）は、凸条非存在領域２２の肉厚（最大肉厚）の１．５倍以上であることが好ましく、２．０倍以上がより好ましく、２．５倍以上がさらに好ましい。凸条存在領域２１の肉厚の上限は特に限定されず、例えば、凸条非存在領域２２の肉厚の３０倍以下、２０倍以下または１０倍以下であってもよい。 In the straight pipe section 13, the thickness of the portion where the ridges 17 are provided, i.e., the thickness of the ridge-present region 21, is preferably formed thicker than the thickness of the portion where the ridges 17 are not provided, i.e., the thickness of the ridge-free region 22. This can improve the scoring function of the ridges 17. The thickness (maximum thickness) of the ridge-present region 21 is preferably 1.5 times or more, more preferably 2.0 times or more, and even more preferably 2.5 times or more, the thickness (maximum thickness) of the ridge-free region 22. There is no particular limit to the upper limit of the thickness of the ridge-present region 21, and may be, for example, 30 times or less, 20 times or less, or 10 times or less, the thickness of the ridge-free region 22.
　バルーン１０において、凸条１７は、直管部１３の長手方向の１／２以上の範囲に設けられることが好ましく、２／３以上の範囲に設けられることがより好ましく、３／４以上の範囲に設けられることがさらに好ましい。これにより、バルーン１０を拡張させた際に、狭窄部の広い範囲に亀裂を入れることが可能となる。凸条１７は、近位側テーパー部１２および／または遠位側テーパー部１４の外面にも設けられてもよい。図１および図２では、凸条１７は、近位側テーパー部１２から直管部１３を経由して遠位側テーパー部１４まで延びるように設けられている。 In the balloon 10, the ridges 17 are preferably provided over at least 1/2 of the longitudinal length of the straight tube section 13, more preferably over at least 2/3 of the longitudinal length, and even more preferably over at least 3/4 of the longitudinal length. This allows cracks to be created over a wide range of the narrowed area when the balloon 10 is expanded. The ridges 17 may also be provided on the outer surface of the proximal taper section 12 and/or the distal taper section 14. In Figures 1 and 2, the ridges 17 are provided so as to extend from the proximal taper section 12 through the straight tube section 13 to the distal taper section 14.
　バルーン１０は、バルーン１０の内面において径方向の内方に向かって突出している内側凸条を有していてもよい（図示せず）。凸条１７と内側凸条はバルーン１０の長手方向や周方向に対して同じ位置に配置されていてもよく、これらは一体成形されていることが好ましく、これによりバルーン１０の一部が肉厚に形成されていてもよい。 The balloon 10 may have an inner ridge that protrudes radially inward on the inner surface of the balloon 10 (not shown). The ridge 17 and the inner ridge may be located at the same position in the longitudinal or circumferential direction of the balloon 10, and it is preferable that they are integrally molded, so that a portion of the balloon 10 may be formed thick.
　バルーン１０の直管部１３の外面には薬剤層３１が設けられている。薬剤層３１に含まれる薬剤は、薬理活性物質であれば特に限定されず、例えば、遺伝子治療薬、非遺伝子治療薬、小分子、細胞等の医薬として許容される薬剤が挙げられる。特に、バルーンカテーテル１を血管形成術における治療後の血管の再狭窄を抑制する目的で使用する場合は、薬剤として抗増殖剤や免疫抑制剤などの抗再狭窄剤を好ましく用いることができ、具体的には、パクリタキセル、シロリムス（ラパマイシン）、エベロリムス、ゾタロリムス等の薬剤を用いることができる。これらの薬剤は、１種のみを用いてもよく、２種以上を用いてもよい。 A drug layer 31 is provided on the outer surface of the straight tube portion 13 of the balloon 10. The drug contained in the drug layer 31 is not particularly limited as long as it is a pharmacologically active substance, and examples of such drugs include drugs that are acceptable as medicines, such as gene therapy drugs, non-gene therapy drugs, small molecules, and cells. In particular, when the balloon catheter 1 is used for the purpose of suppressing vascular restenosis after treatment in angioplasty, anti-restenosis drugs such as antiproliferative agents and immunosuppressants can be preferably used as the drug, and specifically, drugs such as paclitaxel, sirolimus (rapamycin), everolimus, and zotarolimus can be used. Only one type of these drugs may be used, or two or more types may be used.
　薬剤層３１には、薬理活性物質とともに、薬剤の分散性、溶解性、血管壁への移行性、保存安定性を向上させるための助剤が含まれていてもよい。助剤としては、安定化剤、結合剤、崩壊剤、防湿剤、防腐剤、溶解助剤などが用いられ、具体的には、乳糖、白糖、麦芽糖、デキストリン、キシリトール、エリスリトール、マンニトール、エチレンジアミン、ヨウ化カリウム、尿素、ポリソルベート、ジブチルヒドロキシトルエン、ポリエチレングリコール、脂質、ピロ亜硫酸ナトリウム、アスコルビン酸、トコフェロール、安息香酸、パラオキシ安息香酸エステル、ポリアクリル酸、ポリ乳酸、ポリグリコール酸、ヒアルロン酸、キトサン、ゼラチン等が挙げられる。 The drug layer 31 may contain, in addition to the pharmacologically active substance, auxiliary agents for improving the dispersibility, solubility, migration to the vascular wall, and storage stability of the drug. Examples of auxiliary agents that can be used include stabilizers, binders, disintegrants, moisture-proofing agents, preservatives, and dissolution aids. Specific examples include lactose, sucrose, maltose, dextrin, xylitol, erythritol, mannitol, ethylenediamine, potassium iodide, urea, polysorbate, dibutylhydroxytoluene, polyethylene glycol, lipids, sodium pyrosulfite, ascorbic acid, tocopherol, benzoic acid, paraoxybenzoic acid esters, polyacrylic acid, polylactic acid, polyglycolic acid, hyaluronic acid, chitosan, and gelatin.
　薬剤層３１は、狭窄部への送達中（デリバリー中）に薬剤が血液中に溶出したり脱落することを抑制するために、保護層を有していてもよい。保護層は薬剤層３１の一部に含まれ、薬剤層３１の最外層を構成することが好ましい。保護層は、例えば水溶性高分子から構成され、例えば、カルボキシルメチルセルロース、ヒドロキシプロピルセルロース、メチルセルロース、ヒドロキシエチルセルロース、ポリビニルアルコール、アルギン酸、ペクチン、アラビアガム、ジェランガム、グアガム、キサンタンガム、カラギーナン、ゼラチンなどから形成することができる。 The drug layer 31 may have a protective layer to prevent the drug from dissolving in the blood or falling off during delivery to the stenotic area. The protective layer is preferably included as part of the drug layer 31 and constitutes the outermost layer of the drug layer 31. The protective layer is composed of, for example, a water-soluble polymer, and can be formed from, for example, carboxymethylcellulose, hydroxypropylcellulose, methylcellulose, hydroxyethylcellulose, polyvinyl alcohol, alginic acid, pectin, gum arabic, gellan gum, guar gum, xanthan gum, carrageenan, gelatin, etc.
　薬剤層３１は、凸条１７の側面１８を含む直管部１３の外面に設けられており、直管部１３の長手方向の垂直断面において、２つある側面１８のうち一方の側面１８の基部１７Ｂにおける薬剤層３１が他方の側面１８の基部１７Ｂにおける薬剤層３１よりも厚く設けられている。具体的には、直管部１３の長手方向の垂直断面において、凸条１７の頂部１７Ａを通り径方向に延びる仮想直線１７Ｌに対して一方側にある側面１８を第１側面１８Ａとし、他方側にある側面１８を第２側面１８Ｂとしたとき、第１側面１８Ａの基部１７Ｂにおける薬剤層３１の厚みが、第２側面１８Ｂの基部１７Ｂにおける薬剤層３１の厚みよりも厚くなっている。このように薬剤層３１が設けられることにより、狭窄部においてバルーン１０を拡張させた際に、血管壁の内部に効率的に薬剤を移行させることができる。すなわち、狭窄部においてバルーン１０を拡張させた際に、凸条１７の第２側面１８Ｂにおいて狭窄部での食い込み性能が確保され、凸条１７の第１側面１８Ａにおいてより多くの薬剤が保持され、拡張させた狭窄部において血管壁の内面から内部にかけて薬剤を効率的に届けることができる。 The drug layer 31 is provided on the outer surface of the straight tube section 13 including the side surface 18 of the convex rib 17, and in a vertical cross section of the straight tube section 13 in the longitudinal direction, the drug layer 31 at the base 17B of one of the two side surfaces 18 is provided thicker than the drug layer 31 at the base 17B of the other side surface 18. Specifically, in a vertical cross section of the longitudinal direction of the straight tube section 13, when the side surface 18 on one side of the virtual straight line 17L that passes through the top 17A of the convex rib 17 and extends in the radial direction is defined as the first side surface 18A and the side surface 18 on the other side is defined as the second side surface 18B, the thickness of the drug layer 31 at the base 17B of the first side surface 18A is thicker than the thickness of the drug layer 31 at the base 17B of the second side surface 18B. By providing the drug layer 31 in this manner, when the balloon 10 is expanded at the stenosis, the drug can be efficiently transferred into the inside of the blood vessel wall. That is, when the balloon 10 is expanded at the narrowed area, the second side surface 18B of the ridge 17 ensures the ability to penetrate into the narrowed area, and the first side surface 18A of the ridge 17 holds more drug, allowing the drug to be efficiently delivered from the inner surface of the blood vessel wall to the inside of the expanded narrowed area.
　凸条１７の基部１７Ｂにおける薬剤層３１の厚みは、直管部１３の長手方向の垂直断面において、凸条１７の基部１７Ｂから薬剤層３１の表面までの最短長さ（図６～図８における矢印３２の長さ）を意味する。なお、薬剤層３１は乾燥状態によって表面に亀裂が生じることも想定されるが、そのような場合は、亀裂が生じた箇所を除いた薬剤層３１の表面までの最短長さを、凸条１７の基部１７Ｂにおける薬剤層３１の厚みとする。 The thickness of drug layer 31 at base 17B of ridge 17 means the shortest length from base 17B of ridge 17 to the surface of drug layer 31 in a vertical cross section in the longitudinal direction of straight tube section 13 (the length of arrow 32 in Figures 6 to 8). It is anticipated that cracks may develop on the surface of drug layer 31 due to the dry state. In such a case, the thickness of drug layer 31 at base 17B of ridge 17 is defined as the shortest length to the surface of drug layer 31 excluding the location where the cracks have developed.
　直管部１３の長手方向の垂直断面において凸条１７が複数設けられる場合は、複数の凸条１７のうちの少なくとも１つの凸条１７において、第１側面１８Ａの基部１７Ｂにおける薬剤層３１の厚みが第２側面１８Ｂの基部１７Ｂにおける薬剤層３１の厚みよりも厚くなっていればよい。好ましくは複数の凸条１７の全てにおいて、第１側面１８Ａの基部１７Ｂにおける薬剤層３１の厚みが第２側面１８Ｂの基部１７Ｂにおける薬剤層３１の厚みよりも厚く形成される。 When multiple ridges 17 are provided in a longitudinal vertical cross section of the straight tube section 13, it is sufficient that the thickness of the drug layer 31 at the base 17B of the first side surface 18A in at least one of the multiple ridges 17 is thicker than the thickness of the drug layer 31 at the base 17B of the second side surface 18B. Preferably, the thickness of the drug layer 31 at the base 17B of the first side surface 18A in all of the multiple ridges 17 is formed to be thicker than the thickness of the drug layer 31 at the base 17B of the second side surface 18B.
　凸条１７において第１側面１８Ａと第２側面１８Ｂの周方向の位置関係は特に限定されず、例えば、バルーン１０を遠位側から見て、凸条１７の左側の側面１８が第１側面１８Ａとなってもよく、右側の側面１８が第１側面１８Ａとなってもよい。なお、凸条１７が複数設けられる場合は、複数の凸条１７の全てにおいて、第１側面１８Ａと第２側面１８Ｂの周方向の位置関係が同じとなることが好ましく、バルーン１０を遠位側から見て、例えば凸条１７の右側の側面が第１側面１８Ａとなり左側の側面１８が第２側面１８Ｂとなる。 The circumferential positional relationship between the first side surface 18A and the second side surface 18B of the convex rib 17 is not particularly limited, and for example, when viewing the balloon 10 from the distal side, the left side surface 18 of the convex rib 17 may be the first side surface 18A, or the right side surface 18 may be the first side surface 18A. Note that when multiple convex ribs 17 are provided, it is preferable that the circumferential positional relationship between the first side surface 18A and the second side surface 18B is the same for all multiple convex ribs 17, and when viewing the balloon 10 from the distal side, for example, the right side surface of the convex rib 17 is the first side surface 18A and the left side surface 18 is the second side surface 18B.
　１つの凸条１７において、第１側面１８Ａの基部１７Ｂにおける薬剤層３１の厚みは第２側面１８Ｂの基部１７Ｂにおける薬剤層３１の厚みの１．２倍以上であることが好ましく、１．５倍以上がより好ましく、１．８倍以上がさらに好ましい。一方、第２側面１８Ｂの基部１７Ｂにおける薬剤層３１の厚みに対する第１側面１８Ａの基部１７Ｂにおける薬剤層３１の厚みの比の上限値は特に限定されず、第２側面１８Ｂの基部１７Ｂには薬剤層３１が存在しなくてもよく、あるいは非常に薄い厚みで存在してもよい。例えば、１つの凸条１７において、第１側面１８Ａの基部１７Ｂにおける薬剤層３１の厚みは第２側面１８Ｂの基部１７Ｂにおける薬剤層３１の厚みの１００倍以下であってもよく、５０倍以下、３０倍以下、２０倍以下または１０倍以下であってもよい。 In one convex streak 17, the thickness of the drug layer 31 at the base 17B of the first side 18A is preferably 1.2 times or more, more preferably 1.5 times or more, and even more preferably 1.8 times or more, of the thickness of the drug layer 31 at the base 17B of the second side 18B. On the other hand, the upper limit of the ratio of the thickness of the drug layer 31 at the base 17B of the first side 18A to the thickness of the drug layer 31 at the base 17B of the second side 18B is not particularly limited, and the drug layer 31 may not be present at the base 17B of the second side 18B, or may be present at a very thin thickness. For example, in one convex streak 17, the thickness of the drug layer 31 at the base 17B of the first side 18A may be 100 times or less, 50 times or less, 30 times or less, 20 times or less, or 10 times or less, of the thickness of the drug layer 31 at the base 17B of the second side 18B.
　バルーン１０は、直管部１３の長手方向の少なくとも一部において、凸条１７の第１側面１８Ａの基部１７Ｂにおける薬剤層３１の厚みが、第２側面１８Ｂの基部１７Ｂにおける薬剤層３１の厚みよりも厚く形成されていればよいが、好ましくは、直管部１３の長手方向の中央１／２の領域の半分以上において薬剤層３１がそのように形成されており、より好ましくは、直管部１３の長手方向の中央１／２の領域の２／３以上において薬剤層３１がそのように形成されており、さらに好ましくは、直管部１３の長手方向の中央１／２の領域の全体において薬剤層３１がそのように形成されている。例えば、直管部１３の長手方向の相対位置として直管部１３の近位端を０％とし遠位端を１００％としたときに、直管部１３の２５％～７５％の範囲を１０％刻みで６箇所で径方向に切断し、各切断断面の基部１７Ｂにおける薬剤層３１の厚みを計測して、３箇所以上においてそのように形成されていることが好ましい。これにより、直管部１３の長手方向の中央１／２の領域の半分以上において、凸条１７の第１側面１８Ａの基部１７Ｂにおける薬剤層３１の厚みが、第２側面１８Ｂの基部１７Ｂにおける薬剤層３１の厚みよりも厚く形成されていると判定することができる。薬剤層３１は、直管部１３の長手方向の全体において、凸条１７の第１側面１８Ａの基部１７Ｂにおける薬剤層３１の厚みが、第２側面１８Ｂの基部１７Ｂにおける薬剤層３１の厚みよりも厚く形成されていてもよい。 In the balloon 10, it is sufficient that the thickness of the drug layer 31 at the base 17B of the first side 18A of the convex rib 17 is thicker than the thickness of the drug layer 31 at the base 17B of the second side 18B in at least a portion of the longitudinal direction of the straight tube section 13; preferably, the drug layer 31 is so formed in more than half of the central 1/2 region in the longitudinal direction of the straight tube section 13; more preferably, the drug layer 31 is so formed in more than 2/3 of the central 1/2 region in the longitudinal direction of the straight tube section 13; and even more preferably, the drug layer 31 is so formed in the entire central 1/2 region in the longitudinal direction of the straight tube section 13. For example, when the relative position in the longitudinal direction of the straight tube section 13 is 0% at the proximal end of the straight tube section 13 and 100% at the distal end, the straight tube section 13 is cut radially at 6 locations at 10% intervals over a range of 25% to 75% and the thickness of the drug layer 31 at the base 17B of each cut cross section is measured, and it is preferable that the drug layer 31 is formed in this manner at three or more locations. This makes it possible to determine that the drug layer 31 at the base 17B of the first side surface 18A of the convex rib 17 is formed thicker than the drug layer 31 at the base 17B of the second side surface 18B in more than half of the central 1/2 region in the longitudinal direction of the straight tube section 13. The drug layer 31 may be formed such that the drug layer 31 at the base 17B of the first side surface 18A of the convex rib 17 is thicker than the drug layer 31 at the base 17B of the second side surface 18B over the entire longitudinal direction of the straight tube section 13.
　直管部１３の長手方向の垂直断面において、薬剤層３１は、凸条１７の５０％の高さの地点１７Ｃにおいて、凸条１７の第１側面１８Ａに存在することが好ましい（図６を参照）。このように凸条１７に薬剤層３１が設けられていれば、血管壁内部のより奥まで薬剤を届けることができる。凸条１７の５０％の高さの地点１７Ｃは、側面１８において基部１７Ｂにおける径方向の位置を０％、頂部１７Ａにおける径方向の位置を１００％としたときの、凸条１７の径方向の相対的位置を百分率で表したものである。第１側面１８Ａにおいて、薬剤層３１は凸条１７の０％～５０％の高さの全体にわたって存在することがより好ましい。薬剤層３１は、凸条１７の７５％の高さの地点において、凸条１７の第１側面１８Ａに存在していてもよく、この場合、第１側面１８Ａにおいて、薬剤層３１は凸条１７の０％～７５％の高さの全体にわたって存在することが好ましい。 In a longitudinal vertical cross section of the straight tube section 13, it is preferable that the drug layer 31 is present on the first side surface 18A of the convex rib 17 at point 17C, which is 50% of the height of the convex rib 17 (see Figure 6). If the drug layer 31 is provided on the convex rib 17 in this manner, the drug can be delivered deeper inside the blood vessel wall. Point 17C, which is 50% of the height of the convex rib 17, represents the relative radial position of the convex rib 17 as a percentage, when the radial position at base 17B on side surface 18 is 0%, and the radial position at top 17A is 100%. It is more preferable that the drug layer 31 is present over the entire 0% to 50% height of the convex rib 17 on the first side surface 18A. The drug layer 31 may be present on the first side 18A of the ridge 17 at a point that is 75% of the height of the ridge 17, and in this case, it is preferable that the drug layer 31 is present over the entire first side 18A from 0% to 75% of the height of the ridge 17.
　直管部１３の外面には、凸条１７の側面１８とともに凸条非存在領域２２にも薬剤層３１が設けられることが好ましい。凸条非存在領域２２にも薬剤層３１が設けられていれば、狭窄部においてバルーン１０を拡張させた際に、狭窄部の血管内面の広い範囲に薬剤を届けることができる。 It is preferable that a drug layer 31 is provided on the outer surface of the straight tube section 13, not only on the side surface 18 of the ridges 17 but also in the non-ridge regions 22. If a drug layer 31 is provided in the non-ridge regions 22, when the balloon 10 is expanded at the stenosis, the drug can be delivered to a wide area of the inner surface of the blood vessel at the stenosis.
　一実施形態として、図６および図７に示すように、凸条１７は、頂部１７Ａに向かって幅が狭まる部分を有し、かつ頂部１７Ａに向かって幅が広がる部分を有しないように形成されてもよい。すなわち、凸条１７の側面１８は、凸条１７の頂部１７Ａを通り径方向に延びる仮想直線１７Ｌに対して、頂部１７Ａに向かって仮想直線１７Ｌに近付く部分を有し、頂部１７Ａに向かって仮想直線１７Ｌから遠ざかる部分を有しないように形成されてもよい。このように凸条１７が形成されていれば、狭窄部においてバルーン１０を拡張させた際、凸条１７が血管内面に強く押し当てられても、凸条１７が折れ曲がったりせずに、狭窄部に食い込みやすくなる。凸条１７は、基部１７Ｂから頂部１７Ａの全体にわたって、頂部１７Ａに向かって幅が狭まるように形成されてもよい。すなわち、凸条１７の側面１８は、凸条１７の基部１７Ｂから頂部１７Ａの全体にわたって、頂部１７Ａに向かって仮想直線１７Ｌに近付くように形成されてもよい。 6 and 7, the ridges 17 may be formed to have a portion that narrows toward the apex 17A and not have a portion that widens toward the apex 17A. That is, the side surface 18 of the ridges 17 may be formed to have a portion that approaches the imaginary straight line 17L toward the apex 17A with respect to the imaginary straight line 17L that passes through the apex 17A of the ridges 17 and extends radially, and not have a portion that moves away from the imaginary straight line 17L toward the apex 17A. If the ridges 17 are formed in this manner, even if the ridges 17 are pressed strongly against the inner surface of the blood vessel when the balloon 10 is expanded at the stenosis, the ridges 17 do not bend and are easily embedded in the stenosis. The ridges 17 may be formed to narrow toward the apex 17A from the base 17B to the entire apex 17A. That is, the side surface 18 of the ridge 17 may be formed so as to approach the imaginary straight line 17L from the base 17B of the ridge 17 to the entire top 17A toward the top 17A.
　凸条１７は、図６に示すように、頂部１７Ａに向かって無段状に幅が狭まるように形成されていてもよく、図７に示すように、頂部１７Ａに向かって段状に幅が狭まるように形成されていてもよい。前者の場合、凸条１７の側面１８は、直管部１３の長手方向の垂直断面において、仮想直線１７Ｌに対して斜めに延びる直線状に形成されたり、径方向の外方に膨らんだ曲線状（一部に直線状の部分が含まれていてもよい）に形成されたり、径方向の内方に膨らんだ曲線状（一部に直線状の部分が含まれていてもよい）に形成されればよい。後者の場合、凸条１７は、基部１７Ｂから頂部１７Ａに至る少なくとも一部に、頂部１７Ａに向かって段状に幅が狭まる部分を有していればよい。 The ridges 17 may be formed so that their width narrows steplessly toward the apex 17A as shown in FIG. 6, or may be formed so that their width narrows stepwise toward the apex 17A as shown in FIG. 7. In the former case, the side surfaces 18 of the ridges 17 may be formed in a vertical cross section in the longitudinal direction of the straight pipe section 13 in a straight line extending obliquely with respect to the imaginary straight line 17L, in a curved line bulging radially outward (which may include a straight line portion), or in a curved line bulging radially inward (which may include a straight line portion). In the latter case, the ridges 17 may have at least a portion from the base 17B to the apex 17A where their width narrows stepwise toward the apex 17A.
　凸条１７が頂部１７Ａに向かって段状に幅が狭まる部分を有するように形成される場合、凸条１７は次のように薬剤層３１が形成されることが好ましい。すなわち、凸条１７は、頂部１７Ａに向かって段状に幅が狭まる部分として、バルーン本体部１６の外面に隣接した第１段部分１９と、それよりも頂部１７Ａ側の第２段部分２０を有し、第１段部分１９の第１側面１８Ａの基部１９Ｂにおける薬剤層３１の厚みが、第２段部分２０の第１側面１８Ａの基部２０Ｂにおける薬剤層３１の厚みよりも厚く形成されることが好ましい。このように薬剤層３１が形成されることにより、凸条１７の第２段部分２０が狭窄部に食い込みやすくなり、バルーン１０によって狭窄部を効果的に拡張させることができる。また、凸条１７の第１段部分１９の第１側面１８Ａの基部１９Ｂに薬剤層３１がより厚く存在することにより、血管壁の中膜に存在する平滑筋細胞の血管内面への遊走を抑止することができる。第２段部分２０の第１側面１８Ａの基部２０Ｂには薬剤層３１が存在しなくてもよく、また、第２段部分２０の側面１８に薬剤層３１が全く存在しなくてもよい。なお、第２段部分２０の基部２０Ｂに薬剤層３１が存在する場合の第２段部分２０の基部２０Ｂにおける薬剤層３１の厚みは、直管部１３の長手方向の垂直断面において、凸条１７の第２段部分２０の基部２０Ｂから薬剤層３１の表面までの最短長さを意味する。また、凸条１７の第１段部分１９の基部１９Ｂは凸条１７の基部１７Ｂと一致し、凸条１７の第１段部分１９の基部１９Ｂにおける薬剤層３１の厚みは、凸条１７の基部１７Ｂにおける薬剤層３１の厚みに相当する。 When the ridge 17 is formed to have a portion in which the width narrows stepwise toward the apex 17A, the ridge 17 is preferably formed with the drug layer 31 as follows. That is, the ridge 17 has a first step portion 19 adjacent to the outer surface of the balloon body 16 and a second step portion 20 on the apex 17A side of the first step portion 19, as a portion in which the width narrows stepwise toward the apex 17A, and it is preferable that the thickness of the drug layer 31 at the base 19B of the first side 18A of the first step portion 19 is formed thicker than the thickness of the drug layer 31 at the base 20B of the first side 18A of the second step portion 20. By forming the drug layer 31 in this manner, the second step portion 20 of the ridge 17 is more likely to bite into the narrowed portion, and the narrowed portion can be effectively expanded by the balloon 10. In addition, the drug layer 31 is thicker at the base 19B of the first side 18A of the first step portion 19 of the ridge 17, and migration of smooth muscle cells present in the tunica media of the vascular wall to the inner surface of the blood vessel can be suppressed. The drug layer 31 may not be present at the base 20B of the first side surface 18A of the second step portion 20, and the drug layer 31 may not be present at all on the side surface 18 of the second step portion 20. When the drug layer 31 is present at the base 20B of the second step portion 20, the thickness of the drug layer 31 at the base 20B of the second step portion 20 means the shortest length from the base 20B of the second step portion 20 of the ridge 17 to the surface of the drug layer 31 in a vertical cross section in the longitudinal direction of the straight tube portion 13. In addition, the base 19B of the first step portion 19 of the ridge 17 coincides with the base 17B of the ridge 17, and the thickness of the drug layer 31 at the base 19B of the first step portion 19 of the ridge 17 corresponds to the thickness of the drug layer 31 at the base 17B of the ridge 17.
　他の実施形態として、凸条１７は、頂部１７Ａに向かって幅が広がる部分を有し、当該部分よりも頂部１７Ａ側に、頂部１７Ａに向かって幅が狭まる部分を有するように形成されてもよい。図８に示すように、直管部１３の長手方向の垂直断面において、凸条１７の第１側面１８Ａは、凸条１７の頂部１７Ａを通り径方向に延びる仮想直線１７Ｌに対して、頂部１７Ａに向かって仮想直線１７Ｌから遠ざかる部分１８Ｒと、当該部分よりも頂部１７Ａ側に、頂部１７Ａに向かって仮想直線１７Ｌに近付く部分１８Ｓを有するように形成されていてもよい。この場合、凸条１７の第１側面１８Ａの一部が窪んで形成される。そのため、凸条１７の第１側面１８Ａの窪んだ部分により多くの薬剤を保持させることが可能となる。凸条１７において、第１側面１８Ａが頂部１７Ａに向かって仮想直線１７Ｌから遠ざかる部分１８Ｒは、凸条１７の少なくとも０％～３０％の高さの範囲の少なくとも一部に形成されることが好ましく、凸条１７の５０％～１００％の高さには形成されないことが好ましい。これにより、凸条１７の第１側面１８Ａの基部１７Ｂにより多くの薬剤を保持させることができる。 In another embodiment, the ridge 17 may be formed to have a portion that widens toward the apex 17A, and a portion that narrows toward the apex 17A from the portion. As shown in FIG. 8, in a vertical cross section of the straight tube section 13 in the longitudinal direction, the first side 18A of the ridge 17 may be formed to have a portion 18R that moves away from the imaginary straight line 17L toward the apex 17A with respect to the imaginary straight line 17L that passes through the apex 17A of the ridge 17 and extends in the radial direction, and a portion 18S that moves closer to the imaginary straight line 17L toward the apex 17A from the portion. In this case, a portion of the first side 18A of the ridge 17 is formed to be recessed. Therefore, it is possible to hold more medicine in the recessed portion of the first side 18A of the ridge 17. In the convex streak 17, the portion 18R where the first side surface 18A moves away from the imaginary straight line 17L toward the top 17A is preferably formed in at least a part of the range of at least 0% to 30% of the height of the convex streak 17, and is preferably not formed in the range of 50% to 100% of the height of the convex streak 17. This allows more medicine to be held by the base 17B of the first side surface 18A of the convex streak 17.
　薬剤層３１は、直管部１３の外面に加えて、近位側テーパー部１２の外面および／または遠位側テーパー部１４の外面にも設けられていてもよい。これにより、狭窄部の広い範囲に薬剤を届けることができる。 The drug layer 31 may be provided on the outer surface of the proximal tapered section 12 and/or the outer surface of the distal tapered section 14 in addition to the outer surface of the straight tube section 13. This allows the drug to be delivered to a wide area of the stenosis.
　バルーン１０は、上記のように直管部１３の外面に薬剤層３１が設けられた上で、バルーン１０が収縮されて折り畳まれている。バルーン１０は、収縮されて折り畳まれることにより、径方向の大きさが小さく形成され、ガイディングカテーテルやシース内などに挿通して血管の狭窄部などの処置対象部に送達することが容易になる。 As described above, the balloon 10 is contracted and folded after the drug layer 31 is provided on the outer surface of the straight tube portion 13. By contracting and folding the balloon 10, the radial size is reduced, making it easier to insert the balloon 10 into a guiding catheter or sheath and deliver it to the treatment target area, such as a narrowed part of a blood vessel.
　図９および図１０には、図５に示したバルーン１０を収縮させて折り畳んだ例を示した。図９および図１０に示すように、バルーン１０の収縮状態で、直管部１３は、バルーン本体部１６の内面を内側にして凸条非存在領域２２に形成された折り曲げ線２４で折り返されて、凸条非存在領域２２が重ね合わされた折り畳み羽根部２３が形成され、折り畳み羽根部２３が凸条１７の少なくとも一部を覆うように直管部１３の外面に重ねられている。詳細には、折り畳み羽根部２３は折り曲げ線２４を挟んだ一方側の第１部分２３Ａと他方側の第２部分２３Ｂを有し、凸条非存在領域２２が折り曲げ線２４で折り返されることにより、折り畳み羽根部２３の第１部分２３Ａと第２部分２３Ｂとが重ね合わされ、重ね合わされた折り畳み羽根部２３の第１部分２３Ａと第２部分２３Ｂが、凸条１７の少なくとも一部を覆うように直管部１３の外面に重ねられている。このように凸条非存在領域２２どうしが重ね合わされた折り畳み羽根部２３が直管部１３の外面に重ねられることにより、バルーン１０が折り畳まれている。 9 and 10 show an example in which the balloon 10 shown in Fig. 5 is deflated and folded. As shown in Fig. 9 and 10, when the balloon 10 is in a deflated state, the straight tube section 13 is folded back at the fold line 24 formed in the non-convex streak region 22 with the inner surface of the balloon body 16 facing inward, forming a folded wing section 23 in which the non-convex streak region 22 is overlapped, and the folded wing section 23 is overlapped on the outer surface of the straight tube section 13 so as to cover at least a portion of the convex streak 17. In detail, the folding wing portion 23 has a first portion 23A on one side of the folding line 24 and a second portion 23B on the other side, and the ridge-free region 22 is folded back at the folding line 24, so that the first portion 23A and the second portion 23B of the folding wing portion 23 are overlapped, and the overlapped first portion 23A and the second portion 23B of the folding wing portion 23 are overlapped on the outer surface of the straight pipe portion 13 so as to cover at least a part of the ridge 17. The balloon 10 is folded by overlapping the folding wing portion 23 with the ridge-free region 22 overlapping each other on the outer surface of the straight pipe portion 13 in this way.
　折り曲げ線２４は、凸条１７の延在方向に対して略平行に延びるように形成されることが好ましい。凸条非存在領域２２は、折り曲げ線２４において明確な折り目が形成されるように折り返されてもよく、先端が丸まって折り返されていてもよい。なお、バルーン本体部１６の凸条非存在領域２２は通常ある程度の厚みと弾性を有するため、凸条非存在領域２２は折り曲げ線２４において先端が丸まって折り返される。この場合、直管部１３の長手方向の垂直断面で見て、凸条非存在領域２２が折り返された先端部が折り曲げ線２４となる。 The fold lines 24 are preferably formed so as to extend approximately parallel to the extension direction of the ridges 17. The non-ridge region 22 may be folded back so as to form a clear crease at the fold line 24, or may be folded back with a rounded tip. Note that since the non-ridge region 22 of the balloon body 16 usually has a certain degree of thickness and elasticity, the non-ridge region 22 is folded back with a rounded tip at the fold line 24. In this case, when viewed in a vertical cross section in the longitudinal direction of the straight tube section 13, the tip where the non-ridge region 22 is folded back becomes the fold line 24.
　折り曲げ線２４は、バルーン１０の外側から見て、山折りとして形成される。折り畳み羽根部２３は、バルーン本体部１６の凸条非存在領域２２のみから形成され、凸条存在領域２１を含んで形成されないことが好ましい。直管部１３には、折り曲げ線２４に対して周方向の一方側および／または他方側に、バルーン本体部１６の外面を内側にして折り返された折り曲げ線（バルーン１０の外側から見て谷折り線）が形成されていてもよい。この場合、谷折り線となる折り曲げ線は、折り畳み羽根部２３の基部を形成することが好ましい。折り曲げ線２４（すなわちバルーン１０の外側から見て山折りとなる折り曲げ線）は、１つの凸条非存在領域２２に１つのみ形成されることが好ましく、折り畳み羽根部２３は周方向の一方側に傾倒していることが好ましい。 The fold line 24 is formed as a mountain fold when viewed from the outside of the balloon 10. It is preferable that the folding wing portion 23 is formed only from the non-ridge region 22 of the balloon body portion 16, and is not formed including the ridge region 21. The straight tube portion 13 may have a fold line (a valley fold line when viewed from the outside of the balloon 10) that is folded back with the outer surface of the balloon body portion 16 facing inward on one side and/or the other side of the fold line 24 in the circumferential direction. In this case, the fold line that becomes the valley fold line preferably forms the base of the folding wing portion 23. It is preferable that only one fold line 24 (i.e., a fold line that becomes a mountain fold when viewed from the outside of the balloon 10) is formed in one non-ridge region 22, and it is preferable that the folding wing portion 23 is inclined to one side in the circumferential direction.
　折り畳み羽根部２３は、第１側面１８Ａ側から凸条１７の少なくとも一部を覆うように直管部１３の外面に重ねられている。このようにバルーン１０が折り畳まれることにより、バルーン１０が処置対象部に送達されるまでに薬剤層３１が脱落しにくくなるとともに、バルーン１０の折り畳み状態が安定して保持されやすくなる。すなわち、凸条１７の第１側面１８Ａの基部１７Ｂには薬剤層３１が比較的厚く設けられているが、このように薬剤層３１が設けられた凸条１７に対して折り畳み羽根部２３が第１側面１８Ａ側から重ねられることにより、薬剤層３１が折り畳み羽根部２３によって保護され、バルーン１０を処置対象部に送達されるまでに薬剤層３１が脱落しにくくなる。また、折り畳み羽根部２３が、薬剤層３１が比較的厚く設けられた第１側面１８Ａ側から凸条１７を覆うことにより、薬剤層３１が接着剤として機能し、折り畳み羽根部２３と凸条１７の第１側面１８Ａとの密着性を高めることができる。その結果、バルーン１０の折り畳み状態が安定化され、薬剤を安定して処置対象部まで送達することができる。 The folding wing portion 23 is overlapped on the outer surface of the straight tube portion 13 so as to cover at least a portion of the convex rib 17 from the first side surface 18A side. By folding the balloon 10 in this manner, the drug layer 31 is less likely to fall off before the balloon 10 is delivered to the treatment target area, and the folded state of the balloon 10 is more likely to be stably maintained. That is, the drug layer 31 is provided relatively thickly on the base 17B of the first side surface 18A of the convex rib 17, but by overlapping the folding wing portion 23 from the first side surface 18A side with the convex rib 17 on which the drug layer 31 is provided, the drug layer 31 is protected by the folding wing portion 23, and the drug layer 31 is less likely to fall off before the balloon 10 is delivered to the treatment target area. In addition, by having the folding wing portion 23 cover the ridge 17 from the first side 18A side where the drug layer 31 is relatively thick, the drug layer 31 functions as an adhesive, improving the adhesion between the folding wing portion 23 and the first side 18A of the ridge 17. As a result, the folded state of the balloon 10 is stabilized, and the drug can be stably delivered to the treatment target area.
　図９および図１０に示すように、折り畳み羽根部２３は凸条１７の頂部１７Ａを覆っていることが好ましい。このようにバルーン１０が折り畳まれていれば、凸条１７の第１側面１８Ａに設けられた薬剤層３１が折り畳み羽根部２３によって保護され、バルーン１０が処置対象部に送達されるまでに薬剤層３１がバルーン１０から脱落しにくくなる。また、バルーン１０が処置対象部に送達される際に凸条１７の頂部１７Ａが露出せず、折り畳まれたバルーン１０をガイディングカテーテルやシース内にスムーズに挿通させることができる。 As shown in Figures 9 and 10, it is preferable that the folding wing portion 23 covers the top 17A of the ridge 17. If the balloon 10 is folded in this manner, the drug layer 31 provided on the first side surface 18A of the ridge 17 is protected by the folding wing portion 23, making it difficult for the drug layer 31 to fall off the balloon 10 before the balloon 10 is delivered to the treatment target area. In addition, the top 17A of the ridge 17 is not exposed when the balloon 10 is delivered to the treatment target area, and the folded balloon 10 can be smoothly inserted into a guiding catheter or sheath.
　図１０に示すように、折り畳み羽根部２３は凸条１７の第２側面１８Ｂを覆い、折り畳み羽根部２３の折り曲げ線２４が凸条非存在領域２２と重なる位置にあってもよい。これにより、バルーン１０をよりタイトに折り畳むことができる。図面には示されていないが、折り畳み羽根部２３の折り曲げ線２４は、周方向に隣接する折り畳み羽根部２３と重なる位置にあってもよい。 As shown in FIG. 10, the folding wing portion 23 may cover the second side surface 18B of the ridge 17, and the fold line 24 of the folding wing portion 23 may be positioned so as to overlap the ridge-free region 22. This allows the balloon 10 to be folded more tightly. Although not shown in the drawing, the fold line 24 of the folding wing portion 23 may be positioned so as to overlap an adjacent folding wing portion 23 in the circumferential direction.
　次に、本発明のバルーンカテーテルの製造方法について説明する。本発明の実施の形態に係るバルーンカテーテルの製造方法は、外面に凸条を有するバルーンを準備する工程（以下、「バルーン準備工程」と称する）と、バルーンを拡張させた状態で、バルーンの直管部の外面に薬液を塗布し、凸条の一方側の第１側面の基部に他方側の第２側面の基部よりも厚く薬剤層を形成する工程（以下、「薬剤層形成工程」と称する）と、バルーンを収縮させ、直管部を凸条非存在領域で折り返して折り畳み羽根部を形成し、折り畳み羽根部を第１側面側から凸条の少なくとも一部を覆うように直管部の外面に重ねることにより、バルーンを折り畳む工程（以下、「バルーン折り畳み工程」と称する）を有する。 Next, a method for manufacturing a balloon catheter of the present invention will be described. The method for manufacturing a balloon catheter according to an embodiment of the present invention includes a step of preparing a balloon having a ridge on its outer surface (hereinafter referred to as the "balloon preparation step"); a step of applying a drug solution to the outer surface of the straight tube section of the balloon while the balloon is inflated, and forming a drug layer at the base of a first side surface on one side of the ridge that is thicker than the base of a second side surface on the other side (hereinafter referred to as the "drug layer formation step"); and a step of deflating the balloon, folding back the straight tube section in the non-ridge area to form a folding wing section, and folding the balloon by overlapping the folding wing section on the outer surface of the straight tube section so as to cover at least a portion of the ridge from the first side surface side (hereinafter referred to as the "balloon folding step").
　バルーン準備工程では、上記に説明したバルーン１０を準備する。すなわち、近位側から遠位側に延びる長手方向と長手方向に垂直な径方向とを有するバルーン１０であって、直管部１３と、直管部１３よりも近位側に位置する近位側テーパー部１２と、直管部１３よりも遠位側に位置する遠位側テーパー部１４とを有し、直管部１３が、筒形状のバルーン本体部１６と、バルーン本体部１６の外面に径方向の外方に突出し長手方向に延在している凸条１７とを有するバルーン１０を準備する。バルーン１０の構成や好適態様の詳細は上記の説明が参照される。 In the balloon preparation process, the balloon 10 described above is prepared. That is, the balloon 10 has a longitudinal direction extending from the proximal side to the distal side and a radial direction perpendicular to the longitudinal direction, and has a straight tube section 13, a proximal tapered section 12 located proximal to the straight tube section 13, and a distal tapered section 14 located distal to the straight tube section 13, and the straight tube section 13 has a cylindrical balloon main body section 16 and a convex rib 17 that protrudes radially outward from the outer surface of the balloon main body section 16 and extends in the longitudinal direction. The above explanation is referred to for details of the configuration and preferred embodiments of the balloon 10.
　薬剤層形成工程では、バルーン１０を拡張させた状態で、直管部１３の外面に薬液を塗布し、凸条１７の一方側の第１側面１８Ａの基部１７Ｂに他方側の第２側面１８Ｂの基部１７Ｂよりも厚く薬剤層３１を形成する。薬液の塗布方法は特に限定されず、例えば、刷毛、スプレー、コーター等により直管部１３の外面に薬液を塗布してもよく、バルーン１０を薬液に浸漬することにより直管部１３の外面に薬液を塗布してもよい。必要に応じて、薬剤層３１を形成しない部分にマスキングを施した上で、直管部１３の外面に薬液を塗布してもよい。 In the drug layer forming process, while the balloon 10 is in an expanded state, a drug solution is applied to the outer surface of the straight pipe section 13, and a drug layer 31 is formed at the base 17B of the first side surface 18A on one side of the convex rib 17, which is thicker than the base 17B of the second side surface 18B on the other side. The method of applying the drug solution is not particularly limited, and for example, the drug solution may be applied to the outer surface of the straight pipe section 13 with a brush, spray, coater, etc., or the drug solution may be applied to the outer surface of the straight pipe section 13 by immersing the balloon 10 in the drug solution. If necessary, the drug solution may be applied to the outer surface of the straight pipe section 13 after masking the parts where the drug layer 31 is not to be formed.
　凸条１７の第１側面１８Ａの基部１７Ｂに、凸条１７の第２側面１８Ｂの基部１７Ｂよりも薬剤層３１を厚く形成することが容易な点から、図１１に示すように、薬剤層形成工程では、バルーン１０の直管部１３の外面に薬液３３を塗布し、バルーン１０を長手方向に延びる中心軸を中心に回転させることが好ましい。図１１には、図２に示したバルーン１０の長手方向の垂直断面図が示されており、バルーン１０の直管部１３の外面に薬液３３を塗布している状態が示されている。直管部１３の外面に薬液３３を塗布し、バルーン１０を長手方向に延びる中心軸を中心に回転させることにより、直管部１３の外面、特に凸条非存在領域２２に塗布された薬液３３が直管部１３の表面を周方向に移動して凸条１７の側面１８に溜まり、凸条１７の側面１８や基部１７Ｂにより厚く薬剤層３１を形成することができる。この際、バルーン１０を、長手方向に延びる中心軸を中心に一方向に優先して回転させることにより、凸条１７の第１側面１８Ａにより厚く薬剤層３１を形成することができる。バルーン１０を長手方向に延びる中心軸を中心に一方向に優先して回転させる態様には、バルーン１０を長手方向に延びる中心軸を中心に一方向のみに回転させる態様、バルーン１０を長手方向に延びる中心軸を中心に一方向に他方向よりも回転数が多くなるように回転させる態様、バルーン１０を長手方向に延びる中心軸を中心に一方向に他方向よりも速い回転速度で回転させる態様が含まれる。 Since it is easier to form a thicker drug layer 31 at the base 17B of the first side 18A of the convex rib 17 than at the base 17B of the second side 18B of the convex rib 17, it is preferable to apply drug solution 33 to the outer surface of the straight tube section 13 of the balloon 10 and rotate the balloon 10 around the central axis extending in the longitudinal direction in the drug layer formation process, as shown in Figure 11. Figure 11 shows a vertical cross-sectional view of the longitudinal direction of the balloon 10 shown in Figure 2, showing the state in which drug solution 33 is applied to the outer surface of the straight tube section 13 of the balloon 10. By applying drug solution 33 to the outer surface of the straight tube section 13 and rotating the balloon 10 around the central axis extending in the longitudinal direction, the drug solution 33 applied to the outer surface of the straight tube section 13, particularly the convex rib non-existent region 22, moves circumferentially around the surface of the straight tube section 13 and accumulates on the side 18 of the convex rib 17, and a thicker drug layer 31 can be formed on the side 18 of the convex rib 17 and the base 17B. In this case, by preferentially rotating the balloon 10 in one direction around the central axis extending in the longitudinal direction, a thicker drug layer 31 can be formed on the first side surface 18A of the protrusion 17. Modes in which the balloon 10 is preferentially rotated in one direction around the central axis extending in the longitudinal direction include a mode in which the balloon 10 is rotated in only one direction around the central axis extending in the longitudinal direction, a mode in which the balloon 10 is rotated around the central axis extending in the longitudinal direction so that the number of rotations in one direction is greater than in the other directions, and a mode in which the balloon 10 is rotated around the central axis extending in the longitudinal direction at a faster rotation speed in one direction than in the other directions.
　薬液３３に含まれる薬剤は、上記の説明が参照される。薬液３３は、薬剤を溶解または分散する溶媒が含まれることが好ましい。薬液３３の薬剤濃度は特に限定されず、直管部１３の外面に塗布可能であり、直管部１３の表面で流動性が確保されるように、適宜濃度を調整すればよい。 For the chemical contained in the chemical solution 33, see the above description. The chemical solution 33 preferably contains a solvent that dissolves or disperses the chemical. There are no particular limitations on the concentration of the chemical in the chemical solution 33, and the concentration can be adjusted appropriately so that the chemical can be applied to the outer surface of the straight pipe section 13 and fluidity is ensured on the surface of the straight pipe section 13.
　薬液３３の塗布方法は特に限定されないが、図１１に示すようにスプレーにより直管部１３の外面に薬液３３を塗布することが好ましく、これにより直管部１３の外面に任意の量の薬液３３を広く塗布することが容易になる。また、直管部１３の外面に薬剤層３１を形成することが容易になる。 The method of applying the drug solution 33 is not particularly limited, but it is preferable to apply the drug solution 33 to the outer surface of the straight pipe section 13 by spraying as shown in FIG. 11, which makes it easy to widely apply any amount of drug solution 33 to the outer surface of the straight pipe section 13. It also makes it easy to form a drug layer 31 on the outer surface of the straight pipe section 13.
　薬剤層形成工程では、バルーン１０を長手方向に延びる中心軸を中心に回転させながら、直管部１３の外面に薬液３３を塗布してもよく、直管部１３の外面に薬液３３を塗布した後、バルーン１０を長手方向に延びる中心軸を中心に回転させてもよい。いずれの場合も、直管部１３の外面に塗布された薬液３３が、直管部１３の表面を周方向に移動して凸条１７の基部１７Ｂに溜まるようにすることができる。 In the drug layer formation process, the drug solution 33 may be applied to the outer surface of the straight tube section 13 while the balloon 10 is rotated around a central axis extending in the longitudinal direction, or after the drug solution 33 is applied to the outer surface of the straight tube section 13, the balloon 10 may be rotated around a central axis extending in the longitudinal direction. In either case, the drug solution 33 applied to the outer surface of the straight tube section 13 can move circumferentially around the surface of the straight tube section 13 and accumulate at the base 17B of the ridge 17.
　薬剤層形成工程では、バルーン１０は、長手方向に延びる中心軸を中心に一方向のみに回転させてもよく、一方向とその反対方向の両方向に順番に回転させてもよい。バルーン１０の回転方向を適宜設定することにより、凸条１７の第１側面１８Ａの基部１７Ｂと第２側面１８Ｂの基部１７Ｂに形成する薬剤層３１の厚みを任意に調整することができる。 In the drug layer formation process, the balloon 10 may be rotated in only one direction around a central axis extending in the longitudinal direction, or may be rotated in both one direction and the opposite direction in turn. By appropriately setting the rotation direction of the balloon 10, the thickness of the drug layer 31 formed on the base 17B of the first side 18A and the base 17B of the second side 18B of the ridge 17 can be adjusted as desired.
　薬剤層形成工程では、バルーン１０を回転させながら、薬液３３に含まれる溶媒の少なくとも一部を蒸発させることが好ましい。これにより、直管部１３の外面に薬剤層３１を形成することが容易になる。溶媒の蒸発は、薬液３３を塗布したバルーン１０を加熱することにより行ってもよく、薬液３３を塗布したバルーン１０を減圧状態に置くことにより行ってもよく、薬液３３を塗布したバルーン１０に風を当てることにより行ってもよい。また、溶媒として適度な蒸気圧を有する溶媒を選択することにより、バルーン１０を回転させながら溶媒が自然に蒸発するようにしてもよい。 In the drug layer formation process, it is preferable to evaporate at least a portion of the solvent contained in the drug solution 33 while rotating the balloon 10. This makes it easier to form the drug layer 31 on the outer surface of the straight tube section 13. The solvent may be evaporated by heating the balloon 10 to which the drug solution 33 has been applied, by placing the balloon 10 to which the drug solution 33 has been applied in a reduced pressure state, or by blowing air on the balloon 10 to which the drug solution 33 has been applied. In addition, by selecting a solvent with an appropriate vapor pressure as the solvent, the solvent may be allowed to evaporate naturally while rotating the balloon 10.
　バルーン折り畳み工程では、薬剤層３１を形成したバルーン１０を収縮させ、直管部１３を凸条非存在領域２２においてバルーン本体部１６の内面を内側にして折り返して、凸条非存在領域２２が重ね合わされた折り畳み羽根部２３を形成する。直管部１３は、折り曲げ線２４においてバルーン本体部１６の内面を内側にして折り返し、これにより凸条非存在領域２２どうしが重ね合わされた折り畳み羽根部２３を形成することができる。折り畳み羽根部２３を形成する際、折り畳み羽根部２３の基部となる箇所で、直管部１３を、バルーン本体部１６の外面を内側にして折り返すことが好ましく、これにより折り畳み羽根部２３を形成することが容易になる。その後、折り畳み羽根部２３を、第１側面１８Ａ側から凸条１７の少なくとも一部を覆うように直管部１３の外面に重ねることにより、バルーン１０を折り畳むことができる。折り畳み羽根部２３は、凸条１７の頂部１７Ａを覆うように直管部１３の外面に重ねられることが好ましく、さらに凸条１７の第２側面１８Ｂを覆い、折り畳み羽根部２３の先端すなわち折り曲げ線２４が凸条非存在領域２２と重なるように直管部１３の外面に重ねられてもよい。 In the balloon folding process, the balloon 10 on which the drug layer 31 is formed is deflated, and the straight tube section 13 is folded back at the non-convex streak region 22 with the inner surface of the balloon body 16 facing inward to form the folded wing section 23 in which the non-convex streak region 22 is overlapped. The straight tube section 13 is folded back at the folding line 24 with the inner surface of the balloon body 16 facing inward, thereby forming the folded wing section 23 in which the non-convex streak region 22 is overlapped. When forming the folded wing section 23, it is preferable to fold back the straight tube section 13 at the base of the folded wing section 23 with the outer surface of the balloon body 16 facing inward, which makes it easier to form the folded wing section 23. The folded wing section 23 is then folded over on the outer surface of the straight tube section 13 so as to cover at least a portion of the convex streak 17 from the first side surface 18A side, thereby folding the balloon 10. The folded wing portion 23 is preferably overlapped on the outer surface of the straight pipe portion 13 so as to cover the top 17A of the ridge 17, and may also be overlapped on the outer surface of the straight pipe portion 13 so as to cover the second side surface 18B of the ridge 17 and so that the tip of the folded wing portion 23, i.e., the fold line 24, overlaps with the ridge-free region 22.
　本願は、２０２２年１１月１６日に出願された日本国特許出願第２０２２－１８３６９４号に基づく優先権の利益を主張するものである。２０２２年１１月１６日に出願された日本国特許出願第２０２２－１８３６９４号の明細書の全内容が、本願に参考のため援用される。 This application claims the benefit of priority based on Japanese Patent Application No. 2022-183694, filed on November 16, 2022. The entire contents of the specification of Japanese Patent Application No. 2022-183694, filed on November 16, 2022, are incorporated by reference into this application.
　１：バルーンカテーテル
　２：シャフト
　５：ハブ
　１０：バルーン
　１１：近位側スリーブ部
　１２：近位側テーパー部
　１３：直管部
　１４：遠位側テーパー部
　１５：遠位側スリーブ部
　１６：バルーン本体部
　１７：凸条、１７Ａ：頂部、１７Ｂ：基部
　１８：側面、１８Ａ：第１側面、１８Ｂ：第２側面
　１９：第１段部分
　２０：第２段部分
　２１：凸条存在領域
　２２：凸条非存在領域
　２３：折り畳み羽根部
　２４：折り曲げ線
　３１：薬剤層
　３２：凸条の基部における薬剤層の厚み
　３３：薬液 LIST OF SYMBOLS 1: Balloon catheter 2: Shaft 5: Hub 10: Balloon 11: Proximal sleeve section 12: Proximal tapered section 13: Straight tube section 14: Distal tapered section 15: Distal sleeve section 16: Balloon body section 17: Ridge, 17A: Top, 17B: Base 18: Side, 18A: First side, 18B: Second side 19: First stage section 20: Second stage section 21: Ridge-present region 22: Ridge-free region 23: Folding wing section 24: Folding line 31: Drug layer 32: Thickness of drug layer at base of rib 33: Drug solution

Claims (12)

  1. 　近位側から遠位側に延びる長手方向と前記長手方向に垂直な径方向とを有するバルーンカテーテル用バルーンであって、
    　前記バルーンは、直管部と、前記直管部よりも近位側に位置する近位側テーパー部と、前記直管部よりも遠位側に位置する遠位側テーパー部とを有し、
    　前記直管部は、バルーン本体部と、前記バルーン本体部の外面に径方向の外方に突出した凸条とを有し、前記直管部の外面に凸条存在領域と凸条非存在領域が形成されており、
    　前記直管部の長手方向の垂直断面において、前記凸条は、前記凸条の頂部を通り径方向に延びる仮想直線に対して一方側にある第１側面と他方側にある第２側面を有し、
    　前記凸条の前記第１側面を含む前記直管部の外面に薬剤層が設けられており、
    　前記凸条の前記第１側面の基部における前記薬剤層の厚みは、前記凸条の前記第２側面の基部における前記薬剤層の厚みよりも厚く、
    　前記バルーンの収縮状態で、前記直管部は、前記バルーン本体部の内面を内側にして前記凸条非存在領域に形成された折り曲げ線で折り返されて、前記凸条非存在領域が重ね合わされた折り畳み羽根部が形成され、
    　前記折り畳み羽根部が、前記第１側面側から前記凸条の少なくとも一部を覆うように前記直管部の外面に重ねられることにより、前記バルーンが折り畳まれているバルーンカテーテル用バルーン。     A balloon for a balloon catheter having a longitudinal direction extending from a proximal side to a distal side and a radial direction perpendicular to the longitudinal direction,
    The balloon has a straight tube portion, a proximal tapered portion located proximally of the straight tube portion, and a distal tapered portion located distally of the straight tube portion,
    The straight pipe portion has a balloon main body and a protrusion protruding radially outward on an outer surface of the balloon main body, and a protrusion-existing region and a protrusion-free region are formed on the outer surface of the straight pipe portion,
    In a vertical cross section in a longitudinal direction of the straight pipe portion, the protrusion has a first side surface on one side and a second side surface on the other side with respect to an imaginary line passing through a top of the protrusion and extending in a radial direction,
    A drug layer is provided on an outer surface of the straight tube portion including the first side surface of the convex strip;
    a thickness of the drug layer at a base of the first side surface of the ridge is greater than a thickness of the drug layer at a base of the second side surface of the ridge;
    When the balloon is in a deflated state, the straight tube portion is folded back along the folding line formed in the non-ridge region with the inner surface of the balloon body portion facing inward, and a folded wing portion is formed in which the non-ridge regions are overlapped,
    A balloon for a balloon catheter, wherein the folding wing portion is overlapped on the outer surface of the straight tube portion so as to cover at least a portion of the convex strip from the first side surface side, thereby folding the balloon.
  2. 　前記折り畳み羽根部は前記凸条の頂部を覆っている請求項１に記載のバルーン。 The balloon of claim 1, wherein the folded wing portion covers the top of the ridge.
  3. 　前記折り畳み羽根部は前記凸条の前記第２側面を覆い、前記折り畳み羽根部の前記折り曲げ線が前記凸条非存在領域と重なる位置にある請求項１に記載のバルーン。 The balloon of claim 1, wherein the folded wing covers the second side of the ridge, and the fold line of the folded wing overlaps the non-ridge area.
  4. 　前記直管部の長手方向の垂直断面において、前記凸条の前記第１側面は、前記仮想直線に対して、前記凸条の頂部に向かって前記仮想直線から遠ざかる部分と、当該部分よりも頂部側に、前記凸条の頂部に向かって前記仮想直線に近付く部分を有する請求項１に記載のバルーン。 The balloon according to claim 1, wherein in a vertical cross section of the straight tube portion in the longitudinal direction, the first side of the ridge has a portion that moves away from the imaginary straight line toward the apex of the ridge, and a portion closer to the imaginary straight line toward the apex of the ridge than the portion toward the apex.
  5. 　前記直管部の長手方向の垂直断面において、前記凸条は、頂部に向かって段状に幅が狭まる部分を有する請求項１に記載のバルーン。 The balloon according to claim 1, wherein in a vertical cross section of the straight tube portion in the longitudinal direction, the ridge has a portion in which the width narrows in a stepped manner toward the apex.
  6. 　前記凸条は、前記頂部に向かって段状に幅が狭まる部分として、前記バルーン本体部の外面に隣接した第１段部分と、それよりも頂部側の第２段部分を有し、
    　前記第１段部分の前記第１側面の基部における前記薬剤層の厚みは、前記第２段部分の前記第１側面の基部における前記薬剤層の厚みよりも厚い請求項５に記載のバルーン。     The convex strip has a first step portion adjacent to the outer surface of the balloon body and a second step portion closer to the top, the first step portion being a portion whose width narrows in a step shape toward the top,
    6. The balloon of claim 5, wherein a thickness of the drug layer at a base of the first side of the first stage is greater than a thickness of the drug layer at a base of the first side of the second stage.
  7. 　前記凸条は、樹脂製、金属製、またはその組み合わせである請求項１に記載のバルーン。 The balloon according to claim 1, wherein the ridges are made of resin, metal, or a combination thereof.
  8. 　請求項１～７のいずれか一項に記載のバルーンを備えるバルーンカテーテル。 A balloon catheter comprising a balloon according to any one of claims 1 to 7.
  9. 　近位側から遠位側に延びる長手方向と前記長手方向に垂直な径方向とを有するバルーンであって、直管部と、前記直管部よりも近位側に位置する近位側テーパー部と、前記直管部よりも遠位側に位置する遠位側テーパー部とを有し、前記直管部が、バルーン本体部と、前記バルーン本体部の外面に径方向の外方に突出し長手方向に延在している凸条とを有とを有し、前記直管部の外面に凸条存在領域と凸条非存在領域が形成されたバルーンを準備する工程と、
    　前記バルーンを拡張させた状態で、前記直管部の外面に薬液を塗布し、前記凸条の一方側の第１側面の基部に他方側の第２側面の基部よりも厚く薬剤層を形成する塗布工程と、
    　前記バルーンを収縮させ、前記直管部を前記凸条非存在領域において前記バルーン本体部の内面を内側にして折り返して、前記凸条非存在領域が重ね合わされた折り畳み羽根部を形成し、前記折り畳み羽根部を、前記第１側面側から前記凸条の少なくとも一部を覆うように前記直管部の外面に重ねることにより、前記バルーンを折り畳む工程と
    　を有するバルーンカテーテルの製造方法。     a step of preparing a balloon having a longitudinal direction extending from a proximal side to a distal side and a radial direction perpendicular to the longitudinal direction, the balloon having a straight tube portion, a proximal tapered portion located proximal to the straight tube portion, and a distal tapered portion located distal to the straight tube portion, the straight tube portion having a balloon main body portion and a convex streak that protrudes radially outward and extends in the longitudinal direction on an outer surface of the balloon main body portion, the straight tube portion having a convex streak-presenting region and a convex streak-free region formed on the outer surface of the straight tube portion;
    a coating step of coating an outer surface of the straight tube portion with a drug solution while the balloon is inflated, to form a drug layer at a base of a first side surface on one side of the protrusion stripe, the drug layer being thicker than a base of a second side surface on the other side;
    and folding the balloon by deflating the balloon, folding back the straight tube portion at the non-ridge regions with the inner surface of the balloon body portion facing inward to form folded wing portions where the non-ridge regions are overlapped, and overlapping the folded wing portions on the outer surface of the straight tube portion so as to cover at least a portion of the ridges from the first side surface side.
  10. 　前記塗布工程において、前記バルーンを前記長手方向に延びる中心軸を中心に回転させながら、前記直管部の外面に薬液を塗布する請求項９に記載のバルーンカテーテルの製造方法。 The method for manufacturing a balloon catheter according to claim 9, wherein in the coating step, the medicinal liquid is applied to the outer surface of the straight tube portion while the balloon is rotated about a central axis extending in the longitudinal direction.
  11. 　前記塗布工程において、前記直管部の外面に薬液を塗布した後、前記バルーンを前記長手方向に延びる中心軸を中心に回転させる請求項９に記載のバルーンカテーテルの製造方法。 The method for manufacturing a balloon catheter according to claim 9, wherein in the coating step, after the drug solution is applied to the outer surface of the straight tube section, the balloon is rotated around a central axis extending in the longitudinal direction.
  12. 　前記塗布工程において、前記バルーンを回転させながら、前記薬液に含まれる溶媒の少なくとも一部を蒸発させる請求項９に記載のバルーンカテーテルの製造方法。 The method for manufacturing a balloon catheter according to claim 9, wherein in the coating step, at least a portion of the solvent contained in the drug solution is evaporated while rotating the balloon.
PCT/JP2023/036992 2022-11-16 2023-10-12 Balloon for balloon catheter, balloon catheter, and manufacturing method of balloon catheter WO2024106081A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130190725A1 (en) * 2010-07-16 2013-07-25 Abbott Cardiovascular Systems Inc. Medical device having tissue engaging member and method for delivery of a therapeutic agent
JP2018153288A (en) * 2017-03-16 2018-10-04 テルモ株式会社 Manufacturing method and manufacturing apparatus of balloon catheter
JP2021036924A (en) * 2017-12-27 2021-03-11 テルモ株式会社 Balloon catheter
WO2022158100A1 (en) * 2021-01-21 2022-07-28 株式会社カネカ Balloon for balloon catheter

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130190725A1 (en) * 2010-07-16 2013-07-25 Abbott Cardiovascular Systems Inc. Medical device having tissue engaging member and method for delivery of a therapeutic agent
JP2018153288A (en) * 2017-03-16 2018-10-04 テルモ株式会社 Manufacturing method and manufacturing apparatus of balloon catheter
JP2021036924A (en) * 2017-12-27 2021-03-11 テルモ株式会社 Balloon catheter
WO2022158100A1 (en) * 2021-01-21 2022-07-28 株式会社カネカ Balloon for balloon catheter

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