Balloon catheter

Abstract

The balloon of a balloon catheter is provided with a protrusion 20 protruding from the outer surface thereof. The protrusion 20 extends in the axial direction of the balloon 13 along the outer surface of the balloon 13. The balloon has a base part 25 and a wing part 26 formed in a deflated state. The base part 25 is a part that extends along the circumferential direction of the balloon and is provided with the protrusion 20 on the outer surface thereof. The wing part 26 is a part extending radially outward of the balloon 13 from a position in the base part 25 different from the protrusion 20 in the circumferential direction of the balloon 13. A distal end side of the wing part 26 in the wing extending direction abuts against the protrusion 20, thereby forming an inner space 30 surrounded by the wing part 26 and the protrusion 20. A drug 40 is stored in the inner space 30.

Description

Balloon catheter CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2024-135287, filed on August 14, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to balloon catheters.

[0003] A balloon catheter has an inflatable and deflated balloon at its distal end. With a balloon catheter, the balloon is introduced in a deflated state to a site narrowed or blocked by a lesion or the like in a blood vessel, and then the balloon is inflated to expand the site.

[0004] Some balloon catheters have linear elements on the outer surface of the balloon that extend in the axial direction of the balloon. The elements protrude from the outer surface of the balloon. When the balloon is inflated at a lesion, the elements penetrate the lesion, creating cracks in the lesion. This makes it easier to dilate the lesion using the cracks.

[0005] Some element-equipped balloon catheters have a drug applied to the outer surface of the balloon. Patent Document 1 also discloses a balloon catheter with a drug applied to the outer surface of the balloon element. With such a balloon catheter, the drug can be delivered to a treatment site within the body by introducing the balloon into the body. The drug can then be transferred to the treatment site by inflating the balloon, thereby enabling treatment of the treatment site.

[0006] International Publication No. 2021 / 132141

[0007] However, simply applying a drug to the outer surface of a balloon or element may result in the drug falling off the balloon or element during delivery to the treatment site, which could prevent the amount of drug required for treatment from being delivered to the treatment site.

[0008] The present disclosure has been made in view of the above circumstances, and has as its main object to provide a balloon catheter that can efficiently deliver a drug to a treatment site within the body.

[0009] In order to solve the above-mentioned problems, a balloon catheter of the first disclosure comprises an inflatable and deflatable balloon, protruding portions that protrude from the outer surface of the balloon and extend axially along the outer surface of the balloon, and a drug provided on at least one of the balloon and the protruding portions, wherein the balloon is formed in its deflated state and has a base portion and wing portions that extend in the axial direction, the base portion extends circumferentially of the balloon and has the protruding portions provided on its outer surface, the wing portions extend radially outward from a position on the base portion that is different in the circumferential direction from that of the protruding portions, and when the extending direction of the wing portions is defined as the extension direction, the tip ends of the wing portions in the extending direction abut against the protruding portions directly or via the drug, thereby forming an inner space surrounded by the wing portions and the protruding portions, and the drug is contained in the inner space.

[0010] According to the first disclosure, the balloon has a base portion and wing portions that are formed in its deflated state. The base portion extends circumferentially of the balloon and has protrusions on its outer surface. The wing portions extend radially outward from a different position on the base portion in the circumferential direction of the balloon than the protrusions. The tip ends of the wing portions in the extending direction abut against the protrusions directly or via a drug, thereby forming an inner space surrounded by the wing portions and the protrusions. A drug is contained in this inner space.

[0011] According to the above configuration, it is possible to prevent the drug from dropping out of the body during delivery of the drug to a treatment site (e.g., a lesion) by introducing the balloon into the body, thereby enabling efficient delivery of the drug to the treatment site inside the body.

[0012] The balloon catheter of the second disclosure is the balloon catheter of the first disclosure, wherein the wing portion has a bent portion that is bent so as to be convex on the side opposite to the internal space side.

[0013] According to the second disclosure, the blade portion has a bent portion that is bent so as to be convex on the side opposite to the inner space side. In this case, the inner space can be made relatively large, and therefore the medicine can be suitably contained in the inner space.

[0014] The balloon catheter of the third disclosure is the same as that of the second disclosure, except that a first drug layer containing the drug is provided on a first surface portion of the wing portion facing the inner space, and a second drug layer containing the drug is provided on a second surface portion of the protruding portion facing the inner space, the first surface portion being formed at the bent portion, and the first drug layer being formed along the bent portion, so that the intermediate portion in the extension direction is separated from the second drug layer.

[0015] According to the third disclosure, the first drug layer and the second drug layer can be provided in a state where they are contained in the inner space. Furthermore, the first drug layer is formed along the bent portion of the wing portion, so that the middle portion of the first drug layer in the extension direction (extension direction of the wing portion) is separated from the second drug layer. In this case, adhesion between the first drug layer and the second drug layer can be suppressed. This can prevent the adhesion between the first drug layer and the second drug layer from creating resistance and hindering the inflation of the balloon. It can also prevent peeling of the first drug layer or the second drug layer when the balloon is inflated.

[0016] A fourth disclosed balloon catheter is the same as any of the first to third disclosures, wherein the balloon has a cylindrical straight tube portion that has the largest diameter when inflated, the protrusion and the wing portions are provided on at least the straight tube portion, and in the straight tube portion, the tip side of the wing portions abuts against the top of the protrusion.

[0017] According to the fourth disclosure, an internal space is formed in the straight tube section of the balloon by the tip side of the blade section abutting against the top of the protrusion. This allows the internal space in the straight tube section to be relatively large. Therefore, the straight tube section can accommodate a large amount of medication in the internal space, making it possible to suitably accommodate medication. Since the straight tube section is the portion that comes into contact with the treatment site (e.g., the lesion) widely when the balloon is inflated, the above configuration can be considered preferable even taking this into consideration.

[0018] The balloon catheter of the fifth disclosure is the balloon of the fourth disclosure, wherein the balloon has a tapered section adjacent to the straight pipe section in the axial direction and whose diameter decreases as it moves away from the straight pipe section, the protrusion and the wing sections are provided across the straight pipe section and the tapered section, the tip sides of the wing sections in the tapered section abut against the side surfaces of the protrusion, and further, the length of the wing sections in the extending direction in the tapered section decreases as it moves away from the straight pipe section, so that the internal space becomes narrower as it moves away from the straight pipe section.

[0019] The tapered portion of the balloon reduces in diameter as it moves away from the straight tube portion. Therefore, in the tapered portion, the length of the wing portions formed in the extending direction when the balloon is deflated is shorter than that in the straight tube portion. Therefore, in the fifth disclosure, in such a tapered portion, the tip side of the wing portions abuts against the side of the protruding portion, thereby forming an internal space. Also, in the fifth disclosure, in the tapered portion, the length of the wing portions in the extending direction shortens as it moves away from the straight tube portion, thereby narrowing the internal space as it moves away from the straight tube portion. In this case, leakage of the drug to the outside from the end (end opening) of the internal space of the tapered portion on the side away from the straight tube portion can be suppressed. This enables more efficient drug delivery.

[0020] The balloon catheter of the sixth disclosure is, in any one of the first to third disclosures, configured to include the wing portion and the protrusion portion, and equipped with an enclosing portion that surrounds the inner space, and a drug layer containing the drug is provided on the inner surface of the enclosing portion facing the inner space, and the drug layer is provided on the inner surface around the entire circumference of the enclosing portion in the enclosing direction.

[0021] According to the sixth disclosure, the drug layer is provided on the inner surface of the enclosing portion around the entire circumference of the enclosing portion in the enclosing direction. For example, if there is a portion of the inner surface of the enclosing portion in the enclosing direction where the drug layer is not provided, peeling of the drug layer may occur from that portion. In this regard, according to the above configuration, there is no portion where the drug layer is not provided around the entire circumference in the enclosing direction, so peeling of the drug layer can be suitably suppressed.

[0022] The balloon catheter of the seventh disclosure is the balloon catheter of any of the first to third disclosures, wherein a first drug layer containing the drug is provided on a first surface of the wing portion facing the inner space, the location where the tip side of the wing portion abuts the protrusion is the wing abutment location, and the first drug layer is thicker on the side opposite the wing abutment location than on the wing abutment location side.

[0023] According to the seventh disclosure, a first drug layer is provided on the first surface of the blade portion facing the inner space. When the drug in the first drug layer flows out of the inner space, it is expected that it will flow out through the point where the tip side of the blade portion abuts the protruding portion (the blade abutment point). Therefore, in the seventh disclosure, in consideration of this point, the thickness of the first drug layer is made larger on the side opposite the blade abutment point than on the blade abutment point side of the first drug layer. In this case, it is possible to prevent the drug in the first drug layer from flowing out of the inner space.

[0024] The balloon catheter of the eighth disclosure is the same as that of the seventh disclosure, except that a second drug layer containing the drug is provided on a second surface of the protruding portion facing the inner space, and the second drug layer is thicker on the side opposite the blade contact point than on the side where the blade contacts.

[0025] According to the eighth disclosure, a second drug layer is provided on the second surface of the protruding portion facing the inner space. The thickness of the second drug layer is greater on the side opposite the blade contact point than on the blade contact point side of the second drug layer. This prevents the drug in the second drug layer from leaking out of the inner space.

[0026] The balloon catheter of the ninth disclosure is the same as that of the eighth disclosure, except that the base portion extends circumferentially toward the wing portion further than the protrusion and has an extension portion that surrounds the inner space together with the wing portion and the protrusion, and a third drug layer containing the drug is provided on a third surface portion of the extension portion that faces the inner space.

[0027] According to the ninth disclosure, a third drug layer is provided on the third surface portion of the extension portion of the base portion facing the inner space. In this case, the third drug layer is provided at a position away from the blade abutment point, so that the drug in the third drug layer can be prevented from leaking out of the inner space. In addition, in this case, the drug in the first drug layer and the second drug layer as well as the drug in the third drug layer are prevented from leaking out of the inner space, so that the drug can be more efficiently delivered to the treatment site.

[0028] The balloon catheter of the tenth disclosure is, in any one of the first to third disclosures, wherein the surface of the wing portion includes a first surface portion facing the inner space and a fourth surface portion not facing the inner space, the first surface portion having a first drug layer containing the drug, and the fourth surface portion having a fourth drug layer containing the drug, and the thickness of the first drug layer is greater than the thickness of the fourth drug layer.

[0029] According to the tenth disclosure, a first drug layer is provided on the first surface of the wing portion facing the inner space, and a fourth drug layer is provided on the fourth surface not facing the inner space. In this case, the first drug layer is provided in the inner space, and the fourth drug layer is provided outside the inner space. Here, it is assumed that the drug in the first drug layer is prevented from falling off during drug delivery, while the drug in the fourth drug layer is likely to fall off. Therefore, in this disclosure, in consideration of this point, the thickness of the first drug layer is made greater than the thickness of the fourth drug layer. This can suitably prevent the drug from falling off during drug delivery.

[0030] The balloon catheter of the eleventh disclosure is any one of the first to third disclosures, wherein the sum of the amount of drug provided on the surface of the wing portion, the amount of drug provided on the surface of the protrusion portion, and the amount of drug provided on the surface of the base portion is the total amount of drug, and the amount of drug contained in the inner space is 50% or more of the total amount of drug.

[0031] According to the eleventh disclosure, the amount of the drug contained in the inner space is 50% or more of the total amount of the drug. In this case, since a large amount of the drug is contained in the inner space, the drug can be delivered to the treatment site more efficiently.

[0032] A twelfth disclosure of the balloon catheter is the same as any one of the first to third disclosures, wherein the protruding portion is provided with a notch portion, and the drug is housed in the notch portion.

[0033] According to the twelfth disclosure, a drug is accommodated in a cutout portion provided in the protruding portion. In this case, it is possible to prevent the drug accommodated in the cutout portion, as well as the drug accommodated in the inner space, from falling out during drug delivery. Furthermore, when the balloon is inflated to make an incision in the lesion with the protruding portion, the drug in the cutout portion can be transferred to the lesion. Therefore, the drug can be delivered deep into the lesion.

[0034] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0023] Figure 1 is a schematic overall side view showing the configuration of a balloon catheter. Figure 2 is a side view showing a balloon and its surrounding configuration in an inflated state, with the balloon and outer tube shown in longitudinal cross section. (a) is a side view showing the balloon and its surrounding configuration in an inflated state, (b) is a cross-sectional view taken along line A-A in (a), and (c) is an enlarged cross-sectional view of the protruding portion in (b). Figure 3 is a transverse cross-sectional view of the straight tube portion of the balloon in a deflated state, taken along line A-A in Figure 3(a). Figure 4 is a transverse cross-sectional view of the proximal tapered portion of the balloon in a deflated state, taken along line B-B in Figure 3(a). Figure 5 is a transverse cross-sectional view of the proximal tapered portion of the balloon in a deflated state, taken along line C-C in Figure 3(a). Figure 6 is an enlarged cross-sectional view of the periphery of the internal space in Figure 4. Figure 7 is an enlarged cross-sectional view of the periphery of the internal space in Figure 5. 10 is a cross-sectional view showing a state in which the inner space is filled with a medicine in another embodiment. FIG. 11 is a view showing a state in which the medicine is contained in a notch provided in the protrusion.

[0035] An embodiment of the present disclosure will be described below with reference to the drawings. This embodiment relates to a balloon catheter for drug delivery. FIG. 1 is a schematic side view showing the overall configuration of the balloon catheter. Note that the drug is not shown in FIG. 1 (this also applies to FIGS. 2 and 3 described below).

[0036] As shown in FIG. 1, the balloon catheter 10 includes a catheter body 11, a hub 12 attached to the proximal end (base end) of the catheter body 11, and a balloon 13 attached to the distal end (tip end) of the catheter body 11.

[0037] The catheter main body 11 includes an outer tube 15 and an inner tube 16 inserted into the outer tube 15. The outer tube 15 is formed into a tubular shape from a resin material. The proximal end of the outer tube 15 is joined to the hub 12, and the distal end of the outer tube 15 is joined to the balloon 13. The inner cavity 15a (see FIG. 2) of the outer tube 15 communicates with the interior of the hub 12 and the interior of the balloon 13. The inner cavity 15a of the outer tube 15 serves as a fluid lumen through which a compressed fluid flows when the balloon 13 is inflated or deflated.

[0038] The inner tube 16 is formed into a tubular shape from a resin material. The proximal end of the inner tube 16 is joined to a midpoint in the axial direction of the outer tube 15. The inner tube 16 also extends distally beyond the outer tube 15, and this extended portion is inserted into the balloon 13. The distal end of the inner tube 16 is joined to the distal end of the balloon 13.

[0039] The inner lumen 16a (see FIG. 2) of the inner tube 16 serves as a guidewire lumen through which a guidewire G is inserted. A proximal end opening 18 of the inner lumen 16a is located midway along the axial direction of the balloon catheter 10. This makes the balloon catheter 10 an RX-type catheter. The proximal end opening 18 may also be located at the distal end of the balloon catheter 10. In that case, the balloon catheter 10 would be an over-the-wire-type catheter.

[0040] Next, the configuration of the balloon 13 will be described with reference to Figures 2 and 3. Figure 2 is a side view showing the balloon 13 and its surrounding configuration in an inflated state, and shows the balloon 13 and outer tube 15 in a longitudinal cross section. Figure 3 (a) is a side view showing the balloon 13 and its surrounding configuration in an inflated state, (b) is a cross-sectional view taken along line A-A in (a), and (c) is a cross-sectional view showing an enlarged view of the protrusion 20 in (b).

[0041] The balloon 13 is made of a thermoplastic resin material, such as polyamide elastomer. As shown in Figures 2, 3(a), and 3(b), the balloon 13 is formed in a cylindrical (tubular) shape with a circular cross section as a whole. The balloon 13 has a proximal leg portion 13a, a proximal tapered portion 13b, a straight tube portion 13c, a distal tapered portion 13d, and a distal leg portion 13e. The portions 13a to 13e of the balloon 13 are arranged in the above order from the proximal side to the distal side.

[0042] The proximal leg portion 13a is joined to the distal end of the outer tube 15. The proximal tapered portion 13b has a tapered shape, increasing in diameter from the distal end of the proximal leg portion 13a toward the distal side. The straight tube portion 13c has a cylindrical shape, extending with a constant diameter from the distal end of the proximal tapered portion 13b toward the distal side. The straight tube portion 13c is the portion whose diameter is largest when the balloon 13 is inflated. The distal tapered portion 13d has a tapered shape, decreasing in diameter from the distal end of the straight tube portion 13c toward the distal side. The distal leg portion 13e is joined to the distal end of the inner tube 16.

[0043] The proximal tapered section 13b and the distal tapered section 13d each correspond to a "tapered section" adjacent to the straight tube section 13c in the axial direction. The proximal tapered section 13b, the straight tube section 13c, and the distal tapered section 13d form an inflation / deflation section that expands and contracts.

[0044] When compressed fluid is supplied to the inside of the balloon 13 through the lumen 15a of the outer tube 15, the balloon 13 is expanded. On the other hand, when negative pressure is applied to the lumen 15a of the outer tube 15 and the compressed fluid is discharged from the inside of the balloon 13, the balloon 13 is deflated.

[0045] A pair of radiography rings 19 are attached to the inner tube 16 on the inside of the balloon 13. The radiography rings 19 are intended to improve the visibility of the balloon 13 under X-ray projection and to facilitate the positioning of the balloon 13 at the target treatment site.

[0046] The balloon 13 has linear protrusions 20 on its outer surface. The protrusions 20 are intended to create cracks in the lesion when the balloon 13 is inflated to dilate the lesion. With this balloon catheter 10, even if the lesion has hardened due to calcification or other reasons, the protrusions 20 can create cracks in the lesion, which can then trigger the lesion to break down and facilitate dilation. Therefore, this balloon catheter 10 is configured as a balloon catheter with a scoring function. The configuration of the protrusions 20 will be described below.

[0047] 2 and 3(a) to 3(c), the protrusion 20 protrudes from the outer surface of the balloon 13 and extends in the axial direction of the balloon 13 along the outer surface of the balloon 13. The protrusion 20 extends across the proximal tapered portion 13b, the straight tube portion 13c, and the distal tapered portion 13d of the balloon 13.

[0048] The protrusions 20 are arranged at predetermined intervals (more specifically, at equal intervals) around the circumference of the balloon 13, and three protrusions 20 are arranged in this embodiment. Each protrusion 20 is made of the same thermoplastic resin material as the balloon 13 and is formed integrally with the balloon 13. Alternatively, each protrusion 20 may be formed separately from the balloon 13 and fixed to the outer surface of the balloon 13 by welding or the like.

[0049] Each protrusion 20 has a cross section (more specifically, a cross section perpendicular to the length of the protrusion 20) that has a mountain-like shape that protrudes outward in the radial direction of the balloon 13 (hereinafter also referred to as the balloon radial direction), specifically a triangular shape. Each protrusion 20 has an apex 21, which is the distal end in the protrusion direction, and a base 22, which is the proximal end in the protrusion direction. The apex 21 corresponds to the outer end of the protrusion 20 in the balloon radial direction, and the base 22 corresponds to the inner end of the protrusion 20 in the balloon radial direction. Each protrusion 20 also has a pair of side surfaces 23, 24 adjacent to each other via the apex 21. The side surfaces 23, 24 are planar and face opposite each other in the circumferential direction of the balloon 13.

[0050] The cross section of the protrusion 20 does not necessarily have to be triangular, and may have other shapes. For example, the cross section of the protrusion 20 may have a quadrangular shape such as a rectangular shape or a trapezoidal shape, or may have a pentagonal or semicircular shape.

[0051] Next, the configuration of the balloon 13 in a deflated state will be described with reference to Figures 4 to 6. Figure 4 is a cross-sectional view of the straight tube portion 13c of the balloon 13 in a deflated state, taken along line A-A in Figure 3(a). Figure 5 is a cross-sectional view of the proximal tapered portion 13b of the balloon 13 in a deflated state, taken along line B-B in Figure 3(a). Figure 6 is a cross-sectional view of the proximal tapered portion 13b of the balloon 13 in a deflated state, taken along line C-C in Figure 3(a).

[0052] Regarding the drawings, when the balloon 13 is in a deflated state, the cross-sections of the proximal tapered portion 13b and the distal tapered portion 13d have the same configuration. Specifically, when the balloon 13 is in a deflated state, the cross-section of the proximal tapered portion 13b at line B-B in FIG. 3(a) (i.e., the cross-section shown in FIG. 5) and the cross-section of the distal tapered portion 13d at line D-D in FIG. 3(a) have the same configuration. Therefore, it can be said that FIG. 5 also shows the cross-section of the distal tapered portion 13d at line D-D in FIG. 3(a). Furthermore, when the balloon 13 is in a deflated state, the cross-section of the proximal tapered portion 13b at line C-C in FIG. 3(a) (i.e., the cross-section shown in FIG. 6) and the cross-section of the distal tapered portion 13d at line E-E in FIG. 3(a) have the same configuration. Therefore, it can be said that FIG. 6 also shows a cross section of the distal tapered portion 13d at the position of line EE in FIG. 3(a).

[0053] 4 to 6, the balloon 13 is formed in its deflated state and has a base portion 25 and wing portions 26 that extend in the axial direction of the balloon 13. The base portion 25 extends in the circumferential direction of the balloon 13 (hereinafter also referred to as the balloon circumferential direction), and has protrusions 20 on its outer surface. The base portion 25 faces the outer peripheral surface of the inner tube 16 in the radial direction of the balloon 13.

[0054] The wing portions 26 are portions that extend in a wing-like shape outward in the balloon radial direction from the base portion 25. The wing portions 26 extend from a different position in the balloon circumferential direction from the protruding portions 20 on the base portion 25. The wing portions 26 extend in the axial direction of the balloon 13 and are formed across the proximal tapered portion 13b, the straight tube portion 13c, and the distal tapered portion 13d of the balloon 13.

[0055] Wing portions 26 are formed by folding portions of balloon 13 so that they protrude radially outward. Wing portions 26 have folds 28 extending in the axial direction of balloon 13 at the tips of the extension direction (hereinafter also referred to as the wing extension direction) extending from base portion 25. Wing portions 26 are formed by folding portions of balloon 13 along folds 28.

[0056] A plurality of wing portions 26 are provided at predetermined intervals (more specifically, equal intervals) around the circumference of the balloon 13. A base portion 25 is provided between adjacent wing portions 26. Adjacent wing portions 26 are connected via the base portion 25. In this case, the wing portions 26 and the base portions 25 are arranged alternately around the circumference of the balloon 13. Furthermore, each wing portion 26 extends from the boundary between adjacent base portions 25 with the wing portion 26 in between.

[0057] The number of blades 26 is the same as the number of protrusions 20. Therefore, in this embodiment, three blades 26 are provided. The blades 26 and the protrusions 20 are arranged alternately in the circumferential direction of the balloon 13. All of the blades 26 are inclined to one side (the same side) in the circumferential direction of the balloon 13, in other words, they are inclined toward the protrusion 20 on that side.

[0058] The tip side of each blade 26 in the blade extension direction abuts against protrusion 20. More specifically, only the tip side of each blade 26 in the blade extension direction abuts against protrusion 20. The tip side of each blade 26 abuts directly against protrusion 20. However, the tip side of each blade 26 may abut against protrusion 20 via chemical agent 40. In other words, chemical agent 40 may be interposed between the tip side of blade 26 and protrusion 20.

[0059] The tip side of each wing 26 abuts against the protrusion 20, thereby forming an inner space 30 surrounded by the wing 26 and the protrusion 20. The inner space 30 is an elongated space extending in the direction of extension of the protrusion 20 and the wing 26 (in other words, the axial direction of the balloon 13). The inner space 30 is formed across the proximal tapered portion 13b, the straight tube portion 13c, and the distal tapered portion 13d of the balloon 13.

[0060] As will be described later, the internal space 30 accommodates a drug 40. Therefore, the internal space 30 serves as a drug accommodation space for accommodating the drug 40. The configuration of the internal space 30 will be described in detail below with reference to Figs. 7 and 8. Fig. 7 is an enlarged cross-sectional view of the periphery of the internal space 30 in Fig. 4. Fig. 8 is an enlarged cross-sectional view of the periphery of the internal space 30 in Fig. 5.

[0061] 7 and 8, the base portion 25 has a first extending portion 31 that extends to one side in the circumferential direction of the balloon (counterclockwise in FIGS. 7 and 8) beyond the protruding portion 20, and a second extending portion 32 that extends to the other side in the circumferential direction of the balloon (clockwise in FIGS. 7 and 8) beyond the protruding portion 20. The first extending portion 31 and the second extending portion 32 have the same length in the circumferential direction of the balloon (extending length).

[0062] The first extending portion 31 extends toward the blade portion 26 that forms the inner space 30 together with the protruding portion 20, and is connected to the blade portion 26. The first extending portion 31 is disposed facing the inner space 30, and surrounds the inner space 30 together with the blade portion 26 and the protruding portion 20. In this case, the blade portion 26, the protruding portion 20, and the first extending portion 31 form a surrounding portion 33 that surrounds the periphery of the inner space 30. The first extending portion 31 corresponds to the "extending portion."

[0063] As described above, the tip side of the blade portion 26 in the blade extension direction abuts against the protrusion 20. In this case, the tip side of the blade portion 26 and the protrusion 20 abut continuously along the extension direction in which the blade portion 26 and the protrusion 20 extend (i.e., the axial direction of the balloon 13). In other words, if the point where the tip side of the blade portion 26 abuts against the protrusion 20 is defined as the blade abutment point 35, then the blade abutment point 35 extends continuously in the extension direction.

[0064] The portion of the blade 26 facing the inner space 30 forms a bent portion 36 that is bent so as to be convex on the side opposite the inner space 30. The bent portion 36 is located on the base end side of the blade abutment point 35 in the blade extension direction of the blade 26. The bent portion 36 has a bent shape that is convex on the side opposite the inner space 30 when viewed in the axial direction of the balloon 13 (in other words, when viewed in a cross section perpendicular to the axial direction of the balloon 13), and more specifically, has a curved shape.

[0065] The length of the blades 26 in the blade extension direction (hereinafter also referred to as extension length) depends on the diameter of the balloon 13 in the inflated state (hereinafter referred to as balloon diameter). Therefore, the extension length of the blades 26 differs between the straight tube portion 13c and each of the tapered portions 13b and 13d of the balloon 13. This point will be explained below.

[0066] First, regarding straight pipe section 13c, the balloon diameter is large in straight pipe section 13c, so the extension length of blade section 26 is long. Also, since the balloon diameter is constant in straight pipe section 13c, the extension length of blade section 26 is also constant.

[0067] 7, in the straight pipe section 13c, the vanes 26 are provided so as to cover the protruding section 20 from the outside in the balloon radial direction. In addition, in the straight pipe section 13c, the tip ends of the vanes 26 in the vane extension direction abut against the apexes 21 of the protruding sections 20, thereby forming an inner space 30. More specifically, in the straight pipe section 13c, the vanes 26 abut against the apexes 21 at points slightly closer to the base end than the tips in the vane extension direction.

[0068] Next, the tapered sections 13b and 13d will be described. In each of the tapered sections 13b and 13d, the balloon diameter is smaller than that of the straight section 13c, so the extension length of the wing sections 26 is shorter than that of the straight section 13c. Furthermore, in each of the tapered sections 13b and 13d, the balloon diameter gradually decreases with increasing distance from the straight section 13c, so the extension length of the wing sections 26 gradually decreases with increasing distance from the straight section 13c (see FIGS. 5 and 6 ). That is, in the proximal tapered section 13b, the extension length of the wing sections 26 gradually decreases from the distal side to the proximal side, while in the distal tapered section 13d, the extension length of the wing sections 26 gradually decreases from the proximal side to the distal side.

[0069] As shown in Figure 8, of the side surfaces 23, 24 of the protrusion 20, the side surface 23 faces the internal space 30, while the side surface 24 does not face the internal space 30. In each of the tapered portions 13b, 13d, the distal ends of the wing portions 26 in the extension direction abut against the side surfaces 23 of the protrusion 20, thereby forming the internal space 30. As described above, in each of the tapered portions 13b, 13d, the extension length of the wing portions 26 gradually decreases with increasing distance from the straight pipe portion 13c, and therefore the internal space 30 gradually narrows with increasing distance from the straight pipe portion 13c (see also Figures 5 and 6). More specifically, in each of the tapered portions 13b, 13d, the area of ​​the cross section of the internal space 30 (a cross section perpendicular to the axial direction of the balloon 13) gradually decreases with increasing distance from the straight pipe portion 13c.

[0070] Here, the balloon catheter 10 has a drug layer 41 containing a drug 40 provided on each of the balloon 13 and the protruding portion 20. This allows the balloon catheter 10 to deliver the drug 40 to a treatment site (e.g., a lesion) within the body by introducing the balloon 13 into the body. The configuration of the drug layer 41 will be described below.

[0071] 7 and 8 , drug layer 41 is provided on surfaces 43 of blade portion 26, surfaces 44 of protrusions 20, and surfaces 45 of base portion 25. Drug 40 contained in drug layer 41 is an anti-restenosis agent that suppresses restenosis after dilation of the lesion by balloon 13. Examples of anti-restenosis agents that can be used include paclitaxel, sirolimus, and everolimus. Drug 40 contained in drug layer 41 may also be a drug other than an anti-restenosis agent, such as a gene therapy drug or a non-gene therapy drug.

[0072] Below, we will explain in order the drug layers 41 provided on the wing portions 26, the protruding portions 20, and the base portion 25. First, we will explain the drug layer 41 provided on the wing portions 26.

[0073] The surface 43 of the blade portion 26 includes an inner surface portion 43a facing the inner space 30 and an outer surface portion 43b not facing the inner space 30. The outer surface portion 43b is the surface 43 excluding the inner surface portion 43a. The inner surface portion 43a is formed in the bent portion 36 of the blade portion 26. The inner surface portion 43a corresponds to the "first surface portion," and the outer surface portion 43b corresponds to the "fourth surface portion."

[0074] Specifically, the surface 43 of the wing 26 includes faces 46, 47 on both sides of the wing 26 in the balloon radial direction (in other words, the thickness direction of the wing 26), and a short arc-shaped surface 48 connecting these faces 46, 47 at the tip in the direction of extension of the wing. Of the faces 46, 47, the face on the inside in the balloon radial direction is the inner surface 46, and the face on the outside in the balloon radial direction is the outer surface 47. Note that the surface 43 of the wing 26 becomes the outer surface of the balloon 13 when the balloon 13 is inflated.

[0075] The inner surface 46 of the blade portion 26 includes the inner surface portion 43a that faces the internal space 30. In the straight pipe portion 13c, a portion of the inner surface 46 is the inner surface portion 43a, and in each of the tapered portions 13b and 13d, the entire inner surface 46 is the inner surface portion 43a. In the straight pipe portion 13c, the surface of the inner surface 46 excluding the inner surface portion 43a is the outer surface portion 43b (more specifically, a portion of the outer surface portion 43b) that does not face the internal space 30.

[0076] A drug layer 41 is provided on each of the inner surface portion 43a and the outer surface portion 43b of the wing portion 26. Hereinafter, the drug layer 41 provided on the inner surface portion 43a will be referred to as drug layer 41a, and the drug layer 41 provided on the outer surface portion 43b will be referred to as drug layer 41b. Drug layer 41a and drug layer 41b are separated by the wing contact point 35. Drug layer 41a corresponds to the "first drug layer," and drug layer 41b corresponds to the "fourth drug layer."

[0077] Drug layer 41a is provided in a state where it is contained in inner space 30. The thickness of drug layer 41a gradually increases from the tip end toward the base end in the blade extension direction of blade portion 26. In other words, the thickness of drug layer 41a gradually increases as it moves away from blade abutment point 35 in the blade extension direction. Drug layer 41a is also formed along bent portion 36 of blade portion 26. Therefore, drug layer 41a has a curved shape that follows bent portion 36.

[0078] Drug layer 41b is provided outside inner space 30 and has a constant thickness. The thickness of drug layer 41b is smaller than the thickness of drug layer 41a. Specifically, the thickness of drug layer 41b is smaller than the minimum thickness of drug layer 41a. Note that the thickness of drug layer 41b does not necessarily have to be smaller than the minimum thickness of drug layer 41a.

[0079] Furthermore, the thickness of drug layer 41b does not necessarily have to be constant, and the thickness of drug layer 41b may vary. Furthermore, if the average thickness of drug layer 41b is smaller than the average thickness of drug layer 41a, then "the thickness of drug layer 41b is smaller than the thickness of drug layer 41a." In other words, if the average thickness of drug layer 41a is greater than the average thickness of drug layer 41b, then "the thickness of drug layer 41a is greater than the thickness of drug layer 41b." The average thickness of drug layer 41a can be calculated by dividing the volume of drug layer 41a by the area (bottom area) of drug layer 41a on inner surface 43a of wing portion 26. The average thickness of drug layer 41b can be calculated by dividing the volume of drug layer 41b by the area (bottom area) of drug layer 41b on outer surface 43b of wing portion 26.

[0080] In straight tube section 13c, drug layers 41a and 41b are provided on inner surfaces 46 of blade sections 26 (see FIG. 7). Specifically, drug layer 41a is provided on inner surface portion 43a of inner surface 46, and drug layer 41b is provided on outer surface portion 43b. Drug layers 41a and 41b are adjacent to each other via blade abutment points 35. Therefore, in straight tube section 13c, thicker drug layer 41a and thinner drug layer 41b are provided on inner surfaces 46 of blade sections 26.

[0081] Next, the drug layer 41 provided on the protrusion 20 will be described.

[0082] Surface 44 of protrusion 20 includes each of side surfaces 23, 24 of protrusion 20. Each of side surfaces 23, 24 of protrusion 20 is provided with a drug layer 41. Hereinafter, drug layer 41 provided on side surface 23 will be referred to as drug layer 41c, and drug layer 41 provided on side surface 24 will be referred to as drug layer 41d. Each of drug layers 41c, 41d is formed to have the same thickness (same thickness relationship). The thickness of each drug layer 41c, 41d increases toward base 22 of protrusion 20, or in other words, decreases toward top 21 of protrusion 20.

[0083] The side surface 23 of the protruding portion 20 includes an inner surface portion 23a facing the internal space 30 and an outer surface portion 23b not facing the internal space 30. In the straight pipe portion 13c, the entire side surface 23 is the inner surface portion 23a (see FIG. 7). In each of the tapered portions 13b and 13d, the side surface 23 includes the inner surface portion 23a and the outer surface portion 23b (see FIG. 8). The inner surface portion 23a corresponds to the "second surface portion."

[0084] Drug layer 41c is provided on each of inner surface portion 23a and outer surface portion 23b. Hereinafter, drug layer 41c provided on inner surface portion 23a will be referred to as drug layer 41e, and drug layer 41c provided on outer surface portion 23b will be referred to as drug layer 41f. Drug layer 41e and drug layer 41f are separated by blade abutment portion 35. Drug layer 41e is provided in a state contained in inner space 30, and drug layer 41f is provided outside inner space 30. Drug layer 41e corresponds to the "second drug layer."

[0085] As described above, the thickness of drug layer 41c increases toward base 22 of protrusion 20. Therefore, the thickness of drug layer 41e and drug layer 41f also increases toward base 22 of protrusion 20. Furthermore, when viewed from blade abutment point 35 as a reference point, the thickness of drug layer 41e increases with increasing distance from blade abutment point 35, and the thickness of drug layer 41f increases with increasing distance from blade abutment point 35.

[0086] Drug layer 41e is provided continuous with drug layer 41a of wing portion 26. Drug layer 41e is continuous with drug layer 41a of wing portion 26 at the end on the blade contact point 35 side (in other words, the end on the apex 21 side of protrusion 20). Specifically, since drug layer 41a of wing portion 26 has a curved shape along bend 36, drug layer 41e and drug layer 41a of wing portion 26 are continuous only at the end on the blade contact point 35 side. As a result, drug layers 41a, 41e are spaced apart from the end on the blade contact point 35 side. Note that the maximum value of the separation dimension between drug layers 41a, 41e (specifically, the separation dimension in the direction perpendicular to side surface 24) is greater than the thickness of wing portion 26.

[0087] Next, the drug layer 41 provided on the base portion 25 will be described.

[0088] The surface 45 of the base portion 25 includes the surface 31a of the first extending portion 31 and the surface 32a of the second extending portion 32. The surface 31a of the first extending portion 31 faces the inner space 30, and the surface 32a of the second extending portion 32 does not face the inner space 30. The surface 31a of the first extending portion 31 corresponds to the "third surface portion." The surface 45 of the base portion 25 is the surface of the outer surface of the base portion 25 on which the protrusion 20 is not provided.

[0089] A drug layer 41 is provided on each of the surface 31a of the first extending portion 31 and the surface 32a of the second extending portion 32. Hereinafter, the drug layer 41 provided on the surface 31a of the first extending portion 31 will be referred to as drug layer 41g, and the drug layer 41 provided on the surface 32a of the second extending portion 32 will be referred to as drug layer 41h. Note that drug layer 41g corresponds to the "third drug layer."

[0090] Drug layer 41g is provided in a state where it is contained in inner space 30. The average thickness of drug layer 41g is greater than the average thickness of drug layer 41a on wing portion 26 and also greater than the average thickness of drug layer 41e on protrusion 20. The average thickness of drug layer 41g is calculated by dividing the volume of drug layer 41g by the area (bottom area) of drug layer 41a on surface 31a of first extension 31. The average thickness of drug layer 41a is calculated by dividing the volume of drug layer 41a by the area (bottom area) of drug layer 41a on inner surface 43a of wing portion 26. The average thickness of drug layer 41e is calculated by dividing the volume of drug layer 41e by the area (bottom area) of drug layer 41e on inner surface 23a of protrusion 20.

[0091] Drug layer 41g is provided continuously with drug layer 41a of wing portion 26 and drug layer 41e of protrusion 20. Therefore, these three drug layers 41a, 41e, 41g are continuous to form a ring when viewed in the axial direction of balloon 13 (in other words, when viewed in a cross section perpendicular to the axial direction of balloon 13). To further explain this point, the three drug layers 41a, 41e, 41g are provided on inner surface 33a of surrounding portion 33 that faces inner space 30. These drug layers 41a, 41e, 41g are provided continuously around the entire circumference of surrounding portion 33 in the surrounding direction (in other words, the circumferential direction) of surrounding portion 33 on inner surface 33a of surrounding portion 33. The inner surface 33a of the surrounding portion 33 includes the inner surface portion 43a (first surface portion) of the blade portion 26, the inner surface portion 23a (second surface portion) of the protrusion portion 20, and the surface 31a (third surface portion) of the base portion 25 (first extension portion 31).

[0092] Drug layer 41h of second extending portion 32 is provided outside inner space 30, and its thickness is smaller than that of drug layer 41g of first extending portion 31. Furthermore, drug layer 41h has a constant thickness, which is the same as that of drug layer 41b of wing portion 26.

[0093] As described above, drug layers 41 (drug layers 41a-41h) are provided on surfaces 43-45 of wing portion 26, protrusion 20, and base portion 25. Each drug layer 41a-41h can be broadly divided into inner drug layers 41a, 41e, and 41g provided in inner space 30 and outer drug layers 41b, 41d, 41f, and 41h provided outside inner space 30. If the total amount of drug layers 41 (i.e., drug 40) provided on surfaces 43-45 of wing portion 26, protrusion 20, and base portion 25 is taken as the total drug amount, the amount of inner drug layers 41a, 41e, and 41g (i.e., drug 40) provided in inner space 30 is set to 50% or more of the total drug amount, more specifically, 60% or more of the total drug amount. The amount of drug 40 refers to, for example, the mass or volume of drug 40.

[0094] Next, a method of using the balloon catheter 10 will be described. Here, a procedure for dilating a lesion occurring in a blood vessel using the balloon catheter 10 will be described.

[0095] First, a guiding catheter is inserted into a sheath introducer inserted into a blood vessel, and the distal end opening of the guiding catheter is introduced to the coronary artery ostium. Next, a guidewire G is inserted into the guiding catheter, and the inserted guidewire G is introduced from the coronary artery ostium to the peripheral site via the lesion.

[0096] Next, the balloon catheter 10 is introduced into the guiding catheter along the guidewire G. After introduction, the balloon 13 is introduced toward the lesion while being pushed and pulled. During this introduction, the balloon 13 is kept in a deflated state. Once the balloon 13 reaches the lesion, the balloon 13 is expanded. This causes the protruding portion 20 to be pressed against the lesion, and the protruding portion 20 makes an incision (crack) in the lesion. This allows the lesion to be destroyed or otherwise expanded outward using the incision as a trigger.

[0097] Furthermore, as the balloon 13 expands, the balloon 13 and the protruding portions 20 are pressed against the lesion, causing the drug 40 (drug layer 41) provided on the balloon 13 and the protruding portions 20 to migrate to the lesion. This makes it possible to treat the lesion with the drug 40. In particular, the drug 40 on the protruding portions 20 migrates to the lesion when an incision is made in the lesion with the protruding portions 20, making it possible to deliver the drug 40 deep to the lesion.

[0098] After the balloon 13 has completed dilating the lesion, the balloon 13 is deflated, and the balloon catheter 10 is then withdrawn from the body in this deflated state, thereby completing the series of operations.

[0099] As described above, the balloon catheter 10 is primarily used to pass through blood vessels and treat blood vessels such as the coronary arteries, femoral arteries, and pulmonary arteries. However, it can also be used in other "tubes" within the body, such as the urinary tract and digestive tract, as well as in "body cavities."

[0100] According to the configuration of this embodiment described above in detail, the following excellent effects can be obtained.

[0101] When the tip end of the wing portion 26 in the direction of extension of the wing abuts against the protrusion 20, an inner space 30 surrounded by the wing portion 26 and the protrusion 20 is formed, and the drug 40 (drug layer 41) is contained in the inner space 30. In this case, by introducing the balloon 13 into the body, the drug 40 can be prevented from falling out of the body during delivery to the lesion inside the body. This allows the drug 40 to be delivered efficiently to the lesion inside the body.

[0102] The blade portion 26 has a bent portion 36 that is bent so as to be convex on the side opposite to the inner space 30. In this case, the inner space 30 can be made relatively large, and therefore the drug 40 (drug layer 41) can be suitably accommodated in the inner space 30.

[0103] A drug layer 41a is provided on the inner surface portion 43a of the wing portion 26 facing the inner space 30, and a drug layer 41e is provided on the inner surface portion 23a of the protruding portion 20 facing the inner space 30. In this case, each drug layer 41a, 41e can be provided while being contained in the inner space 30. Furthermore, the drug layer 41a is formed along the bent portion 36 of the wing portion 26, so that the middle portion of the drug layer 41a in the direction of extension of the wing is separated from the drug layer 41e of the protruding portion 20. In this case, the drug layers 41a, 41e can be prevented from adhering to each other. This prevents the drug layers 41a, 41e from becoming resistant to the adhering of the drug layers 41a, 41e and hindering the inflation of the balloon 13. This also prevents the drug layers 41a, 41e from peeling off when the balloon 13 is inflated.

[0104] In the straight tube section 13c of the balloon 13, the tip side of the wing section 26 abuts against the apex 21 of the protrusion 20, thereby forming an inner space 30. This allows the inner space 30 to be a relatively large space in the straight tube section 13c. Therefore, the straight tube section 13c can accommodate a large amount of the drug 40 in the inner space 30, and can thus accommodate the drug 40 in an appropriate manner. The straight tube section 13c is the portion that comes into contact with the lesion widely when the balloon 13 is inflated, and the above configuration can be considered preferable even in consideration of this point.

[0105] In the tapered portions 13b and 13d of the balloon 13, the tip sides of the wing portions 26 abut against the side surfaces 23 of the protruding portions 20, thereby forming an inner space 30. Furthermore, in the tapered portions 13b and 13d, the extension length of the wing portions 26 becomes shorter as they move away from the straight pipe portion 13c, thereby narrowing the inner space 30 as they move away from the straight pipe portion 13c. In this case, leakage of the drug 40 to the outside from the end (end opening) of the inner space 30 of the tapered portions 13b and 13d that is away from the straight pipe portion 13c can be suppressed. This allows the drug 40 to be delivered more efficiently.

[0106] Drug layer 41 (specifically, drug layers 41a, 41e, and 41g) is provided on inner surface 33a of surrounding portion 33 around the entire circumference in the surrounding direction of surrounding portion 33. In this case, there are no areas where drug layer 41 is not provided (hereinafter referred to as drug-missing areas) around the entire circumference in the surrounding direction, so peeling of drug layer 41 triggered by drug-missing areas can be suitably suppressed.

[0107] When drug 40 in drug layer 41a provided on inner surface portion 43a of blade portion 26 leaks out of internal space 30, it is expected that the leakage will occur through blade abutment point 35 where the tip side of blade portion 26 abuts protrusion 20. In view of this, in the above embodiment, the thickness of drug layer 41a is made greater on the side of drug layer 41a opposite blade abutment point 35 than on the side of drug layer 41a opposite blade abutment point 35. In this case, leakage of drug 40 in drug layer 41a from internal space 30 can be suitably prevented.

[0108] The thickness of drug layer 41e provided on inner surface portion 23a of protrusion 20 is greater on the side of drug layer 41e opposite blade contact point 35 than on the side of drug layer 41e facing blade contact point 35. This makes it possible to suitably prevent drug 40 in drug layer 41e from leaking out of inner space 30.

[0109] A drug layer 41g is provided on the surface 31a of the first extending portion 31 of the base portion 25. In this case, the drug layer 41g is provided at a position away from the blade abutment point 35, which can suitably prevent the drug 40 in the drug layer 41g from leaking out of the internal space 30. In this case, in addition to the drug 40 in the drug layers 41a, 41e of the blade portion 26 and the protruding portion 20, the drug 40 in the drug layer 41g of the base portion 25 (first extending portion 31) is also prevented from leaking out of the internal space 30, which allows the drug 40 to be delivered more efficiently to the affected area in the body.

[0110] Of the surfaces 43 of the wing portion 26, a drug layer 41a is provided on the inner surface portion 43a facing the inner space 30, and a drug layer 41b is provided on the outer surface portion 43b not facing the inner space 30. In this case, the drug layer 41a is provided in the inner space 30, and the drug layer 41b is provided outside the inner space 30. Here, it is assumed that the drug 40 in the drug layer 41a is prevented from falling off during drug delivery, while the drug 40 in the drug layer 41b is more likely to fall off. Therefore, in the above embodiment, in consideration of this, the thickness of the drug layer 41a is made greater than the thickness of the drug layer 41b. This makes it possible to suitably prevent the drug 40 from falling off during drug delivery.

[0111] The total amount of drug 40 is the sum of the amount of drug 40 provided on the surface 43 of the blade portion 26, the amount of drug 40 provided on the surface 44 of the protrusion 20, and the amount of drug 40 provided on the surface 45 of the base portion 25. The amount of drug 40 contained in the inner space 30 is 50% or more of the total amount of drug. In this case, since a large amount of drug 40 is contained in the inner space 30, the drug 40 can be more efficiently delivered to the affected area in the body.

[0112] The present disclosure is not limited to the above-described embodiment, and may be implemented, for example, as follows.

[0113] (1) In a small-diameter balloon 13, the extension length of the blade portions 26 may be short in the straight pipe portion 13c. In such cases, it may be impossible to abut the tip ends of the blade portions 26 in the blade extension direction against the tops 20a of the protruding portions 20 in the straight pipe portion 13c. Therefore, in such cases, it is preferable to abut the tip ends of the blade portions 26 in the blade extension direction against the side surfaces 23 of the protruding portions 20 in the straight pipe portion 13c. In this way, it is possible to form the inner space 30 even when the extension length of the blade portions 26 in the straight pipe portion 13c is short.

[0114] (2) In the above embodiment, the protruding portion 20 is provided across the proximal tapered portion 13b, the straight pipe portion 13c, and the distal tapered portion 13d. However, the protruding portion 20 may be provided only in the straight pipe portion 13c and the distal tapered portion 13d, without being provided only in the proximal tapered portion 13b. In this case, the inner space 30 is formed only in the straight pipe portion 13c and the distal tapered portion 13d. Furthermore, the protruding portion 20 may be provided only in the straight pipe portion 13c. In this case, the inner space 30 is formed only in the straight pipe portion 13c.

[0115] (3) For example, as shown in Fig. 9, the inner space 30 may be filled with the medicine 40. In this case, it is possible to accommodate a large amount of the medicine 40 in the inner space 30.

[0116] (4) For example, the surface roughness of the inner surface portion 43a of the wing portion 26 may be made rougher than the surface roughness of the outer surface portion 43b. In this case, it is easier to form a thick drug layer 41a on the inner surface portion 43a.

[0117] Furthermore, in protrusion 20, the surface roughness of inner surface portion 23a may be rougher than the surface roughness of outer surface portion 23b and the surface roughness of side surface 24. In this case, it becomes easier to form a thick drug layer 41e on inner surface portion 23a.

[0118] Furthermore, in the base portion 25, the surface roughness of the surface 31a of the first extending portion 31 may be made rougher than the surface roughness of the surface 32a of the second extending portion 32. In this case, it becomes easier to form a thick drug layer 41g on the surface 31a of the first extending portion 31.

[0119] The term "surface roughness" refers to the arithmetic mean roughness Ra defined in JIS B0601: 2001. The arithmetic mean roughness Ra is measured in accordance with JIS B0633: 2001, using a measuring instrument defined in JIS B0651: 2001.

[0120] (5) For example, a hydrophilic coating layer may be provided to cover drug layer 41. In this case, drug 40 can be further prevented from falling off during drug delivery. Furthermore, the inner drug layers 41a, 41e, and 41g of drug layer 41 provided in inner space 30 are prevented from falling off. Therefore, a hydrophilic coating layer may be provided only on outer drug layers 41b, 41d, 41f, and 41h of drug layer 41 provided outside inner space 30.

[0121] (6) For example, as shown in FIG. 10( a), the protruding portion 20 may be provided with a cutout portion 51, and the drug 40 may be accommodated in the cutout portion 51. In the example of FIG. 10( a), the protruding portion 20 is provided with a plurality of cutout portions 51 along its length, and each of the cutout portions 51 accommodates a drug 40. With this configuration, not only the drug 40 accommodated in the inner space 30 but also the drug 40 accommodated in the cutout portions 51 can be prevented from falling out during drug delivery. Furthermore, when the balloon 13 is inflated to make an incision in the lesion with the protruding portion 20, the drug 40 in the cutout portions 51 can be transferred to the lesion, allowing the drug 40 to be delivered deep into the lesion.

[0122] Furthermore, in the above configuration, the tip side of the blade portion 26 is in contact with (close contact with) the chemical substance 40 contained in the cutout portion 51. In this case, the space between the blade portion 26 and the inner surface of the cutout portion 51 (in other words, the cutout portion 51) is blocked by the chemical substance 40. This makes it possible to prevent the chemical substance 40 contained in the inner space 30 from leaking out of the inner space 30 through the cutout portion 51.

[0123] Figures 10(b) to (d) show different forms of the cutout portion. In the example of Figure 10(b), cutout portions 52 are provided on the top 21 side and on each of the side surfaces 23 and 24 of the protruding portion 20, and each of the cutout portions 52 contains a drug 40. In the example of Figure 10(c), cutout portions 53 are provided on each of the side surfaces 23 and 24 of the protruding portion 20, and each of the cutout portions 53 contains a drug 40. Note that the cutout portions 52 and 53 in Figures 8(b) and (c) are concave cutout portions.

[0124] In the example of FIG. 10(d), a concave cutout 55 (in other words, a recess) is provided on one side 23 of the side surfaces 23, 24 of the protruding portion 20, and the drug 40 is accommodated in the side surface 23. The other side surface 24 of the protruding portion 20 is provided with a convex portion 56 protruding from the side surface 24. The cutout 55 and the convex portion 56 are disposed at the same position in the longitudinal direction of the protruding portion 20. Furthermore, both the cutout 55 and the convex portion 56 have semicircular cross-sectional shapes. According to the above configuration, when the protruding portion 20 is engaged with the lesion, the convex portion 56 is pressed toward the cutout 55 due to stress from the lesion, thereby pushing out the drug 40 accommodated in the cutout 55. This facilitates the transfer of the drug 40 to the lesion.

[0125] (7) In the above embodiment, a drug layer 41 is provided on both the balloon 13 (base portion 25 and wing portion 26) and the protruding portion 20, but the drug layer 41 may be provided on only one of the balloon 13 and the protruding portion 20.

[0126] Although the present disclosure has been described with reference to the embodiments, it is understood that the present disclosure is not limited to the embodiments or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

[0127] 10...balloon catheter, 13...balloon, 13b...proximal tapered portion as tapered portion, 13c...straight tube portion, 13d...distal tapered portion as tapered portion, 20...protruding portion, 21...top portion, 23...side portion, 23a...inner surface portion as second surface portion, 25...base portion, 26...wing portion, 30...inner space, 31...first extension portion as extension portion, 31a...surface as third surface portion, 33...enclosing portion, 33a...inner surface, 35...wing abutment point, 36...bent portion, 40...drug, 41...drug layer, 41a...drug layer as first drug layer, 41b...drug layer as fourth drug layer, 41e...drug layer as second drug layer, 41g...drug layer as third drug layer, 43a...inner surface portion as first surface portion, 43b...outer surface portion as fourth surface portion.

Claims

1. A balloon catheter comprising: an inflatable and deflatable balloon; protrusions protruding from the outer surface of the balloon and extending axially along the outer surface of the balloon; and a drug provided on at least one of the balloon and the protrusions, wherein the balloon is formed in its deflating state and has a base and wing portions extending in the axial direction, the base portion extending circumferentially of the balloon and having the protrusions provided on its outer surface, the wing portions extending radially outward from a different position in the circumferential direction of the base portion from that of the protrusions, and when the direction in which the wing portions extend is defined as the extension direction, the tip ends of the wing portions in the extension direction abut against the protrusions directly or via the drug, thereby forming an inner space surrounded by the wing portions and the protrusions, and the drug is contained in the inner space.

2. The balloon catheter according to claim 1, wherein the wing portion has a bent portion that is bent so as to be convex on the side opposite to the inner space.

3. A balloon catheter as described in claim 2, wherein a first drug layer containing the drug is provided on a first surface portion of the wing portion facing the inner space, and a second drug layer containing the drug is provided on a second surface portion of the protruding portion facing the inner space, the first surface portion being formed at the bent portion, and the first drug layer is formed along the bent portion, so that an intermediate portion in the extension direction is separated from the second drug layer.

4. A balloon catheter according to any one of claims 1 to 3, wherein the balloon has a cylindrical straight tube portion that has the largest diameter when inflated, the protrusions and the wing portions are provided on at least the straight tube portion, and in the straight tube portion, the tip side of the wing portions abuts against the top of the protrusions.

5. A balloon catheter as described in claim 4, wherein the balloon has a tapered section adjacent to the straight tube section in the axial direction and whose diameter decreases as it moves away from the straight tube section, the protrusion and the wing sections are provided across the straight tube section and the tapered section, the tip sides of the wing sections in the tapered section abut against the side surfaces of the protrusion, and further, the length of the wing sections in the extending direction in the tapered section becomes shorter as it moves away from the straight tube section, so that the internal space becomes narrower as it moves away from the straight tube section.

6. A balloon catheter as described in any one of claims 1 to 3, comprising an enclosing portion that includes the wing portion and the protrusion and surrounds the periphery of the inner space, wherein a drug layer containing the drug is provided on the inner surface of the enclosing portion that faces the inner space, and wherein the drug layer is provided on the inner surface around the entire circumference of the enclosing portion in the enclosing direction.

7. A balloon catheter as claimed in any one of claims 1 to 3, wherein a first drug layer containing the drug is provided on a first surface of the blade portion facing the internal space, the location where the tip side of the blade portion abuts against the protrusion is a blade abutment location, and the first drug layer is thicker on the side opposite the blade abutment location than on the blade abutment location side.

8. A balloon catheter as described in claim 7, wherein a second drug layer containing the drug is provided on a second surface of the protruding portion facing the internal space, and the second drug layer is thicker on the side opposite the blade contact point than on the blade contact point side.

9. A balloon catheter as described in claim 8, wherein the base portion has an extension portion that extends toward the wing portion in the circumferential direction beyond the protrusion portion and surrounds the inner space together with the wing portion and the protrusion portion, and a third drug layer containing the drug is provided on a third surface portion of the extension portion that faces the inner space.

10. A balloon catheter as described in any one of claims 1 to 3, wherein the surface of the wing portion includes a first surface portion facing the inner space and a fourth surface portion not facing the inner space, the first surface portion is provided with a first drug layer containing the drug, and the fourth surface portion is provided with a fourth drug layer containing the drug, and the thickness of the first drug layer is greater than the thickness of the fourth drug layer.

11. A balloon catheter as described in any one of claims 1 to 3, wherein the sum of the amount of drug provided on the surface of the wing portion, the amount of drug provided on the surface of the protrusion portion, and the amount of drug provided on the surface of the base portion is the total amount of drug, and the amount of drug contained in the inner space is 50% or more of the total amount of drug.

12. A balloon catheter according to any one of claims 1 to 3, wherein the protrusion has a notch, and the drug is contained in the notch.

Images