Balloon and balloon catheter

Abstract

To provide a balloon for a catheter and a balloon catheter which is reduced in stuck risk of a blade to a lesion while securing cutting performance.SOLUTION: A balloon 30 is used for a balloon catheter 100, the balloon 30 is provided with one or more cutting blades 40 on the outer peripheral surface of the balloon 30, in parallel with the longitudinal direction of the balloon 30. At one end of each cutting blade 40 in the longitudinal direction, an end forming part 43c is formed to be higher than the end of the cutting blade 40 and to cover a blade tip near the end.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a balloon and a balloon catheter. [Background technology]

[0002] In the treatment of vascular lesions, for example, in percutaneous transluminal coronary angioplasty, balloon catheters are used to expand the lesions in the coronary arteries to improve blood flow. Balloon catheters are also used in percutaneous transluminal angioplasty (PTA) to treat arteriosclerosis occurring in the femoral artery, iliac artery, popliteal artery, below-the-knee artery, etc. of the lower limbs, and in vascular access interventional therapy (VAIVT) to treat stenosis and blockage of the upper limbs' vascular access.

[0003] However, as arteriosclerosis progresses, plaque may develop in the lesion, or the lesion may calcify and become hard. Such lesions may not be able to be expanded inside the blood vessel by the expansion force of the balloon catheter alone. A cutting balloon catheter with a blade on the balloon is known as a device that allows treatment in such cases. A cutting balloon catheter has a blade-like blade on the outer periphery of the balloon, and this blade can crack the calcified area to make it easier to expand the lumen of the lesion. An example of such a balloon catheter with a blade is shown in Patent Document 1.

[0004] The balloon catheter in Patent Document 1 has a balloon made of a material with high elasticity and high rigidity connected to a catheter placed in the vicinity of the lesion in the blood vessel, and the balloon has flexible cutting blades whose number, position, etc. can be changed. The increased flexibility improves catheter tracking and delivery in a tortuous living body, and has the effect of enabling the catheter to be advanced over a guidewire to a lesion in a cardiovascular cavity or the like that is difficult to reach with a low-flexibility catheter, and the lesion can be excised.

[0005] However, the cutting blade disclosed in Patent Document 1 has a risk of getting stuck by the end of the metal blade, which is strongly pierced into lesions such as plaque, calcification, etc., because the metal blade is provided to the end of the longitudinal direction. In addition, there is a problem that the end of the metal blade may come into contact with blood vessels other than the lesion and cause damage when inserting or removing the balloon. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2008-519654 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the present invention has been made to solve the above-mentioned problems, and aims to provide a balloon for a catheter and a balloon catheter that reduce the risk of the blade getting stuck in a lesion while maintaining cutting performance. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, the balloon and balloon catheter according to the present invention employ the following means.

[0009] The balloon according to the present invention is a balloon used in a balloon catheter, One or more cutting blades are provided on the outer circumferential surface of the balloon in parallel with the longitudinal direction of the balloon, The cutting blade is characterized in that an end forming portion is provided at either end in the longitudinal direction of the cutting blade, the end forming portion being formed at the same height as the end of the cutting blade or higher than the end of the cutting blade.

[0010] By providing an end forming portion at either or both ends of the cutting blade in the longitudinal direction, it is possible to prevent the end of the cutting blade from first penetrating into a lesion such as plaque or calcification, thereby reducing the risk of the cutting blade end penetrating into the lesion and getting stuck. It is also possible to prevent the end of the cutting blade from coming into contact with a blood vessel other than the lesion and causing damage when inserting or removing the balloon.

[0011] In the balloon according to the present invention, the end forming portion may be formed so as to cover a part of the cutting tip of the cutting blade.

[0012] Covering the end of the cutting blade can further reduce the possibility that the cutting edge of the cutting blade will first pierce a lesion such as plaque, calcification, etc. Furthermore, since the end of the cutting blade that is most likely to fall off is covered when passing through a curved portion of a blood vessel, the possibility that the end of the cutting blade will fall off from the balloon or base portion can be reduced, and as a result, the possibility that the entire cutting blade will peel off or fall off can be reduced.

[0013] In the balloon according to the present invention, the end forming portion may be formed so as to gradually decrease in height toward the tip. By adopting such a configuration, it is possible to reduce the end forming portion from getting caught in the blood vessel when the balloon is advanced or withdrawn from the blood vessel, and to move the balloon smoothly.

[0014] Furthermore, in the balloon of the present invention, the cutting blade may be attached to a resin base, and the end forming portion may be molded integrally with the base portion. By integrally forming the end forming portion and the base portion, the possibility of the end forming portion itself falling off can be reduced.

[0015] Furthermore, in the balloon according to the present invention, the cutting blade may be formed by dividing it into a plurality of pieces in the longitudinal direction. By dividing the cutting blade into a plurality of pieces, the balloon can be curved more easily, and can be made to more easily follow the curved inside of a blood vessel.

[0016] Furthermore, in the balloon according to the present invention, the cutting blade may be characterized in that metal blades and resin blades are arranged alternately. By using a cutting blade in which metal blades and resin blades are arranged alternately, it is possible to obtain a balloon with high overall flexibility and excellent blood vessel tracking ability due to the flexibility of the resin blade while ensuring the cutting performance of the metal blade.

[0017] Furthermore, the present invention provides a balloon catheter having the above-mentioned balloon, which can provide the above-mentioned effects. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a side view showing a schematic diagram of one embodiment of a balloon catheter 100 according to the present invention. [Diagram 2] FIG. 1 is a side view showing a schematic diagram of a balloon 30 of a balloon catheter 100 according to the present invention. [Diagram 3] FIG. 2 is a side view showing a schematic diagram of a cutting blade 40 used in the balloon catheter 100 according to the present invention. [Figure 4] FIG. 2 is a side view showing a schematic diagram of another embodiment of the cutting blade 40 of the balloon catheter according to the present invention. [Diagram 5] 1 is a side view showing a schematic diagram of a cutting blade 40 of a balloon catheter according to another embodiment of the present invention. FIG. [Figure 6] FIG. 1 is a schematic diagram showing a balloon catheter according to the present invention in use. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of a balloon catheter 100 according to the present invention will be described with reference to the drawings.

[0020] FIG. 1 is a side view showing a balloon catheter 100 according to an embodiment. The balloon catheter 100 according to the present invention mainly includes a catheter shaft 10, a balloon 30, and an operating member 60 provided at the proximal end of the balloon catheter 100. In each drawing, the cutting blade 40 is drawn larger than the actual scale relative to the size of the balloon for ease of illustration. In addition, the description of the balloon catheter 100 includes the description of the balloon 30 according to the present invention, so the description of the balloon will be substituted for the description of the balloon catheter 100. In this embodiment, the description will be given using an RX type (rapid exchange type), but it may be an over-the-wire type.

[0021] 1, the catheter shaft 10 mainly comprises an inner tube 20 and an outer tube 25 provided on the proximal side of the balloon 30. The inner tube 20 is inserted from the tip of the balloon 30 to the proximal side, and communicates with a guidewire port 23 formed on the side of the catheter shaft 10.

[0022] The inner tube 20 has a guidewire lumen 22 inside for passing a guidewire 90 for carrying the balloon 30 of the balloon catheter 100 to the affected area of ​​the patient and for injecting a medicinal solution or the like. Other configurations are not particularly limited. Materials used for the inner tube 20 include, but are not limited to, olefin-based polymers such as polyamide, polyvinyl chloride, polyethylene, polyurethane, polyether block amide copolymer, polyethylene terephthalate, polypropylene, and copolymers of combinations thereof. It is preferable to use thermoplastic resins such as polyamide and polyurethane that have a proven track record in medical applications.

[0023] The outer tube 25 is a tube provided on the proximal side of the balloon 30 and on the outer peripheral side of the inner tube 20. As shown in Fig. 1, an expansion fluid lumen 26 through which an expansion fluid for expanding the balloon flows is formed between the outer tube 25 and the inner tube 20. The expansion fluid lumen 26 communicates with a balloon lumen 35 inside the balloon 30, and the balloon 30 is expanded by the expansion fluid flowing through this expansion fluid lumen 26.

[0024] The balloon 30 is provided at or near the distal end of the catheter shaft 10, and is a hollow member having a balloon lumen 35 inside, and can be expanded by flowing an expansion fluid inside. The balloon 30 may be made of a non-stretchable material or a low-stretchable material. The material of the balloon 30 may be, for example, nylon (registered trademark), polyvinyl chloride, polyethylene, polyurethane, polyether block amide copolymer, polyethylene terephthalate, polypropylene, or other olefin-based polymers, or copolymers made of combinations of these, but is not limited to these. It is preferable to use a thermoplastic resin with a proven track record in medical applications, such as polyamide or polyurethane.

[0025] The balloon 30 and the outer tube 25 may be molded integrally, or may be molded separately and then joined together. The materials used for the balloon 30 and the outer tube 25 may be the same or different.

[0026] As shown in Fig. 2, one or more cutting blades 40 are attached to the outer circumferential surface of the balloon 30. The cutting blades 40 are provided parallel to the longitudinal direction of the balloon 30. The cutting blades 40 have a blade formed on the outer circumferential side, and by expanding the balloon 30 at a site of plaque formed in a blood vessel due to arteriosclerosis or the like or a calcified site in a blood vessel, for example, the blade can make a crack in the plaque or calcified site, making it easier to widen the blood vessel lumen at the lesion site or the like.

[0027] As shown in FIG. 3A, the cutting blade 40 is manufactured by integrally molding the metallic blade 41a with the resin base portion 42 attached to the balloon 30. As shown in FIG. 3B, the metallic blade 41a has a plurality of round holes 44 formed in the portion embedded in the base portion 42. By providing the round holes 44, resin is filled in the round holes 44, so that the metallic blade 41a can be prevented from falling off the base portion 42. Also, as shown in FIG. 3C, instead of the round holes 44, a cutout portion 44a formed so that the bottom side is narrow and the back side is wide may be used. By providing the cutout portion 44a, the metallic blade 41a can be prevented from falling off the base portion 42 and the metallic blade 41a can be easily curved. The base portion 42 is provided with an end forming portion 43 at one or both ends. That is, an end forming portion 443 (43c, 43d) is provided at one or both ends in the longitudinal direction of the cutting blade 40 according to this embodiment. By arranging the end forming parts 43c and 43d at the end of the cutting blade 40, the blade of the cutting blade 40 is prevented from being arranged at the end, and therefore the risk of the end of the cutting blade 40 strongly piercing and getting stuck in a lesion such as plaque or calcification can be prevented. In addition, when the balloon 30 is inserted or removed, the end of the cutting blade 40 can be prevented from contacting and damaging a blood vessel other than the lesion. The end forming part 43 may be formed to be the same height as the blade of the cutting blade 40 or higher than the blade of the cutting blade 40. By forming the end forming part 43 to be the same height as or higher than the blade of the cutting blade 40, the possibility of the end of the cutting blade 40 piercing a lesion such as plaque or calcification can be further reduced. In addition, the possibility of the end of the cutting blade 40 contacting and damaging a blood vessel other than the lesion can be prevented when the balloon 30 is inserted or removed. The shape of the end forming parts 43c and 43d is not particularly limited, and the tip may be formed to be substantially hemispherical like the end forming part 43d. Preferably, the end forming part 43c is formed to be gradually thinner and lower in height toward the tip side.The end forming portion 43c, which is gradually thinner and lower toward the tip side, may be provided at the front and rear ends of the multiple cutting blades 40 arranged in the longitudinal direction. By configuring the tip to be thin in this manner, the end forming portion 43 does not get caught in the blood vessel when the balloon is advanced or withdrawn from the blood vessel, and can be moved smoothly. The end forming portion 43 may also be formed to cover a part of the blade tip of the cutting blade 40. This can reduce the possibility of the cutting blade 40 falling off.

[0028] The cutting blade 40 can be attached to the base 42 by any suitable method, such as, but not limited to, the integral molding described above, adhesion, casting, thermal bonding, mechanical connection, welding, brazing, or other suitable methods. Similarly, the base 42 can be attached to the balloon 30 by any suitable method, such as adhesion, casting, thermal bonding, mechanical connection, welding, brazing, or other suitable methods.

[0029] The number of cutting blades 40 is not particularly limited, and may be one or more. As shown in Fig. 2, a plurality of cutting blades 40 may be provided in the circumferential direction, or a plurality of cutting blades 40 may be provided in the longitudinal direction. Furthermore, as shown in Fig. 4, each cutting blade 40 may be formed in a divided manner. In this way, by forming the cutting blade 40 in a divided manner, flexibility is improved, and blood vessel tracking ability can be improved.

[0030] Furthermore, as shown in FIG. 5, the metal blade 41a and the resin blade 41b may be arranged alternately. Generally, the metal blade 41a is hard and has excellent cutting performance, but has low flexibility in bending and stretching, and it is difficult for the metal blade 41a to follow the inner surface of the blood vessel or to proceed through the blood vessel in a curved blood vessel. If the metal blade 41a is forced to follow the inner surface, there is a possibility that the metal blade 41a may break or peel off from the balloon 30. On the other hand, the resin blade 41b has excellent flexibility and is easy to follow the inner surface of a curved blood vessel and has excellent deliverability. Therefore, by arranging the metal blade 41a and the resin blade 41b alternately, it is possible to ensure the cutting performance of the metal blade 41a as shown in FIG. 6 while ensuring the blood vessel followability due to the flexibility of the resin blade 41b. In addition, by arranging them alternately, the lengths of the metallic blades 41a and the resin blades 41b are shortened, which also makes it easier to follow curved blood vessels. This makes it possible to advance the balloon 30 to positions that are difficult to reach with other cutting balloon catheters with low flexibility, and also improves the ability to follow the inner surface of the blood vessel.

[0031] The lengths of the metallic blade 41a and the resin blade 41b are not particularly limited, but when the metallic blade 41a is formed to be longer than the resin blade 41b, the cutting performance is improved. On the other hand, when the metallic blade 41a is formed to be shorter than the resin blade 41b, the shorter the metallic blade 41a, the easier it is to follow the curvature inside the blood vessel, and the longer the resin blade 41b, the easier it is to follow the curvature inside the blood vessel. Preferably, the length of the metallic blade 41a is 1.0 mm to 40 mm, and the length of the resin blade 41b is 0.5 mm to 18 mm.

[0032] The operating member 60 has an inflation port 61 into which a balloon-expanding fluid is inserted, and the balloon can be inflated by inserting the balloon-expanding fluid from here.

[0033] The balloon catheter 100 thus prepared is used as follows. First, the guidewire 90 is inserted into the lesion. Then, the balloon 30 is advanced over the guidewire 90 and passed through the blood vessel 70 to reach the lesion. Next, an expansion fluid is injected into the balloon lumen 35 via the expansion fluid lumen 26 to expand the balloon 30. This expansion causes the cutting blade 40 to excise the lesion while expanding the blood vessel 70, as shown in FIG. 6, thereby treating the blood vessel 70.

[0034] The present invention is not limited to the above-described embodiments, and may be embodied in various forms within the technical scope of the present invention. [Industrial Applicability]

[0035] As shown in the above-mentioned embodiment, the present invention can be industrially used as a balloon catheter for expanding a lumen. [Explanation of symbols]

[0036] 10...catheter shaft, 20...inner tube, 22...guidewire lumen, 23...guidewire port, 25...outer tube, 26...lumen for inflation fluid, 30...balloon, 35...balloon lumen, 40...cutting blade, 41a...metal blade, 41b...resin blade, 42...base portion, 43...end forming portion, 43c...end forming portion, 43d...end forming portion, 44...notch, 60...operation member, 61...inflation port, 70...blood vessel, 100...balloon catheter

Claims

1. In the balloon used in the balloon catheter, One or more cutting blades are provided on the outer circumferential surface of the balloon in parallel with the longitudinal direction of the balloon, A balloon characterized in that an end forming portion is provided at either end of the cutting blade in the longitudinal direction, the end forming portion being formed at the same height as the end of the cutting blade or higher than the end of the cutting blade.

2. 2. The balloon according to claim 1, wherein the end forming portion is formed so as to cover a part of a cutting tip of a cutting blade.

3. The balloon according to claim 1, wherein the end forming portion is formed so as to gradually decrease in height toward the tip side.

4. 2. The balloon according to claim 1, wherein the cutting blade is attached to a resin base portion, and the end forming portion is molded integrally with the base portion.

5. The balloon according to claim 1 , wherein the cutting blade is formed by dividing the cutting blade into a plurality of parts in the longitudinal direction.

6. The balloon according to claim 1, wherein the cutting blade comprises metal blades and resin blades arranged alternately.

7. A balloon as described in claim 1, characterized in that the cutting blades are positioned at a distance from each other along the longitudinal direction of the balloon.

8. A balloon catheter having a balloon described in any one of claims 1 to 7.

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