Balloons and balloon catheters

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 Art]

[0002] In the treatment of vascular lesions, for example, in Percutaneous Transluminal Coronary Angioplasty, a balloon catheter is used to expand the lesion site in the coronary artery and improve blood flow. Balloon catheters are also sometimes used when performing PTA (Percutaneous Transluminal Angioplasty) for treating arteriosclerosis occurring in the femoral artery, iliac artery, popliteal artery, infrapopliteal artery and other arteries of the lower limbs, and VAIVT (Vascular Access Interventional Therapy) for treating stenosis and occlusion of upper limb vascular access.

[0003] However, when arteriosclerosis progresses, plaques may form in the lesion site, and further the lesion site may calcify to form hard portions. In some cases, such lesion sites cannot be expanded inside the blood vessel only by the expansion force of a balloon catheter. As a device that enables treatment even in such cases, a cutting balloon catheter in which a blade is provided on a balloon is known. A cutting balloon catheter has a blade-shaped blade on the outer periphery of the balloon, and the blade can create a crack in the calcified site to facilitate expansion of the lumen such as the lesion site. Examples of balloon catheters having such a blade include those disclosed in Patent Document 1.

[0004] The balloon catheter described in Patent Document 1 has a balloon made of a high modulus of elasticity or high rigidity attached to a catheter placed near a lesion in a blood vessel, and this balloon has a flexible cutting blade that can change the number and position of the balloons. The increased flexibility improves the traceability and delivery of the catheter within tortuous living tissue, and has the effect of allowing the catheter to be advanced on a guidewire to lesions such as cardiovascular lumen that are difficult to reach with low-flexibility catheters, and to excise the lesion.

[0005] However, the cutting blade described in Patent Document 1 has a metal blade that extends to the longitudinal end, which carries the risk of the end of the metal blade strongly penetrating and getting stuck in lesions such as plaque or calcification. In addition, there was a problem that the end of the metal blade could come into contact with and damage blood vessels other than the lesion during balloon insertion or removal. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Special Publication No. 2008-519654 [Overview of the project] [Problems that the invention aims to solve]

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

[0008] To achieve the aforementioned objectives, 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 surface of the balloon, parallel to the longitudinal direction of the balloon. The cutting blade is characterized in that one of its longitudinal ends is provided with an end-forming portion that is the same height as the end of the cutting blade, or higher than the end of the cutting blade.

[0010] By providing end-forming sections at one or both ends of the cutting blade in the longitudinal direction, it is possible to prevent the cutting edge of the blade from initially piercing lesions such as plaque or calcification, thereby reducing the risk of the cutting edge of the blade piercing and getting stuck in the lesion. Furthermore, it is possible to prevent the cutting edge of the blade from contacting and damaging blood vessels other than the lesion during balloon insertion or removal.

[0011] In the balloon according to the present invention, the end forming portion may be characterized in that it is formed to cover a part of the cutting blade tip.

[0012] By covering the end of the cutting blade, the possibility of the cutting edge initially puncturing lesions such as plaque or calcification can be further reduced. Furthermore, by covering the end of the cutting blade, which is most prone to detachment when passing through curved sections of blood vessels, the possibility of the end of the cutting blade detaching from the balloon or base can be reduced, and as a result, the possibility of the entire cutting blade detaching or falling off can be reduced.

[0013] Furthermore, in the balloon according to the present invention, the end forming portion may be characterized in that its height gradually decreases towards the tip. By adopting such a configuration, the risk of the end forming portion getting caught in the blood vessel when advancing or withdrawing the balloon within the blood vessel can be reduced, allowing for smooth movement.

[0014] Furthermore, in the balloon according to the present invention, the cutting blade may be attached to a resin base, and the end forming portion may be integrally molded 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 characterized by being formed by dividing it into multiple sections in the longitudinal direction. By dividing the cutting blade into multiple sections, the balloon can be made easier to bend, and it can be made easier to follow the curved shape of a blood vessel.

[0016] Furthermore, in the balloon according to the present invention, the cutting blade may be characterized by having metal blades and resin blades arranged alternately. By using a cutting blade in which metal blades and resin blades are arranged alternately, it is possible to ensure the cutting performance of the metal blades while the flexibility of the resin blades provides overall high flexibility and excellent vascular conformability to the balloon.

[0017] Furthermore, the present invention provides a balloon catheter having the aforementioned balloon. Such a balloon catheter can provide the balloon catheter having the aforementioned effects. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic side view showing one embodiment of the balloon catheter 100 according to the present invention. [Figure 2] This is a schematic side view showing the balloon 30 of the balloon catheter 100 according to the present invention. [Figure 3] This is a schematic side view showing a cutting blade 40 used in a balloon catheter 100 according to the present invention. [Figure 4] It is a side view schematically showing another embodiment of the cutting blade 40 for the balloon catheter according to the present invention. [Figure 5] It is a side view schematically showing still another embodiment of the cutting blade 40 for the balloon catheter according to the present invention. [Figure 6] It is a schematic diagram showing a state of use of the balloon catheter according to the present invention. MODE FOR CARRYING OUT THE INVENTION

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

[0020] FIG. 1 is a side view schematically showing the balloon catheter 100 according to the 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 a 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. Further, 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 is replaced with the description of the balloon catheter 100. In the present embodiment, the description is given using an RX type (rapid exchange type), but an Over-the-wire type may also be used.

[0021] As shown in FIG. 1, the catheter shaft 10 mainly includes an inner tube 20 and an outer tube 25 provided on the proximal side of the balloon 30. The inner tube 20 is inserted proximally from the distal end of the balloon 30 and communicates with a guide wire port 23 formed on a side of the catheter shaft 10.

[0022] The inner tube 20 has an internal guidewire lumen 22 for passing a guidewire 90 to guide the balloon 30 of the balloon catheter 100 to the patient's lesion, and for injecting medication or other substances. Other components are not particularly limited. The material used for the inner tube 20 may include, but is not limited to, polyamide, polyvinyl chloride, polyethylene, polyurethane, polyether block amide copolymer, polyethylene terephthalate, polypropylene, or other olefin polymers or combinations thereof. Preferably, thermoplastic resins with a proven track record in medical applications, such as polyamide or polyurethane, are used.

[0023] The outer tube 25 is a tube located proximal to the balloon 30 and on the outer circumference of the inner tube 20. As shown in Figure 1, an expansion fluid lumen 26 is formed between the outer tube 25 and the inner tube 20, through which the expansion fluid for balloon expansion flows. The expansion fluid lumen 26 is in communication with the 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 component having a balloon lumen 35 inside, which 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. As the material of the balloon 30, for example, olefin polymers such as nylon (registered trademark), polyvinyl chloride, polyethylene, polyurethane, polyether block amide copolymer, polyethylene terephthalate, and polypropylene, or copolymers made of combinations thereof, can be used, but are not limited to these. Preferably, thermoplastic resins with a proven track record in medical applications such as polyamide and polyurethane are used.

[0025] The balloon 30 and the outer tube 25 may be molded as a single unit, or they may be molded separately and then joined together. Furthermore, the materials used for the balloon 30 and the outer tube 25 may be the same or different materials.

[0026] As shown in Figure 2, one or more cutting blades 40 are attached to the outer surface of the balloon 30. The cutting blades 40 are arranged parallel to the longitudinal direction of the balloon 30. The outer surface of the cutting blades 40 is formed with a blade, and by expanding the balloon 30 in areas such as plaque formed in blood vessels due to arteriosclerosis or calcified areas within blood vessels, the blade can create cracks in the plaque or calcified areas, making it easier to widen the lumen of the blood vessel in lesions and other areas.

[0027] As shown in Figure 3A, the cutting blade 40 has a metal blade 41a that is a balloon It is integrally molded with the resin base part 42 that is attached to part 30. As shown in Figure 3B, part 41a has multiple circular holes 44 in the portion embedded within the base part 42. A round hole 44 is formed. By providing this round hole 44, resin is embedded in this round hole 44. Therefore, it is possible to prevent the metal blade 41a from falling off the base portion 42. Also, as shown in Figure 3C, instead of the round hole 44, the bottom side is narrower and the back side is wider. The notch 44a may be formed in such a way. By making it a notch 44a, the metal This prevents the blade 41a from falling off the base portion 42, and also prevents the metal blade 41 a can be made more flexible. The base portion 42 has end forming portions on either one or both ends. 43 is provided. That is, the longitudinal side of the cutting blade 40 according to this embodiment At either or both ends in the direction, there is an end forming portion. 43 (43c, 43d) are provided. By positioning the end forming portions 43c and 43d at the ends of the cutting blade 40, This prevents the cutting blade 40 from being positioned at the end, The tip of the cutting blade 40 firmly penetrates the lesion, such as calcification, and gets stuck. This prevents cutting during insertion or removal of balloon 30. This prevents the end of the razor 40 from contacting and damaging blood vessels other than the lesion. The end forming portion 43 is at the same height as the cutting blade 40, or cutting It is preferable to form it so that it is higher than the height of the blade 40. Cutting end portion 43 By forming the cutting blade 40 to be the same height as or higher than the blade height, The possibility of the 40-point tip puncturing lesions such as plaque or calcification can be further reduced. Furthermore, when inserting or removing the balloon 30, the end of the cutting blade 40 may not touch anything other than the lesion. It can prevent contact with and potential damage to blood vessels. Also, the end forming portion 43c, 4 The 3D shape is not particularly limited; the tip can be shaped into a roughly hemispherical shape, as in the end-forming portion 43d. It may be made that way. Preferably, the height gradually decreases toward the tip side, as in the end forming portion 43c. It is best to shape it so that it becomes thinner. The end should be shaped so that the height gradually decreases and the tip becomes thinner. Section 43c is the foremost and rearmost end of a plurality of cutting blades 40 arranged in the longitudinal direction It is best to place it in this area. By making the tip thin in this way, the balloon can advance within the blood vessel. The end forming portion 43 does not get caught inside the blood vessel when it is moved or withdrawn. It can be moved smoothly. Also, the end forming portion 43 is the cutting blade 4 It may be formed to cover a portion of the cutting blade tip. This can reduce the possibility of the D40 dropping out.

[0028] Furthermore, the attachment of the cutting blade 40 to the base portion 42 is not limited to the integral molding described above, but can also be carried out by appropriate methods such as bonding, casting, thermal bonding, mechanical connection, welding, brazing, or other appropriate methods. Similarly, the attachment of the base portion 42 to the balloon 30 can also be carried out by appropriate methods such as bonding, casting, thermal bonding, mechanical connection, welding, brazing, or other appropriate methods.

[0029] Furthermore, the number of cutting blades 40 is not particularly limited; there may be one or multiple cutting blades. As shown in Figure 2, multiple cutting blades 40 may be provided in the circumferential direction or in the longitudinal direction. Moreover, as shown in Figure 4, each cutting blade 40 may be formed in sections. By forming the cutting blades 40 in sections in this way, flexibility can be improved and vascular conformability can be enhanced.

[0030] Furthermore, as shown in Figure 5, metal blades 41a and resin blades 41b may be arranged alternately. Generally, metal blades 41a are hard and have excellent cutting performance, but they have low flexibility in bending and straightening, making it difficult to follow the inner surface of curved blood vessels or to advance them within the vessel. If forced to follow, the metal blade 41a may break or detach from the balloon 30. On the other hand, resin blades 41b have excellent flexibility and high flexibility, making them easy to follow the inner surface of curved blood vessels and providing excellent delivery. Therefore, by arranging metal blades 41a and resin blades 41b alternately, as shown in Figure 6, the cutting performance of the metal blade 41a can be ensured while the flexibility of the resin blade 41b ensures the ability to follow the blood vessel. Furthermore, by arranging them alternately, the lengths of the metal blade 41a and the resin blade 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 that have low flexibility, and also improves its ability to follow the inner surface of blood vessels.

[0031] The lengths of the metal blade 41a and the resin blade 41b are not particularly limited, but the cutting performance is improved when the length of the metal blade 41a is longer than that of the resin blade 41b. On the other hand, when the length of the metal blade 41a is shorter than that of the resin blade 41b, the shorter metal blade 41a is able to follow the curvature inside the blood vessel more easily, and the longer resin blade 41b is able to curve and follow the inside of the blood vessel more easily. Preferably, the length of the metal 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 balloon expansion fluid is inserted, and the balloon can be inflated by inserting the balloon expansion fluid through this port.

[0033] As described above, the fabricated balloon catheter 100 is used as follows. First, the guidewire 90 is inserted into the lesion. Then, the balloon 30 is advanced along the guidewire 90 and passed through the blood vessel 70 to reach the lesion. Next, the expansion fluid is injected into the balloon lumen 35 via the expansion fluid lumen 26 to inflate the balloon 30. As shown in Figure 6, this expansion allows the cutting blade 40 to excise the lesion while expanding the blood vessel 70, thereby treating the blood vessel 70.

[0034] It should be noted that the present invention is not limited in any way to the embodiments described above, and can be implemented in various forms as long as they fall within the technical scope of the present invention. [Industrial applicability]

[0035] As shown in the embodiments described above, it can be used industrially as a balloon catheter for lumen dilation. [Explanation of Symbols]

[0036] 10...Catheter shaft, 20...Inner tube, 22...Guide wire lumen, 23...Guide wire port, 25...Outer tube, 26...Lumen for expansion fluid, 30...Balloon, 35...Balloon lumen, 40...Cutting blade, 41a...Metal blade, 41b...Resin blade, 42...Base section, 43...End forming section, 43c...End forming section, 43d...End forming section, 44...Notch, 60...Operating member, 61...Inflation port, 70...Blood vessel, 100...Balloon catheter

Claims

1. In balloons used in balloon catheters, On the outer surface of the balloon, one or more metal cutting blades are provided on a resin base parallel to the longitudinal direction of the balloon. A balloon characterized in that an end forming portion, which is formed higher than the height of the cutting blade and is made of a resin of a different material than the cutting blade, is provided at either end or both ends in the longitudinal direction of the cutting blade.

2. The balloon according to claim 1, characterized in that the end forming portion is formed to cover a part of the cutting blade tip.

3. The balloon according to claim 1, characterized in that the end forming portion is formed such that its height gradually decreases toward the tip.

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

5. The balloon according to claim 1, characterized in that the cutting blade is formed by dividing it into multiple parts in the longitudinal direction.

6. The balloon according to claim 1, characterized in that the cutting blade has metal blades and resin blades arranged alternately.

7. The balloon according to claim 1, characterized in that the cutting blades are arranged at intervals along the longitudinal direction of the balloon.

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

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