Balloons and balloon catheters

Abstract

To provide a balloon for a catheter and a balloon catheter which is improved in followability of a blood vessel while securing cutting performance.SOLUTION: A balloon 30 used for a balloon catheter 100 is provided with one or more cutting blades 40 on the outer peripheral surface of the balloon 30, in parallel with a longitudinal direction. Each of the cutting blades 40 has metal blades 41a and resin blades 41b which are alternately arranged.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 part of the coronary artery to improve blood flow. Also, in PTA (Percutaneous Transluminal Angioplasty) for treating arteriosclerosis occurring in the femoral artery, iliac artery, popliteal artery, infrapopliteal artery, etc. of the lower extremities, and in VAIVT (Vascular Access Interventional Therapy) for treating stenosis and occlusion of upper limb vascular access, a balloon catheter may also be used.

[0003] However, as arteriosclerosis progresses, plaques may occur in the lesion part, or the lesion part may calcify to form a hard part. Such lesion parts may not be able to be expanded within the blood vessel only by the expansion force of the balloon catheter. As a device that enables treatment of such lesion parts, a cutting balloon catheter having a blade on the balloon is known. The cutting balloon catheter has a blade-shaped blade on the outer periphery of the balloon, and this blade can make a crack in the calcified part to make it easier to expand the lumen of the lesion part and the like. As a balloon catheter having such a blade, there is, for example, one as described 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 ensures flexibility by providing a series of alternating tabs and holes, or openings, arranged along the base of the metal blade. However, because it ultimately forces the metal blade to bend, there is a problem that the metal blade may break, or the metal blade may detach from the connecting member or fall off. [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 improves the ability to follow blood vessels 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 In balloons used in balloon catheters, 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 metal blades and resin blades are arranged alternately in the longitudinal direction.

[0010] The balloon of the present invention has one or more cutting blades on its outer surface, which allows it to crack plaque or calcified areas formed in blood vessels due to arteriosclerosis, etc., making it easier to widen the lumen of lesions and other areas. In this case, the cutting blades consist of alternating metal blades and resin blades, ensuring cutting performance with the metal blades while providing flexibility in the resin blade portion. This ensures overall flexibility and makes the balloon highly adaptable to blood vessels.

[0011] Furthermore, in the balloon according to the present invention, the resin blades may be characterized by being positioned at both ends of the cutting blade. By positioning the resin blades at both ends of the cutting blade, it is prevented that metal blades are positioned on both sides, thereby preventing the risk of the ends of the metal blades strongly penetrating and getting stuck in lesions such as plaque or calcification. In addition, it is possible to prevent the ends of the metal blades from contacting and damaging blood vessels other than the lesion during balloon insertion or removal.

[0012] Furthermore, the balloon according to the present invention may be characterized in that the end of the metal blade is embedded and held within the resin blade. By adopting such a configuration, the risk of the metal blade peeling off or falling out can be reduced.

[0013] Furthermore, in the balloon according to the present invention, the cutting blades may be provided in multiple locations in the circumferential direction, and may have portions on the same circumferential surface where both resin blades and metal blades are arranged. By adopting such a configuration, both metal blades and resin blades are arranged on the outer circumferential surface at the same position in the longitudinal direction, so that by rotating the balloon in the circumferential direction, either a metal blade or a resin blade can be easily selected and positioned on the lesion.

[0014] Furthermore, in the balloon according to the present invention, the cutting blades may be provided in multiple locations in the circumferential direction, and may have portions on the same circumferential surface where both resin blades and metal blades are arranged. By adopting such a configuration, both metal blades and resin blades are arranged on the outer circumferential surface at the same position in the longitudinal direction, so that by rotating the balloon in the circumferential direction, either a metal blade or a resin blade can be easily selected and positioned on the lesion.

[0015] Furthermore, the cutting blades may be provided in multiples in the longitudinal direction as well as in multiples in the circumferential direction, and may be characterized in that no gaps are formed between the multiple cutting blades in the longitudinal direction and the cutting blades on the same circumference. In this way, by ensuring that there are no areas on the same circumference where there are no cutting blades, it is possible to avoid a situation in which the cutting blades do not come into contact with the lesion.

[0016] Furthermore, in the balloon according to the present invention, each of the metal blades or resin blades may be further divided and formed. By adopting such a configuration, flexibility can be further improved and vascular conformability can be enhanced.

[0017] Furthermore, the present invention provides a balloon catheter having the balloon described above. Such a balloon catheter can provide a balloon catheter having the above-described effects.

Brief Description of the Drawings

[0018] [Figure 1] It is a side view schematically showing one embodiment of a balloon catheter 100 according to the present invention. [Figure 2] It is a side view schematically showing the balloon 30 of the balloon catheter 100 according to the present invention. [Figure 3] It is a cross-sectional view of the A-A portion of FIG. 2. [Figure 4] It is a side view schematically showing an embodiment of the cutting blade 40 of the balloon catheter 100 according to the present invention. [Figure 5] It is a side view schematically showing another embodiment of the balloon catheter 100 according to the present invention. [Figure 6] It is a side view schematically showing still another embodiment of the balloon 30 of the balloon catheter 100 according to the present invention. [Figure 7] It is a side view schematically showing still another embodiment of the balloon 30 of the balloon catheter 100 according to the present invention. [Figure 8] It is a schematic diagram showing the usage state of the balloon catheter according to the present invention.

Modes for Carrying Out the Invention

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

[0020] Figure 1 is a schematic side view of a balloon catheter 100 according to an embodiment. Figures 2 and 3 are a side view and a cross-sectional view of the balloon 30 of the balloon catheter 100 according to an embodiment. In each figure, the cutting blade 40 is drawn larger than the actual size of the balloon for easier illustration. The balloon catheter 100 according to the present invention mainly comprises a catheter shaft 10, a balloon 30, and an operating member 60 provided at the proximal end of the balloon catheter 100. Since the description of the balloon catheter 100 also includes the description of the balloon 30 according to the present invention, the description of the balloon will be replaced by the description of the balloon catheter 100. In this embodiment, an RX type (rapid exchange type) is used for the explanation, but an Over-the-wire type may also be used.

[0021] As shown in Figure 1, the catheter shaft 10 mainly comprises an inner tube 20 and an outer tube 25 provided proximal to the balloon 30. The inner tube 20 is inserted proximal to the tip of the balloon 30 and communicates with a guidewire port 23 created on the 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 Figures 2 and 3, the balloon 30 has one (not shown) or more cutting blades 40 attached to its outer surface in the circumferential direction. The cutting blades 40 have a blade on their outer surface, and by expanding the balloon 30 over plaque formed in the blood vessel due to arteriosclerosis, etc., or in areas of calcification within the blood vessel, the blades can create cracks in the plaque or calcified area, making it easier to widen the lumen of the blood vessel in the lesion. In this embodiment, as shown in Figure 2, the cutting blades 40 consist of alternating metal blades 41a and resin blades 41b. Generally, metal blades 41a are hard and have excellent cutting performance, but they have low flexibility in bending or straightening in the direction of the blade tip, making it difficult to make the metal blades 41a follow the inner surface of the blood vessel or to advance inside the blood vessel in curved blood vessels, etc. If one tries to force it to follow, the metal blades 41a may break or detach from the balloon 30. On the other hand, the resin blade 41b has excellent flexibility and high flexibility, making it easy to follow the inner surface of curved blood vessels and providing excellent delivery. Therefore, in this invention, by arranging the metal blade 41a and the resin blade 41b alternately, the cutting performance of the metal blade 41a is ensured while the flexibility of the resin blade 41b ensures the ability to follow the blood vessel. In addition, by arranging them alternately, the length of the metal blade 41a and the resin blade 41b are shortened, which also makes it easier to follow curved blood vessels. As a result, it becomes possible to advance the balloon 30 to positions that are difficult to reach with other cutting balloon catheters that have low flexibility, and the ability to follow the inner surface of blood vessels is also improved.

[0027] As shown in Figure 4A, the cutting blade 40 has multiple metal blades 41a arranged at intervals along its longitudinal direction, and a resin blade 41b is integrally provided with a base portion 42 that is attached to the balloon 30. Furthermore, end portions 43 are provided at both ends of the cutting blade 40. By providing end portions 43 at both ends, it is possible to prevent the resin blade 41b or metal blade 41a from being located at the ends, thereby reducing the possibility of damaging the inside of the blood vessel during balloon movement. In addition, since it is prevented that metal blades 41a are located on both sides, the risk of the ends of the metal blades 41a strongly piercing and getting stuck in lesions such as plaque or calcification can be prevented. As shown in Figure 4B, the cutting blade 40 is manufactured by molding resin so that the metal blades 41a are arranged between the resin blades 41b. Multiple round holes 44 are formed in the portion of the metal blade 41a that is embedded in the base portion 42. By providing this round hole 44, resin is filled into the round hole 44, which prevents the metal blade 41a from falling off the base portion 42. Alternatively, as shown in Figure 4C, instead of the round hole 44, a notch 44a may be used, which is narrower on the bottom side and wider on the back side. By using a notch 44a, the metal blade 41a is prevented from falling off the base portion 42, and the metal blade 41a is made more flexible. In this embodiment, it is made with four metal blades 41a and three resin blades 41b, but the number of these is not particularly limited.

[0028] The number of cutting blades 40 attached to the balloon 30 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 multiple cutting blades may be provided in the longitudinal direction. Preferably, as shown in Figure 3, they may be provided at three locations at the same angle (120°) or at four locations at 90° intervals. The cutting blades 40 are provided parallel to the longitudinal direction of the balloon 30, and it is preferable to form them so that multiple cutting blades 40 are also arranged in the longitudinal direction. Furthermore, when multiple cutting blades are provided in the circumferential direction, as shown in Figure 5, for example, cutting blades 40 with different lengths of metal blades 41a may be arranged so that both blades are positioned at the same circumferential position (for example, B in Figure 5 (where the upper side is the resin blade 41b and the lower side is the metal blade 41a)), with both being the metal blade 41a and the resin blade 41b. By arranging both the metal blade 41a and the resin blade 41b on the circumferential surface at the same position in the longitudinal direction, the balloon 30 can be rotated in the circumferential direction to easily select and position either the metal blade 41a or the resin blade 41b for the lesion. Also, when multiple cutting blades 40 are arranged in the longitudinal direction, as shown in Figure 5, it is preferable to offset them so that the gaps 46 between the cutting blades 40 are not all located on the same circumferential surface. For example, as shown in Figure 5, the gaps 46 may be arranged in a spiral shape, or as shown in Figure 6, they may be arranged in a zigzag shape.

[0029] Furthermore, while the lengths of the metal blade 41a and the resin blade 41b are not particularly limited, making the length of the metal blade 41a longer than that of the resin blade 41b improves cutting performance. On the other hand, making the length of the metal blade 41a shorter than that of the resin blade 41b improves vascular conformability. This is because a shorter metal blade 41a is more able to conform to the curvature within the blood vessel, while a longer resin blade 41b is more able to curve and conform to the blood vessel. Preferably, the length of the metal blade 41a is 1 mm to 40 mm, and the length of the resin blade 41b is 0.5 mm to 18 mm.

[0030] Furthermore, as shown in Figure 4, it is preferable that a portion of the end of the metal blade 41a is positioned within the resin blade 41b. By holding both ends of the metal blade 41a with the resin blade 41b, the possibility of the metal blade 41a peeling off or falling off the base portion 42 can be reduced.

[0031] Alternatively, instead of the ends 43, resin blades 41b may be placed on both ends of the cutting blade 40. By placing resin blades 41b, which have a lower cutting edge than metal blades, on both ends of the cutting blade 40, it is prevented that metal blades 41a are placed on both sides, thereby preventing the risk of the ends of the metal blades 41a strongly penetrating and getting stuck in lesions such as plaque or calcification. In addition, it is possible to prevent the ends of the metal blades 41a from contacting and damaging blood vessels other than the lesion during insertion or removal of the balloon 30.

[0032] Furthermore, each metal blade 41a and resin blade 41b may be formed in sections, as shown in Figure 7. By forming each metal blade 41a and resin blade 41b in sections in this way, flexibility can be further improved, and the ability to follow blood vessels can be enhanced.

[0033] The operating member 60 has an inflation port 61 into which balloon expansion fluid is inserted, and the balloon 30 can be inflated by inserting the balloon expansion fluid through this port.

[0034] 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 from the inflation port 61 through the expansion fluid lumen 26 into the balloon lumen 35 to inflate the balloon 30. As shown in Figure 8, this expansion allows the cutting blade 40 to excise the lesion while expanding the blood vessel 70, thereby treating the blood vessel 70.

[0035] 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]

[0036] As shown in the embodiments described above, it can be used industrially as a balloon catheter for lumen dilation. [Explanation of symbols]

[0037] 10...Catheter shaft, 20...Inner tube, 22...Guide wire lumen, 25...Outer tube, 26...Lumen for expansion fluid, 30...Balloon, 35...Balloon lumen, 40...Cutting blade, 41a...Metal blade, 41b...Resin blade, 60...Operating member, 61...Operating side guide wire lumen, 62...Operating side balloon lumen, 70...Blood vessel, 100...Balloon catheter

Claims

1. In balloons used in balloon catheters, One or more cutting blades are provided on the outer surface of the balloon, parallel to the longitudinal direction of the balloon. The balloon is characterized in that the cutting blade consists of a metal blade, which has a blade on its outer circumference and is hard and has excellent cutting performance, and a resin blade, which has a blade on its outer circumference and is highly flexible and pliable, arranged alternately in the longitudinal direction.

2. The balloon according to claim 1, characterized in that the resin blades are arranged at both ends of the cutting blade.

3. The balloon according to claim 1, characterized in that the end of the metal blade is embedded and held within the resin blade.

4. The balloon according to claim 1, characterized in that the cutting blades are provided in multiple locations in the circumferential direction, and both resin blades and metal blades are arranged on the same circumferential surface.

5. The cutting blades are provided in multiples in the longitudinal direction and also in multiples in the circumferential direction. The balloon according to claim 1, characterized in that multiple cutting blades in the longitudinal direction and the gaps between the cutting blades are not formed on the same circumference.

6. The balloon according to claim 1, characterized in that each of the metal blades or resin blades is further divided and formed.

7. A balloon catheter having a balloon according to any one of claims 1 to 6.

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