Balloon catheter

Abstract

To provide a balloon catheter in which fluid fed into one lumen hardly enters the other lumen, and a bulkhead between the one lumen and the other lumen is hardly damaged.SOLUTION: A balloon catheter includes a shaft 10 extending in a longitudinal direction from a proximal side to a distal side and a plurality of balloons disposed on a distal part of the shaft 10. The shaft 10 includes a first lumen 110 and a second lumen group 200 composed of a plurality of second lumens 120. The shortest distance D1 between the first lumen 110 and the second lumen 120 is greater than the shortest distance D2 between at least one set of adjacent second lumens 120 constituting the second lumen group 200 on a cross section perpendicular to a longitudinal direction of the shaft 10.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] The formation of stenotic areas caused by calcification on the inner walls of blood vessels leads to diseases such as angina pectoris and myocardial infarction. One of the treatments for these conditions is angioplasty, which uses a balloon catheter to expand the stenotic area. Angioplasty is a minimally invasive therapy that does not require open chest surgery like bypass surgery, and is widely used.

[0003] Aortic stenosis is a disease in which the aortic valve becomes hardened due to calcification, making it difficult to open and blocking blood flow. To treat aortic stenosis, a bioprosthetic valve (artificial valve) is placed via open-chest surgery and catheter to replace the hardened aortic valve.

[0004] The placed biological valve deteriorates over time due to calcification, wear, etc. When the placed biological valve deteriorates, it must be replaced. In replacing a biological valve, the placed biological valve is destroyed by applying high pressure to it using a braided balloon catheter or multiple balloon catheters, and a new biological valve is placed on top of the destroyed biological valve.

[0005] As examples of catheters capable of expanding a balloon at high pressure and used for expanding hardened stenotic areas or placing biological valves, Patent Document 1 discloses a balloon catheter having multiple balloon members in which multiple outer balloon members are arranged to surround the outer surface of an inner balloon member, while Patent Document 2 discloses a device having a perfusion balloon with an internal passage and a balloon arranged in the internal passage of the perfusion balloon. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] US Patent Application Publication No. 2012 / 0209375 [Patent Document 2] Special Publication No. 2018-536474 Summary of the Invention [Problem to be solved by the invention]

[0007] The shaft of a catheter having multiple balloons, such as the conventional catheter described above, may have multiple lumens, such as lumens connected to the respective balloons, a lumen through which a guidewire is inserted, etc. When a shaft has multiple lumens, the thickness of the partition between each lumen becomes thin, which causes problems such as a fluid sent into one lumen entering the other lumen, or damage to the partition between one lumen and the other lumen when the shaft is bent or when a highly rigid object such as a guidewire is inserted into one lumen.

[0008] In view of the above circumstances, an object of the present invention is to provide a balloon catheter in which a fluid pumped into one lumen is less likely to enter the other lumen and in which the partition between one lumen and the other lumen is less likely to be damaged. [Means for solving the problem]

[0009] A balloon catheter according to an embodiment of the present invention that can solve the above problems is as follows. [1] A shaft extending longitudinally from a proximal side to a distal side; a plurality of balloons disposed on a distal portion of the shaft; The shaft has a first lumen and a second lumen group consisting of a plurality of second lumens, A balloon catheter, in a cross section perpendicular to the longitudinal direction of the shaft, the shortest distance between the first lumen and the second lumen is greater than the shortest distance between at least one pair of adjacent second lumens that constitute the second lumen group. [2] A balloon catheter as described in [1], wherein, in a cross section perpendicular to the longitudinal direction of the shaft, the shortest distance between the first inner lumen and the second inner lumen is greater than the shortest distance between the second inner lumen and the outer edge of the shaft. [3] A balloon catheter as described in [1] or [2], wherein, in a cross section perpendicular to the longitudinal direction of the shaft, the shortest distance between the first inner lumen and the second inner lumen is greater than the shortest distance between the first inner lumen and the outer edge of the shaft. [4] A balloon catheter described in any of [1] to [3], wherein, in a cross section perpendicular to the longitudinal direction of the shaft, the sum of the cross-sectional areas of the second lumens that constitute the second lumen group is greater than the cross-sectional area of ​​the first lumen. [5] The balloon catheter according to any one of [1] to [4], wherein in a cross section perpendicular to the longitudinal direction of the shaft, the cross-sectional area of ​​the second lumen is smaller than the cross-sectional area of ​​the first lumen. [6] In a cross section perpendicular to the longitudinal direction of the shaft, the shaft has a one-side region that is a region on one side defined by a virtual straight line passing through a centroid of the shaft, and an other-side region that is a region on the other side, The first lumen is disposed in the one side region, The balloon catheter according to any one of [1] to [5], wherein the second lumen group is disposed in the other-side region. [7] The first lumen is a guidewire lumen through which a guidewire is inserted, The balloon catheter according to any one of [1] to [6], wherein the second lumen constituting the second lumen group is an inflation lumen through which fluid supplied to the lumen of the balloon passes, and is connected to each of the lumens of the multiple balloons. [8] further comprising a guidewire tube having an inner cavity communicating with the guidewire lumen; The balloon catheter according to [7], wherein the guidewire tube is disposed in the inner cavity of the balloon. [9] The balloon catheter according to any one of [1] to [8], which is used for expanding an aortic valve, deforming a biological valve placed in the heart, or destroying the biological valve. Effect of the Invention

[0010] According to the balloon catheter, in a cross section perpendicular to the longitudinal direction of the shaft, the shortest distance between the first lumen and the second lumen is greater than the shortest distance between at least one pair of adjacent second lumens constituting the second lumen group, so that the positions where the first lumen is disposed and the positions where the second lumen is disposed can be separated in the shaft, making it possible to make the partition between the first lumen and the second lumen less likely to be damaged and to make it difficult for fluids or objects sent into the first lumen to enter the second lumen. [Brief description of the drawings]

[0011] [Figure 1] 1 illustrates a side view of a balloon catheter according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a side view of the balloon of the balloon catheter shown in FIG. 1. [Diagram 3] FIG. 2 is a cross-sectional view of the balloon catheter shown in FIG. 1 along line III-III. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described below based on the embodiments, but the present invention is not limited to the following embodiments, and can be modified as appropriate within the scope of the above and below, and all of these are included in the technical scope of the present invention. In addition, hatching and component symbols may be omitted in each drawing for convenience, but in such cases, the specification and other drawings should be referred to. Furthermore, the dimensions of various components in the drawings may differ from the actual dimensions, since priority is given to helping understand the features of the present invention.

[0013] A balloon catheter according to an embodiment of the present invention has a shaft extending longitudinally from the proximal side to the distal side and a number of balloons arranged in the distal portion of the shaft, the shaft having a first lumen and a second lumen group composed of a number of second lumen, and in a cross section perpendicular to the longitudinal direction of the shaft, the shortest distance between the first lumen and the second lumen is greater than the shortest distance between at least one pair of adjacent second lumens that make up the second lumen group.

[0014] A balloon catheter according to an embodiment of the present invention will be described below with reference to Figures 1 to 3. Figure 1 is a side view of a balloon catheter according to an embodiment of the present invention, and Figure 2 is a side view of a balloon of the balloon catheter shown in Figure 1. Figure 3 is a cross-sectional view taken along line III-III of the balloon catheter shown in Figure 1, showing a cross-sectional view perpendicular to the longitudinal direction of the shaft.

[0015] As shown in Figures 1 and 2, the balloon catheter 1 has a shaft 10 extending longitudinally from the proximal side to the distal side, and a plurality of balloons 20 arranged in the distal portion of the shaft 10.

[0016] The shaft 10 has a longitudinal direction x1, a radial direction y1 connecting the centroid of the outer edge of the shaft 10 to a point on the outer edge in a cross section perpendicular to the longitudinal direction x1, and a circumferential direction z1 along the outer edge of the shaft 10 in a cross section perpendicular to the longitudinal direction x1. In this specification, the direction toward the user's hand in the longitudinal direction x1 is referred to as the proximal side, and the side opposite the proximal side, i.e., the direction toward the subject of treatment, is referred to as the distal side.

[0017] Members and parts other than the shaft 10 also have longitudinal directions, radial directions, and circumferential directions, which may or may not be the same as the longitudinal direction x1, radial direction y1, and circumferential direction z1 of the shaft 10; however, for ease of understanding, this specification will be described as assuming that all members and parts have the same longitudinal directions, radial directions, and circumferential directions as the longitudinal direction x1, radial direction y1, and circumferential direction z1 of the shaft 10.

[0018] The balloon 20 is connected to the distal portion of the shaft 10. The balloon 20 can be expanded by introducing a fluid through the lumen of the shaft 10, and can be deflated by discharging the fluid. To control the expansion and contraction of the balloon 20, a fluid can be introduced or discharged using an indeflator (a balloon pressurizer). The fluid used may be, for example, saline or a mixture of a contrast agent and saline. The fluid may be a pressurized fluid pressurized by a pump or the like.

[0019] Examples of materials constituting the balloon 20 include polyamide resins such as nylon 11 and nylon 12, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyurethane resins, and thermoplastic elastomers such as polyether block amide copolymers.

[0020] The materials constituting each of the multiple balloons 20 may be different, but are preferably the same. In other words, each of the multiple balloons 20 is preferably made of the same material. By making each of the multiple balloons 20 out of the same material, it becomes possible to make the degree of expansion, hardness, etc. of the balloons 20 approximately the same in the circumferential direction z1 of the balloons 20.

[0021] When the balloons 20 are expanded, the maximum outer diameters of the balloons 20 may be different from each other, but are preferably the same. The maximum outer diameters of the balloons 20 being the same means that the maximum outer diameters of the balloons 20 are approximately the same, specifically, that the maximum outer diameter of one balloon 20 is 90% or more and 110% or less of the maximum outer diameters of all the other balloons 20. When the balloons 20 are expanded, the maximum outer diameters of the balloons 20 are the same, so that the timing of expansion of all the balloons 20 can be easily aligned, and the expansion of the balloons 20 can be easily controlled. Note that when the balloons 20 are expanded, it means that all the balloons 20 are in an expanded state.

[0022] 1 and 2, the multiple balloons 20 preferably include a first balloon 21 and multiple second balloons 22 arranged outside the first balloon 21 and in a line in the circumferential direction of the first balloon 21. In other words, the multiple balloons 20 preferably include the first balloon 21 and multiple second balloons 22, and the multiple second balloons 22 are preferably arranged along the outer periphery of the first balloon 21.

[0023] The number of first balloons 21 may be more than one, but is preferably one. In other words, the balloon catheter 1 preferably has one first balloon 21 and multiple second balloons 22. By having only one first balloon 21, the first balloon 21 is less likely to move inside the multiple second balloons 22 when the balloon 20 is expanded. As a result, the first balloon 21 is more likely to suppress the expansion of the multiple second balloons 22, and the hardness of the balloon 2 is increased, making it easier to increase the expansion force.

[0024] The number of the second balloons 22 is preferably 3 or more, more preferably 4 or more, and even more preferably 5 or more. By setting the lower limit of the number of the second balloons 22 within the above range, the positions of the first balloon 21 and the second balloon 22 are less likely to shift when the balloon 20 is expanded, and the expansion force of the balloon 20 can be increased. In addition, the number of the second balloons 22 is preferably 20 or less, more preferably 12 or less, even more preferably 10 or less, and particularly preferably 8 or less. By setting the upper limit of the number of the second balloons 22 within the above range, the outer diameter of the balloon 20 is less likely to become excessively large, and the minimal invasiveness of the balloon catheter 1 can be improved.

[0025] When the multiple balloons 20 are expanded, the lengths from the distal end 20d of the balloon 20 to the proximal end 20p of the balloon 20 in the longitudinal direction x1 may be the same or different. When the multiple balloons 20 have a first balloon 21 and multiple second balloons 22, the lengths L2 from the distal end 20d of the second balloon 22 to the proximal end 20p of the second balloon 22 in the longitudinal direction x1 may be different, but are preferably the same. The lengths L2 from the distal end 20d to the proximal end 20p of the second balloon 22 in the longitudinal direction x1 being the same means that the lengths L2 of the multiple second balloons 22 in the longitudinal direction x1 are approximately the same, specifically, the length L2 of one second balloon 22 in the longitudinal direction x1 is 90% or more and 110% or less of the lengths L2 of all the other second balloons 22 in the longitudinal direction x1. Since the length L2 in the longitudinal direction x1 of each of the multiple second balloons 22 when the balloon 20 is expanded is the same, it becomes easier to align the timing at which all of the second balloons 22 expand, making it easier to control the expansion of the balloon 20.

[0026] As shown in FIG. 2, the balloon 20 preferably has a straight tube section 203, a proximal taper section 202 located proximal to the straight tube section 203, a proximal sleeve section 201 located proximal to the proximal taper section 202, a distal taper section 204 located distal to the straight tube section 203, and a distal sleeve section 205 located distal to the distal taper section 204.

[0027] The straight tube portion 203 is preferably substantially cylindrical with approximately the same diameter in the longitudinal direction x1, but may have different diameters in the longitudinal direction x1. The proximal taper portion 202 and the distal taper portion 204 are preferably formed into a substantially conical or truncated conical shape with a smaller diameter as they move away from the straight tube portion 203. Since the straight tube portion 203 has the maximum diameter, when the balloon 20 is expanded at a lesion such as a stenosis, the straight tube portion 203 of the balloon 20 can be sufficiently in contact with the lesion, making it easier to treat the lesion, such as expanding it. In addition, since the proximal taper portion 202 and the distal taper portion 204 are reduced in diameter, when the balloon 20 is deflated, the outer diameters of the proximal and distal ends of the balloon 20 can be reduced to reduce the step between the shaft 10 and the balloon 20, making it easier to insert the balloon catheter 1 into a body cavity.

[0028] In the balloon 20, the proximal tapered section 202, the straight tube section 203, and the distal tapered section 204 are sections that expand when a fluid is introduced into the balloon 20, whereas the proximal sleeve section 201 and the distal sleeve section 205 preferably do not expand. By not expanding the proximal sleeve section 201 and the distal sleeve section 205, it is possible to configure at least a portion of the proximal sleeve section 201 and at least a portion of the distal sleeve section 205 to be easily fixed to the shaft 10.

[0029] The shaft 10 has a first lumen 110 and a second lumen group 200 composed of a plurality of second lumens 120. In other words, the shaft 10 has a plurality of lumens, and the plurality of lumens includes the first lumen 110 and a plurality of second lumens 120.

[0030] 1 shows a so-called over-the-wire type balloon catheter 1, which has a guidewire passage from the distal side to the proximal side of the shaft. When the balloon catheter is an over-the-wire type, it is preferable that the inflation lumen and the guidewire lumen extend to a hub located on the proximal side, and that the proximal openings of each lumen are provided in a bifurcated hub.

[0031] The balloon catheter 1 may have a distal shaft 15 and a proximal shaft 16. Alternatively, the distal shaft 15 and the proximal shaft 16 may be separate members, and the proximal end of the distal shaft 15 may be connected to the distal end of the proximal shaft 16 to form the shaft 10 extending from the balloon 20 to the proximal end of the balloon catheter 1. Alternatively, one shaft 10 may extend from the balloon 20 to the proximal end of the balloon catheter 1, and the distal shaft 15 and the proximal shaft 16 may be further composed of multiple tube members.

[0032] The shaft 10 is preferably made of a resin, a metal, or a combination of a resin and a metal. By using a resin as a constituent material of the shaft 10, it is easy to impart flexibility and elasticity to the shaft 10. In addition, by using a metal as a constituent material of the shaft 10, it is possible to improve the deliverability of the balloon catheter 1. Examples of the resin constituting the shaft 10 include polyamide resins, polyester resins, polyurethane resins, polyolefin resins, fluorine resins, vinyl chloride resins, silicone resins, natural rubber, synthetic rubber, and the like. These may be used alone or in combination of two or more. Examples of the metal constituting the shaft 10 include stainless steel such as SUS304 and SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, gold, Ni-Ti alloy, Co-Cr alloy, or a combination thereof. When the shaft 10 is composed of a distal shaft 15 and a proximal shaft 16 that are separate members, the distal shaft 15 may be formed of a resin, and the proximal shaft 16 may be formed of a metal, for example. Additionally, shaft 10 may have a laminated construction of different materials or the same materials.

[0033] The balloon 20 and the shaft 10 can be joined by bonding with an adhesive, welding, attaching a ring-shaped member to the overlapping portion of the end of the balloon 20 and the shaft 10 and crimping the end, etc. Among these, it is preferable that the balloon 20 and the shaft 10 are joined by welding. By joining the balloon 20 and the shaft 10 by welding, the bond between the balloon 20 and the shaft 10 is unlikely to come loose even if the balloon 20 is repeatedly expanded or contracted, and the bond strength can be improved.

[0034] 1, a hub 5 may be provided on the proximal side of the shaft 10. In addition, the hub 5 may be provided with a fluid injection section 6 that is in communication with a flow path for a fluid to be supplied to the inside of the balloon 20.

[0035] The shaft 10 and the hub 5 can be joined by, for example, bonding with an adhesive, welding, or the like. Among these, it is preferable that the shaft 10 and the hub 5 are joined by adhesion. By joining the shaft 10 and the hub 5 by adhesion, the bond strength between the shaft 10 and the hub 5 can be increased and the durability of the balloon catheter 1 can be improved when the shaft 10 and the hub 5 are made of different materials, for example, when the shaft 10 is made of a highly flexible material and the hub 5 is made of a highly rigid material.

[0036] 3, in a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the shortest distance D1 between the first lumen 110 and the second lumen 120 is greater than the shortest distance D2 between at least one pair of adjacent second lumen 120 constituting the second lumen group 200. The shortest distance D1 between the first lumen 110 and the second lumen 120 in the cross section perpendicular to the longitudinal direction x1 of the shaft 10 refers to the length of the shortest straight line among straight lines connecting a point on the outer edge of the first lumen 110 and a point on the outer edge of the second lumen 120. The shortest distance D2 between a pair of adjacent second lumens 120 that constitute the second lumen group 200 in a cross section perpendicular to the longitudinal direction x1 of the shaft 10 refers to the length of the shortest straight line connecting a point on the outer edge of one of the adjacent pair of second lumens 120 to a point on the outer edge of the other of the adjacent pair of second lumens 120 among all the second lumens 120 that constitute the second lumen group 200.

[0037] Since the shortest distance D1 between the first lumen 110 and the second lumen 120 is greater than the shortest distance D2 between at least one pair of adjacent second lumens 120 constituting the second lumen group 200, the distance between the position where the first lumen 110 is disposed and the position where the second lumen 120 is disposed in the shaft 10 can be increased, and the thickness of the partition between the first lumen 110 and the second lumen 120 can be increased. As a result, when the shaft 10 is curved or when an object with high rigidity such as a guide wire is inserted into the first lumen 110 or the second lumen 120, the partition between the first lumen 110 and the second lumen 120 is less likely to be damaged, and also, it is possible to make it difficult for a fluid or an object sent into one of the first lumen 110 and the second lumen 120 to enter the other of the first lumen 110 and the second lumen 120.

[0038] Furthermore, since the shortest distance D1 between the first lumen 110 and the second lumen 120 is greater than the shortest distance D2 between at least one pair of adjacent second lumen 120 constituting the second lumen group 200, the thickness of the partition wall between the pair of adjacent second lumen 120 constituting the second lumen group 200 in the shaft 10 can be reduced. As a result, the rigidity of the shaft 10 on the second lumen group 200 side can be reduced, resulting in a shaft 10 whose second lumen group 200 side is more easily bent.

[0039] In a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the shortest distance D1 between the first lumen 110 and the second lumen 120 is preferably 1.5 times or more, more preferably 2.0 times or more, and even more preferably 2.5 times or more, of the shortest distance D2 between at least one pair of adjacent second lumen 120 constituting the second lumen group 200. By setting the lower limit of the ratio of the shortest distance D1 between the first lumen 110 and the second lumen 120 to the shortest distance D2 between at least one pair of adjacent second lumen 120 constituting the second lumen group 200 within the above range, the partition between the first lumen 110 and the second lumen 120 can be made less susceptible to damage. Furthermore, in a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the shortest distance D1 between the first lumen 110 and the second lumen 120 is preferably 20 times or less, more preferably 10 times or less, and even more preferably 5 times or less, the shortest distance D2 between at least one pair of adjacent second lumens 120 constituting the second lumen group 200. By setting the upper limit of the ratio of the shortest distance D1 between the first lumen 110 and the second lumen 120 to the shortest distance D2 between at least one pair of adjacent second lumens 120 constituting the second lumen group 200 within the above range, it is possible to prevent the outer diameter of the shaft 10 from becoming too large.

[0040] As shown in FIG. 3, in a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the shortest distance D1 between the first lumen 110 and the second lumen 120 is preferably greater than the shortest distance D3 between the second lumen 120 and the outer edge of the shaft 10. The shortest distance D3 between the second lumen 120 and the outer edge of the shaft 10 in a cross section perpendicular to the longitudinal direction x1 of the shaft 10 refers to the length of the shortest straight line among the straight lines connecting a point on the outer edge of the second lumen 120 and a point on the outer edge of the shaft 10. By making the shortest distance D1 between the first lumen 110 and the second lumen 120 greater than the shortest distance D3 between the second lumen 120 and the outer edge of the shaft 10, the thickness of the partition between the first lumen 110 and the second lumen 120 in the shaft 10 can be increased, and the partition between the first lumen 110 and the second lumen 120 can be made less likely to be damaged. In addition, the thickness of the partition between the second inner cavity 120 and the outer edge of the shaft 10 can be reduced, thereby reducing the rigidity of the second inner cavity 120 side of the shaft 10 and making the second inner cavity 120 side of the shaft 10 easier to bend.

[0041] In a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the shortest distance D1 between the first lumen 110 and the second lumen 120 is preferably 1.1 times or more, more preferably 1.2 times or more, and even more preferably 1.3 times or more, of the shortest distance D3 between the second lumen 120 and the outer edge of the shaft 10. By setting the lower limit of the ratio of the shortest distance D1 between the first lumen 110 and the second lumen 120 to the shortest distance D3 between the second lumen 120 and the outer edge of the shaft 10 within the above range, the thickness of the partition between the first lumen 110 and the second lumen 120 can be increased, making it possible to make the partition between the first lumen 110 and the second lumen 120 less likely to be damaged. In addition, in a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the shortest distance D1 between the first lumen 110 and the second lumen 120 is preferably 10 times or less, more preferably 8 times or less, and even more preferably 5 times or less, of the shortest distance D3 between the second lumen 120 and the outer edge of the shaft 10. By setting the upper limit of the ratio of the shortest distance D1 between the first lumen 110 and the second lumen 120 to the shortest distance D3 between the second lumen 120 and the outer edge of the shaft 10 within the above range, it is easy to ensure the thickness of the partition between the second lumen 120 and the outer edge of the shaft 10, and the partition between the second lumen 120 and the outer edge of the shaft 10 is less likely to be damaged when the shaft 10 is bent, etc.

[0042] As shown in FIG. 3, in a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the shortest distance D1 between the first lumen 110 and the second lumen 120 is preferably greater than the shortest distance D4 between the first lumen 110 and the outer edge of the shaft 10. The shortest distance D4 between the first lumen 110 and the outer edge of the shaft 10 in a cross section perpendicular to the longitudinal direction x1 of the shaft 10 refers to the length of the shortest straight line connecting a point on the outer edge of the first lumen 110 and a point on the outer edge of the shaft 10. By making the shortest distance D1 between the first lumen 110 and the second lumen 120 greater than the shortest distance D4 between the first lumen 110 and the outer edge of the shaft 10, the thickness of the partition between the first lumen 110 and the second lumen 120 in the shaft 10 can be increased, and the partition between the first lumen 110 and the second lumen 120 can be made less susceptible to damage.

[0043] In a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the shortest distance D1 between the first lumen 110 and the second lumen 120 is preferably 1.1 times or more, more preferably 1.2 times or more, and even more preferably 1.3 times or more, of the shortest distance D4 between the first lumen 110 and the outer edge of the shaft 10. By setting the lower limit of the ratio of the shortest distance D1 between the first lumen 110 and the second lumen 120 to the shortest distance D4 between the first lumen 110 and the outer edge of the shaft 10 within the above range, the thickness of the partition between the first lumen 110 and the second lumen 120 becomes thicker, and the partition between the first lumen 110 and the second lumen 120 becomes less likely to be damaged. In addition, in a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the shortest distance D1 between the first lumen 110 and the second lumen 120 is preferably 10 times or less, more preferably 8 times or less, and even more preferably 5 times or less, of the shortest distance D4 between the first lumen 110 and the outer edge of the shaft 10. By setting the upper limit of the ratio of the shortest distance D1 between the first lumen 110 and the second lumen 120 to the shortest distance D4 between the first lumen 110 and the outer edge of the shaft 10 within the above range, it is possible to easily ensure the thickness of the partition between the first lumen 110 and the outer edge of the shaft 10. As a result, it is possible to make the partition between the first lumen 110 and the outer edge of the shaft 10 less likely to be damaged when the shaft 10 is bent, etc.

[0044] As shown in FIG. 3, in a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the total cross-sectional area of ​​the second lumens 120 constituting the second lumen group 200 is preferably larger than the cross-sectional area of ​​the first lumen 110. In other words, the total cross-sectional area of ​​all the second lumens 120 in the shaft 10 is preferably larger than the cross-sectional area of ​​one first lumen 110. Since the total cross-sectional area of ​​the second lumens 120 constituting the second lumen group 200 is larger than the cross-sectional area of ​​the first lumen 110, the resin amount of the shaft 10 on the side where the second lumen group 200 exists is smaller than the resin amount of the shaft 10 on the side where the first lumen 110 exists in the cross section perpendicular to the longitudinal direction x1 of the shaft 10. As a result, the rigidity of the side where the second lumen group 200 exists is more likely to be reduced than the side where the first lumen 110 exists, and the second lumen group 200 side of the shaft 10 can be easily bent.

[0045] In a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the total cross-sectional area of ​​the second lumens 120 constituting the second lumen group 200 is preferably 1.1 times or more, more preferably 1.2 times or more, and even more preferably 1.3 times or more, the cross-sectional area of ​​the first lumen 110. By setting the lower limit of the ratio of the total cross-sectional area of ​​the second lumens 120 constituting the second lumen group 200 to the cross-sectional area of ​​the first lumen 110 within the above range, the amount of resin on the second lumen group 200 side of the shaft 10 is less than the amount of resin on the first lumen 110 side of the shaft 10, and the rigidity of the second lumen group 200 side of the shaft 10 is more likely to be lower than that of the first lumen 110 side, making it possible to make the shaft 10 more likely to bend toward the second lumen group 200 side. Furthermore, in a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the total cross-sectional area of ​​the second lumens 120 constituting the second lumen group 200 is preferably 10 times or less, more preferably 8 times or less, and even more preferably 5 times or less, the cross-sectional area of ​​the first lumen 110. By setting the upper limit of the ratio of the total cross-sectional area of ​​the second lumens 120 constituting the second lumen group 200 to the cross-sectional area of ​​the first lumen 110 within the above range, the shaft 10 can be easily bent toward the second lumen group 200 while preventing the outer diameter of the shaft 10 from becoming large, resulting in a minimally invasive balloon catheter 1.

[0046] As shown in FIG. 3, in a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the cross-sectional area of ​​the second lumen 120 is preferably smaller than the cross-sectional area of ​​the first lumen 110. In other words, the cross-sectional area of ​​one second lumen 120 is preferably smaller than the cross-sectional area of ​​one first lumen 110. Since the cross-sectional area of ​​the second lumen 120 is smaller than the cross-sectional area of ​​the first lumen 110, the number of the second lumen 120 constituting the second lumen group 200 can be increased without increasing the outer diameter of the shaft 10. Therefore, when the total cross-sectional area of ​​all the second lumen 120 possessed by the shaft 10 is larger than the cross-sectional area of ​​one first lumen 110, the number of the second lumen 120 constituting the second lumen group 200 can be increased, and the resin amount of the shaft 10 on the side where the second lumen group 200 exists can be reduced more easily than the resin amount of the shaft 10 on the side where the first lumen 110 exists in the cross section perpendicular to the longitudinal direction x1 of the shaft 10. As a result, the rigidity of the side of the shaft 10 where the second lumen group 200 exists tends to decrease, making it possible to make the second lumen group 200 side of the shaft 10 more easily bent.

[0047] In a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the cross-sectional area of ​​the second lumen 120 is preferably 90% or less, more preferably 85% or less, and even more preferably 80% or less of the cross-sectional area of ​​the first lumen 110. By setting the upper limit value of the ratio of the cross-sectional area of ​​the second lumen 120 to the cross-sectional area of ​​the first lumen 110 within the above range, the cross-sectional area of ​​one second lumen 120 can be made smaller than the cross-sectional area of ​​the first lumen 110, and the number of the multiple second lumen 120 constituting the second lumen group 200 can be increased without increasing the outer diameter of the shaft 10. As a result, the amount of resin on the second lumen group 200 side of the shaft 10 becomes smaller than the amount of resin on the first lumen 110 side of the shaft 10, and the second lumen group 200 side of the shaft 10 becomes soft, making it easier to improve flexibility. Furthermore, in a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the cross-sectional area of ​​the second lumen 120 is preferably 10% or more, more preferably 15% or more, and even more preferably 25% or more of the cross-sectional area of ​​the first lumen 110. By setting the lower limit of the ratio of the cross-sectional area of ​​the second lumen 120 to the cross-sectional area of ​​the first lumen 110 within the above range, it becomes easier to ensure a sufficient cross-sectional area of ​​the second lumen 120, and it becomes easier for fluids, articles, etc. to pass through the second lumen 120.

[0048] The multiple second lumens 120 constituting the second lumen group 200 may have different cross-sectional areas, but are preferably the same. The multiple second lumens 120 having the same cross-sectional area means that the multiple second lumens 120 have approximately the same cross-sectional area, specifically, the cross-sectional area of ​​one second lumen 120 is 90% or more and 110% or less of the cross-sectional area of ​​all the other second lumens 120. By having the multiple second lumens 120 have the same cross-sectional area, the speed and amount of fluid passing through each second lumen 120 can be easily made approximately the same, and the timing and degree of expansion of all the balloons 20 connected to the second lumen 120 can be easily controlled.

[0049] As shown in Fig. 3, in a cross section perpendicular to the longitudinal direction x1 of the shaft 10, the shaft 10 has a one-side region A1, which is a region on one side, and an other-side region A2, which is a region on the other side, defined by a virtual straight line l1 passing through the centroid C1 of the shaft 10, and it is preferable that the first lumen 110 is arranged in the one-side region A1, and the second lumen group 200 is arranged in the other-side region A2. In other words, it is preferable that the first lumen 110 is located on one side of the shaft 10, and all the second lumen 120 constituting the second lumen group 200 are located on the other side, in a cross section perpendicular to the longitudinal direction x1 of the shaft 10. By arranging the first lumen 110 in the one-side region A1 of the shaft 10 and arranging the second lumen group 200 in the other-side region A2 of the shaft 10, it is easier to make the other-side region A2 of the shaft 10 more flexible than the one-side region A1 of the shaft 10. As a result, the other-side region A2 side of the shaft 10 is more easily bent than the one-side region A1 side, making it possible to provide a shaft 10 with good flexibility.

[0050] 1 to 3, the first lumen 110 is a guidewire lumen through which a guidewire is inserted, and the second lumen 120 constituting the second lumen group 200 is an inflation lumen through which a fluid supplied to the lumen of the balloon 20 passes, and it is preferable that the first lumen 110 is a guidewire lumen and the second lumen 120 is an inflation lumen, so that the guidewire can be easily inserted into the first lumen 110 which is the guidewire lumen, and the partition between the first lumen 110 and the second lumen 120 is less likely to be damaged when the guidewire is inserted into the first lumen 110.

[0051] 1, it is preferable that the balloon catheter 1 further includes a guidewire tube 40 having an inner cavity communicating with the guidewire lumen, and the guidewire tube 40 is disposed in the inner cavity of the balloon 20. Since the balloon catheter 1 includes the guidewire tube 40 having an inner cavity communicating with the guidewire lumen, it becomes easy to insert the guidewire into the balloon catheter 1, and the balloon catheter 1 can be transported into the body along the guidewire. Furthermore, by inserting the guidewire into the guidewire tube 40, it is possible to prevent the guidewire from damaging the balloon 20, etc.

[0052] Examples of materials constituting the guidewire tube 40 include polyolefin resins such as polyethylene and polypropylene, polyamide resins such as nylon, polyester resins such as PET, aromatic polyetherketone resins such as PEEK, polyetherpolyamide resins, polyurethane resins, polyimide resins, fluororesins such as PTFE, PFA, and ETFE, and synthetic resins such as polyvinyl chloride resins. Among them, the material constituting the guidewire tube 40 is preferably a polyimide resin. When the material constituting the guidewire tube 40 is a polyimide resin, the lubricity of the guidewire tube 40 is improved. Therefore, it becomes easier to insert the guidewire into the lumen of the guidewire tube 40 and feed the balloon catheter 1 into the body along the guidewire. In addition, the guidewire tube 40 may have a multi-layer structure including a braided layer such as a metal braid. When the guidewire tube 40 has a multi-layer structure, the strength of the guidewire tube 40, the lubricity with respect to the guidewire, and the kink resistance can be increased.

[0053] 1, the proximal end of the guidewire tube 40 is preferably connected to the distal end of the shaft 10. When the shaft 10 has a distal shaft 15 and a proximal shaft 16, the proximal end of the guidewire tube 40 is preferably connected to the distal end of the distal shaft 15. By connecting the proximal end of the guidewire tube 40 to the distal end of the shaft 10, the outer diameter of the balloon catheter 1 is unlikely to become large, thereby improving minimal invasiveness.

[0054] The distal end of the balloon catheter 1 is preferably provided with a tip member 60. The tip member 60 may be provided at the distal end of the balloon catheter 1 by being connected to the distal end of the balloon 20 as a separate member from the guidewire tube 40, or the guidewire tube 40 extending distal to the distal end of the balloon 20 may function as the tip member 60.

[0055] As shown in Figures 1 and 2, an X-ray opaque marker 70 may be placed on the guidewire tube 40 inside the balloon 20 at the portion where the balloon 20 is located in the longitudinal axis direction x1 so that the position of the balloon 20 can be confirmed by X-ray fluoroscopy.

[0056] The position on the guidewire tube 40 where the X-ray opaque marker 70 is arranged may be, for example, the position of the midpoint of the length from the distal end 20d of the balloon 20 to the proximal end 20p of the balloon 20, the positions of the proximal end 203p and the distal end 203d of the straight tube portion 203 of the balloon 20, etc. Among them, the position on the guidewire tube 40 where the X-ray opaque marker 70 is arranged is preferably the position of the proximal end 203p and the distal end 203d of the straight tube portion 203 of the balloon 20. By arranging the X-ray opaque marker 70 on the guidewire tube 40 located at the proximal end 203p and the distal end 203d of the straight tube portion 203 of the balloon 20, it becomes easier to confirm the position of the balloon 20. As a result, it is possible to provide a balloon catheter 1 that is easy to apply pressure to a target location.

[0057] When the balloon catheter is an over-the-wire type, it is preferable that the outer wall of the shaft is coated. When the shaft 10 has a distal shaft 15 and a proximal shaft 16, it is preferable that the outer wall of at least one of the distal shaft 15 and the proximal shaft 16 is coated, and it is more preferable that the outer walls of both the distal shaft 15 and the proximal shaft 16 are coated.

[0058] The coating applied to the shaft 10 can be a hydrophilic coating or a hydrophobic coating depending on the purpose, and can be applied by immersing the shaft 10 in a hydrophilic or hydrophobic coating agent, applying a hydrophilic or hydrophobic coating agent to the outer wall of the shaft 10, or covering the outer wall of the shaft 10 with a hydrophilic or hydrophobic coating agent. The coating agent may contain drugs or additives.

[0059] Examples of hydrophilic coating agents include hydrophilic coating agents made of hydrophilic polymers such as polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyvinylpyrrolidone, methyl vinyl ether maleic anhydride copolymer, or any combination thereof.

[0060] Examples of hydrophobic coating agents include polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), perfluoroalkoxyalkane (PFA), silicone oil, hydrophobic urethane resin, carbon coat, diamond coat, diamond-like carbon (DLC) coat, ceramic coat, and substances with low surface free energy terminated with alkyl groups or perfluoroalkyl groups.

[0061] The balloon catheter 1 of the present invention is preferably used for expanding an aortic valve, deforming a biological valve placed in the heart, or destroying a biological valve. Specifically, the balloon catheter 1 of the present invention is preferably used for expanding an aortic valve hardened by calcification or the like, and for deforming or destroying an artificial valve ring of a biological valve to replace a deteriorated biological valve placed in the heart. The balloon catheter 1 of the present invention has a structure having a plurality of balloons 20, since the partition between the first lumen 110 and the second lumen 120 of the shaft 10 is not easily damaged, and fluids or objects fed into the first lumen 110 are not easily allowed to enter the second lumen 120. This makes it easy to expand a hardened aortic valve and deform or destroy a biological valve, which could not be sufficiently expanded by conventional balloon catheters, and can be suitably used. [Explanation of symbols]

[0062] 1: Balloon catheter 5: Hub 6:Fluid injection part 10: Shaft 15: Distal shaft 16: Proximal shaft 20: Balloon 20d: Distal end of balloon 20p: Proximal end of the balloon 201: Proximal sleeve part 201d: Distal end of proximal sleeve 201p: Proximal end of proximal sleeve 202: Proximal taper 202d: Distal end of proximal taper 202p: Proximal end of proximal taper 203: Straight pipe section 203d: Distal end of straight pipe section 203p: Proximal end of straight pipe 204: Distal taper 204d: Distal end of distal taper 204p: Proximal end of distal taper 205: Distal sleeve part 205d: Distal end of distal sleeve 205p: Proximal end of distal sleeve 21: First balloon 22: Second balloon 40: Guidewire tube 50: Guidewire port 60: Tip part 70: Marker 110: 1st lumen 120:Second lumen 200: 2nd lumen group D1: The shortest distance between the first and second lumen D2: The shortest distance between adjacent second lumens D3: The shortest distance between the second bore and the outer edge of the shaft D4: The shortest distance between the first bore and the outer edge of the shaft C1: Centroid of shaft l1: Imaginary line passing through the center of the shaft A1: One-sided area A2: Other side area L2: Length from the distal end of the balloon to the proximal end of the balloon

Claims

1. a shaft extending longitudinally from a proximal side to a distal side; a plurality of balloons disposed on a distal portion of the shaft; The shaft has a first lumen and a second lumen group consisting of a plurality of second lumens, A balloon catheter, in which, in a cross section perpendicular to the longitudinal direction of the shaft, the shortest distance between the first lumen and the second lumen is greater than the shortest distance between at least one pair of adjacent second lumens that constitute the second lumen group.

2. 2. The balloon catheter according to claim 1, wherein in a cross section perpendicular to the longitudinal direction of the shaft, the shortest distance between the first lumen and the second lumen is greater than the shortest distance between the second lumen and an outer edge of the shaft.

3. 2. The balloon catheter according to claim 1, wherein in a cross section perpendicular to the longitudinal direction of the shaft, the shortest distance between the first lumen and the second lumen is greater than the shortest distance between the first lumen and an outer edge of the shaft.

4. 2. The balloon catheter according to claim 1, wherein in a cross section perpendicular to the longitudinal direction of the shaft, a sum of cross-sectional areas of the second lumens constituting the second lumen group is greater than a cross-sectional area of ​​the first lumen.

5. The balloon catheter according to claim 1 , wherein in a cross section perpendicular to the longitudinal direction of the shaft, a cross-sectional area of ​​the second lumen is smaller than a cross-sectional area of ​​the first lumen.

6. In a cross section perpendicular to the longitudinal direction of the shaft, the shaft has a one-side region that is a region on one side defined by a virtual straight line passing through a centroid of the shaft, and an other-side region that is a region on the other side, The first lumen is disposed in the one side region, The balloon catheter according to claim 1 , wherein the second lumen group is disposed in the other-side region.

7. The first lumen is a guidewire lumen through which a guidewire is inserted, 2. The balloon catheter according to claim 1, wherein the second lumen constituting the second lumen group is an inflation lumen through which fluid supplied to the lumen of the balloon passes, and is in communication with each of the lumens of the plurality of balloons.

8. a guidewire tube having an inner lumen communicating with the guidewire lumen; The balloon catheter of claim 7 , wherein the guidewire tube is disposed within the lumen of the balloon.

9. 2. The balloon catheter according to claim 1, which is used for expanding an aortic valve, deforming a biological valve placed in the heart, or destroying the biological valve.

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