Balloon catheter

Abstract

To provide a balloon catheter in which the shaft is flexible and easily follows an in-vivo lumen, and can be easily inserted through an in-vivo lumen.　This balloon catheter has a shaft (10) that extends in the longitudinal direction from the proximal side to the distal side, and a plurality of balloons that are disposed on the distal part of the shaft (10). The shaft (10) is provided with an inner cylindrical member (130) that has a lumen, and a cylindrical member group (400) constituted from a plurality of outer cylindrical members (140) that are disposed on the outer side of the inner cylindrical member (130) so as to be arranged side by side in the circumferential direction of the inner cylindrical member (130) and that have a lumen. In a cross-section perpendicular to the longitudinal direction, the shaft (10) has a portion in which the distance (D10) between the center (C410) of a first outer cylindrical member (410) and the center (C420) of a second outer cylindrical member (420) is greater than the distance (D11) between the center (C410) of the first outer cylindrical member (410) and the center (C430) of a third outer cylindrical member (430).

Description

Balloon catheter

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

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

[0003] Aortic stenosis is a condition in which the aortic valve becomes hardened due to calcification, making it difficult to open and obstructing blood flow. Treatment for aortic stenosis involves surgical open-chest surgery and catheter placement to replace the hardened aortic valve with a biological valve (artificial valve).

[0004] An implanted bioprosthetic valve deteriorates over time due to calcification, wear, and other factors. When an implanted bioprosthetic valve deteriorates, it must be replaced. One procedure under consideration for replacing a bioprosthetic valve involves applying high pressure to the implanted bioprosthetic valve using a braided balloon catheter or multiple balloon catheters, deforming or destroying it, expanding the valve lumen, and then implanting a new bioprosthetic valve inside the deformed or destroyed bioprosthetic valve using techniques such as transcatheter aortic valve replacement.

[0005] As examples of catheters capable of expanding a balloon at high pressure, which are used to expand hardened stenotic areas or place biological valves, Patent Document 1 discloses a balloon catheter having multiple balloon members, with multiple outer balloon members 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.

[0006] US Patent Application Publication No. 2012 / 0209375 JP 2018-536474 A

[0007] The shaft of a catheter having multiple balloons, such as the conventional catheters described in Patent Documents 1 and 2, may have multiple lumens, such as inflation lumens connected to each balloon and through which fluid supplied to the balloon lumen passes, and a guidewire lumen through which a guidewire is inserted. When a shaft has multiple lumens, the rigidity of the shaft tends to increase due to the presence of partitions between the lumens and the increase in the outer diameter of the shaft. High shaft rigidity makes the shaft difficult to bend, preventing it from adequately conforming to curved lumens in the body, such as blood vessels, and creating the risk of physical irritation, such as injury, to the walls of the body lumen, making it difficult to insert.

[0008] In view of the above circumstances, an object of the present invention is to provide a balloon catheter having a flexible shaft that can easily conform to a lumen in a living body and can be easily inserted into a lumen in a living body.

[0009] The balloon catheter according to an embodiment of the present invention, which has solved the above-mentioned problems, is as follows: [1] A balloon catheter including a shaft extending longitudinally from the proximal side to the distal side, and a plurality of balloons disposed in a distal portion of the shaft, wherein the shaft includes an inner cylindrical member having a lumen, and a cylindrical member group including a plurality of outer cylindrical members, each having a lumen, arranged circumferentially around the inner cylindrical member and arranged side by side around the inner cylindrical member, wherein, in a cross section perpendicular to the longitudinal direction, the cylindrical member group includes a first outer cylindrical member, a second outer cylindrical member arranged adjacent to the first outer cylindrical member in the circumferential direction of the inner cylindrical member, and a third outer cylindrical member arranged adjacent to the first outer cylindrical member in the circumferential direction of the inner cylindrical member and on the opposite side of the second outer cylindrical member, [2] The balloon catheter according to [1], wherein, in a cross section perpendicular to the longitudinal direction, the shaft has a portion where the distance between the center of the first outer cylindrical member and the center of the second outer cylindrical member is greater than the distance between the center of the first outer cylindrical member and the center of the third outer cylindrical member. [2] The balloon catheter according to [1], wherein the shaft has a distal region that is a region on the distal side and a proximal region that is a region located proximal to the distal region, and in a cross section perpendicular to the longitudinal direction in the proximal region, the distance between the center of the first outer cylindrical member and the center of the second outer cylindrical member is greater than the distance between the center of the first outer cylindrical member and the center of the third outer cylindrical member. [3] The balloon catheter according to [2], wherein, in the longitudinal direction, the length of the proximal region is equal to or less than the length of the distal region. [4] The balloon catheter according to [2] or [3], wherein the inner cylindrical member has an opening in the proximal region between adjacent outer cylindrical members in the circumferential direction of the inner cylindrical member, through which the lumen of the inner cylindrical member communicates with the outside of the inner cylindrical member. [5] The balloon catheter according to [4], wherein the opening is located between the first outer cylindrical member and the second outer cylindrical member in the circumferential direction of the inner cylindrical member.[6] The balloon catheter according to any one of [2] to [5], wherein in a cross section perpendicular to the longitudinal direction in the proximal region, the distance between the outer surface of the first outer cylindrical member and the outer surface of the second outer cylindrical member is greater than the outer diameter of the outer cylindrical members constituting the cylindrical-member group. [7] The balloon catheter according to any one of [2] to [6], wherein in the proximal region, the cylindrical-member group includes at least one pair of outer cylindrical members in which adjacent outer cylindrical members are in contact with each other circumferentially around the inner cylindrical member constituting the cylindrical-member group, and at least one pair of outer cylindrical members in which adjacent outer cylindrical members are not in contact with each other circumferentially around the inner cylindrical member constituting the cylindrical-member group. [8] The balloon catheter according to [7], wherein in the distal region, the outer cylindrical members in the cylindrical-member group are in contact with each other circumferentially around the inner cylindrical member. [9] The balloon catheter according to any one of [2] to [8], wherein, in a cross section perpendicular to the longitudinal direction in the distal region, the distance between the outer surfaces of adjacent outer cylindrical members in the circumferential direction of the inner cylindrical member constituting the cylindrical member group is smaller than the outer diameter of the outer cylindrical member.

[10] The balloon catheter according to any one of [2] to [9], wherein, in a cross section perpendicular to the longitudinal direction in the distal region, the distance between the center of the first outer cylindrical member and the center of the second outer cylindrical member is 90% to 110% of the distance between the center of the first outer cylindrical member and the center of the third outer cylindrical member.

[11] The balloon catheter according to any one of [1] to

[10] , wherein the cylindrical member group includes an outer cylindrical member whose extension direction is inclined with respect to the extension direction of the inner cylindrical member.

[12] The balloon catheter according to [4], wherein, proximal to the opening, the outer cylindrical members constituting the cylindrical member group are arranged around the inner cylindrical member in the circumferential direction.

[13] The balloon catheter according to

[12] , further comprising an outer cylindrical member fixing region in which the outer cylindrical members constituting the cylindrical member group are fixed to each other, and the opening is disposed in the outer cylindrical member fixing region.

[14] The balloon catheter according to [4], further comprising a covering tube, and a component fixing region where the covering tube and the outer cylindrical member constituting the cylindrical member group are fixed to each other, and the opening is located in the component fixing region.

[15] The balloon catheter according to

[14] , wherein the covering tube is disposed distally from the component fixing region, the inner cylindrical member and the cylindrical member group are disposed in the lumen of the covering tube, and the covering tube is disposed proximal to the component fixing region, and the inner cylindrical member and the cylindrical member group are not present.

[16] The balloon catheter according to

[14] , wherein the inner cylindrical member and the cylindrical member group are disposed in the lumen of the covering tube distally from the component fixing region, and the cylindrical member group is disposed proximal to the component fixing region, and the inner cylindrical member is not present.

[17] The balloon catheter according to any one of [1] to

[16] , wherein the inner cavity of the inner cylindrical member is a guidewire lumen through which a guidewire is inserted, and the inner cavity of the outer cylindrical member constituting the cylindrical member group is an inflation lumen through which fluid supplied to the lumen of the balloon passes, and is in communication with the lumens of each of the plurality of balloons.

[18] The balloon catheter according to

[17] , further comprising a guidewire tube having an inner cavity in communication with the guidewire lumen, the guidewire tube being disposed in the lumen of the balloon.

[19] The balloon catheter according to any one of [1] to

[18] , which is used to dilate an aortic valve, deform a biological valve placed in the heart, or destroy the biological valve.

[0010] In the balloon catheter described above, in a cross section perpendicular to the longitudinal direction, the shaft has a portion in which the distance between the center of the first outer cylindrical member and the center of the second outer cylindrical member is greater than the distance between the center of the first outer cylindrical member and the center of the third outer cylindrical member, thereby providing adjacent portions in which the shaft has low rigidity due to a large gap between the first and second outer cylindrical members in the circumferential direction of the inner cylindrical member and high rigidity due to a small gap between the first and third outer cylindrical members in the circumferential direction of the inner cylindrical member. As a result, the shaft is structured to bend selectively between the first and second outer cylindrical members, improving the shaft's trackability and facilitating insertion into a biological lumen.

[0011] 1 shows a side view of a balloon catheter according to one embodiment of the present invention. 2 shows a side view of a balloon of the balloon catheter shown in FIG. 1. 3 shows a side view of a shaft at the proximal region of the balloon catheter shown in FIG. 1. 4 shows a cross-sectional view IV-IV of the shaft shown in FIG. 3. 5 shows a side view of a shaft at the distal region of the balloon catheter shown in FIG. 1. 6 shows a cross-sectional view VI-VI of the shaft shown in FIG. 5. 7 shows a side view of a shaft at the proximal region of a balloon catheter according to another embodiment of the present invention. 8 shows a side view of a shaft at the proximal region of a balloon catheter according to yet another embodiment of the present invention.

[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 implemented with appropriate modifications within the scope of the above and below-described purposes, and all such modifications are included within the technical scope of the present invention. In addition, hatching and component symbols may be omitted in each drawing for convenience. In such cases, please refer to the specification or other drawings. Furthermore, the dimensions of various components in the drawings may differ from the actual dimensions, as priority is given to helping understand the features of the present invention.

[0013] A balloon catheter according to an embodiment of the present invention comprises a shaft extending longitudinally from a proximal side to a distal side and a plurality of balloons disposed in a distal portion of the shaft. The shaft comprises an inner cylindrical member having an inner lumen and a cylindrical member group composed of a plurality of outer cylindrical members, each having an inner lumen, arranged in a line around the circumferential direction of the inner cylindrical member. In a cross section perpendicular to the longitudinal direction, the cylindrical member group includes a first outer cylindrical member, a second outer cylindrical member arranged adjacent to the first outer cylindrical member around the circumferential direction of the inner cylindrical member, and a third outer cylindrical member arranged adjacent to the first outer cylindrical member around the circumferential direction of the inner cylindrical member and on the opposite side of the second outer cylindrical member. In the cross section perpendicular to the longitudinal direction, the distance between the center of the first outer cylindrical member and the center of the second outer cylindrical member is greater than the distance between the center of the first outer cylindrical member and the center of the third outer cylindrical member.

[0014] Balloon catheters according to embodiments of the present invention will be described below with reference to Figures 1 to 6. 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 side view of the shaft in the proximal region of the balloon catheter shown in Figure 1. Figure 4 is a cross-sectional view of the shaft shown in Figure 3 taken along line IV-IV, which is a cross-sectional view perpendicular to the longitudinal direction of the shaft. Figure 5 is a side view of the shaft in the distal region of the balloon catheter shown in Figure 1. Figure 6 is a cross-sectional view of the shaft shown in Figure 5 taken along line VI-VI, which is 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 treatment subject, is referred to as the distal side.

[0017] Members and parts other than the shaft 10 also have longitudinal, radial, 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, radial, 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, an indeflator (a balloon pressurizer) can be used to introduce or discharge the fluid. The fluid may be, for example, saline or a mixture of a contrast agent and saline. The fluid may also be a pressurized fluid pressurized by a pump or the like.

[0019] Examples of materials that can be used to form 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. That is, it is preferable that each of the multiple balloons 20 is made of the same material. By using the same material constituting each of the multiple balloons 20, it is possible to make the degree of expansion and hardness of the balloons 20 approximately the same in the circumferential direction z1 of the balloons 20.

[0021] In the inflated state of the balloons 20, the maximum outer diameters of the multiple balloons 20 may be different, but are preferably the same. The same maximum outer diameter of the multiple balloons 20 means that the maximum outer diameters of the multiple balloons 20 are approximately the same, specifically, that the maximum outer diameter of one balloon 20 is 90% to 110% of the maximum outer diameters of all the other balloons 20. Having the same maximum outer diameter of the multiple balloons 20 in the inflated state of the balloons 20 makes it easier to synchronize the timing of inflation of all the balloons 20 and to control the inflation of the balloons 20. The inflated state of the balloons 20 refers to a state in which fluid is introduced into the lumen of all the balloons 20 and the balloons 20 are inflated.

[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 multiple, but is preferably one. That is, 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 in an inflated state. As a result, the first balloon 21 is more likely to suppress the inflation of the multiple second balloons 22, and the hardness of the balloon 20 is increased, making it easier to increase the inflation force.

[0024] The number of second balloons 22 is preferably three or more, more preferably four or more, and even more preferably five or more. By setting the lower limit of the number of second balloons 22 within the above range, the first balloon 21 and the second balloon 22 are less likely to shift position when the balloon 20 is inflated, thereby increasing the inflation force of the balloon 20. Furthermore, the number of 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 second balloons 22 within the above range, the outer diameter of the balloon 20 is less likely to become excessively large, thereby improving the minimally invasive nature of the balloon catheter 1.

[0025] When the multiple balloons 20 are in an inflated state, the lengths in the longitudinal direction x1 from the distal end 20d of each balloon 20 to the proximal end 20p of each balloon 20 may be the same or different. When the multiple balloons 20 include a first balloon 21 and multiple second balloons 22, the lengths L2 in the longitudinal direction x1 from the distal end 20d of each second balloon 22 to the proximal end 20p of each second balloon 22 may be different but are preferably the same. The lengths L2 in the longitudinal direction x1 from the distal end 20d to the proximal end 20p of each second balloon 22 being the same means that the lengths L2 in the longitudinal direction x1 of the multiple second balloons 22 are approximately the same. Specifically, this means that the length L2 in the longitudinal direction x1 of one second balloon 22 is 90% to 110% of the lengths L2 in the longitudinal direction x1 of all the other second balloons 22. Since the length L2 in the longitudinal direction x1 of each of the multiple second balloons 22 when the balloon 20 is in an expanded state 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 tapered section 202 located proximal to the straight tube section 203, a proximal sleeve section 201 located proximal to the proximal tapered section 202, a distal tapered section 204 located distal to the straight tube section 203, and a distal sleeve section 205 located distal to the distal tapered section 204.

[0027] The straight tube portion 203 is preferably substantially cylindrical, having approximately the same diameter in the longitudinal direction x1, but may have different diameters in the longitudinal direction x1. The proximal tapered portion 202 and the distal tapered portion 204 are preferably formed into a substantially conical or truncated conical shape, with diameters decreasing as they move away from the straight tube portion 203. Having the largest diameter in the straight tube portion 203 ensures that the straight tube portion 203 of the balloon 20 can adequately contact the lesion when the balloon 20 is inflated at a lesion such as a stenosis, facilitating treatment such as dilation of the lesion. Furthermore, because the proximal tapered portion 202 and the distal tapered portion 204 are tapered, the outer diameters of the proximal and distal ends of the balloon 20 can be reduced when the balloon 20 is deflated, thereby reducing the step between the shaft 10 and the balloon 20. Therefore, the outer surface of the balloon catheter 1 is smooth when the balloon 20 is deflated, facilitating insertion of the balloon catheter 1 into a body cavity.

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

[0029] The shaft 10 has an inner cylindrical member 130 having an inner lumen, and a cylindrical member group 400 made up of a plurality of outer cylindrical members 140 having inner lumens and arranged in a line around the circumference of the inner cylindrical member 130 outside the inner cylindrical member 130. In other words, the shaft 10 has the inner cylindrical member 130 and a plurality of outer cylindrical members 140.

[0030] The inner cylindrical member 130 is preferably made of resin, metal, or a combination of resin and metal. Using resin as the constituent material of the inner cylindrical member 130 makes it easier to impart flexibility and elasticity to the inner cylindrical member 130. Furthermore, using metal as the constituent material of the inner cylindrical member 130 can improve the deliverability of the balloon catheter 1. Examples of resins that can be used to form the inner cylindrical member 130 include polyamide-based resins, polyester-based resins, polyurethane-based resins, polyolefin-based resins, fluorine-based resins, vinyl chloride-based resins, silicone-based resins, natural rubber, and synthetic rubber. These may be used alone or in combination. Examples of metals that can be used to form the inner cylindrical member 130 include stainless steels such as SUS304 and SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, gold, Ni-Ti alloys, Co-Cr alloys, and combinations thereof. When the inner cylindrical member 130 is composed of a distal inner cylindrical member 135 and a proximal inner cylindrical member 136 that are separate members, the distal inner cylindrical member 135 may be made of resin, and the proximal inner cylindrical member 136 may be made of metal. The inner cylindrical member 130 may also have a laminated structure made of different materials or the same material.

[0031] The inner cylindrical member 130 has an inner lumen extending in the longitudinal direction x1. The inner cylindrical member 130 may have multiple lumen, but preferably has one lumen. Having one lumen in the inner cylindrical member 130 makes the inner cylindrical member 130 flexible, which makes it easier to increase the flexibility of the shaft 10.

[0032] The material constituting the outer cylindrical member 140 can be the same as the material constituting the inner cylindrical member 130. The material constituting the outer cylindrical member 140 may be the same as the material constituting the inner cylindrical member 130, or may be different.

[0033] The outer cylindrical member 140 has an inner lumen extending in the longitudinal direction x1. The outer cylindrical member 140 may have multiple inner lumen, but preferably has one lumen. Having one inner lumen in the outer cylindrical member 140 increases the flexibility of the outer cylindrical member 140, making it easier to provide a highly flexible shaft 10.

[0034] The materials constituting each of the multiple outer cylindrical members 140 constituting the cylindrical member group 400 may be different, but are preferably the same. In other words, the cylindrical member group 400 is preferably composed of multiple outer cylindrical members 140 made of the same material. By using the same material to constitute the multiple outer cylindrical members 140, it is possible to make the rigidity of the cylindrical member group 400 approximately the same in the circumferential direction z1 of the cylindrical member group 400.

[0035] The outer diameters of the multiple outer cylindrical members 140 constituting the cylindrical member group 400 may be different, but are preferably the same. The multiple outer cylindrical members 140 constituting the cylindrical member group 400 having the same outer diameter means that the multiple outer cylindrical members 140 constituting the cylindrical member group 400 have approximately the same outer diameter, specifically, that the outer diameter of one outer cylindrical member 140 is 90% to 110% of the outer diameters of all the other outer cylindrical members 140. By having the multiple outer cylindrical members 140 constituting the cylindrical member group 400 have the same outer diameter, all of the outer cylindrical members 140 constituting the cylindrical member group 400 have approximately the same rigidity, which makes it easier for the shaft 10 to have approximately the same flexibility in the circumferential direction z1 of the cylindrical member group 400.

[0036] The outer diameter of the inner cylindrical member 130 is preferably larger than the outer diameter of the outer cylindrical member 140. By making the outer diameter of the inner cylindrical member 130 larger than the outer diameter of the outer cylindrical member 140, it is easy to arrange the multiple outer cylindrical members 140 side by side outside the inner cylindrical member 130 in the circumferential direction z1, and also the multiple outer cylindrical members 140 are less likely to become misaligned.

[0037] The outer diameter of the inner cylindrical member 130 is preferably 1.5 times or more, more preferably 2.0 times or more, and even more preferably 2.5 times or more, the outer diameter of the outer cylindrical member 140. By setting the lower limit of the ratio of the outer diameter of the inner cylindrical member 130 to the outer diameter of the outer cylindrical member 140 within the above range, it becomes easier to arrange multiple outer cylindrical members 140 around the inner cylindrical member 130 in the circumferential direction z1. Furthermore, the outer diameter of the inner cylindrical member 130 is preferably 10 times or less, more preferably 8 times or less, and even more preferably 5 times or less, the outer diameter of the outer cylindrical member 140. By setting the upper limit of the ratio of the outer diameter of the inner cylindrical member 130 to the outer diameter of the outer cylindrical member 140 within the above range, the outer diameter of the shaft 10 is less likely to become large and the shaft 10 can be made more flexible.

[0038] The balloon 20 and the shaft 10 can be joined by bonding with an adhesive, welding, or by attaching a ring-shaped member to the overlapping portion of the end of the balloon 20 and the shaft 10 and crimping the end. 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 less likely to come loose even when the balloon 20 is repeatedly expanded or contracted, and the bond strength can be improved.

[0039] 1 , a hub 5 may be provided on the proximal side of the shaft 10. The hub 5 may also be provided with a fluid injection section 6 that communicates with a flow path for fluid supplied to the interior of the balloon 20.

[0040] The shaft 10 and the hub 5 can be joined by, for example, bonding with an adhesive or welding. Among these, it is preferable that the shaft 10 and the hub 5 are joined by adhesive. By joining the shaft 10 and the hub 5 by adhesive, 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.

[0041] 4 and 6 , in a cross section perpendicular to the longitudinal direction x1, the cylindrical member group 400 includes a first outer cylindrical member 410, a second outer cylindrical member 420 arranged adjacent to the first outer cylindrical member 410 in the circumferential direction z1 of the inner cylindrical member 130, and a third outer cylindrical member 430 arranged adjacent to the first outer cylindrical member 410 in the circumferential direction z1 of the inner cylindrical member 130 and on the opposite side of the second outer cylindrical member 420. In other words, the cylindrical member group 400 includes the first outer cylindrical member 410, the second outer cylindrical member 420 arranged on one side of the inner cylindrical member 130 in the circumferential direction z1 with respect to the first outer cylindrical member 410, and the third outer cylindrical member 430 arranged on the other side of the inner cylindrical member 130 in the circumferential direction z1 with respect to the first outer cylindrical member 410. In other words, the second outer cylindrical member 420, the first outer cylindrical member 410, and the third outer cylindrical member 430 are arranged in this order toward one side of the inner cylindrical member 130 in the circumferential direction z1.

[0042] The first outer cylindrical member 410 and the second outer cylindrical member 420 are adjacent to each other in the circumferential direction z1 of the inner cylindrical member 130. The first outer cylindrical member 410 and the second outer cylindrical member 420 may be in contact with each other, or there may be a gap between the first outer cylindrical member 410 and the second outer cylindrical member 420.

[0043] The first outer cylindrical member 410 and the third outer cylindrical member 430 are adjacent to each other in the circumferential direction z1 of the inner cylindrical member 130. The first outer cylindrical member 410 and the third outer cylindrical member 430 may be in contact with each other, or there may be a gap between the first outer cylindrical member 410 and the third outer cylindrical member 430.

[0044] 3 and 4 , in a cross section perpendicular to the longitudinal direction x1, the shaft 10 has a portion where the distance D10 between the center C410 of the first outer cylinder member 410 and the center C420 of the second outer cylinder member 420 is greater than the distance D11 between the center C410 of the first outer cylinder member 410 and the center C430 of the third outer cylinder member 430. The center C410 of the first outer cylinder member 410 in the cross section perpendicular to the longitudinal direction x1 refers to the centroid of the outer edge of the cross-sectional shape of the first outer cylinder member 410. Similarly, the center C420 of the second outer cylinder member 420 in the cross section perpendicular to the longitudinal direction x1 refers to the centroid of the outer edge of the cross-sectional shape of the second outer cylinder member 420, and the center C430 of the third outer cylinder member 430 in the cross section perpendicular to the longitudinal direction x1 refers to the centroid of the outer edge of the cross-sectional shape of the third outer cylinder member 430.

[0045] In a cross section perpendicular to the longitudinal direction x1, the shaft 10 has a portion where the distance D10 between the center C410 of the first outer cylindrical member 410 and the center C420 of the second outer cylindrical member 420 is greater than the distance D11 between the center C410 of the first outer cylindrical member 410 and the center C430 of the third outer cylindrical member 430.Therefore, in at least a portion of the shaft 10, the distance between the first outer cylindrical member 410 and the second outer cylindrical member 420 in the circumferential direction z1 of the inner cylindrical member 130 can be made greater than the distance between the first outer cylindrical member 410 and the third outer cylindrical member 430 in the circumferential direction z1 of the inner cylindrical member 130. In a cross section perpendicular to the longitudinal direction x1, the shaft 10 has adjacent portions where the rigidity of the shaft 10 is low due to a large gap between the first outer cylindrical member 410 and the second outer cylindrical member 420 in the circumferential direction z1 of the inner cylindrical member 130, and portions where the rigidity of the shaft 10 is high due to a small gap between the first outer cylindrical member 410 and the third outer cylindrical member 430 in the circumferential direction z1 of the inner cylindrical member 130. As a result, the shaft 10 has a structure that allows it to bend selectively between the first outer cylindrical member 410 and the second outer cylindrical member 420. The selectively flexible structure of the shaft 10 makes it possible to improve the tracking ability of the shaft 10 in blood vessels with large curvatures, such as the aortic arch.

[0046] In a cross section perpendicular to the longitudinal direction x1, the distance D10 between the center C410 of the first outer cylindrical member 410 and the center C420 of the second outer cylindrical member 420 is preferably 1.5 times or more, more preferably 1.7 times or more, and even more preferably 2.0 times or more, of the distance D11 between the center C410 of the first outer cylindrical member 410 and the center C430 of the third outer cylindrical member 430. By setting the lower limit value of the ratio between the distance D10 between the center C410 of the first outer cylindrical member 410 and the center C420 of the second outer cylindrical member 420 and the distance D11 between the center C410 of the first outer cylindrical member 410 and the center C430 of the third outer cylindrical member 430 to the above range, it becomes easier to increase the gap between the first outer cylindrical member 410 and the second outer cylindrical member 420 in the circumferential direction z1 of the inner cylindrical member 130, and the rigidity between the first outer cylindrical member 410 and the second outer cylindrical member 420 of the shaft 10 can be reduced. Furthermore, in a cross section perpendicular to the longitudinal direction x1, the distance D10 between the center C410 of the first outer cylindrical member 410 and the center C420 of the second outer cylindrical member 420 is preferably 10 times or less, more preferably 7 times or less, and even more preferably 5 times or less, the distance D11 between the center C410 of the first outer cylindrical member 410 and the center C430 of the third outer cylindrical member 430. By setting the upper limit of the ratio of the distance D10 between the center C410 of the first outer cylindrical member 410 and the center C420 of the second outer cylindrical member 420 to the distance D11 between the center C410 of the first outer cylindrical member 410 and the center C430 of the third outer cylindrical member 430 within the above range, the distance between the first outer cylindrical member 410 and the second outer cylindrical member 420 in the circumferential direction z1 of the inner cylindrical member 130 is maintained, while also providing a portion with a small gap and high rigidity between the first outer cylindrical member 410 and the third outer cylindrical member 430 in the circumferential direction z1 of the inner cylindrical member 130. This makes it easier to achieve a structure in which the shaft 10 can bend selectively between the first outer cylindrical member 410 and the second outer cylindrical member 420.

[0047] As shown in Figures 1, 3 and 5, the shaft 10 preferably has a distal region A3, which is a region on the distal side, and a proximal region A4, which is a region located proximal to the distal region A3.

[0048] The distal region A3 includes the distal end of the inner cylindrical member 130, and is preferably at least 1 / 30 of the length in the longitudinal direction x1 from the distal end of the inner cylindrical member 130 to the proximal end of the inner cylindrical member 130, a region extending from the distal end of the inner cylindrical member 130 toward the proximal side; more preferably at least 1 / 20 of the length in the longitudinal direction x1 from the distal end of the inner cylindrical member 130 to the proximal end of the inner cylindrical member 130, a region extending from the distal end of the inner cylindrical member 130 toward the proximal side; and even more preferably at least 1 / 10 of the length in the longitudinal direction x1 from the distal end of the inner cylindrical member 130 to the proximal end of the inner cylindrical member 130, a region extending from the distal end of the inner cylindrical member 130 toward the proximal side.

[0049] The proximal region A4 is located more proximal than the distal region A3, and is preferably an area that is 1 / 50 or more of the length in the longitudinal direction x1 from the distal end of the inner cylindrical member 130 to the proximal end of the inner cylindrical member 130, more preferably an area that is 1 / 30 or more of the length in the longitudinal direction x1 from the distal end of the inner cylindrical member 130 to the proximal end of the inner cylindrical member 130, and even more preferably an area that is 1 / 20 or more of the length in the longitudinal direction x1 from the distal end of the inner cylindrical member 130 to the proximal end of the inner cylindrical member 130.

[0050] When the inner cylindrical member 130 has a distal inner cylindrical member 135 and a proximal inner cylindrical member 136, the distal region A3 preferably includes the distal end 135d of the distal inner cylindrical member 135, and is 1 / 30 or more of the length in the longitudinal direction x1 from the distal end 135d of the distal inner cylindrical member 135 to the proximal end of the distal inner cylindrical member 135, and is a region extending from the distal end 135d of the distal inner cylindrical member 135 toward the proximal side. It is more preferable that the length be at least 1 / 20 of the length in the longitudinal direction x1 from the distal end 135d to the proximal end of the distal inner cylindrical member 135, or the region extending from the distal end 135d of the distal inner cylindrical member 135 toward the proximal side, and it is even more preferable that the length be at least 1 / 10 of the length in the longitudinal direction x1 from the distal end 135d of the distal inner cylindrical member 135 to the proximal end of the distal inner cylindrical member 135, or the region extending from the distal end 135d of the distal inner cylindrical member 135 toward the proximal side. The proximal region A4 is located more proximal than the distal region A3, includes the proximal end of the distal inner cylindrical member 135, and is preferably 1 / 50 or more of the length in the longitudinal direction x1 from the distal end 135d of the distal inner cylindrical member 135 to the proximal end of the distal inner cylindrical member 135, and is preferably a region extending from the proximal end of the distal inner cylindrical member 135 toward the distal side. It is more preferable that the length be at least 1 / 30 of the length in the longitudinal direction x1 to the proximal end of the rectangular cylindrical member 135, or the region extending from the proximal end of the distal inner rectangular cylindrical member 135 toward the distal side, and it is even more preferable that the length be at least 1 / 20 of the length in the longitudinal direction x1 from the distal end 135d of the distal inner rectangular cylindrical member 135 to the proximal end of the distal inner inner rectangular cylindrical member 135, or the region extending from the proximal end of the distal inner inner rectangular cylindrical member 135 toward the distal side.

[0051] As shown in Figure 4, in a cross section perpendicular to the longitudinal direction x1 in the proximal region A4, it is preferable that the distance D10 between the center C410 of the first outer cylindrical member 410 and the center C420 of the second outer cylindrical member 420 is greater than the distance D11 between the center C410 of the first outer cylindrical member 410 and the center C430 of the third outer cylindrical member 430.

[0052] In a cross section perpendicular to the longitudinal direction x1 in the proximal region A4, the distance D10 between the center C410 of the first outer cylindrical member 410 and the center C420 of the second outer cylindrical member 420 is greater than the distance D11 between the center C410 of the first outer cylindrical member 410 and the center C430 of the third outer cylindrical member 430, so that the distance between the first outer cylindrical member 410 and the second outer cylindrical member 420 in the circumferential direction z1 of the inner cylindrical member 130 can be greater than the distance between the first outer cylindrical member 410 and the third outer cylindrical member 430 in the circumferential direction z1 of the inner cylindrical member 130. In a cross section perpendicular to the longitudinal direction x1 in the proximal region A4 located a certain distance from the tip of the shaft 10, a portion where the rigidity of the shaft 10 is low due to a large gap between the first outer cylindrical member 410 and the second outer cylindrical member 420 in the circumferential direction z1 of the inner cylindrical member 130 and a portion where the rigidity of the shaft 10 is high due to a small gap between the first outer cylindrical member 410 and the third outer cylindrical member 430 in the circumferential direction z1 of the inner cylindrical member 130 are adjacent to each other. As a result, the shaft 10 has a structure that allows it to bend selectively between the first outer cylindrical member 410 and the second outer cylindrical member 420. The selectively flexible structure of the shaft 10 allows it to improve its tracking ability in blood vessels with large curvatures, such as the aortic arch.

[0053] In the longitudinal direction x1, the length of the proximal region A4 is preferably equal to or shorter than the length of the distal region A3. By making the length of the proximal region A4 the same as or shorter than the length of the distal region A3, the length of the highly flexible proximal region A4 and the length of the distal region A3, which have appropriate rigidity, are balanced throughout the shaft 10, resulting in a shaft 10 with good insertability. Furthermore, in the longitudinal direction x1, the length of the proximal region A4 is more preferably shorter than the length of the distal region A3. By making the length of the proximal region A4 shorter than the length of the distal region A3, the insertability of the shaft 10 can be further improved.

[0054] 1 and 3 , the inner cylindrical member 130 preferably has an opening 131 in the proximal region A4 between adjacent outer cylindrical members 140 in the circumferential direction z1 of the inner cylindrical member 130, which connects the inner cavity of the inner cylindrical member 130 to the outside of the inner cylindrical member 130. By having the opening 131 between adjacent outer cylindrical members 140 in the proximal region A4, the balloon catheter 1 becomes a so-called rapid exchange type, making it easy to introduce items such as a guidewire or fluids into the inner cavity of the inner cylindrical member 130 through the opening 131. As a result, the procedure time using the balloon catheter 1 can be shortened, and minimal invasiveness can be improved.

[0055] The opening 131 is preferably located between the first outer cylindrical member 410 and the second outer cylindrical member 420 in the circumferential direction z1 of the inner cylindrical member 130. By having the opening 131 located between the first outer cylindrical member 410 and the second outer cylindrical member 420, the opening 131 is located between the first outer cylindrical member 410 and the second outer cylindrical member 420, which are spaced apart in the circumferential direction z1 of the inner cylindrical member 130. Therefore, when an article such as a guidewire is inserted through the opening 131, the article inserted through the opening 131 is less likely to come into contact with the outer cylindrical member 140, making it less likely to damage the outer cylindrical member 140.

[0056] 4 , in a cross section perpendicular to the longitudinal direction x1 in the proximal region A4, a distance D12 between the outer surface of the first outer cylindrical member 410 and the outer surface of the second outer cylindrical member 420 is preferably greater than the outer diameter of the outer cylindrical members 140 constituting the cylindrical member group 400. The distance D12 between the outer surface of the first outer cylindrical member 410 and the outer surface of the second outer cylindrical member 420 refers to the length of the shortest line connecting a point on the outer edge of the first outer cylindrical member 410 and a point on the outer edge of the second outer cylindrical member 420. In other words, in a cross section perpendicular to the longitudinal direction x1 in the proximal region A4, the distance between the first outer cylindrical member 410 and the second outer cylindrical member 420 is preferably greater than the outer diameter of the outer cylindrical member 140. Since the distance D12 between the outer surface of the first outer cylindrical member 410 and the outer surface of the second outer cylindrical member 420 is larger than the outer diameter of the outer cylindrical members 140 that make up the cylindrical member group 400, the spacing between the first outer cylindrical member 410 and the second outer cylindrical member 420 can be made wider, thereby increasing the rigidity of the shaft 10 in the proximal region A4 and improving insertion ease.

[0057] In a cross section perpendicular to the longitudinal direction x1 in the proximal region A4, the distance D12 between the outer surface of the first outer cylindrical member 410 and the outer surface of the second outer cylindrical member 420 is preferably 2.0 times or more, more preferably 2.5 times or more, and even more preferably 3.0 times or more the outer diameter of the outer cylindrical member 140 constituting the cylindrical member group 400. By setting the lower limit of the ratio of the distance D12 between the outer surface of the first outer cylindrical member 410 and the outer surface of the second outer cylindrical member 420 to the outer diameter of the outer cylindrical member 140 constituting the cylindrical member group 400 within the above range, a sufficient gap can be secured between the first outer cylindrical member 410 and the second outer cylindrical member 420, making it easier to increase the rigidity of the shaft 10 in the proximal region A4. Furthermore, in a cross section perpendicular to the longitudinal direction x1 in the proximal region A4, the distance D12 between the outer surface of the first outer cylindrical member 410 and the outer surface of the second outer cylindrical member 420 is preferably 10 times or less, more preferably 7 times or less, and even more preferably 5 times or less the outer diameter of the outer cylindrical member 140 constituting the cylindrical member group 400. By setting the upper limit of the ratio of the distance D12 between the outer surface of the first outer cylindrical member 410 and the outer surface of the second outer cylindrical member 420 to the outer diameter of the outer cylindrical member 140 constituting the cylindrical member group 400 within the above range, the outer diameter of the shaft 10 is less likely to become excessively large, making the shaft 10 more minimally invasive.

[0058] 4 , in the proximal region A4, the tubular member group 400 preferably includes at least one set of outer cylindrical members 140 in which adjacent outer cylindrical members 140 are in contact with each other in the circumferential direction z1 of the inner cylindrical member 130 constituting the tubular member group 400, and at least one set of outer cylindrical members 140 in which adjacent outer cylindrical members 140 are not in contact with each other in the circumferential direction z1 of the inner cylindrical member 130 constituting the tubular member group 400. In other words, in the proximal region A4, the tubular member group 400 preferably includes both outer cylindrical members 140 in contact with adjacent outer cylindrical members 140 in the circumferential direction z1 of the inner cylindrical member 130, and outer cylindrical members 140 that are not in contact with adjacent outer cylindrical members 140 in the circumferential direction z1 of the inner cylindrical member 130. In the proximal region A4, the tubular member group 400 includes at least one set of outer cylindrical members 140 in which adjacent outer cylindrical members 140 are in contact with each other in the circumferential direction z1 of the inner cylindrical members 130 that make up the tubular member group 400, and at least one set of outer cylindrical members 140 in which adjacent outer cylindrical members 140 are not in contact with each other in the circumferential direction z1 of the inner cylindrical members 130 that make up the tubular member group 400.This increases the rigidity of the shaft 10 in the proximal region A4, making it easier for forces applied from the proximal side to be transmitted to the distal side, while also imparting a certain degree of flexibility to the shaft 10.

[0059] 5 and 6 , in the distal region A3, it is preferable that the outer cylindrical members 140 constituting the cylindrical member group 400 are not in contact with each other adjacent outer cylindrical members 140 in the circumferential direction z1 of the inner cylindrical member 130. By not having adjacent outer cylindrical members 140 in the distal region A3 in contact with each other, the flexibility of the shaft 10 in the distal region A3 can be increased, and the shaft 10 can be made to easily conform to an internal lumen such as a blood vessel.

[0060] 6 , in a cross section perpendicular to the longitudinal direction x1 in the distal region A3, the distance D13 between the outer surfaces of adjacent outer cylindrical members 140 in the circumferential direction z1 of the inner cylindrical member 130 constituting the cylindrical member group 400 is preferably smaller than the outer diameter of the outer cylindrical member 140. The distance D13 between the outer surfaces of the outer cylindrical members 140 refers to the length of the shortest line connecting a point on the outer edge of one outer cylindrical member 140 and a point on the outer edge of the other outer cylindrical member 140 adjacent to each other in the circumferential direction z1 of the inner cylindrical member 130. In other words, in a cross section perpendicular to the longitudinal direction x1 in the distal region A3, the distance between adjacent outer cylindrical members 140 is preferably larger than the outer diameter of the outer cylindrical members 140. Since the distance D13 between the outer surfaces of adjacent outer cylindrical members 140 is smaller than the outer diameter of the outer cylindrical members 140, it is possible to impart appropriate rigidity to the shaft 10 in the distal region A3, thereby improving pushability and making it possible to create a shaft 10 with good insertability.

[0061] In a cross section perpendicular to the longitudinal direction x1 in the distal region A3, the distance D13 between the outer surfaces of adjacent outer cylindrical members 140 in the circumferential direction z1 of the inner cylindrical member 130 constituting the cylindrical member group 400 is preferably 80% or less, more preferably 70% or less, and even more preferably 60% or less of the outer diameter of the outer cylindrical member 140. By setting the upper limit of the ratio of the distance D13 between the outer surfaces of adjacent outer cylindrical members 140 to the outer diameter of the outer cylindrical member 140 within the above range, the spacing between adjacent outer cylindrical members 140 can be narrowed, and the rigidity of the shaft 10 in the distal region A3 can be appropriately increased. Furthermore, in a cross section perpendicular to the longitudinal direction x1 in the distal region A3, the distance D13 between the outer surfaces of adjacent outer cylindrical members 140 in the circumferential direction z1 of the inner cylindrical member 130 constituting the cylindrical member group 400 is preferably 10% or more, more preferably 15% or more, and even more preferably 20% or more of the outer diameter of the outer cylindrical member 140. By setting the lower limit of the ratio of the distance D13 between the outer surfaces of adjacent outer cylindrical members 140 to the outer diameter of the outer cylindrical member 140 within the above range, the flexibility of the shaft 10 in the distal region A3 can be improved, and the shaft 10 can have good flexibility.

[0062] 6 , in a cross section perpendicular to the longitudinal direction x1 in the distal region A3, the distance D10 between the center C410 of the first outer cylinder member 410 and the center C420 of the second outer cylinder member 420 is preferably 90% to 110% of the distance D11 between the center C410 of the first outer cylinder member 410 and the center C430 of the third outer cylinder member 430. By setting the ratio of the distance D10 between the center C410 of the first outer cylinder member 410 and the center C420 of the second outer cylinder member 420 to the distance D11 between the center C410 of the first outer cylinder member 410 and the center C430 of the third outer cylinder member 430 within the above range in the cross section perpendicular to the longitudinal direction x1 in the distal region A3, the spacing between the multiple outer cylinder members 140 in the distal region A3 becomes approximately the same. That is, in the proximal region A4, the multiple outer cylindrical members 140 are arranged unevenly in the circumferential direction z1 of the inner cylindrical member 130, whereas in the distal region A3, the multiple outer cylindrical members 140 are arranged relatively evenly in the circumferential direction z1 of the inner cylindrical member 130. As a result, force applied from the proximal side of the shaft 10 is easily transmitted evenly, improving the insertability of the shaft 10.

[0063] In a cross section perpendicular to the longitudinal direction x1 in the distal region A3, the distance D10 between the center C410 of the first outer cylindrical member 410 and the center C420 of the second outer cylindrical member 420 is preferably 90% or more of the distance D11 between the center C410 of the first outer cylindrical member 410 and the center C430 of the third outer cylindrical member 430, more preferably 92% or more, even more preferably 95% or more, and preferably 110% or less, more preferably 108% or less, and even more preferably 105% or less. In a cross section perpendicular to the longitudinal direction x1 in the distal region A3, by setting the ratio of the distance D10 between the center C410 of the first outer cylindrical member 410 and the center C420 of the second outer cylindrical member 420 to the distance D11 between the center C410 of the first outer cylindrical member 410 and the center C430 of the third outer cylindrical member 430 within the above range, the spacing between the multiple outer cylindrical members 140 in the distal region A3 tends to be approximately the same, thereby further improving the insertability of the shaft 10.

[0064] 3 , the cylindrical member group 400 preferably includes an outer cylindrical member 140 whose extending direction is inclined with respect to the extending direction of the inner cylindrical member 130. In other words, the cylindrical member group 400 preferably includes an outer cylindrical member 140 whose extending direction is inclined with respect to the extending direction of the inner cylindrical member 130. By including an outer cylindrical member 140 whose extending direction is inclined with respect to the extending direction of the inner cylindrical member 130 in the cylindrical member group 400, there is an outer cylindrical member 140 that extends in a direction different from the extending direction of the inner cylindrical member 130. As a result, the arrangement of the tubular member group 400 composed of multiple outer tubular members 140 in a cross section perpendicular to the longitudinal direction x1 varies depending on the longitudinal direction x1, making it possible to change the characteristics between the distal and proximal sides of the shaft 10, such that the flexibility of the shaft 10 is increased on the distal side of the shaft 10 and the rigidity of the shaft 10 is increased on the proximal side of the shaft 10.

[0065] On the proximal side of the opening 131, the outer cylindrical member 140 constituting the cylindrical member group 400 is preferably arranged around the inner cylindrical member 130 in the circumferential direction z1. By arranging the outer cylindrical member 140 around the inner cylindrical member 130 in the circumferential direction z1 on the proximal side of the opening 131, the portion of the shaft 10 proximal to the opening 131 is supported by the outer cylindrical member 140, increasing the rigidity of the proximal side of the shaft 10 and improving pushability.

[0066] More preferably, on the proximal side of the opening 131, the outer cylindrical member 140 constituting the cylindrical member group 400 is arranged so as to be wound helically in the circumferential direction z1 of the inner cylindrical member 130. By arranging the outer cylindrical member 140 on the proximal side of the opening 131 so as to be wound helically in the circumferential direction z1 of the inner cylindrical member 130, it is possible to impart flexibility to the portion of the shaft 10 proximal to the opening 131, making it easier to bend, and improving pushability.

[0067] 3, the balloon catheter 1 has an outer cylindrical member fixing region A5, which is a region where the outer cylindrical members 140 constituting the cylindrical member group 400 are fixed to one another, and the opening 131 is preferably located in the outer cylindrical member fixing region A5. By locating the opening 131 in the outer cylindrical member fixing region A5, the rigidity of the portion of the inner cylindrical member 130 where the opening 131 is located can be increased, and the rigidity of the proximal side of the shaft 10 can be increased, thereby improving insertability.

[0068] FIG. 7 is a side view of the shaft in the proximal region of a balloon catheter according to another embodiment of the present invention, and FIG. 8 is a side view of the shaft in the proximal region of a balloon catheter according to yet another embodiment of the present invention.

[0069] 7 and 8 , the balloon catheter 1 further includes a covering tube 80 and a member fixing region A6 where the covering tube 80 and the outer cylindrical members 140 constituting the cylindrical member group 400 are fixed to each other, and the opening 131 is preferably located in the member fixing region A6. Fixing the covering tube 80 and the outer cylindrical members 140 constituting the cylindrical member group 400 to each other in the member fixing region A6 facilitates fixing of the multiple outer cylindrical members 140 by the covering tube 80, making it less likely for misalignment to occur. Furthermore, locating the opening 131 in the member fixing region A6 increases the rigidity of the portion where the opening 131 is located, resulting in a shaft 10 with good insertability.

[0070] Examples of materials that can be used to form the covering tube 80 include polyamide resins, polyester resins, polyurethane resins, polyolefin resins, fluorine-based resins, vinyl chloride resins, silicone resins, natural rubber, and synthetic rubber. These materials can be used alone or in combination. Among these, it is preferable that the material that forms the covering tube 80 contains the same resin as the resin that forms the shaft 10. By using a material that forms the covering tube 80 that contains the same resin as the resin that forms the shaft 10, the bonding strength between the covering tube 80 and the shaft 10 can be easily increased.

[0071] The covering tube 80 and the shaft 10 can be joined by, for example, adhesion with an adhesive, welding, etc. Among these, it is preferable that the covering tube 80 and the shaft 10 are joined by welding. By joining the covering tube 80 and the shaft 10 by welding, the joining between the covering tube 80 and the shaft 10 becomes difficult to be released, and it is possible to improve the joining strength.

[0072] 7 , it is preferable that the covering tube 80 is disposed distally of the component fixing region A6, the inner cylindrical member 130 and the cylindrical member group 400 are disposed in the lumen of the covering tube 80, and the covering tube 80 is disposed proximal to the component fixing region A6, without the inner cylindrical member 130 or the cylindrical member group 400. By disposing the inner cylindrical member 130 and the cylindrical member group 400 in the lumen of the covering tube 80 distally of the component fixing region A6 and not having the inner cylindrical member 130 or the cylindrical member group 400 proximal to the component fixing region A6, the outer diameter of the shaft 10 can be reduced in the portion proximal to the component fixing region A6, allowing for a shaft 10 with good passability.

[0073] 8, it is also preferable that the inner cylindrical member 130 and the cylindrical member group 400 are disposed in the lumen of the covering tube 80 distal to the member fixing region A6, and that the cylindrical member group 400 is disposed in the lumen of the covering tube 80 proximal to the member fixing region A6, without the inner cylindrical member 130. Since the cylindrical member group 400 is disposed in the lumen of the covering tube 80 proximal to the member fixing region A6 and the inner cylindrical member 130 is not present, the cylindrical member group 400 is present in the lumen of the covering tube 80 proximal to the member fixing region A6, and the rigidity is increased in the portion proximal to the member fixing region A6, making it possible to provide a shaft 10 with good insertability.

[0074] 3 and 5 , the inner cavity of the inner cylindrical member 130 is the guidewire lumen 13 through which a guidewire is inserted, and the inner cavity of the outer cylindrical member 140 constituting the cylindrical member group 400 is an inflation lumen through which fluid supplied to the lumen of the balloon 20 passes, and it is preferable that these lumen communicate with the lumens of the multiple balloons 20. Since the inner cavity of the inner cylindrical member 130 is the guidewire lumen 13 and the inner cavity of the outer cylindrical member 140 is an inflation lumen, it is easy to insert a guidewire into the inner cylindrical member 130 having the guidewire lumen 13, and it is also possible to make the outer cylindrical member 140 less likely to be damaged when a guidewire is inserted into the inner cylindrical member 130.

[0075] 1 and 2, the balloon catheter 1 preferably further includes a guidewire tube 40 having an inner cavity communicating with the guidewire lumen 13, the guidewire tube 40 being disposed within the inner cavity of the balloon 20. By including the guidewire tube 40 having an inner cavity communicating with the guidewire lumen 13, the balloon catheter 1 can be easily inserted with a guidewire, allowing the balloon catheter 1 to be delivered into the body along the guidewire. Furthermore, by inserting the guidewire through the guidewire tube 40, it is possible to prevent the guidewire from damaging the balloon 20, etc.

[0076] 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, fluorine-containing resins such as PTFE, PFA, and ETFE, and synthetic resins such as polyvinyl chloride resins. Among these, polyimide resins are preferred as the material constituting the guidewire tube 40. Using polyimide resin as the material constituting the guidewire tube 40 improves the lubricity of the guidewire tube 40. This facilitates inserting a guidewire through the lumen of the guidewire tube 40 and feeding the balloon catheter 1 into the body along the guidewire. The guidewire tube 40 may also have a multilayer structure including a braided layer such as a metal braid. The multilayer structure of the guidewire tube 40 can improve the strength of the guidewire tube 40, its lubricity relative to the guidewire, and its kink resistance.

[0077] The opening 131 is preferably a guidewire port 50 for inserting a guidewire into the lumen of the inner cylindrical member 130. That is, the balloon catheter 1 of the present invention is preferably a so-called rapid exchange type balloon catheter 1. The balloon catheter 1 preferably has a distal shaft 15 and a proximal shaft 16. 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 a shaft 10 extending from the balloon 20 to the proximal end of the balloon catheter 1. Alternatively, a single 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 formed from multiple tubular members.

[0078] 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. Connecting the proximal end of the guidewire tube 40 to the distal end of the shaft 10 prevents the outer diameter of the balloon catheter 1 from becoming large, thereby improving minimal invasiveness.

[0079] A tip member 60 is preferably provided at the distal end of the balloon catheter 1. The tip member 60 may be provided at the distal end of the balloon catheter 1 as a separate member from the guidewire tube 40 and connected to the distal end of the balloon 20, or the guidewire tube 40 extending distally beyond the distal end 20d of the balloon 20 may function as the tip member 60.

[0080] As shown in Figures 1 and 2, a radiopaque marker 70 may be placed on the guidewire tube 40 inside the balloon 20 at the location where the balloon 20 is located in the longitudinal axis direction x1 so that the position of the balloon 20 can be confirmed under X-ray fluoroscopy.

[0081] Examples of positions on the guidewire tube 40 where the radiopaque marker 70 is disposed include the midpoint of the length from the distal end 20d of the balloon 20 to the proximal end 20p of the balloon 20, and the proximal end 203p and distal end 203d of the straight tube portion 203 of the balloon 20. In particular, the positions on the guidewire tube 40 where the radiopaque marker 70 is disposed are preferably the proximal end 203p and distal end 203d of the straight tube portion 203 of the balloon 20. By disposing the radiopaque marker 70 on the guidewire tube 40 at the proximal end 203p and distal end 203d of the straight tube portion 203 of the balloon 20, the position of the balloon 20 can be easily confirmed. As a result, the balloon catheter 1 can be configured to easily apply pressure to a target location.

[0082] It is preferable that the shaft 10 has a coating applied to the outer wall of at least one of the distal shaft 15 and the proximal shaft 16, and it is more preferable that the outer wall of both the distal shaft 15 and the proximal shaft 16 have a coating applied.

[0083] 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, covering the outer wall of the shaft 10 with a hydrophilic or hydrophobic coating agent, etc. The coating agent may contain drugs, additives, etc.

[0084] Examples of hydrophilic coating agents include hydrophilic polymers such as polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyvinylpyrrolidone, methyl vinyl ether maleic anhydride copolymer, and the like, or hydrophilic coating agents made from any combination thereof.

[0085] 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 terminated with alkyl groups or perfluoroalkyl groups and having low surface free energy.

[0086] The balloon catheter 1 of the present invention is preferably used for dilating 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 dilating an aortic valve hardened by calcification or the like, or for deforming or destroying an artificial valve annulus 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 including multiple balloons 20, because the partitions between the multiple lumens in the shaft 10 are resistant to damage and fluids or objects introduced into one lumen are less likely to enter other lumens. This makes it suitable for use in dilating a hardened aortic valve and deforming or destroying a biological valve, which cannot be adequately dilated with conventional balloon catheters.

[0087] This application claims the benefit of priority based on Japanese Patent Application No. 2023-102818, filed on June 22, 2023. The entire contents of the specification of Japanese Patent Application No. 2023-102818, filed on June 22, 2023, are incorporated herein by reference.

[0088] 1: Balloon catheter 5: Hub 6: Fluid injection section 10: Shaft 13: Guidewire lumen 15: Distal shaft 16: Proximal shaft 20: Balloon 20d: Distal end of balloon 20p: Proximal end of balloon 201: Proximal sleeve section 201d: Distal end of proximal sleeve section 201p: Proximal end of proximal sleeve section 202: Proximal tapered section 202d: Distal end of proximal tapered section 202p: Proximal end of proximal tapered section 203: Straight tube section 203d: Distal end of straight tube section 203p: Proximal end of straight tube section 204: Distal tapered section 204d: Distal end of distal tapered section 204p: Proximal end of distal tapered section 205: Distal sleeve section 205d: Distal end of distal sleeve section 205p: Proximal end of distal sleeve portion 21: First balloon 22: Second balloon 40: Guidewire tube 50: Guidewire port 60: Distal tip member 70: Radiopaque marker 80: Covering tube 130: Inner cylindrical member 131: Opening 135: Distal inner cylindrical member 135d: Distal end of distal inner cylindrical member 136: Proximal inner cylindrical member 140: Outer cylindrical member 400: Group of cylindrical members 410: First outer cylindrical member 420: Second outer cylindrical member 430: Third outer cylindrical member A3: Distal region A4: Proximal region A5: Outer cylindrical member fixing region A6: Member fixing region C410: Center of first outer cylindrical member C420: Center of second outer cylindrical member C430: Center of the third outer cylindrical member D10: Distance between the center of the first outer cylindrical member and the center of the second outer cylindrical member D11: Distance between the center of the first outer cylindrical member and the center of the third outer cylindrical member D12: Distance between the outer surface of the first outer cylindrical member and the outer surface of the second outer cylindrical member D13: Distance between the outer surfaces of adjacent outer cylindrical members L2: Length from the distal end of the balloon to the proximal end of the balloon

Claims

1. A device comprising: a shaft extending longitudinally from a proximal side to a distal side; and a plurality of balloons disposed in a distal portion of the shaft; wherein the shaft comprises an inner cylindrical member having a lumen; and a cylindrical member group consisting of a plurality of outer cylindrical members, each having a lumen, disposed outside the inner cylindrical member and aligned in a circumferential direction of the inner cylindrical member; wherein, in a cross section perpendicular to the longitudinal direction, the cylindrical member group includes a first outer cylindrical member, a second outer cylindrical member disposed adjacent to the first outer cylindrical member in the circumferential direction of the inner cylindrical member, and a third outer cylindrical member disposed adjacent to the first outer cylindrical member in the circumferential direction of the inner cylindrical member and on the opposite side of the second outer cylindrical member; A balloon catheter, wherein in a cross section perpendicular to the longitudinal direction, the shaft has a portion in which the distance between the center of the first outer cylindrical member and the center of the second outer cylindrical member is greater than the distance between the center of the first outer cylindrical member and the center of the third outer cylindrical member.

2. A balloon catheter as described in claim 1, wherein the shaft has a distal region, which is a region on the distal side, and a proximal region, which is a region located proximal to the distal region, and in a cross section perpendicular to the longitudinal direction in the proximal region, the distance between the center of the first outer cylindrical member and the center of the second outer cylindrical member is greater than the distance between the center of the first outer cylindrical member and the center of the third outer cylindrical member.

3. The balloon catheter according to claim 2, wherein the length of the proximal region is equal to or less than the length of the distal region in the longitudinal direction.

4. A balloon catheter as described in claim 2, wherein the inner cylindrical member has an opening in the proximal region between adjacent outer cylindrical members in the circumferential direction of the inner cylindrical member, which connects the inner cavity of the inner cylindrical member to the outside of the inner cylindrical member.

5. A balloon catheter according to claim 4, wherein the opening is located between the first outer cylindrical member and the second outer cylindrical member in the circumferential direction of the inner cylindrical member.

6. A balloon catheter as described in claim 2, wherein in a cross section perpendicular to the longitudinal direction in the proximal region, the distance between the outer surface of the first outer cylindrical member and the outer surface of the second outer cylindrical member is greater than the outer diameter of the outer cylindrical members that make up the group of cylindrical members.

7. A balloon catheter as described in claim 2, wherein in the proximal region, the group of tubular members includes at least one set of outer cylindrical members in which adjacent outer cylindrical members are in contact with each other in the circumferential direction of the inner cylindrical member constituting the group of tubular members, and at least one set of outer cylindrical members in which adjacent outer cylindrical members are not in contact with each other in the circumferential direction of the inner cylindrical member constituting the group of tubular members.

8. A balloon catheter as described in claim 7, wherein in the distal region, the outer cylindrical members constituting the group of cylindrical members are such that adjacent outer cylindrical members in the circumferential direction of the inner cylindrical member are not in contact with each other.

9. A balloon catheter as described in claim 2, wherein in a cross section perpendicular to the longitudinal direction in the distal region, the distance between the outer surfaces of adjacent outer cylindrical members in the circumferential direction of the inner cylindrical member constituting the group of cylindrical members is smaller than the outer diameter of the outer cylindrical member.

10. A balloon catheter as described in claim 2, wherein in a cross section perpendicular to the longitudinal direction in the distal region, the distance between the center of the first outer cylindrical member and the center of the second outer cylindrical member is 90% or more and 110% or less of the distance between the center of the first outer cylindrical member and the center of the third outer cylindrical member.

11. The balloon catheter according to claim 1, wherein the group of cylindrical members includes the outer cylindrical member whose extending direction is inclined with respect to the extending direction of the inner cylindrical member.

12. A balloon catheter as described in claim 4, wherein the outer cylindrical member constituting the group of cylindrical members is arranged around the inner cylindrical member in the circumferential direction on the proximal side of the opening.

13. A balloon catheter as described in claim 12, which has an outer cylindrical member fixing region in which the outer cylindrical members constituting the cylindrical member group are fixed to each other, and the opening is disposed in the outer cylindrical member fixing region.

14. A balloon catheter as described in claim 4, further comprising a covering tube, a member fixing region in which the covering tube and the outer cylindrical member constituting the cylindrical member group are fixed to each other, and the opening is disposed in the member fixing region.

15. A balloon catheter as described in claim 14, wherein the covering tube is positioned distal to the member fixing region, the inner cylindrical member and the group of cylindrical members are positioned in the lumen of the covering tube, and the covering tube is positioned proximal to the member fixing region, and the inner cylindrical member and the group of cylindrical members are not present.

16. A balloon catheter as described in claim 14, wherein the inner cylindrical member and the group of cylindrical members are arranged in the lumen of the covering tube distal to the member fixing region, and the group of cylindrical members are arranged in the lumen of the covering tube proximal to the member fixing region, and the inner cylindrical member is not present.

17. A balloon catheter as described in claim 1, wherein the inner cavity of the inner cylindrical member is a guidewire lumen through which a guidewire is inserted, and the inner cavity of the outer cylindrical member constituting the cylindrical member group is an inflation lumen through which fluid supplied to the inner cavity of the balloon passes, and which is connected to the inner lumens of each of the plurality of balloons.

18. The balloon catheter according to claim 17, further comprising a guidewire tube having an inner cavity communicating with said guidewire lumen, said guidewire tube being disposed in the inner cavity of said balloon.

19. A balloon catheter according to any one of claims 1 to 18, which is used to dilate an aortic valve, deform a biological valve placed in the heart, or destroy said biological valve.

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