Balloon catheter

Abstract

This balloon catheter (100) has a group of balloon members, which includes a plurality of balloon members that are arranged, and a proximal shaft member (3) disposed proximally to the balloon members. The group of balloon members includes an inner balloon member and an outer balloon member. The proximal shaft member (3) has a guide wire lumen (30), a first lumen (31), and second lumens (32). In a cross section perpendicular to the longitudinal direction of the proximal shaft member (3), the distance between the centroid (30c) of the guide wire lumen (30) and the centroid (32c) of each second lumen (32) is larger than the distance between the centroid (30c) of the guide wire lumen (30) and the centroid (31c) of the first lumen (31).

Description

Balloon catheter

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

[0002] The formation of narrowed areas in blood vessel walls due to hardening caused by calcification and other factors 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 narrowed 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. Treatments for aortic stenosis include aortic valve replacement, which requires open chest surgery, and transcatheter aortic valve replacement, in which a biological valve (artificial valve) is placed via catheter to replace the hardened aortic valve.

[0004] Patent document 1 discloses a balloon catheter used for dilating hardened stenotic areas and placing biological valves, in which multiple outer balloon members are arranged to surround the outer surface of an inner balloon member.

[0005] US Patent Application Publication No. 2012 / 0209375

[0006] However, with the balloon catheter described in Patent Document 1, as the number of balloons increases, it becomes difficult to ensure the wall thickness of the portion of the shaft where the inflation lumen and the guidewire lumen are formed, which can result in fluid leaking from the inflation lumen into the guidewire lumen.

[0007] The present invention has been made in consideration of the above circumstances, and its object is to provide a balloon catheter that can easily prevent fluid from leaking into the guidewire lumen.

[0008] One embodiment of the balloon catheter of the present invention that solves the above problems is as follows: [1] A balloon catheter comprising: a balloon section group including a plurality of balloon sections arranged in parallel; and a proximal shaft section located proximal to the balloon sections, wherein the balloon section group includes an inner balloon section equipped with a guidewire tube into which a guidewire is inserted, and an outer balloon section located radially outward of the inner balloon section, wherein the proximal shaft section has a guidewire lumen through which the guidewire is inserted, a first lumen through which a fluid supplied to the inner balloon section can pass, and a second lumen through which a fluid supplied to the outer balloon section can pass, wherein in a cross section perpendicular to the longitudinal direction of the proximal shaft section, the distance between the centroid of the guidewire lumen and the centroid of the second lumen is longer than the distance between the centroid of the guidewire lumen and the centroid of the first lumen.

[0009] By making the distance between the centroid of the guidewire lumen and the centroid of the second lumen longer than the distance between the centroid of the guidewire lumen and the centroid of the first lumen, it is possible to prevent the portion between the second lumen and the guidewire lumen from becoming too thin due to the second lumen being too close to the guidewire lumen, thereby making it easier to prevent fluid from leaking from the second lumen into the guidewire lumen.

[0010] The balloon catheter according to an embodiment of the present invention is preferably any one of the following [2] to

[12] . [2] The balloon catheter according to [1], wherein, in a cross section perpendicular to the longitudinal direction of the proximal shaft, the first lumen is located on a line segment connecting the centroid of the guidewire lumen and the centroid of the second lumen. [3] The balloon catheter according to [1], wherein, in a cross section perpendicular to the longitudinal direction of the proximal shaft, the first lumen is not located on a line segment connecting the centroid of the guidewire lumen and the centroid of the second lumen. [4] The balloon catheter according to any one of [1] to [3], wherein, in a cross section perpendicular to the longitudinal direction of the proximal shaft, the centroid of the guidewire lumen is offset from the centroid of the proximal shaft. [5] The balloon catheter according to any one of [1] to [4], wherein, in a cross section perpendicular to the longitudinal direction of the proximal shaft, the outer shape of the first lumen is different from the outer shape of the second lumen. [6] The balloon catheter according to any one of [1] to [5], wherein the outer shape of the first lumen is irregular in a cross section perpendicular to the longitudinal direction of the proximal shaft. [7] The balloon catheter according to any one of [1] to [6], wherein the cross-sectional area of ​​the first lumen is larger than the cross-sectional area of ​​the second lumen in a cross section perpendicular to the longitudinal direction of the proximal shaft. [8] The balloon catheter according to any one of [1] to [6], wherein the cross-sectional area of ​​the second lumen is larger than the cross-sectional area of ​​the first lumen in a cross section perpendicular to the longitudinal direction of the proximal shaft. [9] The balloon catheter according to any one of [1] to [8], wherein the balloon catheter has a proximal sleeve section connecting the balloon section and the proximal shaft section, and the proximal sleeve section has a flow path through which a fluid can pass.

[10] The balloon catheter according to any one of [1] to [9], which has a distal shaft portion located distal to the balloon portion, and a distal sleeve portion connecting the balloon portion and the distal shaft portion.

[11] The balloon catheter according to

[10] , wherein the distal sleeve portion has a flow path through which a fluid can pass.

[12] The balloon catheter according to

[10] , wherein the distal sleeve portion does not have a flow path through which a fluid can pass.

[0011] The balloon catheter according to the embodiment of the present invention can easily prevent fluid from leaking from the second lumen into the guidewire lumen.

[0012] FIG. 1 is a side view of a balloon catheter according to an embodiment of the present invention. FIG. 2 is an enlarged side view of the balloon sections included in the balloon catheter shown in FIG. 1. FIG. 3 is a cross-sectional end view taken along line III-III in FIG. 2. FIG. 4 is a cross-sectional end view taken along line IV-IV in FIG. 2. FIG. 5 is a cross-sectional end view showing a modified version of the balloon catheter shown in FIG. 4. FIG. 6 is a cross-sectional end view showing a modified version of the balloon catheter shown in FIG. 4. FIG. 7 is a side view showing a modified version of the balloon sections included in FIG. 2. FIG. 8 is an enlarged cross-sectional view of the balloon section, distal sleeve section, and proximal sleeve section included in the balloon catheter shown in FIG. 1. FIG. 9 is a cross-sectional view showing a modified version of the balloon section, distal sleeve section, and proximal sleeve section shown in FIG. 8. FIG. 10 is a cross-sectional end view taken along line X-X in FIG. 2. FIG. 11 is a cross-sectional end view showing a modified version of the balloon catheter shown in FIG. 10. Figure 12 is a cross-sectional end view showing a modified example of the balloon catheter shown in Figure 10. Figure 13 is a cross-sectional end view showing a modified example of the balloon catheter shown in Figure 10.

[0013] The present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the illustrated examples, and appropriate modifications can be made within the scope of the above and below-described purpose, and all such modifications are within the technical scope of the present invention. In each drawing, hatching, symbols, etc. may be omitted for convenience. In such cases, reference should be made to the specification or other drawings. Furthermore, the dimensions of various parts in the drawings may differ from their actual dimensions, as priority is given to helping understand the features of the present invention.

[0014] One embodiment of the balloon catheter of the present invention has a balloon section group including a plurality of parallel balloon sections, and a proximal shaft section located proximal to the balloon sections. The balloon section group includes an inner balloon section equipped with a guidewire tube into which a guidewire is inserted, and an outer balloon section located radially outward of the inner balloon section. The proximal shaft section has a guidewire lumen through which the guidewire is inserted, a first lumen through which fluid supplied to the inner balloon section can pass, and a second lumen through which fluid supplied to the outer balloon section can pass. The gist of the balloon catheter is that in a cross section perpendicular to the longitudinal direction of the proximal shaft section, the distance between the centroid of the guidewire lumen and the centroid of the second lumen is longer than the distance between the centroid of the guidewire lumen and the centroid of the first lumen.

[0015] The overall configuration of a balloon catheter according to an embodiment of the present invention will be described with reference to Figures 1 to 13. These figures show a balloon catheter 100 comprising a balloon section group 1 and a proximal shaft section 3. In these figures, the longitudinal direction of the balloon catheter is indicated by x, the radial direction by y, and the circumferential direction by c.

[0016] Each of the members and parts of the balloon catheter 100 also has a longitudinal direction, a radial direction, and a circumferential direction. The longitudinal, radial, and circumferential directions of the members and parts of the balloon catheter 100 may or may not coincide with the longitudinal direction x, radial direction y, and circumferential direction c of the balloon catheter 100. For ease of understanding, this specification shows an embodiment in which the longitudinal, radial, and circumferential directions of all members and parts other than the distal sleeve section 4 and the proximal sleeve section 5 coincide with the longitudinal direction x, radial direction y, and circumferential direction c of the balloon catheter 100, respectively.

[0017] In this specification, the proximal side refers to the direction toward the user's hand relative to the longitudinal direction x of the balloon catheter 100, and the distal side refers to the opposite side of the proximal side, i.e., the direction toward the treatment target. Furthermore, when each component or part is divided into two equal parts in the longitudinal direction x of the balloon catheter 100, the distal part of each component or part is referred to as the distal portion of each component or part, and the proximal part of each component or part is referred to as the proximal portion of each component or part. The distal end of each component or part is the most distal end of each component or part. The proximal end of each component or part is the most proximal end of each component or part. The end includes the peripheral portion of the end. That is, the distal end refers to the distal end and the peripheral portion of the distal end, and the proximal end refers to the proximal end and the peripheral portion of the proximal end.

[0018] FIG. 1 is a side view of a balloon catheter according to an embodiment of the present invention. More specifically, FIG. 1 shows a state in which a balloon portion of the balloon catheter is inflated. FIG. 2 is an enlarged side view of the balloon portions of the balloon catheter shown in FIG. 1. FIG. 3 is a cross-sectional end view taken along line III-III in FIG. 2. FIG. 4 is a cross-sectional end view taken along line IV-IV in FIG. 2. FIGS. 5 and 6 are cross-sectional end views showing modified examples of the balloon catheter shown in FIG. 4. FIG. 7 is a side view showing modified examples of the balloon portions of the balloon catheter shown in FIG. 2. FIG. 8 is an enlarged cross-sectional view of the balloon portion, distal sleeve portion, and proximal sleeve portion of the balloon catheter shown in FIG. 1. FIG. 9 is a cross-sectional view showing modified examples of the balloon portion, distal sleeve portion, and proximal sleeve portion shown in FIG. 8. More specifically, FIGS. 8 and 9 are cross-sectional views taken along a plane passing through the central axis of the balloon portion and parallel to the longitudinal direction of the balloon catheter. Fig. 10 is a cross-sectional end view taken along line XX shown in Fig. 2. Figs. 11 to 13 are cross-sectional end views showing modified examples of the balloon catheter shown in Fig. 10.

[0019] As shown in FIGS. 1 and 2 , the balloon catheter 100 has a balloon section group 1 and a proximal shaft section 3 .

[0020] 1 to 3 and 7, the balloon section group 1 includes a plurality of parallel balloon sections 10. The plurality of balloon sections 10 are preferably aligned in a direction perpendicular to the longitudinal direction x of the balloon catheter 100.

[0021] The balloon portion 10 expands when fluid is supplied thereto and contracts when the fluid is discharged therefrom. FIG. 3 shows a cross-sectional end surface of the balloon portion 10 taken perpendicular to the longitudinal direction x of the balloon catheter 100. FIGS. 8 and 9 show cross sections of the balloon portion 10 taken parallel to the longitudinal direction x of the balloon catheter 100. To control the expansion and contraction of the balloon portion 10, an indeflator (balloon pressurizer) may be used to introduce or discharge fluid. Examples of fluids that can be used include gases such as nitrogen and air, and liquids such as saline and a mixture of a contrast agent and saline. The fluid may also be a pressurized fluid pressurized by a pump or the like.

[0022] 2, the balloon portion group 1 includes an inner balloon portion 11 equipped with a guidewire tube 13 into which a guidewire is inserted, and an outer balloon portion 12 located radially outward of the inner balloon portion 11. The inner balloon portion 11 refers to a balloon portion 10 among the multiple balloon portions 10 that has a guidewire tube 13 therein into which a guidewire is inserted. The outer balloon portion 12 refers to a balloon portion 10 among the multiple balloon portions 10 that does not have a guidewire tube 13 therein into which a guidewire is inserted, and that is located radially outward of the inner balloon portion 11.

[0023] As shown in FIG. 1 , the proximal shaft portion 3 is a portion located more proximal than the balloon portion 10 .

[0024] 4 to 6, the proximal shaft portion 3 has a guidewire lumen 30 through which a guidewire is inserted, a first lumen 31 through which fluid supplied to the inner balloon portion 11 can pass, and a second lumen 32 through which fluid supplied to the outer balloon portion 12 can pass. In a cross section perpendicular to the longitudinal direction x of the balloon catheter 100, the guidewire lumen 30, the first lumen 31, and the second lumen 32 are preferably formed in different regions. The guidewire lumen 30, the first lumen 31, and the second lumen 32 preferably extend in the longitudinal direction x of the balloon catheter 100.

[0025] As shown in Figures 4 to 6, in a cross section perpendicular to the longitudinal direction of the proximal shaft portion 3, the distance between the centroid 30c of the guidewire lumen 30 and the centroid 32c of the second lumen 32 is configured to be longer than the distance between the centroid 30c of the guidewire lumen 30 and the centroid 31c of the first lumen 31.

[0026] By making the distance between the centroid 30c of the guidewire lumen 30 and the centroid 32c of the second lumen 32 longer than the distance between the centroid 30c of the guidewire lumen 30 and the centroid 31c of the first lumen 31, it is possible to prevent the portion between the second lumen 32 and the guidewire lumen 30 from becoming too thin due to the second lumen 32 coming too close to the guidewire lumen 30. This makes it easier to prevent fluid from leaking from the second lumen 32 into the guidewire lumen 30.

[0027] The balloon catheter 100 according to the embodiment 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 100 according to the embodiment of the present invention is preferably used for dilating an aortic valve that has hardened due to calcification or the like, or for deforming or destroying an artificial valve annulus of a biological valve that is placed in the heart and has deteriorated over time to replace the biological valve.

[0028] The balloon catheter 100 has a distal end and a proximal end in its longitudinal direction x.

[0029] The number of balloon portions 10 included in the balloon portion group 1 can be, for example, two or more, three or more, four or more, etc. The number of balloon portions 10 included in the balloon portion group 1 can be, for example, 15 or less, 13 or less, 10 or less, etc. Figures 1 to 3 and 7 show an embodiment in which the balloon portion group 1 includes seven balloon portions 10.

[0030] 2 and 7 , the balloon portion 10 has a distal end 10d and a proximal end 10p in the longitudinal direction x of the balloon catheter 100. The distal end of the balloon portion group 1 coincides with the distal end 10d that is located most distally among the distal ends 10d of the multiple balloon portions 10. The proximal end of the balloon portion group 1 coincides with the proximal end 10p that is located most proximal among the proximal ends 10p of the multiple balloon portions 10.

[0031] Examples of materials that can be used to form the balloon portion 10 include polyamide resins such as nylon 11 and nylon 12, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyurethane resins, thermoplastic elastomers such as polyether block amide copolymers, and combinations of these.

[0032] 2, the balloon portion 10 may have a straight tube portion 10a, a distal tapered portion 10b located distal to the straight tube portion 10a and having an outer diameter that decreases distally, and a proximal tapered portion 10c located proximal to the straight tube portion 10a and having an outer diameter that decreases proximally. Only some of the multiple balloon portions 10 included in the balloon catheter 100 may have the straight tube portion 10a, the distal tapered portion 10b, and the proximal tapered portion 10c. Alternatively, all of the multiple balloon portions 10 included in the balloon catheter 100 may have the straight tube portion 10a, the distal tapered portion 10b, and the proximal tapered portion 10c.

[0033] The straight tube portion 10a may be a hollow cylinder having approximately the same diameter in the longitudinal direction x of the balloon catheter 100, or may have different diameters in the longitudinal direction x of the balloon catheter 100.

[0034] The distal tapered portion 10b and the proximal tapered portion 10c are preferably formed in the shape of a hollow cone or hollow truncated cone whose diameter decreases as it extends away from the straight tube portion 10a.

[0035] As shown in FIGS. 2 and 7, one inner balloon portion 11 has a distal end 11d and a proximal end 11p.

[0036] As shown in Figures 2 and 7, one outer balloon portion 12 has a distal end 12d and a proximal end 12p.

[0037] The number of inner balloon portions 11 can be, for example, one or more, two or more, three or more, etc. The number of inner balloon portions 11 can be, for example, six or less, five or less, four or less, etc. Figures 2, 3, and 7 show an embodiment in which only one inner balloon portion 11 is provided.

[0038] The number of outer balloon portions 12 can be, for example, 1 or more, 2 or more, 3 or more, etc. The number of outer balloon portions 12 can be, for example, 14 or less, 12 or less, 10 or less, etc. Figures 2, 3, and 7 show an embodiment in which six outer balloon portions 12 are provided.

[0039] When a plurality of outer balloon portions 12 are provided, it is preferable that all of the outer balloon portions 12 abut against the inner balloon portion 11. Note that a configuration in which some of the plurality of outer balloon portions 12 abut against the inner balloon portion 11 and the remaining outer balloon portions 12 do not abut against the inner balloon portion 11 is also acceptable. That is, a configuration in which some of the plurality of outer balloon portions 12 abut against the inner balloon portion 11 and the remaining outer balloon portions 12 do not abut against the inner balloon portion 11 but abut against other outer balloon portions 12 is also acceptable.

[0040] The material constituting the inner balloon portion 11 and the material constituting the outer balloon portion 12 may be the same or different.

[0041] A plurality of outer balloon portions 12 may be arranged around the inner balloon portion 11. The inner balloon portion 11 may be located at a position where the central axis of the balloon portion group 1 passes through. The plurality of outer balloon portions 12 may be arranged in the circumferential direction c of the balloon catheter 100.

[0042] A guidewire is inserted into the guidewire tube 13. The guidewire tube 13 has an inner lumen into which the guidewire is inserted. The inner lumen of the guidewire tube 13 preferably extends in the longitudinal direction x of the balloon catheter 100.

[0043] The guidewire tube 13 can be made of any of the materials exemplified as materials for making the proximal shaft portion 3 described later.

[0044] The guidewire tube 13 may have a cylindrical shape, a hollow cylindrical shape, a hollow polygonal prism shape, or the like.

[0045] Radiopaque markers may be placed on the outer surface of the guidewire tube 13 at positions where the inner balloon portion 11 is located in the longitudinal direction x of the balloon catheter 100. The radiopaque markers are preferably placed on the outer surface of the guidewire tube 13 at positions where the distal end of the straight tube portion of the inner balloon portion 11 is located and the proximal end of the straight tube portion of the inner balloon portion 11 is located in the longitudinal direction x of the balloon catheter 100. Alternatively, the radiopaque marker may be placed at a position where the center of the straight tube portion of the inner balloon portion 11 is located in the longitudinal direction x of the balloon catheter 100.

[0046] As shown in Fig. 2, the proximal end 11p of the inner balloon portion 11 may be located at the same position as the proximal end 12p of the outer balloon portion 12 in the longitudinal direction x of the balloon catheter 100. As shown in Fig. 7, the proximal end 11p of the inner balloon portion 11 may be located distal to the proximal end 12p of the outer balloon portion 12. Although not shown, a configuration in which the proximal end 11p of the inner balloon portion 11 is located proximal to the proximal end 12p of the outer balloon portion 12 is also acceptable.

[0047] As shown in Fig. 2, the distal end 11d of the inner balloon portion 11 may be located at the same position as the distal end 12d of the outer balloon portion 12 in the longitudinal direction x of the balloon catheter 100. As shown in Fig. 7, the distal end 11d of the inner balloon portion 11 may be located proximal to the distal end 12d of the outer balloon portion 12. Although not shown, the distal end 11d of the inner balloon portion 11 may be located distal to the distal end 12d of the outer balloon portion 12.

[0048] The proximal shaft portion 3 preferably extends in the longitudinal direction x of the balloon catheter 100 .

[0049] The shape of the proximal shaft portion 3 can be a cylindrical shape, a hollow columnar shape, a hollow polygonal columnar shape, or the like.

[0050] Examples of the proximal shaft portion 3 include a hollow body formed by arranging one or more wires in a predetermined pattern; a hollow body having a resin coating on at least one of the inner and outer surfaces; a resin tube; or a combination of these, such as a combination of these connected in the longitudinal direction. Examples of hollow bodies having wires arranged in a predetermined pattern include a tubular body having a mesh structure formed by crossing or weaving wires, and a coil formed by winding wires. The wires may be one or more solid wires or one or more twisted wires. The resin tube can be manufactured, for example, by extrusion molding. When the proximal shaft portion 3 is a resin tube, it can be composed of a single layer or multiple layers. A portion of the proximal shaft portion 3 in the longitudinal direction x or circumferential direction c of the balloon catheter 100 may be composed of a single layer, and the other portion may be composed of multiple layers.

[0051] The proximal shaft portion 3 can be made of, for example, synthetic resins such as polyolefin resins (e.g., polyethylene and polypropylene), polyamide resins (e.g., nylon), polyester resins (e.g., PET), aromatic polyether ketone resins (e.g., PEEK), polyether polyamide resins, polyurethane resins, polyimide resins, and fluororesins (e.g., PTFE, PFA, and ETFE), or metals such as stainless steel, carbon steel, and nickel-titanium alloys. These may be used alone or in combination of two or more.

[0052] The proximal shaft portion 3 may be made up of only one cylindrical member, or may be made up of multiple cylindrical members.

[0053] The guidewire lumen 30 preferably communicates with the inner cavity of the guidewire tube 13 disposed inside the inner balloon portion 11 .

[0054] The first lumen 31 preferably communicates with the interior of the inner balloon portion 11. The inner balloon portion 11 preferably expands with fluid supplied through the first lumen 31. The inner balloon portion 11 preferably contracts with fluid discharged through the first lumen 31.

[0055] Although a plurality of first lumens 31 may be provided, it is preferable that only one first lumen 31 is provided. It is preferable that the number of first lumens 31 is the same as the number of inner balloon portions 11.

[0056] The second lumen 32 preferably communicates with the interior of the outer balloon portion 12. The outer balloon portion 12 is preferably expanded by fluid supplied via the second lumen 32. The outer balloon portion 12 is preferably deflated by fluid being discharged via the second lumen 32.

[0057] Although only one second lumen 32 may be provided, it is preferable that a plurality of second lumens 32 are provided. The number of second lumens 32 is preferably the same as the number of outer balloon portions 12. In a cross section perpendicular to the longitudinal direction of the proximal shaft portion 3, the distance between the centroid 30c of the guidewire lumen 30 and the centroid 32c of the second lumens 32 is longer than the distance between the centroid 30c of the guidewire lumen 30 and the centroid 31c of the first lumen 31, which makes it easier to arrange the plurality of second lumens 32 concentrically and at equal intervals.

[0058] In a cross section perpendicular to the longitudinal direction of the proximal shaft portion 3 , the second lumen 32 is preferably located radially outward of the proximal shaft portion 3 than the first lumen 31 .

[0059] The outer shapes of the guidewire lumen 30, the first lumen 31, and the second lumen 32 in a cross section perpendicular to the longitudinal direction of the proximal shaft portion 3 may each be circular, polygonal including triangular and rectangular, semicircular, fan-shaped, wedge-shaped, convex, crescent-shaped, or a combination thereof.

[0060] 5 and 6 , the outer shape of the first lumen 31 in a cross section perpendicular to the longitudinal direction of the proximal shaft section 3 may be different from the outer shape of the second lumen 32. In a cross section perpendicular to the longitudinal direction of the proximal shaft section 3, the outer shape of the first lumen 31 may be different from the outer shape of the guidewire lumen 30. In a cross section perpendicular to the longitudinal direction of the proximal shaft section 3, the outer shape of the second lumen 32 may be different from the outer shape of the guidewire lumen 30. In a cross section perpendicular to the longitudinal direction of the proximal shaft section 3, the outer shape of the first lumen 31, the outer shape of the second lumen 32, and the outer diameter of the guidewire lumen 30 may each be different. This configuration makes it easier to reduce the diameter of the proximal shaft section 3.

[0061] 5 and 6, the outer shape of the first lumen 31 is preferably irregular in a cross section perpendicular to the longitudinal direction of the proximal shaft portion 3. An irregular shape means a shape other than a perfect circle, and shapes such as an ellipse or an egg shape are not included in the definition of a perfect circle. Note that although the term "circular shape" may be used in this specification, the term "circular shape" includes shapes such as a perfect circle, an ellipse, and an egg shape.

[0062] 5 , in a cross section perpendicular to the longitudinal direction of the proximal shaft portion 3, the cross-sectional area of ​​the first lumen 31 may be larger than the cross-sectional area of ​​the second lumen 32. This makes it easier to expand the inner balloon portion 11 at an earlier timing than the outer balloon portion 12.

[0063] 4 , in a cross section perpendicular to the longitudinal direction of the proximal shaft portion 3, the cross-sectional area of ​​the second lumen 32 may be larger than the cross-sectional area of ​​the first lumen 31. This makes it easier to expand the outer balloon portion 12 at an earlier timing than the inner balloon portion 11.

[0064] Although not shown, the cross-sectional area of ​​the first lumen 31 and the cross-sectional area of ​​the second lumen 32 may be the same in a cross section perpendicular to the longitudinal direction of the proximal shaft portion 3. This makes it easier to expand the inner balloon portion 11 and the outer balloon portion 12 simultaneously.

[0065] 2, 4, and 6, the proximal shaft portion 3 may include an outer tube 33 having a lumen 331 extending in the longitudinal direction x of the balloon catheter 100, a first tube 34 disposed in the lumen 331 of the outer tube 33, and a second tube 35 disposed in the lumen 331 of the outer tube 33. The second tube 35 is preferably located radially outward of the first tube 34. In a cross section perpendicular to the longitudinal direction of the proximal shaft portion 3, the second tube 35 is preferably located radially outward of the first tube 34.

[0066] The material constituting the outer tube 33, the material constituting the first tube 34, and the material constituting the second tube 35 may be the same or different.

[0067] Preferably, the first tube 34 has a guidewire lumen 30 and a first lumen 31 formed therein, and the second tube 35 has a second lumen 32 formed therein.

[0068] Although multiple first tubes 34 may be provided, only one is preferred. The number of first tubes 34 is preferably the same as the number of inner balloon portions 11. The distal ends of the first tubes 34 are preferably connected to the proximal end of the proximal sleeve portion 5 connected to the inner balloon portion 11. This allows fluid to be supplied to the inside of the inner balloon portion 11 via the first lumen 31 of the first tube 34 and the flow path 6 of the proximal sleeve portion 5, which will be described later.

[0069] Although only one second tube 35 may be provided, it is preferable to provide a plurality of second tubes 35. The number of second tubes 35 is preferably the same as the number of outer balloon portions 12. The distal end of each second tube 35 is preferably connected to the proximal end of the proximal sleeve portion 5 connected to the outer balloon portion 12. This allows fluid to be supplied to the inside of the outer balloon portion 12 via the second lumen 32 of the second tube 35 and the flow path 6 of the proximal sleeve portion 5.

[0070] As shown in FIG. 6 , a filler 36 may be disposed in the space surrounded by the inner surface of the outer tube 33 , the outer surface of the first tube 34 , and the outer surface of the second tube 35 .

[0071] As the filler 36, the materials exemplified as the materials constituting the balloon portion 10 and the proximal shaft portion 3 can be used.

[0072] 4, a gap may exist in the space surrounded by the inner surface of the outer tube 33, the outer surface of the first tube 34, and the outer surface of the second tube 35. The inner surface of the outer tube 33, the outer surface of the first tube 34, and the outer surface of the second tube 35 may be exposed to the gap.

[0073] As shown in FIG. 5 , the proximal shaft portion 3 may be formed of a tubular member 37 having a guidewire lumen 30 through which a guidewire is inserted, a first lumen 31 through which fluid supplied to the inner balloon portion 11 can pass, and a second lumen 32 through which fluid supplied to the outer balloon portion 12 can pass. In this case, it is preferable that the proximal end of the proximal sleeve portion 5 connected to the inner balloon portion 11 is connected to the distal end of the proximal shaft portion 3 so that the flow path 6 of the proximal sleeve portion 5 connected to the inner balloon portion 11 communicates with the first lumen 31. It is also preferable that the proximal end of the proximal sleeve portion 5 connected to the outer balloon portion 12 is connected to the distal end of the proximal shaft portion 3 so that the flow path 6 of the proximal sleeve portion 5 connected to the outer balloon portion 12 communicates with the second lumen 32. With the above configuration, fluid can be supplied to the interior of the inner balloon portion 11 via the first lumen 31 and the flow path 6 of the proximal sleeve portion 5. In addition, fluid can be supplied to the inside of the outer balloon portion 12 via the second lumen 32 and the flow path 6 of the proximal sleeve portion 5.

[0074] 5 and 6 , in a cross section perpendicular to the longitudinal direction of the proximal shaft section 3, the first lumen 31 may be located on a line segment connecting the centroid 30c of the guidewire lumen 30 and the centroid 32c of the second lumen 32. In Figures 5 and 6 , the line segment connecting the centroid 30c of the guidewire lumen 30 and the centroid 32c of the second lumen 32 is indicated by a dashed line. This allows the cross-sectional area of ​​the first lumen 31 to be relatively large in a cross section perpendicular to the longitudinal direction of the proximal shaft section 3, making it easier to expand the inner balloon section 11 at an earlier timing than the outer balloon section 12.

[0075] As shown in Figure 4, in a cross section perpendicular to the longitudinal direction of the proximal shaft section 3, the first lumen 31 does not have to be located on a line segment connecting the centroid 30c of the guidewire lumen 30 and the centroid 32c of the second lumen 32. More specifically, in a cross section perpendicular to the longitudinal direction of the proximal shaft section 3, the first lumen 31 may be located between two line segments connecting the centroid 30c of the guidewire lumen 30 and the centroid 32c of the second lumen 32, which are adjacent to each other in the circumferential direction c of the balloon catheter 100. In Figure 4, the line segment connecting the centroid 30c of the guidewire lumen 30 and the centroid 32c of the second lumen 32 is indicated by a dashed line. This allows the cross-sectional area of ​​the first lumen 31 to be relatively small in a cross section perpendicular to the longitudinal direction of the proximal shaft section 3, making it easier to inflate the outer balloon section 12 at an earlier timing than the inner balloon section 11.

[0076] 4 to 6, in a cross section perpendicular to the longitudinal direction of the proximal shaft section 3, the centroid 30c of the guidewire lumen 30 may be offset from the centroid 3c of the proximal shaft section 3. Although not shown, an embodiment in which the centroid 30c of the guidewire lumen 30 coincides with the centroid 3c of the proximal shaft section 3 in a cross section perpendicular to the longitudinal direction of the proximal shaft section 3 is also acceptable. In a cross section perpendicular to the longitudinal direction of the proximal shaft section 3, the guidewire lumen 30 is preferably formed in a region including the centroid 3c of the proximal shaft section 3.

[0077] As shown in FIGS. 1, 2 and 7, the balloon catheter 100 may have a proximal sleeve portion 5 connecting the balloon portion 10 and the proximal shaft portion 3.

[0078] Although a plurality of proximal sleeve portions 5 may be connected to one balloon portion 10, it is preferable that only one proximal sleeve portion 5 is connected to one balloon portion 10.

[0079] It is preferable that a plurality of proximal sleeve portions 5 are connected to one proximal shaft portion 3 .

[0080] It is preferable that one proximal sleeve portion 5 is connected to one balloon portion 10, and it is more preferable that the distal end portion of one proximal sleeve portion 5 is connected to the proximal end portion of one balloon portion 10. It is also preferable that one proximal shaft portion 3 is connected to a plurality of proximal sleeve portions 5, and it is more preferable that the distal end portion of one proximal shaft portion 3 is connected to the proximal end portions of a plurality of proximal sleeve portions 5.

[0081] 8 and 9, the proximal sleeve portion 5 preferably has a flow path 6 through which a fluid can pass. Although not shown in detail, the flow path 6 preferably communicates from the distal end to the proximal end of the proximal sleeve portion 5. This allows fluid to be supplied to the inside of the balloon portion 10 via the flow path 6 of the proximal sleeve portion 5.

[0082] The shape of the proximal sleeve portion 5 may be a cylinder, a hollow column, a hollow polygonal column, or the like.

[0083] As the material for forming the proximal sleeve portion 5, the materials exemplified as the material for forming the balloon portion 10 and the material for forming the proximal shaft portion 3 can be used.

[0084] As shown in FIGS. 1, 2, and 7, the balloon catheter 100 may have a distal shaft portion 2 located distal to the balloon portion 10.

[0085] As shown in FIG. 1 , the distal shaft portion 2 is a portion located distal to the balloon portion 10 .

[0086] The distal shaft portion 2 preferably extends in the longitudinal direction x of the balloon catheter 100. The distal shaft portion 2 may have a lumen through which the fluid can pass after being supplied to the balloon portion 10, or may not have a lumen through which the fluid can pass after being supplied to the balloon portion 10.

[0087] The shape of the distal shaft portion 2 can be a cylindrical shape, a hollow cylindrical shape, a hollow polygonal prism shape, a conical shape, a truncated conical shape, a tapered shape, or the like.

[0088] As shown in FIG. 1 , in the longitudinal direction x of the balloon catheter 100 , the length of the distal shaft portion 2 is preferably shorter than the length of the proximal shaft portion 3 .

[0089] As the material for forming the distal shaft portion 2, the materials exemplified as the material for forming the proximal shaft portion 3 can be used.

[0090] As shown in Figures 10 to 13, the distal shaft section 2 may be configured to include a guidewire lumen 20 through which a guidewire is inserted. As shown in Figures 10 to 12, the distal shaft section 2 may be configured to include a guidewire lumen 20 through which a guidewire is inserted, a first lumen 21 through which fluid can pass after being supplied to the inner balloon section 11, and a second lumen 22 through which fluid can pass after being supplied to the outer balloon section 12. In this case, it is preferable that the guidewire lumen 20, the first lumen 21, and the second lumen 22 are formed in different regions in a cross section perpendicular to the longitudinal direction x of the balloon catheter 100. From the perspective of ease of diameter reduction, it is preferable that the distal shaft section 2 be configured to include only the guidewire lumen 20 through which a guidewire is inserted, as shown in Figure 13. It is preferable that the guidewire lumen 20, the first lumen 21, and the second lumen 22 extend in the longitudinal direction x of the balloon catheter 100.

[0091] The guidewire lumen 20 preferably communicates with the inner cavity of the guidewire tube 13 disposed inside the inner balloon portion 11 .

[0092] The first lumen 21 may be in communication with the interior of the inner balloon portion 11 .

[0093] The number of first lumens 21 may be the same as the number of inner balloon portions 11.

[0094] The second lumen 22 may be in communication with the interior of the outer balloon portion 12 .

[0095] The number of second lumens 22 may be the same as the number of outer balloon portions 12.

[0096] In a cross section perpendicular to the longitudinal direction of the proximal shaft portion 3 , the second lumen 22 is preferably located radially outward of the proximal shaft portion 3 than the first lumen 21 .

[0097] The outer shapes of the guidewire lumen 20, the first lumen 21, and the second lumen 22 in a cross section perpendicular to the longitudinal direction of the proximal shaft portion 3 may each be circular, polygonal including triangular and rectangular, semicircular, fan-shaped, wedge-shaped, convex, crescent-shaped, or a combination thereof.

[0098] 2, 10, and 12, the distal shaft portion 2 may include an outer tube 23 having a lumen 231 extending in the longitudinal direction x of the balloon catheter 100, a first tube 24 disposed in the lumen 231 of the outer tube 23, and a second tube 25 disposed in the lumen 231 of the outer tube 23. In a cross section perpendicular to the longitudinal direction of the proximal shaft portion 3, the second tube 25 is preferably located radially outward of the proximal shaft portion 3 relative to the first tube 24.

[0099] The material constituting the outer tube 23, the material constituting the first tube 24, and the material constituting the second tube 25 may be the same or different.

[0100] The first tube 24 may have a guidewire lumen 20 and a first lumen 21 formed therein, and the second tube 25 may have a second lumen 22 formed therein.

[0101] A plurality of first tubes 24 may be provided, or only one may be provided. The number of first tubes 24 may be the same as the number of inner balloon portions 11. The proximal end of each first tube 24 may be connected to the distal end of the distal sleeve portion 4 connected to the inner balloon portion 11. This allows fluid to be supplied from the inner balloon portion 11 to the first lumen 21 of the first tube 24 via a flow path 6 of the distal sleeve portion 4, which will be described later.

[0102] Only one second tube 25 may be provided, or multiple second tubes 25 may be provided. The number of second tubes 25 may be the same as the number of outer balloon portions 12. The proximal end of the second tube 25 may be connected to the distal end of the distal sleeve portion 4 connected to the outer balloon portion 12. This allows fluid to be supplied from the outer balloon portion 12 to the second lumen 22 of the second tube 25 via the flow path 6 of the distal sleeve portion 4.

[0103] As shown in FIG. 12 , a filler 26 may be disposed in the space surrounded by the inner surface of the outer tube 23 , the outer surface of the first tube 24 , and the outer surface of the second tube 25 .

[0104] As the filler 26, the materials exemplified as the materials constituting the balloon portion 10 and the proximal shaft portion 3 can be used.

[0105] 10 , a gap may exist in the space surrounded by the inner surface of the outer tube 23, the outer surface of the first tube 24, and the outer surface of the second tube 25. The inner surface of the outer tube 23, the outer surface of the first tube 24, and the outer surface of the second tube 25 may be exposed to the gap.

[0106] 11 , the distal shaft portion 2 may be formed of a tubular member 27 having a guidewire lumen 20 through which a guidewire is inserted, a first lumen 21 through which fluid can pass after being supplied to the inner balloon portion 11, and a second lumen 22 through which fluid can pass after being supplied to the outer balloon portion 12. In this case, the distal end of the distal sleeve portion 4 connected to the inner balloon portion 11 may be connected to the proximal end of the distal shaft portion 2 so that the flow path 6 of the distal sleeve portion 4 connected to the inner balloon portion 11 communicates with the first lumen 21. Preferably, the distal end of the distal sleeve portion 4 connected to the outer balloon portion 12 is connected to the proximal end of the distal shaft portion 2 so that the flow path 6 of the distal sleeve portion 4 connected to the outer balloon portion 12 communicates with the second lumen 22. With the above configuration, the fluid supplied to the inner balloon portion 11 is supplied to the first lumen 21 via the flow path 6 of the distal sleeve portion 4. Furthermore, the fluid supplied to the outer balloon portion 12 is supplied to the second lumen 22 via the flow path 6 of the distal sleeve portion 4 .

[0107] The guidewire lumen 20 preferably passes through the balloon catheter 100 in the longitudinal direction x.

[0108] The first lumen 21 and the second lumen 22 preferably have open proximal ends and closed distal ends. That is, it is preferable that no fluid is supplied distal to the distal shaft portion 2. This makes it easier for fluid to accumulate inside the balloon portion 10, making it easier for the balloon portion 10 to expand.

[0109] As shown in FIGS. 1, 2 and 7, the balloon catheter 100 may have a distal sleeve portion 4 connecting the balloon portion 10 and the distal shaft portion 2.

[0110] A plurality of distal sleeve portions 4 may be connected to one balloon portion 10, but it is preferable that only one distal sleeve portion 4 is connected to one balloon portion 10.

[0111] It is preferable that a plurality of distal sleeve portions 4 are connected to one distal shaft portion 2 .

[0112] It is preferable that one distal sleeve portion 4 is connected to one balloon portion 10, and it is more preferable that the proximal end portion of one distal sleeve portion 4 is connected to the distal end portion of one balloon portion 10. It is also preferable that one distal shaft portion 2 is connected to a plurality of distal sleeve portions 4, and it is more preferable that the proximal end portion of one distal shaft portion 2 is connected to the distal end portions of a plurality of distal sleeve portions 4.

[0113] 8, the distal sleeve portion 4 may have a flow path 6 through which a fluid can pass. Although not shown in detail, the flow path 6 may communicate from the distal end to the proximal end of the distal sleeve portion 4. The flow path 6 may also be present in only a portion of the distal sleeve portion 4 from the distal end to the proximal end.

[0114] 9, the distal sleeve portion 4 does not have to have a flow path 6 through which a fluid can pass. This makes it easier to reduce the diameter of the distal sleeve portion 4.

[0115] The distal sleeve portion 4 may have a cylindrical shape, a polygonal prism shape, a tube shape, a hollow cylindrical shape, a hollow polygonal prism shape, or the like.

[0116] As the material for forming the distal sleeve portion 4, the materials exemplified as the material for forming the balloon portion 10 and the material for forming the proximal shaft portion 3 can be used.

[0117] As shown in Fig. 1, a hub 7 may be connected to the proximal portion of the proximal shaft portion 3. Although not shown, the hub 7 may have a bifurcated structure. The hub 7 may also be provided with a fluid injection portion 8 that can inject a fluid to be supplied inside the balloon portion 10. The fluid injection portion 8 is preferably connected to the indeflator described above.

[0118] The proximal shaft portion 3 and the hub 7 may be fixed to each other. For example, the proximal shaft portion 3 and the hub 7 can be fixed to each other by adhesive bonding, welding, screws, or the like. Among these, the proximal shaft portion 3 and the hub 7 are preferably fixed to each other by adhesive bonding. By fixing the proximal shaft portion 3 and the hub 7 to each other by adhesive bonding, the strength of the connection between the proximal shaft portion 3 and the hub 7 can be increased even when the proximal shaft portion 3 and the hub 7 are made of different materials, for example, when the proximal shaft portion 3 is made of a highly flexible material and the hub 7 is made of a highly rigid material. This makes it easier to improve the durability of the balloon catheter 100.

[0119] FIG. 1 discloses an embodiment in which a guidewire port 9 is formed midway between the distal end and the proximal end of the proximal shaft portion 3. The guidewire port 9 is in communication with the guidewire lumen 30 of the proximal shaft portion 3. FIG. 1 illustrates a so-called rapid exchange balloon catheter 100. The proximal shaft portion 3 may include a first proximal shaft portion 3a and a second proximal shaft portion 3b located distal to the first proximal shaft portion 3a. The first proximal shaft portion 3a and the second proximal shaft portion 3b may be separate members, with the distal end of the member constituting the first proximal shaft portion 3a connected to the proximal end of the member constituting the second proximal shaft portion 3b. Alternatively, the first proximal shaft portion 3a and the second proximal shaft portion 3b may be formed from a single member.

[0120] 2 , the proximal end of the guidewire tube 13 is preferably connected to the distal end of the proximal shaft portion 3. The proximal end of the guidewire tube 13 and the distal end of the proximal shaft portion 3 may be connected directly without any other member therebetween, or may be connected indirectly via another member. When the proximal shaft portion 3 has a first proximal shaft portion 3 a and a second proximal shaft portion 3 b, the proximal end of the guidewire tube 13 is preferably connected to the distal end of the second proximal shaft portion 3 b.

[0121] 2, the distal end of the guidewire tube 13 is preferably connected to the proximal end of the distal shaft portion 2. The distal end of the guidewire tube 13 and the proximal end of the distal shaft portion 2 may be connected directly without any other member therebetween, or may be connected indirectly via another member.

[0122] Although not shown, the balloon catheter 100 may be of a so-called over-the-wire type, in which the guidewire lumen 30 is formed from the distal end to the proximal end of the proximal shaft 3. When the balloon catheter 100 is of an over-the-wire type, the guidewire lumen 30 of the proximal shaft 3 preferably extends in the longitudinal direction x of the balloon catheter 100 to the position where the hub 7 is located. The first lumen 31 and the second lumen 32 of the proximal shaft 3 preferably extend partway from the distal end to the proximal end of the proximal shaft 3. The proximal ends of the first lumen 31 and the second lumen 32 of the proximal shaft 3 are preferably located distal to the distal end of the hub 7. Note that the first lumen 31 and the second lumen 32 of the proximal shaft 3 may also extend in the longitudinal direction x of the balloon catheter 100 to the position where the hub 7 is located.

[0123] The outer surface of the proximal shaft portion 3 and the outer surface of the distal shaft portion 2 may be coated. As shown in FIG. 1 , when the balloon catheter 100 is a rapid exchange type, the outer surface of at least one of the first proximal shaft portion 3 a and the second proximal shaft portion 3 b may be coated, or the outer surfaces of both the first proximal shaft portion 3 a and the second proximal shaft portion 3 b may be coated. When the balloon catheter 100 is an over-the-wire type, only a portion or the entire outer surface of the proximal shaft portion 3 may be coated. Only a portion or the entire outer surface of the distal shaft portion 2 may be coated.

[0124] The coating applied to the outer surface of the proximal shaft portion 3 or the outer surface of the distal shaft portion 2 can be a hydrophilic coating or a hydrophobic coating depending on the purpose. The coating can be applied by immersing the proximal shaft portion 3 or the distal shaft portion 2 in a hydrophilic or hydrophobic coating agent, by applying a hydrophilic or hydrophobic coating agent to the outer surface of the proximal shaft portion 3 or the distal shaft portion 2, or by covering the outer surface of the proximal shaft portion 3 or the distal shaft portion 2 with a hydrophilic or hydrophobic coating agent. Drugs or additives may be added to the coating agent.

[0125] Examples of hydrophilic coating agents include hydrophilic polymers such as polyvinyl alcohol, polyethylene glycol, polyacrylamide, polyvinylpyrrolidone, and methyl vinyl ether-maleic anhydride copolymer, and hydrophilic coating agents composed of combinations of these.

[0126] 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.

[0127] This application claims the benefit of priority based on Japanese Patent Application No. 2024-003248, filed on January 12, 2024. The entire contents of the specification of Japanese Patent Application No. 2024-003248, filed on January 12, 2024, are incorporated herein by reference.

[0128] 1: Balloon section group 10: Balloon section 10a: Straight tube section 10b: Distal tapered section 10c: Proximal tapered section 10d: Distal end 10p: Proximal end 11: Inner balloon section 11d: Distal end 11p: Proximal end 12: Outer balloon section 12d: Distal end 12p: Proximal end 13: Guidewire tube 2: Distal shaft section 20: Guidewire lumen 21: First lumen 22: Second lumen 23: Outer tube 231: Inner cavity 24: First tube 25: Second tube 26: Filler material 27: Cylindrical member 3: Proximal shaft section 3a: First proximal shaft section 3b: Second proximal shaft section 3c: Centroid of proximal shaft section 30: Guidewire lumen 30c: Centroid of guidewire lumen 31: First lumen 31c: Centroid of first lumen 32: Second lumen 32c: Centroid of second lumen 33: Outer tube 331: Inner cavity 34: First tube 35: Second tube 36: Filler material 37: Cylindrical member 4: Distal sleeve portion 5: Proximal sleeve portion 6: Flow path 7: Hub 8: Fluid injection portion 9: Guidewire port 100: Balloon catheter x: Longitudinal direction of balloon catheter y: Radial direction of balloon catheter c: Circumferential direction of balloon catheter

Claims

1. A balloon catheter having a balloon portion group including a plurality of juxtaposed balloon portions and a proximal shaft portion located proximal to the balloon portion, the balloon portion group including an inner balloon portion provided with a guide wire tube into which a guide wire is inserted and an outer balloon portion located radially outward of the inner balloon portion, the proximal shaft portion having a guide wire lumen into which the guide wire is inserted, a first lumen through which fluid supplied to the inner balloon portion can pass, and a second lumen through which fluid supplied to the outer balloon portion can pass, and in a cross section perpendicular to the longitudinal direction of the proximal shaft portion, the distance between the centroid of the guide wire lumen and the centroid of the second lumen is longer than the distance between the centroid of the guide wire lumen and the centroid of the first lumen.

2. The balloon catheter according to claim 1, wherein in a cross section perpendicular to the longitudinal direction of the proximal shaft portion, the first lumen is present on a line segment connecting the centroid of the guide wire lumen and the centroid of the second lumen.

3. The balloon catheter according to claim 1, wherein in a cross section perpendicular to the longitudinal direction of the proximal shaft portion, the first lumen is not present on a line segment connecting the centroid of the guide wire lumen and the centroid of the second lumen.

4. The balloon catheter according to claim 1, wherein in a cross section perpendicular to the longitudinal direction of the proximal shaft portion, the centroid of the guide wire lumen is offset from the centroid of the proximal shaft portion.

5. The balloon catheter according to claim 1, wherein in a cross section perpendicular to the longitudinal direction of the proximal shaft portion, the outer shape of the first lumen has a shape different from the outer shape of the second lumen.

6. The balloon catheter according to claim 1, wherein in a cross section perpendicular to the longitudinal direction of the proximal shaft portion, the outer shape of the first lumen is irregular.

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

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

9. The balloon catheter according to claim 1, having a proximal sleeve portion connecting the balloon portion and the proximal shaft portion, wherein the proximal sleeve portion has a fluid-permeable flow path.

10. The balloon catheter according to any one of claims 1 to 9, having a distal shaft portion located distally of the balloon portion and a distal sleeve portion connecting the balloon portion and the distal shaft portion.

11. The balloon catheter according to claim 10, wherein the distal sleeve portion has a fluid-permeable flow path.

12. The balloon catheter according to claim 10, wherein the distal sleeve portion does not have a fluid-permeable flow path.

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