Catheter

Abstract

A catheter (100) comprises: a first shaft (10); a tip member (20) that comprises a spiral part (21) that has an x-ray-impermeable part (25); a second shaft (50); and a balloon (60) that has a body part (61) that expands and contracts in the radial direction (y) of the first shaft (10). The length to which the body part (61) protrudes from the first shaft (10) can be adjusted in accordance with the length of a lesion of a patient. At least a portion of the spiral part (21) is further to the distal side than a distal end (10d) of the first shaft (10), and the inner diameter of the spiral part (21) can expand with the expansion of the balloon (60).

Description

catheter

[0001] The present invention relates to a catheter.

[0002] Catheters have been developed that have an expansion member that can adjust the length of the portion that expands outside the sheath to match the length of the lesion by adjusting the length of the portion that protrudes from the sheath. Such catheters can perform treatment on the lesion by adjusting the length of the portion that expands outside the sheath to match the length of the lesion.

[0003] For example, US Pat. No. 6,299,649 discloses a catheter assembly having a sheath with an expansion member disposed therein and a flexible distal tip.

[0004] US Patent No. 5,949,999 discloses a catheter having an outer sleeve with a balloon disposed therein and a flexible distal end.

[0005] US Patent No. 5,949,999 discloses a catheter having an outer sheath with an expansion member disposed therein and a flexible distal end.

[0006] US Patent No. 6,884,257 US Patent No. 5,961,536 JP Patent Publication No. 2010-527695

[0007] However, with the catheters described in Patent Documents 1 to 3, it is difficult to visually confirm the shape of the proximal end of the balloon portion that expands outside the sheath, even under X-ray fluoroscopy. This can make it difficult to adjust the length of the portion that expands outside the sheath to the length of the lesion or to properly position the portion that expands outside the sheath at the lesion, which can result in damage to normal tissue when treatment is performed on areas other than the lesion.

[0008] The present invention has been made in consideration of the above circumstances, and its purpose is to provide a catheter that can more easily prevent damage to normal tissue when treatment is performed on areas other than the lesion.

[0009] A catheter according to one embodiment of the present invention is as follows: [1] A catheter comprising: a first shaft having a longitudinal direction and a radial direction and a lumen extending in the longitudinal direction, a tip member connected to a distal end of the first shaft, having a lumen communicating with the lumen of the first shaft, and comprising a spiral portion having a radiopaque portion, a second shaft disposed in the lumen of the first shaft and the lumen of the tip member and moving in the longitudinal direction relative to the first shaft, and a balloon disposed in a distal portion of the second shaft, the balloon having a main body portion that expands and contracts in the radial direction, the length of the main body portion protruding from the first shaft being adjustable depending on the length of a lesion in a patient, wherein at least a portion of the spiral portion is disposed distal to the distal end of the first shaft, and the inner diameter of the spiral portion is expandable by expanding the balloon.

[0010] The expansion of the balloon causes the inner diameter of the spiral portion to expand, allowing the spiral portion to more easily conform to the shape of the proximal end of the main body portion that expands outside the first shaft. Because the spiral portion has a radiopaque portion, the shape of the proximal end of the main body portion that expands outside the first shaft can be easily visualized under X-ray fluoroscopy. This makes it easier to adjust the length of the main body portion that expands outside the first shaft to the length of the lesion and to appropriately position the main body portion that expands outside the first shaft at the lesion. This makes it easier to prevent damage to normal tissue caused by treatment being performed on areas other than the lesion.

[0011] A catheter according to an embodiment of the present invention is preferably any one of the following [2] to

[13] . [2] The catheter according to [1], wherein the tip member has a fixed portion at its proximal portion, the inner diameter of which does not expand when the balloon is expanded, and which is fixed to the first shaft. [3] The catheter according to [1] or [2], wherein the tip member has an outer membrane arranged radially outward of the spiral portion and made of a material having lower rigidity than the material constituting the spiral portion. [4] The catheter according to any one of [1] to [3], wherein, when the balloon is deflated, the balloon has a plurality of blades, and the blades are wound around the second shaft in the circumferential direction of the second shaft, and the winding direction of the spiral of the spiral portion and the winding direction of the blades are the same in the circumferential direction of the second shaft. [5] The catheter according to any one of [1] to [4], wherein, when the balloon is inflated, the portion of the main body protruding from the first shaft has a straight tubular section, a distal tapered section located distal to the straight tubular section, and a proximal tapered section located proximal to the straight tubular section, and when the balloon is inflated, the helical section has an abutting section abutting the straight tubular section. [6] The catheter according to any one of [1] to [5], wherein the first shaft has a convex section protruding radially inward. [7] The catheter according to any one of [1] to [6], wherein the helical section is made of a material containing a shape memory alloy. [8] The catheter according to any one of [1] to [7], wherein, when the balloon is deflated, the helical pitch of the helical section increases toward the distal side. [9] The catheter according to any one of [1] to [8], wherein, in a cross section perpendicular to the longitudinal direction, the cross-sectional area of ​​the helical section decreases toward the distal side.

[10] The catheter according to any one of [1] to [9], wherein the tip member comprises a plurality of the helical portions, the tip member having a helical section in the longitudinal direction comprising the helical portions, and the number of the helical portions present in a proximal portion of the helical section is greater than the number of the helical portions present in a distal portion of the helical section.

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

[10] , wherein the tip member comprises a plurality of the helical portions, the plurality of helical portions including a first helical portion and a second helical portion whose distal end is located proximal to the distal end of the first helical portion.

[12] The catheter according to [2], wherein the inner diameter of a portion of the first shaft when the balloon is inflated is larger than the inner diameter of the portion of the first shaft when the balloon is deflated, and the inner diameter of the fixing part when the balloon is inflated is smaller than the inner diameter of the portion of the first shaft when the balloon is inflated.

[13] The catheter according to

[12] , wherein the first shaft has an outer layer and an inner layer located radially inward from the outer layer, and the inner layer is made of a material having a lower hardness than the outer layer.

[0012] A catheter according to one embodiment of the present invention is as follows:

[14] A catheter comprising: a first shaft having a longitudinal direction and a radial direction and having a lumen extending in the longitudinal direction; a tip member connected to a distal end of the first shaft, having a lumen communicating with the lumen of the first shaft, and having a braided section including a braided section having a radiopaque portion in the longitudinal direction; a second shaft disposed in the lumen of the first shaft and the lumen of the tip member and moving in the longitudinal direction relative to the first shaft; and a balloon disposed in a distal portion of the second shaft, having a main body portion that expands and contracts in the radial direction, the length of protrusion of the main body portion from the first shaft being adjustable depending on the length of a lesion in a patient, wherein at least a portion of the braided section is disposed distal to the distal end of the first shaft, and the inner diameter of the braided section is expandable by expanding the balloon.

[0013] The expansion of the balloon causes the inner diameter of the braided section to expand, which makes it easier for the braided section to conform to the shape of the proximal end of the main body portion expanding outside the first shaft. Because the braided section of the braided section has a radiopaque portion, the shape of the proximal end of the main body portion expanding outside the first shaft can be easily visualized under X-ray fluoroscopy. This makes it easier to adjust the length of the main body portion expanding outside the first shaft to the length of the lesion and to appropriately position the main body portion expanding outside the first shaft at the lesion. This makes it easier to prevent damage to normal tissue caused by treatment being performed on areas other than the lesion.

[0014] A catheter according to an embodiment of the present invention is preferably any one of the following

[15] to

[25] .

[15] The catheter according to

[14] , wherein the tip member has, at its proximal portion, a fixed portion whose inner diameter does not expand when the balloon is expanded and which is fixed to the first shaft.

[16] The catheter according to

[14] or

[15] , wherein the tip member has an outer membrane arranged radially outward of the braided portion and made of a material having lower rigidity than the material constituting the braided portion.

[17] The catheter according to any one of

[14] to

[16] , wherein, when the balloon is inflated, the portion of the main body portion protruding from the first shaft has a straight tube portion, a distal tapered portion located distal to the straight tube portion, and a proximal tapered portion located proximal to the straight tube portion, and when the balloon is inflated, the braided section has an abutting portion that abuts against the straight tube portion.

[18] The catheter according to any one of

[14] to

[17] , wherein the first shaft has a protrusion protruding radially inward.

[19] The catheter according to any one of

[14] to

[18] , wherein the braided portion is made of a material containing a shape memory alloy.

[20] The catheter according to any one of

[14] to

[19] , wherein the braid pitch of the braided portion increases toward the distal side when the balloon is deflated.

[21] The catheter according to any one of

[14] to

[20] , wherein the braided portion has a plurality of wires, and in a cross section perpendicular to the longitudinal direction, the cross-sectional area of ​​the wires decreases toward the distal side.

[22] The catheter according to any one of

[14] to

[21] , wherein the braided portion has a plurality of wires, and the number of the wires present in a proximal portion of the braided portion is greater than the number of the wires present in a distal portion of the braided portion.

[23] A catheter described in any one of

[14] to

[22] , wherein the braided portion has a plurality of wires, and the plurality of wires includes a first wire and a second wire whose distal end is located proximal to the distal end of the first wire.

[24] The catheter according to

[15] , wherein an inner diameter of a portion of the first shaft when the balloon is inflated is larger than an inner diameter of the portion of the first shaft when the balloon is deflated, and an inner diameter of the fixing part when the balloon is inflated is smaller than an inner diameter of the portion of the first shaft when the balloon is inflated.

[25] The catheter according to

[24] , wherein the first shaft has an outer layer and an inner layer located radially inward from the outer layer, and the inner layer is made of a material having a lower hardness than the outer layer.

[0015] A catheter according to one embodiment of the present invention is as follows:

[26] A catheter comprising: a first shaft having a longitudinal direction and a radial direction and having a lumen extending in the longitudinal direction, a tip member connected to a distal end of the first shaft, having a lumen communicating with the lumen of the first shaft, and having a mesh section provided with a mesh section having a radiopaque portion in the longitudinal direction, a second shaft disposed in the lumen of the first shaft and the lumen of the tip member and moving in the longitudinal direction relative to the first shaft, and a balloon disposed in a distal portion of the second shaft, having a main body portion that expands and contracts in the radial direction, the main body portion protruding by a length from the first shaft being adjustable depending on the length of a lesion in a patient, wherein the mesh section has a plurality of openings radially communicating between the outside of the tip member and the lumen of the tip member, at least a portion of the mesh section is disposed distal to the distal end of the first shaft, and the inner diameter of the mesh section is expandable by expanding the balloon.

[0016] The expansion of the balloon causes the inner diameter of the braided section to expand, allowing the braided section to more easily conform to the shape of the proximal end of the main body section that expands outside the first shaft. Because the braided section has a radiopaque portion, the shape of the proximal end of the main body section that expands outside the first shaft can be easily visualized under X-ray fluoroscopy. This makes it easier to adjust the length of the main body section that expands outside the first shaft to the length of the lesion and to appropriately position the main body section that expands outside the first shaft at the lesion. This makes it easier to prevent damage to normal tissue caused by treatment being performed on areas other than the lesion.

[0017] A catheter according to an embodiment of the present invention is preferably any one of the following

[27] to

[35] .

[27] The catheter according to

[26] , wherein the tip member has, at its proximal portion, a fixed portion whose inner diameter does not expand when the balloon is expanded and which is fixed to the first shaft.

[28] The catheter according to

[26] or

[27] , wherein the tip member has an outer membrane arranged radially outward of the mesh portion and made of a material having lower rigidity than the material constituting the mesh portion.

[29] The catheter according to any one of

[26] to

[28] , wherein, when the balloon is expanded, the portion of the main body protruding from the first shaft has a straight tube portion, a distal tapered portion located distal to the straight tube portion, and a proximal tapered portion located proximal to the straight tube portion, and when the balloon is expanded, the mesh section has an abutting portion that abuts against the straight tube portion.

[30] The catheter according to any one of

[26] to

[29] , wherein the first shaft has a convex portion protruding radially inward.

[31] The catheter according to any one of

[26] to

[30] , wherein the mesh portion is made of a material containing a shape memory alloy.

[32] The catheter according to any one of

[26] to

[31] , wherein the mesh portion comprises a linear portion connected to a proximal end of the radiopaque portion and forming a mesh, and wherein the length of the radiopaque portion in the radial direction is longer than the length of the linear portion in the radial direction.

[33] The catheter according to any one of

[26] to

[32] , wherein, when the balloon is deflated, the average area of ​​the openings located in a distal portion of the mesh portion is larger than the average area of ​​the openings located in a proximal portion of the mesh portion.

[34] The catheter according to

[27] , wherein the inner diameter of a portion of the first shaft when the balloon is inflated is larger than the inner diameter of the portion of the first shaft when the balloon is inflated, and the inner diameter of the fixing part when the balloon is inflated is smaller than the inner diameter of the portion of the first shaft when the balloon is inflated.

[35] The catheter according to

[34] , wherein the first shaft has an outer layer and an inner layer located radially inward from the outer layer, and the inner layer is made of a material having a lower hardness than the outer layer.

[0018] The catheter of the present invention can easily prevent damage to normal tissues caused by treatment of areas other than the lesion.

[0019] FIG. 1 is a side view of a catheter according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view (partial side view) of the distal portion of the catheter shown in FIG. 1. FIG. 3 is a cross-sectional view (partial side view) of the catheter shown in FIG. 2, showing a state in which a portion of the main body is expanded outside the first shaft. FIG. 4 is a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 3. FIG. 5 is a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 2. FIG. 6 is a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 5, showing a state in which a portion of the main body is expanded outside the first shaft. FIG. 7 is a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 3. FIG. 8 is a perspective view of a modified example of a tip member. FIG. 9 is a side view of a modified example of a tip member. FIG. 10 is a perspective view of a balloon provided in the catheter shown in FIG. 2. FIG. 11 is a side view of a catheter according to an embodiment of the present invention. FIG. 12 is an enlarged cross-sectional view (partial side view) of the distal portion of the catheter shown in FIG. 11. Fig. 13 is a cross-sectional view (partially side view) of the catheter shown in Fig. 12 , showing a state in which a portion of the main body portion is expanded outside the first shaft. Fig. 14 is a cross-sectional view (partially side view) of a modified example of the catheter shown in Fig. 13 . Fig. 15 is a cross-sectional view (partially side view) of a modified example of the catheter shown in Fig. 12 . Fig. 16 is a cross-sectional view (partially side view) of the catheter shown in Fig. 15 , showing a state in which a portion of the main body portion is expanded outside the first shaft. Fig. 17 is a cross-sectional view (partially side view) of a modified example of the catheter shown in Fig. 13 . Fig. 18 is a side view of a modified example of a tip member. Fig. 19 is a side view of a modified example of a tip member. Fig. 20 is a side view of a catheter according to an embodiment of the present invention. Fig. 21 is an enlarged cross-sectional view (partially side view) of the distal portion of the catheter shown in Fig. 20 . Fig. 22 is a cross-sectional view (partially side view) of the catheter shown in Fig. 21 , showing a state in which a portion of the main body portion is expanded outside the first shaft. Fig. 23 is a cross-sectional view (partially a side view) showing a modified example of the catheter shown in Fig. 22. Fig. 24 is a cross-sectional view (partially a side view) showing a modified example of the catheter shown in Fig. 21. Fig. 25 is a cross-sectional view (partially a side view) showing the catheter shown in Fig. 24 in a state where a portion of the main body portion is expanded outside the first shaft.Fig. 26 is a cross-sectional view (partial side view) showing a modification of the catheter shown in Fig. 22. Fig. 27 is a side view showing a modification of the tip member.

[0020] 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.

[0021] (Embodiment 1)

[0022] A catheter according to one embodiment of the present invention comprises a first shaft having a longitudinal direction and a radial direction and an inner lumen extending in the longitudinal direction; a tip member connected to the distal end of the first shaft, having an inner lumen communicating with the inner lumen of the first shaft, and equipped with a spiral portion having an X-ray opaque portion; a second shaft disposed in the lumen of the first shaft and the inner lumen of the tip member and moving in the longitudinal direction of the first shaft relative to the first shaft; and a balloon disposed in the distal portion of the second shaft, having a main body portion that expands and contracts in the radial direction of the first shaft, and the length of protrusion of the main body portion from the first shaft can be adjusted depending on the length of the lesion in the patient, wherein at least a portion of the spiral portion is disposed distal to the distal end of the first shaft, and the inner diameter of the spiral portion can be expanded by expanding the balloon.

[0023] The overall configuration of a catheter 100 according to an embodiment of the present invention will be described with reference to Figures 1 to 10. The figures show the catheter 100 including a first shaft 10, a tip member 20, a second shaft 50, and a balloon 60. The first shaft 10 has a longitudinal direction x, a radial direction y, and a circumferential direction c.

[0024] Members and parts of the catheter 100 other than the first shaft 10 also have longitudinal, radial, and circumferential directions. The longitudinal, radial, and circumferential directions of members and parts of the catheter 100 other than the first shaft 10 may or may not match the longitudinal direction x, radial direction y, and circumferential direction c of the first shaft 10. For ease of understanding, this specification shows an embodiment in which the longitudinal, radial, and circumferential directions of all members and parts match the longitudinal direction x, radial direction y, and circumferential direction c of the first shaft 10, respectively.

[0025] In this specification, the proximal side refers to the direction toward the user's hand in the longitudinal direction x of the first shaft 10, and the distal side refers to the opposite side of the proximal side, i.e., the direction toward the treatment target. Furthermore, when each member or part is divided into two equal halves in the longitudinal direction x of the first shaft 10, the distal portion of each member or part is referred to as the distal part of each member or part, and the proximal portion of each member or part is referred to as the proximal portion of each member or part. The distal end of each member or part is the end located most distally of each member or part. The proximal end of each member or part is the end located most proximal of each member 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.

[0026] FIG. 1 is a side view of a catheter according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view (partial side view) of the distal portion of the catheter shown in FIG. 1. FIG. 3 is a cross-sectional view (partial side view) of the catheter shown in FIG. 2, showing a state in which a portion of the main body is expanded outside the first shaft. FIG. 4 is a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 3. FIG. 5 is a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 2. FIG. 6 is a cross-sectional view (partial side view) of the catheter shown in FIG. 5, showing a state in which a portion of the main body is expanded outside the first shaft. FIG. 7 is a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 3. More specifically, FIGS. 2 to 7 show cross sections passing through the central axis of the first shaft and parallel to the longitudinal direction of the first shaft. FIG. 8 is a perspective view of a modified example of a tip member. FIG. 9 is a side view of a modified example of a tip member. FIG. 10 is a perspective view of a balloon provided in the catheter shown in FIG. 2.

[0027] As shown in FIGS. 1 to 7, the catheter 100 includes a first shaft 10, a tip member 20, a second shaft 50, and a balloon 60.

[0028] 2 to 7, the first shaft 10 has a longitudinal direction x and a radial direction y, and has a lumen 10a extending in the longitudinal direction x. The first shaft 10 may have an inner surface 10b facing the lumen 10a and an outer surface 10c facing the exterior of the first shaft 10. The first shaft 10 also preferably has a distal end 10d and a proximal end.

[0029] 1 to 9, the tip member 20 is connected to the distal end of the first shaft 10 and has a lumen 20a that communicates with the lumen 10a of the first shaft 10. The tip member 20 may have an inner surface 20b that faces the lumen 20a and an outer surface 20c that faces the exterior of the tip member 20. The lumen 20a of the tip member 20 preferably extends in the longitudinal direction x of the first shaft 10. The tip member 20 also preferably has a distal end 20d and a proximal end 20e.

[0030] The tip member 20 includes a spiral portion 21 having an X-ray opaque portion 25 .

[0031] The spiral portion 21 is preferably a portion configured to wind around the inner cavity 20 a of the tip member 20 .

[0032] As shown in Fig. 9, only a portion of the spiral portion 21 may be formed from a material containing a radiopaque substance to form the radiopaque portion 25. As shown in Fig. 2, the entire spiral portion 21 may be formed from a material containing a radiopaque substance to form the radiopaque portion 25.

[0033] As shown in FIGS. 2 to 7, the second shaft 50 is disposed in the lumen 10a of the first shaft 10 and the lumen 20a of the tip member 20, and moves relative to the first shaft 10 in the longitudinal direction x of the first shaft 10.

[0034] 2 to 7 , the balloon 60 is disposed at the distal portion of the second shaft 50 and has a main body 61 that expands and contracts in the radial direction y of the first shaft 10, and the length of the main body 61 protruding from the first shaft 10 can be adjusted depending on the length of the lesion in the patient. More specifically, it is preferable that the length of the main body 61 protruding from the first shaft 10 can be adjusted by moving the second shaft 50 relative to the first shaft 10 in the longitudinal direction x of the first shaft 10.

[0035] 2 to 7 , at least a portion of the spiral portion 21 is disposed distal to the distal end 10d of the first shaft 10. The entire spiral portion 21 may be disposed distal to the distal end 10d of the first shaft 10. Although not shown, only a portion of the spiral portion 21 may be disposed distal to the distal end 10d of the first shaft 10, with the remaining portion of the spiral portion 21 being disposed proximal to the distal end 10d of the first shaft 10.

[0036] As shown in Figures 2 to 7, the inner diameter of the spiral portion 21 can be expanded by expanding the balloon 60. Figures 2 and 5 show a state in which the balloon 60 is deflated. Figures 3, 4, 6, and 7 show a state in which the balloon 60 is expanded and the inner diameter of the spiral portion 21 is expanded. The inner diameter of only a portion of the spiral portion 21 may be expanded, or the inner diameter of the entire spiral portion 21 may be expanded.

[0037] 2 to 7 , the expansion of the balloon 60 causes the inner diameter of the spiral portion 21 to expand, which allows the spiral portion 21 to more easily conform to the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10. Because the spiral portion 21 has the radiopaque portion 25, the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10 can be easily visualized under X-ray fluoroscopy. This makes it easy to adjust the length of the main body portion 61 expanding outside the first shaft 10 to the length of the lesion, and to appropriately position the main body portion 61 expanding outside the first shaft 10 at the lesion. This makes it easier to prevent damage to normal tissue caused by treatment being performed on areas other than the lesion.

[0038] The catheter 100 can be used, for example, by inserting the distal end of the first shaft 10 to the lesion, and then protruding a portion of the main body 61 of the balloon 60 disposed in the lumen 10a of the first shaft 10 and the lumen 20a of the tip member 20 from the first shaft 10. By expanding the balloon 60 while leaving a portion of the main body 61 protruding from the first shaft 10, it becomes easy to adjust the length of the main body 61 expanding outside the first shaft 10 to the length of the lesion. When a guidewire 1 is used, the guidewire 1 is placed in a body cavity, and then the distal end of the first shaft 10 is inserted to the lesion.

[0039] 7 , the first shaft 10 preferably has a protrusion 14 that protrudes inward in the radial direction y of the first shaft 10. With this configuration, when the balloon 60 is inflated with a portion of the main body 61 protruding from the first shaft 10, the protrusion 14 bites into the balloon 60, making it easier to suppress movement of the balloon 60 in the longitudinal direction x of the first shaft 10.

[0040] The first shaft 10 may have only one protrusion 14, but may also have a plurality of protrusions 14.

[0041] Each protrusion 14 may be elongated and extend in the longitudinal direction x of the first shaft 10, but is preferably elongated and extend in the circumferential direction c of the first shaft 10. Each protrusion 14 may be elongated and extend spirally so as to wind around the second shaft 50. Each protrusion 14 may be columnar, polygonal pyramidal, polygonal truncated pyramidal, conical, truncated conical, or hemispherical, and multiple protrusions 14 having these shapes may be scattered.

[0042] The proximal end of the tip member 20 may be connected to the distal end of the first shaft 10. The proximal end 20e of the tip member 20 may be connected to the distal end 10d of the first shaft 10. The proximal end of the tip member 20 may be fixed to the distal end of the first shaft 10. The proximal end 20e of the tip member 20 may be fixed to the distal end 10d of the first shaft 10.

[0043] The tip member 20 may have a tapered portion whose outer diameter decreases toward the distal side when the balloon 60 is deflated, i.e., in its natural state. The tip member 20 may have a straight tube portion whose outer diameter is constant when the balloon 60 is deflated, i.e., in its natural state.

[0044] The tip member 20 may be made of a material including resin and metal.

[0045] As shown in Figures 1 to 9, the tip member 20 preferably has a fixing portion 22 in its proximal portion. The fixing portion 22 is preferably a portion whose inner diameter does not expand due to the expansion of the balloon 60. Furthermore, the fixing portion 22 preferably has a portion that is fixed to the first shaft 10. It is preferable that at least a portion of the fixing portion 22 is fixed to the first shaft 10 in the longitudinal direction x of the first shaft 10. That is, only a portion of the fixing portion 22 may be fixed to the first shaft 10 in the longitudinal direction x of the first shaft 10, or the entire fixing portion 22 may be fixed to the first shaft 10 in the longitudinal direction x of the first shaft 10. Since the inner diameter of the fixing portion 22 does not expand due to the expansion of the balloon 60, it is possible to make the tip member 20 less likely to come off the first shaft 10.

[0046] The inner diameter of the fixing portion 22 may be expandable by expanding the balloon 60, but in this case, it is preferable that the rate of change of the inner diameter at the distal end of the fixing portion 22 before and after the expansion of the balloon 60 is smaller than the rate of change of the inner diameter at the distal end of the spiral portion 21 before and after the expansion of the balloon 60.

[0047] It is preferable that the proximal end of the fixing portion 22 is fixed to the distal end of the first shaft 10. The proximal end of the fixing portion 22 may be fixed to the distal end 10d of the first shaft 10. The distal end of the first shaft 10 may be inserted into the inner cavity of the fixing portion 22, and the inner surface of the fixing portion 22 may be fixed to the outer surface 10c of the first shaft 10. The fixing portion 22 may be inserted into the inner cavity 10a of the first shaft 10, and the inner surface 10b of the first shaft 10 and the outer surface of the fixing portion 22 may be fixed to each other.

[0048] The length of the portion of the tip member 20 in the longitudinal direction x of the first shaft 10 whose inner diameter can be expanded by expanding the balloon 60 is preferably longer than the length of the portion of the tip member 20 in the longitudinal direction x of the first shaft 10 whose inner diameter does not expand by expanding the balloon 60. Because the length of the portion of the tip member 20 in the longitudinal direction x of the first shaft 10 whose inner diameter can be expanded by expanding the balloon 60 is relatively long, the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10 can be easily visualized.

[0049] The tip member 20 may be composed of multiple members or may be composed of a single member. For example, the tip member 20 may include a ring-shaped member and a spiral member, with the proximal portion of the spiral member disposed in the lumen of the ring-shaped member. Alternatively, the tip member 20 may include a ring-shaped member and a spiral member, with the ring-shaped member and the spiral member fixed in a state aligned in the longitudinal direction x of the first shaft 10. The tip member 20 may include a tubular member, with the spiral portion 21 and the fixing portion 22 formed by making a spiral cut from the distal end of the tubular member toward the proximal side. The tip member 20 may include a spiral member, with the distal portion of the spiral member functioning as a portion whose inner diameter can be expanded by inflation of the balloon 60, and the proximal portion of the spiral member functioning as the fixing portion 22.

[0050] The spiral portion 21 is preferably made of a material containing a shape memory alloy, but may also be made of a material containing, for example, stainless steel such as SUS304 or SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, aluminum, gold, silver, a Ni-Ti alloy, or a Co-Cr alloy.

[0051] The helical pitch of the helical portion 21 may be constant from the distal end to the proximal end of the helical portion 21, or may have a helical pitch of various lengths. As shown in Figures 2 and 5, when the balloon 60 is deflated, the helical pitch of the helical portion 21 preferably increases toward the distal side. With this configuration, the inner diameter of the distal portion of the helical portion 21 is more likely to expand upon expansion of the balloon 60, and the distal portion of the helical portion 21 is more likely to conform to the shape of the proximal end of the main body portion 61 expanding outside of the first shaft 10.

[0052] As shown in Figure 8, the spiral portion 21 preferably has a tapered shape at its distal end. More specifically, in a cross section perpendicular to the longitudinal direction x of the first shaft 10, the cross-sectional area of ​​the spiral portion 21 preferably decreases toward the distal side. This configuration tends to reduce the rigidity of the distal portion of the spiral portion 21. As a result, the inner diameter of the distal portion of the spiral portion 21 tends to expand due to expansion of the balloon 60, and the distal portion of the spiral portion 21 tends to conform to the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10.

[0053] 9, the tip member 2 may have a plurality of spiral portions 21. Furthermore, the tip member 20 may have a spiral section 210 having the spiral portions 21 in the longitudinal direction x of the first shaft 10.

[0054] As shown in FIG. 9 , the multiple spiral portions 21 may include a first spiral portion 211 and a second spiral portion 212 whose distal end is located proximal to the distal end of the first spiral portion 211. In FIG. 9 , the second spiral portion 212 is hatched to make the shape of each spiral portion 21 easier to understand. This configuration tends to reduce the rigidity of the distal portion 210 a of the spiral section 210. This makes it easier for the inner diameter of the distal portion 210 a of the spiral section 210 to expand upon expansion of the balloon 60, and the spiral portion 21 constituting the distal portion 210 a of the spiral section 210 to easily conform to the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10. Although not shown, a configuration in which the distal ends of the multiple spiral portions 21 are all located at the same position in the longitudinal direction x of the first shaft 10 is also acceptable.

[0055] The distal end of the spiral portion 21 preferably has a rounded edge, as shown in Fig. 2, or a spherical edge, as shown at the distal end of the first spiral portion 211 in Fig. 9. By performing such a process on the distal end of the spiral portion 21, it is possible to more easily prevent damage to a blood vessel when the distal end of the spiral portion 21 comes into contact with the blood vessel. Furthermore, as shown in Fig. 9, the spherical edge may be formed from a material containing a radiopaque substance, thereby constituting the radiopaque portion 25.

[0056] 9 , the number of spiral portions 21 present in the proximal portion 210b of the spiral section 210 is preferably greater than the number of spiral portions 21 present in the distal portion 210a of the spiral section 210. This configuration tends to reduce the rigidity of the distal portion 210a of the spiral section 210. As a result, the inner diameter of the distal portion 210a of the spiral section 210 is likely to expand upon expansion of the balloon 60, and the spiral portions 21 constituting the distal portion 210a of the spiral section 210 are likely to conform to the shape of the proximal end portion of the main body portion 61 expanding outside the first shaft 10. Note that the number of spiral portions 21 present in the proximal portion 210b of the spiral section 210 may be the same as the number of spiral portions 21 present in the distal portion 210a of the spiral section 210.

[0057] 4, the distal end member 20 may have an outer membrane 23 that is disposed outward of the spiral portion 21 in the radial direction y of the first shaft 10 and is made of a material that is less rigid than the material that makes up the spiral portion 21. The spiral portion 21 may be partially or entirely embedded in the outer membrane 23. This makes it possible to prevent tissue damage that would occur if the spiral portion 21 came into direct contact with the tissue.

[0058] The outer membrane 23 is preferably cylindrical, with the spiral portion 21 disposed in its lumen. The distal end of the spiral portion 21 is preferably located proximal to the distal end of the outer membrane 23. It is more preferable that the entire spiral portion 21 be disposed in the lumen of the cylindrical outer membrane 23.

[0059] The outer membrane 23 can be made of any of the materials exemplified below as materials that can be used to make the balloon 60 .

[0060] The radiopaque portion 25 can be made of a material containing a radiopaque substance, such as lead, barium, iodine, tungsten, gold, platinum, iridium, stainless steel, titanium, or a cobalt-chromium alloy. The entire radiopaque portion 25 may be made of a radiopaque substance alone. The radiopaque portion 25 may also be made of a combination of a radiopaque substance and another material.

[0061] The second shaft 50 can be configured to have an inner cavity extending in the longitudinal direction x of the first shaft 10. As can be seen from Figures 2 to 7, the inner cavity of the second shaft 50 can be used as a passage for inserting the guide wire 1 or the like.

[0062] 2 to 7, the second shaft 50 may have a second inner shaft 51 and a second outer shaft 52. The second outer shaft 52 has an inner lumen and is preferably disposed in the inner lumen 10a of the first shaft 10. The second inner shaft 51 has an inner lumen in which the guide wire 1 is disposed and is preferably disposed in the inner lumen of the second outer shaft 52.

[0063] The second outer shaft 52 is preferably connected to an indeflator that injects a fluid to be supplied inside the balloon 60 .

[0064] The first shaft 10 and the second shaft 50 are preferably flexible, which allows the first shaft 10 and the second shaft 50 to be easily deformed to conform to the shape of the body cavity. In addition, the first shaft 10 and the second shaft 50 are preferably elastic in order to maintain their shape.

[0065] The shape of the first shaft 10 and the second shaft 50 may be, for example, a hollow cylindrical shape, a hollow polygonal prism shape, or the like.

[0066] The first shaft 10 and the second shaft 50 can be, for example, a hollow body formed by arranging one or more wires in a predetermined pattern; a hollow body with a resin coating on at least one of the inner and outer surfaces; a resin tube; or a combination of these, for example, a combination of these connected in the longitudinal direction. Examples of hollow bodies with 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 first shaft 10 and the second shaft 50 are resin tubes, the first shaft 10 and the second shaft 50 can be composed of a single layer or multiple layers. A portion of the first shaft 10 and the second shaft 50 in the longitudinal direction x or circumferential direction c of the first shaft 10 may be composed of a single layer, and the other portion may be composed of multiple layers.

[0067] The first shaft 10 and the second shaft 50 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 materials may be used alone or in combination of two or more. The first shaft 10 and the second shaft 50 may be made of the same material, or may be made of different materials.

[0068] The outer diameter of the first shaft 10 can be, for example, 1.0 mm or more, 1.1 mm or more, 1.2 mm or more, etc. The outer diameter of the first shaft 10 can also be, for example, 5.0 mm or less, 4.0 mm or less, 3.0 mm or less, etc., but is preferably 2.0 mm or less.

[0069] The inner diameter of the first shaft 10 can be, for example, 4.0 mm or less, 3.8 mm or less, 3.5 mm or less, etc. The inner diameter of the first shaft 10 can be, for example, 0.4 mm or more, 0.5 mm or more, 0.6 mm or more, etc., but is preferably 0.8 mm or more, and more preferably 1.2 mm or more. The inner diameter of the first shaft 10 is also preferably large enough to allow the second shaft 50 to pass through.

[0070] The balloon 60 is preferably made of a resin. Examples of resins that make up the balloon 60 include polyamide resin, polyester resin, polyurethane resin, polyolefin resin, vinyl chloride resin, silicone resin, and natural rubber. These may be used alone or in combination of two or more. Among these, polyamide resin, polyester resin, and polyurethane resin are preferred. From the viewpoint of thinning and flexibility of the balloon 60, an elastomer resin can be used.

[0071] The balloon 60 may have a distal sleeve portion 64 secured to the second inner shaft 51 and a proximal sleeve portion 65 secured to the second outer shaft 52 .

[0072] 3, 4, 6, and 7, when the balloon 60 is inflated, the main body 61 preferably has a portion 62 protruding from the first shaft 10 and a portion 63 located in the lumen 10a of the first shaft 10. When the balloon 60 is inflated, the portion 62 of the main body 61 protruding from the first shaft 10 preferably has a straight tube portion 62b, a distal tapered portion 62a located distal to the straight tube portion 62b, and a proximal tapered portion 62c located proximal to the straight tube portion 62b. The above-described configuration of the balloon 60 makes it easier for the straight tube portion 62b to come into contact with the lesion.

[0073] 3, it is preferable that the spiral portion 21 has an abutment portion 24 that abuts against the straight tube portion 62b when the balloon 60 is inflated. This makes it easier to visualize the proximal end of the straight tube portion 62b, which is likely to abut against the lesion.

[0074] The contact portion 24 is preferably arranged so as to be parallel to the longitudinal direction of the balloon 60, the longitudinal direction x of the first shaft 10, the longitudinal direction of the second shaft 50, etc. Note that "parallel" as used here includes strict parallelism ±10°.

[0075] When the balloon 60 is deflated, the balloon 60 has multiple blades 66, which are wound around the second shaft 50 in the circumferential direction of the second shaft 50. It is preferable that the spiral winding direction of the helical portion 21 and the spiral winding direction of the blades 66 are the same in the circumferential direction of the second shaft 50. In FIG. 8 , the spiral winding direction of the helical portion 21 coincides with the direction indicated by arrow A. In FIG. 10 , the spiral winding direction of the blades 66 coincides with the direction indicated by arrow B. This configuration facilitates smooth expansion of the inner diameter of the helical portion 21 when the balloon 60 is inflated. It is also acceptable for the spiral winding direction of the helical portion 21 and the spiral winding direction of the blades 66 to be opposite to each other.

[0076] 5 and 6 , it is preferable that the inner diameter of a portion of the first shaft 10 when the balloon 60 is inflated is larger than the inner diameter of the portion of the first shaft 10 when the balloon 60 is deflated, and the inner diameter of the fixing part 22 when the balloon 60 is inflated is smaller than the inner diameter of the portion of the first shaft 10 when the balloon 60 is inflated. This configuration makes it easier to suppress movement of the balloon 60 in the longitudinal direction x of the first shaft 10 when the balloon 60 is inflated with a portion of the main body part 61 protruding from the first shaft 10. For example, this can be implemented by having the first shaft 10 have an outer layer 15 and an inner layer 16 located inward of the outer layer 15 in the radial direction y of the first shaft 10, and the inner layer 16 being made of a material with a lower hardness than the outer layer 15. The hardness can be measured by measuring the repulsive force during compression, measuring the elastic modulus using a scanning probe microscope (SPM), measuring Rockwell hardness, measuring Shore hardness, etc., but it is preferably measured by measuring Shore hardness.

[0077] The length from the distal end to the proximal end of the catheter 100 can be, for example, 200 mm or more, 250 mm or more, 300 mm or more, etc. The length from the distal end to the proximal end of the catheter 100 can be, for example, 2500 mm or less, 2450 mm or less, 2400 mm or less, etc.

[0078] 1 , a hub 70 may be connected to the proximal portion of the first shaft 10. The first shaft 10 and the hub 70 may be fixed together. For example, the first shaft 10 and the hub 70 can be fixed together by bonding with an adhesive, welding, screws, or the like.

[0079] FIG. 1 discloses an embodiment in which a guidewire port 13 is formed midway from the distal end to the proximal end of the first shaft 10. The guidewire port 13 is in communication with the lumen 10a of the first shaft 10. FIG. 1 illustrates a so-called rapid exchange catheter 100. The first shaft 10 may have a first distal shaft portion 11 and a first proximal shaft portion 12 located proximally of the first distal shaft portion 11. The first distal shaft portion 11 and the first proximal shaft portion 12 may be separate members, with the proximal end of the member constituting the first distal shaft portion 11 connected to the distal end of the member constituting the first proximal shaft portion 12. Alternatively, the first distal shaft portion 11 and the first proximal shaft portion 12 may be formed from a single member.

[0080] Although not shown, the catheter 100 may be of a so-called over-the-wire type in which a lumen 10a is formed from the distal end to the proximal end of the first shaft 10. When the catheter 100 is of the over-the-wire type, it is preferable that the lumen 10a of the first shaft 10 extend in the longitudinal direction x of the catheter 100 to a position where the hub 70 is located.

[0081] The outer surface 10c of the first shaft 10 may be coated. As shown in Fig. 1, when the catheter 100 is of a rapid exchange type, the outer surface of at least one of the first distal shaft portion 11 and the first proximal shaft portion 12 may be coated, or the outer surfaces of both the first distal shaft portion 11 and the first proximal shaft portion 12 may be coated. When the catheter 100 is of an over-the-wire type, only a portion or the entire outer surface 10c of the first shaft 10 may be coated.

[0082] The coating applied to the outer surface 10c of the first shaft 10 can be a hydrophilic coating or a hydrophobic coating depending on the purpose. The coating can be applied by immersing the first shaft 10 in a hydrophilic or hydrophobic coating agent, by applying a hydrophilic or hydrophobic coating agent to the outer surface 10c of the first shaft 10, or by covering the outer surface 10c of the first shaft 10 with a hydrophilic or hydrophobic coating agent. Drugs or additives may be added to the coating agent.

[0083] 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.

[0084] 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.

[0085] (Embodiment 2)

[0086] A catheter according to one embodiment of the present invention comprises: a first shaft having a longitudinal direction and a radial direction and an inner lumen extending in the longitudinal direction; a tip member connected to the distal end of the first shaft, having an inner lumen communicating with the inner lumen of the first shaft, and having a braided section including a braided portion having an X-ray opaque portion in the longitudinal direction of the first shaft; a second shaft disposed in the lumen of the first shaft and the inner lumen of the tip member and moving in the longitudinal direction of the first shaft relative to the first shaft; and a balloon disposed in the distal portion of the second shaft, having a main body portion that expands and contracts in the radial direction of the first shaft, and the length of protrusion of the main body portion from the first shaft can be adjusted depending on the length of the lesion in the patient; and the catheter is characterized in that at least a portion of the braided section is disposed distal to the distal end of the first shaft, and the inner diameter of the braided section can be expanded by expanding the balloon.

[0087] The overall configuration of a catheter 100 according to an embodiment of the present invention will be described with reference to Figures 11 to 19. The figures show the catheter 100 including a first shaft 10, a tip member 20, a second shaft 50, and a balloon 60. The first shaft 10 has a longitudinal direction x, a radial direction y, and a circumferential direction c.

[0088] Members and parts of the catheter 100 other than the first shaft 10 also have longitudinal, radial, and circumferential directions. The longitudinal, radial, and circumferential directions of members and parts of the catheter 100 other than the first shaft 10 may or may not match the longitudinal direction x, radial direction y, and circumferential direction c of the first shaft 10. For ease of understanding, this specification shows an embodiment in which the longitudinal, radial, and circumferential directions of all members and parts match the longitudinal direction x, radial direction y, and circumferential direction c of the first shaft 10, respectively.

[0089] In this specification, the proximal side refers to the direction toward the user's hand in the longitudinal direction x of the first shaft 10, and the distal side refers to the opposite side of the proximal side, i.e., the direction toward the treatment target. Furthermore, when each member or part is divided into two equal halves in the longitudinal direction x of the first shaft 10, the distal portion of each member or part is referred to as the distal part of each member or part, and the proximal portion of each member or part is referred to as the proximal portion of each member or part. The distal end of each member or part is the end located most distally of each member or part. The proximal end of each member or part is the end located most proximal of each member 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.

[0090] FIG. 11 is a side view of a catheter according to an embodiment of the present invention. FIG. 12 is an enlarged cross-sectional view (partial side view) of the distal portion of the catheter shown in FIG. 11. FIG. 13 is a cross-sectional view (partial side view) of the catheter shown in FIG. 12, showing a state in which a portion of the main body portion is expanded outside the first shaft. FIG. 14 is a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 13. FIG. 15 is a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 12. FIG. 16 is a cross-sectional view (partial side view) of the catheter shown in FIG. 15, showing a state in which a portion of the main body portion is expanded outside the first shaft. FIG. 17 is a cross-sectional view (partial side view) of a modified example of the catheter shown in FIG. 13. More specifically, FIGS. 12 to 17 show cross sections passing through the central axis of the first shaft and parallel to the longitudinal direction of the first shaft. FIGS. 18 and 19 are side views showing modified examples of the tip member.

[0091] As shown in FIGS. 11 to 17, the catheter 100 includes a first shaft 10, a tip member 20, a second shaft 50, and a balloon 60.

[0092] 12 to 17, the first shaft 10 has a longitudinal direction x and a radial direction y, and has an inner lumen 10a extending in the longitudinal direction x. The first shaft 10 may have an inner surface 10b facing the inner lumen 10a and an outer surface 10c facing the exterior of the first shaft 10. The first shaft 10 also preferably has a distal end 10d and a proximal end.

[0093] 11 to 19, the tip member 20 is connected to the distal end of the first shaft 10 and has a lumen 20a that communicates with the lumen 10a of the first shaft 10. The tip member 20 may have an inner surface 20b that faces the lumen 20a and an outer surface 20c that faces the exterior of the tip member 20. The lumen 20a of the tip member 20 preferably extends in the longitudinal direction x of the first shaft 10. The tip member 20 also preferably has a distal end 20d and a proximal end 20e.

[0094] The distal end member 20 has a braided section 260. The braided section 260 is a section of the distal end member 20, and is a section that has a braided portion 26 in the longitudinal direction x of the first shaft 10. The braided portion 26 has an X-ray opaque portion 25.

[0095] As shown in Fig. 18, only a portion of the braided portion 26 may be formed from a material containing a radiopaque substance to form the radiopaque portion 25. As shown in Fig. 12, the entire braided portion 26 may be formed from a material containing a radiopaque substance to form the radiopaque portion 25.

[0096] In the braided section 260, the entirety of the first shaft 10 in the circumferential direction c may be formed by the braided portion 26. In the braided section 260, only a portion of the first shaft 10 in the circumferential direction c may be formed by the braided portion 26.

[0097] As shown in FIGS. 12 to 17, the second shaft 50 is disposed in the lumen 10a of the first shaft 10 and the lumen 20a of the tip member 20, and moves relative to the first shaft 10 in the longitudinal direction x of the first shaft 10.

[0098] 12 to 17, the balloon 60 is disposed at the distal portion of the second shaft 50 and has a main body 61 that expands and contracts in the radial direction y of the first shaft 10, and the length of the main body 61 protruding from the first shaft 10 can be adjusted depending on the length of the lesion in the patient. More specifically, it is preferable that the length of the main body 61 protruding from the first shaft 10 can be adjusted by moving the second shaft 50 relative to the first shaft 10 in the longitudinal direction x of the first shaft 10.

[0099] 12 to 17 , at least a portion of the braided section 260 is disposed distal to the distal end 10d of the first shaft 10. The entire braided section 260 may be disposed distal to the distal end 10d of the first shaft 10. Although not shown, only a portion of the braided section 260 may be disposed distal to the distal end 10d of the first shaft 10, with the remaining portion of the braided section 260 being disposed proximal to the distal end 10d of the first shaft 10.

[0100] As shown in Figures 12 to 17, the inner diameter of the braided section 260 can be expanded by expanding the balloon 60. Figures 12 and 15 show a state in which the balloon 60 is deflated. Figures 13, 14, 16, and 17 show a state in which the balloon 60 is expanded and the inner diameter of the braided section 260 is expanded. The inner diameter of only a portion of the braided section 260 may be expanded, or the inner diameter of the entire braided section 260 may be expanded.

[0101] 12 to 17 , the expansion of the balloon 60 expands the inner diameter of the braided section 260, which allows the braided section 260 to more easily conform to the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10. Because the braided portion 26 of the braided section 260 has an X-ray opaque portion 25, the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10 can be easily visualized under X-ray fluoroscopy. This makes it easy to adjust the length of the main body portion 61 expanding outside the first shaft 10 to the length of the lesion, and to appropriately position the main body portion 61 expanding outside the first shaft 10 at the lesion. This makes it easier to prevent damage to normal tissue caused by treatment being performed on areas other than the lesion.

[0102] The catheter 100 can be used, for example, by inserting the distal end of the first shaft 10 to the lesion, and then protruding a portion of the main body 61 of the balloon 60 disposed in the lumen 10a of the first shaft 10 and the lumen 20a of the tip member 20 from the first shaft 10. By expanding the balloon 60 while leaving a portion of the main body 61 protruding from the first shaft 10, it becomes easy to adjust the length of the main body 61 expanding outside the first shaft 10 to the length of the lesion. When a guidewire 1 is used, the guidewire 1 is placed in a body cavity, and then the distal end of the first shaft 10 is inserted to the lesion.

[0103] 17 , the first shaft 10 preferably has a protrusion 14 that protrudes inward in the radial direction y of the first shaft 10. With this configuration, when the balloon 60 is inflated with a portion of the main body 61 protruding from the first shaft 10, the protrusion 14 bites into the balloon 60, making it easier to suppress movement of the balloon 60 in the longitudinal direction x of the first shaft 10.

[0104] The first shaft 10 may have only one protrusion 14, but may also have a plurality of protrusions 14.

[0105] Each protrusion 14 may be elongated and extend in the longitudinal direction x of the first shaft 10, but is preferably elongated and extend in the circumferential direction c of the first shaft 10. Each protrusion 14 may be elongated and extend spirally so as to wind around the second shaft 50. Each protrusion 14 may be columnar, polygonal pyramidal, polygonal truncated pyramidal, conical, truncated conical, or hemispherical, and multiple protrusions 14 having these shapes may be scattered.

[0106] The proximal end of the tip member 20 may be connected to the distal end of the first shaft 10. The proximal end 20e of the tip member 20 may be connected to the distal end 10d of the first shaft 10. The proximal end of the tip member 20 may be fixed to the distal end of the first shaft 10. The proximal end 20e of the tip member 20 may be fixed to the distal end 10d of the first shaft 10.

[0107] The tip member 20 may have a tapered portion whose outer diameter decreases toward the distal side when the balloon 60 is deflated, i.e., in its natural state. The tip member 20 may have a straight tube portion whose outer diameter is constant when the balloon 60 is deflated, i.e., in its natural state.

[0108] The tip member 20 may be made of a material including resin and metal.

[0109] As shown in Figures 11 to 19, the tip member 20 preferably has a fixing portion 22 in its proximal portion. The fixing portion 22 is preferably a portion whose inner diameter does not expand due to the expansion of the balloon 60. Furthermore, the fixing portion 22 preferably has a portion that is fixed to the first shaft 10. It is preferable that at least a portion of the fixing portion 22 is fixed to the first shaft 10 in the longitudinal direction x of the first shaft 10. That is, only a portion of the fixing portion 22 may be fixed to the first shaft 10 in the longitudinal direction x of the first shaft 10, or the entire fixing portion 22 may be fixed to the first shaft 10 in the longitudinal direction x of the first shaft 10. Since the inner diameter of the fixing portion 22 does not expand due to the expansion of the balloon 60, it is possible to make the tip member 20 less likely to come off the first shaft 10.

[0110] The inner diameter of the fixing portion 22 may be expandable by expanding the balloon 60, but in this case, it is preferable that the rate of change in the inner diameter at the distal end of the fixing portion 22 before and after the expansion of the balloon 60 is smaller than the rate of change in the inner diameter at the distal end of the braided section 260 before and after the expansion of the balloon 60.

[0111] It is preferable that the proximal end of the fixing portion 22 is fixed to the distal end of the first shaft 10. The proximal end of the fixing portion 22 may be fixed to the distal end 10d of the first shaft 10. The distal end of the first shaft 10 may be inserted into the inner cavity of the fixing portion 22, and the inner surface of the fixing portion 22 may be fixed to the outer surface 10c of the first shaft 10. The fixing portion 22 may be inserted into the inner cavity 10a of the first shaft 10, and the inner surface 10b of the first shaft 10 and the outer surface of the fixing portion 22 may be fixed to each other.

[0112] The length of the portion of the tip member 20 in the longitudinal direction x of the first shaft 10 whose inner diameter can be expanded by expanding the balloon 60 is preferably longer than the length of the portion of the tip member 20 in the longitudinal direction x of the first shaft 10 whose inner diameter does not expand by expanding the balloon 60. Because the length of the portion of the tip member 20 in the longitudinal direction x of the first shaft 10 whose inner diameter can be expanded by expanding the balloon 60 is relatively long, the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10 can be easily visualized.

[0113] 12 and 13 , the distal end member 20 may be composed of a braided portion 26 having a plurality of wires 27, and a ring-shaped member 29 constituting the fixing portion 22. The proximal end of the wires 27 may be fixed to the distal end of the ring-shaped member 29. Although not shown, a proximal portion of the braided portion 26 may be disposed in the inner cavity of the ring-shaped member 29. In this case, the ring-shaped member 29 and the braided portion 26 disposed in the inner cavity of the ring-shaped member 29 correspond to the fixing portion 22.

[0114] As the material for forming the ring-shaped member 29, the materials exemplified as materials for forming the first shaft 10 and the second shaft 50 described later can be used.

[0115] The braided portion 26 is preferably made of a material containing a shape memory alloy. The braided portion 26 may be made of a material containing, for example, stainless steel such as SUS304 or SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, aluminum, gold, silver, a Ni-Ti alloy, or a Co-Cr alloy.

[0116] 12 and 15 , when the balloon 60 is deflated, the braid pitch of the braided portion 26 preferably increases toward the distal side. This configuration tends to reduce the rigidity of the distal portion of the braided portion 26. Therefore, the inner diameter of the distal portion of the braided section 260 tends to expand due to the expansion of the balloon 60, and the distal portion of the braided section 260 tends to conform to the shape of the proximal end portion of the main body portion 61 expanding outside the first shaft 10.

[0117] 18 , the wire 27 preferably has a tapered shape at its distal portion. More specifically, in a cross section perpendicular to the longitudinal direction x of the first shaft 10, the cross-sectional area of ​​the wire 27 preferably decreases toward the distal side. This configuration tends to reduce the rigidity of the distal portion of the wire 27. As a result, the inner diameter of the distal portion of the braided section 260 tends to expand due to expansion of the balloon 60, and the distal portion of the braided section 260 tends to conform to the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10.

[0118] The wire 27 may have a first end and a second end in the longitudinal direction. Both the first end and the second end of the wire 27 are preferably located proximal to the distal end of the wire 27. The first end and the second end of the wire 27 are preferably located proximal to the distal end 20d of the tip member 20. The wire 27 may be curved so as to be convex toward the distal side. The above-described configuration makes it easier to prevent damage to a blood vessel when the wire 27 comes into contact with the blood vessel.

[0119] The position of the first end of the wire 27 may coincide with the position of the distal end of the wire 27, and the position of the second end of the wire 27 may coincide with the position of the proximal end of the wire 27. With this configuration, the inner diameter of the distal portion of the braided section 260 is more likely to expand upon expansion of the balloon 60, making it easier for the distal portion of the braided section 260 to conform to the shape of the proximal end of the main body 61 expanding outside the first shaft 10. Furthermore, when using the above configuration, it is preferable that the first end (the distal end) of the wire 27 has a rounded edge by being rounded or by being spherically processed as shown in the wire 27 in FIG. 18 . Processing the first end (the distal end) of the wire 27 in this manner can more easily prevent damage to a blood vessel when the wire 27 comes into contact with the blood vessel. Furthermore, as shown in FIG. 18 , the spherically processed portion of the first end (the distal end) of the wire 27 may be formed of a material containing a radiopaque substance, thereby forming the radiopaque portion 25.

[0120] 19 , the plurality of wires 27 may include a first wire 271 and a second wire 272 whose distal end is located proximal to the distal end of the first wire 271. This configuration tends to reduce the rigidity of the distal portion of the braided section 260. This makes it easier for the inner diameter of the distal portion of the braided section 260 to expand upon expansion of the balloon 60, and the distal portion of the braided section 260 to more easily conform to the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10. Note that an embodiment in which the distal ends of the plurality of wires 27 are all positioned at the same position in the longitudinal direction x of the first shaft 10 is also acceptable.

[0121] 19 , the number of wires 27 present in the proximal portion 26b of the braided portion 26 is preferably greater than the number of wires 27 present in the distal portion 26a of the braided portion 26. This configuration tends to reduce the rigidity of the distal portion of the braided section 260. As a result, the inner diameter of the distal portion of the braided section 260 is more likely to expand upon expansion of the balloon 60, and the distal portion of the braided section 260 is more likely to conform to the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10. Note that the number of wires 27 present in the proximal portion 26b of the braided portion 26 may be the same as the number of wires 27 present in the distal portion 26a of the braided portion 26.

[0122] 14 , the distal end member 20 may have an outer membrane 23 that is disposed outward of the braided portion 26 in the radial direction y of the first shaft 10 and is made of a material that is less rigid than the material that makes up the braided portion 26. The braided portion 26 may be partially or entirely embedded in the outer membrane 23. This makes it possible to prevent tissue damage that would occur if the braided portion 26 came into direct contact with the tissue.

[0123] The outer membrane 23 is preferably tubular, with the braided portion 26 disposed in its lumen. The distal end of the braided portion 26 is preferably located proximal to the distal end of the outer membrane 23. It is more preferable that the entire braided portion 26 be disposed in the lumen of the tubular outer membrane 23.

[0124] The outer membrane 23 can be made of any of the materials exemplified below as materials that can be used to make the balloon 60 .

[0125] The radiopaque portion 25 can be made of a material containing a radiopaque substance, such as lead, barium, iodine, tungsten, gold, platinum, iridium, stainless steel, titanium, or a cobalt-chromium alloy. The entire radiopaque portion 25 may be made of a radiopaque substance alone. The radiopaque portion 25 may also be made of a combination of a radiopaque substance and another material.

[0126] The second shaft 50 can be configured to have an inner cavity extending in the longitudinal direction x of the first shaft 10. As can be seen from Figures 12 to 17, the inner cavity of the second shaft 50 can be used as a passage for inserting the guide wire 1 or the like.

[0127] 12 to 17, the second shaft 50 may have a second inner shaft 51 and a second outer shaft 52. The second outer shaft 52 has an inner lumen and is preferably disposed in the inner lumen 10a of the first shaft 10. The second inner shaft 51 has an inner lumen in which the guide wire 1 is disposed and is preferably disposed in the inner lumen of the second outer shaft 52.

[0128] The second outer shaft 52 is preferably connected to an indeflator that injects a fluid to be supplied inside the balloon 60 .

[0129] The first shaft 10 and the second shaft 50 are preferably flexible, which allows the first shaft 10 and the second shaft 50 to be easily deformed to conform to the shape of the body cavity. In addition, the first shaft 10 and the second shaft 50 are preferably elastic in order to maintain their shape.

[0130] The shape of the first shaft 10 and the second shaft 50 may be, for example, a hollow cylindrical shape, a hollow polygonal prism shape, or the like.

[0131] The first shaft 10 and the second shaft 50 can be, for example, a hollow body formed by arranging one or more wires in a predetermined pattern; a hollow body with a resin coating on at least one of the inner and outer surfaces; a resin tube; or a combination of these, for example, a combination of these connected in the longitudinal direction. Examples of hollow bodies with 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 first shaft 10 and the second shaft 50 are resin tubes, the first shaft 10 and the second shaft 50 can be composed of a single layer or multiple layers. A portion of the first shaft 10 and the second shaft 50 in the longitudinal direction x or circumferential direction c of the first shaft 10 may be composed of a single layer, and the other portion may be composed of multiple layers.

[0132] The first shaft 10 and the second shaft 50 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 materials may be used alone or in combination of two or more. The first shaft 10 and the second shaft 50 may be made of the same material, or may be made of different materials.

[0133] The outer diameter of the first shaft 10 can be, for example, 1.0 mm or more, 1.1 mm or more, 1.2 mm or more, etc. The outer diameter of the first shaft 10 can also be, for example, 5.0 mm or less, 4.0 mm or less, 3.0 mm or less, etc., but is preferably 2.0 mm or less.

[0134] The inner diameter of the first shaft 10 can be, for example, 4.0 mm or less, 3.8 mm or less, 3.5 mm or less, etc. The inner diameter of the first shaft 10 can be, for example, 0.4 mm or more, 0.5 mm or more, 0.6 mm or more, etc., but is preferably 0.8 mm or more, and more preferably 1.2 mm or more. The inner diameter of the first shaft 10 is also preferably large enough to allow the second shaft 50 to pass through.

[0135] The balloon 60 is preferably made of a resin. Examples of resins that make up the balloon 60 include polyamide resin, polyester resin, polyurethane resin, polyolefin resin, vinyl chloride resin, silicone resin, and natural rubber. These may be used alone or in combination of two or more. Among these, polyamide resin, polyester resin, and polyurethane resin are preferred. From the viewpoint of thinning and flexibility of the balloon 60, an elastomer resin can be used.

[0136] The balloon 60 may have a distal sleeve portion 64 secured to the second inner shaft 51 and a proximal sleeve portion 65 secured to the second outer shaft 52 .

[0137] 13, 14, 16, and 17, when the balloon 60 is inflated, the main body 61 preferably has a portion 62 protruding from the first shaft 10 and a portion 63 located in the lumen 10a of the first shaft 10. When the balloon 60 is inflated, the portion 62 of the main body 61 protruding from the first shaft 10 preferably has a straight tube portion 62b, a distal tapered portion 62a located distal to the straight tube portion 62b, and a proximal tapered portion 62c located proximal to the straight tube portion 62b. The above-described configuration of the balloon 60 makes it easier for the straight tube portion 62b to come into contact with the lesion.

[0138] 13, it is preferable that the braided section 260 has an abutting portion 24 that abuts against the straight tube portion 62b when the balloon 60 is inflated. This makes it easier to visualize the proximal end of the straight tube portion 62b, which is likely to abut against the lesion.

[0139] The contact portion 24 is preferably arranged so as to be parallel to the longitudinal direction of the balloon 60, the longitudinal direction x of the first shaft 10, the longitudinal direction of the second shaft 50, etc. Note that "parallel" as used here includes strict parallelism ±10°.

[0140] 15 and 16 , it is preferable that the inner diameter of a portion of the first shaft 10 when the balloon 60 is inflated is larger than the inner diameter of the portion of the first shaft 10 when the balloon 60 is deflated, and that the inner diameter of the fixing part 21 when the balloon 60 is inflated is smaller than the inner diameter of the portion of the first shaft 10 when the balloon 60 is inflated. This configuration makes it easier to suppress movement of the balloon 60 in the longitudinal direction x of the first shaft 10 when the balloon 60 is inflated with a portion of the main body part 61 protruding from the first shaft 10. For example, this can be implemented by having the first shaft 10 have an outer layer 15 and an inner layer 16 located inward of the outer layer 15 in the radial direction y of the first shaft 10, and the inner layer 16 being made of a material with a lower hardness than the outer layer 15. The hardness can be measured by measuring the repulsive force during compression, measuring the elastic modulus using a scanning probe microscope (SPM), measuring Rockwell hardness, measuring Shore hardness, etc., but it is preferably measured by measuring Shore hardness.

[0141] The length from the distal end to the proximal end of the catheter 100 can be, for example, 200 mm or more, 250 mm or more, 300 mm or more, etc. The length from the distal end to the proximal end of the catheter 100 can be, for example, 2500 mm or less, 2450 mm or less, 2400 mm or less, etc.

[0142] 11 , a hub 70 may be connected to the proximal portion of the first shaft 10. The first shaft 10 and the hub 70 may be fixed together. For example, the first shaft 10 and the hub 70 can be fixed together by bonding with an adhesive, welding, screws, or the like.

[0143] FIG. 11 discloses an embodiment in which a guidewire port 13 is formed midway from the distal end to the proximal end of the first shaft 10. The guidewire port 13 is in communication with the lumen 10a of the first shaft 10. FIG. 11 shows a so-called rapid exchange catheter 100. The first shaft 10 may have a first distal shaft portion 11 and a first proximal shaft portion 12 located proximally of the first distal shaft portion 11. The first distal shaft portion 11 and the first proximal shaft portion 12 may be separate members, with the proximal end of the member constituting the first distal shaft portion 11 connected to the distal end of the member constituting the first proximal shaft portion 12. Alternatively, the first distal shaft portion 11 and the first proximal shaft portion 12 may be formed from a single member.

[0144] Although not shown, the catheter 100 may be of a so-called over-the-wire type in which a lumen 10a is formed from the distal end to the proximal end of the first shaft 10. When the catheter 100 is of the over-the-wire type, it is preferable that the lumen 10a of the first shaft 10 extend in the longitudinal direction x of the catheter 100 to a position where the hub 70 is located.

[0145] The outer surface 10c of the first shaft 10 may be coated. As shown in Fig. 11, when the catheter 100 is of a rapid exchange type, the outer surface of at least one of the first distal shaft section 11 and the first proximal shaft section 12 may be coated, or the outer surfaces of both the first distal shaft section 11 and the first proximal shaft section 12 may be coated. When the catheter 100 is of an over-the-wire type, only a portion or the entire outer surface 10c of the first shaft 10 may be coated.

[0146] The coating applied to the outer surface 10c of the first shaft 10 can be a hydrophilic coating or a hydrophobic coating depending on the purpose. The coating can be applied by immersing the first shaft 10 in a hydrophilic or hydrophobic coating agent, by applying a hydrophilic or hydrophobic coating agent to the outer surface 10c of the first shaft 10, or by covering the outer surface 10c of the first shaft 10 with a hydrophilic or hydrophobic coating agent. Drugs or additives may be added to the coating agent.

[0147] 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.

[0148] 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.

[0149] (Embodiment 3)

[0150] A catheter according to one embodiment of the present invention comprises: a first shaft having a longitudinal direction and a radial direction and a lumen extending in the longitudinal direction; a tip member connected to the distal end of the first shaft, having an inner lumen communicating with the lumen of the first shaft, and having a mesh section with a mesh portion having an X-ray opaque portion in the longitudinal direction of the first shaft; a second shaft disposed in the lumen of the first shaft and the lumen of the tip member and moving in the longitudinal direction of the first shaft relative to the first shaft; and a balloon disposed in the distal portion of the second shaft, having a main body portion that expands and contracts in the radial direction of the first shaft, and the length of the main body portion protruding from the first shaft can be adjusted depending on the length of the lesion in the patient. The gist of the catheter is that the mesh section has a plurality of openings that connect the outside of the tip member with the lumen of the tip member in the radial direction of the first shaft, and at least a portion of the mesh section is disposed distal to the distal end of the first shaft, and the inner diameter of the mesh section can be expanded by expanding the balloon.

[0151] The overall configuration of a catheter 100 according to an embodiment of the present invention will be described with reference to Figures 20 to 27. The figures show the catheter 100 including a first shaft 10, a tip member 20, a second shaft 50, and a balloon 60. The first shaft 10 has a longitudinal direction x, a radial direction y, and a circumferential direction c.

[0152] Members and parts of the catheter 100 other than the first shaft 10 also have longitudinal, radial, and circumferential directions. The longitudinal, radial, and circumferential directions of members and parts of the catheter 100 other than the first shaft 10 may or may not match the longitudinal direction x, radial direction y, and circumferential direction c of the first shaft 10. For ease of understanding, this specification shows an embodiment in which the longitudinal, radial, and circumferential directions of all members and parts match the longitudinal direction x, radial direction y, and circumferential direction c of the first shaft 10, respectively.

[0153] In this specification, the proximal side refers to the direction toward the user's hand in the longitudinal direction x of the first shaft 10, and the distal side refers to the opposite side of the proximal side, i.e., the direction toward the treatment target. Furthermore, when each member or part is divided into two equal halves in the longitudinal direction x of the first shaft 10, the distal portion of each member or part is referred to as the distal part of each member or part, and the proximal portion of each member or part is referred to as the proximal portion of each member or part. The distal end of each member or part is the end located most distally of each member or part. The proximal end of each member or part is the end located most proximal of each member 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.

[0154] Fig. 20 is a side view of a catheter according to an embodiment of the present invention. Fig. 21 is an enlarged cross-sectional view (partial side view) of the distal portion of the catheter shown in Fig. 20. Fig. 22 is a cross-sectional view (partial side view) of the catheter shown in Fig. 21, showing a state in which a portion of the main body portion is expanded outside the first shaft. Fig. 23 is a cross-sectional view (partial side view) of a modified example of the catheter shown in Fig. 22. Fig. 24 is a cross-sectional view (partial side view) of a modified example of the catheter shown in Fig. 21. Fig. 25 is a cross-sectional view (partial side view) of the catheter shown in Fig. 24, showing a state in which a portion of the main body portion is expanded outside the first shaft. Fig. 26 is a cross-sectional view (partial side view) of a modified example of the catheter shown in Fig. 22. More specifically, Figs. 21 to 26 show cross sections passing through the central axis of the first shaft and parallel to the longitudinal direction of the first shaft. Fig. 27 is a side view of a modified example of a tip member.

[0155] As shown in FIGS. 20 to 26, the catheter 100 includes a first shaft 10, a tip member 20, a second shaft 50, and a balloon 60.

[0156] 21 to 26, the first shaft 10 has a longitudinal direction x and a radial direction y, and has an inner lumen 10a extending in the longitudinal direction x. The first shaft 10 may have an inner surface 10b facing the inner lumen 10a and an outer surface 10c facing the exterior of the first shaft 10. The first shaft 10 also preferably has a distal end 10d and a proximal end.

[0157] 20 to 27, the tip member 20 is connected to the distal end of the first shaft 10 and has a lumen 20a that communicates with the lumen 10a of the first shaft 10. The tip member 20 may have an inner surface 20b that faces the lumen 20a and an outer surface 20c that faces the exterior of the tip member 20. The lumen 20a of the tip member 20 preferably extends in the longitudinal direction x of the first shaft 10. The tip member 20 also preferably has a distal end 20d and a proximal end 20e.

[0158] The distal end member 20 has a mesh section 300. The mesh section 300 is a section of the distal end member 20, and is a section that includes a mesh portion 30 in the longitudinal direction x of the first shaft 10. The mesh portion 30 has an X-ray opaque portion 25.

[0159] As shown in Fig. 27, only a portion of the mesh portion 30 may be formed from a material containing a radiopaque substance to form the radiopaque portion 25. As shown in Fig. 21, the entire mesh portion 30 may be formed from a material containing a radiopaque substance to form the radiopaque portion 25.

[0160] In the mesh section 300, the entirety of the first shaft 10 in the circumferential direction c may be formed by the mesh portion 30. In the mesh section 300, only a portion of the first shaft 10 in the circumferential direction c may be formed by the mesh portion 30.

[0161] The mesh portion 30 has a plurality of openings 31 that connect the outside of the tip member 20 with the inner cavity 20 a of the tip member 20 in the radial direction y of the first shaft 10 .

[0162] As shown in FIGS. 21 to 26, the second shaft 50 is disposed in the lumen 10a of the first shaft 10 and the lumen 20a of the tip member 20, and moves relative to the first shaft 10 in the longitudinal direction x of the first shaft 10.

[0163] 21 to 26, the balloon 60 is disposed at the distal portion of the second shaft 50, has a main body portion 61 that expands and contracts in the radial direction y of the first shaft 10, and the length of the main body portion 61 protruding from the first shaft 10 can be adjusted depending on the length of the lesion in the patient. More specifically, it is preferable that the length of the main body portion 61 protruding from the first shaft 10 can be adjusted by moving the second shaft 50 relative to the first shaft 10 in the longitudinal direction x of the first shaft 10.

[0164] 21 to 26 , at least a portion of the braided section 300 is disposed distal to the distal end 10d of the first shaft 10. The entire braided section 300 may be disposed distal to the distal end 10d of the first shaft 10. Although not shown, only a portion of the braided section 300 may be disposed distal to the distal end 10d of the first shaft 10, with the remaining portion of the braided section 300 being disposed proximal to the distal end 10d of the first shaft 10.

[0165] As shown in Figures 21 to 26, the inner diameter of the reticulated section 300 can be expanded by expanding the balloon 60. Figures 21 and 24 show a state in which the balloon 60 is deflated. Figures 22, 23, 25, and 26 show a state in which the balloon 60 is expanded and the inner diameter of the reticulated section 300 is expanded. The inner diameter of only a portion of the reticulated section 300 may be expanded, or the inner diameter of the entire reticulated section 300 may be expanded.

[0166] 21 to 26 , the expansion of the balloon 60 expands the inner diameter of the mesh section 300, which allows the mesh section 300 to more easily conform to the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10. Because the mesh section 30 of the mesh section 300 has an X-ray opaque portion 25, the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10 can be easily visualized under X-ray fluoroscopy. This makes it easy to adjust the length of the main body portion 61 expanding outside the first shaft 10 to the length of the lesion, and to appropriately position the main body portion 61 expanding outside the first shaft 10 at the lesion. This makes it easier to prevent damage to normal tissue caused by treatment being performed on areas other than the lesion.

[0167] The catheter 100 can be used, for example, by inserting the distal end of the first shaft 10 to the lesion, and then protruding a portion of the main body 61 of the balloon 60 disposed in the lumen 10a of the first shaft 10 and the lumen 20a of the tip member 20 from the first shaft 10. By expanding the balloon 60 while leaving a portion of the main body 61 protruding from the first shaft 10, it becomes easy to adjust the length of the main body 61 expanding outside the first shaft 10 to the length of the lesion. When a guidewire 1 is used, the guidewire 1 is placed in a body cavity, and then the distal end of the first shaft 10 is inserted to the lesion.

[0168] 26 , the first shaft 10 preferably has a protrusion 14 that protrudes inward in the radial direction y of the first shaft 10. With this configuration, when the balloon 60 is inflated with a portion of the main body 61 protruding from the first shaft 10, the protrusion 14 bites into the balloon 60, making it easier to suppress movement of the balloon 60 in the longitudinal direction x of the first shaft 10.

[0169] The first shaft 10 may have only one protrusion 14, but may also have a plurality of protrusions 14.

[0170] Each protrusion 14 may be elongated and extend in the longitudinal direction x of the first shaft 10, but is preferably elongated and extend in the circumferential direction c of the first shaft 10. Each protrusion 14 may be elongated and extend spirally so as to wind around the second shaft 50. Each protrusion 14 may be columnar, polygonal pyramidal, polygonal truncated pyramidal, conical, truncated conical, or hemispherical, and multiple protrusions 14 having these shapes may be scattered.

[0171] The proximal end of the tip member 20 may be connected to the distal end of the first shaft 10. The proximal end 20e of the tip member 20 may be connected to the distal end 10d of the first shaft 10. The proximal end of the tip member 20 may be fixed to the distal end of the first shaft 10. The proximal end 20e of the tip member 20 may be fixed to the distal end 10d of the first shaft 10.

[0172] The tip member 20 may have a tapered portion whose outer diameter decreases toward the distal side when the balloon 60 is deflated, i.e., in its natural state. The tip member 20 may have a straight tube portion whose outer diameter is constant when the balloon 60 is deflated, i.e., in its natural state.

[0173] The tip member 20 may be made of a material including resin and metal.

[0174] As shown in Figures 20 to 27, the tip member 20 preferably has a fixing portion 22 in its proximal portion. The fixing portion 22 is preferably a portion whose inner diameter does not expand due to the expansion of the balloon 60. Furthermore, the fixing portion 22 preferably has a portion that is fixed to the first shaft 10. It is preferable that at least a portion of the fixing portion 22 is fixed to the first shaft 10 in the longitudinal direction x of the first shaft 10. That is, only a portion of the fixing portion 22 may be fixed to the first shaft 10 in the longitudinal direction x of the first shaft 10, or the entire fixing portion 22 may be fixed to the first shaft 10 in the longitudinal direction x of the first shaft 10. Since the inner diameter of the fixing portion 22 does not expand due to the expansion of the balloon 60, it is possible to make the tip member 20 less likely to come off the first shaft 10.

[0175] The inner diameter of the fixing portion 22 may be expandable by expanding the balloon 60, but in this case, it is preferable that the rate of change in the inner diameter at the distal end of the fixing portion 22 before and after the expansion of the balloon 60 is smaller than the rate of change in the inner diameter at the distal end of the mesh section 300 before and after the expansion of the balloon 60.

[0176] It is preferable that the proximal end of the fixing portion 22 is fixed to the distal end of the first shaft 10. The proximal end of the fixing portion 22 may be fixed to the distal end 10d of the first shaft 10. The distal end of the first shaft 10 may be inserted into the inner cavity of the fixing portion 22, and the inner surface of the fixing portion 22 may be fixed to the outer surface 10c of the first shaft 10. The fixing portion 22 may be inserted into the inner cavity 10a of the first shaft 10, and the inner surface 10b of the first shaft 10 and the outer surface of the fixing portion 22 may be fixed to each other.

[0177] The length of the portion of the tip member 20 in the longitudinal direction x of the first shaft 10 whose inner diameter can be expanded by expanding the balloon 60 is preferably longer than the length of the portion of the tip member 20 in the longitudinal direction x of the first shaft 10 whose inner diameter does not expand by expanding the balloon 60. Because the length of the portion of the tip member 20 in the longitudinal direction x of the first shaft 10 whose inner diameter can be expanded by expanding the balloon 60 is relatively long, the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10 can be easily visualized.

[0178] The distal end member 20 may be composed of multiple components or a single component. For example, the distal end member 20 may include a ring-shaped member and a mesh member, with the proximal portion of the mesh member disposed in the lumen of the ring-shaped member. Alternatively, the distal end member 20 may include a ring-shaped member and a mesh member, with the ring-shaped member and the mesh member fixed in a state aligned in the longitudinal direction x of the first shaft 10. The distal end member 20 may include a tubular member, with the mesh section 300 and the fixing portion 22 formed by providing openings in only a partial section of the tubular member in the longitudinal direction x. The distal end member 20 may include a mesh member, with the distal portion of the mesh member serving as the mesh section 300 and functioning as a portion whose inner diameter can be expanded by expanding the balloon 60, and the proximal portion of the mesh member functioning as the fixing portion 22.

[0179] The mesh portion 30 is preferably made of a material containing a shape memory alloy, but may also be made of a material containing, for example, stainless steel such as SUS304 or SUS316, platinum, nickel, cobalt, chromium, titanium, tungsten, aluminum, gold, silver, a Ni-Ti alloy, or a Co-Cr alloy.

[0180] 21 to 27, the mesh portion 30 may have linear portions 32 that form the mesh. The linear portions 32 are linear portions.

[0181] As shown in FIG. 27 , the mesh portion 30 includes a linear portion 32 connected to the proximal end of the radiopaque portion 25 and forming a mesh. The length of the radiopaque portion 25 in the radial direction 10 of the first shaft 10 is preferably longer than the length of the linear portion 32 in the radial direction y of the first shaft 10. In this embodiment, as shown in FIG. 27 , the radiopaque portion 25 is preferably spherical. The wire diameter of the linear portion 32 may be smaller than the diameter of the spherical radiopaque portion 25. This configuration makes it easier to visualize the position of the distal end of the mesh portion 30. The longest length of the radiopaque portion 25 in the radial direction 10 of the first shaft 10 is compared with the longest length of the linear portion 32 in the radial direction y of the first shaft 10. The linear portion 32 may also be made of a material containing a radiopaque substance, as described below, or may not contain a radiopaque substance.

[0182] Although not shown, the wire portion 32 preferably has a tapered shape at its distal end. More specifically, in a cross section perpendicular to the longitudinal direction x of the first shaft 10, the cross-sectional area of ​​the wire portion 32 preferably decreases toward the distal side. This configuration tends to reduce the rigidity of the distal portion 30a of the mesh portion 30. As a result, the inner diameter of the distal portion of the mesh section 300 tends to expand due to expansion of the balloon 60, and the distal portion of the mesh section 300 tends to conform to the shape of the proximal end of the main body portion 61 expanding outside the first shaft 10.

[0183] 21 and 24 , when the balloon 60 is deflated, the average area of ​​the openings 31 located in the distal portion 30a of the mesh portion 30 is preferably larger than the average area of ​​the openings 31 located in the proximal portion 30b of the mesh portion 30. This configuration tends to reduce the rigidity of the distal portion 30a of the mesh portion 30. As a result, the inner diameter of the distal portion of the mesh section 300 tends to expand when the balloon 60 is expanded, and the distal portion of the mesh section 300 tends to conform to the shape of the proximal end portion of the main body portion 61 expanding outside the first shaft 10.

[0184] The mesh portion 30 may be composed of a single member or multiple members. For example, the mesh portion 30 may have a tubular member, and the tubular member may be configured by forming multiple openings in the tubular member that connect the outside of the tubular member with the inner cavity of the tubular member in the radial direction of the tubular member. In this case, the openings formed in the tubular member are the openings 31 of the mesh portion 30. The mesh portion 30 may have multiple wires that intersect with each other, and the wires are fixed to each other at their intersections. The mesh portion 30 may have multiple corrugated wires with multiple peaks, and the peaks of adjacent wires are fixed to each other. In these cases, the space surrounded by the wires is the opening 31. A stent may be used as the mesh portion 30.

[0185] The opening formed in the cylindrical member described above may be a slit or a hole. The shape of the slit may be, for example, rectangular. The extending direction of the slit may be inclined with respect to the longitudinal direction x and radial direction y of the first shaft 10, or may be parallel to the longitudinal direction x and radial direction y of the first shaft 10. The slit may also be formed in a spiral shape. The shape of the hole may be, for example, a polygonal shape such as a triangular or rectangular shape, a circular shape, or the like.

[0186] 23 , the distal end member 20 may have an outer membrane 23 that is disposed outward of the mesh portion 30 in the radial direction y of the first shaft 10 and is made of a material that is less rigid than the material that makes up the mesh portion 30. A part or the entire mesh portion 30 may be embedded in the outer membrane 23. This makes it possible to prevent tissue damage that would occur if the mesh portion 30 came into direct contact with the tissue.

[0187] The outer membrane 23 is preferably tubular, with the mesh portion 30 disposed in its lumen. The distal end of the mesh portion 30 is preferably located proximal to the distal end of the outer membrane 23. It is more preferable that the entire mesh portion 30 be disposed in the lumen of the tubular outer membrane 23.

[0188] The outer membrane 23 can be made of any of the materials exemplified below as materials that can be used to make the balloon 60 .

[0189] The radiopaque portion 25 can be made of a material containing a radiopaque substance, such as lead, barium, iodine, tungsten, gold, platinum, iridium, stainless steel, titanium, or a cobalt-chromium alloy. The entire radiopaque portion 25 may be made of a radiopaque substance alone. The radiopaque portion 25 may also be made of a combination of a radiopaque substance and another material.

[0190] The second shaft 50 can be configured to have an inner cavity extending in the longitudinal direction x of the first shaft 10. As can be seen from Figures 21 to 26, the inner cavity of the second shaft 50 can be used as a passage for inserting the guide wire 1 or the like.

[0191] 21 to 26, the second shaft 50 may have a second inner shaft 51 and a second outer shaft 52. The second outer shaft 52 has an inner lumen and is preferably disposed in the inner lumen 10a of the first shaft 10. The second inner shaft 51 has an inner lumen in which the guide wire 1 is disposed and is preferably disposed in the inner lumen of the second outer shaft 52.

[0192] The second outer shaft 52 is preferably connected to an indeflator that injects a fluid to be supplied inside the balloon 60 .

[0193] The first shaft 10 and the second shaft 50 are preferably flexible, which allows the first shaft 10 and the second shaft 50 to be easily deformed to conform to the shape of the body cavity. In addition, the first shaft 10 and the second shaft 50 are preferably elastic in order to maintain their shape.

[0194] The shape of the first shaft 10 and the second shaft 50 may be, for example, a hollow cylindrical shape, a hollow polygonal prism shape, or the like.

[0195] The first shaft 10 and the second shaft 50 can be, for example, a hollow body formed by arranging one or more wires in a predetermined pattern; a hollow body with a resin coating on at least one of the inner and outer surfaces; a resin tube; or a combination of these, for example, a combination of these connected in the longitudinal direction. Examples of hollow bodies with 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 first shaft 10 and the second shaft 50 are resin tubes, the first shaft 10 and the second shaft 50 can be composed of a single layer or multiple layers. A portion of the first shaft 10 and the second shaft 50 in the longitudinal direction x or circumferential direction c of the first shaft 10 may be composed of a single layer, and the other portion may be composed of multiple layers.

[0196] The first shaft 10 and the second shaft 50 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 materials may be used alone or in combination of two or more. The first shaft 10 and the second shaft 50 may be made of the same material, or may be made of different materials.

[0197] The outer diameter of the first shaft 10 can be, for example, 1.0 mm or more, 1.1 mm or more, 1.2 mm or more, etc. The outer diameter of the first shaft 10 can also be, for example, 5.0 mm or less, 4.0 mm or less, 3.0 mm or less, etc., but is preferably 2.0 mm or less.

[0198] The inner diameter of the first shaft 10 can be, for example, 4.0 mm or less, 3.8 mm or less, 3.5 mm or less, etc. The inner diameter of the first shaft 10 can be, for example, 0.4 mm or more, 0.5 mm or more, 0.6 mm or more, etc., but is preferably 0.8 mm or more, and more preferably 1.2 mm or more. The inner diameter of the first shaft 10 is also preferably large enough to allow the second shaft 50 to pass through.

[0199] The balloon 60 is preferably made of a resin. Examples of resins that make up the balloon 60 include polyamide resin, polyester resin, polyurethane resin, polyolefin resin, vinyl chloride resin, silicone resin, and natural rubber. These may be used alone or in combination of two or more. Among these, polyamide resin, polyester resin, and polyurethane resin are preferred. From the viewpoint of thinning and flexibility of the balloon 60, an elastomer resin can be used.

[0200] The balloon 60 may have a distal sleeve portion 64 secured to the second inner shaft 51 and a proximal sleeve portion 65 secured to the second outer shaft 52 .

[0201] 22, 23, 25, and 26, when the balloon 60 is inflated, the main body 61 preferably has a portion 62 protruding from the first shaft 10 and a portion 63 located in the lumen 10a of the first shaft 10. When the balloon 60 is inflated, the portion 62 of the main body 61 protruding from the first shaft 10 preferably has a straight tube portion 62b, a distal tapered portion 62a located distal to the straight tube portion 62b, and a proximal tapered portion 62c located proximal to the straight tube portion 62b. The above-described configuration of the balloon 60 makes it easier for the straight tube portion 62b to come into contact with the lesion.

[0202] 22, it is preferable that the mesh section 300 has an abutment portion 24 that abuts against the straight tube portion 62b when the balloon 60 is inflated. This makes it easier to visualize the proximal end of the straight tube portion 62b, which is likely to abut against the lesion.

[0203] The contact portion 24 is preferably arranged so as to be parallel to the longitudinal direction of the balloon 60, the longitudinal direction x of the first shaft 10, the longitudinal direction of the second shaft 50, etc. Note that "parallel" as used here includes strict parallelism ±10°.

[0204] 24 and 25 , it is preferable that the inner diameter of a portion of the first shaft 10 when the balloon 60 is inflated is larger than the inner diameter of the portion of the first shaft 10 when the balloon 60 is deflated, and that the inner diameter of the fixing part 22 when the balloon 60 is inflated is smaller than the inner diameter of the portion of the first shaft 10 when the balloon 60 is inflated. This configuration makes it easier to suppress movement of the balloon 60 in the longitudinal direction x of the first shaft 10 when the balloon 60 is inflated with a portion of the main body part 61 protruding from the first shaft 10. For example, this can be implemented by having the first shaft 10 have an outer layer 15 and an inner layer 16 located inward of the outer layer 15 in the radial direction y of the first shaft 10, and the inner layer 16 being made of a material with a lower hardness than the outer layer 15. The hardness can be measured by measuring the repulsive force during compression, measuring the elastic modulus using a scanning probe microscope (SPM), measuring Rockwell hardness, measuring Shore hardness, etc., but it is preferably measured by measuring Shore hardness.

[0205] The length from the distal end to the proximal end of the catheter 100 can be, for example, 200 mm or more, 250 mm or more, 300 mm or more, etc. The length from the distal end to the proximal end of the catheter 100 can be, for example, 2500 mm or less, 2450 mm or less, 2400 mm or less, etc.

[0206] 20 , a hub 70 may be connected to the proximal portion of the first shaft 10. The first shaft 10 and the hub 70 may be fixed together. For example, the first shaft 10 and the hub 70 can be fixed together by bonding with an adhesive, welding, screws, or the like.

[0207] FIG. 20 discloses an embodiment in which a guidewire port 13 is formed midway from the distal end to the proximal end of the first shaft 10. The guidewire port 13 is in communication with the lumen 10a of the first shaft 10. FIG. 20 shows a so-called rapid exchange catheter 100. The first shaft 10 may have a first distal shaft portion 11 and a first proximal shaft portion 12 located proximally of the first distal shaft portion 11. The first distal shaft portion 11 and the first proximal shaft portion 12 may be separate members, with the proximal end of the member constituting the first distal shaft portion 11 connected to the distal end of the member constituting the first proximal shaft portion 12. Alternatively, the first distal shaft portion 11 and the first proximal shaft portion 12 may be formed from a single member.

[0208] Although not shown, the catheter 100 may be of a so-called over-the-wire type in which a lumen 10a is formed from the distal end to the proximal end of the first shaft 10. When the catheter 100 is of the over-the-wire type, it is preferable that the lumen 10a of the first shaft 10 extend in the longitudinal direction x of the catheter 100 to a position where the hub 70 is located.

[0209] The outer surface 10c of the first shaft 10 may be coated. As shown in Fig. 20, when the catheter 100 is of a rapid exchange type, the outer surface of at least one of the first distal shaft section 11 and the first proximal shaft section 12 may be coated, or the outer surfaces of both the first distal shaft section 11 and the first proximal shaft section 12 may be coated. When the catheter 100 is of an over-the-wire type, only a portion or the entire outer surface 10c of the first shaft 10 may be coated.

[0210] The coating applied to the outer surface 10c of the first shaft 10 can be a hydrophilic coating or a hydrophobic coating depending on the purpose. The coating can be applied by immersing the first shaft 10 in a hydrophilic or hydrophobic coating agent, by applying a hydrophilic or hydrophobic coating agent to the outer surface 10c of the first shaft 10, or by covering the outer surface 10c of the first shaft 10 with a hydrophilic or hydrophobic coating agent. Drugs or additives may be added to the coating agent.

[0211] 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.

[0212] 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.

[0213] This application claims the benefit of priority based on Japanese Patent Application No. 2024-050044 filed on March 26, 2024, the benefit of priority based on Japanese Patent Application No. 2024-050046 filed on March 26, 2024, and the benefit of priority based on Japanese Patent Application No. 2024-050047 filed on March 26, 2024. The entire contents of the specifications of Japanese Patent Application No. 2024-050044, Japanese Patent Application No. 2024-050046, and Japanese Patent Application No. 2024-050047 are incorporated herein by reference.

[0214] 1: Guidewire 10: First shaft 100: Catheter 10a: Lumen 10b: Inner surface 10c: Outer surface 10d: Distal end 11: First distal shaft portion 12: First proximal shaft portion 13: Guidewire port 14: Convex portion 15: Outer layer 16: Inner layer 20: Tip member 20a: Lumen 20b: Inner surface 20c: Outer surface 20d: Distal end 20e: Proximal end 21: Spiral portion 210: Spiral section 210a: Distal portion 210b: Proximal portion 211: First spiral portion 212: Second spiral portion 22: Fixation portion 23: Outer membrane 24: Contact portion 25: Radiopaque portion 26: Braided portion 260: Braided section 26a: Distal portion 26b: Proximal portion 27: Wire rod 271: First wire rod 272: Second wire rod 29: Ring-shaped member 30: Braided portion 300: Braided section 30a: Distal portion 30b: Proximal portion 31: Opening 32: Wire portion 50: Second shaft 51: Second inner shaft 52: Second outer shaft 60: Balloon 61: Main body portion 62: Portion protruding from first shaft 62a: Distal tapered portion 62b: Straight tube portion 62c: Proximal tapered portion 63: Portion located in the lumen of the first shaft 64: Distal sleeve portion 65: Proximal sleeve portion 66: Wing portion 70: Hub c: Circumferential direction of the first shaft x: Longitudinal direction of the first shaft y: Radial direction of the first shaft

Claims

1. A catheter comprising: a first shaft having a longitudinal direction and a radial direction and an inner lumen extending in the longitudinal direction; a tip member connected to the distal end of the first shaft, having an inner lumen communicating with the inner lumen of the first shaft, and equipped with a spiral portion having an X-ray opaque portion; a second shaft disposed in the inner lumen of the first shaft and the inner lumen of the tip member and moving in the longitudinal direction relative to the first shaft; and a balloon disposed in the distal portion of the second shaft, having a main body portion that expands and contracts in the radial direction, the length of which the main body portion protrudes from the first shaft being adjustable depending on the length of the lesion in the patient, wherein at least a portion of the spiral portion is disposed distal to the distal end of the first shaft, and the inner diameter of the spiral portion is expandable by expanding the balloon.

2. A catheter according to claim 1, wherein the tip member has a fixed portion at its proximal portion, the inner diameter of which does not expand when the balloon is expanded, and which is fixed to the first shaft.

3. A catheter as described in claim 1 or 2, wherein the tip member has an outer membrane arranged radially outward of the spiral portion and made of a material less rigid than the material making up the spiral portion.

4. A catheter according to claim 1 or 2, wherein when the balloon is in a deflated state, the balloon has a plurality of blades which are wound around the second shaft in the circumferential direction of the second shaft, and the winding direction of the spiral portion and the winding direction of the blades are the same in the circumferential direction of the second shaft.

5. A catheter as described in claim 1 or 2, wherein, when the balloon is inflated, the portion of the main body protruding from the first shaft has a straight tube portion, a distal tapered portion located distal to the straight tube portion, and a proximal tapered portion located proximal to the straight tube portion, and when the balloon is inflated, the spiral portion has an abutment portion that abuts against the straight tube portion.

6. A catheter according to claim 1 or 2, wherein the first shaft has a protrusion protruding radially inward.

7. A catheter according to claim 1 or 2, wherein the spiral portion is made of a material containing a shape memory alloy.

8. A catheter according to claim 1 or 2, wherein the helical pitch of the helical portion increases distally when the balloon is in a deflated state.

9. A catheter according to claim 1 or 2, wherein the cross-sectional area of ​​the spiral portion in a cross section perpendicular to the longitudinal direction decreases toward the distal side.

10. A catheter as described in claim 1 or 2, wherein the tip member is provided with a plurality of said spiral portions, the tip member has a spiral section in the longitudinal direction which is provided with said spiral portions, and the number of said spiral portions present in the proximal part of said spiral section is greater than the number of said spiral portions present in the distal part of said spiral section.

11. A catheter according to claim 1 or 2, wherein the tip member is provided with a plurality of said spiral portions, and the plurality of spiral portions includes a first spiral portion and a second spiral portion whose distal end is located proximal to the distal end of the first spiral portion.

12. A catheter as described in claim 2, wherein the inner diameter of a portion of the first shaft when the balloon is inflated is larger than the inner diameter of said portion of the first shaft when the balloon is inflated, and the inner diameter of the fixing part when the balloon is inflated is smaller than the inner diameter of said portion of the first shaft when the balloon is inflated.

13. A catheter according to claim 12, wherein the first shaft has an outer layer and an inner layer located radially inward from the outer layer, and the inner layer is made of a material having a lower hardness than the outer layer.

14. A catheter comprising: a first shaft having a longitudinal direction and a radial direction and an inner lumen extending in the longitudinal direction; a tip member connected to the distal end of the first shaft, having an inner lumen communicating with the inner lumen of the first shaft, and having a braided section comprising a braided portion having a radiopaque portion in the longitudinal direction; a second shaft disposed in the inner lumen of the first shaft and the inner lumen of the tip member and moving in the longitudinal direction relative to the first shaft; and a balloon disposed in the distal portion of the second shaft, having a main body portion that expands and contracts in the radial direction, the length of which the main body portion protrudes from the first shaft being adjustable depending on the length of the lesion in the patient, wherein at least a portion of the braided section is disposed distal to the distal end of the first shaft, and the inner diameter of the braided section is expandable by expanding the balloon.

15. A catheter according to claim 14, wherein the tip member has a fixed portion at its proximal portion, the inner diameter of which does not expand when the balloon is expanded, and which is fixed to the first shaft.

16. A catheter according to claim 14 or 15, wherein the tip member has an outer membrane arranged radially outward of the braided portion and made of a material less rigid than the material constituting the braided portion.

17. A catheter as described in claim 14 or 15, wherein, when the balloon is inflated, the portion of the main body protruding from the first shaft has a straight tube section, a distal tapered section located distal to the straight tube section, and a proximal tapered section located proximal to the straight tube section, and when the balloon is inflated, the braided section has an abutment section that abuts against the straight tube section.

18. A catheter according to claim 14 or 15, wherein the first shaft has a protrusion protruding radially inward.

19. A catheter according to claim 14 or 15, wherein the braided portion is made of a material containing a shape memory alloy.

20. A catheter according to claim 14 or 15, wherein the braid pitch of the braided portion increases toward the distal end when the balloon is deflated.

21. A catheter according to claim 14 or 15, wherein the braided portion has a plurality of wires, and in a cross section perpendicular to the longitudinal direction, the cross-sectional area of ​​the wires decreases toward the distal side.

22. A catheter as claimed in claim 14 or 15, wherein the braided portion has a plurality of wires, and the number of wires present in the proximal portion of the braided portion is greater than the number of wires present in the distal portion of the braided portion.

23. A catheter as described in claim 14 or 15, wherein the braided portion has a plurality of wires, and the plurality of wires includes a first wire and a second wire whose distal end is located proximal to the distal end of the first wire.

24. A catheter as described in claim 15, wherein the inner diameter of a portion of the first shaft when the balloon is inflated is larger than the inner diameter of said portion of the first shaft when the balloon is inflated, and the inner diameter of the fixing part when the balloon is inflated is smaller than the inner diameter of said portion of the first shaft when the balloon is inflated.

25. A catheter according to claim 24, wherein the first shaft has an outer layer and an inner layer located radially inward from the outer layer, and the inner layer is made of a material having a lower hardness than the outer layer.

26. A catheter comprising: a first shaft having a longitudinal direction and a radial direction and an inner lumen extending in the longitudinal direction; a tip member connected to the distal end of the first shaft, having an inner lumen communicating with the inner lumen of the first shaft, and having a mesh section provided with a mesh section having an X-ray opaque portion in the longitudinal direction; a second shaft disposed in the inner lumen of the first shaft and the inner lumen of the tip member and moving in the longitudinal direction relative to the first shaft; and a balloon disposed in the distal portion of the second shaft, having a main body portion that expands and contracts in the radial direction, and the protrusion length of the main body portion from the first shaft can be adjusted depending on the length of the lesion in the patient, wherein the mesh section has a plurality of openings radially communicating between the outside of the tip member and the inner lumen of the tip member, at least a portion of the mesh section is disposed distal to the distal end of the first shaft, and the inner diameter of the mesh section can be expanded by expanding the balloon.

27. A catheter according to claim 26, wherein the tip member has a fixed portion at its proximal portion, the inner diameter of which does not expand when the balloon is expanded, and which is fixed to the first shaft.

28. A catheter according to claim 26 or 27, wherein the tip member has an outer membrane arranged radially outward of the mesh portion and made of a material less rigid than the material constituting the mesh portion.

29. A catheter as described in claim 26 or 27, wherein, when the balloon is inflated, the portion of the main body protruding from the first shaft has a straight tube section, a distal tapered section located distal to the straight tube section, and a proximal tapered section located proximal to the straight tube section, and when the balloon is inflated, the mesh section has an abutment section that abuts against the straight tube section.

30. A catheter according to claim 26 or 27, wherein the first shaft has a protrusion protruding radially inward.

31. A catheter according to claim 26 or 27, wherein the mesh portion is made of a material containing a shape memory alloy.

32. A catheter as described in claim 26 or 27, wherein the mesh portion comprises a linear portion connected to the proximal end of the radiopaque portion and constituting a mesh, and the length of the radiopaque portion in the radial direction is longer than the length of the linear portion in the radial direction.

33. A catheter as described in claim 26 or 27, wherein, when the balloon is deflated, the average area of ​​the openings located in the distal part of the mesh portion is larger than the average area of ​​the openings located in the proximal part of the mesh portion.

34. A catheter as described in claim 27, wherein the inner diameter of a portion of the first shaft when the balloon is inflated is larger than the inner diameter of said portion of the first shaft when the balloon is inflated, and the inner diameter of the fixing part when the balloon is inflated is smaller than the inner diameter of said portion of the first shaft when the balloon is inflated.

35. A catheter according to claim 34, wherein the first shaft has an outer layer and an inner layer located radially inward from the outer layer, the inner layer being made of a material having a lower hardness than the outer layer.

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