Balloon catheter

Abstract

To provide a balloon catheter to be easily returned to an original wrapping shape when a balloon is contracted.SOLUTION: In a balloon catheter 10, a balloon 12 is internally divided into a plurality of spaces by a plurality of division films for connecting an outer shaft 20 to an inner wall of the balloon 12. The outer shaft 20 includes hole parts 30, 31, 32, 33 for allowing each one of the spaces to communicate with a lumen of the outer shaft 20. A shaft part 11 includes a fluid control shaft 22 which is arranged along an inner wall of the outer shaft 20 and is movable in a longitudinal direction with respect to the outer shaft 20. The fluid control shaft 22 allows the hole parts 30, 31, 32, 33 to be successively changed from a closed state into an open state from a distal end side to a proximal end side of the shaft part 11 by a movement in a longitudinal direction with respect to the outer shaft 20.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a balloon catheter having a balloon at the tip of a shaft portion. [Background technology]

[0002] Balloon catheters are widely used to treat lesions (stenosis) that occur in biological lumens. A balloon catheter usually has a long shaft and a balloon that is provided at the tip of the shaft and can expand in the radial direction. The balloon is contracted and reaches a target location inside the body via a narrow biological lumen, and then expanded to expand the lesion.

[0003] The shaft portion has a configuration in which an inner shaft is disposed in the lumen of the outer shaft, and an expansion fluid such as a contrast agent can be injected into the balloon through the space between the outer shaft and the inner shaft. After the balloon expands in the biological lumen, the expansion fluid is decompressed to cause the balloon to contract, and the balloon is housed in the guiding catheter. In order to smoothly house the balloon in the guiding catheter, it is desirable that the expansion fluid be decompressed to cause the balloon to rewrap back to the wrapping shape it had before expansion.

[0004] An example of a balloon catheter having a structure that makes it easier for the balloon to return to its original wrapping shape when it is deflated is disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2009-297143 A Summary of the Invention [Problem to be solved by the invention]

[0006] The balloon has a straight section with the same diameter in the center in the long axis direction, and tapered sections with both ends in the long axis direction that decrease in diameter toward both ends. When the balloon is deflated, negative pressure is applied to the entire balloon, so the straight section with a thin wall is likely to deform locally and significantly. In addition, the boundary between the straight section and the tapered section is harder than the surrounding area due to the influence of the balloon molding, so it is difficult to deform until the end when the balloon is deflated. For this reason, when the balloon is deflated, it starts to bend from the center of the straight section, while the boundary between the straight section and the tapered section is difficult to deform and functions like a support, so the center of the straight section is deformed into a significantly bent shape. In particular, this effect is large in balloons with a long length along the long axis direction, and there is a possibility that the balloon will not return to its original wrapping shape when deflated. Even if the balloon is made easier to rewrap by shaping as in Patent Document 1, there is a possibility that the balloon with a long length along the long axis direction will not be able to be rewrapped to its original wrapping shape.

[0007] The present invention has been made to solve the above-mentioned problems, and has an object to provide a balloon catheter that can be reliably rewrapped to its original wrapping shape when the balloon is deflated. [Means for solving the problem]

[0008] To achieve the above object, (1) a balloon catheter is provided having a balloon at the tip of a shaft portion having an inner shaft disposed in the lumen of an outer shaft, the balloon being divided into a plurality of spaces by a plurality of dividing membranes connecting the outer shaft to the inner wall of the balloon, the outer shaft having holes connecting each of the plurality of spaces to the lumen of the outer shaft, the shaft portion having a fluid control shaft disposed along the inner wall of the outer shaft and movable along the longitudinal direction relative to the outer shaft or rotatable relative to the outer shaft, the fluid control shaft sequentially changes the holes from a closed state to an open state from the tip side to the base end side of the shaft portion by moving in the longitudinal direction relative to the outer shaft or by rotating relative to the outer shaft. Effect of the Invention

[0009] In the balloon catheter configured as described above, the divided spaces of the balloon can be sequentially connected to the lumen of the outer shaft from the distal end side to the proximal end side by moving or rotating the fluid control shaft in the longitudinal direction relative to the outer shaft, so that the balloon can be sequentially deflated from the distal end side to the proximal end side. In the balloon catheter, the balloon is sequentially deflated from the distal end side to the proximal end side, so that the boundary between the straight part and the tapered part, which is harder than the surrounding area due to the influence of the balloon molding, is first deflated, and rewrapping can be started reliably from the distal end side of the balloon, and the folding into a wing shape can be propagated to the proximal end side, so that the balloon can be rewrapped to return to the original wrapping shape reliably. In addition, in the balloon catheter, the balloon is divided into a plurality of spaces along the longitudinal direction, so that the balloon can be prevented from bending when each space is decompressed, and the balloon can be rewrapped more reliably to the original wrapping shape.

[0010] (2) In the balloon catheter of (1) above, the split membrane may be bonded to the outer shaft at a position different from that at the position where the split membrane is bonded to the inner wall of the balloon in the longitudinal direction of the shaft portion, thereby making it possible to prevent the split membrane from interfering with the rewrapping of the balloon.

[0011] (3) In the balloon catheter of (2) above, the joint portion of the divided membrane to the outer shaft may be located closer to the tip of the shaft portion than the joint portion to the inner wall of the balloon. This allows each divided space of the balloon to have a shape that follows the direction in which the balloon contracts, so that the balloon can be smoothly contracted and rewrapped back to its original wrapping shape with certainty.

[0012] (4) In the balloon catheter of any one of (1) to (3) above, the hole may be provided across the plurality of spaces, thereby simplifying the structure of the outer shaft.

[0013] (5) In the balloon catheter of any one of (1) to (3) above, the hole may be provided for each of the spaces, thereby making it possible to reliably separate the multiple spaces of the balloon.

[0014] (6) In any of the balloon catheters (1) to (5) above, the fluid control shaft may be rotatable relative to the outer shaft, and the fluid control shaft may have communication holes with different opening widths along the longitudinal direction of the shaft portion. In this way, by rotating the fluid control shaft relative to the outer shaft, the communication holes are sequentially brought into communication with the holes of the outer shaft from the distal end to the proximal end, and the balloon can be sequentially deflated from the distal end to the proximal end.

[0015] (7) In the balloon catheter of (6) above, the fluid control shaft may have an expansion communication hole portion, which has the same opening width along the longitudinal direction of the shaft portion, at a circumferential position different from the communication hole portion. In this way, by rotating the fluid control shaft to a position where the expansion communication hole portion communicates with the hole portion of the outer shaft, the entire space of the balloon can be communicated with the lumen of the outer shaft, thereby expanding the entire balloon. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is an overall front view of the balloon catheter. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of the vicinity of the tip portion of the balloon catheter when the balloon is inflated. [Diagram 3] 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 4] FIG. 2 is an enlarged cross-sectional view of the proximal end portion of the balloon catheter. [Diagram 5] FIG. 2 is an enlarged cross-sectional view of the vicinity of the tip portion of the balloon catheter when the balloon is deflated. [Figure 6] FIG. 2 is an enlarged cross-sectional view of the vicinity of the tip of the balloon catheter in a state in which only the first space of the balloon is deflated. [Figure 7] FIG. 2 is an enlarged cross-sectional view of the vicinity of the tip of the balloon of the balloon catheter in a state in which only the first space and the second space are deflated. [Figure 8] FIG. 2 is an enlarged cross-sectional view of the vicinity of the tip of the balloon of the balloon catheter in a state in which only the first space, the second space, and the third space are deflated. [Figure 9] FIG. 2 is a cross-sectional view of the balloon catheter with the balloon in a deflated state, taken along a plane perpendicular to the longitudinal axis of the balloon catheter. [Figure 10] 13 is an enlarged cross-sectional view of the vicinity of the tip of a balloon catheter having a hole in an outer shaft according to a modified example. FIG. [Figure 11] FIG. 1 is an overall front view of a rapid exchange type balloon catheter. [Figure 12] FIG. 12 is an enlarged cross-sectional view of the vicinity of an opening of a shaft portion of the balloon catheter of FIG. 11. [Figure 13] FIG. 13 is a perspective view of the vicinity of a tip portion of a fluid control shaft according to a modified example. [Figure 14] 10A to 10D are cross-sectional views of the shaft portion in states where the fluid control shaft is changed from angular positions D1 to D5 at the positions of the holes of the outer shaft. [Figure 15] FIG. 11 is an enlarged cross-sectional view of the vicinity of the tip of a balloon catheter, in which (a) shows the state in which the fluid control shaft has been rotated to angular position D1, (b) shows the state in which the fluid control shaft has been rotated to angular position D2, (c) shows the state in which the fluid control shaft has been rotated to angular position D3, (d) shows the state in which the fluid control shaft has been rotated to angular position D4, and (e) shows the state in which the fluid control shaft has been rotated to angular position D5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the dimensional ratios in the drawings may be exaggerated for convenience of explanation and may differ from the actual ratios. In addition, in this specification, the side of the balloon catheter 10 that is inserted into a body lumen is referred to as the "distal end" or "distal side", and the side that is operated by the operator is referred to as the "base end" or "base side".

[0018] As shown in Fig. 1, a balloon catheter 10 has a balloon 12 that can expand and contract in the radial direction at the tip end of a long shaft section 11, and a hub 13 is provided at the base end of the shaft section 11. The balloon 12 can be expanded in the radial direction by an expansion fluid injected from the hub 13. A fluid control shaft 22 that constitutes the shaft section 11 is exposed on the base end side from the base end of the hub 13.

[0019] 2 and 3, in the shaft portion 11, the inner shaft 21 is concentrically disposed in the inner cavity of the outer shaft 20. Inside the outer shaft 20 and outside the inner shaft 21, a fluid control shaft 22 is disposed along the inner wall of the outer shaft 20. The fluid control shaft 22 can move along the longitudinal direction relative to the outer shaft 20. Between the outer wall of the inner shaft 21 and the inner wall of the fluid control shaft 22, an expansion lumen 20a is formed, through which the expansion fluid flows. Inside the inner shaft 21, a guidewire lumen 21a is formed, through which a guidewire is inserted.

[0020] The distal end of the outer shaft 20 extends to the distal end of the balloon 12. The base end and distal end of the balloon 12 are each joined to the outer surface of the outer shaft 20. The distal end of the inner shaft 21 extends distally beyond the outer shaft 20. The portion of the inner shaft 21 extending distally beyond the outer shaft 20 is covered with a distal tip 25. The distal tip 25 has a guidewire lumen 25a, which communicates with the guidewire lumen 21a of the inner shaft 21, forming a continuous cavity for inserting a guidewire.

[0021] The balloon 12 has a straight section 40 with the same diameter at the center in the longitudinal direction, and tapered sections 41 on the proximal and distal ends of the straight section 40, each tapering in diameter toward the end of the balloon 12. A first divided membrane 42, a second divided membrane 44, and a third divided membrane 46 are provided inside the balloon 12, connecting the outer wall of the outer shaft 20 to the inner wall of the straight section 40 of the balloon 12. As a result, the internal space of the balloon 12 is divided from the distal end to the proximal end into a first space 43, a second space 45, a third space 47, and a fourth space 48.

[0022] The first divided membrane 42 has a shaft-side bonding portion 42a that is connected to the outer shaft 20 and a balloon-side bonding portion 42b that is connected to the inner wall of the balloon 12, and the shaft-side bonding portion 42a is located closer to the tip of the shaft portion 11 than the balloon-side bonding portion 42b. Therefore, the first divided membrane 42 has a shape that is a part of the side of a cone that is convex toward the tip. The second divided membrane 44 also has a shape similar to that of the first divided membrane 42, with the shaft-side bonding portion 44a being located closer to the tip of the shaft portion 11 than the balloon-side bonding portion 44b. The third divided membrane 46 also has a shape similar to that of the first divided membrane 42, with the shaft-side bonding portion 46a being located closer to the tip of the shaft portion 11 than the balloon-side bonding portion 46b. Because the first divided membrane 42, the second divided membrane 44, and the third divided membrane 46 have such shapes and arrangements, each divided membrane 42, 44, 46 expands and contracts in accordance with the balloon 12, thereby preventing each divided membrane from impeding rewrapping when the balloon 12 is deflated.

[0023] In addition, the joint portion of each divided membrane to the outer shaft 20 may be located closer to the proximal end than the joint portion to the balloon 12 .

[0024] The outer shaft 20 has a first hole 30 opening into a first space 43 of the balloon 12, a second hole 31 opening into a second space 45 of the balloon 12, a third hole 32 opening into a third space 47 of the balloon 12, and a fourth hole 33 opening into a fourth space 48 of the balloon 12. In Fig. 2, the tip position of the fluid control shaft 22 along the inner wall of the outer shaft 20 is located on the tip side of the first hole 30, and the first hole 30, the second hole 31, the third hole 32, and the fourth hole 33 are all blocked by the fluid control shaft 22. For this reason, the expansion lumen 20a and the spaces 43, 45, 46, and 48 of the balloon 12 are not in communication with each other.

[0025] As shown in FIG. 4, the hub 13 has a hub body 50 and an anti-kink protector 51 provided at the tip of the hub body 50. The base end of the outer shaft 20 is located inside the hub body 50, and the fluid control shaft 22 extends to the base end side beyond the hub body 50. The inner shaft 21 is fixed to the base end of the hub 13 by a waterproof valve 26. The fluid control shaft 22 has an elongated hole portion 22a in a portion located inside the hub 13, which communicates between the inside and outside of the fluid control shaft 22. Therefore, the expansion lumen 20a of the shaft portion 11 communicates with the inside of the hub 13. The elongated hole portion 22a has a shape that is long in the longitudinal direction because the fluid control shaft 22 moves along the longitudinal direction.

[0026] The hub body 50 has a base end port 53 through which the shaft portion 11 is inserted, and an injection port 52 that communicates with the expansion lumen 20a inside the hub body 50. An injection device such as an indeflator having an expansion fluid is connected to the injection port 52, and the expansion fluid can be injected into the expansion lumen 20a or the expansion fluid can be sucked out from the expansion lumen 20a.

[0027] A contrast agent can be used as the expansion fluid for expanding the balloon 12. Note that the expansion fluid is not limited to this and may be a gas or a liquid, for example, a gas such as helium gas, CO2 gas, or O2 gas, or a liquid such as physiological saline can also be used.

[0028] The outer shaft 20, the inner shaft 21, and the fluid control shaft 22 constituting the shaft portion 11 are preferably made of a material having a certain degree of flexibility. Examples of such materials include polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or mixtures of two or more of these, soft polyvinyl chloride resin, polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane, fluororesins such as polytetrafluoroethylene, silicone rubber, latex rubber, etc. Note that the material forming the shaft portion 11 is not limited to these.

[0029] The balloon 12 may be made of polyolefins such as polyamide, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more of these, or thermoplastic resins such as soft polyvinyl chloride resin, polyamide elastomer, polyester, polyester elastomer, polyurethane, and fluororesin. Note that the material for forming the balloon 12 is not limited to these.

[0030] Next, the expansion and contraction of the balloon 12 will be described. When expanding and contracting the balloon 12, the surgeon can hold the fluid control shaft 22 at the hand and move it in the longitudinal direction. As shown in FIG. 5, when expanding the balloon 12, the fluid control shaft 22 is moved to the base end side and the tip is positioned on the base end side of the fourth hole 33, so that the first hole 30, the second hole 31, the third hole 32, and the fourth hole 33 are all in an open state, and the expansion lumen 20a is in a state of communication with the first space 43, the second space 45, the third space 47, and the fourth space 48. In this state, by injecting an expansion fluid into the expansion lumen 20a, the expansion fluid flows into the first space 43, the second space 45, the third space 47, and the fourth space 48, and the balloon 12 can be expanded.

[0031] Once the balloon 12 is expanded, the fluid control shaft 22 is moved toward the tip as shown in FIG. 2 and positioned so that its tip is located further toward the tip side than the first hole 30, whereby the first hole 30, the second hole 31, the third hole 32, and the fourth hole 33 are blocked, and the expanded state of the balloon 12 can be maintained.

[0032] When deflating the balloon 12, first, as shown in Fig. 6, the fluid control shaft 22 is moved toward the base end from the state shown in Fig. 2, and arranged so that the tip is located on the base end side of the first hole portion 30 and on the tip end side of the second hole portion 31. As a result, the first hole portion 30 is opened and the first space 43 communicates with the expansion lumen 20a, while the second hole portion 31, the third hole portion 32, and the fourth hole portion 33 maintain a closed state. In this state, the expansion fluid is sucked from the expansion lumen 20a, whereby the first space 43 contracts through the first hole portion 30. At this time, since the second hole portion 31, the third hole portion 32, and the fourth hole portion 33 are closed, the second space 45, the third space 47, and the fourth space 48 maintain an expanded state without contracting.

[0033] After the first space 43 is contracted, as shown in Fig. 7, the fluid control shaft 22 is moved toward the base end so that the tip is located closer to the base end than the second hole portion 31 and closer to the tip end than the third hole portion 32. As a result, the second hole portion 31 is opened and the second space 45 communicates with the expansion lumen 20a, while the third hole portion 32 and the fourth hole portion 33 maintain a closed state. In this state, the second space 45 is contracted through the second hole portion 31 by sucking the expansion fluid from the expansion lumen 20a. At this time, since the third hole portion 32 and the fourth hole portion 33 are closed, the third space 47 and the fourth space 48 are not contracted and maintain an expanded state.

[0034] After the second space 45 has been contracted, as shown in Fig. 8, the fluid control shaft 22 is moved toward the base end so that its tip is located closer to the base end than the third hole portion 32 and closer to the tip end than the fourth hole portion 33. As a result, the third hole portion 32 is opened and the third space 47 communicates with the expansion lumen 20a, while the fourth hole portion 33 maintains a closed state. In this state, the expansion fluid is sucked from the expansion lumen 20a, whereby the third space 47 contracts through the third hole portion 32. At this time, since the fourth hole portion 33 is closed, the fourth space 48 does not contract and maintains an expanded state.

[0035] After the third space 47 has been deflated, as shown in Fig. 5, the fluid control shaft 22 is moved toward the base end so that its tip is positioned closer to the base end than the fourth hole portion 33. This opens the fourth hole portion 33 and puts the fourth space 48 in communication with the expansion lumen 20a. In this state, the expansion fluid is sucked from the expansion lumen 20a, causing the fourth space 48 to contract through the fourth hole portion 33. This causes the balloon 12 to completely deflate.

[0036] In this way, by moving the fluid control shaft 22 in the longitudinal direction, the first hole portion 30 to the fourth hole portion 33 can be opened in sequence, and the spaces of the balloon 12 corresponding to each hole portion can be contracted. That is, in the balloon catheter 1 of this embodiment, the balloon 12 is divided into a plurality of spaces along the longitudinal direction, and these spaces can be contracted in sequence from the tip side, so that rewrapping is reliably started from the tip side of the balloon 12. The rewrapping started from the tip side of the balloon 12 is reliably induced to the entire balloon 12 into a rewrapped shape having a plurality of wing portions 12a as shown in FIG. 9 by propagating the folded state of the wing to the base end side. In addition, since the balloon 12 is divided into a plurality of spaces along the longitudinal direction, the length of each space along the longitudinal direction can be shortened, and the bending of the shape of the balloon 12 due to the pressure reduction in the space can be reduced. As a result, the balloon 12 is reliably rewrapped into the wrapping shape it had before expansion.

[0037] As shown in FIG. 10, the holes 35 provided in the outer shaft 20 may be continuous along the longitudinal direction and communicate with the first space 43, the second space 45, the third space 47, and the fourth space 48 of the balloon 12, respectively.

[0038] Next, a catheter 70 according to a modified example will be described. As shown in Fig. 11, the catheter 70 has a balloon 72 at the tip end of a shaft portion 71, and a hub 73 at the base end of the shaft portion 71. A fluid control shaft 82 constituting the shaft portion 71 is exposed from the base end of the hub 73. The shaft portion 71 has an opening 71a near the tip side through which a guide wire 75 is introduced. In other words, this catheter 70 is a so-called rapid exchange type.

[0039] In the catheter 70, the configuration near the balloon 72 is the same as that of the catheter 10 in FIG. 1, and therefore description thereof will be omitted. As shown in FIG. 12, the base end of the inner shaft 81 is exposed to the outer circumferential surface of the outer shaft 80 to form an opening 71a. The fluid control shaft 82 has a long hole portion 82a that is long along the long axis so as not to interfere with the inner shaft 81 when moving along the long axis direction. The long axis length of the long hole portion 82a is equal to or longer than the distance from the tip of the first hole portion 30 to the base end of the fourth hole portion 33 when the fluid control shaft 82 has a plurality of holes as shown in FIG. 2. The long axis length of the long hole portion 82a is equal to or longer than the long axis length of the hole portion 35 when the fluid control shaft 82 has holes that are continuous along the long axis direction as shown in FIG. 10. By providing the long hole portion 82a with such a long axis length, the fluid control shaft 82 can move in the axial direction, and the spaces in the balloon 72 can be communicated by the movement of the fluid control shaft 82.

[0040] Next, a balloon catheter 100 having a fluid control shaft 112 according to a modified example will be described. In this balloon catheter 100, the fluid control shaft 112 is rotatable relative to the outer shaft 110, and the rotation relative to the outer shaft 110 can sequentially change the hole of the shaft portion 101 from a closed state to an open state.

[0041] 13, the fluid control shaft 112 has an expansion communication hole portion 130 and a contraction communication hole portion 131 formed at different circumferential positions. The expansion communication hole portion 130 extends along the long axis direction and has the same opening width along the long axis direction. The contraction communication hole portion 131 extends along the long axis direction and is formed so that the opening width narrows from the tip end side to the base end side.

[0042] 14, the angular position of the fluid control shaft 112 at which the first hole portion 120, the second hole portion 121, the third hole portion 122, and the fourth hole portion 123 of the outer shaft 110 all communicate with the expansion communicating hole portion 130 of the fluid control shaft 112 is defined as D1. When the fluid control shaft 112 is in the angular position D1, the expansion lumen 110a can communicate with the first space 140, the second space 141, the third space 142, and the fourth space 143 of the balloon 102, as shown in FIG. 15(a). Therefore, by setting the fluid control shaft 112 to the angular position D1, an expansion fluid can be injected from the expansion lumen 110a into the balloon 102, thereby expanding the balloon 102.

[0043] When deflating the balloon 102, the fluid control shaft 112 is rotated to an angular position D2, so that the first hole 120 and the contraction communication hole 131 communicate with each other, the contraction communication hole 131 does not communicate with the second hole 121 at the position of the second hole 121, the contraction communication hole 131 does not communicate with the third hole 122 at the position of the third hole 122, and the contraction communication hole 131 does not communicate with the fourth hole 123 at the position of the fourth hole 123. Therefore, by sucking the expansion fluid from the expansion lumen 110a, the first space 140 of the balloon 102 can be contracted as shown in FIG. 15(b).

[0044] By rotating the fluid control shaft 112 to angle position D3, the second hole 121 and the contraction communication hole 131 communicate with each other, the contraction communication hole 131 does not communicate with the third hole 122 at the position of the third hole 122, and the contraction communication hole 131 does not communicate with the fourth hole 123 at the position of the fourth hole 123. Therefore, by sucking the expansion fluid from the expansion lumen 110a, the second space 141 of the balloon 102 can be contracted as shown in FIG. 15(c).

[0045] By rotating the fluid control shaft 112 to angle position D4, the third hole 122 and the contraction communication hole 131 communicate with each other, as shown in Fig. 14, and at the position of the fourth hole 123, the contraction communication hole 131 does not communicate with the fourth hole 123. Therefore, by sucking the expansion fluid from the expansion lumen 110a, the third space 142 of the balloon 102 can be contracted, as shown in Fig. 15(d).

[0046] By rotating the fluid control shaft 112 to an angular position D5, the fourth hole portion 123 and the contraction communicating hole portion 131 communicate with each other, as shown in Fig. 14. Therefore, by sucking the expansion fluid from the expansion lumen 110a, the fourth space 143 of the balloon 102 can be contracted, as shown in Fig. 15(e).

[0047] In this way, by providing the fluid control shaft 112 with the contraction communicating hole portion 131 having different opening widths along the longitudinal axis, the rotation of the fluid control shaft 112 relative to the outer shaft 11 can sequentially change the hole portion of the shaft portion 101 from a closed state to an open state from the tip end side to the base end side.

[0048] As described above, the (1) balloon catheter 10 according to this embodiment is a balloon catheter 10 having a balloon 12 at the tip of a shaft portion 11 in which an inner shaft 21 is disposed in a lumen of an outer shaft 20, and the balloon 12 is divided into a plurality of spaces 43, 45, 47, 48 by a plurality of dividing membranes 42, 44, 46 that connect the outer shaft 20 and the inner wall of the balloon 12, and the outer shaft 20 communicates with each of the plurality of spaces 43, 45, 47, 48 and the lumen of the outer shaft 20. The shaft portion 11 has a fluid control shaft 22 that is disposed along the inner wall of the outer shaft 20 and is movable in the longitudinal direction relative to the outer shaft 20 or rotatable relative to the outer shaft 20, and the fluid control shaft 22 sequentially changes the holes 30, 31, 32, 33 from a closed state to an open state from the distal end side to the proximal end side of the shaft portion 11 by moving in the longitudinal direction relative to the outer shaft 20 or by rotating relative to the outer shaft 20. In the balloon catheter 10 configured in this manner, the divided spaces 43, 45, 47, 48 of the balloon 12 can be sequentially connected to the lumen of the outer shaft 20 from the distal end side to the proximal end side by moving or rotating the fluid control shaft 22 in the longitudinal direction relative to the outer shaft 20, so that the balloon 12 can be deflated sequentially from the distal end side. In the balloon catheter 10, the balloon 12 is successively deflated from the tip side, so that the boundary between the straight portion 40 and the tapered portion 41, which is harder than the surrounding area due to the effect of molding the balloon 12, is deflated first, and rewrapping is started reliably from the tip side of the balloon 12, and the folding into a wing shape is propagated to the base end side, so that the balloon 12 can be rewrapped reliably to return to its original wrapped shape. Also, in the balloon catheter 10, the balloon 12 is divided into a plurality of spaces 43, 45, 47, 48 along the longitudinal direction, so that bending of the balloon 12 when each of the spaces 43, 45, 47, 48 is reduced, and the balloon 12 can be rewrapped more reliably to its original wrapped shape.

[0049] (2) In the balloon catheter 10 described above in (1), the divided membranes 42, 44, 46 may be arranged such that the joining portion to the outer shaft 20 and the joining portion to the inner wall of the balloon 12 are located at different positions in the longitudinal direction of the shaft portion 11. This makes it possible for the balloon catheter 10 to prevent the divided membranes 42, 44, 46 from interfering with the rewrapping of the balloon 12.

[0050] (3) In the balloon catheter 10 described above in (2), the divided membranes 42, 44, 46 may be arranged so that their joints with the outer shaft 20 are closer to the tip of the shaft portion 11 than their joints with the inner wall of the balloon 12. This allows each of the divided spaces 43, 45, 47, 48 of the balloon 12 to have a shape that follows the direction in which the balloon 12 contracts, so that the balloon 12 can be smoothly contracted and reliably rewrapped back to its original wrapping shape.

[0051] (4) In any one of the balloon catheters 10 described above in (1) to (3), the hole 35 may be provided across a plurality of spaces 43, 45, 47, and 48. This allows the structure of the outer shaft 20 to be simplified.

[0052] (5) In the balloon catheter 10 of any of the above (1) to (3), the holes 30, 31, 32, and 33 may be provided for each of the spaces 43, 45, 47, and 48. This allows the multiple spaces 43, 45, 47, and 48 of the balloon 12 to be reliably separated.

[0053] (6) In the balloon catheter 100 of any of (1) to (5) above, the fluid control shaft 112 is rotatable relative to the outer shaft 110, and the fluid control shaft 112 may have communication hole portions 131 with different opening widths along the longitudinal direction of the shaft portion 101. As a result, by rotating the fluid control shaft 112 relative to the outer shaft 110, the communication hole portions 131 can be sequentially communicated with the holes 120, 121, 122, and 123 of the outer shaft 110 from the distal end side to the proximal end side, and the balloon 102 can be sequentially deflated from the distal end side to the proximal end side.

[0054] (7) In the balloon catheter 100 described above in (6), the fluid control shaft 112 may have an expansion communication hole 130 having the same opening width along the longitudinal direction of the shaft portion 101 at a circumferential position different from the communication hole 113. With this, by rotating the fluid control shaft 112 to a position where the expansion communication hole 130 communicates with the holes 120, 121, 122, 123 of the outer shaft 110, all of the spaces 140, 141, 142, 143 of the balloon 102 can be communicated with the lumen of the outer shaft 110, and the entire balloon 102 can be expanded.

[0055] The present invention is not limited to the above-described embodiment, and various modifications can be made by those skilled in the art within the technical concept of the present invention. [Explanation of symbols]

[0056] 10 Balloon Catheter 11 Shaft section 12. Balloon 13. Hub 20 Outer shaft 20a extended lumen 21 Inner shaft 21a Guidewire lumen 22 Fluid control shaft 22a Long hole part 30 1st hole 31 2nd hole 32 3rd hole 33 4th hole 40 Straight section 41 Tapered section 42 1st division membrane 43 1st space 44 Second division membrane 45 Second space 46 Third division membrane 47 Third space 48 4th space 50 Hub body 51 Anti-kink protector 52 Injection port 52a lumen 53 Proximal port

Claims

1. A balloon catheter having a balloon at a distal end of a shaft portion in which an inner shaft is disposed in a lumen of an outer shaft, The balloon is divided into a plurality of spaces by a plurality of dividing membranes connecting the outer shaft and the inner wall of the balloon, the outer shaft has holes that communicate each of the spaces with an inner cavity of the outer shaft, the shaft portion has a fluid control shaft that is disposed along an inner wall of the outer shaft and is movable along a longitudinal direction relative to the outer shaft or is rotatable relative to the outer shaft; A balloon catheter in which the fluid control shaft sequentially changes the hole portion from a closed state to an open state from the tip side to the base end side of the shaft portion by moving in the longitudinal direction relative to the outer shaft or by rotating relative to the outer shaft.

2. The balloon catheter according to claim 1 , wherein the split membrane has a joint portion to the outer shaft and a joint portion to the inner wall of the balloon at different positions in the longitudinal axis direction of the shaft portion.

3. The balloon catheter according to claim 2 , wherein a joint portion of the split membrane to the outer shaft is located closer to the distal end of the shaft portion than a joint portion of the split membrane to the inner wall of the balloon.

4. The balloon catheter according to any one of claims 1 to 3, wherein the hole is provided across the plurality of spaces.

5. The balloon catheter according to any one of claims 1 to 3, wherein the hole is provided for each of the spaces.

6. the fluid control shaft is rotatable relative to the outer shaft; The balloon catheter according to claim 5 , wherein the fluid control shaft has communication hole portions with different opening widths along the longitudinal direction of the shaft portion.

7. 7. The balloon catheter according to claim 6, wherein the fluid control shaft has an expansion communication hole portion, the expansion communication hole portion having the same opening width along the longitudinal axis of the shaft portion, at a circumferential position different from that of the communication hole portion.

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