Filter device

Abstract

To achieve a filter device having a filter that can be used in a state of being supported by a guide wire supporting another device.SOLUTION: A filter device includes a filter, a pusher, and a stopper. The filter can be in a contraction state and an extension state in which the filter extends in a radial direction from the contraction state. The pusher is arranged at a proximal end side of the filter and is used for pushing the filter to a distal end side. The stopper is attached to the filter and is formed with a space to which a guide wire is inserted. The stopper is configured to make a transition from a non-overlapping state of not overlapping with a specific portion in an axial direction, the specific portion being located closer to the distal end side than the stopper in the guide wire inserted to the space, to an overlapping state of overlapping with the specific portion in the axial direction, as the filter makes a transition from the contraction state to the extension state.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The technology disclosed herein relates to a filter device. [Background technology]

[0002] There is known a filter device that captures embolic debris in a biological lumen such as a blood vessel using a filter. For example, Patent Document 1 discloses a filter device having a delivery wire and a filter fixed to the delivery wire. In a filter device configured in this way, the filter is delivered to a desired position in a biological lumen by advancing the delivery wire distally, and after the procedure, the filter is retrieved by pulling the delivery wire proximally. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-213839 A Summary of the Invention [Problem to be solved by the invention]

[0004] There are cases where it is desired to use a filter supported by a guide wire that supports another device. For example, in atherectomy, a treatment method in which a vein lesion (a narrowed or blocked portion) is removed by rotating a rotor at high speed, it is preferable to place a filter on the distal (peripheral) side of the lesion to capture embolic debris that may be generated by removing the lesion. In such a case, the filter is used in a state supported by a guide wire that supports an atherectomy device. In the above-mentioned conventional filter device, the filter is fixed to a delivery wire, and therefore cannot be applied to a procedure in which the filter is used in a state supported by a guide wire.

[0005] It should be noted that this problem is not limited to atherectomy, but is a common problem when a filter and other devices are supported by a guidewire and used within a body lumen.

[0006] This specification discloses a technique that can solve the above-mentioned problems. [Means for solving the problem]

[0007] The technology disclosed in this specification can be realized, for example, in the following forms.

[0008] (1) A filter device disclosed in the present specification includes a filter, a pusher, and a stopper. The filter is configured to be capable of being in a contracted state and an expanded state in which the filter is radially expanded from the contracted state. The pusher is disposed on the base end side of the filter and is used to push the filter toward the distal end. The stopper is attached to the filter and has a space through which a guidewire is inserted. The stopper is configured to transition from a non-overlapping state in which the stopper does not overlap in the axial direction with a specific portion of the guidewire inserted into the space that is located distal to the stopper, to an overlapping state in which the stopper overlaps in the axial direction with the specific portion, as the filter transitions from the contracted state to the expanded state.

[0009] In this filter device, as the filter transitions from a contracted state to an expanded state, the stopper transitions from a non-overlapping state in which the stopper does not overlap with the specific portion of the guidewire in the axial direction to an overlapping state in which the stopper overlaps with the specific portion in the axial direction. Therefore, when retrieving the filter, the guidewire inserted into the space of the stopper is pulled toward the base end, the specific portion of the guidewire is brought into contact with the stopper, and the filter is moved toward the base end by the guidewire while maintaining this state. That is, the guidewire does not require special processing, such as providing a protrusion that interferes with the filter, and the filter can be retrieved using a general-purpose guidewire. In this way, according to this filter device, a filter device having a filter that can be used in a state supported by a guidewire that supports another device can be realized. Furthermore, according to this filter device, even when the filter is detached from the delivery device and used while being supported by the guidewire, the filter can be retrieved using a general-purpose guidewire instead of a dedicated one.

[0010] (2) In the above filter device, the stopper may include a plurality of wires, and may be configured such that, as the filter transitions from the contracted state to the expanded state, tips of at least some of the wires move toward a center of the stopper in an axial view, thereby transitioning from the non-overlapping state to the overlapping state. By adopting this configuration, it is possible to realize a configuration in which the stopper transitions from the non-overlapping state to the overlapping state as the filter transitions from the contracted state to the expanded state, while avoiding a complex configuration.

[0011] (3) In the above filter device, the stopper may be configured to maintain the overlapping state even when the filter transitions from the expanded state to the contracted state. By adopting this configuration, it is possible to prevent the filter from being accidentally detached from the retrieval device after the filter is housed in the retrieval device.

[0012] (4) In the above filter device, in the overlapping state, a minimum diameter of a space of the stopper through which the guidewire is inserted may be smaller than an outer diameter of the specific portion. By adopting this configuration, it is possible to reliably realize an overlapping state in which the stopper overlaps with the specific portion of the guidewire in the axial direction while avoiding a complicated configuration.

[0013] The technology disclosed in this specification can be realized in various forms, for example, in the form of a filter device, a medical instrument including a filter device, a manufacturing method thereof, or a method of using the same. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is an explanatory diagram illustrating a schematic configuration of a filter device 10 according to an embodiment of the present invention. [Diagram 2] FIG. 1 is an explanatory diagram showing in detail the configuration of a filter device 10 according to an embodiment of the present invention; [Diagram 3] FIG. 1 is an explanatory diagram showing in detail the configuration of a filter device 10 according to an embodiment of the present invention; [Figure 4] FIG. 1 is an explanatory diagram showing the configuration of the filter unit 100 in detail. [Diagram 5] FIG. 1 is an explanatory diagram showing the configuration of the filter unit 100 in detail. [Figure 6] FIG. 1 is an explanatory diagram showing the configuration of the filter unit 100 in detail. [Figure 7] FIG. 1 is an explanatory diagram showing the configuration of the filter unit 100 in detail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] A. Embodiment: A-1. Configuration of filter device 10: Fig. 1 is an explanatory diagram that shows a schematic configuration of a filter device 10 of the present embodiment. Fig. 1 shows the configuration of a filter unit 100 that constitutes the filter device 10 in an expanded state.

[0016] The filter device 10 of this embodiment is an apparatus for capturing embolic debris 62 that may cause blockage of the blood vessel 50 by filtering blood flowing through the blood vessel 50. The filter device 10 is used, for example, during atherectomy using an atherectomy device 40 including a rotor 42. More specifically, in order to capture embolic debris 62 that may be generated during atherectomy, which is a treatment method for scraping a lesion 60 (a narrowed or blocked portion) of the blood vessel 50 by rotating the rotor 42 of the atherectomy device 40 at high speed, a filter unit 100 of the filter device 10 is placed in an expanded state on the distal side (peripheral side) of the lesion 60. At this time, the filter unit 100 and the atherectomy device 40 are supported by one guide wire 200 for use.

[0017] 2 and 3 are explanatory diagrams showing in detail the configuration of filter device 10 of this embodiment. Fig. 2 shows the configuration of a longitudinal section (YZ section) of filter device 10, and Fig. 3 shows the configuration of the front of filter device 10. Figs. 2 and 3 show a state in which filter device 10 is housed in hollow section 312 of delivery catheter 310 and filter unit 100 is contracted (hereinafter referred to as a "contracted state during delivery"). The contracted state during delivery is an example of a contracted state within the scope of the claims.

[0018] 4 to 7 are explanatory diagrams showing the configuration of filter unit 100 in detail. Figures 4 and 6 show the configuration of a longitudinal section (YZ section) of filter unit 100, and Figures 5 and 7 show the configuration of filter unit 100 from the front. Figures 4 and 5 show a state in which filter unit 100 is pushed out of delivery catheter 310 and expanded (hereinafter referred to as the "expanded state"), and Figures 6 and 7 show a state in which filter unit 100 is housed in hollow section 322 of retrieval catheter 320 and contracted (hereinafter referred to as the "contracted state during retrieval"). The contracted state during retrieval is an example of the contracted state within the scope of the claims.

[0019] In each figure, the positive Z-axis direction side is the tip side (distal side) inserted into the body, and the negative Z-axis direction side is the base side (proximal side) operated by a technician such as a doctor. Each figure shows the filter device 10, etc. as a whole in a straight line substantially parallel to the Z-axis direction, but the filter device 10, etc. has a flexibility to the extent that it can be curved. In this specification, for the filter device 10, etc., the tip side end is referred to as the "tip", the tip and its vicinity are referred to as the "tip portion", the base side end is referred to as the "base end", and the base end and its vicinity are referred to as the "base portion".

[0020] Also, each figure shows a guidewire 200 supporting the filter device 10. The guidewire 200 has a core shaft 210, a coil body 220 covering the distal end of the core shaft 210, and a distal joint 242 and a proximal joint 244 joining the core shaft 210 and the coil body 220. The core shaft 210 has a large diameter section 218, a first tapered section 216 extending from the distal end of the large diameter section 218 toward the distal end while decreasing in diameter, a small diameter section 214 having the same diameter as the distal end of the first tapered section 216 and extending from the distal end toward the distal end, and a second tapered section 212 extending from the distal end of the small diameter section 214 toward the distal end while decreasing in diameter. The coil body 220 is arranged so as to cover at least a part of the outer periphery of the distal end side of the second tapered section 212 of the core shaft 210. The outer diameter D2 of the coil body 220 is larger than the outer diameter D1 of the small diameter portion 214 of the core shaft 210 (see FIGS. 3, 5 and 7).

[0021] As shown in FIG. 2, the filter device 10 includes a filter unit 100 and a pusher 130 .

[0022] The filter unit 100 is a portion to be placed distal to a lesion 60 in a blood vessel 50 (see FIG. 1).

[0023] Filter 110 is a part that exerts a filtering function in filter unit 100. Filter 110 includes a frame portion 112 and a sheet portion 114. For the sake of convenience, sheet portion 114 is shown by a dashed line in each drawing.

[0024] The frame portion 112 is a framework formed by assembling a plurality of wires made of, for example, a Ni-Ti alloy or stainless steel. A guidewire insertion space 118 through which the guidewire 200 is inserted is formed at a position approximately at the center of the frame portion 112 as viewed in the axial direction. The minimum diameter of the guidewire insertion space 118 formed in the frame portion 112 is larger than the outer diameter D2 of the coil body 220 of the guidewire 200.

[0025] The frame portion 112 is configured to be capable of being in a folded contracted state and an expanded state in which the frame portion 112 is expanded (deployed) in the radial direction from the contracted state. When the frame portion 112 is subjected to an external force that causes the frame portion 112 to contract in the radial direction when the frame portion 112 is housed in the hollow portion 312 of the delivery catheter 310 or the hollow portion 322 of the recovery catheter 320, the frame portion 112 is in a contracted state in which the frame portion 112 is folded in a rod shape (see Figs. 2 and 6), and when the frame portion 112 is pushed out of the hollow portion 312 of the delivery catheter 310 and is no longer subjected to the external force, the frame portion 112 is in an expanded state in which the frame portion 112 is expanded in the cage shape due to, for example, the shape memory force of the material and / or the biasing force of a spring or the like (see Fig. 4). In this embodiment, the frame portion 112 has a distal end annular portion 112a and a proximal end annular portion 112b. When the frame portion 112 is shifted from the contracted state to the expanded state, the diameter of the distal end annular portion 112a does not change, while the diameter of the proximal end annular portion 112b increases.

[0026] The sheet portion 114 is a bag-shaped member attached to the frame portion 112 so as to cover the frame portion 112. The sheet portion 114 has a plurality of holes 116 (see FIG. 1) formed therein, the size of which is set to allow blood to pass through but not embolic debris 62 to pass through.

[0027] In this way, filter unit 100 expands and contracts in accordance with the expansion and contraction of frame portion 112 of filter 110. As shown in Fig. 1, when filter unit 100 is in an expanded state, the outer periphery of filter 110 comes into close contact with the inner wall of blood vessel 50, making it possible for sheet portion 114 of filter 110 to filter blood flowing through blood vessel 50.

[0028] The stopper 120 is configured by assembling a plurality of wires made of, for example, a Ni-Ti alloy or stainless steel into a cylindrical shape, and is attached to the distal end of the filter 110. A guidewire insertion space 128 through which the guidewire 200 is inserted is formed at the approximate center position of the stopper 120 as viewed in the axial direction. The configuration of the stopper 120 will be described in detail later.

[0029] 2, pusher 130 is a tubular member having a hollow portion 132 through which guidewire 200 is inserted, and is disposed on the proximal end side of filter 110 constituting filter unit 100. Pusher 130 is used to push the proximal end of filter unit 100 toward the distal end to push filter unit 100 toward the distal end.

[0030] A-2. Detailed configuration of stopper 120: Next, a detailed configuration of the stopper 120 constituting the filter unit 100 will be described. As described above, the stopper 120 is configured by assembling a plurality of wires into a cylindrical shape. More specifically, the stopper 120 has a base end frame 124 in which wires are assembled into a frame shape, and four axial wires 122 extending from the base end frame 124 to the tip side. The four axial wires 122 are arranged circumferentially when viewed in the axial direction. The plurality of axial wires 122 is an example of a plurality of wires in the claims.

[0031] 3, 5 and 7, guidewire insertion space 128 formed in stopper 120 is a gap between the tips of each axial wire 122. Stopper 120 is attached to frame portion 112 of filter 110, and the minimum diameter L1 of guidewire insertion space 128 formed in stopper 120 changes as filter 110 (filter unit 100) expands and contracts.

[0032] 3, when the filter unit 100 is in a contracted state during delivery, the minimum diameter L1 of the guidewire insertion space 128 of the stopper 120 is larger than the outer diameter D2 of the coil body 220 of the guidewire 200. In other words, the stopper 120 is in a non-overlapping state in the axial direction with the coil body 220 located on the distal side of the stopper 120 in the guidewire 200 inserted into the guidewire insertion space 128. Therefore, in this state, the coil body 220 of the guidewire 200 can pass through the guidewire insertion space 128 of the stopper 120. The coil body 220 of the guidewire 200 is an example of a specific portion in the claims.

[0033] 5, when the filter unit 100 transitions from the contracted state at the time of delivery to the expanded state, the base end frame 124 of the stopper 120 is deformed with the expansion of the frame portion 112 of the filter 110, and as a result, the tip portions of the axial wires 122 move toward the center of the stopper 120 as viewed in the axial direction, and the minimum diameter L1 of the guidewire insertion space 128 becomes smaller. Specifically, the minimum diameter L1 of the guidewire insertion space 128 of the stopper 120 in this state is smaller than the outer diameter D2 of the coil body 220 of the guidewire 200 and is larger than the outer diameter D1 of the small diameter portion 214 of the core shaft 210 of the guidewire 200. In other words, the stopper 120 transitions to an overlapping state in which the stopper 120 overlaps in the axial direction with the coil body 220 located distal to the stopper 120 in the guidewire 200 inserted into the guidewire insertion space 128. Therefore, in this state, the small diameter portion 214 of the core shaft 210 of the guidewire 200 can pass through the guidewire insertion space 128 of the stopper 120, but the coil body 220 of the guidewire 200 cannot pass through.

[0034] 7, even when the filter unit 100 transitions from the expanded state to the retrieval contracted state, the minimum diameter L1 of the guidewire insertion space 128 of the stopper 120 is maintained in a state smaller than the outer diameter D2 of the coil body 220 of the guidewire 200 and larger than the outer diameter D1 of the small diameter portion 214 of the core shaft 210 of the guidewire 200. In other words, the stopper 120 is maintained in an overlapping state in which the stopper 120 and the coil body 220 of the guidewire 200 overlap in the axial direction. Therefore, in this state, the small diameter portion 214 of the core shaft 210 of the guidewire 200 can pass through the guidewire insertion space 128 of the stopper 120, but the coil body 220 of the guidewire 200 cannot pass through it. In this way, a configuration in which the minimum diameter L1 of the guide wire insertion space 128 of the stopper 120 is maintained at a small value even when the filter unit 100 transitions from the expanded state to the contracted state during retrieval can be achieved, for example, by setting the rigidity of the stopper 120 when the filter unit 100 is in the expanded state higher than the rigidity of the frame portion 112 of the filter 110, or by setting the inner diameter of the hollow portion 322 of the retrieval catheter 320 larger than the inner diameter of the hollow portion 312 of the delivery catheter 310.

[0035] A-3. How to use the filter device 10: Next, a method of using the filter device 10 of this embodiment will be described with reference to Figures 1 to 7. First, a guidewire 200 is inserted into a blood vessel 50 and passed through a lesion 60 (see Figure 1).

[0036] 2, delivery catheter 310 carrying filter device 10 is advanced along guidewire 200 until filter unit 100 reaches a position distal to (distal side of) lesion 60. When filter device 10 is delivered, guidewire 200 is inserted through guidewire insertion space 118 of filter 110, guidewire insertion space 128 of stopper 120, and hollow portion 132 of pusher 130. The inner diameter of hollow portion 312 of delivery catheter 310 is set to be smaller than the outer diameter of filter 110 of filter unit 100 when expanded, and when filter device 10 is housed within hollow portion 312 of delivery catheter 310, filter unit 100 is in a contracted state.

[0037] Next, pusher 130 is pressed toward the distal end, thereby pushing filter unit 100 including filter 110 out of delivery catheter 310. As a result, filter 110 of filter unit 100 expands on the distal side of lesion 60 in blood vessel 50 (see FIGS. 1 and 4). Delivery catheter 310 is then pulled toward the proximal end and collected. As a result, filter unit 100 is placed in blood vessel 50 in a state detached from delivery catheter 310.

[0038] Next, the atherectomy device 40 including the rotor 42 is advanced along the guidewire 200 to the position of the lesion 60, and the rotor 42 is rotated at high speed to scrape the lesion 60 (see FIG. 1). At this time, since the filter 110 of the filter unit 100 is placed in the blood vessel 50 in an expanded state distal to the lesion 60, embolic debris 62 that may be released into the blood vessel 50 as a result of the atherectomy is captured by the filter 110. After the atherectomy is completed, the atherectomy device 40 is withdrawn toward the proximal end and collected.

[0039] Next, the recovery catheter 320 is advanced along the guidewire 200 to a position immediately before the filter unit 100. Then, the guidewire 200 is pulled toward the proximal end. As described above, when the filter unit 100 is in the expanded state, the minimum diameter L1 of the guidewire insertion space 128 of the stopper 120 is smaller than the outer diameter D2 of the coil body 220 of the guidewire 200 and is larger than the outer diameter D1 of the small diameter portion 214 of the core shaft 210 of the guidewire 200. In other words, the stopper 120 is in an overlapping state in which it overlaps with the coil body 220 of the guidewire 200 in the axial direction. Therefore, when the guidewire 200 is pulled toward the proximal end, the proximal end of the coil body 220 of the guidewire 200 abuts against the stopper 120, and the filter unit 100 including the stopper 120 is pulled toward the proximal end. When filter unit 100 moves toward the proximal end and abuts against the distal end of recovery catheter 320, frame portion 112 of filter 110 is folded and contracted by the external force from recovery catheter 320. Filter unit 100 moves further toward the proximal end in the contracted state, and is housed within hollow portion 322 of recovery catheter 320 (see FIG. 6).

[0040] As described above, even when filter unit 100 transitions from the expanded state to the retrieval contracted state, minimum diameter L1 of guidewire insertion space 128 of stopper 120 is maintained in a state smaller than outer diameter D2 of coil body 220 of guidewire 200 and larger than outer diameter D1 of small diameter portion 214 of core shaft 210 of guidewire 200. In other words, stopper 120 is maintained in an overlapping state in which stopper 120 overlaps coil body 220 of guidewire 200 in the axial direction. Therefore, after filter unit 100 is housed in hollow portion 322 of retrieval catheter 320, filter unit 100 is inhibited from moving toward the distal end relative to guidewire 200, and erroneous detachment of filter unit 100 from retrieval catheter 320 is inhibited.

[0041] Finally, retrieval catheter 320 containing filter unit 100 is moved toward the proximal end along guidewire 200, thereby retrieving filter unit 100 and retrieval catheter 320.

[0042] A-4. Advantages of this embodiment: As described above, the filter device 10 of the present embodiment includes the filter 110, the pusher 130, and the stopper 120. The filter 110 is configured to be capable of being in a contracted state and an expanded state radially expanded from the contracted state. The pusher 130 is disposed on the base end side of the filter 110 and is used to push the filter 110 toward the distal end side. The stopper 120 is attached to the filter 110 and is formed with a guidewire insertion space 128 through which the guidewire 200 is inserted. The stopper 120 is configured to transition from a non-overlapping state in which the stopper 120 does not overlap with the coil body 220 located distal to the stopper 120 in the guidewire 200 inserted in the guidewire insertion space 128 in the axial direction to an overlapping state in which the stopper 120 overlaps with the coil body 220 in the axial direction as the filter 110 transitions from the contracted state to the expanded state.

[0043] In this way, in the filter device 10 of the present embodiment, as the filter 110 transitions from a contracted state to an expanded state, the stopper 120 transitions from a non-overlapping state in which the stopper 120 does not overlap the coil body 220 of the guidewire 200 in the axial direction to an overlapping state in which the stopper 120 overlaps the coil body 220 in the axial direction. Therefore, when retrieving the filter 110 (filter unit 100), the guidewire 200 inserted into the guidewire insertion space 128 of the stopper 120 is pulled toward the base end side, the coil body 220 of the guidewire 200 is brought into contact with the stopper 120, and the filter 110 is moved toward the base end side by the guidewire 200 while maintaining this state. That is, the guidewire 200 does not require special processing such as providing a protrusion that interferes with the filter 110, and the filter 110 can be retrieved using a general-purpose guidewire 200. In this way, according to the filter device 10 of the present embodiment, it is possible to realize a filter device 10 having a filter 110 that can be used in a state supported by the guidewire 200 that supports another device. Furthermore, according to the filter device 10 of this embodiment, even when the filter 110 is detached from the delivery device (delivery catheter 310) and supported by the guide wire 200 for use, the filter 110 can be retrieved using a general-purpose guide wire 200 rather than a dedicated one.

[0044] Moreover, in the filter device 10 of the present embodiment, the stopper 120 includes a plurality of axial wires 122. The stopper 120 is configured to transition from a non-overlapping state to an overlapping state as the filter 110 transitions from a contracted state to an expanded state, by moving at least some of the tips of the plurality of axial wires 122 toward the center of the stopper 120 as viewed in the axial direction. Therefore, according to the filter device 10 of the present embodiment, it is possible to realize a configuration in which the stopper 120 transitions from a non-overlapping state to an overlapping state as the filter 110 transitions from a contracted state to an expanded state, while avoiding a complicated configuration.

[0045] Furthermore, in filter device 10 of the present embodiment, stopper 120 is configured to maintain the overlapping state even when filter 110 transitions from the expanded state to the contracted state. Therefore, according to filter device 10 of the present embodiment, after filter unit 100 including filter 110 is housed in a retrieval device (retrieval catheter 320), it is possible to prevent filter unit 100 from accidentally becoming detached from the retrieval device.

[0046] Furthermore, in the filter device 10 of the present embodiment, in the overlapping state, the minimum diameter L1 of the guidewire insertion space 128 of the stopper 120 is smaller than the outer diameter D2 of the coil body 220 of the guidewire 200. Therefore, according to the filter device 10 of the present embodiment, it is possible to reliably achieve an overlapping state in which the stopper 120 and the coil body 220 of the guidewire 200 overlap in the axial direction while avoiding a complicated configuration.

[0047] B. Variations: The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[0048] The configuration of the filter device 10 in the above embodiment is merely an example and can be modified in various ways. For example, in the above embodiment, the stopper 120 is attached to the tip of the filter 110, but the stopper 120 may be attached to a portion of the filter 110 other than the tip.

[0049] In the above embodiment, the stopper 120 includes a plurality of axial wires 122, and is configured to transition from a non-overlapping state to an overlapping state by moving the tips of all of the axial wires 122 toward the center of the stopper 120 in the axial direction as the filter 110 transitions from the contracted state to the expanded state, but the stopper 120 may have another configuration. For example, the stopper 120 may be configured such that the tips of some of the axial wires 122 move toward the center of the stopper 120 in the axial direction as the filter 110 transitions from the contracted state to the expanded state. In addition, the stopper 120 does not need to have a plurality of axial wires 122 as long as it is configured to transition from a non-overlapping state to an overlapping state as the filter 110 transitions from the contracted state to the expanded state.

[0050] In the above embodiment, stopper 120 is configured to maintain the overlapping state even when filter 110 transitions from the expanded state to the contracted state, but stopper 120 may also be configured to transition from the overlapping state to the non-overlapping state as filter 110 transitions from the expanded state to the contracted state.

[0051] In the above embodiment, the stopper 120, in the overlapping state, overlaps in the axial direction with the coil body 220 of the guidewire 200 inserted into the guidewire insertion space 128; however, in the overlapping state, the stopper 120 may also overlap in the axial direction with another portion of the guidewire 200 inserted into the guidewire insertion space 128 that is located further distal than the stopper 120.

[0052] In the above embodiment, an example has been described in which the filter device 10 is used together with the atherectomy device 40 while being supported by the guidewire 200, but the technology disclosed in this specification is similarly applicable to a case in which the filter device 10 is used together with another device, such as a balloon or a stent, that is supported by the guidewire 200. Furthermore, the technology disclosed in this specification is similarly applicable to a filter device 10 that is used while being supported by the guidewire 200 in a biological lumen (digestive organs, such as the bile duct, gallbladder, pancreas, esophagus, duodenum, small intestine, large intestine, etc., blood vessels, ureter, trachea, etc.). [Explanation of symbols]

[0053] 10: Filter device 40: Atherectomy device 42: Rotating body 50: Blood vessel 60: Lesion 62: Embolic fragment 100: Filter unit 110: Filter 112: Frame section 112a: Distal annular section 112b: Base annular section 114: Sheet section 116: Hole 118: Guidewire insertion space 120: Stopper 122: Axial wire 124: Base frame 128: Guidewire insertion space 130: Pusher 132: Hollow section 200: Guidewire 210: Core shaft 212: Second taper section 214: Small diameter section 216: First taper section 218: Large diameter section 220: Coil body 242: Distal joint section 244: Base joint section 310: Delivery catheter 312: Hollow section 320: Recovery catheter 322: Hollow section

Claims

1. A filter device comprising: a filter configured to be capable of being in a contracted state and an expanded state radially expanded from the contracted state; a pusher disposed on the proximal end side of the filter for pushing the filter toward the distal end side; a stopper attached to the filter and having a space through which a guide wire is inserted; wherein the stopper is configured to shift from a non-overlapping state in which it does not overlap axially with a specific portion located on the distal end side of the stopper in the guide wire inserted into the space as the filter shifts from the contracted state to the expanded state, to an overlapping state in which it overlaps axially with the specific portion.

2. The filter device according to claim 1, wherein the stopper includes a plurality of wires, and is configured to shift from the non-overlapping state to the overlapping state as at least a part of the tips of the plurality of wires move toward the center of the stopper in a view in the axial direction as the filter shifts from the contracted state to the expanded state.

3. The filter device according to claim 1 or claim 2, wherein the stopper is configured to maintain the overlapping state even when the filter shifts from the expanded state to the contracted state.

4. The filter device according to claim 1 or claim 2, wherein in the overlapping state, the minimum diameter of the space through which the guide wire of the stopper is inserted is smaller than the outer diameter of the specific portion.

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