Patent Publication Number: US-2022233212-A1

Title: Medical device and treatment method for crushing object in body lumen

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 16/124,681 filed Sep. 7, 2018, which is a continuation of International Application No. PCT/JP2017/009016 filed on Mar. 7, 2017, and claims priority to Japanese Application No. 2016-045553 filed on Mar. 9, 2016, the entire content of each of which is incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a medical device and a treatment method using the medical device for crushing an object in a body lumen. 
     BACKGROUND ART 
     In a case where a thrombus occurs in a body lumen, it is necessary to promptly remove the thrombus. An example of a thrombus that occurs in the body lumen includes a deep vein thrombosis due to a thrombus in a vein in a deep portion of a body, such as a femoral vein or a popliteal vein. As a medical treatment method for the deep vein thrombosis, a method has been known for removing a thrombus by inserting an elongated tubular body of a medical device into a blood vessel, injecting a medicine such as a thrombolytic agent in an embolus, and dissolving the thrombus. 
     Since a medical treatment method of injecting a medicine for removing a thrombus entails a side effect such as bleeding, there is proposed a medical treatment method in which a member of a wire rod is provided at a distal portion of a shaft inserted into a blood vessel is rotated, and thereby the thrombus that comes into contact with the member is mechanically broken and removed (for example, refer to U.S. Pat. No. 5,766,191). Consequently, it is not necessary to inject a medicine or it is possible to reduce the medicine usage. 
     The member that mechanically breaks the thrombus is a bent wire rod. It is preferable that the wire rod is able to be deformed into a linear shape in order to reach a target position. Hence, a first end portion of the wire rod is fixed to a shaft portion, but a second end portion of the wire rod is not fixed to the shaft portion. Therefore, when the shaft portion is rotated, the wire rod comes into contact with the thrombus, thereby receiving a reaction force, and is twisted and deformed. Thus, the range in which the wire rod is able to break the thrombus continually changes. 
     SUMMARY OF INVENTION 
     The disclosure herein provides a medical device and a treatment method using the medical device by which it is possible to appropriately maintain a range in which it is possible to break an object formed in a body lumen. 
     According to the disclosure, there is provided a medical device for crushing an object in a body lumen by being inserted into the corresponding body lumen, the medical device including: an elongated shaft portion that is rotatably driven; a crushing unit provided with bendable wire rods and is rotatable together with the shaft portion; and a sliding unit that is fixed to each of end portion of the wire rods on at least one of a distal side and a proximal side thereof and is interlocked with the shaft portion so as to be slidable in an axial direction of the shaft portion. The shaft portion is provided with a contact portion that comes into contact with the sliding unit during rotation and limits the relative rotation of the shaft portion and the sliding unit. After the sliding unit is attached to the contact portion, the sliding unit rotates in the same direction as the shaft portion along with the rotation of the shaft portion. 
     According to the another aspect of the disclosure, there is provided a treatment method for crushing an object formed in a lesion area in a body lumen by using the medical device described above, the treatment method including: inserting the shaft portion into the body lumen and delivering the crushing unit to the lesion area; rotating the shaft portion and causing the sliding unit to be attached to the contact portion of the shaft portion; and simultaneously rotating an end portion of the crushing unit on a distal side and an end portion of the crushing unit on a proximal side by the shaft portion, causing the crushing unit to come into contact with the object, and crushing the g object. 
     In the medical device and the treatment method configured as described above, the shaft portion rotates, and thereby the contact portion of the shaft portion comes into contact with the sliding unit such that the relative rotation of the shaft portion and the sliding unit is limited. Consequently, the crushing unit is unlikely to be twisted even when receiving an external force in a rotating direction and is unlikely to be deformed, and thus it is possible to appropriately maintain a range in which the crushing unit can crush the object in the body lumen. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view showing a medical device according to an exemplary embodiment. 
         FIG. 2  is a perspective view showing a distal portion of the medical device. 
         FIG. 3  is an enlarged perspective view showing the distal portion of the medical device. 
         FIG. 4  is a longitudinal-sectional view showing the distal portion of the medical device. 
         FIG. 5  is a cross-sectional view taken along line A-A in  FIG. 2 . 
         FIG. 6  is an exploded perspective view showing constituent components of a sliding unit according to the exemplary embodiment. 
         FIG. 7(A)  shows a state in which the medical device is inserted into the blood vessel, and  FIG. 7(B)  shows a state in which a crushing unit of the medical device is exposed in the blood vessel. 
         FIG. 8  is a longitudinal-sectional view showing a state in which a thrombus is crushed by the medical device. 
         FIG. 9  is an enlarged longitudinal-sectional view of the distal portion of the medical device, which shows a state in which the crushed thrombus is aspirated to an opening portion of a shaft outer tube. 
         FIG. 10  is an enlarged longitudinal-sectional view of the distal portion of the medical device, which shows a process in which the thrombus aspirated to the opening portion of the shaft outer tube is severed by a shaft inner tube. 
         FIG. 11  is an enlarged longitudinal-sectional view of the distal portion of the medical device, which shows a state in which the thrombus severed by the shaft inner tube is cut by a cutting portion. 
         FIG. 12  is an enlarged longitudinal-sectional view of the distal portion of the medical device, which shows a process in which the thrombus cut by the cutting portion is aspirated to a proximal side of the shaft inner tube. 
         FIG. 13  is a cross-sectional view showing a first modification example of the medical device. 
         FIG. 14  is a cross-sectional view showing a second modification example of the medical device. 
         FIG. 15(A)  shows a third modification example in which each of the shaft portion and the sliding unit has an elliptic cross-sectional shape, and  15 (B) shows a fourth modification example in which each of the shaft portion and the sliding unit has a quadrangular cross-sectional shape. 
         FIG. 16  is a cross-sectional view showing a fifth modification example of the medical device. 
         FIG. 17  is a plan view showing a sixth modification example of the medical device. 
         FIG. 18  is a perspective view showing a seventh modification example of the medical device. 
         FIG. 19  is a cross-sectional view taken along line B-B in  FIG. 18 . 
         FIG. 20  is a perspective view showing an eighth modification example of the medical device. 
         FIG. 21  is a plan view showing a ninth modification example of the medical device. 
         FIG. 22  is a plan view showing a distal portion in the ninth modification example. 
         FIG. 23(A)  shows a state in which the crushing unit is accommodated in an outer sheath when the crushing unit in the ninth modification example is expanded, and  FIG. 23(B)  shows a state in which the crushing unit is released from the outer sheath when the crushing unit in the ninth modification example is expanded. 
         FIG. 24(A)  shows a state in which the crushing unit is partially accommodated in the outer sheath when the crushing unit in the ninth modification example is retracted, and  FIG. 24(B)  shows a state in which the crushing unit is completely accommodated in the outer sheath when the crushing unit in the ninth modification example is retracted. 
         FIG. 25(A)  shows a state in which the crushing unit is partially accommodated in the outer sheath when the crushing unit in the ninth modification example is retracted, and  FIG. 25(B)  shows a state in which the crushing unit is completely accommodated in the outer sheath when the crushing unit in the ninth modification example is retracted. 
         FIG. 26  is a plan view showing a tenth modification example of the medical device. 
         FIG. 27(A)  shows a state in which the crushing unit is accommodated in an outer sheath when the crushing unit in the tenth modification example is expanded,  FIG. 27(B)  shows a state in which the crushing unit is partially released from the outer sheath when the crushing unit in the tenth modification example is expanded, and  FIG. 27(C)  shows a state in which the crushing unit is completely released from the outer sheath when the crushing unit in the tenth modification example is expanded. 
         FIG. 28(A)  shows a state in which the crushing unit is partially accommodated in the outer sheath when the crushing unit in the tenth modification example is retracted, and  FIG. 28(B)  shows a state in which the crushing unit is completely accommodated in the outer sheath when the crushing unit in the tenth modification example is retracted. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, an exemplary embodiment of the disclosure will be described with reference to the figures. A medical device  10  according to the exemplary embodiment is inserted into a blood vessel and is used for a treatment of crushing and removing a thrombus in a deep-vein thrombosis. In this specification, a side of the device, on which the device is inserted into a blood vessel, is referred to as a “distal side”, and a hand side, on which an operation is performed, is referred to as a “proximal side”. Note that an object to be removed is not absolutely limited to the thrombus but can correspond to any object that can be present in a body lumen. Note that a dimensional ratio in the figures is enlarged depending on the description and the ratio is different from an actual ratio in some cases. 
     As shown in  FIGS. 1 to 4 , the medical device  10  includes a shaft portion  20  that is elongated and is configured to be rotatably driven, an outer sheath  90  that is able to accommodate the shaft portion  20 , a sliding unit  50  that is capable of sliding with respect to the shaft portion  20 , and a crushing unit  60  that is configured to be rotated by the shaft portion  20 . The medical device  10  further includes a rotation-drive unit  70  that rotates the shaft portion  20 , a hub  80  that is provided at a proximal end portion of the shaft portion  20 , and a syringe  100  that is connected to a proximal side of the hub  80 . 
     The shaft portion  20  includes a shaft outer tube  21  (first tubular body), a shaft inner tube  30 , and a tubular body  40  (a second tubular body) for a guide wire, each of which has an elongated hollow shape. 
     The shaft outer tube  21  has a distal end portion that is a distal portion of the shaft portion  20  and a proximal end portion that is positioned in the rotation-drive unit  70 . The shaft outer tube  21  is capable of reciprocating rotation in a circumferential direction by the rotation-drive unit  70 , i.e., clockwise and counter-clockwise. However, the shaft outer tube  21  is not limited to reciprocating and may rotate in one direction. The shaft outer tube  21  is provided with a lumen  24  (first lumen) that accommodates the shaft inner tube  30  therein. An inner diameter of the shaft outer tube  21  is larger than an outer diameter of the shaft inner tube  30 . The shaft outer tube  21  is provided with an opening portion  22  having an elongated shaped hole in an axial direction in the vicinity of the distal portion such that an inside and an outside of the shaft outer tube  21  communicate with each other. The distal end portion of the shaft outer tube  21  is provided with a cylindrical attachment portion  23  that blocks the lumen  24 . A proximal surface of the attachment portion  23  is an attachment surface  23 A that is opposite to a distal surface of the shaft inner tube  30 . The attachment surface  23 A is positioned to be closer to a distal side than the distal end portion of the opening portion  22  of the shaft outer tube  21 . The attachment portion  23  is formed by stainless steel or the like in the exemplary embodiment. 
     The shaft inner tube  30  is coaxially housed in a hollow lumen of the shaft outer tube  21 . The shaft inner tube  30  is provided with an aspiration lumen  32  which is in a negative pressure state such that an aspiration force is generated. The shaft inner tube  30  is capable of moving with respect to the shaft outer tube  21  in the axial direction. A distal end portion of the shaft inner tube  30  is positioned at a position of a proximal end portion of the opening portion  22  of the shaft outer tube  21  or is positioned to be closer to the proximal side than the proximal end portion of the opening portion  22 . A proximal end portion of the shaft inner tube  30  extends to be closer to the proximal side than the proximal end portion of the shaft outer tube  21  and is connected to the hub  80 . The syringe  100  is connected to the hub  80 , thereby performing aspiration in the aspiration lumen  32  of the shaft inner tube  30 , and thus it is possible to cause the aspiration lumen  32  to be in the negative pressure state. A cutting portion  31  is provided in the aspiration lumen  32  in the distal end portion of the shaft inner tube  30 . The cutting portion  31  has a sharp blade  31 A on the distal side, which is a thin metal plate and has a width corresponding to a diameter of the shaft inner tube  30 . 
     A distal end surface of the blade  31 A and a distal end surface of the shaft inner tube  30  are flush, that is, there is no step therebetween. Therefore, when the distal surface of the shaft inner tube  30  is attached to the attachment surface  23 A of the attachment portion  23 , the blade  31 A is also attached to the attachment surface  23 A. The shaft inner tube  30  is capable of reciprocating in the axial direction at least from a position of the shaft outer tube  21  closer to a proximal side (a position shown in  FIG. 4 ) than a proximal end of the opening portion  22  to a position at which the shaft inner tube is attached to the attachment surface  23 A of the attachment portion  23 . The cutting portion  31  is disposed to divide a cross-sectional shape of a hollow portion of the shaft inner tube  30  into two portions. 
     The tubular body  40  for guide wire is disposed to be fixed to the shaft outer tube  21  along an outer surface of a distal portion of the shaft outer tube  21 . The tubular body  40  for guide wire is provided with a guide wire lumen  41  (second lumen) into which a guide wire is insertable. 
     It is preferable that the shaft outer tube  21  is flexible and can transmit acting power of rotation from the proximal side to the distal side. It is preferable that the shaft inner tube  30  is flexible and can transmit acting power of a front and rear reciprocating motion from the proximal side to the distal side. It is preferable that the tubular body  40  for guide wire is flexible. Constituent materials of the shaft outer tube  21 , the shaft inner tube  30 , and the tubular body  40  for guide wire are not particularly limited; however, it is preferable to use a tubular body having a shape of a multi-layer coil such as a three-layer coil formed in alternate right, left, and right winding directions or a tubular body in which a reinforcing member such as a wire rod is buried, the wire rod being made of a polyolefin such as polyethylene or polypropylene, a polyamide, a polyester such as polyethylene terephthalate, a fluoropolymer such as ethylene-tetrafluoroethylene copolymer (ETFE), polyether ether ketone (PEEK), polyimide, or a combination thereof, for example. 
     The outer sheath  90  is able to accommodate the shaft portion  20  and is able to accommodate the crushing unit  60  while reducing a diameter of the crushing unit  60  interlocked with the shaft portion  20 . The outer sheath  90  is capable of sliding with respect to the shaft portion  20  in the axial direction. 
     A constituent material of the outer sheath  90  is not particularly limited, however, examples of the material include, preferably, a polyolefin such as polyethylene or polypropylene, a polyamide, polyester such as polyethylene terephthalate, a fluoropolymer such as ETFE, PEEK, polyimide, or the like. In addition, the outer sheath may be formed by a plurality of materials or may have a reinforcing member such as a wire rod which is buried therein. 
     The crushing unit  60  is provided at a distal portion of the shaft outer tube  21 . The crushing unit  60  is provided with a plurality of spiral units  61 . The spiral units  61  are all twisted in the same circumferential direction along the axial direction of the shaft outer tube  21 . Each of the proximal end portions of the spiral units  61  is fixed to the shaft outer tube  21  at an interlock portion  62 . Each of the distal end portions of the spiral units  61  is fixed to the sliding unit  50  that is slidable with respect to the shaft portion  20 . The positions at which the spiral units  61  are fixed to the interlock portion  62  and the sliding unit  50  are different from each other in the circumferential direction. The spiral units  61  are aligned in the circumferential direction at a position at which the central portions of the bent spiral units in the axial direction are separated from the shaft outer tube  21  in a radial direction. Consequently, the entire crushing unit  60  uniformly bulges in the circumferential direction. When the shaft portion  20  rotates, the crushing unit  60  rotates along with the shaft portion. Therefore, it is possible to crush a thrombus in a blood vessel or to agitate the crushed thrombus. 
     The spiral units  61  constituting the crushing unit  60  are made of a thin metal wire having flexibility. The crushing unit  60  is in a state of being housed inside the outer sheath  90  until the shaft portion  20  is inserted into a target site. When the spiral units  61  are accommodated in the outer sheath  90 , the sliding unit  50 , with which the distal portions of the spiral units  61  are interlocked, is moved to the distal side along the shaft portion  20 . Consequently, the bulge of the spiral units  61  at the central portion thereof in the axial direction is decreased, and the spiral units approach an outer peripheral surface of the shaft outer tube  21 . Consequently, the spiral units  61  are reduced in diameter and are accommodated inside the outer sheath  90 . After the shaft portion  20  is inserted into the target site of a blood vessel, the outer sheath  90  is caused to slide with respect to the shaft portion  20  to the proximal side, and thereby the crushing unit  60  is exposed outside the outer sheath  90  and is expanded by its own elastic force. Here, the sliding unit  50  moves along the shaft portion  20  to the proximal side. Therefore, it is desirable that the spiral units  61  are made of a shape-memory material. Examples of constituent materials of the spiral units  61  include, preferably, a shape-memory alloy to which a shape-memory effect or superelasticity through heat treatment is imparted, stainless steel, or the like. It is preferable to use a Ni—Ti-based alloy, a Cu—Al—Ni-based alloy, a Cu—Zn—Al-based alloy, a combination thereof, or the like as the shape-memory alloy. 
     As shown in  FIGS. 2, 5, and 6 , the sliding unit  50  has a C-shaped cross section that is orthogonal to the axial direction of the shaft portion  20 . The sliding unit  50  is provided with a slit  58  that extends from a first end portion to a second end portion of the sliding unit  50  in the axial direction. Note that the “slit” has a different structure from a groove that does not penetrate in that the slit penetrates the sliding unit from a first surface to a second surface in a thickness direction. The sliding unit  50  has a central sliding portion  51  provided with a plurality of accommodation concave portions  54 , in which the spiral units  61  are accommodated, an inner sliding portion  52  that is disposed on an inner side of the central sliding portion  51 , and an outer sliding portion  53  that is disposed on an outer side of the central sliding portion  51 . The central sliding portion  51  is provided with the accommodation concave portions  54 , in which the respective spiral units  61  are accommodated, and a first slit  55 , in which the tubular body  40  for guide wire is accommodated. The accommodation concave portions  54  of the central sliding portion  51  have an end portion  54   a  at a position separated by a predetermined length apart from the proximal side in a central axis direction. Each of distal ends of the spiral units  61  is brought into contact with the end portions  54   a  of the plurality of accommodation concave portions  54 , and thereby the crushing unit  60  can have a uniform diameter. In addition, the positions of the end portions  54   a  of the plurality of accommodation concave portions  54  can be each changed. Specifically, it is possible to change the predetermined length from the opening portions  54   b  of the plurality of accommodation concave portions  54  on the proximal side to the end portions  54   a  thereof on the distal side. The predetermined length from the opening portions  54   b  of the plurality of accommodation concave portions  54  on the proximal side to the end portions  54   a  thereof on the distal side can be gradually increased in an arranged order in the circumferential direction. Alternatively, it is possible to alternately change the predetermined length from the opening portions  54   b  of the plurality of accommodation concave portions  54  on the proximal side to the end portions  54   a  thereof on the distal side, thus providing the crushing unit  60  with two different diameter possibilities (even though spiral units  61  are all the same size) and two different crushing powers. In addition, the accommodation concave portions, in which the respective spiral units  61  are accommodated, may penetrate from the proximal side to the distal side in the central axis direction. In addition, the accommodation concave portions  54  are aligned in the circumferential direction of the central sliding portion  51 . The accommodation concave portion  54  has a size to the extent that the spiral unit  61  can be accommodated therein. The first slit  55  penetrates the central sliding portion  51  from the proximal side to the distal side in the axial direction. 
     The inner sliding portion  52  is disposed on the inner side of the central sliding portion  51 , and an outer peripheral surface of the inner sliding portion  52  is in contact with an inner peripheral surface of the central sliding portion  51 . The inner sliding portion  52  is provided with a second slit  56  in which the tubular body  40  for guide wire is accommodated. The second slit  56  penetrates the inner sliding portion  52  from the proximal side to the distal side in the axial direction. An inner peripheral surface of the inner sliding portion  52  slidably is in contact with the outer peripheral surface of the shaft outer tube  21 . A clearance between the inner peripheral surface of the inner sliding portion  52  and the outer peripheral surface of the shaft outer tube  21  is 0.02 mm to 0.1 mm, for example. 
     The outer sliding portion  53  is disposed on the outer side of the central sliding portion  51 , and an inner peripheral surface of the outer sliding portion  53  is in contact with an outer peripheral surface of the central sliding portion  51 . The outer sliding portion  53  is provided with a third slit  57  in which the tubular body  40  for guide wire is accommodated. The third slit  57  penetrates the outer sliding portion  53  from the proximal side to the distal side in the axial direction. 
     The central sliding portion  51 , the inner sliding portion  52 , and the outer sliding portion  53  are fixed by an adhesive or the like in a state in which the first slit  55 , the second slit  56 , and the third slit  57  are coincident (aligned) with each other, and the distal end portions of the spiral units  61  are inserted into the respective accommodation concave portions  54 . The first slit  55 , the second slit  56 , and the third slit  57  configure one slit  58 . The inner peripheral surface of the inner sliding portion  52  slidably comes into contact with the outer peripheral surface of the shaft outer tube  21 . The tubular body  40  (convex portion) for guide wire is accommodated in the slit  58  of the sliding unit  50 . Consequently, the distal portions of the spiral units  61  are fixed to the sliding unit  50  and the sliding unit  50  is slidable on the outer peripheral surface of the shaft outer tube  21 . When the shaft portion  20  rotates, a contact portion  42 , which is a part of an outer peripheral surface of the tubular body  40  for guide wire, comes into contact with an end surface  59  that forms an edge portion of the slit  58 . Consequently, relative rotation of the sliding unit  50  and the shaft portion  20  is limited. A relative rotary angle between the sliding unit  50  and the shaft portion  20  is preferably 180 degrees or smaller, more preferably 90 degrees or smaller, still more preferably 4 degrees or smaller. Hence, it is preferable that a clearance between the end surface  59  of the slit  58  and the contact portion  42  of the tubular body  40  for guide wire is set to be equal to the relative rotary angle. 
     When r 1  represents a radius from the center of the shaft outer tube  21 , which is the rotation center, to the closest outer peripheral surface (outer peripheral surface of the shaft outer tube  21 ) of the shaft portion  20 , r 2  represents a radius from the center described above to the remotest outer peripheral surface (outer peripheral surface of the tubular body  40  for guide wire) of the shaft portion  20 , and ri represents a radius to an inner peripheral surface of the sliding unit  50 , which has the smallest radius, Expression (1) set forth below is satisfied. Consequently, the rotation of the shaft portion  20  causes the shaft portion  20  to reliably come into contact with the sliding unit  50 , and thus the relative rotation of the sliding unit  50  and the shaft portion  20  is limited. 
         r 1&lt; ri&lt;r 2  Expression (1)
 
     In addition, the radius r 1  of the shaft outer tube  21  to the outer peripheral surface thereof is larger than a radius r 3  of the tubular body  40  for guide wire to the outer peripheral surface thereof. Consequently, it is possible to effectively use the tubular body  40  for guide wire, which has a smaller radius than that of the shaft outer tube  21 , as a convex portion that is fitted into the slit  58 . In addition, an outer diameter of the shaft outer tube  21  is larger than a width between opposite end surfaces  59  of the edges of the slit  58 . Consequently, it is possible to suppress deviation of the shaft outer tube  21  from the slit  58 . In addition, an outer diameter of the tubular body  40  for guide wire is smaller than a width of the slit  58 . Consequently, the tubular body  40  for guide wire can be reliably moved inside the slit  58 . 
     Constituent materials of the central sliding portion  51 , the inner sliding portion  52 , and the outer sliding portion  53  are not particularly limited as long as shapes of the portions are maintained; however, examples of materials include, preferably, stainless steel, aluminum, a polyolefin such as polyethylene or polypropylene, a polyamide, polyester such as polyethylene terephthalate, a fluoropolymer such as ETFE, PEEK, polyimide, or the like. The central sliding portion  51  may be configured of a different material from a material of the inner sliding portion  52  and the outer sliding portion  53 . For example, the inner sliding portion  52  can be configured of a fluoropolymer having a low friction coefficient so as to easily slide with respect to the shaft portion  20 , the outer sliding portion  53  can be configured of a flexible resin material such that a blood vessel is not damaged, and the central sliding portion  51  can be configured of stainless steel having high stiffness such that it is possible to reliably hold the spiral units  61 . 
     As shown in  FIG. 1 , the rotation-drive unit  70  includes a drive motor  71  and a gear portion  72  that links the drive motor  71  to the shaft outer tube  21  of the shaft portion  20 . The drive motor  71  is rotated, and thereby the shaft outer tube  21  rotates in the circumferential direction. In the exemplary embodiment, the shaft outer tube  21  is driven by the drive motor  71  so as to rotate alternately in a positive direction and a negative direction of the circumferential direction. Alternate rotation in the positive and negative directions enables bloodstream to flow alternately in opposite directions. 
     Next, a method of using the medical device  10  according to the exemplary embodiment is exemplified in a case where the thrombus in the blood vessel is crushed and aspirated. 
     Before the shaft portion  20  of the medical device  10  of the exemplary embodiment is inserted, it is desirable that a protective member such as a filter or a balloon that limits circulation of a fluid in the blood vessel is disposed on a downstream side (side to which the bloodstream flows) from the thrombus in the blood vessel. In the embodiment, as shown in  FIG. 7(A) , a filter device  110  that includes an elastic body  111  made of a wire rod that is expanded by own elastic force by being pushed out from a sheath or the like, a film-shaped filter  112  that is disposed on an outer peripheral surface of the elastic body  111 , and a wire portion  113  that is interlocked with the elastic body  111  is used. When the elastic body  111  pushed out from the sheath or the like is expanded, and the filter  112  comes into contact with the blood vessel, the filter  112  limits circulation of blood. Consequently, the crushed thrombus can be prevented from flowing in the blood vessel and moving to another position. 
     Next, the medical device  10 , which is in a state in which the distal portion of the shaft portion  20  including the crushing unit  60  is housed in the outer sheath  90 , is prepared. Next, the guide wire lumen  41  (refer to  FIG. 4 ) of the medical device  10  is inserted into a proximal end portion of the wire portion  113 . Next, the medical device  10  is caused to reach a proximal side of a thrombus  300  with the wire portion  113  as a guide. Then, when the outer sheath  90  is moved with respect to the shaft portion  20  to the proximal side, the outer sheath  90  is caused to slide with respect to the shaft portion  20  to the proximal side, the crushing unit  60  is exposed outside the outer sheath  90  and is expanded by own elastic force, as shown in  FIG. 7(B) . Here, the sliding unit  50  moves with respect to the shaft portion  20  to the proximal side. 
     Next, when the rotation-drive unit  70  (refer to  FIG. 1 ) rotates the shaft outer tube  21  in a state in which the crushing unit  60  approaches the vicinity of the thrombus  300 , the crushing unit  60  also rotates along with rotation of the shaft outer tube. In this state, when the medical device  10  is moved to the distal side, the crushing unit  60  is brought into contact with the thrombus  300 , and the crushing unit  60  crushes the thrombus  300  that is in a state of being fixed in the blood vessel. When the crushing unit  60  continues to rotate, the filter device  110  limits the flowing of the blood, and the thrombus  300  that is in a state of being fixed to the blood vessel is crushed as shown in  FIG. 8 . A crushed thrombus  301  (thrombus  300  that has been crushed into pieces) is in a floating state without being settled in the blood vessel in which the thrombus is located. 
     When the crushing unit  60  is rotated, thereby coming into contact with the thrombus  300 , the crushing unit receives a reacting force in an opposite direction to the rotation direction. A proximal portion of the crushing unit  60  is fixed to the shaft portion  20  by the interlock portion  62 . In addition, a distal portion of the crushing unit  60  is interlocked with the sliding unit  50 , and relative rotation of the sliding unit  50  with respect to the shaft portion  20  is limited. In other words, when the shaft portion  20  rotates, the contact portions  42  of the shaft portion  20  come into contact with the end surfaces  59  of the slit  58  of the sliding unit  50  (refer to  FIG. 5 ) such that the relative rotation of the sliding unit  50  with respect to the shaft portion  20  is limited. Therefore, relative rotation of the end portion on the proximal side and the end portion on the distal side of the crushing unit  60  is limited, and thus twisting of the crushing unit  60  is suppressed. After the sliding unit  50  comes into contact with the contact portions  42  of the shaft portion  20 , it is possible to rotate a second end portion (end portion on the proximal side) of the crushing unit  60  which is fixed to the shaft portion  20  and a first end portion (end portion on the distal side) of the crushing unit  60  which is fixed to the sliding unit  50 , along with rotation of the shaft portion  20 . Here, positions of the first end portion and the second end portion of the crushing unit  60  in the circumferential direction are fixed with respect to the shaft portion  20 . For example, when the spiral units  61  are twisted in a direction in which spirals of the spiral units  61  are removed (a direction in which the spiral unit has a shape approximating to a straight line without a spiral), a bulge (outer diameter) of the crushing unit  60  increases, and a range, in which it is possible to crush the thrombus, increases. In addition, when the spiral units  61  are twisted in a direction in which the spirals of the spiral units  61  are stronger (an opposite direction to the direction in which the spirals of the spiral units are removed), the bulge (outer diameter) of the crushing unit  60  decreases, and a range, in which it is possible to crush the thrombus, decreases. In particular, in a case where the thrombus is crushed while the rotating direction of the crushing unit  60  is alternately changed in the positive and negative directions, the outer diameter of the crushing unit  60  changes whenever the rotating direction changes, and the range in which it is possible to crush the thrombus changes. In the exemplary embodiment, the crushing unit  60  is unlikely to be twisted, and thereby the size of the bulge of the crushing unit  60  can be maintained. Thus, it is possible to appropriately maintain the range, in which it is possible to crush the thrombus. 
     When the crushing unit  60  moves forward or retreats in the blood vessel having an inner diameter that changes, an outer diameter of the crushing unit  60  changes along with the inner diameter of the blood vessel. Here, in order to change the outer diameter of the crushing unit  60 , the sliding unit  50  moves forward or retreats along the shaft portion  20  in the axial direction. Further, while the outer diameter of the crushing unit  60  changes depending on the movement of the sliding unit  50 , the crushing unit rotates in the circumferential direction and crushes the thrombus  300 . 
     Next, the syringe  100  (refer to  FIG. 1 ) pulls a plunger and causes the aspiration lumen  32  of the shaft inner tube  30  to be in a negative pressure state. Since the distal end portion of the shaft inner tube  30  communicates with the hollow inside of the shaft outer tube  21 , and the shaft outer tube  21  communicates with an outer portion of the shaft portion  20  through the opening portion  22 , an aspiration force is generated in the opening portion  22  with respect to an outer portion of the shaft portion  20 . Therefore, the opening portion  22  attracts the crushed thrombus  301  that floats in the blood vessel. As shown in  FIG. 9 , a part of the thrombus  301  attracted to the opening portion  22  infiltrates into the hollow inside of the shaft outer tube  21 . 
     After the plunger of the syringe  100  is pulled, the shaft inner tube  30  is moved with respect to the shaft outer tube  21  in the axial direction. When the shaft inner tube  30  is moved from a state in which the shaft inner tube  30  is closer to the proximal side than the opening portion  22  to the distal side, that is, to a side so as to approach the attachment portion  23 , of the shaft outer tube  21 , as shown in  FIG. 10 , a part of the thrombus  301  infiltrating into the hollow inside of the shaft outer tube  21  from the opening portion  22  is severed while being compressed by the distal surface of the shaft inner tube  30 . 
     When the shaft inner tube  30  is moved until the distal surface of the shaft inner tube  30  is attached to the attachment surface  23 A of the attachment portion  23 , the severed thrombus  302  is housed in the aspiration lumen  32  of the shaft inner tube  30 , as shown in  FIG. 11 . Here, a blade  31 A of the cutting portion  31  provided in the distal portion of the shaft inner tube  30  cuts a thrombus  302  into two parts. The shaft inner tube  30  is attached to the attachment surface  23 A of the attachment portion  23 , and thereby the blade  31 A is also attached to the attachment surface  23 A, and thus the severed thrombus  302  in the hollow inside of the shaft outer tube  21  is cut by the blade  31 A while the thrombus is brought into press contact with the attachment portion  23 . Therefore, it is possible to reliably cut the severed thrombus  302  and thus the size of the thrombus can be smaller than an inner diameter of the shaft inner tube  30 . Consequently, it is possible to suppress blocking by the severed thrombus  302  in the aspiration lumen  32  of the shaft inner tube  30 . 
     Since the aspiration lumen  32  of the shaft inner tube  30  is in the negative pressure state in which the syringe  100  continues to suction, as shown in  FIG. 12 , the severed thrombus  302  moves in the aspiration lumen  32  of the shaft inner tube  30  toward the proximal side. In addition, the shaft inner tube  30  is separated from the attachment portion  23  and is moved to the proximal side. In this manner, the opening portion  22  is reopened, and the thrombus  301  is aspirated and infiltrates into the hollow inside of the shaft outer tube  21 . Hence, the shaft inner tube  30  repeats reciprocating in the axial direction, and thereby it is possible to continuously aspirate the thrombus  301  while the thrombus is finely cut. 
     While the crushed thrombus  301  is aspirated into the shaft portion  20 , it is desirable that rotary motion of the shaft outer tube  21  is continued. The shaft outer tube  21  rotates, and thereby an eddy current of the blood occurs in the blood vessel, and the thrombus  301  is likely to be gathered in the vicinity of the rotating center, that is, in the vicinity of the center of the blood vessel in the radial direction. Therefore, the thrombus  301  is likely to be aspirated from the opening portion  22 . In addition, the eddy current occurring in the vicinity of the opening portion  22  also influences flowing in the aspiration lumen  32  of the shaft inner tube  30 , and swirling flow of a vortex also occurs inside the shaft inner tube  30 . Consequently, it is possible to reduce flow resistance in the axial direction inside the shaft inner tube  30  and to smoothly aspirate the cut thrombus  302 . 
     In the exemplary embodiment, the shaft outer tube  21  rotatably moves during aspiration of the thrombus  301 , and the shaft inner tube  30  reciprocates with respect to the shaft outer tube  21  in the axial direction; however, a motion other than those motions may be applied thereto. For example, a motion of the shaft inner tube  30  that rotatably moves in a relatively different motion with respect to the shaft outer tube  21  (the rotating direction is a reverse direction, or the same rotating direction but different rotating speed) is applied, and thereby it is possible to more reliably sever the thrombus  301  aspirated by the opening portion  22  and to guide the thrombus to the hollow inside of the shaft outer tube  21 . In addition, as the reciprocating motion is applied to the shaft outer tube  21 , it is possible to crush and stir the thrombus  300  in a wider range. 
     After the aspiration of the thrombus  301  is completed, the reciprocating and rotational movement of the shaft outer tube  21  and the shaft inner tube  30  are stopped. Next, the crushing unit  60  is accommodated in the outer sheath  90 , and the medical device  10  is removed from the blood vessel. Then, the filter device  110  is accommodated in the sheath or the like, it is removed from the blood vessel, and the treatment is completed. 
     As described above, according to the exemplary embodiment, the medical device  10  for crushing an object in a body lumen by being inserted into the corresponding body lumen, the device including: the elongated shaft portion  20  that is to be rotatably driven; the sliding unit  50  that is slidably interlocked with the shaft portion  20  in the axial direction of the shaft portion  20 ; and the crushing unit  60  that is provided with bendable wire rods, of which first end portions are fixed to the shaft portion  20  and second end portions are fixed to the sliding unit  50 , and is rotatable together with the shaft portion  20 . The shaft portion  20  is provided with contact portions  42  that come into contact with the sliding unit  50  during the rotation and limit relative rotation of the shaft portion  20  and the sliding unit  50 . After the sliding unit  50  is attached to the contact portions  42 , the sliding unit  50  rotates in the same direction as the shaft portion  20  along with the rotation of the shaft portion  20 . In the medical device  10  configured as described above, the shaft portion  20  rotates, and thereby the contact portions  42  of the shaft portion  20  come into contact with the sliding unit  50  such that the relative rotation of the shaft portion  20  and the sliding unit  50  is limited. Therefore, the crushing unit  60  is unlikely to be twisted even when receiving an external force in the rotating direction and is unlikely to be deformed, and thus it is possible to appropriately maintain a range in which it is possible to crush the object by the crushing unit  60 . 
     In a state in which the positions of the first end portion and the second end portion of the crushing unit  60  in the circumferential direction are fixed with respect to the shaft portion  20 , the crushing unit  60  rotates together with the shaft portion  20 . Consequently, a relative positional relationship of the first end portion and the second end portion of the crushing unit  60  does not change. Therefore, it is possible to reliably reduce twisting of the crushing unit  60  during the rotation, and it is possible to appropriately maintain the range in which it is possible to crush the object by the crushing unit  60 . 
     In addition, the sliding unit  50  is provided with the slit  58  in the axial direction of the shaft portion  20 . The shaft portion  20  is provided with the tubular body  40  (convex portion) for guide wire which is slidably fit into the slit  58 . Consequently, since the tubular body  40  for guide wire can slide in the slit  58 , it is possible to suppress the relative rotation of the sliding unit  50  and the shaft portion  20 , while the sliding unit  50  is movable along the shaft portion  20  in the axial direction. 
     In addition, the shaft portion  20  has the tubular body  40  (convex portion) for guide wire. The shaft portion  20  is provided with two lumens (the lumen  24  and the guide wire lumen  41 ) inside, and one lumen (guide wire lumen  41 ) is positioned inside the tubular body  40  for guide wire. Consequently, it is possible to use the tubular body  40  for guide wire, which has the guide wire lumen  41 , as a member that is fit into the slit  58 , and the configuration is disposed without waste such that it is possible to reduce a diameter of the device. 
     In addition, the contact portions  42  are attached to the end surfaces  59  of the edges of the slit  58 . Therefore, it is possible to highly efficiently transmit the rotating force from the contact portion  42  to the end surface  59 . 
     In addition, the radius r 3  of a part of the shaft portion  20  which is fit into the slit  58  is smaller than the radius r 1  of the shaft portion  20  that is positioned on an inner side of the sliding unit  50 . Consequently, it is possible to effectively use the part of the shaft portion  20 , which has a small radius, as a convex portion that is fit into the slit  58 . 
     In addition, the shaft portion  20  includes the shaft outer tube  21  (first tubular body) provided with the lumen  24  (first lumen) inside and the tubular body  40  (second tubular body) for guide wire which is the convex portion that is fitted into the slit  58 , which is provided with the guide wire lumen  41  (second lumen) inside, and which is adjacent with the shaft outer tube  21 . The radius r 1  of the shaft outer tube  21  to the outer peripheral surface thereof is larger than the radius r 3  of the tubular body  40  for guide wire to the outer peripheral surface thereof. Consequently, it is possible to effectively use the tubular body  40  for guide wire, which has a smaller radius than that of the shaft outer tube  21 , as the convex portion that is fitted into the slit  58 . 
     In addition, the outer diameter of the shaft outer tube  21  (first tubular body) is larger than the width between the opposite end surfaces  59  of the edges of the slit  58 , and the outer diameter of the tubular body  40  (second tubular body) for guide wire is smaller than the width of the edges of the slit  58 . The outer diameter of the shaft outer tube  21  is larger than the width of the slit  58 , and thereby it is possible to suppress deviation of the shaft outer tube  21  from the slit  58 . In addition, the outer diameter of the tubular body  40  for guide wire is smaller than the width of the slit  58 , and thereby it is possible to easily move the tubular body  40  for guide wire inside the slit  58 . 
     In addition, the disclosure also provides a treatment method for crushing the object formed in a lesion area in the body lumen by using the medical device  10  described above. The corresponding method includes a step of inserting the shaft portion  20  into the body lumen and delivering the crushing unit  60  to the lesion area and a step of rotating the crushing unit  60  by the shaft portion  20 , causing the crushing unit  60  to come into contact with the object, and crushing the corresponding object. In the exemplary treatment method configured as described above, the shaft portion  20  rotates, and thereby the contact portions  42  of the shaft portion  20  come into contact with the sliding unit  50  such that the relative rotation of the shaft portion  20  and the sliding unit  50  is limited. Therefore, the crushing unit  60  is unlikely to be twisted even when receiving an external force in the rotating direction and is unlikely to be deformed, and thus it is possible to appropriately maintain the range in which it is possible to crush the object by the crushing unit  60 . 
     Note that the disclosure is not limited to only the embodiment described above, and it is possible for those skilled in the art to perform various modifications within the technical ideas of the present invention. For example, shapes of the shaft portion and the sliding unit are not limited as long as it is possible to limit the relative rotation of the shaft portion and the sliding unit during the rotation of the shaft portion. Hence, as shown in  FIG. 13 , end surfaces  132  of a slit  131  of a sliding unit  130  (surfaces of edge portions of the slit  131 ) may have a curved surface shape (surface shape) corresponding to an outer surface of the tubular body  40  for guide wire such that the end surfaces come into surface contact with the contact portions  42  of the tubular body  40  for guide wire. Consequently, the shaft portion  20  comes into contact with the sliding unit  130  on a wide area, and thus it is possible to effectively transmit a rotational driving force. Note that the same reference signs are assigned to parts having the same functions as those of the exemplary embodiment described above, and thus the description thereof is omitted. 
     In addition, as shown in  FIG. 14 , positions of a sliding unit  140  to come into contact with the contact portions  42  of the shaft portion  20  may not be provided with the slits but may be provided with grooves  141  formed in an inner peripheral surface. Note that the same reference signs are assigned to parts having the same functions as those of the embodiment described above, and thus the description thereof is omitted. 
     In addition, as shown in  FIG. 15(A) , shapes of an outer peripheral surface of a shaft portion  150  and an inner peripheral surface of a sliding unit  160  may have an elliptic cross section that is orthogonal to the axial direction. In this manner, the outer peripheral surface of the shaft portion  150  and the inner peripheral surface of the sliding unit  160  have noncircular shapes, and thereby any part of the outer peripheral surface of the shaft portion  150  is provided with the contact portion  151  that comes into contact with the sliding unit  160  and limits relative rotation thereof. In addition, as shown in  FIG. 15(B) , shapes of an outer peripheral surface of a shaft portion  170  and an inner peripheral surface of a sliding unit  180  may have a quadrangular cross section that is orthogonal to the axial direction. In this manner, the outer peripheral surface of the shaft portion  170  and the inner peripheral surface of the sliding unit  180  have noncircular shapes, and thereby any part of the outer peripheral surface of the shaft portion  170  is provided with the contact portion  171  that comes into contact with the sliding unit  180  and limits relative rotation thereof. In addition, outer peripheral surfaces of the shaft portion and the sliding unit may have any shape as long as the shape is a noncircular shape on a cross-section that is orthogonal to the axial direction. 
     In addition, as shown in  FIG. 16 , an outer peripheral surface of a sliding unit  190  may be provided with a convex portion  191 , and an inner peripheral surface of a shaft portion  200  may be provided with a concave portion  201  into which the convex portion  191  is fitted. When the shaft portion  200  provided with the concave portion  201  rotates, the concave portion  201  is the contact portion that comes into contact with the convex portion  191  and limits relative rotation of the sliding  190  and the shaft portion  200 . 
     In addition, as shown in  FIG. 17 , the medical device may further include a film shaped cover unit  210  that is fixed to at least one part of an outer peripheral surface of the crushing unit  60 . The cover unit  210  limits flow of the blood in the blood vessel. In a configuration in which the cover unit  210  is provided, the twist of the sliding unit  50  with respect to the shaft portion  20  is suppressed, and thereby it is possible to suppress a change in diameter of the cover unit  210 . The change in diameter of the cover unit  210  is suppressed, and thereby it is possible to maintain a function of suppressing the flow by the cover unit  210 . Note that the same reference signs are assigned to parts having the same functions as those of the embodiment described above, and thus the description thereof is omitted. 
     In addition, as shown in  FIGS. 18 and 19 , a shaft portion  220  that is positioned on an inner side of the sliding unit  50  may be provided with a guide wire lumen  221 . The tubular body for guide wire may not be provided but it is possible to apply a solid member  222  as the convex portion of the slit  58 , which is in contact with the end surfaces  59 . The sliding unit  50  does not include an aspiration mechanism, and the thrombus  301  is aspirated by the outer sheath  90 . The outer sheath  90  is able to aspirate the thrombus  301  from the opening portion on the distal side to a lumen  91  inside. It is preferable that the lumen  91  has a sufficient size so as to exhibit an aspiration force even in a state in which the shaft portion  220  and the solid member  222  are accommodated inside the lumen. 
     In addition, as shown in  FIG. 20 , the shaft portion  220  that is positioned on the inner side of the sliding unit  50  may be provided with the guide wire lumen  221 , and a solid member  223 , which is the convex portion, may be provided with a spiral convex portion  224  along a circumferential surface of the shaft portion  220 . The spiral convex portion  224  is able to function as a stopper that limits movement of the sliding unit  50  to a distal direction. In addition, when the sliding unit  50  moves along the spiral convex portion  224  in the axial direction, the sliding unit rotates along the spiral convex portion  224 . When the sliding unit  50  rotates with respect to the shaft portion  220 , the outer diameter of the crushing unit  60  changes. Therefore, the sliding unit  50  is moved along the spiral convex portion  224  in the axial direction, and thereby it is possible to further expand or retract the crushing unit  60 . When the sliding unit  50  is moved along the spiral convex portion  224  in the axial direction, an elongated member  230  is inserted into the lumen  91  or the like of the outer sheath  90 . The member  230  pushes the sliding unit  50 , and thereby it is possible to move the sliding unit  50  along the spiral convex portion  224  in the axial direction. 
     In addition, as shown in  FIGS. 21 and 22 , a sliding unit  241  that is slidable with respect to a shaft portion  240  may be interlocked with the end portion of the crushing unit  60  on the proximal side thereof. Similar to the above-described exemplary embodiment, the sliding unit  241  has a C-shaped cross section that is orthogonal to the axial direction of the shaft portion  240 . A guide wire lumen is provided inside the shaft portion  240 . Each of the distal end portions of the crushing unit  60  is fixed to the shaft portion  240  at an interlock portion  242 . Here, the interlock portion  242  may not slide with respect to the shaft portion  240 . A convex portion  243  that extends in the axial direction is fixed in a range of the outer peripheral surface of the shaft portion  240 , in which the sliding unit  241  is movable. The convex portion  243  is provided with a contact portion that is able to come into contact with an end surface of a slit  244  of the sliding unit  241 . The convex portion  243  limits rotation of the sliding unit  241  with respect to the shaft portion  240 . A distal limit portion  245  having a ring shape is fixed on the distal side of the convex portion  243  on the outer peripheral surface of the shaft portion  240 . The distal limit portion  245  comes into contact with the sliding unit  241  and limits movement of the sliding unit  241  to the distal side. The movement of the sliding unit  241  to the distal side is limited, and thereby it is possible to suppress excessive expansion of the crushing unit  60 . A proximal limit portion  246  having a ring shape is fixed on the proximal side of the convex portion  243  on the outer peripheral surface of the shaft portion  240 . The proximal limit portion  246  comes into contact with the sliding unit  241  and limits movement of the sliding unit  241  to the proximal side. The movement of the sliding unit  241  to the proximal side is limited, and thereby it is possible to suppress damage to the crushing unit  60  due to stretching out of the crushing unit in the axial direction. The sliding unit  241  is fixed to a distal portion of an operating elongated body  247 . The operating elongated body  247  movably accommodates the shaft portion  240 . Hence, a part of the proximal limit portion  246  and the convex portion  243  is accommodated inside the operating elongated body  247 . In addition, the operating elongated body  247  is movably accommodated in the outer sheath  90 . An end portion of the operating elongated body  247  on the proximal side is positioned to be closer to the proximal side than the outer sheath  90 . Hence, it is possible to operate a proximal portion of the operating elongated body  247  at hand. 
     A shape of the convex portion  243  is not particularly limited as long as the sliding unit  241  is slidable. Shapes of the distal limit portion  245  and the proximal limit portion  246  are not particularly limited as long as it is possible to limit the movement of the sliding unit  241 . 
     In a state in which the crushing unit  60  is accommodated in the outer sheath  90 , the sliding unit  241  is attached to or approaches the proximal limit portion  246  as shown in  FIG. 23(A) . When the crushing unit  60  accommodated in the outer sheath  90  is expanded, the outer sheath  90  is moved with respect to the shaft portion  240  to the proximal side. Consequently, as shown in  FIG. 23(B) , the crushing unit  60  is exposed outside the outer sheath  90  and is expanded by own elastic force. Consequently, a length of the crushing unit  60  in the axial direction is shortened. Therefore, the sliding unit  241  moves with respect to the shaft portion  240  to the distal side and is attached to or approaches the distal limit portion  245 . In addition, the operating elongated body  247  also moves to the distal side along with the movement of the sliding unit  241 . The relative rotation of the sliding unit  241  with respect to the shaft portion  240  is limited by the convex portion  243 . 
     When the crushing unit  60  is accommodated in the outer sheath  90 , the position of the operating elongated body  247  at hand is fixed, and the outer sheath  90  is moved toward the distal side. When a distal end portion of the outer sheath  90  comes into contact with the crushing unit  60 , the crushing unit  60  is deformed in a distal direction and a retracting direction, as shown in  FIG. 24(A) . Hence, there is both a force for retraction in the radial direction and a force for expansion in the radial direction when the interlock portion  242  and the sliding unit  241  act on the crushing unit  60 . However, the shaft portion  240  is freely movable with respect to the operating elongated body  247  and the outer sheath  90 . Hence, the interlock portion  242  fixed to the shaft portion  240  can move away in the distal direction. Therefore, the force for expansion in the radial direction by pressing the crushing unit  60  in the axial direction does not significantly increase. Hence, by using the operating elongated body  247 , as shown in  FIG. 24(B) , it is possible to accommodate the crushing unit  60  in the outer sheath  90 . Therefore, it is possible to decrease the force acting on the medical device, and thus it is possible to suppress an occurrence of damage. When the crushing unit  60  is completely accommodated in the outer sheath  90 , the sliding unit  241  is attached to or approaches the proximal limit portion  246 . 
     Note that, when the crushing unit  60  is accommodated in the outer sheath  90 , not the position of the operating elongated body  247  but the position of the shaft portion  240  may be fixed, and the outer sheath  90  may be moved toward the distal side. In this case, the distal end portion of the outer sheath  90  comes into contact with the crushing unit  60 , and the crushing unit  60  is deformed in the distal direction and the retracting direction, as shown in  FIG. 25(A) . Unlike the case where the operating elongated body  247  is fixed, the shaft portion  240  is fixed, and thus the interlock portion  242  is not moved. Therefore, a force for pressing between the interlock portion  242  and the sliding unit  241  strongly acts on the crushing unit  60  such that the crushing unit  60  does not move away. At an early stage of the accommodation of the crushing unit  60 , a distance of a site of action (a site in which the crushing unit is in contact with the distal end portion of the outer sheath  90 ) on the interlock portion  242  is long, and an angle to the central axis of the crushing unit  60  in the site of contact is small. Consequently, an influence of no change of the position of the interlock portion  242  on the deformation of the crushing unit  60  is small. Therefore, the deformation of the crushing unit  60  due to the retraction in the radial direction is greater than the deformation of the crushing unit due to pressing in the axial direction. Hence, the crushing unit  60  is easily accommodated in the outer sheath  90 . As shown in  FIG. 25(B) , at a final stage of the accommodation, a distance of the site of action on the interlock portion  242  is short, and the angle to the central axis of the crushing unit  60  in the site of contact is large. Consequently, an influence of no change of the position of the interlock portion  242  on the deformation of the crushing unit  60  is increased. Therefore, the deformation of the crushing unit  60  due to the pressing in the axial direction is greater than the deformation of the crushing unit due to the retraction in the radial direction. Hence, in order to fix the position of the shaft portion  240  and accommodate the crushing unit  60  in the outer sheath  90 , it is necessary to use a larger force, compared to a case where the position of the operating elongated body  247  is fixed. Note that, in a case where the operating elongated body  247  is not used, the operating elongated body  247  may not be provided in the medical device. 
     As described above, the medical device includes the operating elongated body  247  that extends along the shaft portion  240  and has a distal portion which is fixed to the sliding unit  241 . Consequently, the operating elongated body  247  is operated, and thereby it is possible to control the position of the sliding unit  241 . Therefore, it is possible to freely move the interlock portion  242  fixed to the sliding unit  241 . Hence, when the crushing unit  60  is particularly accommodated, it is possible to smoothly accommodate the crushing unit  60  in the outer sheath  90 . In addition, the force acting on the medical device decreases, and thus it is possible to suppress damage to the medical device. 
     In addition, as shown in  FIG. 26 , the medical device may include a first sliding unit  251  and a second sliding unit  252  that are slidable along a shaft portion  250 . Similar to the above-described embodiment, the sliding unit  251  on the proximal side and the sliding unit  252  on the distal side have a C-shaped cross section that is orthogonal to the axial direction of the shaft portion  250 . The end portion of the crushing unit  60  on the proximal side is fixed to the proximal sliding unit  251 . The end portion of the crushing unit  60  on the distal side is fixed to the distal sliding unit  252 . 
     A proximal convex portion  253  that extends in the axial direction is fixed in a range of the outer peripheral surface of the shaft portion  250 , in which the proximal sliding unit  251  is movable. The proximal convex portion  253  is provided with a contact portion that is able to come into contact with an end surface of a slit of the proximal sliding unit  251 . The proximal convex portion  253  limits rotation of the proximal sliding unit  251  with respect to the shaft portion  250 . A first distal limit portion  254  having a ring shape is fixed on the distal side of the proximal convex portion  253  on the outer peripheral surface of the shaft portion  250 . The first distal limit portion  254  limits movement of the proximal sliding unit  251  to the distal side. The movement of the proximal sliding unit  251  to the distal side is limited, and thereby it is possible to suppress excessive expansion of the crushing unit  60 . A first proximal limit portion  255  having a ring shape is fixed on the proximal side of the proximal convex portion  253  on the outer peripheral surface of the shaft portion  250 . The first proximal limit portion  255  limits movement of the proximal sliding unit  251  to the proximal side. The movement of the proximal sliding unit  251  to the proximal side is limited, and thereby it is possible to suppress damage to the crushing unit  60  due to stretching out of the crushing unit in the axial direction. 
     A distal convex portion  256  that extends in the axial direction is fixed in a range of the outer peripheral surface of the shaft portion  250 , in which the distal sliding unit  252  is movable. The distal convex portion  256  is provided with a contact portion that is able to come into contact with an end surface of a slit of the distal sliding unit  252 . The distal convex portion  256  limits rotation of the distal sliding unit  252  with respect to the shaft portion  250 . A second distal limit portion  257  having a ring shape is fixed on the distal side of the distal convex portion  256  on the outer peripheral surface of the shaft portion  250 . The second distal limit portion  257  limits movement of the distal sliding unit  252  to the distal side. The movement of the distal sliding unit  252  to the distal side is limited, and thereby it is possible to suppress excessive expansion of the crushing unit  60 . A second proximal limit portion  258  having a ring shape is fixed on the proximal side of the distal convex portion  256  on the outer peripheral surface of the shaft portion  250 . The second proximal limit portion  258  limits movement of the distal sliding unit  252  to the proximal side. The movement of the distal sliding unit  252  to the proximal side is limited, and thereby it is possible to suppress damage to the crushing unit  60  due to stretching out of the crushing unit in the axial direction. 
     The proximal convex portion  253  and the distal convex portion  256  are different convex portions and are separated from each other in the axial direction. The proximal convex portion  253  and the distal convex portion  256  may be positioned to be coaxial or not to be coaxial with each other. Note that shapes of the proximal convex portion  253  and the distal convex portion  256  are not particularly limited as long as the proximal sliding unit  251  and the distal sliding unit  252  are slidable. Shapes of the first proximal limit portion  255  and the first distal limit portion  254  are not particularly limited as long as it is possible to limit the movement of the proximal sliding unit  251 . In addition, shapes of the second distal limit portion  257  and the second proximal limit portion  258  are not particularly limited as long as it is possible to limit the movement of the distal sliding unit  252 . 
     In a state in which the crushing unit  60  is accommodated in the outer sheath  90 , the proximal sliding unit  251  is attached to or approaches the first proximal limit portion  255  as shown in  FIG. 27(A) . In addition, the distal sliding unit  252  is attached to or approaches the second distal limit portion  257 . When the crushing unit  60  accommodated in the outer sheath  90  is expanded, the outer sheath  90  is moved with respect to the shaft portion  250  to the proximal side. Consequently, as shown in  FIG. 27(B) , the proximal sliding unit  251  is attached to the first proximal limit portion  255 , and the crushing unit  60  is gradually exposed from the outer sheath  90  and is expanded by its own elastic force. Consequently, a length of the crushing unit  60  in the axial direction is shortened. Therefore, the distal sliding unit  252  moves to the proximal side and is attached to the second proximal limit portion  258 . When the outer sheath  90  is further moved with respect to the shaft portion  250  to the proximal side, the crushing unit  60  is exposed from the outer sheath  90  and is expanded by its own elastic force, as shown in  FIG. 27(C) . Consequently, the length of the crushing unit  60  in the axial direction is shortened, the proximal sliding unit  251  moves to the distal side and is attached to the first distal limit portion  254 . Consequently, the crushing unit  60  is completely expanded. The relative rotation of the proximal sliding unit  251  and the distal sliding unit  252  with respect to the shaft portion  250  is limited by the proximal convex portion  253  and the distal convex portion  256 . 
     When the crushing unit  60  is accommodated in the outer sheath  90 , the shaft portion  250  is fixed at hand, and the outer sheath  90  is moved toward the distal side. When the distal end portion of the outer sheath  90  comes into contact with the crushing unit  60 , the crushing unit  60  is deformed in the distal direction and the retracting direction, as shown in  FIG. 28(A) . Consequently, a length of the crushing unit  60  in the axial direction is elongated. Therefore, the distal sliding unit  252  is moved to the distal side and is attached to the second distal limit portion  257 . When the distal sliding unit  252  is attached to the second distal limit portion  257 , it is not possible for the distal sliding unit  252  to move with respect to the shaft portion  250 . Therefore, a force for pressing between the distal sliding unit  252  and the proximal sliding unit  251  in the axial direction acts on the crushing unit  60 . Consequently, as shown in  FIG. 28(B) , the crushing unit  60  is completely accommodated in the outer sheath  90  while being retracted in the radial direction, and the length of crushing unit in the axial direction increases. Hence, the proximal sliding unit  251  moves to the proximal side and is attached to or approaches the first proximal limit portion  255 . 
     As described above, in the medical device, the contact portions of the proximal convex portion  253  and the distal convex portion  256 , which come into contact with the proximal sliding unit  251  and the distal sliding unit  252 , respectively, are divided in the axial direction. Consequently, a moving distance of the proximal sliding unit  251  and the distal sliding unit  252 , which move in the axial direction such that the crushing unit  60  is expanded, can be distributed into two distances. Therefore, since not one long contact portion but two short contact portions are provided, flexibility of the shaft portion  250  is improved, and the operability in the living body is improved. 
     In addition, the medical device includes the first distal limit portion  254  and the second distal limit portion  257 , which limit movement of the proximal sliding unit  251  and the distal sliding unit  252  to the distal side with respect to the shaft portion  250 , and the first proximal limit portion  255  and the second proximal limit portion  258 , which limit the movement thereof to the proximal side. Consequently, the movement of the crushing unit  60  is limited such that the crushing unit  60  can be released from the outer sheath  90  and accommodated in the outer sheath  90 . In addition, since the size of the crushing unit  60  is appropriately maintained, it is possible to reduce a burden on the living body, and it is possible to suppress the damage to the medical device. Note that, in the modification example, the two distal limit portions (the first distal limit portion  254  and the second distal limit portion  257 ), which limit the movement of the sliding units (the sliding unit  251  and the distal sliding unit  252 ) with respect to the shaft portion  250  to the distal side are provided; however, only one of the distal limit portions may be provided. In addition, in the modification example, the two proximal limit portions (the first proximal limit portion  255  and the second proximal limit portion  258 ), which limit the movement of the sliding units (the sliding unit  251  and the distal sliding unit  252 ) to the proximal side with respect to the shaft portion  250  are provided; however, only one of the proximal limit portions may be provided. 
     In addition, the body lumen, into which the medical device  10  is inserted, is not limited to the blood vessel, and examples thereof may include a vessel, a ureter, a bile duct, an oviduct, a hepatic duct, or the like. 
     In addition, the medical device may not have an aspirating function. In addition, the sliding unit may not be connected to the end portion of the crushing unit on the distal side thereof but may be interlocked with the end portion thereof on the proximal side. In addition, the shaft portion may be provided with three or more lumens or may be provided with only one lumen. In addition, the sliding unit may not need to be configured of three members (the central sliding portion  51 , the inner sliding portion  52 , and the outer sliding portion  53 ). 
     The detailed description above describes features, characteristics and operational aspects of embodiments of a medical device and treatment method representing examples of the same disclosed herein. The disclosure and the present invention are not limited, however, to the precise embodiments and variations described. Various changes, modifications and equivalents could be effected by one skilled in the art without departing from the spirit and scope of the disclosure as defined in the appended claims. It is expressly intended that all such changes, modifications and equivalents which fall within the scope of the claims are embraced by the claims.