Patent Description:
<CIT> relates to a removal element with a removal element movable between an expanded and a contracted position and a drive shaft. <CIT> relates to a catheter with a macerator, a tubular shaft and two bearing structures. In a case where a thrombus occurs in a body lumen, it is necessary to promptly remove the thrombus. An example of a symptom of the thrombus that occurs in the body lumen includes a deep vein thrombosis due to a thrombus that occurs in a vein in a deep portion of a body, such as a femoral vein or a popliteal vein. As a medical treatment method of the deep vein thrombosis, a method or the like of 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 has been known.

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 that 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 PTL <NUM>). Consequently, it is not necessary to use a medicine or possible to reduce a 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, a range, in which the wire rod is able to break the thrombus, changes.

The present invention is made in order to solve such a problem described above, and an object thereof is to provide 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 present invention by which the object described above is achieved, there is provided a medical device for crushing an object in a body lumen by being inserted into the corresponding body lumen, according to claim <NUM>.

According to the present disclosure by which the object described above is achieved, there is provided a treatment method as illustrative example not falling under the scope of the claims for crushing an object formed in a lesion area in a body lumen by using the medical device described above, the treatment method including: a step of inserting the shaft portion into the body lumen and delivering the crushing unit to the lesion area; a step of rotating the shaft portion and causing the sliding unit to be attached to the contact portion of the shaft portion; and a step of 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 example 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.

Hereinafter, an embodiment of the present invention will be described with reference to the figures. A medical device <NUM> according to the 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 objects that can be present in a body lumen. Note that a dimension 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 <FIG>, the medical device <NUM> includes a shaft portion <NUM> that is elongated and is to be rotatably driven, an outer sheath <NUM> that is able to accommodate the shaft portion <NUM>, a sliding unit <NUM> that is capable of sliding with respect to the shaft portion <NUM>, and a crushing unit <NUM> that is to be rotated by the shaft portion <NUM>. The medical device <NUM> further includes a rotation-drive unit <NUM> that rotates the shaft portion <NUM>, a hub <NUM> that is provided at a proximal end portion of the shaft portion <NUM>, and a syringe <NUM> that is connected to a proximal side of the hub <NUM>.

The shaft portion <NUM> includes a shaft outer tube <NUM> (first tubular body), a shaft inner tube <NUM>, and a tubular body <NUM> (convex portion, that is, a second tubular body) for guide wire, which each have an elongated hollow shape.

The shaft outer tube <NUM> has a distal end portion that is a distal portion of the shaft portion <NUM> and a proximal end portion that is positioned in the rotation-drive unit <NUM>. The shaft outer tube <NUM> is capable of reciprocating in a circumferential direction by the rotation-drive unit <NUM>. However, the shaft outer tube <NUM> is not limited to reciprocating and may rotate in one direction. The shaft outer tube <NUM> is provided with a lumen <NUM> (first lumen) that accommodates the shaft inner tube <NUM> inside. An inner diameter of the shaft outer tube <NUM> is larger than an outer diameter of the shaft inner tube <NUM>. The shaft outer tube <NUM> is provided with an opening portion <NUM> having a long hole shape in an axial direction in the vicinity of the distal portion such that an inside and an outside of the shaft outer tube <NUM> communicate with each other. The distal end portion of the shaft outer tube <NUM> is provided with a cylindrical attachment portion <NUM> that blocks the lumen <NUM>. A proximal surface of the attachment portion <NUM> is an attachment surface 23A that is opposite to a distal surface of the shaft inner tube <NUM>. The attachment surface 23A is positioned to be closer to a distal side than the distal end portion of the opening portion <NUM> of the shaft outer tube <NUM>. The attachment portion <NUM> is formed by stainless steel or the like.

The shaft inner tube <NUM> is coaxially housed in a hollow inside of the shaft outer tube <NUM>. The shaft inner tube <NUM> is provided with an aspiration lumen <NUM> which is in a negative pressure state such that an aspiration force is generated. The shaft inner tube <NUM> is capable of moving with respect to the shaft outer tube <NUM> in the axial direction. A distal end portion of the shaft inner tube <NUM> is positioned at a position of a proximal end portion of the opening portion <NUM> of the shaft outer tube <NUM> or is positioned to be closer to the proximal side than the position thereof. A proximal end portion of the shaft inner tube <NUM> extends to be closer to the proximal side than the proximal end portion of the shaft outer tube <NUM> and is connected to the hub <NUM>. The syringe <NUM> is connected to the hub <NUM>, thereby performing aspiration in the aspiration lumen <NUM> of the shaft inner tube <NUM>, and thus it is possible to cause the aspiration lumen <NUM> to be in the negative pressure state. A cutting portion <NUM> is provided in the aspiration lumen <NUM> in the distal end portion of the shaft inner tube <NUM>. The cutting portion <NUM> has a sharp blade 31A on the distal side, which is a thin metal plate and has a width corresponding to a diameter of the shaft inner tube <NUM>.

A distal end surface of the blade 31A and a distal end surface of the shaft inner tube <NUM> are disposed not to have a step therebetween. Therefore, when the distal surface of the shaft inner tube <NUM> is attached to the attachment surface 23A of the attachment portion <NUM>, the blade 31A is also attached to the attachment surface 23A. The shaft inner tube <NUM> is capable of reciprocating in the axial direction at least from a position of the shaft outer tube <NUM> closer to a proximal side (a position shown in <FIG>) than a proximal end of the opening portion <NUM> to a position at which the shaft inner tube is attached to the attachment surface 23A of the attachment portion <NUM>. The cutting portion <NUM> is disposed to divide a cross-sectional shape of a hollow portion of the shaft inner tube <NUM> into two portions.

The tubular body <NUM> for guide wire is disposed to be fixed to the shaft outer tube <NUM> along an outer surface of a distal portion of the shaft outer tube <NUM>. The tubular body <NUM> for guide wire is provided with a guide wire lumen <NUM> (second lumen) into which a guide wire is insertable.

It is preferable that the shaft outer tube <NUM> 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 <NUM> 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 <NUM> for guide wire is flexible. Constituent materials of the shaft outer tube <NUM>, the shaft inner tube <NUM>, and the tubular body <NUM> 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 <NUM> is able to accommodate the shaft portion <NUM> and is able to accommodate the crushing unit <NUM> while reducing a diameter of the crushing unit <NUM> interlocked with the shaft portion <NUM>. The outer sheath <NUM> is capable of sliding with respect to the shaft portion <NUM> in the axial direction.

A constituent material of the outer sheath <NUM> 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 <NUM> is provided at a distal portion of the shaft outer tube <NUM>. The crushing unit <NUM> is provided with a plurality of spiral units <NUM>. The spiral units <NUM> are all twisted in the same circumferential direction along the axial direction of the shaft outer tube <NUM>. Each of proximal end portions of the spiral units <NUM> is fixed to the shaft outer tube <NUM> at an interlock portion <NUM>. Each of distal end portions of the spiral units <NUM> is fixed to the sliding unit <NUM> that is slidable with respect to the shaft portion <NUM>. The positions at which the spiral units <NUM> are fixed to the interlock portion <NUM> and the sliding unit <NUM> are different from each other in the circumferential direction. The spiral units <NUM> 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 <NUM> in a radial direction. Consequently, the entire crushing unit <NUM> uniformly bulges in the circumferential direction. When the shaft portion <NUM> rotates, the crushing unit <NUM> 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 <NUM> constituting the crushing unit <NUM> are made of a thin metal wire having flexibility. The crushing unit <NUM> is in a state of being housed inside the outer sheath <NUM> until the shaft portion <NUM> is inserted into a target part. When the spiral units <NUM> are accommodated in the outer sheath <NUM>, the sliding unit <NUM>, with which the distal portions of the spiral units <NUM> are interlocked, is moved to the distal side along the shaft portion <NUM>. Consequently, the bulge of the spiral units <NUM> 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 <NUM>. Consequently, the spiral units <NUM> are reduced in diameter and are accommodated inside the outer sheath <NUM>. After the shaft portion <NUM> is inserted into the target part of a blood vessel, the outer sheath <NUM> is caused to slide with respect to the shaft portion <NUM> to the proximal side, and thereby the crushing unit <NUM> is exposed outside the outer sheath <NUM> and is expanded by own elastic force. Here, the sliding unit <NUM> moves along the shaft portion <NUM> to the proximal side. Therefore, it is desirable that the spiral units <NUM> are made of a shape-memory material. Examples of constituent materials of the spiral units <NUM> 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 <FIG>, <FIG>, the sliding unit <NUM> has a C-shaped cross section that is orthogonal to the axial direction of the shaft portion <NUM>. The sliding unit <NUM> is provided with a slit <NUM> that extends from a first end portion to a second end portion of the sliding unit <NUM> 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 <NUM> has a central sliding portion <NUM> provided with a plurality of accommodation concave portions <NUM>, in which the spiral units <NUM> are accommodated, an inner sliding portion <NUM> that is disposed on an inner side of the central sliding portion <NUM>, and an outer sliding portion <NUM> that is disposed on an outer side of the central sliding portion <NUM>. The central sliding portion <NUM> is provided with the accommodation concave portions <NUM>, in which the respective spiral units <NUM> are accommodated, and a first slit <NUM>, in which the tubular body <NUM> for guide wire is accommodated. The accommodation concave portions <NUM> of the central sliding portion <NUM> have an end portion 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 <NUM> is brought into contact with the end portions of the plurality of accommodation concave portions <NUM>, and thereby the crushing unit <NUM> can have a uniform diameter. In addition, the positions of the end portions of the plurality of accommodation concave portions <NUM> can be each changed. Specifically, it is possible to change the predetermined length from opening portionss of the plurality of accommodation concave portions <NUM> on the proximal side to the end portions thereof on the distal side. The predetermined length from the opening portions of the plurality of accommodation concave portions <NUM> on the proximal side to the end portions 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 of the plurality of accommodation concave portions <NUM> on the proximal side to the end portions thereof on the distal side. In addition, the accommodation concave portions, in which the respective spiral units <NUM> are accommodated, may penetrate from the proximal side to the distal side in the central axis direction. In addition, the accommodation concave portions <NUM> are aligned in the circumferential direction of the central sliding portion <NUM>. The accommodation concave portion <NUM> has a size to the extent that the spiral unit <NUM> can be accommodated therein. The first slit <NUM> penetrates the central sliding portion <NUM> from the proximal side to the distal side in the axial direction.

The inner sliding portion <NUM> is disposed on the inner side of the central sliding portion <NUM>, and an outer peripheral surface of the inner sliding portion <NUM> is in contact with an inner peripheral surface of the central sliding portion <NUM>. The inner sliding portion <NUM> is provided with a second slit <NUM> in which the tubular body <NUM> for guide wire is accommodated. The second slit <NUM> penetrates the inner sliding portion <NUM> from the proximal side to the distal side in the axial direction. An inner peripheral surface of the inner sliding portion <NUM> slidably is in contact with the outer peripheral surface of the shaft outer tube <NUM>. A clearance between the inner peripheral surface of the inner sliding portion <NUM> and the outer peripheral surface of the shaft outer tube <NUM> is <NUM> to <NUM>, for example.

The outer sliding portion <NUM> is disposed on the outer side of the central sliding portion <NUM>, and an inner peripheral surface of the outer sliding portion <NUM> is in contact with an outer peripheral surface of the central sliding portion <NUM>. The outer sliding portion <NUM> is provided with a third slit <NUM> in which the tubular body <NUM> for guide wire is accommodated. The third slit <NUM> penetrates the outer sliding portion <NUM> from the proximal side to the distal side in the axial direction.

The central sliding portion <NUM>, the inner sliding portion <NUM>, and the outer sliding portion <NUM> are fixed by an adhesive or the like in a state in which the first slit <NUM>, the second slit <NUM>, and the third slit <NUM> are coincident with each other, and the distal end portions of the spiral units <NUM> are inserted into the respective accommodation concave portions <NUM>. The first slit <NUM>, the second slit <NUM>, and the third slit <NUM> configure one slit <NUM>. The inner peripheral surface of the inner sliding portion <NUM> slidably comes into contact with the outer peripheral surface of the shaft outer tube <NUM>. The tubular body <NUM> (convex portion) for guide wire is accommodated in the slit <NUM> of the sliding unit <NUM>. Consequently, the distal portions of the spiral units <NUM> are fixed to the sliding unit <NUM> and the sliding unit <NUM> is slidable on the outer peripheral surface of the shaft outer tube <NUM>. When the shaft portion <NUM> rotates, a contact portion <NUM>, which is a part of an outer peripheral surface of the tubular body <NUM> for guide wire, comes into contact with an end surface <NUM> that forms an edge portion of the slit <NUM>. Consequently, relative rotation of the sliding unit <NUM> and the shaft portion <NUM> is limited. A relative rotary angle between the sliding unit <NUM> and the shaft portion <NUM> is preferably <NUM> degrees or smaller, more preferably <NUM> degrees or smaller, still more preferably <NUM> degrees or smaller. Hence, it is preferable that a clearance between the end surface <NUM> of the slit <NUM> and the contact portion <NUM> of the tubular body <NUM> for guide wire is set to be equal to the relative rotary angle.

When r1 represents a radius from the center of the shaft outer tube <NUM>, which is the rotation center, to the closest outer peripheral surface (outer peripheral surface of the shaft outer tube <NUM>) of the shaft portion <NUM>, r2 represents a radius from the center described above to the remotest outer peripheral surface (outer peripheral surface of the tubular body <NUM> for guide wire) of the shaft portion <NUM>, and ri represents a radius to an inner peripheral surface of the sliding unit <NUM>, which has the smallest radius, Expression (<NUM>) is satisfied. Consequently, the rotation of the shaft portion <NUM> causes the shaft portion <NUM> to reliably come into contact with the sliding unit <NUM>, and thus the relative rotation of the sliding unit <NUM> and the shaft portion <NUM> is limited.

In addition, the radius r1 of the shaft outer tube <NUM> to the outer peripheral surface thereof is larger than a radius r3 of the tubular body <NUM> for guide wire to the outer peripheral surface thereof. Consequently, it is possible to effectively use the tubular body <NUM> for guide wire, which has a smaller radius than that of the shaft outer tube <NUM>, as a convex portion that is fitted into the slit <NUM>. In addition, an outer diameter of the shaft outer tube <NUM> is larger than a width between opposite end surfaces <NUM> of edges of the slit <NUM>. Consequently, it is possible to suppress deviation of the shaft outer tube <NUM> from the slit <NUM>. In addition, an outer diameter of the tubular body <NUM> for guide wire is smaller than a width of the slit <NUM>. Consequently, the tubular body <NUM> for guide wire can be reliably moved inside the slit <NUM>.

Constituent materials of the central sliding portion <NUM>, the inner sliding portion <NUM>, and the outer sliding portion <NUM> 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 <NUM> may be configured of a different material from a material of the inner sliding portion <NUM> and the outer sliding portion <NUM>. For example, the inner sliding portion <NUM> can be configured of a fluoropolymer having a low friction coefficient so as to easily slide with respect to the shaft portion <NUM>, the outer sliding portion <NUM> can be configured of a flexible resin material such that a blood vessel is not damaged, and the central sliding portion <NUM> can be configured of stainless steel having high stiffness such that it is possible to reliably hold the spiral units <NUM>.

As shown in <FIG>, the rotation-drive unit <NUM> includes a drive motor <NUM> and a gear portion <NUM> that links the drive motor <NUM> to the shaft outer tube <NUM> of the shaft portion <NUM>. The drive motor <NUM> is rotated, and thereby the shaft outer tube <NUM> rotates in the circumferential direction. In the embodiment, the shaft outer tube <NUM> is driven by the drive motor <NUM> so as to rotate alternately in two positive and negative directions of the circumferential direction. Alternate rotation in the two positive and negative directions enables bloodstream to flow alternately in opposite directions.

Next, an example method of using the medical device <NUM> according to the embodiment is exemplified in a case where the thrombus in the blood vessel is crushed and aspirated.

Before the shaft portion <NUM> of the medical device <NUM> of the 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>, a filter device <NUM> that includes an elastic body <NUM> 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 <NUM> that is disposed on an outer peripheral surface of the elastic body <NUM>, and a wire portion <NUM> that is interlocked with the elastic body <NUM> is used. When the elastic body <NUM> pushed out from the sheath or the like is expanded, and the filter <NUM> comes into contact with the blood vessel, the filter <NUM> 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 <NUM>, which is in a state in which the distal portion of the shaft portion <NUM> including the crushing unit <NUM> is housed in the outer sheath <NUM>, is prepared. Next, the guide wire lumen <NUM> (refer to <FIG>) of the medical device <NUM> is inserted into a proximal end portion of the wire portion <NUM>. Next, the medical device <NUM> is caused to reach a proximal side of a thrombus <NUM> with the wire portion <NUM> as a guide. Then, when the outer sheath is moved with respect to the shaft portion <NUM> to the proximal side, the outer sheath <NUM> is caused to slide with respect to the shaft portion <NUM> to the proximal side, the crushing unit <NUM> is exposed outside the outer sheath <NUM> and is expanded by own elastic force, as shown in <FIG>. Here, the sliding unit <NUM> moves with respect to the shaft portion <NUM> to the proximal side.

Next, when the rotation-drive unit <NUM> (refer to <FIG>) rotates the shaft outer tube <NUM> in a state in which the crushing unit <NUM> approaches the vicinity of the thrombus <NUM>, the crushing unit <NUM> also rotates along with rotation of the shaft outer tube. In this state, when the medical device <NUM> is moved to the distal side, the crushing unit <NUM> is brought into contact with the thrombus <NUM>, and the crushing unit <NUM> crushes the thrombus <NUM> that is in a state of being fixed in the blood vessel. When the crushing unit <NUM> continues to rotate, the filter device <NUM> limits the flowing of the blood, and the thrombus <NUM> that is in a state of being fixed to the blood vessel is crushed as shown in <FIG>. A crushed thrombus <NUM> is in a floating state without being settled in the blood vessel in which the thrombus stays.

When the crushing unit <NUM> is rotated, thereby coming into contact with the thrombus <NUM>, the crushing unit receives a reacting force in an opposite direction to the rotation direction. A proximal portion of the crushing unit <NUM> is fixed to the shaft portion <NUM> by the interlock portion <NUM>. In addition, a distal portion of the crushing unit <NUM> is interlocked with the sliding unit <NUM>, and relative rotation of the sliding unit <NUM> with respect to the shaft portion <NUM> is limited. In other words, when the shaft portion <NUM> rotates, the contact portions <NUM> of the shaft portion <NUM> come into contact with the end surfaces <NUM> of the slit <NUM> of the sliding unit <NUM> (refer to <FIG>) such that the relative rotation of the sliding unit <NUM> with respect to the shaft portion <NUM> 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 <NUM> is limited, and thus twisting is suppressed. After the sliding unit <NUM> comes into contact with the contact portions <NUM> of the shaft portion <NUM>, it is possible to rotate a second end portion (end portion on the proximal side) of the crushing unit <NUM> which is fixed to the shaft portion <NUM> and a first end portion (end portion on the distal side) of the crushing unit <NUM> which is fixed to the sliding unit <NUM>, along with rotation of the shaft portion <NUM>. Here, positions of the first end portion and the second end portion of the crushing unit <NUM> in the circumferential direction are fixed with respect to the shaft portion <NUM>. For example, when the spiral units <NUM> are twisted in a direction in which spirals of the spiral units <NUM> 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 <NUM> increases, and a range, in which it is possible to crush the thrombus, increases. In addition, when the spiral units <NUM> are twisted in a direction in which the spirals of the spiral units <NUM> 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 <NUM> 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 <NUM> is changed in both of the positive and negative directions alternately, the outer diameter of the crushing unit <NUM> changes whenever the rotating direction changes, and the range in which it is possible to crush the thrombus changes. By comparison, in the embodiment, the crushing unit <NUM> is unlikely to be twisted, and thereby the size of the bulge of the crushing unit <NUM> 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 <NUM> moves forward or retreats in the blood vessel having an inner diameter that changes, an outer diameter of the crushing unit <NUM> changes along with the inner diameter of the blood vessel. Here, in order to change the outer diameter of the crushing unit <NUM>, the sliding unit <NUM> moves forward or retreats along the shaft portion <NUM> in the axial direction. Further, while the outer diameter of the crushing unit <NUM> changes depending on the movement of the sliding unit <NUM>, the crushing unit rotates in the circumferential direction and crushes the thrombus <NUM>.

Next, the syringe <NUM> (refer to <FIG>) pulls a plunger and causes the aspiration lumen <NUM> of the shaft inner tube <NUM> to be in a negative pressure state. Since the distal end portion of the shaft inner tube <NUM> communicates with the hollow inside of the shaft outer tube <NUM>, and the shaft outer tube <NUM> communicates with an outer portion of the shaft portion <NUM> through the opening portion <NUM>, an aspiration force is generated in the opening portion <NUM> with respect to an outer portion of the shaft portion <NUM>. Therefore, the opening portion <NUM> attracts the crushed thrombus <NUM> that floats in the blood vessel. As shown in <FIG>, a part of the thrombus <NUM> attracted to the opening portion <NUM> infiltrates into the hollow inside of the shaft outer tube <NUM>.

After the plunger of the syringe <NUM> is pulled, the shaft inner tube <NUM> is moved with respect to the shaft outer tube <NUM> in the axial direction. When the shaft inner tube <NUM> is moved from a state in which the shaft inner tube <NUM> is placed to be closer to the proximal side than the opening portion <NUM> to the distal side, that is, to a side so as to approach the attachment portion <NUM>, of the shaft outer tube <NUM>, as shown in <FIG>, a part of the thrombus <NUM> infiltrating into the hollow inside of the shaft outer tube <NUM> from the opening portion <NUM> is severed while being compressed by the distal surface of the shaft inner tube <NUM>.

When the shaft inner tube <NUM> is moved until the distal surface of the shaft inner tube <NUM> is attached to the attachment surface 23A of the attachment portion <NUM>, the severed thrombus <NUM> is housed in the aspiration lumen <NUM> of the shaft inner tube <NUM>, as shown in <FIG>. Here, a blade 31A of the cutting portion <NUM> provided in the distal portion of the shaft inner tube <NUM> cuts a thrombus <NUM> into two parts. The shaft inner tube <NUM> is attached to the attachment surface 23A of the attachment portion <NUM>, and thereby the blade 31A is also attached to the attachment surface 23A, and thus the severed thrombus <NUM> in the hollow inside of the shaft outer tube <NUM> is cut by the blade 31A while the thrombus is brought into press contact with the attachment portion <NUM>. Therefore, it is possible to reliably cut the severed thrombus <NUM> and thus the side of the thrombus can be smaller than an inner diameter of the shaft inner tube <NUM>. Consequently, it is possible to suppress blocking of the severed thrombus <NUM> in the aspiration lumen <NUM> of the shaft inner tube <NUM>.

Since the aspiration lumen <NUM> of the shaft inner tube <NUM> is in the negative pressure state in which the syringe <NUM> continues to aspire, as shown in <FIG>, and the severed thrombus <NUM> moves in the aspiration lumen <NUM> of the shaft inner tube <NUM> toward the proximal side. In addition, the shaft inner tube <NUM> is separated from the attachment portion <NUM> and is moved to the proximal side. In this manner, the opening portion <NUM> is reopened, and the thrombus <NUM> is aspirated and infiltrates into the hollow inside of the shaft outer tube <NUM>. Hence, the shaft inner tube <NUM> repeats reciprocating in the axial direction, and thereby it is possible to continuously aspirate the thrombus <NUM> while the thrombus is finely cut.

While the crushed thrombus <NUM> is aspirated into the shaft portion <NUM>, it is desirable that rotary motion of the shaft outer tube <NUM> is continued. The shaft outer tube <NUM> rotates, and thereby an eddy current of the blood occurs in the blood vessel, and the thrombus <NUM> 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 <NUM> is likely to be aspirated from the opening portion <NUM>. In addition, the eddy current occurring in the vicinity of the opening portion <NUM> also influences flowing in the aspiration lumen <NUM> of the shaft inner tube <NUM>, and swirling flow of a vortex also occurs inside the shaft inner tube <NUM>. Consequently, it is possible to reduce flow resistance in the axial direction inside the shaft inner tube <NUM> and to smoothly aspirate the cut thrombus <NUM>.

In the embodiment, the shaft outer tube <NUM> rotatably moves during aspiration of the thrombus <NUM>, and the shaft inner tube <NUM> reciprocates with respect to the shaft outer tube <NUM> in the axial direction; however, a motion other than those motions may be applied thereto. For example, a motion of the shaft inner tube <NUM> that rotatably moves in a relatively different motion with respect to the shaft outer tube <NUM> (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 <NUM> aspirated by the opening portion <NUM> and to guide the thrombus to the hollow inside of the shaft outer tube <NUM>. In addition, the reciprocating motion is applied to the shaft outer tube <NUM>, it is possible to crush and stir the thrombus <NUM> in a wider range.

After the aspiration of the thrombus <NUM> is completed, the reciprocating and rotational movement of the shaft outer tube <NUM> and the shaft inner tube <NUM> are stopped. Next, the crushing unit <NUM> is accommodated in the outer sheath <NUM>, and the medical device <NUM> is removed from the blood vessel. Then, the filter device <NUM> is accommodated in the sheath or the like, is removed from the blood vessel, and the treatment is completed.

As described above, according to the embodiment, the medical device <NUM> for crushing an object in a body lumen by being inserted into the corresponding body lumen, the device including: the elongated shaft portion <NUM> that is to be rotatably driven; the sliding unit <NUM> that is slidably interlocked with the shaft portion <NUM> in the axial direction of the shaft portion <NUM>; and the crushing unit <NUM> that is provided with bendable wire rods, of which first end portions are fixed to the shaft portion <NUM> and second end portions are fixed to the sliding unit <NUM>, and is rotatable together with the shaft portion <NUM>. The shaft portion <NUM> is provided with contact portions <NUM> that are to come into contact with the sliding unit <NUM> during the rotation and are to limit relative rotation of the shaft portion <NUM> and the sliding unit <NUM>. After the sliding unit <NUM> is attached to the contact portions <NUM>, the sliding unit <NUM> rotates in the same direction as the shaft portion <NUM> along with the rotation of the shaft portion <NUM>. In the medical device <NUM> configured as described above, the shaft portion <NUM> rotates, and thereby the contact portions <NUM> of the shaft portion <NUM> come into contact with the sliding unit <NUM> such that the relative rotation of the shaft portion <NUM> and the sliding unit <NUM> is limited. Therefore, the crushing unit <NUM> 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 <NUM>.

In a state in which the positions of the first end portion and the second end portion of the crushing unit <NUM> in the circumferential direction are fixed with respect to the shaft portion <NUM>, the crushing unit <NUM> rotates together with the shaft portion <NUM>. Consequently, a relative positional relationship of the first end portion and the second end portion of the crushing unit <NUM> does not change. Therefore, it is possible to reliably reduce twisting of the crushing unit <NUM> 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 <NUM>.

In addition, the sliding unit <NUM> is provided with the slit <NUM> in the axial direction of the shaft portion <NUM>. The shaft portion <NUM> is provided with the tubular body <NUM> (convex portion) for guide wire which is slidably fitted into the slit <NUM>. Consequently, since the tubular body <NUM> for guide wire can slide in the slit <NUM>, it is possible to suppress the relative rotation of the sliding unit <NUM> and the shaft portion <NUM>, while the sliding unit <NUM> is movable along the shaft portion <NUM> in the axial direction.

In addition, the shaft portion <NUM> has the tubular body <NUM> (convex portion) for guide wire. The shaft portion <NUM> is provided with two lumens (the lumen <NUM> and the guide wire lumen <NUM>) inside, and one lumen (guide wire lumen <NUM>) is positioned inside the tubular body <NUM> for guide wire. Consequently, it is possible to use the tubular body <NUM> for guide wire, which has the guide wire lumen <NUM>, as a member that is fitted into the slit <NUM>, and the configuration is disposed without waste such that it is possible to reduce a diameter of the device.

In addition, the contact portions <NUM> are attached to the end surfaces <NUM> of the edges of the slit <NUM>. Therefore, it is possible to highly efficiently transmit the rotating force from the contact portion <NUM> to the end surface <NUM>.

In addition, the radius r3 of a part of the shaft portion <NUM> which is fitted into the slit <NUM> is smaller than the radius r1 of the shaft portion <NUM> that positioned on an inner side of the sliding unit <NUM>. Consequently, it is possible to effectively use the part of the shaft portion <NUM>, which has a small radius, as a convex portion that is fitted into the slit <NUM>.

In addition, the shaft portion <NUM> includes the shaft outer tube <NUM> (first tubular body) provided with the lumen <NUM> (first lumen) inside and the tubular body <NUM> (second tubular body) for guide wire which is the convex portion that is fitted into the slit <NUM>, which is provided with the guide wire lumen <NUM> (second lumen) inside, and which is adjacent with the shaft outer tube <NUM>. The radius r1 of the shaft outer tube <NUM> to the outer peripheral surface thereof is larger than the radius r3 of the tubular body <NUM> for guide wire to the outer peripheral surface thereof. Consequently, it is possible to effectively use the tubular body <NUM> for guide wire, which has a smaller radius than that of the shaft outer tube <NUM>, as the convex portion that is fitted into the slit <NUM>.

In addition, the outer diameter of the shaft outer tube <NUM> (first tubular body) is larger than the width between the opposite end surfaces <NUM> of the edges of the slit <NUM>, and the outer diameter of the tubular body <NUM> (second tubular body) for guide wire is smaller than the width of the edges of the slit <NUM>. The outer diameter of the shaft outer tube <NUM> is larger than the width of the slit <NUM>, and thereby it is possible to suppress deviation of the shaft outer tube <NUM> from the slit <NUM>. In addition, the outer diameter of the tubular body <NUM> for guide wire is smaller than the width of the slit <NUM>, and thereby it is possible to well move the tubular body <NUM> for guide wire inside the slit <NUM>.

In addition, the illustrative example not falling under the scope of the claims also provides a treatment method for crushing the object formed in a lesion area in the body lumen by using the medical device <NUM> described above. The corresponding method includes a step of inserting the shaft portion <NUM> into the body lumen and delivering the crushing unit <NUM> to the lesion area and a step of rotating the crushing unit <NUM> by the shaft portion <NUM>, causing the crushing unit <NUM> to come into contact with the object, and crushing the corresponding object. In the treatment method configured as described above, the shaft portion <NUM> rotates, and thereby the contact portions <NUM> of the shaft portion <NUM> come into contact with the sliding unit <NUM> such that the relative rotation of the shaft portion <NUM> and the sliding unit <NUM> is limited. Therefore, the crushing unit <NUM> 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 <NUM>.

Note that the present invention 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 scope of the claims. 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>, end surfaces <NUM> of a slit <NUM> of a sliding unit <NUM> (surfaces of edge portions of the slit <NUM>) may have a curved surface shape (surface shape) corresponding to an outer surface of the tubular body <NUM> for guide wire such that the end surfaces come into surface contact with the contact portions <NUM> of the tubular body <NUM> for guide wire. Consequently, the shaft portion <NUM> comes into contact with the sliding unit <NUM> 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 embodiment described above, and thus the description thereof is omitted.

In addition, as shown in <FIG>, positions of a sliding unit <NUM> to come into contact with the contact portions <NUM> of the shaft portion <NUM> may not be provided with the slits but may be provided with grooves <NUM> 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>, shapes of an outer peripheral surface of a shaft portion <NUM> and an inner peripheral surface of a sliding unit <NUM> may have an elliptic cross section that is orthogonal to the axial direction. In this manner, the outer peripheral surface of the shaft portion <NUM> and the inner peripheral surface of the sliding unit <NUM> have noncircular shapes, and thereby any part of the outer peripheral surface of the shaft portion <NUM> is provided with the contact portion <NUM> that comes into contact with the sliding unit <NUM> and limits relative rotation thereof. In addition, as shown in <FIG>, shapes of an outer peripheral surface of a shaft portion <NUM> and an inner peripheral surface of a sliding unit <NUM> may have a quadrangular cross section that is orthogonal to the axial direction. In this manner, the outer peripheral surface of the shaft portion <NUM> and the inner peripheral surface of the sliding unit <NUM> have noncircular shapes, and thereby any part of the outer peripheral surface of the shaft portion <NUM> is provided with the contact portion <NUM> that comes into contact with the sliding unit <NUM> 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>, an outer peripheral surface of a sliding unit <NUM> may be provided with a convex portion <NUM>, and an inner peripheral surface of a shaft portion <NUM> may be provided with a concave portion <NUM> into which the convex portion <NUM> is fitted. When the shaft portion <NUM> provided with the concave portion <NUM> rotates, the concave portion <NUM> is the contact portion that comes into contact with the convex portion <NUM> and limits relative rotation of the sliding <NUM> and the shaft portion <NUM>.

In addition, as shown in <FIG>, the medical device may further include a film shaped cover unit <NUM> that is fixed to at least one part of an outer peripheral surface of the crushing unit <NUM>. The cover unit <NUM> limits flow of the blood in the blood vessel. In a configuration in which the cover unit <NUM> is provided, the twist of the sliding unit <NUM> with respect to the shaft portion <NUM> is suppressed, and thereby it is possible to suppress a change in diameter of the cover unit <NUM>. The change in diameter of the cover unit <NUM> is suppressed, and thereby it is possible to well maintain a function of suppressing the flow by the cover unit <NUM>. 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> and <FIG>, a shaft portion <NUM> that is positioned on an inner side of the sliding unit <NUM> may be provided with a guide wire lumen <NUM>. The tubular body for guide wire may not be provided but it is possible to apply a solid member <NUM> as the convex portion of the slit <NUM>, which is in contact with the end surfaces <NUM>. The sliding unit <NUM> does not include an aspiration mechanism, and the thrombus <NUM> is aspirated by the outer sheath <NUM>. The outer sheath <NUM> is able to aspirate the thrombus <NUM> from the opening portion on the distal side to a lumen <NUM> inside. It is preferable that the lumen <NUM> has a sufficient size so as to exhibit an aspiration force even in a state in which the shaft portion <NUM> and the solid member <NUM> are accommodated inside the lumen.

In addition, as shown in <FIG>, the shaft portion <NUM> that is positioned on the inner side of the sliding unit <NUM> may be provided with the guide wire lumen <NUM>, and a solid member <NUM>, which is the convex portion, may be provided with a spiral convex portion <NUM> along a circumferential surface of the shaft portion <NUM>. The spiral convex portion <NUM> is able to function as a stopper that limits movement of the sliding unit <NUM> to a distal direction. In addition, when the sliding unit <NUM> moves along the spiral convex portion <NUM> in the axial direction, the sliding unit rotates along the spiral convex portion <NUM>. When the sliding unit <NUM> rotates with respect to the shaft portion <NUM>, the outer diameter of the crushing unit <NUM> changes. Therefore, the sliding unit <NUM> is moved along the spiral convex portion <NUM> in the axial direction, and thereby it is possible to further expand or retract the crushing unit <NUM>. When the sliding unit <NUM> is moved along the spiral convex portion <NUM> in the axial direction, an elongated member <NUM> is inserted into the lumen <NUM> or the like of the outer sheath <NUM>. The member <NUM> pushes the sliding unit <NUM>, and thereby it is possible to move the sliding unit <NUM> along the spiral convex portion <NUM> in the axial direction.

In addition, as shown in <FIG>, a sliding unit <NUM> that is slidable with respect to a shaft portion <NUM> may be interlocked with the end portion of the crushing unit <NUM> on the proximal side thereof. Similar to the above-described embodiment, the sliding unit <NUM> has a C-shaped cross section that is orthogonal to the axial direction of the shaft portion <NUM>. A guide wire lumen is provided inside the shaft portion <NUM>. Each of the distal end portions of the crushing unit <NUM> is fixed to the shaft portion <NUM> at an interlock portion <NUM>. Here, the interlock portion <NUM> may not slide with respect to the shaft portion <NUM>. A convex portion <NUM> that extends in the axial direction is fixed in a range of the outer peripheral surface of the shaft portion <NUM>, in which the sliding unit <NUM> is movable. The convex portion <NUM> is provided with a contact portion that is able to come into contact with an end surface of a slit <NUM> of the sliding unit <NUM>. The convex portion <NUM> limits rotation of the sliding unit <NUM> with respect to the shaft portion <NUM>. A distal limit portion <NUM> having a ring shape is fixed on the distal side of the convex portion <NUM> on the outer peripheral surface of the shaft portion <NUM>. The distal limit portion <NUM> comes into contact with the sliding unit <NUM> and limits movement of the sliding unit <NUM> to the distal side. The movement of the sliding unit <NUM> to the distal side is limited, and thereby it is possible to suppress excessive expansion of the crushing unit <NUM>. A proximal limit portion <NUM> having a ring shape is fixed on the proximal side of the convex portion <NUM> on the outer peripheral surface of the shaft portion <NUM>. The proximal limit portion <NUM> comes into contact with the sliding unit <NUM> and limits movement of the sliding unit <NUM> to the proximal side. The movement of the sliding unit <NUM> to the proximal side is limited, and thereby it is possible to suppress damage to the crushing unit <NUM> due to stretching out of the crushing unit in the axial direction. The sliding unit <NUM> is fixed to a distal portion of an operating elongated body <NUM>. The operating elongated body <NUM> movably accommodates the shaft portion <NUM>. Hence, a part of the proximal limit portion <NUM> and the convex portion <NUM> is accommodated inside the operating elongated body <NUM>. In addition, the operating elongated body <NUM> is movably accommodated in the outer sheath <NUM>. An end portion of the operating elongated body <NUM> on the proximal side is positioned to be closer to the proximal side than the outer sheath <NUM>. Hence, it is possible to operate a proximal portion of the operating elongated body <NUM> at hand.

A shape of the convex portion <NUM> is not particularly limited as long as the sliding unit <NUM> is slidable. Shapes of the distal limit portion <NUM> and the proximal limit portion <NUM> are not particularly limited as long as it is possible to limit the movement of the sliding unit <NUM>.

In a state in which the crushing unit <NUM> is accommodated in the outer sheath <NUM>, the sliding unit <NUM> is attached to or approaches the proximal limit portion <NUM> as shown in <FIG>. When the crushing unit <NUM> accommodated in the outer sheath <NUM> is expanded, the outer sheath <NUM> is moved with respect to the shaft portion <NUM> to the proximal side. Consequently, as shown in <FIG>, the crushing unit <NUM> is exposed outside the outer sheath <NUM> and is expanded by own elastic force. Consequently, a length of the crushing unit <NUM> in the axial direction is shortened. Therefore, the sliding unit <NUM> moves with respect to the shaft portion <NUM> to the distal side and is attached to or approaches the distal limit portion <NUM>. In addition, the operating elongated body <NUM> also moves to the distal side along with the movement of the sliding unit <NUM>. The relative rotation of the sliding unit <NUM> with respect to the shaft portion <NUM> is limited by the convex portion <NUM>.

When the crushing unit <NUM> is accommodated in the outer sheath <NUM>, the position of the operating elongated body <NUM> at hand is fixed, and the outer sheath <NUM> is moved toward the distal side. When a distal end portion of the outer sheath <NUM> comes into contact with the crushing unit <NUM>, the crushing unit <NUM> is deformed in a distal direction and a retracting direction, as shown in <FIG>. Hence, when both of a force for retraction in the radial direction and a force for expansion in the radial direction by pressing the interlock portion <NUM> and the sliding unit <NUM> act on the crushing unit <NUM>. However, the shaft portion <NUM> is freely movable with respect to the operating elongated body <NUM> and the outer sheath <NUM>. Hence, the interlock portion <NUM> fixed to the shaft portion <NUM> can move away in the distal direction. Therefore, the force for expansion in the radial direction by pressing the crushing unit <NUM> in the axial direction does not too much increase. Hence, by using the operating elongated body <NUM>, as shown in <FIG>, it is possible to accommodate the crushing unit <NUM> in the outer sheath <NUM>. 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 <NUM> is completely accommodated in the outer sheath <NUM>, the sliding unit <NUM> is attached to or approaches the proximal limit portion <NUM>.

Note that, when the crushing unit <NUM> is accommodated in the outer sheath <NUM>, not the position of the operating elongated body <NUM> but the position of the shaft portion <NUM> may be fixed, and the outer sheath <NUM> may be moved toward the distal side. In this case, the distal end portion of the outer sheath <NUM> comes into contact with the crushing unit <NUM>, and the crushing unit <NUM> is deformed in the distal direction and the retracting direction, as shown in <FIG>. Unlike the case where the operating elongated body <NUM> is fixed, the shaft portion <NUM> is fixed, and thus the interlock portion <NUM> is not moved. Therefore, a force for pressing between the interlock portion <NUM> and the sliding unit <NUM> strongly acts on the crushing unit <NUM> such that the crushing unit <NUM> does not move away. At an early stage of the accommodation of the crushing unit <NUM>, 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 <NUM>) on the interlock portion <NUM> is long, and an angle to the central axis of the crushing unit <NUM> in the site of contact is small. Consequently, an influence of no change of the position of the interlock portion <NUM> on the deformation of the crushing unit <NUM> is small. Therefore, the deformation of the crushing unit <NUM> 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 <NUM> is easily accommodated in the outer sheath <NUM>. As shown in <FIG>, at a final stage of the accommodation, a distance of the site of action on the interlock portion <NUM> is short, and the angle to the central axis of the crushing unit <NUM> in the site of contact is large. Consequently, an influence of no change of the position of the interlock portion <NUM> on the deformation of the crushing unit <NUM> is increased. Therefore, the deformation of the crushing unit <NUM> 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 <NUM> and accommodate the crushing unit <NUM> in the outer sheath <NUM>, it is necessary to use a larger force, compared to a case where the position of the operating elongated body <NUM> is fixed. Note that, in a case where the operating elongated body <NUM> is not used, the operating elongated body <NUM> may not be provided in the medical device.

As described above, the medical device includes the operating elongated body <NUM> that extends along the shaft portion <NUM> and has a distal portion which is fixed to the sliding unit <NUM>. Consequently, the operating elongated body <NUM> is operated, and thereby it is possible to control the position of the sliding unit <NUM>. Therefore, it is possible to freely move the interlock portion <NUM> fixed to the sliding unit <NUM>. Hence, when the crushing unit <NUM> is particularly accommodated, it is possible to smoothly accommodate the crushing unit <NUM> in the outer sheath <NUM>. 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>, the medical device may include a first sliding unit <NUM> and a second sliding unit <NUM> that are slidable along a shaft portion <NUM>. Similar to the above-described embodiment, the sliding unit <NUM> on the proximal side and the sliding unit <NUM> on the distal side have a C-shaped cross section that is orthogonal to the axial direction of the shaft portion <NUM>. The end portion of the crushing unit <NUM> on the proximal side is fixed to the proximal sliding unit <NUM>. The end portion of the crushing unit <NUM> on the distal side is fixed to the distal sliding unit <NUM>.

A proximal convex portion <NUM> that extends in the axial direction is fixed in a range of the outer peripheral surface of the shaft portion <NUM>, in which the proximal sliding unit <NUM> is movable. The proximal convex portion <NUM> 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 <NUM>. The proximal convex portion <NUM> limits rotation of the proximal sliding unit <NUM> with respect to the shaft portion <NUM>. A first distal limit portion <NUM> having a ring shape is fixed on the distal side of the proximal convex portion <NUM> on the outer peripheral surface of the shaft portion <NUM>. The first distal limit portion <NUM> limits movement of the proximal sliding unit <NUM> to the distal side. The movement of the proximal sliding unit <NUM> to the distal side is limited, and thereby it is possible to suppress excessive expansion of the crushing unit <NUM>. A first proximal limit portion <NUM> having a ring shape is fixed on the proximal side of the proximal convex portion <NUM> on the outer peripheral surface of the shaft portion <NUM>. The first proximal limit portion <NUM> limits movement of the proximal sliding unit <NUM> to the proximal side. The movement of the proximal sliding unit <NUM> to the proximal side is limited, and thereby it is possible to suppress damage to the crushing unit <NUM> due to stretching out of the crushing unit in the axial direction.

A distal convex portion <NUM> that extends in the axial direction is fixed in a range of the outer peripheral surface of the shaft portion <NUM>, in which the distal sliding unit <NUM> is movable. The distal convex portion <NUM> 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 <NUM>. The distal convex portion <NUM> limits rotation of the distal sliding unit <NUM> with respect to the shaft portion <NUM>. A second distal limit portion <NUM> having a ring shape is fixed on the distal side of the distal convex portion <NUM> on the outer peripheral surface of the shaft portion <NUM>. The second distal limit portion <NUM> limits movement of the distal sliding unit <NUM> to the distal side. The movement of the distal sliding unit <NUM> to the distal side is limited, and thereby it is possible to suppress excessive expansion of the crushing unit <NUM>. A second proximal limit portion <NUM> having a ring shape is fixed on the proximal side of the distal convex portion <NUM> on the outer peripheral surface of the shaft portion <NUM>. The second proximal limit portion <NUM> limits movement of the distal sliding unit <NUM> to the proximal side. The movement of the distal sliding unit <NUM> to the proximal side is limited, and thereby it is possible to suppress damage to the crushing unit <NUM> due to stretching out of the crushing unit in the axial direction.

The proximal convex portion <NUM> and the distal convex portion <NUM> are different convex portions and are separated from each other in the axial direction. The proximal convex portion <NUM> and the distal convex portion <NUM> may be positioned to be coaxial or not to be coaxial with each other. Note that shapes of the proximal convex portion <NUM> and the distal convex portion <NUM> are not particularly limited as long as the proximal sliding unit <NUM> and the distal sliding unit <NUM> are slidable. Shapes of the first proximal limit portion <NUM> and the first distal limit portion <NUM> are not particularly limited as long as it is possible to limit the movement of the proximal sliding unit <NUM>. In addition, shapes of the second distal limit portion <NUM> and the second proximal limit portion <NUM> are not particularly limited as long as it is possible to limit the movement of the distal sliding unit <NUM>.

In a state in which the crushing unit <NUM> is accommodated in the outer sheath <NUM>, the proximal sliding unit <NUM> is attached to or approaches the first proximal limit portion <NUM> as shown in <FIG>. In addition, the distal sliding unit <NUM> is attached to or approaches the second distal limit portion <NUM>. When the crushing unit <NUM> accommodated in the outer sheath <NUM> is expanded, the outer sheath <NUM> is moved with respect to the shaft portion <NUM> to the proximal side. Consequently, as shown in <FIG>, the proximal sliding unit <NUM> is attached to the first proximal limit portion <NUM>, and the crushing unit <NUM> is gradually exposed from the outer sheath <NUM> and is expanded by own elastic force. Consequently, a length of the crushing unit <NUM> in the axial direction is shortened. Therefore, the distal sliding unit <NUM> moves to the proximal side and is attached to the second proximal limit portion <NUM>. When the outer sheath <NUM> is further moved with respect to the shaft portion <NUM> to the proximal side, the crushing unit <NUM> is exposed from the outer sheath <NUM> and is expanded by its own elastic force, as shown in <FIG>. Consequently, the length of the crushing unit <NUM> in the axial direction is shortened, the proximal sliding unit <NUM> moves to the distal side and is attached to the first distal limit portion <NUM>. Consequently, the crushing unit <NUM> is completely expanded. The relative rotation of the proximal sliding unit <NUM> and the distal sliding unit <NUM> with respect to the shaft portion <NUM> is limited by the proximal convex portion <NUM> and the distal convex portion <NUM>.

When the crushing unit <NUM> is accommodated in the outer sheath <NUM>, the shaft portion <NUM> is fixed at hand, and the outer sheath <NUM> is moved toward the distal side. When the distal end portion of the outer sheath <NUM> comes into contact with the crushing unit <NUM>, the crushing unit <NUM> is deformed in the distal direction and the retracting direction, as shown in <FIG>. Consequently, a length of the crushing unit <NUM> in the axial direction is elongated. Therefore, the distal sliding unit <NUM> is moved to the distal side and is attached to the second distal limit portion <NUM>. When the distal sliding unit <NUM> is attached to the second distal limit portion <NUM>, it is not possible for the distal sliding unit <NUM> to move with respect to the shaft portion <NUM>. Therefore, a force for pressing between the distal sliding unit <NUM> and the proximal sliding unit <NUM> in the axial direction acts on the crushing unit <NUM>. Consequently, as shown in <FIG>, the crushing unit <NUM> is completely accommodated in the outer sheath <NUM> while being retracted in the radial direction, and the length of crushing unit in the axial direction increases. Hence, the proximal sliding unit <NUM> moves to the proximal side and is attached to or approaches the first proximal limit portion <NUM>.

As described above, in the medical device, the contact portions of the proximal convex portion <NUM> and the distal convex portion <NUM>, which come into contact with the proximal sliding unit <NUM> and the distal sliding unit <NUM>, respectively, are disposed to be divided in the axial direction. Consequently, a moving distance of the proximal sliding unit <NUM> and the distal sliding unit <NUM>, which move in the axial direction such that the crushing unit <NUM> 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 <NUM> is improved, and the operability in the living body is improved.

In addition, the medical device includes the first distal limit portion <NUM> and the second distal limit portion <NUM>, which limit movement of the proximal sliding unit <NUM> and the distal sliding unit <NUM> to the distal side with respect to the shaft portion <NUM>, and the first proximal limit portion <NUM> and the second proximal limit portion <NUM>, which limit the movement thereof to the proximal side. Consequently, the movement of the crushing unit <NUM> is limited such that the crushing unit <NUM> can be released from the outer sheath <NUM> and accommodated in the outer sheath <NUM>. In addition, since the size of the crushing unit <NUM> 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 <NUM> and the second distal limit portion <NUM>), which limit the movement of the sliding units (the sliding unit <NUM> and the distal sliding unit <NUM>) with respect to the shaft portion <NUM> 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 <NUM> and the second proximal limit portion <NUM>), which limit the movement of the sliding units (the sliding unit <NUM> and the distal sliding unit <NUM>) to the proximal side with respect to the shaft portion <NUM> are provided; however, only one of the proximal limit portions may be provided.

In addition, the body lumen, into which the medical device <NUM> 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 <NUM>, the inner sliding portion <NUM>, and the outer sliding portion <NUM>).

Claim 1:
A medical device (<NUM>) for crushing an object in a body lumen by being inserted into the corresponding body lumen, the device (<NUM>) comprising:
an elongated shaft portion (<NUM>) that is to be rotatably driven;
a crushing unit (<NUM>) that is provided with bendable wire rods and is rotatable together with the shaft portion (<NUM>); and
a sliding unit (<NUM>) that is fixed to each of end portions of the wire rods on at least one of a distal side and a proximal side thereof and is interlocked with the shaft portion (<NUM>) so as to be slidable in an axial direction of the shaft portion (<NUM>),
characterized in that the shaft portion (<NUM>) is provided with a contact portion (<NUM>) that is to come into contact with the sliding unit (<NUM>) during rotation and is to limit relative rotation of the shaft portion (<NUM>) and the sliding unit (<NUM>), and
wherein, after the sliding unit (<NUM>) is attached to the contact portion (<NUM>), the sliding unit (<NUM>) rotates in the same direction as the shaft portion (<NUM>) along with the rotation of the shaft portion (<NUM>),
wherein one of the sliding unit (<NUM>) and the shaft portion (<NUM>) is provided with a slit (<NUM>) or a groove (<NUM>) in the axial direction of the shaft portion (<NUM>), and
wherein the other of the sliding unit (<NUM>) and the shaft portion (<NUM>) is provided with a convex portion (<NUM>) that is to be slidably fitted into the slit (<NUM>) or the groove (<NUM>).