WO2014050465A1

WO2014050465A1 - Expansion device

Info

Publication number: WO2014050465A1
Application number: PCT/JP2013/073751
Authority: WO
Inventors: 中川雄司
Original assignee: テルモ株式会社
Priority date: 2012-09-28
Filing date: 2013-09-04
Publication date: 2014-04-03

Abstract

An expansion device (10) according to the present invention is for expanding an interosseous gap, comprising: a catheter (16) which draws a filling material within a spacer (18) which is disposed at the leading end thereof; a sheath (12) further comprising a lumen (14) wherethrough the catheter (16) passes and which is capable of housing the spacer (18) prior to expansion; and an engagement part (20) which retains relative locations of the catheter (16) and the sheath (12) with respect to the catheter (16) in the axial direction with the total length of the spacer (18) exposed from the sheath (12).

Description

Expansion device

The present invention relates to an expansion device for expanding an interval between bones.

Lumbar spinal canal stenosis is a disease in which the spinal canal is constricted due to retrograde degeneration of the intervertebral disc or ligament, and causes symptoms such as low back pain, leg pain, and intermittent claudication. The mainstream of treatment for lumbar spinal canal stenosis is an operation that removes a part of the spine where the spinal canal is narrowed (laminectomy) or an operation that fixes the spine (spine fusion). On the other hand, as a relatively minimally invasive technique compared to laminectomy or spinal fusion, a metal spacer has recently been placed between the spinous processes to release the spinal nerve and nerve root compression. It has been developed. However, this method requires the incision of the back muscles and ligaments to place the spacer, so that the degree of invasiveness to the patient is still high, and hospitalization is also prolonged.

In response to such a problem, another method has been proposed in which a spacer is inserted between spinous processes and placed in a less invasive manner. In the other method, the sheath is inserted percutaneously between the spinous processes, and the expandable spacer provided at the distal end of the catheter is inserted into the lumen of the sheath in a folded state and placed between the spinous processes. Then, the spacer is expanded by filling the spacer with a filler such as bone cement and placed between the spinous processes. Since the filler is cured after filling the spacer, the spacer can maintain the expanded state semipermanently.

By the way, in Japanese translations of PCT publication No. 2012-518440, in the field of cardiac ablation using a catheter, a technical idea of restraining the movement along the axial direction of the catheter relative to the sheath by a chuck mechanism provided at the rear end of the sheath. Is disclosed.

Further, in Japanese Patent No. 3654355, in a field such as IABP, PTCA, or TDC, a fixing ring provided at the rear end portion of the sheath and made of an elastic material is compressed in the axial direction. A technical idea for fixing a catheter tube to a sheath by press-contacting the outer periphery of the tube is disclosed.

Further, in Japanese Patent Application Laid-Open No. 8-280813, in the field of angiography, there is a technical idea of fixing a catheter to a sheath by attaching a catheter fixture in the form of a so-called laundry scissor to the rear end of the sheath. It is disclosed.

When a spacer is placed between the spinous processes, the center of the spacer in the axial direction needs to be positioned at the center of the width direction of the interspinous ligament between adjacent spinous processes. However, when the spacer disposed between the spinous processes is filled with a filler, the spacer is displaced (slip) with respect to the spinous processes, and the center of the spacer in the axial direction is shifted from the center of the interspinous ligament in the width direction. May end up.

This is because the spacer is folded asymmetrically in the axial direction, or the spacer hits the surrounding tissue (bone, muscle, ligament, etc.), so that either the tip or the rear end of the spacer expands first. It is generated by doing.

That is, for example, when the distal end portion of the spacer is expanded first, there is a reaction force that pushes the spacer toward the distal end when the distal end side of the spacer contacts the spinous process in a state where the rear end side of the spacer is not in contact with the spinous process. Since the spinous process acts on the spacer, the spacer is displaced relative to the distal end relative to the spinous process.

Similarly, for example, when the rear end portion of the spacer expands first, the rear end side of the spacer contacts the spinous process in a state where the front end side of the spacer is not in contact with the spinous process, and the spacer is moved to the rear end side. Since the reaction force that pushes against the spinous process acts on the spacer, the spacer is displaced relatively to the rear end side with respect to the spinous process.

Such misalignment becomes prominent when the spacer has large irregularities such as a so-called H-type or dumbbell-type. If the center of the spacer in the axial direction largely deviates from the center in the width direction of the interspinous ligament due to the positional shift, the interval between adjacent spinous processes may not be effectively expanded by the spacer. .

As a method for preventing the positional displacement of the spacer, for example, it is conceivable to provide a mechanism for fixing the catheter to the sheath held by the muscle when filling the spacer with the filler.

According to the above-described prior art, the technical idea of fixing the catheter to the sheath is disclosed, but these prior arts do not relate to an expansion device for expanding the interval between bones (for example, between spinous processes). In addition, since the above-described problem and purpose are completely different, it is not easy to apply the technical idea related to the conventional technology to the expansion device.

The present invention has been made in consideration of such problems, and can prevent the spacer from being displaced when the spacer is filled with the filler, thereby ensuring the spacing between the bones. An object is to provide an expansion device that can be expanded.

[1] An expansion device according to the present invention is an expansion device for expanding an interval between bones, and is configured to be expandable and provided between the bones, and the spacer is provided at a distal end. A catheter for guiding the filler into the spacer, a sheath through which the catheter is inserted and capable of accommodating the spacer before expansion, and the catheter in a state where the entire length of the spacer is exposed from the sheath. And locking means for holding a relative position of the sheath along the axial direction of the catheter.

According to the expansion device of the present invention, the spacer includes the locking means for holding the relative position of the catheter and the sheath along the axial direction of the catheter in a state where the entire length of the spacer is exposed from the sheath. When filling the inside with the filler, it is possible to suppress relative displacement of the catheter along the axial direction with respect to the sheath held by the muscle. Thereby, even if it is a case where either one of the front-end | tip part of a spacer and a rear-end part is expanded previously, it can suppress that this spacer shifts | deviates. Therefore, since the spacer can be placed at a predetermined position, the interval between the bones can be reliably expanded.

[2] In the above expansion device, the locking means may have a stopper fixed to the catheter and fitted to the rear end of the sheath.

According to such a configuration, the relative position of the catheter and the sheath along the axial direction of the catheter can be maintained with a simple configuration by fitting the stopper fixed to the catheter to the rear end portion of the sheath. can do.

[3] In the expansion device described above, the stopper may be configured to be elastically deformable and may be formed in a tapered shape that decreases in diameter toward the tip.

According to such a configuration, since the elastically deformable stopper is formed in a tapered shape that decreases in diameter toward the tip, the tip of the stopper can be moved radially inward simply by sliding the sheath to the rear end. It can be fitted into the opening on the rear end side of the sheath in an elastically deformed state. Thereby, since the stopper can be fixed to the sheath by its elastic force, the relative position between the catheter and the sheath can be suitably held.

[4] In the above expansion device, the locking means includes a fixed portion that is formed at an insertion hole through which the catheter can be inserted and is fixed to a rear end portion of the sheath, and the catheter that communicates with the insertion hole. A movable portion formed with a hole portion through which the catheter can be inserted, and the movable portion includes a wall position constituting the insertion hole and a wall surface constituting the hole portion, and a locking position for sandwiching the catheter and the clamping portion It may be provided in the fixed part in a state displaceable to a release position where the is released.

According to such a configuration, the catheter can be sandwiched between the wall surface constituting the insertion hole of the fixed portion and the wall surface constituting the hole portion of the movable portion by arranging the movable portion at the lock position. And the relative position of the sheath can be maintained. Further, since the holding is released by disposing the movable portion at the release position, the spacer can be disposed between the bones by inserting the catheter into the lumen of the sheath.

[5] In the above expansion device, the locking means may include a movable part urging means for urging the movable part so that the movable part is in the locked position.

According to such a configuration, the movable part is urged by the movable part urging means so that the movable part is in the locked position. Therefore, the user and the like do not operate the movable part. The relative position can be maintained. In this case, the user or the like can easily switch the movable portion from the lock position to the release position by pressing the movable portion in a direction opposite to the urging direction of the movable portion urging means.

[6] In the expansion device described above, the locking means is inserted into the nut portion in which a tapered female screw portion that is fixed to the rear end portion of the sheath and has a diameter reduced toward the distal end is formed, and the catheter is inserted. And a screw member having a male screw portion that is formed with a slit extending along the through hole and screwed into the female screw portion, and the screw member includes the male screw portion. You may hold | maintain the said catheter inserted into the said through-hole by reducing the diameter by screwing in the said internal thread part, and making it advance to a front end side.

According to such a configuration, the catheter inserted into the through hole of the screw member by reducing the diameter of the screw member by screwing the male screw portion of the screw member into the tapered female screw portion of the nut portion and moving the screw member forward. Since it can hold | maintain, the said relative position of a catheter and a sheath can be hold | maintained by simple structure.

[7] In the above expansion device, the locking means includes an elastic member in which an inner hole through which the catheter is inserted is formed, a holding portion that is fixed to a rear end portion of the sheath and holds the elastic member, The elastic member may be pressed from the axial direction to be compressed and deformed and the inner hole may be reduced in diameter to hold the catheter inserted through the inner hole.

According to such a configuration, the catheter inserted through the inner hole can be held by pressing the elastic member from the axial direction by the pressing means to compress and deform and reducing the diameter of the inner hole of the elastic member. Therefore, the relative position between the catheter and the sheath can be maintained with a simple configuration.

[8] In the above expansion device, the locking means includes a first engagement portion provided in the catheter, a first support portion fixed to a rear end portion of the sheath, and an axial direction of the sheath. A second support portion provided on the first support portion in an inoperable state; and a second engagement portion provided on the second support portion and engageable with the first engagement portion. It may be.

According to such a configuration, the first support portion fixed to the rear end portion of the sheath is provided with the second support portion so as not to move in the axial direction of the sheath, and the first engagement portion provided on the catheter The relative position between the catheter and the sheath can be maintained by engaging the second engagement portion provided on the second support portion.

[9] In the above expansion device, one of the first engagement portion and the second engagement portion is a convex portion, and the other of the first engagement portion and the second engagement portion is It may be a convex part or a concave part.

According to such a configuration, either one of the first engaging portion and the second engaging portion is a convex portion, and either one of the first engaging portion and the second engaging portion is a convex portion or Since it is a recessed part, the said relative position of a catheter and a sheath can be suitably hold | maintained by engaging these convex part and recessed part (convex part and convex part).

[10] In the above expansion device, the locking means may hold the relative position of the catheter and the sheath at both the distal end portion and the rear end portion of the sheath.

According to such a configuration, the locking means holds the relative position between the catheter and the sheath at both the distal end portion and the rear end portion of the sheath. Compared with the case where the position is maintained, the displacement of the spacer can be more effectively suppressed.

[11] In the above expansion device, the locking means has an expandable expansion stopper fixed to the distal end side of the catheter, and the expansion stopper is in a state where the entire length of the spacer is exposed from the sheath. The sheath may be exposed and expanded to contact the tip of the sheath.

According to such a configuration, the expansion stopper is exposed from the sheath in a state where the entire length of the spacer is exposed from the sheath and comes into contact with the distal end of the sheath. Even if it is a case where it pushes to the rear end side, it can suppress suitably that a catheter displaces with respect to a sheath.

[12] In the above expansion device, the locking means is provided in a locking recess formed on the distal end side of the catheter and an arrangement hole formed in an inner surface on the distal end side of the sheath. And a fitting portion urging means for urging the fitting portion toward the radially inner side of the sheath.

According to such a configuration, by fitting the fitting portion provided in the arrangement hole formed on the distal end side of the sheath into the locking recess formed on the distal end side of the catheter, The relative position between the catheter and the sheath can be reliably held.

According to the expansion device of the present invention, the distal end portion of the spacer is provided with the locking means that holds the relative position of the catheter and the sheath along the axial direction of the catheter in a state where the entire length of the spacer is exposed from the sheath. Even if either one of the rear end portion and the rear end portion is expanded first, it is possible to suppress the displacement of the spacer, and thereby it is possible to reliably expand the interval between the bones.

It is a partial cross section top view of the expansion device which concerns on 1st Embodiment of this invention. FIG. 2A is an explanatory view showing a state in which the distal end portion of the sheath constituting the expansion device is inserted between the spinous processes, and FIG. 2B is a diagram showing a state in which the spacer constituting the expansion device is disposed at the distal end portion of the sheath. It is explanatory drawing which showed the state which carried out. 3A is a partially omitted enlarged cross-sectional view of the expansion device shown in FIG. 2B, and FIG. 3B is a partially omitted enlarged cross-sectional view showing a state in which the relative positions of the catheter and the sheath are held in the expansion device. FIG. 4A is a partially omitted enlarged cross-sectional view showing a state in which the leading end portion of the spacer is expanded first, and FIG. 4B is a partially omitted enlarged cross-sectional view showing a state in which the entire spacer is expanded. It is explanatory drawing which showed the state which removed the catheter of the said expansion device from the spacer. FIG. 6A is a partially omitted enlarged cross-sectional view of an expansion device according to a second embodiment of the present invention, and FIG. 6B is a partially omitted view showing a state in which the relative position between the catheter and the sheath is maintained in the expansion device. It is an expanded sectional view. 7A is a longitudinal sectional view taken along line VIIA-VIIA in FIG. 6A, and FIG. 7B is a longitudinal sectional view taken along line VIIB-VIIB in FIG. 6B. FIG. 8A is a partially omitted enlarged sectional view of an expansion device according to a third embodiment of the present invention, and FIG. 8B is a partially omitted illustration showing a state in which the relative position between the catheter and the sheath is maintained in the expansion device. It is an expanded sectional view. FIG. 8B is a cross-sectional view taken along line IX-IX in FIG. 8A. FIG. 10A is a partially omitted enlarged cross-sectional view of a dilation device according to a modification of the third embodiment, and FIG. 10B is a partial omission showing a state in which the relative position between the catheter and the sheath is maintained in the dilation device. It is an expanded sectional view. 11A is a cross-sectional view taken along line XIA-XIA in FIG. 10A, and FIG. 11B is a cross-sectional view taken along line XIB-XIB in FIG. 10B. It is a partially-omission perspective view of the rear end side of the expansion device according to the fourth embodiment of the present invention. 13A is a partially omitted enlarged cross-sectional view taken along line XIIIA-XIIIA in FIG. 12, and FIG. 13B is a cross-sectional view of FIG. 12 in which the relative position between the catheter and the sheath is maintained in the expansion device. It is a partially abbreviated enlarged sectional view along line XIIIB. FIG. 14A is a partially omitted enlarged cross-sectional view of a dilation device according to a fifth embodiment of the present invention, and FIG. 14B is a partial omission showing a state in which the relative position between the catheter and the sheath is maintained in the dilation device. It is an expanded sectional view. FIG. 15A is a partially omitted enlarged cross-sectional view of an expansion device according to a sixth embodiment of the present invention, and FIG. 15B is a partially omitted illustration showing a state in which the relative position between the catheter and the sheath is maintained in the expansion device. It is an expanded sectional view.

Hereinafter, preferred embodiments of the expansion device according to the present invention will be exemplified and described with reference to the accompanying drawings.

(First embodiment)
The expansion device 10 according to the present embodiment is for expanding the interval between the bones by inserting the spacers 18 between the bones and expanding the spacers. The part into which the spacer 18 is inserted is, for example, between spinous processes, a shoulder joint, or an intervertebral disc.

As shown in FIG. 1, the expansion device 10 includes a hollow arc-shaped sheath 12, a long catheter 16 that can be inserted into the lumen 14 of the sheath 12, and a spacer 18 provided at the distal end of the catheter 16. And a locking portion (locking means) 20 for maintaining the relative position of the catheter 16 and the sheath 12.

The sheath 12 is configured as an outer needle. That is, the sheath 12 can puncture a living body with the inner needle 22 disposed in the lumen 14 and the distal end of the inner needle 22 protruding from the distal end of the sheath 12 by a predetermined length (see FIG. 2A). Note that the inner needle 22 used when the sheath 12 is punctured into the living body is formed in an arc shape having the same curvature as the sheath 12, and has a sharp or blunt needle tip at the tip.

The constituent material of the sheath 12 and the inner needle 22 is not particularly limited as long as it is a hard material having an appropriate strength that is not damaged or deformed when puncturing the living body. For example, stainless steel, aluminum alloy, cobalt Examples thereof include metals such as alloys and copper alloys, and hard resins such as polyvinyl chloride, polyethylene, and fluororesin. An X-ray impermeable marker may be provided on at least a part of the distal end side of the sheath 12 or the inner needle 22 so as to be recognized under X-ray fluoroscopy.

In the inner cavity 14 of the sheath 12, a catheter 16 can be inserted and a folded unfolded spacer 18 can be accommodated. An inclined surface 24 that is inclined with respect to the axis of the sheath 12 is formed on the inner surface of the rear end portion of the sheath 12 so as to gradually become thinner toward the rear end side.

The catheter 16 is a flexible tube member having flexibility, and the filler can be guided to the spacer 18 through the lumen. A filling material supply source (not shown) such as a syringe and a pump is connected to the rear end side of the catheter 16.

The filler is a fluid when injected into the spacer 18 and is a material that hardens after injection (eg, bone cement, acrylic resin, two-component mixed cross-linked polymer, etc.), or a fluid when injected, and maintains the fluid after injection. Any of the materials to be applied can be applied.

The catheter 16 has appropriate flexibility and appropriate strength (koshi, rigidity) so that the lumen 14 of the arc-shaped sheath 12 can be inserted and the filler can be guided to the spacer 18. Yes. As a constituent material of the catheter 16, for example, a polymer material such as polyolefin, polyvinyl chloride, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, fluororesin, and silicone resin, or a mixture thereof, or the above two or more kinds of high materials are used. Examples thereof include molecular materials.

The catheter 16 and the spacer 18 are detachably connected. The connection structure 26 between the catheter 16 and the spacer 18 is, for example, a screwed structure, and when a predetermined torque or more is applied to the catheter 16 and the spacer 18, the screwing is released, whereby the catheter 16 and the spacer 18 are connected. Are supposed to separate.

In addition to the above-described screwed structure, the connection structure 26 includes a structure in which the members are separably connected by physical engagement (fitting, hooking, etc.), and some physical action (thermal action, chemical action, etc.). ) Can be separated so as to be separable.

The spacer 18 is configured as a balloon and is folded into a tubular state when contracted, and has a structure in which a pair of bulging

portions

28 and 30 are connected via a constricted portion 32 when expanded (see FIG. 4B). When the shape of the spacer 18 at the time of expansion is a dumbbell type, a wheel type (H type), or the like, the pair of bulging

portions

28 and 30 disposed on both sides of the constricted portion 32 inserted into the interspinous ligament are spinous processes. Is preferable because the shape is sandwiched.

The material of the spacer 18 is not particularly limited as long as the material can be expanded by being injected with a filler and can withstand the external pressure associated with the movement of the vertebral body and tissues such as spinous processes and interspinous ligaments surrounding the spacer 18. For example, vinyl chloride, polyurethane elastomer, nylon, PET and the like can be mentioned.

The locking portion 20 is a relative position of the catheter 16 and the sheath 12 along the axial direction of the catheter 16 in a state where the sheath 12 is slid to the rear end side of the catheter 16 and the entire length of the spacer 18 is exposed to the distal end side of the sheath 12. And has a stopper 34 fixed to the proximal end side of the catheter 16.

The stopper 34 is formed in the shape of a truncated cone having a reduced diameter on the distal end side, and is provided integrally with the catheter 16. That is, the stopper 34 is formed in a tapered shape that decreases in diameter toward the tip. Specifically, the stopper 34 is formed so that the outer diameter of the tip is smaller than the inner diameter of the sheath 12 and the outer diameter of the rear end is larger than the outer diameter of the sheath 12. Further, the taper angle of the taper surface (outer peripheral surface) 36 of the stopper 34 substantially matches the inclination angle of the inclined surface 24 formed at the rear end portion of the sheath 12.

The stopper 34 can be made of the same material as the catheter 16. That is, the stopper 34 can be elastically deformed, and the distal end side thereof can be fitted into the opening on the rear end side of the sheath 12 (see FIG. 3B).

The expansion device 10 according to the present embodiment is basically configured as described above, and the operation and effect thereof will be described below.

Here, mainly with reference to FIGS. 2A to 5, a procedure for percutaneously inserting and placing the spacer 18 between adjacent spinous processes in the living body using the above-described inner needle 22 and the expansion device 10 will be described. . 2A to 5, reference numeral B is a vertebra, reference numeral S is a spinous process formed at the rear of the vertebra B, and reference numeral L is an interspinous ligament formed between adjacent spinous processes. .

First, after confirming the lesioned part with an X-ray fluoroscope, MRI, ultrasonic diagnostic apparatus, etc., the patient P is placed in the prone position. Next, as shown in FIG. 2A, the patient P is inserted with the inner needle 22 inserted into the sheath 12 so that the tip of the inner needle 22 is exposed at the distal end side of the sheath 12 constituting the expansion device 10. Thus, the sheath 12 and the inner needle 22 penetrate the interspinous ligament between adjacent spinous processes in a direction crossing the axial direction of the spine.

In this case, the distal end portion of the sheath 12 is inserted into a position beyond a distance between the spinous processes by a predetermined length. After the sheath 12 and the inner needle 22 have been inserted for a desired length, the inner needle 22 is then removed from the sheath 12 while maintaining the position of the sheath 12, that is, while the sheath 12 is inserted into the patient P. In place. In this state, the sheath 12 is held by the surrounding muscles.

Next, as shown in FIG. 2B, a catheter 16 having a spacer 18 at the tip is inserted into the lumen 14 of the sheath 12. Here, the catheter 16 is inserted so that the axial center of the spacer 18 is positioned at the center of the interspinous ligament between adjacent spinous processes.

After inserting the catheter 16 to a predetermined position of the sheath 12, next, the sheath 12 is slid toward the rear end while maintaining the position of the spacer 18, as shown in FIGS. 3A and 3B. In this case, the sheath 12 is slid in the rear end direction until the full length of the spacer 18 is exposed.

Then, the tapered surface 36 of the stopper 34 slides toward the distal end side of the inclined surface 24 of the sheath 12, so that the distal end portion of the stopper 34 is elastically deformed radially inward into the opening on the rear end side of the sheath 12. Insert. Accordingly, the stopper 34 is fixed to the sheath 12 by its elastic force (restoring force, elastic force), and the relative position of the catheter 16 and the sheath 12 along the axial direction of the catheter 16 is maintained (the catheter 16 Is fixed to the sheath 12).

Subsequently, the filler supply source (not shown) is operated to inject the filler into the spacer 18 through the catheter 16 to expand the spacer 18. At this time, the spacer 18 is asymmetrically folded in the axial direction, or the spacer 18 hits the surrounding tissue (bone, muscle, ligament, etc.), so that either the front end portion or the rear end portion of the spacer 18 is May be extended first.

For example, as shown in FIG. 4A, when the distal end portion of the spacer 18 expands first, the bulging portion 30 on the distal end side of the spacer 18 comes into contact with the spinous process, and the reaction force from the spinous process causes the distal end side to move toward the distal end side. It will be pressed. On the other hand, although illustration is omitted, when the rear end portion of the spacer 18 is expanded first, the bulging portion 28 on the rear end side comes into contact with the spinous process and is pressed toward the rear end side by a reaction force from the spinous process. It will be.

In the present embodiment, even when either one of the leading end portion and the trailing end portion of the spacer 18 is expanded first in this way, the sheath 12 is in a state in which the leading end portion of the stopper 34 is elastically deformed radially inward. Since the relative position between the catheter 16 and the sheath 12 is maintained by being fitted into the opening on the rear end side, the spacer 18 can be prevented from being displaced with respect to the spinous process.

When the filling of the filler into the spacer 18 is completed, as shown in FIG. 4B, a pair of bulging

portions

28 and 30 are connected via the constricted portion 32, and the constricted portion 32 is formed between the spinous processes. The spinous processes are located between the pair of bulging

portions

28 and 30 on both sides thereof. Thereby, the space | interval between spinous processes is expanded by the expanded constriction part 32, and the spacer 18 will be in the state from which the removal | extraction from the interspinous ligament between spinous processes was prevented.

As shown in FIG. 5, when the spacer 18 is expanded, the catheter 16 is detached from the spacer 18. When the connection structure 26 of the spacer 18 and the catheter 16 is a screwed structure, when the catheter 16 is rotated around its axis, the spacer 18 inserted in the interspinous ligament between adjacent spinous processes does not rotate, and the catheter 16 Only the rotation causes the spacer 18 and the catheter 16 to be unscrewed. Thereby, the catheter 16 can be detached from the spacer 18.

In addition, when the filler is a material that is a fluid at the time of injection and is cured after the injection, the spacer 18 and the catheter 16 are preferably separated after the filler is cured. In addition, when the filler is a material that maintains the fluid even after injection, a backflow prevention structure (check valve) may be provided at the inlet of the spacer 18.

When the catheter 16 is detached from the spacer 18, the catheter 16 is removed from the sheath 12, and the sheath 12 is completely removed from the patient P. As a result, the spacer 18 is placed between the spinous processes.

As described above, according to the expansion device 10 according to the present embodiment, the sheath 12 is slid to the rear end side in a state where the axial center of the spacer 18 is positioned at the center of the width direction of the interspinous ligament. When the entire length of the spacer 18 is exposed from the sheath 12, the distal end portion of the stopper 34 fixed to the catheter 16 is elastically deformed radially inward and fitted (fitted) into the opening on the rear end side of the sheath 12. Can be made.

Thereby, since the relative position along the axial direction of the catheter 16 between the catheter 16 and the sheath 12 can be maintained with a simple configuration, either the front end portion or the rear end portion of the spacer 18 is expanded first. Even in this case, the spacer 18 can be prevented from being displaced with respect to the spinous process. That is, since the spacer 18 can be placed at a predetermined position, the interval between the spinous processes can be expanded reliably.

In the present embodiment, since the inclined surface 24 is formed on the inner surface of the rear end portion of the sheath 12 and the tapered surface 36 is formed on the stopper 34, the distal end of the stopper 34 is simply slid to the rear end side. The portion can be fitted into the opening on the rear end side of the sheath 12 with the portion elastically deformed radially inward.

This embodiment is not limited to the configuration described above. In the expansion device 10 according to the present embodiment, the inclined surface 24 may not be formed on the sheath 12. Even in this case, if the tapered surface 36 is formed on the stopper 34, the distal end portion of the stopper 34 can be moved to the opening on the rear end side of the sheath 12 just by sliding the sheath 12 to the rear end side. Can be inserted.

If the stopper 34 can be fitted into the opening on the rear end side of the sheath 12, the shape of the stopper 34 can be arbitrarily changed. For example, the stopper 34 may be formed in a cylindrical shape that can be fitted onto the rear end of the sheath 12. In this case, if the stopper 34 is configured to be elastically deformable, and if the cylindrical stopper 34 is elastically deformed radially outwardly and fitted to the rear end portion of the sheath 12, the catheter 16 and the sheath 12 The relative position can be maintained.

(Second Embodiment)
Next, an expansion device 10A according to a second embodiment of the present invention will be described with reference to FIGS. 6A to 7B. Note that in the expansion device 10A according to the present embodiment, elements having the same or similar functions and effects as those of the expansion device 10 described above are denoted by the same reference numerals, and detailed description thereof is omitted. The same applies to expansion devices 10B to 10E according to third to sixth embodiments to be described later.

In FIGS. 6A and 6B, the surrounding tissue (spinous process, interspinous ligament, etc.) of the spacer is not shown, and FIGS. 8A, 8B, 10A, 10B, and 13A to 15B are also shown. It is the same.

As shown in FIGS. 6A and 7A, the expansion device 10A according to the present embodiment is provided with a locking portion 40 instead of the locking portion 20 described above. Note that the inclined surface 24 described above is not formed in the sheath 12 according to the present embodiment. The same applies to the sheath 12 according to third and fourth embodiments described later.

The locking portion 40 includes a fixed portion 44 in which the groove portion 42 is formed, a movable portion 46 disposed in the groove portion 42, and an urging member (movable) interposed between the bottom surface of the groove portion 42 and the movable portion 46. Part biasing means) 48.

The groove portion 42 is open on the surface of the fixed portion 44 that is oriented in the radial direction of the sheath 12. The fixing portion 44 is formed with a first insertion hole 50 and a second insertion hole 52 through which the catheter 16 can be inserted. Each of the first insertion hole 50 and the second insertion hole 52 extends along the axial direction of the catheter 16. The first insertion hole 50 is located on the rear end side of the fixing portion 44, and the second insertion hole 52 is in communication with the lumen 14 of the sheath 12 in a state of being located on the distal end side of the fixing portion 44.

A part of the movable part 46 protrudes from the groove part 42 in a state of being arranged in the groove part 42. The movable portion 46 is formed with a hole portion 54 through which the catheter 16 can be inserted. The hole portion 54 communicates with each of the first insertion hole 50 and the second insertion hole 52 in a state where the movable portion 46 is disposed in the groove portion 42.

In addition, the movable portion 46 has a lock position (see FIGS. 6B and 7B) where the catheter 16 is sandwiched between the wall surface constituting the first insertion hole 50 and the wall surface constituting the second insertion hole 52 and the wall surface constituting the hole portion 54. And a release position (position shown in FIGS. 6A and 7A) where the clamping is released.

As the biasing member 48, for example, a spring member such as a compression coil spring or an elastic member can be used. 6A to 7B show an example in which a spring member is used as the biasing member 48. FIG. The urging member 48 urges the movable portion 46 along the protruding direction of the movable portion 46 with respect to the groove portion 42. That is, the urging member 48 urges the movable part 46 so that the movable part 46 is in the locked position.

In the expansion device 10A configured as described above, the movable portion 46 urged by the urging member 48 is positioned at the lock position in a state where the user (operator) or the like is not touching the movable portion 46 ( 6B and 7B). When the user or the like presses the protruding portion of the movable portion 46, the movable portion 46 is positioned at the release position while compressing the biasing member 48 (see FIGS. 6A and 7A).

In this embodiment, the user or the like pushes the protruding portion of the movable portion 46 so that the movable portion 46 is positioned at the release position, and the spacer 18 is placed in the lumen 14 of the sheath 12 inserted between the spinous processes. A catheter 16 provided at the distal end can be inserted.

Further, after the sheath 12 is slid to the rear end side and the entire length of the spacer 18 is exposed from the sheath 12, the user or the like releases the pressing of the movable portion 46 and positions the movable portion 46 in the locked position. Thereby, the relative position of the catheter 16 and the sheath 12 is maintained. In this state, a filler is injected into the spacer 18.

In this case, even if it is a case where either the front-end | tip part or the rear-end part of the spacer 18 is expanded first, it can suppress that the spacer 18 shifts | deviates with respect to a spinous process (the catheter 16 is sheath 12). The distance between the spinous processes can be reliably expanded.

According to the present embodiment, since the movable portion 46 is urged by the urging member 48 so that the movable portion 46 is in the locked position, the movable portion 46 is operated when filling the spacer 18 with the filler. Even if not, the relative position of the catheter 16 and the sheath 12 can be maintained. In this case, the movable part 46 can be easily switched from the lock position to the release position by pushing the movable part 46 in the direction opposite to the urging direction of the urging member 48.

This embodiment is not limited to the configuration described above. The expansion device 10 A according to the present embodiment may be provided with the movable portion 46 at the rear end of the fixed portion 44. In this way, it is not necessary to form the above-described groove portion 42 in the fixing portion 44. In this case, the urging member 48 can be omitted. That is, the user or the like operates the movable portion 46 to switch between the lock position and the release position, and when the movable portion 46 is in the lock position, the position of the movable portion 46 does not return to the release position due to the elastic force of the catheter 16. It is only necessary to hold the movable portion 46.

(Third embodiment)
Next, an expansion device 10B according to a third embodiment of the present invention will be described with reference to FIGS. 8A to 11B. As shown in FIGS. 8A and 9, the expansion device 10 B according to the present embodiment is provided with a locking portion 60 instead of the locking portion 20 described above.

The locking portion 60 is formed with a nut portion 64 formed with a tapered female screw portion 62 fixed to the rear end of the sheath 12 and having a diameter reduced toward the distal end side, and a male screw portion 66 screwed with the female screw portion 62. The screw member 68 is provided.

The catheter 16 is inserted through the inner hole 70 of the nut portion 64. The screw member 68 is formed with a through-hole 72 through which the catheter 16 is inserted and a plurality (four in this embodiment) of slits 74 (see FIG. 9) extending along the axial direction of the catheter 16. . The plurality of slits 74 are provided at equal angles along the axis of the screw member 68.

In the expansion device 10B configured as described above, when a user or the like tightens (rotates) the screw member 68, the male screw portion 66 of the screw member 68 is engaged with the female screw portion 62 of the nut portion 64 in the distal end side. Then, the diameter of the screw member 68 is reduced, and the wall surface constituting the through hole 72 of the screw member 68 contacts the outer surface of the catheter 16 to hold the catheter 16 (see FIG. 8B). Accordingly, the relative position between the catheter 16 and the sheath 12 can be maintained with a simple configuration (the catheter 16 can be fixed to the sheath 12).

The expansion device 10B according to the present embodiment is not limited to the configuration described above. For example, you may have the latching | locking part 60a shown to FIG. 10A-FIG. 11B.

The locking portion 60a is a screw member (pressing means) formed with a nut portion (holding portion) 64a fixed to the rear end of the sheath 12 and formed with a female screw portion 62a, and a male screw portion 66a screwed into the female screw portion 62a. ) 68a and an annular elastic member (silicone valve) 76 fitted in the inner hole 70a of the nut portion 64a.

As can be seen from FIG. 10A, the internal thread 62a is formed on the wall surface of the inner hole 70a having a constant inner diameter on the rear end side of the nut 64a. A ring-shaped movement restricting portion 78 that restricts the movement of the elastic member 76 toward the distal end side is formed on the wall surface of the nut portion 64a. A through hole 72 through which the catheter 16 is inserted is formed in the screw member 68a.

Examples of the constituent material of the elastic member 76 include various rubbers such as silicone rubber, fluororubber, isoprene and natural rubber, various resins such as polyurethane, polyamide elastomer, polybutadiene, and soft vinyl chloride, or a combination of two or more of these. And the like.

In such a modification, when a user or the like tightens (rotates) the screw member 68a, the male screw portion 66a of the screw member 68a advances to the distal end side in a state of being engaged with the female screw portion 62a of the nut portion 64a, and the screw The elastic member 76 in which the distal end surface of the member 68a is in contact with the movement restricting portion 78 is pressed toward the distal end side.

Then, the elastic member 76 is compressed and deformed in the axial direction and elastically deformed so as to expand radially inward, and the inner wall of the elastic member 76 is reduced in diameter so that the wall surface constituting the inner hole is formed on the outer surface of the catheter 16. The catheter 16 is hold | maintained by contact (refer FIG. 10B and FIG. 11B). Accordingly, the relative position between the catheter 16 and the sheath 12 can be maintained with a simple configuration (the catheter 16 can be fixed to the sheath 12).

In this modified example, the mechanism for holding the pressing means at a position where the elastic member 76 can be compressed in the axial direction to reduce the diameter of the inner hole is not the screw mechanism described above, but, for example, You may employ | adopt the structure similar to the structure described in 178179 gazette.

(Fourth embodiment)
Next, an expansion device 10C according to a fourth embodiment of the present invention will be described with reference to FIGS. 12 to 13B. As shown in FIG. 12, the expansion device 10 C according to the present embodiment is provided with a locking portion 80 instead of the locking portion 20 described above.

The locking portion 80 includes a pair of annular convex portions (first engaging portions) 82 and 84 provided on the rear end side of the catheter 16 so as to be separated from each other in the axial direction, and a U fixed to the rear end portion of the sheath 12. A pair of U-shaped first support portion 86, a U-shaped second support portion 90 connected to the first support portion 86 via a hinge 88, and a U-shape projecting from the inner surface of the second support portion 90. And convex portions (second engaging portions) 92 that can be engaged with the annular

convex portions

82 and 84.

The first support portion 86 extends along the circumferential direction of the sheath 12. The 2nd support part 90 is formed similarly to the 1st support part 86, and becomes a ring shape in the state where the 1st support part 86 and the 2nd support part 90 were piled up mutually oppositely.

The curvature of the inner surface of the convex portion 92 is set to be the same as the curvature of the outer surface of the catheter 16. The convex portion 92 is located substantially at the center in the width direction of the second support portion 90 (the axial direction of the sheath 12). The width dimension of the convex portion 92 is set to be approximately the same as the distance between the pair of annular

convex portions

82 and 84. That is, the convex portion 92 can be inserted between the pair of annular

convex portions

82 and 84.

In the expansion device 10 C configured in this way, the sheath 12 is slid to the rear end side, the entire length of the spacer 18 is exposed from the sheath 12, and the second support portion 90 is closed with respect to the first support portion 86 ( In the closed state (the state shown in FIG. 13B), the convex portion 92 can be inserted between the pair of annular

convex portions

82 and 84. At this time, the convex portion 92 is in contact with the annular

convex portions

82 and 84. Thereby, the said relative position of the catheter 16 and the sheath 12 can be hold | maintained suitably (the catheter 16 can be fixed with respect to the sheath 12).

In addition, the convex portion 92 and the annular

convex portions

82 and 84 are not in contact with each other when the second supporting portion 90 is opened with respect to the first supporting portion 86 (the state shown in FIGS. 12 and 13A). Can be inserted through the lumen 14 of the sheath 12.

This embodiment is not limited to the configuration described above. In the expansion device 10 C according to the present embodiment, an annular recess may be formed on the outer peripheral surface of the catheter 16 as the first engagement portion. In this case, the relative position between the catheter 16 and the sheath 12 can be maintained by inserting the convex portion 92 into the annular concave portion.

Further, one annular convex portion may be provided on the catheter 16 as the first engaging portion, and a concave portion may be formed on the inner surface of the second support portion 90 as the second engaging portion. In this case, the relative position between the catheter 16 and the sheath 12 can be maintained by inserting the annular convex portion into the concave portion.

That is, in the present embodiment, if the relative position between the catheter 16 and the sheath 12 can be maintained by the engagement of the first engagement portion and the second engagement portion, the first engagement portion and the first engagement portion The shape of the two engaging portions may be arbitrarily changed.

In the expansion device 10 C according to the present embodiment, it is only necessary to provide a connection portion provided on the first support portion 86 in a state in which the second support portion 90 is not movable along the axial direction of the catheter 16. It is not limited to the form of the hinge 88 described above. For example, as the connecting portion, a positioning protrusion may be formed on the first support portion 86 and a positioning hole into which the positioning protrusion can be inserted may be formed on the second support portion 90.

(Fifth embodiment)
Next, an expansion device 10D according to a fifth embodiment of the present invention will be described with reference to FIGS. 14A and 14B. As shown in FIGS. 14A and 14B, the expansion device 10D according to the present embodiment is provided with a locking portion 100 instead of the locking portion 20 described above.

The locking part 100 includes an expansion stopper 102 in addition to the stopper 34 described above. The expansion stopper 102 is fixed to the distal end side of the catheter 16. The expansion stopper 102 only needs to have an expandable mechanism, and can be configured by, for example, a shape memory alloy, a self-expanding sponge-like resin, a balloon that expands when filled with a filler, or the like.

When the expansion stopper 102 is a self-expanding type, expansion of the expansion stopper 102 by contacting the inner surface of the sheath 12 while the spacer 18 is accommodated in the sheath 12 is suppressed ( 14A). When the sheath 12 is slid to the rear end side to expose the spacer 18 and the expansion stopper 102 from the sheath 12, the expansion stopper 102 self-expands and the expansion stopper 102 and the tip of the sheath 12 come into contact with each other. Become.

When the expansion stopper 102 is a balloon that is expanded by a filler, the expansion stopper 102 is not yet expanded when the sheath 12 is slid to the rear end side to expose the spacer 18 and the expansion stopper 102 from the sheath 12. First, when a filler is injected into the catheter 16 from a filler supply source (not shown), the filler is filled in the expansion stopper 102 before being guided to the spacer 18, and the expansion stopper 102 is expanded to expand the sheath 12. It will come into contact with the tip.

In this embodiment, when the sheath 12 is slid to the rear end side and the entire length of the spacer 18 is exposed from the sheath 12, the distal end portion of the stopper 34 is elastically deformed radially inward and the rear end side of the sheath 12 is moved. The expansion stopper 102 is exposed from the sheath 12 and contacts the distal end of the sheath 12 while being fitted into the opening.

Thereby, for example, even when the rear end portion of the spacer 18 is first expanded and the spacer 18 is pressed to the rear end side by the reaction force from the spinous process, the expansion stopper 102 contacts the distal end of the sheath 12. Therefore, it is possible to suitably suppress the distal end portion of the stopper 34 from coming out of the opening portion on the rear end side of the sheath 12. Therefore, the relative position between the catheter 16 and the sheath 12 can be more reliably held (the catheter 16 and the sheath 12 can be more reliably fixed).

In the present embodiment, since the relative position between the catheter 16 and the sheath 12 is held at both the distal end portion and the rear end portion of the sheath 12, the catheter 16 and the sheath 12 between the catheter 12 and the sheath 12 are only held at the rear end portion. Compared to the case where the relative position is maintained, the spacer 18 can be more effectively suppressed from being displaced with respect to the spinous process.

This embodiment is not limited to the configuration described above. The expansion device 10D according to the present embodiment may be provided with the configuration of the locking

portions

40, 60, and 80 shown in the second to fourth embodiments described above, instead of the stopper 34.

(Sixth embodiment)
Next, an expansion device 10E according to a sixth embodiment of the present invention will be described with reference to FIGS. 15A and 15B. As shown in FIGS. 15A and 15B, the expansion device 10E according to the present embodiment is provided with a locking portion 110 instead of the locking portion 20 described above.

In addition to the stopper 34 described above, the locking portion 110 is provided in a locking recess 112 formed on the outer surface on the distal end side of the catheter 16 and an arrangement hole 114 formed on the inner surface on the distal end side of the sheath 12. It has a fitting portion 116 that fits into the stop recess 112 and a biasing member (fitting portion biasing means) 118 that biases the fitting portion 116 toward the radially inner side of the sheath 12.

The locking recess 112 can be formed in an arbitrary shape. For example, a plurality of locking recesses 112 may be formed in the circumferential direction of the catheter 16 or may be formed in an annular shape. Forming the locking recess 112 in an annular shape is preferable because it is not necessary to align the fitting portion 116 in the circumferential direction of the catheter 16.

The fitting portion 116 can be formed in an arbitrary shape, and for example, a plurality of fitting portions 116 may be formed in the circumferential direction of the sheath 12 or may be formed in an annular shape. If both the locking concave portion 112 and the fitting portion 116 are formed in an annular shape, the relative position between the catheter 16 and the sheath 12 can be suitably held in a state where the fitting portion 116 is fitted in the locking concave portion 112. It is. The arrangement hole 114 is formed in a shape corresponding to the shape of the fitting portion 116.

As the biasing member 118, for example, a spring member such as a compression coil spring or an elastic member can be used. 15A and 15B show an example in which the biasing member 118 is used and a spring member is used.

In the expansion device 10E configured as described above, the distal end portion of the stopper 34 is elastically deformed radially inward when the sheath 12 is slid to the rear end side and the entire length of the spacer 18 is exposed from the sheath 12. Thus, the fitting portion 116 can be fitted into the locking recess 112 while being fitted into the opening on the rear end side of the sheath 12.

Thereby, for example, even when the rear end portion of the spacer 18 expands first and the spacer 18 is pressed to the rear end side by the reaction force from the spinous process, the fitting portion 116 is brought into the locking recess 112. Since it is fitted, it is possible to suitably suppress the distal end portion of the stopper 34 from coming out of the opening portion on the rear end side of the sheath 12. Therefore, the relative position between the catheter 16 and the sheath 12 can be more reliably held (the catheter 16 and the sheath 12 can be more reliably fixed).

In the present embodiment, as in the fifth embodiment described above, since the relative position between the catheter 16 and the sheath 12 is held at both the distal end portion and the rear end portion of the sheath 12, only the rear end portion of the sheath 12 is retained. Thus, as compared with the case where the relative position between the catheter 16 and the sheath 12 is maintained, the spacer 18 can be more effectively prevented from being displaced with respect to the spinous process.

This embodiment is not limited to the configuration described above. In the expansion device 10E according to the present embodiment, for example, a plurality of annular locking recesses 112 are provided apart from each other in the axial direction of the catheter 16, and the same number of annular fitting portions 116 as the locking recesses 112 may be provided. Absent. In this case, the locking recesses 112 and the fitting portions 116 may be alternately arranged along the axial direction of the catheter 16. Thereby, the said relative displacement of the catheter 16 and the sheath 12 can be hold | maintained more suitably.

The expansion device 10E according to this embodiment may be provided with the configuration of the locking

portions

40, 60, and 80 shown in the second to fourth embodiments described above, instead of the stopper 34. Moreover, you may add the expansion stopper 102 shown in 5th Embodiment to these forms.

In the above description, the present invention has been described with reference to preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. Yes.

Claims

An expansion device (10, 10A-10E) for expanding the spacing between bones,
A spacer (18) configured to be expandable and disposed between the bones;
A catheter (16) provided at the tip with the spacer (18) to guide the filler into the spacer (18);
A sheath (12) having a lumen (14) through which the catheter (16) is inserted and capable of accommodating the spacer (18) before expansion;
Locking that holds the relative position of the catheter (16) and the sheath (12) along the axial direction of the catheter (16) in a state where the entire length of the spacer (18) is exposed from the sheath (12). Means (20, 40, 60, 60a, 80, 100, 110),
An expansion device (10, 10A to 10E) characterized by that.
The expansion device (10, 10D, 10E) according to claim 1,
The locking means (20, 100, 110) has a stopper (34) fixed to the catheter (16) and fitted to the rear end of the sheath (12).
An expansion device (10, 10D, 10E) characterized in that.
The expansion device (10, 10D, 10E) according to claim 2,
The stopper (34) is configured to be elastically deformable and has a tapered shape that decreases in diameter toward the tip.
An expansion device (10, 10D, 10E) characterized in that.
The expansion device (10A) according to claim 1,
The locking means (40) includes a fixing portion (44) in which insertion holes (50, 52) into which the catheter (16) can be inserted are formed and fixed to a rear end portion of the sheath (12),
A movable portion (46) formed with a hole portion (54) through which the catheter (16) can be inserted in communication with the insertion hole (50, 52);
The movable portion (46) is released from the locked position where the catheter (16) is sandwiched between the wall surface constituting the insertion hole (50, 52) and the wall surface constituting the hole portion (54), and the clamping is released. Provided in the fixed portion (44) in a displaceable state to the release position,
An expansion device (10A) characterized by that.
The expansion device (10A) according to claim 4,
The locking means (40) has a movable part biasing means (48) for biasing the movable part (46) so that the movable part (46) is in the locked position.
An expansion device (10A) characterized by that.
The expansion device (10B) according to claim 1,
The locking means (60) includes a nut portion (64) formed with a tapered female screw portion (62) fixed to the rear end portion of the sheath (12) and having a diameter reduced toward the distal end side,
A male screw part formed with a through hole (72) through which the catheter (16) is inserted and a slit (74) extending along the through hole (72) is formed and screwed into the female screw part (62). A screw member (68) having (66);
Have
The screw member (68) has a diameter reduced by screwing the male screw portion (66) into the female screw portion (62) and advancing to the distal end side, and is inserted into the through hole (72). 16)
An expansion device (10B) characterized by that.
The expansion device (10B) according to claim 1,
The locking means (60a) includes an elastic member (76) having an inner hole through which the catheter (16) is inserted;
A holding part (64a) fixed to the rear end of the sheath (12) and holding the elastic member (76);
Pressing means (68a) for holding the catheter (16) inserted through the inner hole by compressing and deforming the elastic member (76) from the axial direction and reducing the diameter of the inner hole. ,
An expansion device (10B) characterized by that.
The expansion device (10C) according to claim 1,
The locking means (80) includes a first engaging portion (82, 84) provided on the catheter (16),
A first support (86) fixed to the rear end of the sheath (12);
A second support portion (90) provided on the first support portion (86) in a state in which the sheath (12) cannot move in the axial direction;
A second engagement portion (92) provided on the second support portion (90) and engageable with the first engagement portion (82, 84).
An expansion device (10C) characterized by that.
The expansion device (10C) according to claim 8,
Either one of the first engaging portion (82, 84) and the second engaging portion (92) is a convex portion, and the first engaging portion (82, 84) and the second engaging portion ( 92) any one of the other is a convex part or a concave part,
An expansion device (10C) characterized by that.
The expansion device (10D, 10E) according to any one of claims 1 to 9,
The locking means (100, 110) holds the relative position of the catheter (16) and the sheath (12) at both the distal end and the rear end of the sheath (12).
An expansion device (10D, 10E) characterized by that.
The expansion device (10D) according to claim 10,
The locking means (100) has an expandable expansion stopper (102) fixed to the distal end side of the catheter (16),
The expansion stopper (102) is exposed and expanded from the sheath (12) in a state where the entire length of the spacer (18) is exposed from the sheath (12), and contacts the tip of the sheath (12).
An expansion device (10D) characterized by that.
The expansion device (10E) according to claim 10,
The locking means (110) includes a locking recess (112) formed on the distal end side of the catheter (16),
A fitting portion (116) provided in an arrangement hole (114) formed on the inner surface of the distal end side of the sheath (12) and capable of fitting into the locking recess (112);
Fitting portion urging means (118) for urging the fitting portion (116) toward the radially inner side of the sheath (12).
An expansion device (10E) characterized by that.