Endoscope clip device

Abstract

To provide an endoscope clip device of excellent operability.SOLUTION: An endoscope clip device 100 includes a treatment tool body 50 having a sheath 30, a sleeve 40, an operation wire 61, a movable member 71 retractable in an axial direction relative to the operation wire 61, and a transmission part 73 to be a coil spring. The treatment tool body 50 is further provided with an advancement assist part assisting advance movements of the movable member 71. The advancement assist part follows advance movements of a clip body 11 and a fastening part and advances the movable member 71 so as to advance the sleeve 40 when the operation wire 61 is pressed to a distal side after the operation wire 61 is pulled to a proximal side after timing at which retraction of the holding part 43 is regulated by the distal end of the sheath 30 during ligation operation of the clip 10.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an endoscopic clipping device. [Background technology]

[0002] 2. Description of the Related Art There is provided an endoscopic clipping device that cuts biological tissue within a body cavity under an endoscope and ligates the cut area with a clip to stop bleeding.

[0003] Patent Document 1 describes an endoscopic clip device including a treatment tool body having a clip main body having a plurality of arm portions (referred to as arm portions in the document) for grasping biological tissue and a locking portion provided on the base end side of the arm portions, and a fastening portion (referred to as a fastening member in the document) through which the plurality of arm portions are inserted and which moves forward relative to the plurality of arm portions to fasten the plurality of arm portions to a closed state, a long sheath capable of accommodating a clip, a cylindrical sleeve disposed inside the sheath and having a holding portion (referred to as an enlarged diameter portion in the document) capable of holding the fastening portion at its distal end, a manipulation wire having a clip connecting portion at its distal end that connects to and disconnects from the locking portion and is inserted through the sheath and sleeve so as to be axially movable, and a transmission portion (referred to as a coil spring in the document) which connects the manipulation wire to the sleeve and is a coil spring that transmits the forward force and backward force of the manipulation wire to the sleeve, and the proximal end of the transmission portion is fixed to the manipulation wire. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-130606 A Summary of the Invention [Problem to be solved by the invention]

[0005] According to the investigations conducted by the present inventors, there is still room for improvement in terms of operability of the clipping device for endoscopes disclosed in Patent Document 1.

[0006] The present invention has been made in consideration of the above problems, and has an object to provide a clipping device for an endoscope that is easier to operate. [Means for solving the problem]

[0007] The present invention relates to a long sheath capable of accommodating a clip having a clip body having a plurality of arm portions for gripping biological tissue and a locking portion provided on a base end side of the arm portions, and a fastening portion through which the plurality of arm portions are inserted and which advances relative to the plurality of arm portions to fasten the plurality of arm portions to a closed state; A cylindrical sleeve disposed inside the sheath, the sleeve having a holding portion at a distal end portion capable of holding the fastening portion; an operating wire having a clip connecting portion at a distal end thereof that is connected to or separated from the locking portion, and being inserted through the sheath and the sleeve so as to be movable forward and backward in an axial direction; a movable member that is movable in an axial direction relative to the operation wire; a transmission section which is a coil spring connecting the movable member and the sleeve and transmitting the forward force and the backward force of the operation wire to the sleeve; The treatment tool body includes a treatment tool body having a The treatment tool body includes an advancement assisting portion that assists the advancement of the movable member so as to advance the sleeve in accordance with the advancement of the clip body and the fastening portion, The advancement assistance portion provides an endoscopic clip device that advances the movable member to advance the sleeve in accordance with the advancement of the clip body and the fastening portion when the operating wire is pushed distally after the operating wire is further pulled proximally from the time when the retraction of the holding portion is restricted by the distal end of the sheath during the ligation operation of the clip. Effect of the Invention

[0008] According to the present invention, a clipping device for an endoscope having better operability can be realized. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic overall view of an endoscope clip according to an embodiment. FIG. [Diagram 2] 2 is a partially enlarged cross-sectional view of part A shown in FIG. [Diagram 3] FIG. 3 is a partial enlarged view of part A shown in FIG. [Figure 4] Figures 4(a) and 4(b) are cross-sectional views showing the state in which a clip is attached to the distal end of an endoscopic clip device according to an embodiment, with Figure 4(a) showing the clip in an open state and Figure 4(b) showing the clip in a closed state. [Diagram 5] 1 is a cross-sectional view showing a state in which a clip is attached to a distal end portion of an endoscopic clip device according to an embodiment, and shows a state in which a sleeve advances following the advancement of the clip. FIG. [Figure 6] 1 is a cross-sectional view showing a state in which a clip is attached to a distal end portion of an endoscopic clip device according to an embodiment, and shows a state in which a clip connecting portion has been disengaged from an engagement portion of the clip. FIG. [Figure 7] 7(a) and 7(b) are schematic diagrams for explaining a series of operations for attaching a clip to a treatment tool body of an endoscopic clip device. [Figure 8] 8(a) and 8(b) are schematic diagrams for explaining a series of operations for attaching a clip to a treatment tool body of an endoscopic clip device. [Figure 9] 13 is a cross-sectional view showing a state in which a clip is attached to a distal end portion of an endoscopic clip device according to a modified example, and shows a state in which a sleeve advances following the advancement of the clip. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and the description will be omitted as appropriate. In addition, Fig. 2 to Fig. 8(b) are cross-sectional views taken along the axis of the sheath 30. In this specification, unless otherwise specified, the "axial direction" means the axial direction of the sheath 30, which is also the same as the advancement and retreat direction of the clip connecting portion 63 of the treatment tool main body 50 when placing the clip 10. In the following description, the tip side of the endoscopic clipping device 100 in the axial direction may be referred to as the distal side, and the base end side of the endoscopic clipping device 100 may be referred to as the proximal side. The distal end portion refers to a certain range including the distal end (the most distal end) and its periphery, and the proximal end portion refers to a certain range including the proximal end (the most proximal end) and its periphery. Furthermore, the various components of the endoscopic clip device 100 in this embodiment do not need to be independent entities, and it is permitted that multiple components are formed as a single member, that one component is formed from multiple members, that one component is part of another component, that part of one component overlaps with part of another component, etc.

[0011] As shown in Figures 4(a) and 4(b), the clip 10 has a clip body 11 having a plurality of arm portions 20 for grasping biological tissue and a locking portion 25 provided on the base end side of the arm portions 20, and a clamping portion (in this embodiment, a clamping ring 15) through which the plurality of arm portions 20 are inserted and which advances relative to the plurality of arm portions 20 to clamp the plurality of arm portions 20 to a closed state. The clip 10 ligates biological tissue, and can perform treatments on the biological tissue, such as hemostasis, suturing, and marking, by ligating the biological tissue with the multiple arms 20. The arms 20 have a self-expanding force, and as described below, when the arms 20 in a closed state are caused to protrude from the sheath 30, the arms 20 naturally expand and enter an open state. Here, "self-expanding" refers to the tendency to open by itself in reaction to an external force that tries to close the arms.

[0012] As shown in any one of Figures 1 to 5, the endoscopic clip device 100 of this embodiment includes a long sheath 30 capable of accommodating the above-mentioned clip 10, a cylindrical sleeve 40 disposed inside the sheath 30, the sleeve 40 having a holding portion 43 at its distal end capable of holding a fastening portion, an operation wire 61 having a clip connecting portion 63 at its distal end that connects to or disconnects from the locking portion 25 and is inserted through the sheath 30 and the sleeve 40 so as to be movable axially forward and backward, a movable member 71 that can advance and retreat in the axial direction relative to the operation wire 61, and a transmission portion 73 that connects the movable member 71 to the sleeve 40 and is a coil spring that transmits the forward and backward forces of the operation wire 61 to the sleeve 40. The treatment tool body 50 is provided with an advancement assisting portion that assists the advancement of the movable member 71 so as to advance the sleeve 40 following the advancement of the clip body 11 and the fastening portion. During the ligation operation of the clip 10, when the operating wire 61 is further pulled proximally after the distal end of the sheath 30 has restricted the retraction of the holding portion 43, and then the operating wire 61 is pushed distally, the advancement assistance portion advances the movable member 71 to advance the sleeve 40 in conjunction with the advancement of the clip body 11 and the fastening portion. In this context, "advance" means movement toward the distal side, and "retreat" means movement toward the proximal side. Furthermore, the term "ligation" here does not necessarily mean complete ligation (a state in which the clip body 11 is irreversibly locked by the fastening portion), but rather means a state in which the fastening portion and the clip body 11 at least move forward and backward together.

[0013] In this embodiment, the advancement assistance section is composed of a structure in which the operating wire 61 and the movable member 71 are in frictional contact (a structure that slides), and a biasing member (e.g., a second coil spring 76) described later. However, in the present invention, the advancement assistance portion may be constituted only by a structure in which the operating wire 61 and the movable member 71 are in frictional contact (a structure that slides), or may be constituted only by a biasing member (e.g., the second coil spring 76).

[0014] The clip 10 is attached to the distal end of a treatment tool body 50 and is placed in a desired location in living tissue by the treatment tool body 50. The treatment tool main body 50 is used by being inserted through a forceps hole (not shown) of an endoscope. More specifically, the sheath 30 of the treatment tool main body 50 is inserted from the proximal side into the forceps hole of the endoscope placed in the living body. Then, the distal end of the sheath 30 is projected from the distal opening of the forceps hole, and the clip 10 is exposed from the sheath 30 to ligate the living tissue. Examples of the living tissue to be ligated include a mucosal wall such as a site to be treated in endoscopic submucosal dissection (ESD), as well as a body duct such as a blood vessel.

[0015] When ligating biological tissue with the clip 10, first, from a state in which the clip 10 is housed in the sheath 30, the operating wire 61 is pushed distally until the clip 10 and the fastening portion protrude from the distal end of the sheath 30. As a result, the clip 10 naturally expands to the maximum opening width due to its self-expanding force. At this time, the holding portion 43 of the sleeve 40 protrudes from the distal end of the sheath 30 and expands in diameter to its natural state diameter. As a result, the fastening portion can enter inside the holding portion 43 when expanded in diameter. Then, as the fastening portion enters inside the holding portion 43 (as the holding portion 43 grips the fastening portion from the proximal side), the holding portion 43 holds the fastening portion, and the distal end of the sheath 30 restricts the backward movement of the holding portion 43 and therefore the fastening portion. Next, the operating wire 61 is pulled proximally. This causes the fastening portion to move (advance) distally relative to the clip body 11, and the arm portion 20 in the open state (see FIG. 4(a)) is fastened by the fastening portion against the self-expanding force, thereby enabling the clip 10 to be closed (see FIG. 4(b)). This causes the clip 10 to be ligated. When the operating wire 61 is further pulled proximally from this state, the clip connecting portion 63 retreats relative to the clip body 11, and the clip 10 can be detached from the clip connecting portion 63 (see FIG. 6).

[0016] According to this embodiment, the treatment tool body 50 includes an advancement assisting portion that assists the advancement of the movable member 71 so as to advance the sleeve 40 following the advancement of the clip body 11 and the fastening portion. During the ligation operation of the clip 10, when the retraction of the holding portion 43 is restricted by the distal end of the sheath 30 and the operating wire 61 is pulled proximally, the advancement assistance portion advances the movable member 71 to advance the sleeve 40 in accordance with the advancement of the clip body 11 and the fastening portion when the operating wire 61 is pushed distally. Therefore, for example, when the operating wire 61 is pushed distally by an operation of pressing the clip body 11 against biological tissue or an erroneous operation after ligation of the clip 10, the sleeve 40 can also advance in response to the advancement of the clip 10 (the fastening portion and the clip body 11). Therefore, the state in which the holding portion 43 holds the fastening portion can be favorably maintained, so that when the operating wire 61 is subsequently pulled proximally, the retraction movement of the holding portion 43 and therefore the fastening portion can be more reliably restricted by the distal end of the sheath 30. That is, the clip 10 can be more reliably detached from the operating wire 61. Furthermore, as described above, in this embodiment, the movable member 71 can be advanced and retreated in the axial direction relative to the operation wire 61. Therefore, when the operation wire 61 is further pulled proximally from the timing when the retreat of the holding portion 43 of the sleeve 40 is restricted by the distal end of the sheath 30, the movable member 71 can be prevented from retreating following the operation wire 61. This can prevent (avoid) the transmission portion 73, which is a coil spring, from extending in the axial direction. Therefore, as described above, when the operation wire 61 is subsequently pushed distally due to an erroneous operation or the like, the sleeve 40 can immediately be advanced together with the operation wire 61. That is, the state in which the holding portion 43 holds the fastening portion can be well maintained. In this way, according to this embodiment, better operability of the clip device 100 for an endoscope can be achieved.

[0017] This embodiment will be described in more detail below.

[0018] The clip 10 includes a clip body 11 having a plurality of arm portions 20 and a locking portion 25, as well as a fastening ring 15 into which the plurality of arm portions 20 are inserted together, and the fastening ring 15 constitutes a fastening portion. The fastening ring 15 is configured to move toward the tip side of the arm portions 20 relative to the arm portions 20, so that the tips (claw portions 23) of the plurality of arm portions 20 are brought into a closed state in which they are closed to each other.

[0019] More specifically, the clip 10 has a pair of arms 20 opposed to each other. Each of the pair of arms 20 includes a base end 21 that protrudes distally (to the left in FIG. 5, etc.) from the locking portion 25, and an arm body 22 that is connected to the distal side of the base end 21. The base end 21 is curved outward toward the distal side. Here, "outward" means a direction away from the axis of the operation wire 61 or an extension of the axis, for example, a radially outward direction. "Inward" means a direction toward the axis of the operation wire 61 or an extension of the axis, for example, a radially inward direction.

[0020] The arm body parts 22 are formed in a straight line, and claw parts 23 are formed at the tips of the arm body parts 22. The arm body parts 22 and the claw parts 23 form a gripping region that mainly grips biological tissue. The claw parts 23 protrude inward from the pair of arm body parts 22, and improve the gripping force of the clip 10 by biting into the biological tissue. The arm portion 20 is bent at the boundary between the base end portion 21 and the arm body portion 22, and a narrow portion (not shown) where the width dimension of the arm portion 20 is locally reduced is formed at this boundary.

[0021] 4(a) and 4(b), the locking portion 25 and the pair of arms 20 are integrally molded to form the clip body 11. That is, the claw portion 23, the arm body portion 22, and the base end portion 21 on one side and the claw portion 23, the arm body portion 22, and the base end portion 21 on the other side are formed seamlessly and continuously via the locking portion 25. More specifically, the clip body 11 including the pair of arm portions 20 and the locking portion 25, which are integral with each other, can be produced by punching, pressing, and bending a metal plate material. Examples of such metal materials include, but are not limited to, stainless steel, titanium, and titanium alloys. The above-mentioned metal materials may also be those that have been subjected to a corrosion-resistant coating treatment.

[0022] The fastening ring 15 of the clip 10 is attached to the clip body 11 so as to be movable forward and backward with respect to the arm portion 20. By moving the fastening ring 15 distally relative to the arm portion 20, the arm portion 20 in the open state (see FIG. 4(a)) can be fastened by the fastening ring 15 against the self-expanding force. This causes the arm portion 20 to be in a closed state (see FIG. 4(b)). In addition, by moving the fastening ring 15 backward relative to the arm portion 20, the arm portion 20 opens due to the self-expanding force. The annular fastening ring 15 may be a full annular shape in which the entire peripheral surface is continuous in the circumferential direction, or a partial annular shape in which a notch or slit is provided in a part of the circumferential direction.

[0023] The arm body 22 of the arm portion 20 is formed to be wider than the base end 21, and the tightening ring 15 is restricted from moving forward beyond the base end 21. The tightening ring 15 moves forward and backward relative to the arm portion 20 in a length region between the locking portion 25 and the arm body 22. Then, as shown in FIG. 4(b), the tightening ring 15 fits into the boundary between the arm body 22 and the base end 21, whereby the tightening ring 15 is locked to the arm portion 20 and the clip 10 is locked in the closed state. As a result, the clip 10 is ligated.

[0024] The locking portion 25 of the clip 10 has a receiving portion 27 having a space 27a therein for receiving the clip connecting portion 63 at the tip of the operating wire 61, and a protrusion 26 formed to protrude inward on the base end side of the receiving portion 27. The receiving portion 27 receives the clip connecting portion 63 in the space 27a, whereby the clip 10 and the operating wire 61 are connected to each other.

[0025] The protrusions 26 are claws that are elastically deformed and released as they are pushed apart by the clip connecting parts 63, and then elastically restored to their original state to engage with and hold the clip connecting parts 63. The protrusion 26 is a portion disposed on the proximal side of the receiving portion 27 and closes a part or the whole of the space 27a in an openable manner. The shape, position, and size of the protrusion 26 are not particularly limited. For example, the receiving portion 27 may be formed in an annular shape, and the protrusion 26 may be formed in a shape protruding radially inward from the peripheral surface of the annular receiving portion 27. Alternatively, as described below, the receiving portion 27 may be composed of a base portion 25a such as an annular shape and a protruding piece portion 25b protruding proximally from the base portion 25a, and the protrusion 26 may be formed at the tip of the protruding piece portion 25b.

[0026] The locking portion 25 includes a base portion 25a connected to the base end of the arm portion 20, and a plurality of protruding pieces 25b formed to protrude from the base portion 25a toward the base end side and constituting a receiving portion 27. The protrusions 26 are formed on the proximal tip portions of the protruding pieces 25b, respectively.

[0027] The clip connecting portion 63 of the operation wire 61 is housed in a space 27a surrounded by the base 25a, the protruding piece portion 25b, and the protrusion 26. The inner diameter of the base 25a is smaller than the maximum outer diameter of the clip connecting portion 63, and the base 25a restricts the forward movement of the clip connecting portion 63. The protrusion 26 restricts the clip connecting portion 63 housed in the space 27a from moving backward. The clip connecting portion 63 housed in the space 27a may be restrained in the tip-proximal end direction by the base 25a and the protrusion 26, so that the forward and backward movement of the clip connecting portion 63 inside the space 27a is restricted, or the clip connecting portion 63 may be able to move slightly forward and backward in the axial direction inside the space 27a.

[0028] The clip connecting portion 63 is, for example, a block-like one. The clip connecting portion 63 being "block-like" means that the clip connecting portion 63 is thicker than the locking portion 25, and when the clip connecting portion 63 is connected to the locking portion 25 and is removed from the locking portion 25, the deformation of the clip connecting portion 63 is sufficiently smaller than the deformation of the locking portion 25. The specific shape of the block-like clip connecting portion 63 is not particularly limited, and may be a shape in which the distal side portion and the proximal end portion are tapered toward the distal end and the proximal end, respectively, as shown in FIG. 3 etc., or may be a columnar or spherical shape. For example, the cross-sectional shape of the clip connector 63 is a polygon, preferably a regular polygon. As an example, the clip connector 63 has a regular octagonal cross-section.

[0029] A plurality of protruding pieces 25b are arranged facing each other on the locking portion 25. The number of protruding pieces 25b is not limited, but it is preferable that the number is less than the number of outer circumferential flat surfaces of the clip connecting portion 63 having a polygonal cross section. Specifically, the locking portion 25 has, for example, a pair (two) of protruding pieces 25b. The protruding pieces 25b are plate-shaped and have a width narrower than the diameter of the clip connecting portion 63. The pair of protruding pieces 25b are provided at positions that allow them to face each other on the outer circumferential plane of the clip connecting part 63. More specifically, the two protruding pieces 25b are provided at positions that face each other by 180 degrees on the base 25a of the locking part 25. The distance between the protruding pieces 25b is set to a dimension that allows the protruding pieces 25b to be in close contact with or in close proximity to the outer circumferential plane of the clip connecting part 63. However, the present invention is not limited to this example, and the three protruding pieces 25b may be disposed facing each other at equal intervals of 120 degrees. In this case, the expansion of the diameter of the locking portion 25 means that the locking portion 25 is deformed in a direction in which the opposing intervals between the three protruding pieces 25b are expanded.

[0030] When the clip connecting portion 63 is connected to the clip 10 (clip body 11), the multiple protruding portions 25b are arranged in close contact with or adjacent to the clip connecting portion 63 so as to surround the outer circumferential plane of the clip connecting portion 63 received in the receiving portion 27. As a result, when the clip connecting portion 63 is rotated with torque, the outer circumferential plane of the clip connecting portion 63 rotates the protruding portions 25b about the axis, and torque is applied to the entire clip body 11 via the locking portion 25.

[0031] The protrusions 26 formed on the proximal tip of the protruding piece 25b are arranged on a circumference concentric with the base 25a and are formed in a partial arc shape. Each protrusion 26 has a partial arc shape with a central angle of about 120 degrees, and is formed so that two protrusions 26 can hold about two-thirds of the circumference.

[0032] 1, the treatment device main body 50 includes, in addition to the above-mentioned operation wire 61 and sheath 30, a hand operation section 90 provided on the proximal side of the sheath 30 and connected to the proximal end of the operation wire 61. The clip 10 is detachably connected to the distal end of the operation wire 61 via a clip connecting section 63, and is opened and closed by operating the hand operation section 90.

[0033] As shown in Figs. 1 and 2, the sheath 30 of the treatment tool main body 50 is a long, flexible tubular member. The sheath 30 is longer than the forceps hole of the endoscope used with the endoscopic clip device 100. The sheath 30 can be formed, for example, of a coil layer (not shown) in which a metal wire is wound long. An inner layer (not shown) made of a fluorine-based polymer may be provided on the inner peripheral surface of the coil layer. The sheath 30 may also be a coil layer in which a resin wire is wound, or a flexible resin tube. In this embodiment, a metal ferrule is attached to the distal end of the sheath 30, for example.

[0034] The inner diameter of the sheath 30 is large enough to slidably accommodate the sleeve 40. The sheath 30 can accommodate the clip 10 in a closed arm state. More specifically, the inner diameter of the sheath 30 is, for example, not less than 100 μm and not more than 2400 μm. The thickness of the sheath 30 is, for example, not less than 100 μm and not more than 350 μm. This can improve the flexibility of the sheath 30.

[0035] The hand operation unit 90 is for opening and closing the pair of arms 20, and is disposed on the proximal side of the treatment instrument body 50. The hand operation unit 90 includes, for example, a shaft portion 98 through which the operation wire 61 is inserted, a finger ring 92 provided at the proximal end of the shaft portion 98, and a slider 94 to which the proximal end of the operation wire 61 is connected and which moves forward and backward relative to the shaft portion 98. The operation wire 61 is inserted slidably through the shaft portion 98. The practitioner inserts, for example, his thumb into the finger ring 92 and pinches the slider 94 between the other two fingers to drive it forward and backward along the longitudinal direction of the shaft portion 98. This causes the operation wire 61 to advance or retreat relative to the hand operation unit 90. The proximal end of the sheath 30 is fixed to the hand operation unit 90, and as described above, the operation wire 61 is inserted through the sheath 30 so as to be able to advance and retreat in the axial direction, so that the tip of the operation wire 61 advances or retreats relative to the sheath 30 in conjunction with the forward and backward movement of the slider 94. As a result, the locking portion 25 of the clip 10 is driven to advance and retreat, and the pair of arms 20 opens and closes. More specifically, as shown in Fig. 4(b), when the operation wire 61 is pulled proximally, the pair of arms 20 are closed. Conversely, as shown in Fig. 4(a), when the operation wire 61 is pushed distally, the pair of arms 20 are opened.

[0036] The operation wire 61 is inserted through the inside of the sheath 30 and the inside of the proximal operation unit 90 so as to be able to advance and retreat in the axial direction. The operation wire 61 is made of a metal material with high rigidity, such as stainless steel, a steel wire with a corrosion-resistant coating, titanium, or a titanium alloy. A resin layer (not shown) made of a fluoropolymer may be provided so as to cover the outer circumferential surface of the operation wire 61.

[0037] The distal end of the operating wire 61 is provided with the above-mentioned sleeve 40, which is a cylindrical sleeve disposed inside the sheath 30 and has a holding portion 43 at its distal end capable of holding a fastening portion (fastening ring 15). The inner diameter of at least a part of the sleeve 40 is smaller than the outer diameter of the locking portion 25 when the clip connecting portion 63 is capable of being detached from the receiving portion 27. The sleeve 40 is a member that restricts the backward movement of the fastening ring 15 relative to the sheath 30 and transitions the clip 10 from an open state to a closed state. The sleeve 40 can be stored inside the sheath 30, and a part of the sleeve 40 can be protruded from the sheath 30 by advancing the operating wire 61.

[0038] 3 and other figures, the sleeve 40 has a diameter-reducing step portion 47 and a sleeve body 41 in addition to the holding portion 43. The holding portion 43 is provided at the distal end of the sleeve 40 and is elastically self-expandable. The holding portion 43 holds the fastening portion (fastening ring 15) when the clip connecting portion 63 is released from the locking portion 25, and restricts the fastening portion from moving backward relative to the sheath 30. The diameter-reducing step portion 47 is provided on the proximal side of the holding portion 43.

[0039] The sleeve body 41 is provided further proximal than the reduced diameter step portion 47 . The inner diameter of the sleeve body 41 is smaller than the outer diameter of the locking portion 25 when the clip connecting portion 63 is able to detach from the receiving portion 27. Therefore, in a state in which the locking portion 25 and the clip connecting portion 63 are connected to each other and in a state in which the protrusion 26 and the protruding piece portion 25b are housed in the sleeve body 41, the sleeve body 41 restricts the protruding piece portion 25b from expanding in diameter, thereby restricting the clip connecting portion 63 from detaching from the receiving portion 27. On the other hand, by retracting the protruding piece 25 b to the proximal end of the sleeve body 41 , the protruding piece 25 b is expanded in diameter sufficiently to allow the clip connecting portion 63 to be detached from the receiving portion 27 .

[0040] The holding portion 43 is configured to be capable of expanding or contracting in diameter. When the sleeve 40 is housed in the sheath 30 and constrained by the sheath 30, the holding portion 43 is deformed to be smaller in diameter than in the natural state where it is not constrained by the sheath 30, and the outer diameter is smaller than the inner diameter of the sheath 30. Then, as shown in FIG. 2 etc., the holding portion 43 of the sleeve 40 protrudes distally from the sheath 30, so that the holding portion 43 elastically returns to its natural state. In the natural state, the holding portion 43 has a larger diameter than the inner diameter of the sheath 30. Also, the inner diameter of the holding portion 43 in the natural state (when expanded) is equal to or larger than the outer diameter of the fastening ring 15. Therefore, the fastening ring 15 can enter the inside of the holding portion 43 when the diameter is expanded. Then, by the fastening ring 15 entering the inside of the holding portion 43, the holding portion 43 holds the fastening ring 15 and restricts the backward movement of the holding portion 43 relative to the sheath 30.

[0041] The diameter-reducing step portion 47 is formed in a tapered shape that reduces in diameter toward the proximal side between the sleeve body 41 and the holding portion 43. The material of the sleeve 40 is not limited to a specific material as long as it is a member that can be reduced in diameter by an external force. For example, a metal material, a resin, or an elastomer such as rubber can be used. In this embodiment, the sleeve 40 is a cylindrical body (pipe) made of a metal material such as stainless steel.

[0042] As described above, the transmission portion 73 is a member that connects the movable member 71 and the sleeve 40 , and is a coil spring that transmits the forward and backward forces of the operation wire 61 to the sleeve 40 .

[0043] The transmission section 73 can be made of a coil made of a metal or resin wire wound in a spiral, or an elastomer such as rubber. As the wire, a metal wire such as stainless steel or tungsten can be preferably used. The transmission part 73 is a coil wound with an unequal pitch, with the winding pitch at both ends fixed to the movable member 71 and the sleeve 40 being smaller and the winding pitch at the middle part being larger than those at both ends. More specifically, both ends of the transmission part 73 are wound in a dense manner with adjacent winding loops in contact with each other, and the middle part of the transmission part 73 is wound with a pitch winding with adjacent winding loops spaced apart from each other. In this embodiment, the outer diameter of the transmission part 73 is set to a dimension slightly smaller than the inner diameter of the sheath 30, for example.

[0044] The sleeve 40 is a cylindrical member fixed to the transmission section 73, and the operation wire 61, the transmission section 73, the movable member 71, and the sleeve 40 are arranged coaxially with the sheath 30. The sleeve body 41 of the sleeve 40 is accommodated in the transmission section 73. The distal end of the transmission section 73 abuts against the proximal side of the reduced diameter step section 47. The distal end of the transmission section 73 is fixed to the periphery of the sleeve body 41, and the proximal end of the transmission section 73 is fixed to the movable member 71. A part of the intermediate section (the intermediate section between the distal end and the proximal end) of the transmission section 73 is attached to the periphery of the sleeve body 41 in a non-fixed manner. The distal end of the transmission section 73 is fixed to the periphery of the sleeve body 41 by adhesive, metal brazing such as solder, or welding. Similarly, the proximal end of the transmission section 73 is fixed to the movable member 71 by adhesive, metal brazing such as solder, or welding.

[0045] As described above, the movable member 71 is movable forward and backward in the axial direction relative to the operation wire 61. More specifically, as shown in FIG. 3 etc., in this embodiment, the movable member 71 is fitted onto the operation wire 61. As a result, when the manipulation wire 61 is advanced or retracted inside the sheath 30, the manipulation wire 61 can be advanced or retracted while remaining positioned near the axis of the sheath 30. Therefore, even when the sheath 30 is inserted into a forceps hole of a curved endoscope (not shown), the manipulation wire 61 is positioned approximately on the center line of the forceps hole, so that the path length of the manipulation wire 61 does not change, and unintentional protrusion of the clip connecting portion 63 and the clip 10 from the sheath 30 is suppressed.

[0046] In addition, in the present embodiment, the movable member 71 slides in the axial direction relative to the operation wire 61. More specifically, in the present embodiment, the advancement assistance section includes a structure in which the operation wire 61 and the movable member 71 are in frictional contact with each other (a structure that slides). According to this configuration, when the operating wire 61 is pushed distally, the sleeve 40 also advances following the advancement of the clip 10 (the fastening portion and the clip body 11), and the state in which the holding portion 43 holds the fastening portion can be well maintained. Therefore, when the operating wire 61 is subsequently pulled proximally, the clip 10 can be released from the operating wire 61 more reliably. However, in the present invention, the movable member 71 may be capable of advancing and retreating without contacting the operation wire 61, for example.

[0047] The frictional force between the operation wire 61 and the movable member 71 is preferably greater than the frictional force between the transmission portion 73 and the sheath 30, for example. With this configuration, the frictional force between the operating wire 61 and the movable member 71 can be sufficiently secured, so that when the operating wire 61 is pushed distally, the sleeve 40 can be pushed forward effectively by the operating wire 61.

[0048] The clip connecting portion 63 is, for example, a block having a larger diameter than the operation wire 61, and is fixed to the distal end of the operation wire 61. The movable member 71 is, for example, formed in a cylindrical shape, and the operation wire 61 is inserted into the inner cavity of the cylindrical movable member 71. The outer diameter and the inner diameter of the movable member 71 are each constant regardless of, for example, the position in the axial direction. The inner diameter of the movable member 71 is set to, for example, a dimension larger than the outer diameter of the operation wire 61. This allows the movable member 71 to advance and retreat smoothly relative to the operation wire 61. The outer diameter of the movable member 71 is formed, for example, slightly smaller than the inner diameter of the sheath 30. This realizes a structure in which the movable member 71 can advance and retreat relative to the operation wire 61, while allowing the operation wire 61 to advance and retreat while remaining positioned near the axis of the sheath 30 by the movable member 71.

[0049] Here, the treatment tool main body 50 further includes a biasing member (in the case of this embodiment, a second coil spring 76 described later) that constantly biases the movable member 71 relatively toward the distal side with respect to the operation wire 61. More specifically, in this embodiment, the advancement assist portion includes a biasing member that constantly biases the movable member 71 distally relative to the operation wire 61. With this configuration, when the operating wire 61 is pushed distally due to an action of pressing the clip body 11 against biological tissue or due to an erroneous operation after ligation of the clip 10, the sleeve 40 can more reliably advance in conjunction with the advancement of the clip 10 (the fastening portion and the clip body 11).

[0050] In addition, the treatment tool main body 50 further includes a proximal fixed portion 65 that is fixed to the operation wire 61 on the proximal side of the movable member 71 . The biasing member (second coil spring 76) is interposed between the proximal fixed portion 65 and the movable member 71, and receives a reaction force from the proximal fixed portion 65 to bias the movable member 71 distally. According to such a configuration, the biasing force of the second coil spring can be sufficiently ensured, so that the forward movement of the movable member 71 can be more reliably assisted by the biasing member (second coil spring 76).

[0051] In the case of this embodiment, the biasing member is a second coil spring 76 that is fitted onto the operation wire 61. In other words, the operation wire 61 is inserted into the inner cavity of the second coil spring 76. The proximal end of the second coil spring 76 is in contact with the distal end surface of the proximal side fixed part 65, and the second coil spring 76 receives a reaction force from the distal end surface to bias the movable member 71 toward the distal side. This allows the biasing member (second coil spring 76) to smoothly follow the bending of the sheath 30. Therefore, for example, even in a state in which the sheath 30 is inserted into the forceps hole of a curved endoscope (not shown), the second coil spring 76 can smoothly assist the forward movement of the movable member 71. However, in the present invention, the biasing member is not limited to the second coil spring 76, and may be any member that can constantly bias the movable member 71 distally relative to the operation wire 61.

[0052] As shown in FIG. 2, the outer diameter of the second coil spring 76 is smaller than the outer diameter of the coil spring (transmission portion 73), for example. According to such a configuration, friction between the second coil spring 76 and the inner peripheral surface of the sheath 30 can be suppressed, so that the biasing force of the biasing member (second coil spring) can be fully exerted.

[0053] The spring constant of the second coil spring 76 is, for example, smaller than the spring constant of the coil spring (transmission portion 73). That is, the biasing force of the second coil spring 76 is smaller than the biasing force of the coil spring (transmission portion 73). With this configuration, the biasing force of the biasing member (second coil spring) is appropriately suppressed, and therefore, the holding portion 43 and the fastening portion are prevented from being unintentionally biased (advanced) toward the distal side by the biasing member, which would result in the clip 10 being ligated. Note that "ligation" here does not necessarily mean complete ligation (a state in which the clip body 11 is irreversibly locked by the fastening portion), but rather means a state in which the fastening portion and the clip body 11 at least move forward and backward together.

[0054] Furthermore, as shown in FIG. 2, the treatment device main body 50 includes, for example, a distal fixed portion 67 that is fixed to the operation wire 61 on the distal side of the movable member 71. Then, at a position where the clip connecting portion 63 is housed within the sleeve 40 , the forward movement of the movable member 71 is restricted by the distal fixing portion 67 . More specifically, the forward movement of the movable member 71 is restricted by the distal fixing portion 67, whereby the relative forward movement of the movable member 71 and therefore the sleeve 40 with respect to the operation wire 61 is restricted. This makes it possible to prevent the clip connecting portion 63 from being completely exposed from the sleeve 40 even if the movable member 71 and therefore the sleeve 40 move forward relatively to the operation wire 61. In other words, while the movable member 71 is configured to be movable relative to the operation wire 61, a desired positional relationship between the movable member 71 and therefore the sleeve 40 and the operation wire 61 can be maintained. Note that, here, "the position where the clip connecting portion 63 is contained within the sleeve 40" may be a position where at least a portion of the clip connecting portion 63 is contained within the sleeve 40. In other words, in a state where the forward movement of the movable member 71 is restricted by the distal fixation portion 67, it is sufficient that at least the entire clip connecting portion 63 is not exposed from the sleeve 40, and a portion of the clip connecting portion 63 may be exposed from the sleeve 40. In addition, here, "the advancement of the movable member 71 is restricted by the distal fixing portion 67" means that the distal fixing portion 67 may directly restrict the advancement of the movable member 71, or may indirectly restrict the advancement of the movable member 71 via another member (for example, the spacer 86 described later).

[0055] Furthermore, the distal fixing portion 67 is formed, for example, with a diameter larger than the inner diameter of the sleeve 40, and when the operating wire 61 is pushed in, the distal fixing portion 67 pushes the sleeve 40 forward. With this configuration, as shown in FIG. 8(a), when connecting the clip connecting portion 63 to the clip 10, the clip connecting portion 63 and the sleeve 40 can be pushed forward (toward the distal end) from the distal end of the sheath 30. In this embodiment, the length dimension of the sleeve 40 in the axial direction is smaller than the distance between the distal end of the distal fixing portion 67 and the distal end of the clip connecting portion 63 . 8(a), when the distal fixing portion 67 pushes the sleeve 40 distally, the distal end of the clip connecting portion 63 can be made to protrude from the distal end of the sleeve 40. Therefore, the clip connecting portion 63 can be well connected to the locking portion 25 of the clip 10 in the clip cartridge 200 described later.

[0056] More specifically, in this embodiment, the proximal end of the distal fixing portion 67 is configured to restrict the advancement of the movable member 71, and the distal end of the distal fixing portion 67 is configured to push the sleeve 40 forward. Therefore, for example, by adjusting the axial distance between the proximal end of the distal fixing portion 67 and the distal end of the clip connecting portion 63, it is possible to adjust the position at which the relative advancement of the movable member 71 with respect to the operating wire 61 is restricted when the clip connecting portion 63 is contained within the sleeve 40. Furthermore, for example, by adjusting the distance in the axial direction between the distal end of the distal fixing portion 67 and the distal end of the clip connecting portion 63, the amount of protrusion of the clip connecting portion 63 from the distal end of the sleeve 40 when the distal fixing portion 67 pushes the sleeve 40 distally can be adjusted.

[0057] Here, as shown in FIG. 3, the treatment tool body 50 further includes, for example, a spacer 86 interposed between the distal fixed portion 67 and the movable member 71. The spacer 86 is formed to have a smaller diameter than the distal fixing portion 67 . According to this configuration, the distal fixing portion 67 can indirectly restrict the advancement of the movable member 71 via the spacer 86. More specifically, the distal end of the spacer 86 abuts against the proximal end of the distal fixing portion 67, and the distal end of the movable member 71 abuts against the proximal end of the spacer 86, thereby restricting the advancement of the movable member 71. Therefore, for example, by adjusting the length dimension of the spacer 86 in the axial direction, it is possible to adjust the position at which the relative advancement of the movable member 71 with respect to the operation wire 61 is restricted. Therefore, the length dimension of the distal side fixing part 67 in the axial direction can be set shorter, and the distal side fixing part 67 can be prevented from hindering bending of the sheath 30. More specifically, for example, it is possible to realize a configuration in which the distal fixing portion 67 restricts the advancement of the movable member 71 at a position where the above-mentioned clip connecting portion 63 is contained within the sleeve 40, while avoiding the length dimension of the distal fixing portion 67 becoming excessively large in the axial direction, and a configuration in which the clip connecting portion 63 protrudes a desired amount from the distal end of the sleeve 40 when the above-mentioned distal fixing portion 67 pushes the sleeve 40 distally. However, in the present invention, the treatment tool body 50 does not necessarily have to include the spacer 86. When the treatment tool body 50 does not include the spacer 86, for example, the length dimension of the distal fixing portion 67 can be adjusted to realize the above two configurations.

[0058] In the case of this embodiment, the spacer 86 is fitted onto the operation wire 61 , is movable axially back and forth relative to the operation wire 61 , and is not connected to the distal fixed portion 67 and the movable member 71 . According to this configuration, the spacer 86 can advance and retreat in the region between the distal fixed portion 67 and the movable member 71 in response to bending of the sheath 30. Therefore, the spacer 86 can be prevented from impeding bending of the sheath 30.

[0059] More specifically, the spacer 86 is, by way of example, a coil. This ensures good flexibility of the spacer 86, and more reliably prevents the spacer 86 from interfering with the bending of the sheath 30. Furthermore, interference between the spacer 86 and the transmission portion 73 (which is a coil spring) can be suppressed. However, in the present invention, the spacer 86 is not limited to a coil, and may be, for example, a cylindrical member.

[0060] 2, the proximal fixing part 65 and the distal fixing part 67 are set to have, for example, the same shape and the same dimensions as each other. However, in the present invention, the proximal fixing part 65 and the distal fixing part 67 may be set to have, for example, different shapes or different dimensions as each other. In this embodiment, each of the proximal fixing portion 65 and the distal fixing portion 67 is formed in a substantially cylindrical shape. The inner diameter of each of the proximal fixing portion 65 and the distal fixing portion 67 is constant, for example, regardless of the position in the axial direction. The outer diameters of both ends of each of the proximal fixing part 65 and the distal fixing part 67 are constant regardless of, for example, the axial position. On the other hand, the outer diameters of the intermediate parts of each of the proximal fixing part 65 and the distal fixing part 67 are gradually reduced toward, for example, the center (the center of the proximal fixing part 65 or the distal fixing part 67 in the axial direction). In the axial direction, the length dimension of each of the proximal fixation portion 65 and the distal fixation portion 67 is smaller than the length dimension of the spacer 86, for example.

[0061] Each of the second coil spring 76 and the spacer 86 can be made of a coil made of a metal or resin wire wound in a spiral, or an elastomer such as rubber. As the wire, a metal wire such as stainless steel or tungsten can be preferably used. In the present invention, the coil spring (transmission portion 73), the second coil spring 76, and the spacer 86 may be made of the same type of material, or may be made of different types of materials.

[0062] In this embodiment, the wire diameter of the wire material forming the second coil spring 76 is smaller than the wire diameter of the wire material forming the coil spring (transmission portion 73). This makes it possible to appropriately suppress the biasing force of the biasing member (second coil spring 76).

[0063] The outer diameter of the second coil spring 76 is smaller than the outer diameter of the movable member 71 and is also smaller than the outer diameter of the proximal fixed part 65 . As a result, the second coil spring 76, between the proximal fixed portion 65 and the movable member 71, can receive a reaction force from the proximal fixed portion 65 and effectively urge the movable member 71 toward the distal side. In addition, the outer diameter of the spacer 86 is smaller than the outer diameter of the movable member 71 and also smaller than the outer diameter of the distal fixed portion 67 . This allows the spacer 86 to effectively restrict the forward movement of the movable member 71 between the movable member 71 and the distal fixed portion 67 .

[0064] 2, from the distal end side, the distal fixed part 67, the spacer 86, the movable member 71, the second coil spring 76, and the proximal fixed part 65 are inserted onto the operation wire 61 in this order. Of these, the distal fixed part 67 and the proximal fixed part 65 are each fixed to the operation wire 61 as described above. Meanwhile, the spacer 86 and the movable member 71 are each movable forward and backward in the axial direction relative to the operation wire 61 as described above. The second coil spring 76 is expandable and contractible between the proximal fixed part 65 and the movable member 71. Additionally, each of the distal fixing portion 67 and the spacer 86 is disposed in the inner cavity of the transmission portion 73 (coil spring).

[0065] In the case of this embodiment, as an example, the length dimension of the movable member 71 in the axial direction is preferably 0.5 mm or more and 3 mm or less, and more preferably 1 mm or more and 2 mm or less. As an example, the length dimension of the distal fixing portion 67 in the axial direction is preferably 0.4 mm or more and 2 mm or less, and more preferably 0.8 mm or more and 1.6 mm or less. As an example, the length dimension of the proximal fixing portion 65 in the axial direction is preferably 0.4 mm or more and 2 mm or less, and more preferably 0.8 mm or more and 1.6 mm or less. As an example, the length dimension of the spacer 86 in the axial direction is preferably 1 mm or more and 5 mm or less, and more preferably 2 mm or more and 4 mm or less.

[0066] Thus, the endoscopic clip device 100 of this embodiment comprises a long sheath 30 capable of accommodating the clip 10, a cylindrical sleeve 40 disposed inside the sheath 30, the sleeve 40 having a holding portion 43 at its distal end capable of holding a fastening portion, an operating wire 61 having a clip connecting portion 63 at its distal end which connects to or detaches from the engaging portion 25 and is inserted through the sheath 30 and the sleeve 40 so as to be movable forward and backward in the axial direction, a movable member 71 which can advance and retreat in the axial direction relative to the operating wire 61, a transmission portion 73 which connects the movable member 71 to the sleeve 40 and is a coil spring which transmits the forward force and backward force of the operating wire 61 to the sleeve 40, and a biasing member (second coil spring 76) which constantly biases the movable member 71 distally relative to the operating wire 61.

[0067] Moreover, the endoscopic clip device 100 according to this embodiment includes a long sheath 30 capable of accommodating a clip 10, a cylindrical sleeve 40 disposed inside the sheath 30, the sleeve 40 having a holding portion 43 at its distal end capable of holding a fastening portion (fastening ring 15), an operating wire 61 having a clip connecting portion 63 at its distal end which connects to or disconnects from the engaging portion 25 and is inserted through the sheath 30 and the sleeve 40 so as to be movable axially forward and backward, a movable member 71 which can advance and retreat in the axial direction relative to the operating wire 61, and a transmission portion which connects the movable member 71 to the sleeve 40 and is a coil spring which transmits the forward and backward forces of the operating wire 61 to the sleeve 40, and the movable member 71 slides axially relative to the operating wire 61.

[0068] A series of procedures for connecting the clip connecting portion 63 of the operation wire 61 to the clip 10 will be described below with reference to Figs. 7(a) to 8(b).

[0069] As shown in FIG. 7( a ), the clip 10 is initially housed in the clip cartridge 200 with the fastening ring 15 attached to the outer periphery of the pair of arm portions 20 . First, as shown in FIG. 7( b ), the sheath 30 of the treatment tool body 50 is inserted into the insertion hole 243 of the outer case 240 of the clip cartridge 200 until the distal end of the sheath 30 abuts against the stopper portion 242 .

[0070] Next, as shown in FIG. 8(a), by pushing the operating wire 61 distally, the clip connecting portion 63 and the holding portion 43 of the sleeve 40 protrude from the sheath 30 toward the distal end and enter the area between the inner case 230 and the insertion hole 243, and the holding portion 43 elastically expands in diameter. More specifically, by pushing the operation wire 61 distally, the operation wire 61 advances relatively to the sleeve 40, and the distal fixing portion 67 abuts against the proximal end of the sleeve 40. By further pushing the operation wire 61 distally from this state, the holding portion 43 of the sleeve 40 is pushed forward by the distal fixing portion 67. At this time, the clip connecting portion 63 protrudes distally from the distal end of the sleeve 40, and the clip connecting portion 63 and the locking portion 25 are connected to each other.

[0071] 8(b), the operating wire 61 is pulled proximally to retract the clip 10 and the sleeve 40 into the sheath 30. At this time, the sleeve 40 enters the sheath 30 while the holding portion 43 is contracting in diameter. Also, the pair of arms 20 of the clip 10 are retracted into the fastening ring 15 while slightly closing, but do not achieve ligation. Thereafter, the sheath 30 is pulled out from the clip cartridge 200. With the above, the loading of the clip 10 into the treatment tool body 50 is completed.

[0072] Next, an example of a series of procedures for fastening the clip 10 to biological tissue using the endoscopic clipping device 100 will be described.

[0073] First, the clip 10 and the operating wire 61 are detachably connected using the technique described above. Then, the clip 10 is housed in the distal end portion of the sheath 30.

[0074] Next, with the clip 10 housed in the sheath 30, the sheath 30 is advanced into the body cavity through the forceps hole of the endoscope. When the distal end of the sheath 30 reaches the vicinity of the biological tissue that needs to be ligated, the operating wire 61 is pushed distally. As a result, as shown in Fig. 4(a), the clip 10 and the fastening ring 15 protrude from the distal end of the sheath 30, and the clip 10 naturally expands to the maximum opening width by its own expansion force.

[0075] At this time, at least the holding portion 43 and the diameter-reducing step portion 47 of the sleeve 40 protrude from the distal end of the sheath 30, and expand to a natural diameter. Next, the position and orientation of the clip 10 are adjusted with respect to the biological tissue to be ligated.

[0076] When the treatment tool main body 50 is torque-rotated, the operation wire 61 and the clip connecting part 63 are torque-rotated in conjunction with each other. Furthermore, since the clip connecting part 63 transmits the torque to the locking part 25, the arm part 20 of the clip 10 is also torque-rotated. This allows the opening direction of the arm part 20 to be directed in a desired direction with respect to the ligation site of the biological tissue.

[0077] After the position and orientation of the clip 10 are determined, the operating wire 61 is pulled proximally while the distal end of the clip 10 is pressed against the ligation site. At this time, the fastening ring 15 abuts against the inner surface of the diameter-reducing step portion 47 and is fitted inside the holding portion 43, so that the retraction movement relative to the sleeve 40 and the sheath 30 is restricted. Furthermore, since the fastening ring 15 is fitted into the holding portion 43, the holding portion 43 is prevented from being deformed by reducing its diameter even if an external force is applied to the holding portion 43, and the holding portion 43 is prevented from being pulled into the sheath 30 even if the operating wire 61 is pulled proximally with a large force.

[0078] When the operation wire 61 is pulled proximally while the clip connecting portion 63 is received in the receiving portion 27, the arm portion 20 closes and grasps the biological tissue. It is also possible to interrupt the retraction while the arm portion 20 is closing and push the operation wire 61 again to open the arm portion 20 again. When the operation wire 61 is further pulled proximally, the tightening ring 15 fits into the arm portion 20 and the clip 10 is locked (FIG. 4(b)). This causes the clip 10 to close and ligate. From this state, when the operating wire 61 is pulled further proximally, the locking portion 25 expands in diameter while pushing the sleeve body 41 apart. More specifically, the clip connecting portion 63, for example, while pushing the opposing gap between the pair of protruding portions 25b apart, frictionally slides against the pair of protruding portions 25b, moves to the base end side, and falls off the receiving portion 27. As a result, the clip 10 is separated (disengaged) from the operating wire 61, and is placed in the body cavity with the biological tissue ligated.

[0079] As described above, the treatment tool body 50 is provided with an advancement assisting portion that assists the advancement of the movable member 71 so as to advance the sleeve 40 following the advancement of the clip body 11 and the fastening portion. According to this configuration, when the operation wire 61 is pushed distally by pressing the clip body 11 against biological tissue or by erroneous operation after ligation of the clip 10, the sleeve 40 can also advance in response to the advancement of the clip 10 (the fastening portion and the clip body 11) (see FIG. 5). Thus, the state in which the holding portion 43 holds the fastening portion can be favorably maintained. Therefore, when the operation wire 61 is pulled proximally to subsequently detach the clip 10 from the operation wire 61, the backward movement of the holding portion 43 and therefore the fastening portion can be more reliably restricted. Thus, the clip 10 can be more reliably detached from the operation wire 61 (see FIG. 6).

[0080] As described above, the movable member 71 is capable of advancing and retreating in the axial direction relative to the operation wire 61. Therefore, when the operation wire 61 is further pulled proximally after the distal end of the sheath 30 restricts the retreat of the holding portion 43 of the sleeve 40, it is possible to suppress (avoid) the transmission portion 73, which is a coil spring, from being extended in the axial direction. Therefore, when the operation wire 61 is erroneously advanced as described above, the sleeve 40 can be immediately advanced together with the operation wire 61. That is, the state in which the holding portion 43 holds the fastening portion can be well maintained. More specifically, when the arm portion 20 of the clip 10 is changed from the open state (FIG. 4(a)) to the closed state (FIG. 4(b)), the operating wire 61 retracts relative to the sleeve 40, but the movable member 71 is capable of advancing and retracting in the axial direction relative to the operating wire 61 and does not follow the retraction of the operating wire 61. Therefore, the separation distance between the sleeve 40 and the movable member 71 in the axial direction is maintained, and extension of the transmission portion 73 in the axial direction can be suppressed (avoided). Furthermore, as described above, the treatment tool main body 50 includes a biasing member (second coil spring 76) that constantly biases the movable member 71 distally relative to the operation wire 61. Therefore, when the arm portion 20 is changed from the open state to the closed state, the operation wire 61 retracts relative to the sleeve 40, but the movable member 71 can be more reliably prevented from following the retraction of the operation wire 61.

[0081] This completes a series of procedures from closing the arms of the clip 10 to detaching the clip connecting portion 63 from the clip 10. By repeating the above procedures, living tissue can be ligated with a large number of clips 10.

[0082] <Modification> Next, a modified example will be described with reference to Fig. 9. Fig. 9 is a cross-sectional view taken along the axis of the sheath 30. The endoscopic clipping device 100 of this modified example differs from the endoscopic clipping device 100 of the above-described embodiment in the respects described below, but in other respects is configured in the same manner as the endoscopic clipping device 100 of the above-described embodiment.

[0083] In this modified example, the treatment tool main body 50 does not have a biasing member (second coil spring 76), and the advancement assistance section is composed only of a structure in which the operating wire 61 and the movable member 71 are in frictional contact (a structure that moves by sliding). Even with this configuration, when the operating wire 61 is pushed distally, the sleeve 40 also advances following the advancement of the clip 10 (the fastening portion and the clip body 11), and the state in which the holding portion 43 holds the fastening portion can be well maintained. Therefore, when the operating wire 61 is subsequently pulled proximally, the clip 10 can be released from the operating wire 61 more reliably. Furthermore, since the movable member 71 is capable of advancing and retreating in the axial direction relative to the operating wire 61, when the operating wire 61 is further pulled proximally after the distal end of the sheath 30 has restricted the retreat of the holding portion 43 of the sleeve 40, the movable member 71 can be prevented from retreating following the operating wire 61.

[0084] In this manner, the endoscopic clip device 100 of this modified example comprises a long sheath 30 capable of accommodating the clip 10, a cylindrical sleeve 40 disposed inside the sheath 30, the sleeve 40 having a holding portion 43 at its distal end capable of holding a fastening portion (fastening ring 15), an operating wire 61 having a clip connecting portion 63 at its distal end which connects to or disconnects from the engaging portion 25 and is inserted through the sheath 30 and the sleeve 40 so as to be movable axially forward and backward, a movable member 71 which can advance and retreat in the axial direction relative to the operating wire 61, and a transmission portion which connects the movable member 71 to the sleeve 40 and is a coil spring which transmits the forward and backward forces of the operating wire 61 to the sleeve 40, and the movable member 71 slides axially relative to the operating wire 61.

[0085] Although the embodiment and modified examples have been described above with reference to the drawings, these are merely examples of the present invention, and various configurations other than those described above can also be adopted.

[0086] Furthermore, the above-described embodiments and modifications can be combined as appropriate without departing from the spirit of the present invention.

[0087] The present embodiment encompasses the following technical ideas. (1) A long sheath capable of housing a clip having a clip body having a plurality of arms for gripping biological tissue and a locking portion provided on a base end side of the arms, and a fastening portion through which the arms are inserted and which advances relative to the arms to fasten the arms to a closed state; A cylindrical sleeve disposed inside the sheath, the sleeve having a holding portion at a distal end portion capable of holding the fastening portion; an operating wire having a clip connecting portion at a distal end thereof that is connected to or separated from the locking portion, and being inserted through the sheath and the sleeve so as to be movable forward and backward in an axial direction; a movable member that is movable in an axial direction relative to the operation wire; a transmission section which is a coil spring connecting the movable member and the sleeve and transmitting the forward force and the backward force of the operation wire to the sleeve; The treatment tool body includes a treatment tool body having a The treatment tool body further includes an advancement assisting portion that assists the advancement of the movable member so as to advance the sleeve in accordance with the advancement of the clip body and the fastening portion, The advancement assistance portion advances the movable member to advance the sleeve in accordance with the advancement of the clip body and the fastening portion when the operating wire is pushed distally after the operating wire has been pulled proximally from the point in time when the retraction of the holding portion is restricted by the distal end of the sheath during the ligation operation of the clip. (2) The clip device for an endoscope according to (1), wherein the movable member is fitted onto the operating wire. (3) The clip device for an endoscope according to (1) or (2), wherein the treatment tool body further comprises a biasing member that constantly biases the movable member distally relative to the operating wire. (4) The treatment instrument body further includes a proximal fixing portion fixed to the operation wire on a proximal side of the movable member, The clip device for an endoscope described in (3) above, wherein the biasing member is interposed between the proximal fixed portion and the movable member, and biases the movable member distally by receiving a reaction force from the proximal fixed portion. (5) The clip device for an endoscope according to (3) or (4), wherein the biasing member is a second coil spring fitted onto the operating wire. (6) The clip device for an endoscope according to (5), wherein the outer diameter of the second coil spring is smaller than the outer diameter of the coil spring. (7) The clip device for an endoscope according to (5) or (6), wherein the spring constant of the second coil spring is smaller than the spring constant of the coil spring. (8) The treatment instrument body further includes a distal fixing portion fixed to the operation wire on a distal side of the movable member, The clip device for an endoscope according to any one of (1) to (7), wherein the forward movement of the movable member is restricted by the distal fixing portion at a position where the clip connecting portion is contained within the sleeve. (9) The distal fixation portion is formed to have a diameter larger than an inner diameter of the sleeve, The clip device for an endoscope according to (8), wherein the distal fixing portion pushes the sleeve forward when the operating wire is pushed in. (10) The treatment instrument body further includes a spacer interposed between the distal fixed portion and the movable member, The clip device for an endoscope according to (8) or (9), wherein the spacer is formed with a smaller diameter than the distal fixing portion. (11) The clip device for an endoscope described in (10) wherein the spacer is inserted around the operating wire, is movable axially back and forth relative to the operating wire, and is unconnected to the distal fixed portion and the movable member. (12) The clip device for an endoscope according to (10) or (11), wherein the spacer is a coil. (13) The clip device for an endoscope according to any one of (1) to (12), wherein the movable member slides in the axial direction relative to the operating wire. (14) The clip device for an endoscope according to claim 13, wherein the frictional force between the operating wire and the movable member is greater than the frictional force between the transmission portion and the sheath.

[0088] <1> a long sheath capable of housing a clip having a clip body having a plurality of arm portions for gripping biological tissue and a locking portion provided on a base end side of the arm portions, and a fastening portion through which the plurality of arm portions are inserted and which advances relative to the plurality of arm portions to fasten the plurality of arm portions to a closed state; A cylindrical sleeve disposed inside the sheath, the sleeve having a holding portion at a distal end portion capable of holding the fastening portion; an operating wire having a clip connecting portion at a distal end thereof that is connected to or separated from the locking portion, and being inserted through the sheath and the sleeve so as to be movable forward and backward in an axial direction; a movable member that is movable in an axial direction relative to the operation wire; a transmission section which is a coil spring connecting the movable member and the sleeve and transmitting the forward force and the backward force of the operation wire to the sleeve; a biasing member that constantly biases the movable member toward a distal side relative to the operation wire; A clip device for an endoscope comprising a treatment tool body having the following features. <2> a long sheath capable of housing a clip having a clip body having a plurality of arm portions for gripping biological tissue and a locking portion provided on a base end side of the arm portions, and a fastening portion through which the plurality of arm portions are inserted and which advances relative to the plurality of arm portions to fasten the plurality of arm portions to a closed state; A cylindrical sleeve disposed inside the sheath, the sleeve having a holding portion at a distal end portion capable of holding the fastening portion; an operating wire having a clip connecting portion at a distal end thereof that is connected to or separated from the locking portion, and being inserted through the sheath and the sleeve so as to be movable forward and backward in an axial direction; a movable member that is movable in an axial direction relative to the operation wire; a transmission section which is a coil spring connecting the movable member and the sleeve and transmitting the forward force and the backward force of the operation wire to the sleeve; The treatment tool body includes a treatment tool body having a The movable member slides in the axial direction relative to the operating wire. [Explanation of symbols]

[0089] 10 Clips 11 Clip body 15 Fastening ring (fastening part) 20 Arm section 21 Proximal end 22 Arm body 23 Claw part 25 Locking part 25a base 25b Projection piece 26 Protrusion 27 Receptor 27a Space 30 Sheath 40 Sleeve 41 Sleeve body 43 Holding part 47 Reduced diameter step 50 Treatment tool body 61 Control wire 63 Clip connection part 65 Proximal fixation part 67 Distal fixation part 71 Movable parts 73 Transmission section 76 Second coil spring (biasing member) 86 Spacer 90 Handheld operation unit 92 Finger Ring 94 Slider 98 Shaft 100 Endoscopic clipping device 230 Inner Case 240 Outer case 242 Stopper part 243 Insertion hole 200 Clip Cartridge

Claims

1. a long sheath capable of housing a clip having a clip body having a plurality of arm portions for gripping biological tissue and a locking portion provided on a base end side of the arm portions, and a fastening portion through which the plurality of arm portions are inserted and which advances relative to the plurality of arm portions to fasten the plurality of arm portions to a closed state; A cylindrical sleeve disposed inside the sheath, the sleeve having a holding portion at a distal end portion capable of holding the fastening portion; an operating wire having a clip connecting portion at a distal end thereof that is connected to or separated from the locking portion, and being inserted through the sheath and the sleeve so as to be movable forward and backward in an axial direction; a movable member that is movable in an axial direction relative to the operation wire; a transmission section which is a coil spring connecting the movable member and the sleeve and transmitting the forward force and the backward force of the operation wire to the sleeve; The treatment tool body includes a treatment tool body having a The treatment tool body further includes an advancement assisting portion that assists the advancement of the movable member so as to advance the sleeve in accordance with the advancement of the clip body and the fastening portion, The advancement assistance portion advances the movable member to advance the sleeve in accordance with the advancement of the clip body and the fastening portion when the operating wire is pushed distally after the operating wire has been pulled proximally from the point in time when the retraction of the holding portion is restricted by the distal end of the sheath during the ligation operation of the clip.

2. The clip device for an endoscope according to claim 1 , wherein the movable member is fitted onto the operating wire.

3. 3. The clip device for an endoscope according to claim 1, wherein the treatment tool body further comprises a biasing member that constantly biases the movable member distally relative to the operation wire.

4. The treatment instrument body further includes a proximal fixed portion fixed to the operation wire on a proximal side of the movable member, The clip device for an endoscope according to claim 3, wherein the biasing member is interposed between the proximal fixed portion and the movable member, and biases the movable member distally by receiving a reaction force from the proximal fixed portion.

5. 5. The clip device for an endoscope according to claim 4, wherein the biasing member is a second coil spring fitted onto the operating wire.

6. The clip device for an endoscope according to claim 5 , wherein an outer diameter of the second coil spring is smaller than an outer diameter of the coil spring.

7. The clip device for an endoscope according to claim 5 , wherein the spring constant of the second coil spring is smaller than the spring constant of the coil spring.

8. The treatment instrument body further includes a distal fixed portion fixed to the operation wire on a distal side of the movable member, The clip device for an endoscope according to claim 3 , wherein the forward movement of the movable member is restricted by the distal fixing portion at a position where the clip connecting portion is housed within the sleeve.

9. The distal fixation portion is formed to have a diameter larger than an inner diameter of the sleeve, The clip device for an endoscope according to claim 8, wherein the distal fixing portion pushes the sleeve forward when the operating wire is pushed in.

10. The treatment tool body further includes a spacer interposed between the distal fixed portion and the movable member, The clip device for an endoscope according to claim 9, wherein the spacer is formed to have a smaller diameter than the distal fixing portion.

11. The clip device for an endoscope according to claim 10, wherein the spacer is fitted onto the operating wire, is movable axially back and forth relative to the operating wire, and is unconnected to the distal fixed portion and the movable member.

12. The clip device for an endoscope according to claim 10, wherein the spacer is a coil.

13. The clip device for an endoscope according to claim 1 or 2, wherein the movable member slides in the axial direction relative to the operation wire.

14. The clip device for an endoscope according to claim 13, wherein a frictional force between the operating wire and the movable member is greater than a frictional force between the transmission portion and the sheath.

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